Some standard content:
Chemical Industry Standard of the People's Republic of China
HG2740-95
Published on July 25, 1995
Ministry of Chemical Industry of the People's Republic of China
Implemented on March 1, 1996
W.bzsoso.cOI Chemical Industry Standard of the People's Republic of China
Superphosphate
1 Subject Content and Scope of Application
HG2740-95
Replaces ZBG21003-87
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of superphosphate. This standard applies to loose superphosphate for agricultural use made by treating phosphate rock with industrial sulfuric acid. Cited standards
GB/T601 Preparation of standard solutions for titration analysis (volumetric analysis) of chemical reagents GB/T603 Preparation methods for chemical reagent preparations and products GB1250 Expression and determination methods for limit values GB/T6274 Fertilizer terms and definitions
GB/T6682 Specifications and test methods for water used in analytical laboratories Packaging of solid chemical fertilizers
GB8569
3 Terms
The terms involved in this standard are quoted from GB/T6274. 4 Technical requirements
4.1 Appearance: colored loose substance.
4.2 Superphosphate shall meet the requirements of Table 1:
Effective phosphorus pentoxide (P20s) content
Free acid (measured in P20s) content
5 Test method
Superior product
Qualified product
Only analytically pure reagents can be used in the analysis; the water used must meet the specifications of grade 3 water (only pH value range and conductivity index are measured) specified in GB/T6682, and the standard titration solutions involved shall be prepared and calibrated in accordance with GB/T601. 5.1 Determination of effective phosphorus pentoxide content Quinoline phosphomolybdic acid gravimetric method (arbitration method) This method is equivalent to the international standard ISO6598:1985. 5.1.1 Principle of the method
Use water and alkaline ammonium citrate solution to extract the effective phosphorus in superphosphate. The orthophosphate ions in the extract react with quinoline molybdate in an acidic medium to form a yellow quinoline phosphomolybdic acid precipitate. After filtering, washing, drying and weighing the precipitate, the phosphorus pentoxide content is calculated based on the precipitate mass.
5.1.2 Reagents and solutions
5.1.2.1 Nitric acid (GB/T626).
5.1.2.2 Sodium molybdate dihydrate. Www.bzxZ.net
5.1.2.3 Citric acid monohydrate (GB/T9855). 5.1.2.4 Quinoline (without reducing agent).
5.1.2.5 Acetone (GB/T686).
5.1.2.6 Nitric acid (GB/T626) solution, 1+1. 5.1.2.7 Ammonia (GB/T631) solution, 2+3. 5.1.2.8 Quinoline reagent:
Solution 1: Dissolve 70g sodium molybdate dihydrate in 150mL water. Solution I: Dissolve 60g citric acid monohydrate in a mixture of 85mL nitric acid (5.1.2.1) and 150mL water, and cool. Solution: Slowly add Solution I to Solution I while stirring. Solution N: Dissolve 5 mL of quinoline in a mixture of 35 mL of nitric acid (5.1.2.1) and 100 mL of water. Solution V: Slowly add solution V to solution II, mix and place for 24 hours before filtering. Add 280 mL of acetone to the filtrate, dilute to 1 L with water, mix, and store in a polyethylene bottle. Keep away from light and heat. 5.1.2.9 Alkaline ammonium citrate solution: 1 L of solution should contain 173 g of citric acid monohydrate and 42 g of nitrogen in the form of ammonia, equivalent to 51 g of ammonia.
Preparation: Use a single-line pipette to draw 10 mL of ammonia solution (5.1.2.7) and place it in a 500 mL volumetric flask pre-filled with 400-450 mL of water, dilute to the mark with water, and mix. Use a single-line pipette to draw two portions of 25 mL of solution from a 500 mL volumetric flask, transfer them into 25 mL of water in advance, add 2 drops of methyl red indicator solution (5.1.2.11), and titrate with sulfuric acid standard titration solution (5.1.2.10) until the solution turns red. b. The nitrogen content (X1) expressed as a percentage of nitrogen by mass in 1 L of ammonia solution is calculated according to formula (1): Xi = 0. × 0.014.01 × 1000
10 × 500
Where: c - concentration of sulfuric acid standard titration solution, mol/L, V - volume of sulfuric acid standard titration solution consumed during determination, mL, FC.VX28.02 .
0.01401 - the mass of nitrogen expressed in grams equivalent to 1.00 mL of sulfuric acid standard titration solution [c(H,SO) = 1.000 mol/L]. The result should be expressed to one decimal place.
c. The volume (V.L) of ammonia solution (5.1.2.7) required to prepare V1L of alkaline ammonium citrate solution is calculated according to formula (2): V=42XV_ 42xv
c.VX28.02-cV
where: c and V are the same as in formula (1).
Measure the volume (V,) calculated according to formula (2) of hydrogen solution (5.1.2.7) and inject it into the reagent bottle. The bottle should be marked with a line indicating the volume of the alkaline ammonium citrate solution to be prepared. The instrument is shown in Figure 1. 2
W.bzsoso.cOIHG2740-95
1-reagent bottle; 2-separating funnel, 3-tube for ammonia gas to pass into the funnel 4-cock; 5-bottle stopper According to the need for 173g of citric acid monohydrate per liter of alkaline ammonium citrate solution, weigh and calculate the required amount of citric acid monohydrate. Then, according to the ratio of 200-250mL of water to dissolve 173g of citric acid monohydrate, prepare a citric acid solution. Slowly inject the solution into the reagent bottle containing ammonia solution through the separating funnel, and cool the bottle with a large amount of cold water, then add water to the mark and mix well. Let it stand for two nights before use. 5.1.2.10 Standard sulfuric acid titration solution: c (No. H2SO) = 0.1mol/L. 5.1.2.11 Methyl red (HG/T3-958) indicator solution: 2g/L. Weigh 0.2g of methyl red and dissolve it in 100mL of 60% (V/V) ethanol solution. 5.1.3 Instruments
Usually used laboratory instruments and:
5.1.3.1 Glass crucible filter: No. 4 (average filter pore size 5~15um), volume 30mL. 5.1.3.2 Constant temperature drying oven: capable of controlling temperature (180±2)℃. 5.1.3.3 Constant temperature water bath: capable of controlling temperature (60±1)℃. 5.1.4 Analysis steps
5.1.4.1 Sample preparation: Sampling and sample preparation according to 6.5~6.8. 5.1.4.2 Extraction of available phosphorus: Weigh 2-2.5g of sample (accurate to 0.001g), place in a 75mL evaporating dish, grind the sample with a glass pestle, add 25mL of water to grind again, pour the supernatant and filter it into a 250mL volumetric flask that has been pre-added with 5mL of nitric acid solution (5.1.2.6). Continue grinding with water three times, using 25mL of water each time, then transfer the water-insoluble matter to the filter paper, and wash the water-insoluble matter with water until the volume of the solution in the volumetric flask is about 200mL, dilute with water to the mark, and mix well. This is solution A. Transfer the filter paper containing the water-insoluble matter to another 250mL volumetric flask, add 100mL of alkaline ammonium citrate solution (5.1.2.9), cover the bottle with a stopper, and shake until the filter paper is broken into fibers. Place the volumetric flask in a constant temperature water bath at (60±1)℃ for 1h. At the beginning, shake the volumetric flask once every 5 minutes, shake it three times and then shake it every 15 minutes. Take out the volumetric flask, cool it to room temperature, dilute it with water to the mark, and mix it. Filter it with dry blood and filter paper, discard the first few milliliters of filtrate, and the filtrate obtained is solution B. 5.1.4.3 Determination of available phosphorus: Use a single-line pipette to draw 10-20mL of solution A and solution B (containing P20s ≤ 20mg) respectively into a 300mL beaker, add 10mL nitric acid solution (5.1.2.6), dilute it with water to 100mL, cover it with blood, preheat it to near boiling, and add 35mL3
WHG2740-95
quinomolybdate reagent (5.1.2.8) Boil slightly for 1 minute or place in a water bath at about 80℃ to keep warm until the precipitate is separated, cool to room temperature, and rotate the beaker 3 to 4 times during the cooling process.
Use a No. 4 glass crucible filter that has been dried to constant weight in a constant temperature drying oven at (180±2)℃ to filter, first filter out the upper clear liquid, wash the precipitate 1 to 2 times by pouring method (about 25mL of water each time), then transfer the precipitate to the filter, and continue to wash with water, using a total of about 125 to 150mL of water, place the filter with the precipitate in a constant temperature drying oven at (180±2)℃, dry for 45 minutes after the temperature reaches 180℃, transfer to a desiccator to cool to room temperature, and weigh.
5.1.4.4 Blank test: except for not adding the sample, follow the same determination steps as above, use the same reagents, solutions, and dosages. 5.1.5 Expression of analysis results
The effective phosphorus content (X2) expressed as the mass percentage of phosphorus pentoxide (P2Os) is calculated according to formula (3): Xx=(m1m)X0. 032 07×100..
m×500
Wherein: m1—mass of quinoline phosphomolybdic acid precipitation, gm2—mass of quinoline phosphomolybdic acid precipitation obtained in the blank test, g; m——mass of sample, 8,
V——total volume of the absorbed test solution (solution A + solution B), mL, 0.03207—coefficient for converting the mass of quinoline phosphomolybdic acid into the mass of phosphorus pentoxide. 5.1.6 Allowable difference
(3)
5.1.6.1 Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.20%. 5.1.6.2 The absolute difference between the results of different laboratories shall not exceed 0.30%. 5.2 Determination of the content of effective phosphorus pentoxide: quinoline phosphomolybdic acid volumetric method 5.2.1 Principle of the method
Use water and alkaline ammonium citrate solution to extract the effective phosphorus in superphosphate. The orthophosphate ions in the extract react with the quinoline phosphomolybdic acid reagent in an acidic medium to form a yellow quinoline phosphomolybdic acid precipitate. After filtering and washing the adsorbed acid solution, the precipitate is dissolved in an excess of a standard alkali titration solution, and then back-titrated with an acid standard titration solution. The phosphorus pentoxide content is calculated based on the volume of the acid and alkali solutions used. 5.2.2 Reagents and solutions
Same as 5.1.2 and:
5.2.2.1 Sodium hydroxide (GB/T629) solution, 4 g/L. 5.2.2.2 Carbon dioxide-free water, prepared according to 4.1.2 of GB/T603. 5.2.2.3 Standard titration solution of sodium hydroxide (GB/T629): c(NaOH)=0.5mol/L. 5.2.2.4 Standard titration solution of hydrochloric acid (GB/T622), c(HC1)=0.25mol/L. 5.2.2.5 Mixed indicator solution:
Indicator solution a: Dissolve 0.1g thymol blue (HG/T3-1223) in 2.2mL sodium hydroxide solution (5.2.2.1), and dilute to 100mL with 50% (V/V) ethanol solution.
Indicator solution b: Dissolve 0.1g phenol (GB/T10729) in 100mL 60% (V/V) ethanol solution. Take 3 volumes of indicator solution a and 2 volumes of indicator solution b and mix them evenly. 5.2.3 Instruments
Usually used laboratory instruments and:
5.2.3.1 Constant temperature water bath: can control the temperature (60 ± 1) ℃. 5.2.3.2 25mL acid burette.
5.2.4 Analysis steps
5.2.4.1 Sample preparation: same as 5.1.4.1. 5.2.4.2 Extraction of available phosphorus: same as 5.1.4.2. 4
WHG274095
5.2.4.3 Determination of available phosphorus: Follow the steps specified in 5.1.4.3 until "turn the beaker 3 to 4 times during cooling", and then follow the steps below. Filter with a filter (the filter can be lined with filter paper, absorbent cotton, etc.), first filter out the upper clear liquid, and then wash the precipitate 3 to 4 times by pouring method, each time with about 25mL of water. Transfer the precipitate to the filter, then wash the precipitate with water until about 20 mL of filtrate is obtained, add a drop of mixed indicator solution (5.2.2.5) and 2 to 3 drops of sodium hydroxide solution (5.2.2.1) until the filtrate turns purple. Transfer the precipitate together with the filter paper or absorbent cotton to the original beaker, add sodium hydroxide standard solution (5.2.2.3), stir thoroughly to dissolve the precipitate, then add 810 mL in excess, add 100 mL of carbon dioxide-free water (5.2.2.2), stir the solution, add 1 mL of mixed indicator solution (5.2.2.5), and titrate with hydrochloric acid standard titration solution (5.2.2.4) until the solution changes from purple to gray-blue to yellow, which is the end point. 5.2.4.4 Blank test: Except for not adding the sample, follow the above determination steps and use the same reagents, solutions, and dosages. 5.2.5 Expression of analysis results
The effective phosphorus content (X:) expressed as the mass percentage of phosphorus pentoxide (P20s) is calculated according to formula (4): [cr(V/-V)-c2(V2-V)))X0.002 730Xg=
m×500
Wherein: V—total volume of the test solution (solution A+solution B) absorbed, mLV1—volume of sodium hydroxide standard titration solution consumed, mL; V2——volume of hydrochloric acid standard titration solution consumed, mL, V3—volume of sodium hydroxide standard titration solution consumed in the blank test, mL, V—volume of hydrochloric acid standard titration solution consumed in the blank test, mL, C——concentration of sodium hydroxide standard titration solution, mol/L; C2——concentration of hydrochloric acid standard titration solution, mol/L, m——mass of sample, g,
0.002730——mass of phosphorus pentoxide expressed in grams equivalent to 1.00mL sodium hydroxide standard titration solution (c(Na0H)—1.000mol/L].| |tt||5.2.6 Allowable difference
Same as 5.1.6.
5.3 Determination of effective phosphorus pentoxide content
5.3.1 Principle of the method
Ammonium vanadium platinate spectrophotometry
Water: Alkaline ammonium citrate solution is used to extract the effective phosphorus in superphosphate. The orthophosphate ions in the extract react with molybdate and metavanadate in an acidic medium to form a stable yellow complex. The absorbance is determined by the differential method at a wavelength of 420nm, and the phosphorus pentoxide content is calculated.
5.3.2 Reagents and solutions
5.3.2.1 Color reagents
Solution a: Dissolve 1.12g of ammonium metavanadate (HG/T3-941) in 150mL of hot water at about 50℃, add 150mL of nitric acid (5. 1.2.1).
Solution b: Dissolve 50.0g of ammonium molybdate (GB/T657) in 300mL of hot water at about 50℃. Then slowly add solution b while stirring solution a, dilute to 1000mL with water, and store in a brown bottle. If precipitation is generated during storage, it cannot be used.
5.3.2.2 Phosphorus pentoxide standard solution: Weigh 19.175g of potassium dihydrogen phosphate (GB/T1274) dried at 105℃ for 2h, dissolve it in a small amount of water, and quantitatively transfer it into a 1000mL volumetric flask, add 23mL of nitric acid (5.1.2.1), Dilute with water to the mark and mix well (1 mL of this solution contains 10 mg of phosphorus pentoxide). Then take 5.0, 10.0, 15.0, 20.0, 25.0, 30.0, and 35.0 mL of this solution into a 500 mL volumetric flask, dilute with water to the mark and mix. Prepare standard solutions containing 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, and 7.0 mg of phosphorus pentoxide in 10 mL of solution.
W.5.3.3 Instruments
HG274095
Usually used laboratory instruments and spectrophotometers: with 1 cm absorption cells. 5.3.4 Analysis steps
5.3.4.1 Sample preparation: Same as 5.1.4.1. 5.3.4.2 Extraction of available phosphorus: Weigh 2-2.5g sample (accurate to 0.001g), place in 75mL evaporation III, grind the sample with a glass pestle, add 25mL water to grind again, pour the clear liquid into the pre-added 10mL nitric acid solution (5.1.2.6) into a 500mL volumetric flask. Continue grinding with water three times, using 25mL of water each time, then transfer the water-insoluble matter to the filter paper, and wash the water-insoluble matter with water until the volume of the solution in the volumetric flask is about 200mL, dilute with water to the mark, and mix well. This is solution A. Transfer the filter paper containing the water-insoluble matter to another 500mL volumetric flask, add 100mL of alkaline ammonium citrate solution, cover the bottle stopper, and shake until the filter paper is broken into fibers. Place the volumetric flask in a (60±1)℃ constant temperature water bath and keep warm for 1h. At the beginning, shake once every 5min, shake three times and then shake once every 15min, take out the volumetric flask, cool to room temperature, dilute with water to the mark, and mix well. Filter with a dry vessel and filter paper, discard the first few milliliters of filtrate, and the resulting filtrate is solution B. 5.3.4.3 Determination of available phosphorus: Use a single-line pipette to pipette 5 mL each of solution A and solution B (containing 1.0-6.0 mg P20) into a 100 mL beaker, add 1 mL of alkaline ammonium citrate solution (5.1.2.9), 4 mL of nitric acid solution (5.1.2.6) and an appropriate amount of water, heat and boil for 5 min, cool, transfer to a 100 mL volumetric flask, dilute with water to about 70 mL, accurately add 20.0 mL of colorimetric reagent (5.3.2.1), dilute with water to the mark, mix well, let stand for 30 min, and then determine at a wavelength of 420 nm using the following method. Accurately pipette two portions of phosphorus pentoxide standard solution (5.3.2.2), one portion with a lower P205 content than the sample solution, and the other portion with a higher P205 content than the test solution (the difference between the two concentrations is 1 mg P205), and place them in 100 mL volumetric flasks respectively. Add 2 mL of alkaline ammonium citrate solution (5.1.2.9) and 4 mL of nitric acid solution (5.1.2.6), and perform the same color development operation as the sample solution to prepare standard solution 1 and standard solution 2. Take standard solution 1 as the reference solution (take the absorbance of this solution as zero), and measure the absorbance of standard solution 2 and the sample solution. Calculate the content of phosphorus pentoxide in the sample solution using the proportional relationship.
5.3.5 Expression of analysis results
The effective phosphorus content (X) expressed as the mass percentage of phosphorus pentoxide (P206) is calculated according to formula (5): 8+A
Si+(82-8)X
XA2×100
X1-000
m·i000
Wherein: S1——phosphorus pentoxide content in standard solution 1, mg, S2——phosphorus pentoxide content in standard solution 2, mgS2—81——equal to 1mg,
A——absorbance of sample solution;
A2——absorbance of standard solution 2;
mass of sample, g.
5.3.6 Allowable difference
Same as 5.1.6.
5.4 Determination of free acid content by volumetric method
5.4.1 Principle of the method
+A2X10
Use sodium hydroxide solution to titrate the free acid. The free acid content is calculated based on the amount of sodium hydroxide standard titration solution consumed. 5.4.2 Reagents and solutions
5.4.2.1 Standard titration solution of sodium hydroxide (GB/T629): c(NaOH) = 0.1 mol/L. 5.4.2.2 Bromocresol green (HG/T3-1220) indicator solution: 2 g/L. (5)
Weigh 0.2 g of bromocresol green and dissolve it in 6 mL of sodium hydroxide solution (5.4.2.1) and 5 mL of ethanol (GB/T679), and dilute to 100 mL with water.
W5.4.3 Instruments
Usually used laboratory instruments and:
5.4.3.1 Acidity meter: ±0.02pH.
5.4.3.2 Magnetic stirrer.
HG2740—95
5.4.3.310mL basic burette: graduation value 0.05mL. 5.4.3.4 Oscillator: about 40r/min.
5.4.4 Analysis steps
5.4.4.1 Sample preparation: Same as 5.1.4.1. 5.4.4.2 Acidity meter method (arbitration method): Weigh 5g sample (accurate to 0.01g), transfer to a 250mL volumetric flask, add 100mL water, shake for 15min, dilute to scale, mix, dry filter, and discard the initial filtrate. Use a single-line pipette to draw 50 mL of the filtrate into a 250 mL beaker, dilute with water to 150 mL, place the beaker on a magnetic stirrer, immerse the electrode in the solution to be tested, insert the magnetic needle, and titrate with sodium hydroxide standard titration solution (5.4.2.1) to pH 4.5 while stirring on the positioned acidometer.
5.4.4.3 Indicator method: draw 50 mL of the filtrate in (5.4.4.2) (if the filtrate is turbid, reduce the amount drawn appropriately) into a 250 mL conical flask, dilute with water to 150 mL, add 0.5 mL of bromocresol green indicator solution (5.4.2.2), and titrate with sodium hydroxide standard titration solution (5.4.2.1) until the solution turns pure green as the end point. 5.4.5 Expression of analysis results
The free acid content (Xs) expressed as a percentage of the mass of phosphorus pentoxide (P2Os) is calculated according to formula (6): X
m·250
Wherein: c——concentration of sodium hydroxide standard titration solution, mol/L; volume of sodium hydroxide standard titration solution consumed in one titration, mL; V
V——volume of the absorbed test solution, mL,
m——mass of the sample, g;
+（6）
0.0710——mass of phosphorus pentoxide expressed in grams equivalent to 1.00mL of sodium hydroxide standard titration solution [c(Na0H)=1.000mol/L].
5.4.6 Allowable difference
5.4.6.1The arithmetic mean of the parallel determination results shall be taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.15%. 5.4.6.2 The absolute difference between the results of different laboratories shall not exceed 0.30%. 5.5 Determination of moisture content Oven drying method
5.5.1 Principle of the method
At a certain temperature, the loss of the sample after drying for 3 hours is the moisture content. 5.5.2 Instruments
Usually laboratory instruments and:
5.5.2.1 Constant temperature oven: The temperature can be controlled at (100 ± 2) ℃. 5.5.2.2 Weighing bottle: The diameter is 50mm and the height is 30mm. 5.5.3 Analysis steps
5.5.3.1 Sample preparation: Same as 5.1.4.1. 5.5.3.2 Weigh 10g of sample (accurate to 0.01g), spread evenly in a weighing bottle that has been dried at (100±2)℃ in advance, place in a constant temperature oven, the weighing bottle should be close to the level of the mercury ball of the thermometer, dry for 3h, take out, put in a desiccator to cool for 30min and weigh. 5.5.4 Expression of analysis results
The water content (H20O) (X) expressed as mass percentage is calculated according to formula (7): 7
Wbzsoso,cO Where: m-
mass of the sample before drying, g,
mass of the sample after drying, 8.
5.5.5 Allowable difference
HG2740—95
5.5.5.1 Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.20%. 5.5.5.2 The absolute difference of the determination results of different laboratories shall not exceed 0.40%. 6 Inspection rules
6.1 This standard adopts the "rounded value comparison method" in GB1250 to judge whether the inspection results meet the standard. (7)
6.2 Superphosphate shall be inspected by the product quality supervision and inspection department of the manufacturer. The manufacturer shall ensure that all superphosphate shipped out of the factory meets the requirements of this standard. Each batch of products shipped out of the factory shall be accompanied by a quality certificate, which includes: manufacturer name and address, product name, net weight, grade, production date (or batch number), license number and this standard number. 6.3 The user has the right to inspect the quality of the superphosphate received in accordance with the test methods and inspection rules specified in this standard to verify whether its indicators meet the requirements of this standard. 6.4 If one indicator in the inspection results does not meet the requirements of this standard, re-sampling should be carried out from twice the amount of packaging units for re-inspection. If even one indicator in the re-inspection results does not meet the requirements of this standard, the entire batch of superphosphate cannot be accepted. 6.5 Superphosphate fertilizers are inspected in batches, with one or two days' output as one batch.
6.6 Superphosphate is sampled in the following manner: 6.6.1 Bag sampling
Determine the number of sampling bags according to the requirements of Table 2.
Total number of packaging bags
82~101
102~125
126~151
152~181
Sampling bags
Total number of bags
Total number of packaging bags
182~216
217~254
255~296
297~343
344~394
395~450
451~512
When the number exceeds 512 bags, calculate the number of sampling bags according to formula (8). If a decimal is encountered, it shall be rounded up to an integer. Number of sampling bags = 3×3N
Where: N——Total number of bags of fertilizer per batch.
Number of sampling bags
Calculate the results according to Table 2 or formula (8), extract the number of sample bags, insert the sampling needle from the longest diagonal line of each bag to one-third of the bag, and take out no less than 100g of sample. The total amount of sampling per batch shall not be less than 2kg. 6.6.2 Bulk transportation sampling
Samples are collected in each transport unit (train, car, ship, etc.) as a batch. When sampling, the number of sampling points is determined according to the following method: if the batch is less than 2.5t, the sampling is 7 points;
The number of sampling points is calculated according to formula (9) for batches of 2.5 to 80t. If a decimal is encountered, it is rounded up to an integer; W.HG2740-95
Number of sampling points = √Batch (t)×20
c. If the batch is greater than 80t, the number of sampling points is 40. (9)
After the number of sampling points is determined according to the above method, sampling is carried out according to Figure 2 at a distance of not less than 0.3m from the vehicle wall or ship. When sampling, use sampling tools such as sampling needles to collect samples at a depth of at least 0.2m from the surface of the sampling point. The amount of sample collected at each point shall not be less than 100g, and the total amount of sample collected shall not be less than 2kg.
6.6.3 Sampling on the conveyor
From the beginning of loading and unloading of each batch of superphosphate to the end of loading and unloading, according to the total amount of superphosphate and the conveying speed of the conveyor, uniform and representative samples are collected on the conveying cross section at certain intervals. The amount of sample collected each time shall not be less than 100g, and the total amount of sample collected shall not be less than 2kg. 6.6.4 Sampling of product piles
After the number of sampling points is determined according to the bulk method, on the slope of the product pile, from about 0.3m from the bottom to the part that can be reached, several horizontal lines are drawn, and sampling is carried out according to Figure 3 at a certain distance on each line. When sampling, use sampling tools such as sampling needles to collect samples at a depth of 0.2m from the surface of the sampling point. The amount of samples collected at each sampling point shall not be less than 100g, and the total amount of samples collected shall not be less than 2kg. Figure 3
6.7 Sample reduction: Combine the selected samples of each batch and mix them thoroughly, then use the quartering method to reduce them to no less than 500g, and pack them in two clean, dry wide-mouth bottles or polyethylene bottles with caps with ground stoppers. Label them with the manufacturer's name, product name, batch number, sampling date and the name of the sampler. One bottle is used for sample preparation, and one bottle is sealed and stored for 2 months for inspection. 6.8 Sample preparation: Before analysis, the sample collected should be crushed to no more than 2mm, mixed evenly, and reduced to about 100g by quartering method, and placed in a clean, dry bottle for quality analysis. 6.9 When the supply and demand parties have disputes over product quality and need arbitration, arbitration shall be conducted in accordance with the relevant provisions of the "Product Quality Law of the People's Republic of China". Arbitration shall be conducted in accordance with the test methods and inspection rules specified in this standard. 7 Packaging, marking, transportation and storage
7.1 The packaging of superphosphate shall be carried out in accordance with the provisions of GB8569. The net weight of each bag shall be (25.0±0.5)kg or (50.0±1.0)kg, and the average net weight of each bag shall not be less than 25.0kg or 50.0kg. 7.2 The following marks shall be printed on the packaging bag of superphosphate: product name, trademark, effective phosphorus pentoxide content, net weight, this standard number, production license number, manufacturer name, factory address. 7.3 Superphosphate is partially soluble in water. When transported in bulk in vehicles or ships, the compartments shall be sealed, the doors shall be closed, the ships shall have pads, and covered with corrosion-resistant tarpaulins.
W.bzsoso.cOI10
HG 274095
Superphosphate should be protected from moisture, sunlight and damage to the packaging bag during storage and transportation. Additional remarks:
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry. This standard is under the jurisdiction of the Shanghai Research Institute of Chemical Industry of the Ministry of Chemical Industry. This standard was drafted by the Shanghai Research Institute of Chemical Industry of the Ministry of Chemical Industry. The main drafters of this standard are Li Liangjun, Qian Zhixing, Yang Zeqin and Lou Shizhi. W.
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