HG/T 2693-1995 Determination of chemical composition of carbon monoxide high temperature shift catalyst
Some standard content:
Chemical Industry Standard of the People's Republic of China
HG/T2693-95
High Temperature Shift Catalyst for Carbon Monoxide
Determination of Chemical Composition
Published on April 11, 1995
Implemented on January 1, 1996
Published by the Ministry of Chemical Industry of the People's Republic of ChinaChemical Industry Standard of the People's Republic of China
High Temperature Shift Catalyst for Carbon Monoxide
Determination of Chemical Composition
HG/T 2693-95
Replaces HG 1——1427—81
Subject Content and Scope of Application
This standard specifies B107, B107—1, E108, B109, B110--2, B111, B112, B113, B114, B115, B116, B 117, B118, B119 and other carbon monoxide thermal shift catalysts (hereinafter referred to as high-speed shift catalysts) analysis method of the main chemical components.
This standard applies to iron, chromium, potassium oxide, total molybdenum in thermal shift catalysts. Determination of chemical components such as bulk sulfur and ignition loss 2 Reference standards
GB/T601 Preparation of standard solutions for titration analysis (volume analysis) of chemical reagents GB/T603 Preparation of preparations and products used in chemical reagent test methods GB/T6682 Specifications and test methods for water used in analytical laboratories ZB/TG75001 Analysis method for trace sulfur in fertilizer catalysts ZB/TG75003 Analysis method for weight loss on ignition of fertilizer catalysts 3 Reagents and materials
Unless otherwise specified, the purity of the reagents used in this standard is analytically pure: the experimental water should meet the specifications of grade 3 water in GB/T6682.
4 Preparation of test sample
Mix the laboratory sample evenly, take about 40g by quartering, crush and grind in a porcelain mortar until the largest particle size is less than 1mm, take about 20g by quartering, continue to grind until the sample can pass through a 150um test sieve (GB6003), put it in a weighing bottle, cover it, and put the weighing bottle in a desiccator for later use. 5 Preparation of test solution A
5.1 Summary of method
Dissolve the sample in hydrochloric acid, filter to remove acid-insoluble matter, and dilute to a certain volume. 5.2 Reagents and Materials
5.2.1 Hydrochloric acid (GB/T622) solution: 1+1; 5.2.2 Hydrochloric acid (GB/T622) solution: 2+100: 5.2.3 Sulfuric acid (GB/T 625) solution: 1+1. 5.3 Operating Procedure
Weigh 1g of sample (accurate to 0.0001g), place in a 250mL beaker, moisten with water, add 15mL of hydrochloric acid solution (5.2.1) in a fume hood, cover with a cover, heat to dissolve the sample (do not boil). After dissolution, wash the cover with water and burn the inner wall, dilute the sample, and then add 15mL of hydrochloric acid solution (5.2.1) to the sample. —95
to about 80mL, stir well, heat to 60~70℃, filter with slow filter paper into 250mL volumetric flask, wash beaker and filter paper with warm hydrochloric acid solution (5.2.2), wait for the solution in the volumetric flask to cool to room temperature, dilute with water and shake well. This solution is the test filter A,
If the sample is not completely dissolved with hydrochloric acid, 20mL sulfuric acid solution (5.2.3) can be used to heat it to dissolve it. The operation steps are the same as above. 6 Determination of iron content by complexometric titration
61 Fangsongti Tuo
Under the conditions of pH 1.3~2.0 and temperature 60~70℃, use sulfosalicylic acid as an indicator and disodium ethylenediaminetetraacetic acid (hereinafter referred to as EDTA) standard titration solution to titrate the trivalent iron in the test solution. The divalent iron is pre-oxidized to trivalent iron with ammonium persulfate and titrated together.
6.2 Reagents and materials
6.2.1 Ammonium perchlorate (GB/T 655):
6.2.2 Dihydrate (GB/T631) solution: 1+1:
6.2.3 Acid (GB/T622) solution: 1+1;
6.2.4 Chloroacetic acid solution: 189 g/L;
6. 2.5 EDTA (GB/T 1401) standard titration solution: c (EDTA)=0. 02 mol)/L: prepared according to GB/T 601,6.2.6 5-Phosphorus salicylic acid (GB/T10705) solution: 200 g/L.6.3 Analytical steps
Pipette 10±0.02mL test solution A, cover it in a 250mL beaker, add 15mL water, and add ammonia solution (6.2.2) dropwise while stirring until a small amount of precipitation appears in the solution. Keep for 1 minute, add 1~2 drops of hydrochloric acid solution (6.2.3) to dissolve the precipitate, add 10mL oxyacetic acid solution (6.2.4) and 150mL water, heat the solution to 70~75℃, add about 0.05g ammonium persulfate (6.2.1), 10 5-sulfosalicylic acid solution (6.2.6), and titrate with EDTA standard solution (6.2.5) while it is hot. Titrate until the solution changes from purple-red to slightly green (the temperature should not be lower than 60℃ when approaching the end point). 6.4 Expression of analysis results
The iron content (X) expressed as the percentage of ferric oxide is calculated according to formula (1): X
V, - c, × 0. 079 85
Wherein: V, volume of EDTA standard titration solution. mL; c,-actual concentration of EDTA standard titration solution, mol/L; × 100
mg——mass of sample (5.3), gi0.07985-m—mass of ferric oxide expressed in grams equivalent to 1.00mL EDTA standard titration solution (c(EDTA)=1.000mol/L),
6.5 Allowable error
The absolute value of the difference between two parallel determination results should not be greater than 0.4%, 7 Determination of chromium content by ammonium ferrous sulfate titration method 7.1 Summary of the method
The sample is dissolved in sulfuric acid and phosphoric acid mixed acid, and the trivalent chromium is oxidized to hexavalent chromium with ammonium persulfate in the presence of silver nitrate. It is titrated with ammonium ferrous sulfate using phenylanthranilic acid as an indicator. 7.2 Reagents and materials
7.2.1. Ammonium persulfate (GB/T655):
HG / T 2693 —93
7.2.2 Sulfur-phosphorus acid mixture: slowly inject 200mL sulfuric acid (GB/T625) into 300mL water, add 100mL phosphoric acid (GB/T 1282) after cooling and mix.
7.2.3 Silver nitrate (GB/T670) solution: 25g/L, stored in a brown bottle. 7.2.4 Sodium chloride (GB/T 1266) solution: 50g/L:7,2.5 Ammonium ferrous sulfate (GB/T661) standard titration solution: 2. ((NH),Fe(SO4))=0.1mol/L; prepared according to GB/T601.
7.2.6 Anthranilic acid indicator solution: 28/L, weigh 1.0g of anthranilic acid, dissolve it in 48mL of sodium hydride (GB/T629) solution (4g/L), dilute with water to 500mL,
7.3 Analysis steps
Weigh 0.5g of sample (accurate to 0.0001g), place it in a 400mL beaker, moisten it with water, add 30mL of sulfuric acid (7.2.2), cover with a watch glass, and heat until dissolved. Dilute with water to about 200 mL, add 5 mL of silver nitrate solution (7.2.3), 2-3 g of ammonium peroxide (7.2.1), and heat to boiling. When the solution turns red with a strong acid color (if the red color is not obvious, it indicates that the sample contains very little manganese, and then add manganese dioxide (HG/T 3-1081) solution (200 g/L) in advance), continue heating and boiling until large bubbles appear for 5 min to destroy excess oxidants, add 5 mL of sodium chloride solution (7.2.4), and boil for 5-8 min. min, cool to room temperature with running water. Titrate with standard ammonium ferrous sulfate solution (7.2.3) until light yellow-green, add 34 drops of phenyl anthranilic acid indicator solution (7.2.6), and continue titrating until the solution changes from purple to light green. 7.4 Expression of analysis results
The chromium content (X,) expressed as the mass percentage of chromium oxide is calculated according to formula (2): X
Vz+c, ×0. 025 33
Wu: V is the volume of standard ammonium ferrous sulfate solution, mL; x100
c2 is the actual concentration of standard ammonium ferrous sulfate solution, mol/L; the mass of the sample, more
0.02533 and 1.00mL standard ammonium ferrous sulfate solution [(NHFe(SOz)=1.000mol/L) is equivalent to the mass of chromium trioxide expressed in grams. 7.5 Allowable difference
The absolute value of the difference between two parallel determination results should not be greater than 0.2%. 8 Determination of potassium oxide content Flame photometry
8.1 Method summary
In a slightly acidic solution, the iron, chromium and other elements in the test solution are separated by hydrolysis precipitation. Potassium is determined by flame photometry and quantified by the working curve method. The amount of standard comparison solution series and test solution should be controlled to be consistent to eliminate the influence of noise on the determination. 8.2 Reagents and materials
8.2.1 Urea (Urea) (GB/T 695); 8.2.2 Ammonia (GB/T -631) solution: 1+1:82.3 Potassium oxide standard solution (1 mL solution contains 1 mg K,0): Weigh 1.583 potassium chloride (GB/T646) burned to constant weight at 500~600C, dissolve in water, transfer to a 1000mL volumetric flask, dilute to scale with water, mix well, and store in a plastic bottle. 8.2.4 Potassium oxide standard solution. (1 mL solution contains 200 μK,0): Pipette 10.0 mL potassium oxide standard solution (8.2.3) into a 50mL container bottle, dilute to scale with water, shake, 8:3 Instruments
Flame photometer,
&.4 Analysis steps
HG/T 2693—95
8.4.1 Determination
Pipette 50.0mL test solution A, place in a 250mL beaker, add 30mL water, heat to boiling, add ammonia solution (8.2.2) dropwise while stirring, until a small amount of precipitation appears in the solution, keep for 1 minute, add 3.0g of styrene (8.2.1), cover with blood, heat and boil for 20 minutes (add water during boiling to keep the solution volume at 70~80mL), adjust the pH to 7~7.5 with ammonia solution (8.2.2) (test with wide pH test paper), and boil again. 5min, remove and cool to room temperature, transfer to a 100mL volumetric flask, dilute to scale with water, evenly and dry filter, adjust to zero with blank solution according to instrument working conditions, and measure the emission intensity of potassium spectrum line of the filtrate in oxidizing flame
8.4.2 Drawing of working curve
Pull 0, 2.00, 4.00, 6.00, 8.00, 10.00mL potassium oxide standard solution (8.2.4), place in 6 100mL volumetric flasks respectively, add 3.0g of potassium oxide (8.2.1) to each bottle, dilute to scale with water after dissolving, and shake well. The solution without potassium oxide standard solution is blank solution.
According to instrument working conditions, adjust to zero with blank solution, and measure the emission intensity of potassium spectrum line of potassium oxide standard comparison solution series in oxidizing flame respectively. With the concentration of potassium oxide as the horizontal axis and the corresponding emission intensity of potassium oxide as the vertical axis, draw the working line 8.5. Expression of analysis of the nest
The potassium oxide content (X) of tea expressed in mass percentage is calculated according to formula (3): X,
c×100×10~6
m. ×
Wherein: C—the concentration of potassium oxide in the final test solution obtained from the working curve according to the measured emission intensity of potassium oxide, μg/mL;
mo—the mass of the sample (5.3), g.
8.6 Allowable difference
The absolute value of the difference between two parallel determination results should not be greater than 0.07%. 9 Determination of total molybdenum content Thiocyanate spectrophotometric method 9.1 Method summary
In an acidic medium, hexavalent molybdenum is reduced to pentavalent molybdenum with ascorbic acid, which forms a blood-red complex with thiocyanate. The molybdenum is determined by spectrophotometry and quantified by the working curve method. Trivalent iron and thiocyanate form a blood-red complex. After adding a reducing agent, the trivalent iron is reduced to divalent iron, which does not affect the determination. The presence of a certain amount of iron can make the color development complete quickly and help keep molybdenum in a pentavalent state. 9.2 Reagents and materials
9.2.1 Phosphoric acid (GB/T1282);
9.2.2 Aqua regia: Mix 1 volume of phosphoric acid (GB/T626) and 3 volumes of acetic acid (GB/T622). 9.2.3 Sulfuric acid (GB/T625) solution: 1+1; 9.2.4 Sulfuric acid (GB/T625) solution: 1+100; 9.2.5 Ammonium ferric sulfate (GB/T1279) solution: 5g/L; each liter of solution contains 40mL phosphoric acid (9.2.1) and 80mL sulfuric acid (9,2.3).
9.2.6 Sulfuric acid (GB/T625) solution: 1+3; 9.2.7 Ammonium thiocyanate (GB/T660) solution: 100g/L; 9.2.8 Ascorbic acid solution: 50g/L: Prepare immediately before use 9.2.9 Standard solution of zinc trioxide (1mL solution contains 50\μgMo0,). 4
HG / T 2693 95
. Weigh 0.0500g of trioxide group burned to constant weight at 500-520℃, place in a 130mL beaker, add 10mL of yu acid solution (9.2.3), heat and evaporate in a fume hood until sulfuric acid smoke appears and keep for 5 minutes, remove the beaker and cool. Add a small amount of water to dissolve the salt, transfer to a 1000mL volumetric flask, dilute with water to the mark, and shake. Weigh 0.0613g of ammonium molybdate (NHMo,O·4H20) (GB/T657), dissolve in water, weigh into a 1000mL volumetric flask, dilute to the mark, and shake well. 9.3 Instrument
Spectrophotometer.
9.4 Analysis steps
9, 4.1 Decomposition of the sample: Weigh 0.25g of the sample (accurate to 0.0001g) and place it in a 250mL beaker. Place the beaker in a fume hood. Add 20mL of aqua regia (9.2.2) and 10mL of phosphoric acid (9.2.1). Heat to dissolve. Add 20mL of sulfuric acid solution (9.2.3). Evaporate until sulfuric acid smoke appears for 5 minutes. Remove the beaker, cool it, add 50mL of hot water to dissolve the salts, filter it with medium-speed filter paper at 250 mL volumetric flask, wash the beaker and filter paper 5 to 7 times with hot sulfuric acid solution (9.2.4), cool to room temperature, dilute with water to the scale, and shake according to the hook.
Color development: aspirate 5±0.03mL of the test solution and place it in a 50mlL. volumetric flask, add 12.0mL of sulfuric acid solution (9.2.6) and 10.0mL of ascorbic acid solution (9.2.B), shake the hook each time a reagent is added, and finally dilute with water to the scale, shake, and let it stand for 20 min.
Photometric measurement: Use the blank solution as the reference solution and measure the absorbance on a spectrophotometer at a wavelength of 470nm using the absorption cell shown in Table 1.
Energizing agent
9.4.2 Drawing of working curve
Aluminum oxide standard solution
2. 00, 4. 00, 6. 00, 8. 00
1. 00, 2. 00, 3. 00, 4. 00
0. 50, 1. 00, 1. 50, 2. 00
Absorption cell
Preparation of blank solution: In a 50mL volumetric flask, add 5.0mL of ammonium ferric sulfate solution (9.2.5), 12.0mL of sulfuric acid solution (9.2.6), 100mL of ammonium thiocyanate solution (9.2.7) and 10.0mL of ascorbic acid solution (9.2.8). Each time a reagent is added, it must be weighed. Finally, dilute to the scale with water, shake well, and let stand for 20 min. Preparation of standard colorimetric solution series: According to the product model, take the sodium trioxide standard solution (9.2.9) shown in Table 1 and place it in several 50mL volumetric flasks. Add 5.0mL of ammonium ferric sulfate solution (9.2.5) to each flask. The subsequent steps are carried out according to the preparation of blank solution.
Absorbance measurement is carried out according to 9.4.1.
Use the concentration of molybdenum trioxide in the standard colorimetric solution series (\name/L) as the horizontal axis and the corresponding absorbance as the vertical axis to draw the working line
9.5 Expression of analysis results
Calculate the total aluminum content (X) in the molybdenum trioxide mass percentage table according to formula (4): HG/T 2693 --- 95
C, × 50 × 10 \6
Wherein: c is the concentration of molybdenum trioxide in the measured solution obtained from the working curve by the measured absorbance, g/mL; m is the mass of the sample, g.
9.6' Allowable error
The absolute difference between two parallel determination results should not be greater than 0.1%. 10 Determination of trace sulfur content Methylene blue spectrophotometry (arbitration method) according to ZB/T G75001 Method 1 Determination,
11 Determination of trace vegetable content Iodine titration
11.1 Method Summary
The sample is burned at 1250-1300℃ in a carbon furnace with appropriate volume flow of oxygen. All valence states of sulfur are converted into sulfur dioxide gas, which is introduced into starch aqueous solution and absorbed by water to form sulfurous acid. It is titrated with iodine standard titration solution. 11.2 Reagents and Materials
11.2.1 Iodine (GB/T675) standard titration solution: c(1/21)=0.01000mol/L. Prepared according to GB/T601, 11.2.2 Starch indicator solution: 10 g/L, prepared according to GB/T 603. Valid for 2 weeks, 11.3 Instruments and Equipment
The sulfur measuring device is shown in Figure 1. The volume consists of the following three parts: oxygen cylinder, pressure reducing valve, flow plate;
b. .Horizontal tubular high-temperature carbon determination furnace;
Gas absorber (d=30m) and 10mL brown acid burette (in accordance with the technical requirements of Class A in JJG196) Figure 1 Schematic diagram of sulfur measurement device
1- oxygen cylinder; 2- pressure valve, flowmeter 3- horizontal tubular high-temperature carbon determination furnace; 4- gas collector: 5- titration arm 11.4 Analysis steps
11.4.1 Clean the porcelain tube and test for oxygen leakage. 11.4.2 Turn on the power to gradually heat the furnace.
11.4.3 When the sulfur content in the sample is 0.005%~0.010%, weigh 1 sample; when the sulfur content is >0.010%~0.10%, weigh 0.5 g of sample (accurate to 0.000 1 g). Place in a porcelain boat that has been calcined at 1 000 ~ 1 300 °C. If the catalyst is produced by the acid method, the porcelain boat with the sample should be placed in a high-temperature furnace and calcined at 500 °C for 1 h. 6
HG / T 2693 -- 95
11.4.4 Determine the color of the titration end point: When the furnace temperature rises to about 1100 °C, add 25 mL of water, 1 mL of starch indicator solution (11.2.2) and 1~2 drops of iodine standard titration solution (11.2.1) into the gas absorber. Introduce oxygen and control the volume flow rate to 0.4~0.6Lmin. When the blue color disappears, add iodine standard at any time to make the solution always maintain a certain light blue color. If the blue color does not change after 1min, it is the end color. Stop writing. 11.4.5 When the furnace temperature rises to 1250~1300, see the end color clearly, put the porcelain boat containing the sample into the highest temperature of the furnace, plug the inlet of the test tube, and introduce oxygen. The subsequent steps are the same as 11.4.4. Make sure that the color of the solution in the gas absorber always remains at the original titration endpoint color (t1.4.4) until the blue color remains unchanged after 1 minute. 11.4.6 Turn off the power supply, stop the oxygen, and take out the porcelain boat. 11.5 Expression of analysis results
The total sulfur content (X) expressed as sulfur mass percentage is calculated according to formula (5): x,
Y, × 0.01000 × 0.016
Where: V is the volume of the iodine standard solution, mL: m, the mass of the sample, g;
0.016-1.00 mL iodine standard titration solution [c (volume.
11.6 allowance
x 100-
I) = 1.000 mol/L) The absolute difference between the results of two parallel determinations of the equivalent sulfur content expressed in grams shall not be greater than the allowable difference listed in Table 2. Table 2
Alkali content
0.005~0.010
>0.010~0.030
>0,030~0,060
>0.060~0.100
12 Determination of constant sulfur content Sulfuric acid gravimetric method (arbitration method) 12.1 Summary of the method
The test shall be carried out by semi-melting sodium carbonate and zinc oxide to convert all sulfur into free sulfate and determining it by the acid gravimetric method 12.2 Reagents and materials
12.2.1 Glacial acid (GB/T 676):
12.2.2 Formaldehyde solution (GB/T 685):%
12.2.3 Sodium carbonate-zinc oxide mixed flux: Mix 3 parts of anhydrous sodium carbonate (GB/T639) with 2 parts of zinc oxide (GB/T1280), grind and use. 12.2.4 Sodium carbonate (GB/T639) solution: 20g/L; 12.2,5 Barium acetate solution: 100g/L; Weigh 123.5g barium hydroxide [Ba(OH)2·8H2O) (GB/T630), dissolve in 500mL water, add 45mL glacial acid (GB/T676), and cool. Dilute to 1000mL with water, stir, 12.2,6 Acetic acid (GB/T 676) solution: 1+100,12,3 Analysis steps
HG/T2693—95
When the sulfate content in the sample is higher than 3.0%. Weigh 0.5% of the sample: When the sulfate content is less than or equal to 3.0%, weigh 1g of the sample (accurate to 0.0001g) and put it in a 25mL porcelain crucible, add 5-8g of mixed flux (12.2.3), stir, and then add 1-2g of mixed flux (12.2.3) on top. Put the crucible into a high-flow furnace, open the furnace door slightly, gradually increase the temperature, and maintain it at 750-800℃ for 1-15h. Take it out and cool it. Use 100-150mL hot water to wash the sintered material into a 300mL beaker. Use a glass rod to break the sintered material, boil it for 5min, and filter it into a 400mL beaker by decanting. Use hot sodium carbonate solution (12.2.4) to wash the precipitate and the beaker 8-10 times (if the filtrate appears turbid, it is because the alkalinity decreases and zinc hydroxide precipitates. When the solution is acidified, it will dissolve and will not affect the determination). The filtrate is simmered to about 70 mL, and 30 mL of glacial acetic acid (12.2.1) and 30 mL of formaldehyde solution (12.2.2) are slowly added in a ventilated chamber. Boil for 15-20 min until the chromium is completely reduced and becomes bright green. Dilute with water to 200-250 mL and heat to boiling. Slowly add 10 mL of barium acetate solution (12.2.5). Leave in a warm place for 4 h or overnight. Filter with slow fixed filter paper, wash with acetic acid solution (12.2.6) 6-8 times, place the filter paper in garbage, carbonize it with a low fire, place it in a high-temperature furnace, burn it at 800-850℃ for 30 min, take it out and place it in a desiccator to cool to room temperature and weigh it. 12.4 Expression of analytical results
The constant sulfur content (X) expressed as a percentage of sulfate radical mass is calculated according to formula (6): x.
(m,-m, )x0.4115
Where: m. The mass of the empty crucible, gi
m,—The mass of the glass plus precipitate, g:
The mass of the sample, g
0.4115-—The coefficient for converting sulfuric acid to sulfate 12.5 Allowable difference
The absolute value of the difference between two parallel determination results shall comply with the requirements of Table 3, Table 3
Sulfate content
>1.0~3. 0
13 Determination of constant sulfate content Pan weight method × 100
Allowable difference
This method is applicable to samples dissolved in hydrochloric acid, but not to samples containing steel and concentrate. This method adopts ZB/TG75001 Method 2. Weighing sample: When the sulfate content in the sample is higher than 3.0%, weigh 0.5g sample; when the sulfate content is between 1.0% and 3.0%, weigh 1g sample; when the sulfate content is lower than 1.0%, weigh 2g sample (accuracy 0.0001). The allowable difference shall comply with the provisions of Table 3 in 12.5 of this standard. 14 Determination of burning distortion quantitative method
Adopt the method specified in ZB/TG75003, true
Additional instructions:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation. This standard was drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation, and the main initiator of this standard is Huang Songsheng. Lv Shuanyou. As of the date of implementation of this standard, the former Ministry of Chemical Industry of the People's Republic of China Standard HG1-1427-81 "Method for Chemical Composition Analysis of Medium Temperature Shift Catalyst" shall be invalidated.
Additional Notes:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation, and this standard is drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation. The main drafters of this standard are Huang Songsheng and Lv Shuanyou. ...1 Iodine (GB/T675) standard titration solution: c(1/21)=0.01000mol/L. Prepared according to GB/T601, 11.2.2 Starch indicator solution: 10 g/L, prepared according to GB/T 603. Valid for 2 weeks, 11.3 Instruments and equipment
The sulfur measuring device is shown in Figure 1. The loading volume consists of the following three parts: oxygen cylinder, pressure reducing valve, flow plate;
b. .Horizontal tubular high-temperature carbon determination furnace;
Gas absorber (d=30m) and 10mL brown acid burette (in accordance with the technical requirements of Class A in JJG196) Figure 1 Schematic diagram of sulfur measurement device
1- oxygen cylinder; 2- pressure valve, flowmeter 3- horizontal tubular high-temperature carbon determination furnace; 4- gas collector: 5- titration arm 11.4 Analysis steps
11.4.1 Clean the porcelain tube and test for oxygen leakage. 11.4.2 Turn on the power to gradually heat the furnace.
11.4.3 When the sulfur content in the sample is 0.005%~0.010%, weigh 1 sample; when the sulfur content is >0.010%~0.10%, weigh 0.5 g of sample (accurate to 0.000 1 g). Place in a porcelain boat that has been calcined at 1 000 ~ 1 300 °C. If the catalyst is produced by the acid method, the porcelain boat with the sample should be placed in a high-temperature furnace and calcined at 500 °C for 1 h. 6
HG / T 2693 -- 95
11.4.4 Determine the color of the titration end point: When the furnace temperature rises to about 1100 °C, add 25 mL of water, 1 mL of starch indicator solution (11.2.2) and 1~2 drops of iodine standard titration solution (11.2.1) into the gas absorber. Introduce oxygen and control the volume flow rate to 0.4~0.6Lmin. When the blue color disappears, add iodine standard at any time to make the solution always maintain a certain light blue color. If the blue color does not change after 1min, it is the end color. Stop writing. 11.4.5 When the furnace temperature rises to 1250~1300, see the end color clearly, put the porcelain boat containing the sample into the highest temperature of the furnace, plug the inlet of the test tube, and introduce oxygen. The subsequent steps are the same as 11.4.4. Make sure that the color of the solution in the gas absorber always remains at the original titration endpoint color (t1.4.4) until the blue color remains unchanged after 1 minute. 11.4.6 Turn off the power supply, stop the oxygen, and take out the porcelain boat. 11.5 Expression of analysis results
The total sulfur content (X) expressed as sulfur mass percentage is calculated according to formula (5): x,
Y, × 0.01000 × 0.016
Where: V is the volume of the iodine standard solution, mL: m, the mass of the sample, g;
0.016-1.00 mL iodine standard titration solution [c (volume.
11.6 allowance
x 100-
I) = 1.000 mol/L) The absolute difference between the results of two parallel determinations of the equivalent sulfur content expressed in grams shall not be greater than the allowable difference listed in Table 2. Table 2
Alkali content
0.005~0.010
>0.010~0.030
>0.030~0.060
>0.060~0.100
12 Determination of constant sulfur content Sulfuric acid gravimetric method (arbitration method) 12.1 Summary of the method
The test shall be carried out by semi-melting sodium carbonate and zinc oxide to convert all sulfur into free sulfate and determining it by the acid gravimetric method 12.2 Reagents and materials
12.2.1 Glacial acid (GB/T 676):
12.2.2 Formaldehyde solution (GB/T 685):%
12.2.3 Sodium carbonate-zinc oxide mixed flux: Mix 3 parts of anhydrous sodium carbonate (GB/T639) with 2 parts of zinc oxide (GB/T1280), grind and use. 12.2.4 Sodium carbonate (GB/T639) solution: 20g/L; 12.2,5 Barium acetate solution: 100g/L; Weigh 123.5g barium hydroxide [Ba(OH)2·8H2O) (GB/T630), dissolve in 500mL water, add 45mL glacial acid (GB/T676), and cool. Dilute to 1000mL with water, stir, 12.2,6 Acetic acid (GB/T 676) solution: 1+100,12,3 Analysis steps
HG/T2693—95
When the sulfate content in the sample is higher than 3.0%. Weigh 0.5% of the sample: When the sulfate content is less than or equal to 3.0%, weigh 1g of the sample (accurate to 0.0001g) and put it in a 25mL porcelain crucible, add 5-8g of mixed flux (12.2.3), stir, and then add 1-2g of mixed flux (12.2.3) on top. Put the crucible into a high-flow furnace, open the furnace door slightly, gradually increase the temperature, and maintain it at 750-800℃ for 1-15h. Take it out and cool it. Use 100-150mL hot water to wash the sintered material into a 300mL beaker. Use a glass rod to break the sintered material, boil it for 5min, and filter it into a 400mL beaker by decanting. Use hot sodium carbonate solution (12.2.4) to wash the precipitate and the beaker 8-10 times (if the filtrate appears turbid, it is because the alkalinity decreases and zinc hydroxide precipitates. When the solution is acidified, it will dissolve and will not affect the determination). The filtrate is simmered to about 70 mL, and 30 mL of glacial acetic acid (12.2.1) and 30 mL of formaldehyde solution (12.2.2) are slowly added in a ventilated chamber. Boil for 15-20 min until the chromium is completely reduced and becomes bright green. Dilute with water to 200-250 mL and heat to boiling. Slowly add 10 mL of barium acetate solution (12.2.5). Leave in a warm place for 4 h or overnight. Filter with slow fixed filter paper, wash with acetic acid solution (12.2.6) 6-8 times, place the filter paper in garbage, carbonize it with a low fire, place it in a high-temperature furnace, burn it at 800-850℃ for 30 min, take it out and place it in a desiccator to cool to room temperature and weigh it. 12.4 Expression of analytical results
The constant sulfur content (X) expressed as a percentage of sulfate radical mass is calculated according to formula (6): x.
(m,-m, )x0.4115
Where: m. The mass of the empty crucible, gi
m,—The mass of the glass plus precipitate, g:
The mass of the sample, g
0.4115-—The coefficient for converting sulfuric acid to sulfate 12.5 Allowable difference
The absolute value of the difference between two parallel determination results shall comply with the requirements of Table 3, Table 3
Sulfate content
>1.0~3. 0
13 Determination of constant sulfate content Pan weight method × 100
Allowable difference
This method is applicable to samples dissolved in hydrochloric acid, but not to samples containing steel and concentrate. This method adopts ZB/TG75001 Method 2. Weighing sample: When the sulfate content in the sample is higher than 3.0%, weigh 0.5g sample; when the sulfate content is between 1.0% and 3.0%, weigh 1g sample; when the sulfate content is lower than 1.0%, weigh 2g sample (accuracy 0.0001). The allowable difference shall comply with the provisions of Table 3 in 12.5 of this standard. 14 Determination of burning distortion quantitative method
Adopt the method specified in ZB/TG75003, true
Additional instructions:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation. This standard was drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation, and the main initiator of this standard is Huang Songsheng. Lv Shuanyou. As of the date of implementation of this standard, the former Ministry of Chemical Industry of the People's Republic of China Standard HG1-1427-81 "Method for Chemical Composition Analysis of Medium Temperature Shift Catalyst" shall be invalidated.
Additional Notes:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation, and this standard is drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation. The main drafters of this standard are Huang Songsheng and Lv Shuanyou. ...1 Iodine (GB/T675) standard titration solution: c(1/21)=0.01000mol/L. Prepared according to GB/T601, 11.2.2 Starch indicator solution: 10 g/L, prepared according to GB/T 603. Valid for 2 weeks, 11.3 Instruments and equipment
The sulfur measuring device is shown in Figure 1. The loading volume consists of the following three parts: oxygen cylinder, pressure reducing valve, flow plate;
b. .Horizontal tubular high-temperature carbon determination furnace;
Gas absorber (d=30m) and 10mL brown acid burette (in accordance with the technical requirements of Class A in JJG196) Figure 1 Schematic diagram of sulfur measurement device
1- oxygen cylinder; 2- pressure valve, flowmeter 3- horizontal tubular high-temperature carbon determination furnace; 4- gas collector: 5- titration arm 11.4 Analysis steps
11.4.1 Clean the porcelain tube and test for oxygen leakage. 11.4.2 Turn on the power to gradually heat the furnace.
11.4.3 When the sulfur content in the sample is 0.005%~0.010%, weigh 1 sample; when the sulfur content is >0.010%~0.10%, weigh 0.5 g of sample (accurate to 0.000 1 g). Place in a porcelain boat that has been calcined at 1 000 ~ 1 300 °C. If the catalyst is produced by the acid method, the porcelain boat with the sample should be placed in a high-temperature furnace and calcined at 500 °C for 1 h. 6
HG / T 2693 -- 95
11.4.4 Determine the color of the titration end point: When the furnace temperature rises to about 1100 °C, add 25 mL of water, 1 mL of starch indicator solution (11.2.2) and 1~2 drops of iodine standard titration solution (11.2.1) into the gas absorber. Introduce oxygen and control the volume flow rate to 0.4~0.6Lmin. When the blue color disappears, add iodine standard at any time to make the solution always maintain a certain light blue color. If the blue color does not change after 1min, it is the end color. Stop writing. 11.4.5 When the furnace temperature rises to 1250~1300, see the end color clearly, put the porcelain boat containing the sample into the highest temperature of the furnace, plug the inlet of the test tube, and introduce oxygen. The subsequent steps are the same as 11.4.4. Make sure that the color of the solution in the gas absorber always remains at the original titration endpoint color (t1.4.4) until the blue color remains unchanged after 1 minute. 11.4.6 Turn off the power supply, stop the oxygen, and take out the porcelain boat. 11.5 Expression of analysis results
The total sulfur content (X) expressed as sulfur mass percentage is calculated according to formula (5): x,
Y, × 0.01000 × 0.016
Where: V is the volume of the iodine standard solution, mL: m, the mass of the sample, g;
0.016-1.00 mL iodine standard titration solution [c (volume.
11.6 allowance
x 100-
I) = 1.000 mol/L) The absolute difference between the results of two parallel determinations of the equivalent sulfur content expressed in grams shall not be greater than the allowable difference listed in Table 2. Table 2
Alkali content
0.005~0.010
>0.010~0.030
>0.030~0.060
>0.060~0.100
12 Determination of constant sulfur content Sulfuric acid gravimetric method (arbitration method) 12.1 Summary of the method
The test shall be carried out by semi-melting sodium carbonate and zinc oxide to convert all sulfur into free sulfate and determining it by the acid gravimetric method 12.2 Reagents and materials
12.2.1 Glacial acid (GB/T 676):
12.2.2 Formaldehyde solution (GB/T 685):%
12.2.3 Sodium carbonate-zinc oxide mixed flux: Mix 3 parts of anhydrous sodium carbonate (GB/T639) with 2 parts of zinc oxide (GB/T1280), grind and use. 12.2.4 Sodium carbonate (GB/T639) solution: 20g/L; 12.2,5 Barium acetate solution: 100g/L; Weigh 123.5g barium hydroxide [Ba(OH)2·8H2O) (GB/T630), dissolve in 500mL water, add 45mL glacial acid (GB/T676), and cool. Dilute to 1000mL with water, stir, 12.2,6 Acetic acid (GB/T 676) solution: 1+100,12,3 Analysis steps
HG/T2693—95
When the sulfate content in the sample is higher than 3.0%. Weigh 0.5% of the sample: When the sulfate content is less than or equal to 3.0%, weigh 1g of the sample (accurate to 0.0001g) and put it in a 25mL porcelain crucible, add 5-8g of mixed flux (12.2.3), stir, and then add 1-2g of mixed flux (12.2.3) on top. Put the crucible into a high-flow furnace, open the furnace door slightly, gradually increase the temperature, and maintain it at 750-800℃ for 1-15h. Take it out and cool it. Use 100-150mL hot water to wash the sintered material into a 300mL beaker. Use a glass rod to break the sintered material, boil it for 5min, and filter it into a 400mL beaker by decanting. Use hot sodium carbonate solution (12.2.4) to wash the precipitate and the beaker 8-10 times (if the filtrate appears turbid, it is because the alkalinity decreases and zinc hydroxide precipitates. When the solution is acidified, it will dissolve and will not affect the determination). The filtrate is simmered to about 70 mL, and 30 mL of glacial acetic acid (12.2.1) and 30 mL of formaldehyde solution (12.2.2) are slowly added in a ventilated chamber. Boil for 15-20 min until the chromium is completely reduced and becomes bright green. Dilute with water to 200-250 mL and heat to boiling. Slowly add 10 mL of barium acetate solution (12.2.5). Leave in a warm place for 4 h or overnight. Filter with slow fixed filter paper, wash with acetic acid solution (12.2.6) 6-8 times, place the filter paper in garbage, carbonize it with a low fire, place it in a high-temperature furnace, burn it at 800-850℃ for 30 min, take it out and place it in a desiccator to cool to room temperature and weigh it. 12.4 Expression of analytical results
The constant sulfur content (X) expressed as a percentage of sulfate mass is calculated according to formula (6): x.
(m,-m, )x0.4115
Where: m. The mass of the empty crucible, gi
m,—The mass of the glass plus precipitate, g:
The mass of the sample, g
0.4115-—The coefficient for converting sulfuric acid to sulfate 12.5 Allowable difference
The absolute value of the difference between two parallel determination results shall comply with the requirements of Table 3, Table 3
Sulfate content
>1.0~3. 0
13 Determination of constant sulfate content Pan weight method × 100
Allowable difference
This method is applicable to samples dissolved in hydrochloric acid, but not to samples containing steel and concentrate. This method adopts ZB/TG75001 Method 2. Weighing sample: When the sulfate content in the sample is higher than 3.0%, weigh 0.5g of sample; when the sulfate content is between 1.0% and 3.0%, weigh 1g of sample; when the sulfate content is lower than 1.0%, weigh 2g of sample (accuracy 0.0001). The allowable difference shall comply with the provisions of Table 3 in 12.5 of this standard. 14 Determination of burning distortion quantitative method
Adopt the method specified in ZB/TG75003, true
Additional instructions:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation. This standard was drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation, and the main initiator of this standard is Huang Songsheng. Lv Shuanyou. As of the date of implementation of this standard, the former Ministry of Chemical Industry of the People's Republic of China Standard HG1-1427-81 "Method for Chemical Composition Analysis of Medium Temperature Shift Catalyst" shall be invalidated.
Additional Notes:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation, and this standard is drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation. The main drafters of this standard are Huang Songsheng and Lv Shuanyou. ...3 Instruments and equipment
The sulfur measuring device is shown in Figure 1. It consists of the following three parts: oxygen cylinder, pressure reducing valve, flow meter;
b. Horizontal tubular high-temperature carbon determination furnace;
Gas absorber (d=30m) and 10mL brown acid burette (in accordance with the technical requirements of Class A in JJG196) Figure 1 Schematic diagram of sulfur measuring device
1-Oxygen cylinder; 2-Pressure reducing valve, flow meter 3-Horizontal tubular high-temperature carbon determination furnace; 4-Gas collector: 5-Titration arm 11.4 Analysis steps
11.4.1 Clean the porcelain tube and test for oxygen leakage. 11.4.2 Turn on the power to gradually heat up the furnace.
11.4.3 When the sulfur content in the sample is 0.005%~0.010%, weigh 1 sample; when the sulfur content is >0.010%~0.10%, weigh 0.5 g of the sample (accurate to 0.0001 g). Place it in a porcelain boat that has been calcined at 1 000~1 300°C. If the catalyst is produced by the acid method, the porcelain boat with the sample should be placed in a high-temperature furnace and calcined at 500°C for 1 hour. 6
HG / T 2693 -- 95
11.4.4 Determine the color of the titration end point: When the furnace temperature rises to about 1100°C, add 25 mL of water, 1 mL of starch indicator solution (11.2.2) and 1~2 drops of iodine standard titration solution (11.2.1) into the gas absorber. Introduce oxygen and control the volume flow rate to 0.4~0.6Lmin. When the blue color disappears, add iodine standard at any time to make the solution always maintain a certain light blue color. If the blue color does not change after 1min, it is the end color. Stop writing. 11.4.5 When the furnace temperature rises to 1250~1300, see the end color clearly, put the porcelain boat containing the sample into the highest temperature of the furnace, plug the inlet of the test tube, and introduce oxygen. The subsequent steps are the same as 11.4.4. Make sure that the color of the solution in the gas absorber always remains at the original titration endpoint color (t1.4.4) until the blue color remains unchanged after 1 minute. 11.4.6 Turn off the power supply, stop the oxygen, and take out the porcelain boat. 11.5 Expression of analysis results
The total sulfur content (X) expressed as sulfur mass percentage is calculated according to formula (5): x,
Y, × 0.01000 × 0.016
Where: V is the volume of the iodine standard solution, mL:m, the mass of the sample, g;
0.016-1.00 mL iodine standard titration solution [c (volume. www.bzxz.net
11.6 allowance
x 100-
I) = 1.000 mol/L) The absolute difference between the results of two parallel determinations of the equivalent sulfur content expressed in grams shall not be greater than the allowable difference listed in Table 2. Table 2
Alkali content
0.005~0.010
>0.010~0.030
>0,030~0,060
>0.060~0.100
12 Determination of constant sulfur content Sulfuric acid gravimetric method (arbitration method) 12.1 Summary of the method
The test shall be carried out by semi-melting sodium carbonate and zinc oxide to convert all sulfur into free sulfate and determining it by the acid gravimetric method 12.2 Reagents and materials
12.2.1 Glacial acid (GB/T 676):
12.2.2 Formaldehyde solution (GB/T 685):%
12.2.3 Sodium carbonate-zinc oxide mixed flux: Mix 3 parts of anhydrous sodium carbonate (GB/T639) with 2 parts of zinc oxide (GB/T1280), grind and use. 12.2.4 Sodium carbonate (GB/T639) solution: 20g/L; 12.2,5 Barium acetate solution: 100g/L; Weigh 123.5g barium hydroxide [Ba(OH)2·8H2O) (GB/T630), dissolve in 500mL water, add 45mL glacial acid (GB/T676), and cool. Dilute to 1000mL with water, stir, 12.2,6 Acetic acid (GB/T 676) solution: 1+100,12,3 Analysis steps
HG/T2693—95
When the sulfate content in the sample is higher than 3.0%. Weigh 0.5% of the sample: When the sulfate content is less than or equal to 3.0%, weigh 1g of the sample (accurate to 0.0001g) and put it in a 25mL porcelain crucible, add 5-8g of mixed flux (12.2.3), stir, and then add 1-2g of mixed flux (12.2.3) on top. Put the crucible into a high-flow furnace, open the furnace door slightly, gradually increase the temperature, and maintain it at 750-800℃ for 1-15h. Take it out and cool it. Use 100-150mL hot water to wash the sintered material into a 300mL beaker. Use a glass rod to break the sintered material, boil it for 5min, and filter it into a 400mL beaker by decanting. Use hot sodium carbonate solution (12.2.4) to wash the precipitate and the beaker 8-10 times (if the filtrate appears turbid, it is because the alkalinity decreases and zinc hydroxide precipitates. When the solution is acidified, it will dissolve and will not affect the determination). The filtrate is simmered to about 70 mL, and 30 mL of glacial acetic acid (12.2.1) and 30 mL of formaldehyde solution (12.2.2) are slowly added in a ventilated chamber. Boil for 15-20 min until the chromium is completely reduced and becomes bright green. Dilute with water to 200-250 mL and heat to boiling. Slowly add 10 mL of barium acetate solution (12.2.5). Leave in a warm place for 4 h or overnight. Filter with slow fixed filter paper, wash with acetic acid solution (12.2.6) 6-8 times, place the filter paper in garbage, carbonize it with a low fire, place it in a high-temperature furnace, burn it at 800-850℃ for 30 min, take it out and place it in a desiccator to cool to room temperature and weigh it. 12.4 Expression of analytical results
The constant sulfur content (X) expressed as a percentage of sulfate radical mass is calculated according to formula (6): x.
(m,-m, )x0.4115
Where: m. The mass of the empty crucible, gi
m,—The mass of the glass plus precipitate, g:
The mass of the sample, g
0.4115-—The coefficient for converting sulfuric acid to sulfate 12.5 Allowable difference
The absolute value of the difference between two parallel determination results shall comply with the requirements of Table 3, Table 3
Sulfate content
>1.0~3. 0
13 Determination of constant sulfate content Pan weight method × 100
Allowable difference
This method is applicable to samples dissolved in hydrochloric acid, but not to samples containing steel and concentrate. This method adopts ZB/TG75001 Method 2. Weighing sample: When the sulfate content in the sample is higher than 3.0%, weigh 0.5g sample; when the sulfate content is between 1.0% and 3.0%, weigh 1g sample; when the sulfate content is lower than 1.0%, weigh 2g sample (accuracy 0.0001). The allowable difference shall comply with the provisions of Table 3 in 12.5 of this standard. 14 Determination of burning distortion quantitative method
Adopt the method specified in ZB/TG75003, true
Additional instructions:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation. This standard was drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation, and the main initiator of this standard is Huang Songsheng. Lv Shuanyou. As of the date of implementation of this standard, the former Ministry of Chemical Industry of the People's Republic of China Standard HG1-1427-81 "Method for Chemical Composition Analysis of Medium Temperature Shift Catalyst" shall be invalidated.
Additional Notes:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation, and this standard is drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation. The main drafters of this standard are Huang Songsheng and Lv Shuanyou. ...3 Instruments and equipment
The sulfur measuring device is shown in Figure 1. It consists of the following three parts: oxygen cylinder, pressure reducing valve, flow meter;
b. Horizontal tubular high-temperature carbon determination furnace;
Gas absorber (d=30m) and 10mL brown acid burette (in accordance with the technical requirements of Class A in JJG196) Figure 1 Schematic diagram of sulfur measuring device
1-Oxygen cylinder; 2-Pressure reducing valve, flow meter 3-Horizontal tubular high-temperature carbon determination furnace; 4-Gas collector: 5-Titration arm 11.4 Analysis steps
11.4.1 Clean the porcelain tube and test for oxygen leakage. 11.4.2 Turn on the power to gradually heat up the furnace.
11.4.3 When the sulfur content in the sample is 0.005%~0.010%, weigh 1 sample; when the sulfur content is >0.010%~0.10%, weigh 0.5 g of the sample (accurate to 0.0001 g). Place it in a porcelain boat that has been calcined at 1 000~1 300°C. If the catalyst is produced by the acid method, the porcelain boat with the sample should be placed in a high-temperature furnace and calcined at 500°C for 1 hour. 6
HG / T 2693 -- 95
11.4.4 Determine the color of the titration end point: When the furnace temperature rises to about 1100°C, add 25 mL of water, 1 mL of starch indicator solution (11.2.2) and 1~2 drops of iodine standard titration solution (11.2.1) into the gas absorber. Introduce oxygen and control the volume flow rate to 0.4~0.6Lmin. When the blue color disappears, add iodine standard at any time to make the solution always maintain a certain light blue color. If the blue color does not change after 1min, it is the end color. Stop writing. 11.4.5 When the furnace temperature rises to 1250~1300, see the end color clearly, put the porcelain boat containing the sample into the highest temperature of the furnace, plug the inlet of the test tube, and introduce oxygen. The subsequent steps are the same as 11.4.4. Make sure that the color of the solution in the gas absorber always remains at the original titration endpoint color (t1.4.4) until the blue color remains unchanged after 1 minute. 11.4.6 Turn off the power supply, stop the oxygen, and take out the porcelain boat. 11.5 Expression of analysis results
The total sulfur content (X) expressed as sulfur mass percentage is calculated according to formula (5): x,
Y, × 0.01000 × 0.016
Where: V is the volume of the iodine standard solution, mL: m, the mass of the sample, g;
0.016-1.00 mL iodine standard titration solution [c (volume.
11.6 allowance
x 100-
I) = 1.000 mol/L) The absolute difference between the results of two parallel determinations of the equivalent sulfur content expressed in grams shall not be greater than the allowable difference listed in Table 2. Table 2
Alkali content
0.005~0.010
>0.010~0.030
>0,030~0,060
>0.060~0.100
12 Determination of constant sulfur content Sulfuric acid gravimetric method (arbitration method) 12.1 Summary of the method
The test shall be carried out by semi-melting sodium carbonate and zinc oxide to convert all sulfur into free sulfate and determining it by the acid gravimetric method 12.2 Reagents and materials
12.2.1 Glacial acid (GB/T 676):
12.2.2 Formaldehyde solution (GB/T 685):%
12.2.3 Sodium carbonate-zinc oxide mixed flux: Mix 3 parts of anhydrous sodium carbonate (GB/T639) with 2 parts of zinc oxide (GB/T1280), grind and use. 12.2.4 Sodium carbonate (GB/T639) solution: 20g/L; 12.2,5 Barium acetate solution: 100g/L; Weigh 123.5g barium hydroxide [Ba(OH)2·8H2O) (GB/T630), dissolve in 500mL water, add 45mL glacial acid (GB/T676), and cool. Dilute to 1000mL with water, stir, 12.2,6 Acetic acid (GB/T 676) solution: 1+100,12,3 Analysis steps
HG/T2693—95
When the sulfate content in the sample is higher than 3.0%. Weigh 0.5% of the sample: When the sulfate content is less than or equal to 3.0%, weigh 1g of the sample (accurate to 0.0001g) and put it in a 25mL porcelain crucible, add 5-8g of mixed flux (12.2.3), stir, and then add 1-2g of mixed flux (12.2.3) on top. Put the crucible into a high-flow furnace, open the furnace door slightly, gradually increase the temperature, and maintain it at 750-800℃ for 1-15h. Take it out and cool it. Use 100-150mL hot water to wash the sintered material into a 300mL beaker. Use a glass rod to break the sintered material, boil it for 5min, and filter it into a 400mL beaker by decanting. Use hot sodium carbonate solution (12.2.4) to wash the precipitate and the beaker 8-10 times (if the filtrate appears turbid, it is because the alkalinity decreases and zinc hydroxide precipitates. When the solution is acidified, it will dissolve and will not affect the determination). The filtrate is simmered to about 70 mL, and 30 mL of glacial acetic acid (12.2.1) and 30 mL of formaldehyde solution (12.2.2) are slowly added in a ventilated chamber. Boil for 15-20 min until the chromium is completely reduced and becomes bright green. Dilute with water to 200-250 mL and heat to boiling. Slowly add 10 mL of barium acetate solution (12.2.5). Leave in a warm place for 4 h or overnight. Filter with slow fixed filter paper, wash with acetic acid solution (12.2.6) 6-8 times, place the filter paper in garbage, carbonize it with a low fire, place it in a high-temperature furnace, burn it at 800-850℃ for 30 min, take it out and place it in a desiccator to cool to room temperature and weigh it. 12.4 Expression of analytical results
The constant sulfur content (X) expressed as a percentage of sulfate radical mass is calculated according to formula (6): x.
(m,-m, )x0.4115
Where: m. The mass of the empty crucible, gi
m,—The mass of the glass plus precipitate, g:
The mass of the sample, g
0.4115-—The coefficient for converting sulfuric acid to sulfate 12.5 Allowable difference
The absolute value of the difference between two parallel determination results shall comply with the requirements of Table 3, Table 3
Sulfate content
>1.0~3. 0
13 Determination of constant sulfate content Pan weight method × 100
Allowable difference
This method is applicable to samples dissolved in hydrochloric acid, but not to samples containing steel and concentrate. This method adopts ZB/TG75001 Method 2. Weighing sample: When the sulfate content in the sample is higher than 3.0%, weigh 0.5g sample; when the sulfate content is between 1.0% and 3.0%, weigh 1g sample; when the sulfate content is lower than 1.0%, weigh 2g sample (accuracy 0.0001). The allowable difference shall comply with the provisions of Table 3 in 12.5 of this standard. 14 Determination of burning distortion quantitative method
Adopt the method specified in ZB/TG75003, true
Additional instructions:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation. This standard was drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation, and the main initiator of this standard is Huang Songsheng. Lv Shuanyou. As of the date of implementation of this standard, the former Ministry of Chemical Industry of the People's Republic of China Standard HG1-1427-81 "Method for Chemical Composition Analysis of Medium Temperature Shift Catalyst" shall be invalidated.
Additional Notes:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation, and this standard is drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation. The main drafters of this standard are Huang Songsheng and Lv Shuanyou. ...When the concentration of iodine is 10%, weigh 0.5 g of the sample (accurate to 0.0001 g). Place it in a porcelain boat that has been calcined at 1 000 ~ 1 300 °C. If the catalyst is produced by the acid method, the porcelain boat with the sample should be placed in a high-temperature furnace and calcined at 500 °C for 1 h. 6
HG / T 2693 -- 95
11.4.4 Determine the color of the titration end point: When the furnace temperature rises to about 1100 °C, add 25 mL of water, 1 mL of starch indicator solution (11.2.2) and 1~2 drops of iodine standard titration solution (11.2.1) into the gas absorber. Introduce oxygen and control the volume flow rate to 0.4~0.6Lmin. When the blue color disappears, add iodine standard at any time to make the solution always maintain a certain light blue color. If the blue color does not change after 1min, it is the end color. Stop writing. 11.4.5 When the furnace temperature rises to 1250~1300, see the end color clearly, put the porcelain boat containing the sample into the highest temperature of the furnace, plug the inlet of the test tube, and introduce oxygen. The subsequent steps are the same as 11.4.4. Make sure that the color of the solution in the gas absorber always remains at the original titration endpoint color (t1.4.4) until the blue color remains unchanged after 1 minute. 11.4.6 Turn off the power supply, stop the oxygen, and take out the porcelain boat. 11.5 Expression of analysis results
The total sulfur content (X) expressed as sulfur mass percentage is calculated according to formula (5): x,
Y, × 0.01000 × 0.016
Where: V is the volume of the iodine standard solution, mL: m, the mass of the sample, g;
0.016-1.00 mL iodine standard titration solution [c (volume.
11.6 allowance
x 100-
I) = 1.000 mol/L) The absolute difference between the results of two parallel determinations of the equivalent sulfur content expressed in grams shall not be greater than the allowable difference listed in Table 2. Table 2
Alkali content
0.005~0.010
>0.010~0.030
>0.030~0.060
>0.060~0.100
12 Determination of constant sulfur content Sulfuric acid gravimetric method (arbitration method) 12.1 Summary of the method
The test shall be carried out by semi-melting sodium carbonate and zinc oxide to convert all sulfur into free sulfate and determining it by the acid gravimetric method 12.2 Reagents and materials
12.2.1 Glacial acid (GB/T 676):
12.2.2 Formaldehyde solution (GB/T 685):%
12.2.3 Sodium carbonate-zinc oxide mixed flux: Mix 3 parts of anhydrous sodium carbonate (GB/T639) with 2 parts of zinc oxide (GB/T1280), grind and use. 12.2.4 Sodium carbonate (GB/T639) solution: 20g/L; 12.2,5 Barium acetate solution: 100g/L; Weigh 123.5g barium hydroxide [Ba(OH)2·8H2O) (GB/T630), dissolve in 500mL water, add 45mL glacial acid (GB/T676), and cool. Dilute to 1000mL with water, stir, 12.2,6 Acetic acid (GB/T 676) solution: 1+100,12,3 Analysis steps
HG/T2693—95
When the sulfate content in the sample is higher than 3.0%. Weigh 0.5% of the sample: When the sulfate content is less than or equal to 3.0%, weigh 1g of the sample (accurate to 0.0001g) and put it in a 25mL porcelain crucible, add 5-8g of mixed flux (12.2.3), stir, and then add 1-2g of mixed flux (12.2.3) on top. Put the crucible into a high-flow furnace, open the furnace door slightly, gradually increase the temperature, and maintain it at 750-800℃ for 1-15h. Take it out and cool it. Use 100-150mL hot water to wash the sintered material into a 300mL beaker. Use a glass rod to break the sintered material, boil it for 5min, and filter it into a 400mL beaker by decanting. Use hot sodium carbonate solution (12.2.4) to wash the precipitate and the beaker 8-10 times (if the filtrate appears turbid, it is because the alkalinity decreases and zinc hydroxide precipitates. When the solution is acidified, it will dissolve and will not affect the determination). The filtrate is simmered to about 70 mL, and 30 mL of glacial acetic acid (12.2.1) and 30 mL of formaldehyde solution (12.2.2) are slowly added in a ventilated chamber. Boil for 15-20 min until the chromium is completely reduced and becomes bright green. Dilute with water to 200-250 mL and heat to boiling. Slowly add 10 mL of barium acetate solution (12.2.5). Leave in a warm place for 4 h or overnight. Filter with slow fixed filter paper, wash with acetic acid solution (12.2.6) 6-8 times, place the filter paper in garbage, carbonize it with a low fire, place it in a high-temperature furnace, burn it at 800-850℃ for 30 min, take it out and place it in a desiccator to cool to room temperature and weigh it. 12.4 Expression of analytical results
The constant sulfur content (X) expressed as a percentage of sulfate mass is calculated according to formula (6): x.
(m,-m, )x0.4115
Where: m. The mass of the empty crucible, gi
m,—The mass of the glass plus precipitate, g:
The mass of the sample, g
0.4115-—The coefficient for converting sulfuric acid to sulfate 12.5 Allowable difference
The absolute value of the difference between two parallel determination results shall comply with the requirements of Table 3, Table 3
Sulfate content
>1.0~3. 0
13 Determination of constant sulfate content Pan weight method × 100
Allowable difference
This method is applicable to samples dissolved in hydrochloric acid, but not to samples containing steel and concentrate. This method adopts ZB/TG75001 Method 2. Weighing sample: When the sulfate content in the sample is higher than 3.0%, weigh 0.5g sample; when the sulfate content is between 1.0% and 3.0%, weigh 1g sample; when the sulfate content is lower than 1.0%, weigh 2g sample (accuracy 0.0001). The allowable difference shall comply with the provisions of Table 3 in 12.5 of this standard. 14 Determination of burning distortion quantitative method
Adopt the method specified in ZB/TG75003, true
Additional instructions:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation. This standard was drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation, and the main initiator of this standard is Huang Songsheng. Lv Shuanyou. As of the date of implementation of this standard, the former Ministry of Chemical Industry of the People's Republic of China Standard HG1-1427-81 "Method for Chemical Composition Analysis of Medium Temperature Shift Catalyst" shall be invalidated.
Additional Notes:
HG/T2693-95
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Research Institute of Nanjing Chemical Industry (Group) Corporation, and this standard is drafted by the Chemical Agent Factory of Nanjing Chemical Industry (Group) Corporation. The main drafters of this standard are Huang Songsheng and Lv Shuanyou. ...When the concentration of iodine is 10%, weigh 0.5 g of the sample (accurate to 0.0001 g). Place it in a porcelain boat that has been calcined at 1 000 ~ 1 300 °C. If the catalyst is produced by the acid method, the porcelain boat with the sa
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