GB/T 3884.3-2000 Chemical analysis methods for copper concentrates - Determination of sulfur content
Some standard content:
GB/T3884.3—2000
This standard adopts two chemical analysis methods to determine the sulfur content in copper concentrate. Method 1 and Method 2 of this standard are reconfirmations of GB/T3884.41983 "Chemical analysis method for copper concentrate - Determination of sulfur content by gravimetric method" and GB/T3884.31983 "Chemical analysis method for copper concentrate - Determination of sulfur content by combustion-volumetric method". The difference from the original standard is that the provision of copper wire as flux is added in Method 2. This standard complies with:
Unit 1: Rules for drafting and expressing standards Part 1: GB/T1.1-1993 Guidelines for standardization work
Basic provisions
GB/T1.4-1988 Guidelines for standardization work Provisions for the preparation of chemical analysis methods GB/T1467-1978 General principles and general provisions for chemical analysis methods for metallurgical products GB/T14265-1993 General principles for analysis of hydrogen, oxygen, nitrogen, carbon and sulfur in metal materials GB/T17433-1998 Basic terms for chemical analysis of metallurgical products This standard replaces GB/T3884.3-1983 and GB/T3884.4-1983 from the date of implementation. This standard is proposed by the State Bureau of Nonferrous Metals Industry. This standard is under the jurisdiction of the China Nonferrous Metals Industry Standard Metrology and Quality Research Institute. This standard is drafted by Daye Nonferrous Metals Company. The main drafting unit of this standard: Jiangxi Copper Company. The main drafters of this standard, Method 1: Guo Chao, Qiu Jiying, Method 2: Li Chunyu, Tao Honglin. 16
1 Scope
National Standard of the People's Republic of China
Chemical analysis method of copper concentrates
Determination of sulfur content
Methods for chemical analysis of copper concentrates-Determination of sulfur contentGravimetric determination of sulfur disk
Method 1
This standard specifies the determination method of sulfur content in steel concentrate. This standard is applicable to the determination of sulfur content in copper concentrate. Determination range: 1.00% ~ 45.00%. 2 Principle of the method
GB/T3884.3-2000
Replaces GB/T3884.3-1983
GB/T3884.4—1983
After the sample is semi-melted with sodium carbonate and zinc oxide at 750℃, the soluble matter is dissolved with water, and the sulfate in the solution is precipitated with fluoride lock. The precipitate is filtered, weighed after burning, and the sulfur content of the sample is calculated according to the mass of the sulfate lock. In the tested material, less than 5mg of fluorine does not interfere with the determination. 3 Reagents
3.1 Sintering agent: Mix one part of anhydrous sodium carbonate with one part of zinc oxide, grind and mix well. 3.2 Hydrochloric acid (p1.19g/mL).
3.3 Barium chloride solution (100g/L) is used after filtering. 3.4 Silver nitrate solution (10 g/L): add 3-4 drops of nitric acid (p1.42 g/mL) to every 100 mL of solution. 3.5 Methyl orange indicator (1 g/L).
4 Sample
4.1 The sample particle size should not be greater than 0.082 mm. 4.2 The sample should be dried at 100-105°C for 1 hour and then placed in a desiccator to cool to room temperature. 5 Analysis steps
5.1 Test material
Weigh the sample according to Table 1, accurate to 0.0001gTable 1
Sulfur content, %
1.00~5.00
>5.00~10.00
>10.00~45.00
Approved by the State Administration of Quality and Technical Supervision on February 16, 2000
Implemented on August 1, 2000
Carry out two independent determinations and take the average value. 5.2 Carry out a blank test together with the test material.
5.3 Determination
GB/T3884.3—2000
5.3.1 Place 2 g of sintering agent in 30 mL of porcelain, fold half a piece of filter paper into a funnel shape and place it in the crucible, add 4 to 6 g of sintering agent, add the sample (5.1), stir evenly, and cover it with a layer of 1 to 2 g of sintering agent. 5.3.2 "Put the crucible on an electric furnace, remove the water at low temperature, and take it off. 5.3.3 Place it in a high-temperature furnace, semi-melt it at 750℃±10℃ for 1.5h, take it out and cool it. 5.3.4 Transfer the semi-melted material into a 400mL beaker containing 100mL of water, wash the crucible with hot water, dilute it to 150mL and boil it for several minutes, filter it into a 500mL beaker with a double-layer medium-speed quantitative filter paper by pouring method, and wash the precipitate with hot water for 8 to 10 times. 5.3.5 Add 1 to 2 drops of methyl orange indicator to the filtrate, neutralize it with hydrochloric acid until the solution turns red, and then add 2mL in excess. 5.3.6 Dilute the filtrate with water to a volume of 3 00mL, boil, slowly add 20mL barium chloride solution under constant stirring, boil, and stand at low temperature for 3h.
5.3.7 Filter with slow quantitative filter paper, wash the precipitate with hot water until there is no nitrogen ion [check with silver nitrate solution]. 5.3.8 Put the precipitate together with the filter paper into a 25mL porcelain cup, place it on a low-temperature electric furnace, dry it to ashing, burn it in a high-temperature furnace at 780℃±10℃ for 0.5h, take out the porcelain crucible and place it in a desiccator, cool it to room temperature, weigh it, and repeat the burning until constant. 6 Expression of analysis results
Calculate the percentage of sulfur according to formula (1):
S(%) = (m =m =m) × 0.137 4 × 100mobZxz.net
Wherein: m,—the mass of precipitate and porcelain, g!m-
the mass of porcelain crucible, g:
ms the mass of blank·g;
—the mass of sample 81
—the conversion factor of sulfuric acid to sulfur. 0.1374
The result is expressed to two decimal places.
7Tolerance
The difference between the analysis results of laboratories should not be greater than the tolerance listed in Table 2: Table 2
Sulfur content
1.00~5.00
>5.00~10.00
>10.00~20.00
>20. 00~30. 00
>30.00~40.00
>40.00~45,00
Method 2 Determination of sulfur content by combustion-titration method
8 Scope
This standard specifies the method for determining the sulfur content in copper concentrate. 18
Tolerance
（1）
GB/T3884.3--2000
This standard applies to the determination of sulfur content in copper concentrate. Determination range: 10.00%~ 45.00%. 9 Method Summary
The sample is burned in an air stream at 1250-1300℃ to convert mercury into sulfur dioxide, which is absorbed and oxidized into sulfuric acid by hydrogen peroxide. Methyl red-methylene blue solution is used as a mixed indicator and titrated with sodium hydroxide standard titration solution until the solution changes from purple-red to bright green.
10 Reagents
10.1 Copper wire: purity above 99.95%, diameter 0.25-0.50mm. 10.2 Sodium hydroxide.
10.3 Anhydrous calcium fluoride.
10.4 Hydrogen peroxide absorption solution: Take 50mL hydrogen peroxide (30%) and dilute it to 1L with water. 10.5 Methyl red-methylene blue mixed indicator: Weigh 0.12g methyl red and 0.10g methylene blue (both are finely ground) and dissolve them in 100mL anhydrous ethanol.
10.6 Standard sodium hydroxide titration solution [c(NaOH)=0.10mol/L]. 10.6.1 Preparation: Prepare sodium hydroxide into a saturated solution and place it in a plastic bottle until the solution becomes clear. Take 50mL of the supernatant, dilute to 10L with water without carbon dioxide, and mix well. 10.6.2 Calibration: Weigh three portions of 0.80g (accurate to 0.0001g) of potassium hydrogen phthalate (reference reagent) that has been dried at 100~105℃ for 2h, place in a 300mL conical flask, add 60mL of hot water without carbon dioxide to dissolve, add 2 drops of ethanol solution of phenolic indicator (<10g/L), and titrate with sodium hydroxide standard titration solution until a slightly reddish color is the end point. Perform a blank test along with the calibration.
Calculate the actual concentration of the sodium hydroxide standard titration solution according to formula (2): m
c=（V,-V)×0.2042
Wherein: c--actual concentration of the sodium hydroxide standard titration solution, mol/L; mi
mass of potassium hydrogen phthalate, g;
V--volume of the sodium hydroxide standard titration solution consumed in titrating the potassium hydrogen phthalate solution during calibration, mLV. --volume of the sodium hydroxide standard titration solution consumed in titrating the blank test solution during calibration, mL; 0.2042~
（2）
The mass of potassium hydrogen phthalate equivalent to 1.00mL sodium hydroxide standard titration solution Lc (NaOH) = 1.000mol/L], g/mol.
Take the average of the three calibration results. The range of the three calibration results should not be greater than 4X10-mol/L, otherwise, recalibrate. 11 Instruments and equipment
11.1 High-temperature tubular electric furnace, maximum temperature 1350℃, common temperature 1300℃. 11.2 Thyristor temperature automatic controller (0~1600℃). 11.3 Rotary vane vacuum pump (30L/min). 11.4 Rotor flowmeter (02L/min).
11.5 Conical combustion tube: inner diameter 21mm, outer diameter *25mm, total length 600mm. 11.6 Combustion porcelain boat: 88 mm long; should be pre-burned at 1000℃ for 1 hour before use. 11.7 The sulfur determination device is shown in Figure 1.
12 Test sample
GB/T3884.3-2000
0~1600℃
1-Alkali washing bottle: 2-Acid washing bottle; 3-Drying tower, 4-Rotor flow meter, 5-Combustion tube: 6-Controllable silicon temperature automatic controller, 7-Platinum thermocouple: 8-60mL straight cylindrical separatory funnel + 9-Spring clip: 10-Vacuum pump, 11-Waste liquid bottle: 12-Three-way glass piston; 13-3# curved gas diffusion tube; 1450mL basic burette: 15-Porcelain boat, 16-Tubular combustion furnace, 17-Six-hole gas diffusion tube; 18-Gas jet tube, 19-Distilled water bottle: 20-Bottle containing sodium hydroxide standard solution Figure 1 Combustion capacity legal sulfur device diagram
12.1 The sample particle size should not be greater than 0.082mm. 12.2 The sample should be dried at 100~105℃ for 1h and then placed in a desiccator to cool to room temperature. 13 Analysis Procedure
13.1 Test Material
Weigh the sample according to Table 3, accurate to 0.0001g. Table 3
Sulfur content, %
10.00~35.00
>35.00~45.00
Carry out two independent determinations and take the average value. 13.2 Determination
Test Material Quantity g
13.2.1 Place the test material (13.1) evenly in a combustion porcelain boat, add 0.1~0.2g of copper wire, and place it in a desiccator. ~220V
13.2.2 Turn on the power supply, set the thyristor temperature automatic controller button to the "manual" position, gradually increase the voltage 2 to 3 times, raise the furnace temperature to 1250-1300℃, and set the button to the "automatic" position. 13.2.3 Add 100mL of hydrogen peroxide absorption liquid and 0.5mL of methyl red and methylene blue mixed indicator to the two absorption bottles respectively. 13.2.4 Connect the device according to Figure 1. Turn on the vacuum pump and check the air tightness of the device. Adjust the air flow rate to 0.8-1L/min, and add sodium hydroxide standard titration solution until the absorption liquid turns bright green, and ignore the reading. 13.2.5 Use a nickel-chromium wire hook to quickly push the combustion porcelain boat containing the sample into the highest temperature of the combustion tube, and immediately plug the rubber stopper. After burning for 4 minutes, use sodium hydroxide standard titration solution to titrate the two bottles respectively. Only the absorption liquid in the gas absorption bottle is titrated until the solution changes from purple to bright green. Unplug the glass three-pronged tube connected to the combustion tube, wash the three-pronged tube with water, then open the spring clamps on the two absorption bottles to wash the gas diffusion tube and sand core, and also wash the air inlet hose of the second absorption bottle, and then close the spring clamps. Continue to titrate with sodium hydroxide standard titration solution until the solution changes from purple to bright green. Note: Regardless of whether a new or old combustion tube is used, it should be fully burned at 1250~1300C before starting the measurement, and 1~2 test samples should be pre-burned before the formal test sample can be measured.
14 Expression of analysis results
Calculate the percentage of sulfur according to formula (3)
S(%) = V.× 0. 016 03 × 100 m
--actual concentration of sodium hydroxide standard titration solution, mol/L Where: c
V2--volume of sodium hydroxide standard titration solution consumed during determination, mL.; (3)
m. Mass of sample, g
0.01603--mass of sulfur equivalent to 1.00mL sodium hydroxide standard titration solution [c(NaOH)=1.000mol/L] + g/ mol. The result is expressed to two decimal places.
15 Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 4. 4
Sulfur content
10.0020.00
>20.00~30.00
>30.00~40.00
>40.00~45.00
Allowable difference3-2000
is bright green, unplug the glass three-pronged tube connected to the combustion tube, wash the three-pronged tube with water, then open the spring clamps on the two absorption bottles to wash the gas diffusion tube and sand core, and also wash the air inlet hose of the second absorption bottle, and then close the spring clamps. Continue to titrate with sodium hydroxide standard titration solution until the solution changes from purple-red to bright green, which is the end point. Note, whether using new or old combustion tubes, before starting the measurement, they should be fully burned at 1250~1300C, and 1~2 test samples should be pre-burned before the formal test sample can be measured.
14 Expression of analysis results
Calculate the percentage of sulfur according to formula (3):
S(%) = V.× 0. 016 03 × 100 m
- the actual concentration of the standard sodium hydroxide titration solution, mol/L Where: c
V2-the volume of the standard sodium hydroxide titration solution consumed during the determination, mL.; (3)
m. The mass of the sample, g
0.01603-the mass of sulfur equivalent to 1.00 mL of the standard sodium hydroxide titration solution [c(NaOH)=1.000 mol/L] + g/mol. The result is expressed to two decimal places.
15 Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 4. Filling 4
Sulfur content
10.0020.00
>20.00~30.00
>30.00~40.00
>40.00~45.00
Allowance3-2000
is bright green, unplug the glass three-pronged tube connected to the combustion tube, wash the three-pronged tube with water, then open the spring clamps on the two absorption bottles to wash the gas diffusion tube and sand core, and also wash the air inlet hose of the second absorption bottle, and then close the spring clamps. Continue to titrate with sodium hydroxide standard titration solution until the solution changes from purple-red to bright green, which is the end point. Note, whether using new or old combustion tubes, before starting the measurement, they should be fully burned at 1250~1300C, and 1~2 test samples should be pre-burned before the formal test sample can be measured.
14 Expression of analysis results
Calculate the percentage of sulfur according to formula (3):
S(%) = V.× 0. 016 03 × 100 m
- the actual concentration of the standard sodium hydroxide titration solution, mol/L Where: c
V2-the volume of the standard sodium hydroxide titration solution consumed during the determination, mL.; (3)
m. The mass of the sample, g
0.01603-the mass of sulfur equivalent to 1.00 mL of the standard sodium hydroxide titration solution [c(NaOH)=1.000 mol/L] + g/mol. The result is expressed to two decimal places.
15 Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 4. Filling 4
Sulfur content
10.0020.00
>20.00~30.00
>30.00~40.00
>40.00~45.00
Allowance
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