Some standard content:
Record number: 7257-2000
HG/T2226-2000
This standard is a revision of the chemical industry standard HG/T22261991 "Industrial Precipitated Calcium Carbonate" by adopting the German standard DIN55918:1984 "Calcium Carbonate for Fillers" in a non-equivalent manner. The main technical differences between this standard and the German standard are as follows: It is divided into three levels according to the actual situation in my country. The copper content index in the standard is cancelled, and the iron and sedimentation volume indexes specially required by users are added. The manganese content and volatile matter indexes at 105℃ are better than the German standard. The main technical differences between this standard and HG/T2226-1991 are: According to user requirements, the water-soluble project index is added, and its index parameters and test methods are equivalent to the German standard. The main content and pH value index are equivalent to the German standard. The qualified product index of iron content is adjusted to make it more in line with national conditions. This standard will replace HG/T2226--1991 from the date of implementation. This standard is proposed by the Policy and Regulations Department of the State and Petrochemical Industry Bureau. This standard is under the jurisdiction of the Inorganic Chemical Branch of the National Technical Committee for Chemical Standardization. The drafting units of this standard are: Tianjin Chemical Research and Design Institute, Zhejiang Linghua Group Co., Ltd., and Sichuan Dujiangyan Calcium Products Co., Ltd. The main drafters of this standard are: Yao Jinjuan, Ruan Shixiang, and Wang Liangjin. This standard was first issued in 1984 and was first revised in 1991. This standard is entrusted to the Inorganic Chemical Branch of the National Technical Committee for Chemical Standardization for interpretation. 378
1 Scope
Chemical Industry Standard of the People's Republic of China
Industrial Precipitated Calcium Carbonate
Calcium carbonate precipitated for industrial useHG/T 2226--2000
Replaces HG/T2226-1991
This standard specifies the requirements, test methods, inspection regulations, as well as marking, labeling, packaging, transportation and storage of industrial precipitated calcium carbonate. This standard applies to industrial precipitated calcium carbonate made from limestone by carbonization. This product is mainly used as a filler in industries such as rubber, plastics, papermaking and coatings.
Molecular formula: CaCO:
Relative molecular mass: 100.09 (according to the 1997 international relative atomic mass) 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were all valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest versions of the following standards. GB191--1990 Pictorial markings for packaging, storage and transportation
GB/T 601--1988
Preparation of standard solutions for titration analysis (volume analysis) of chemical reagents GB/T 602--1988
GB/T 603--1988
GB/T 1250—1989
GB/T 3049—1986
GB/T 6678--1986
GB/T 6682--1992
GB/T 9087—1988
3 Technical requirements
3.1 Appearance: white powder.
Chemical reagents
Preparation of standard solutions for impurity determination (neqISO6353-1:1982)Preparation of preparations and products used in test methods (neqISO6353-1:1982)Chemical reagents
Methods for expressing and determining limit valuesGeneral method for determination of iron content in chemical products-o-phenanthroline spectrophotometry (negISO6685:1982)
General rules for sampling of chemical products
Specifications and test methods for water used in analytical laboratories (neqISO3696:1987)Powder standard white board for colorimetric and photometric measurementsIndustrial precipitated calcium carbonate shall comply with the requirements of Table 1. 3.2
Requirements in Table 1
Calcium carbonate (CaCO,) content (dry basis)/%pH value (10% suspension)
Volatile matter content at 105℃/%
Content of hydrochloric acid insoluble matter/%
Approved as a superior product by the State Administration of Petroleum and Chemical Industry on 2000-05-23
9. 0～10. 0
First-class products
Qualified products
2000-12-01 implementation
Sedimentation volume/(rmL/g)
Iron (Fe) content/%
Manganese (Mn) content/%
Sieve residue: 125μm test sieve/%
45μm test sieve/%
Whiteness/degree
Water-soluble matter/%
Test method
HG/T2226--2000
Table 1 (end)
Superior products
·Equal products
Qualified products
The reagents and water used in this standard, unless otherwise specified, refer to analytical pure reagents and Grade 3 water specified in GB/T6682. The standard titration solutions, impurity standard solutions, preparations and products used in this standard shall be prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603 unless otherwise specified.
Safety Tips: The strong acids and alkalis used in this standard are corrosive. Users should be careful when handling them. If they splash on the skin, rinse immediately with plenty of water. In severe cases, seek medical treatment immediately.
4.1 Determination of Calcium Carbonate Content
4.1.1 Method Summary
A small amount of A13+, Fe3+, Mn2+ ions are masked with triethanolamine. In a medium with a pH value greater than 12, the calcium reagent carboxylate sodium salt is used as an indicator and titrated with a standard titration solution of disodium ethylenediaminetetraacetic acid. 4.1.2 Reagents and Materials
4.1.2.1 Hydrochloric acid solution: 1+1.
4.1.2.2 Sodium hydroxide solution: 100g/I. 4.1.2.3
Triethanolamine solution: 1+3.
4.1.2.4 Ethylenediaminetetraacetic acid disodium standard titration solution: c(EDTA) is about 0.02mol/L. 4.1.2.5 Calcium reagent carboxylate sodium salt indicator. Weigh 10g of sodium chloride dried at 105℃~～110℃ for 2h, put it in a mortar and grind it finely, add 0.1g of calcium reagent carboxylate sodium salt, grind it finely, and mix it well. Put it in a weighing bottle and store it in a desiccator. 4.1.3 Analysis steps
Weigh 0.6g of the sample that has been dried to constant weight at 105℃～110℃ in advance (accurate to 0.0002g), put it in a 250mL beaker, add a little water to moisten it, cover it with surface III, add hydrochloric acid solution until the sample is completely dissolved, transfer it all into a 250mL volumetric flask, dilute it to the scale with water, and shake it. Use a pipette to transfer 25 ml of the test solution into a conical flask, add 5 ml of triethanolamine solution, 25 ml of water and a small amount of calcium reagent carboxylic acid sodium salt indicator, adjust to wine red with sodium hydroxide solution, and titrate with disodium ethylenediaminetetraacetic acid standard titration solution until pure blue is the end point.
At the same time, perform a blank test.
4.1.4 Expression of analysis results
Calcium carbonate (CaCO.) content (X,) expressed as mass fraction is calculated according to formula (1): X = c(V--Vo) X0. 1001 X
m×250
Wherein:
China Power
The volume of disodium ethylenediaminetetraacetic acid standard titration solution consumed by the titration test solution, mL; (1)
HG/T 2226—2000
The volume of disodium ethylenediaminetetraacetic acid standard titration solution consumed by the titration blank solution, ml; The actual concentration of disodium ethylenediaminetetraacetic acid standard titration solution, mol/L; m
0. 100 1-
-mass of the sample, g;
mass of calcium carbonate equivalent to 1.00mL of disodium ethylenediaminetetraacetic acid standard titration solution Lc (EDTA) 1.000mol/L.].
4.1.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.2%. 4.2 Determination of pH value
4.2.1 Instruments and equipment
4.2.1.1 Acidometer: The measurement range is pH 0 to 14, and the minimum scale value is 0.02pH. 4.2.1.2 Reference electrode: calomel electrode, filled with saturated potassium chloride solution. 4.2.1.3 Measuring electrode: glass electrode.
4.2.2 Analysis steps
Connect the reference electrode and measuring electrode to the acidometer, preheat, zero and position. Weigh (10 ± 0.01) g sample, place in a 150 mL beaker, add 100 mL of water without carbon dioxide, stir thoroughly, let stand for 10 minutes, and measure the pH value of the suspension with an acidometer. 4.2.3 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.3 pH. 4.3 Determination of volatile content at 105°C
4.3.1 Analysis steps
Weigh about 2g of sample (accurate to 0.0002g), place it in a weighing bottle with constant weight, move it into a constant temperature drying oven, and dry it at 105~～110°C to constant weight.
4.3.2 Expression of analysis results
The volatile content at 105°C expressed as mass fraction (X,) is calculated according to formula (2): Xe=m=m2×100
Where: m1--the mass of the weighing bottle and sample before drying, g; the mass of the weighing bottle and sample after drying, g; mz
m--the mass of the sample, g.
4.3.3 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.02%. 4.4 Determination of hydrochloric acid insoluble matter
4.4.1 Method summary
Dissolve the sample with hydrochloric acid, filter the acid insoluble matter, burn, and weigh. 4.4.2 Reagents and materials
4.4.2.1 Hydrochloric acid dissolution: 1+1.
4.4.2.2 Silver nitrate solution: 10g/L.
4.4.3 Instruments and equipment
High temperature furnace: capable of controlling the temperature at (875±25)℃. 4.4.4 Analysis steps
Weigh about 4g (2g for qualified products) of sample (accurate to 0.01g). Place in a beaker, add a small amount of water to moisten, add 20mL (10mL for qualified products) of hydrochloric acid solution, heat to boiling, filter with medium-speed quantitative filter paper while hot, and wash with hot water until there is no chloride ion in the filtrate (check with silver nitrate solution). Transfer the filter paper together with the insoluble matter into the porcelain crucible with constant weight, incinerate at low temperature, transfer to a high temperature furnace, and burn at (875±25)℃ for 381℃ to constant weight.
4.4.5 Expression of analysis results
HG/T 2226—2000
The hydrochloric acid insoluble matter content (X,) expressed as mass fraction is calculated according to formula (3): X: = m=m2×100
Wherein: m-
The mass of the porcelain crucible and insoluble matter after burning, g; The mass of the porcelain crucible, g;
The mass of the sample, g.
4.4.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.03%. 4.5 Determination of sedimentation volume
4.5.1 Instruments and equipment
Graduated measuring cylinder with ground stopper: 100ml.
4.5.2 Analysis steps
Weigh (10±0.01)g of sample and place it in a graduated cylinder with ground stopper containing 30mL of water. Add water to the scale and shake up and down for 3min (100 times/min～110 times/min). Let it stand at room temperature for 3h and record the volume occupied by the sediment (mL). 4.5.3 Expression of analysis results
The sedimentation volume (X) expressed as the volume occupied by each gram of sediment is calculated according to formula (4): V
Where: V
Volume occupied by sediment, mL;
mMass of sample, g.
4.5.4 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.1 mL/g. 4.6 Determination of iron content
4.6.1 Summary of the method
Same as Chapter 1 of GB/T3049-1986.
4.6.2 Reagents and materials
4.6.2.1 Nitric acid solution: 1+1.
4.6.2.2 Nitric acid solution: 1+6.
Others are the same as Chapter 3 of GB/T3049-1986.
4.6.3 Instruments and equipment
Spectrophotometer: with an absorption cell with a thickness of 1 cm. 4.6.4 Analysis steps
4.6.4.1 Preparation of test solution A
Weigh about 20g of sample (accurate to 0.01g), place in a tall beaker, add 10mL of water to moisten, cover the surface with blood, slowly add 65mL of nitric acid solution (4.6.2.1), heat to boiling, filter with medium-speed quantitative filter paper, wash, collect the filtrate and washing liquid in a 250mL volumetric flask, add water to the scale, and shake well. This solution is test solution A, which is used to determine the iron content and manganese content. 4.6.4.2 Preparation of blank test solution
Measure 1mL of nitric acid solution (4.6.2.2), place in a beaker, add 10mL of water, and set aside. 4.6.4.3 Drawing of working curve
According to the provisions of 5.3 of GB/T3049-1986, select an absorption cell with a thickness of 1 cm and the corresponding amount of iron standard solution, and draw the working curve.
4.6.4.4 Determination
HG/T 2226-2000
Use a pipette to transfer 25 mL of test solution A, place it in a 250 mL volumetric flask, add water to the scale, and shake it. Use a pipette to transfer 25 ml., place it in a 100 mL beaker, and at the same time as the blank solution, follow the provisions of 5.4 of GB/T3049-1986, starting from "If necessary, add water to 60 mL.".
Select a 1 cm absorption cell, measure the absorbance according to the provisions of 5.4 of GB/T3049--1986, and find out the mass of iron in the test solution and blank solution according to the working curve.
4.6.5 Expression of analysis results
The iron (Fe) content (X) expressed as mass fraction is calculated according to formula (5): Xs
m××2×
10(mi-mo)
X 100
Wherein: ml-the mass of iron in the test solution found from the working curve, mg; m.——the mass of iron in the blank solution found from the working curve, mg; m---the mass of the sample, g.
4.6.6 Allowable differencebzxZ.net
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.01%. 4.7 Determination of manganese content
4.7.1 Method summary
In a strong acidic medium in the presence of phosphoric acid, potassium periodate oxidizes divalent manganese ions into purple-red permanganate ions when heated and boiled, and its absorbance is measured by a spectrophotometer. 4.7.2 Reagents and materials
4.7.2.1 Potassium periodate.
4.7.2.2 Phosphoric acid solution: 1+1.
4.7.2.3 Ammonia solution: 2+3.
4.7.2.4 Manganese standard solution: 1mL solution contains 0.01mgMn. Use a pipette to transfer 25mL of the manganese standard solution prepared according to GB/T602, place it in a 250mL volumetric flask, dilute it to the mark with water, shake it well, and prepare the dilution before use.
4.7.3 Instruments and equipment
Spectrophotometer: with an absorption cell of 3 cm thickness. 4.7.4 Analysis steps
4.7.4.1 Working curve drawing
Use a pipette to transfer: 0mL, 1mL, 5mL, 10mL, 15mL, 20mL and 25mL of manganese standard solution, respectively, and place them in 250mL beakers, add 40mL of water, 1.5mL of nitric acid solution (4.6.2.2), 10mL of phosphoric acid solution and 0.3g of potassium periodate, cover with blood, heat to boiling, boil for 3min, cool and transfer all to a 100mL volumetric flask, add water to the scale, and shake. At a wavelength of 525nm, use a 3cm absorption cell, take water as reference, adjust the absorbance of the spectrophotometer to zero, and measure the absorbance.
Use the manganese content as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. 4.7.4.2 Preparation of blank solution
Measure 5 mL of nitric acid solution (4.6.2.1) and place it in a beaker. Adjust the pH value to 7 with ammonia solution (check with pH test paper), and then add 1.5 ml of nitric acid solution (4.6.2.2). 4.7.4.3 Determination
Use a pipette to transfer 25 mL of test solution A and place it in a 250 mL beaker. Simultaneously with the blank solution, perform the operation as specified in 4.7.4.1, starting from "adding 10 mL of phosphoric acid solution" until "carrying out absorbance determination". 383
HG/T 2226—2000
After subtracting the absorbance of the blank solution from the absorbance of the sample, find out the manganese content in the sample from the working curve. 4.7.5 Expression of analysis results
The content of manganese (Mn) expressed as mass fraction (X.) is calculated according to formula (6): X. =
where: m.-mass of manganese in the test solution, mg; m
m × 1000
The mass of the sample in the test solution A, g. m
4.7.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.001%. 4.8 Determination of sieve residue
4.8.1 Instruments and equipment
4.8.1.1 Test sieve: R40/3 series $200mm×50mm/0.125mm and Φ200mmX50mm/0.045mm. 4.8.1.2 Brush: No. 1 wool brush.
4.8.2 Analysis steps
Weigh about 10g of sample (accurate to 0.01g), transfer it into the test sieve once or several times, wet it with water, shake the sieve while gently rinsing it with tap water until the sample no longer passes through, brush the sieve gently with a brush, rinse the brush and sieve with water until the rinse water does not contain the sample, then rinse the test sieve with 95% ethanol, transfer the sieve and the sieve residue into a constant temperature drying oven, dry it at (105±5)℃, transfer the sieve residue to a known mass of surface dish or sulfuric acid paper and weigh it (accurate to 0.0002g). 4.8.3 Expression of analysis results
The sieve residue content (X,) expressed as mass percentage is calculated according to formula (7): X,ml×100
where: mi-
the mass of the sieve residue, g;
m.---the mass of the sample,.
4.8.4 Allowable difference
. (7)
The 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: 0.003% for 125μm test sieve; 0.03% for 45um test sieve.
4.9 Determination of whiteness
4.9.1 Instruments and equipment
4.9.1.1 Whiteness meter: with standard whiteness plate and working whiteness plate, graduation value 0.2 degree. 4.9.1.2 Standard whiteness plate: must be calibrated regularly. 4.9.2 Analysis steps
Use the regularly calibrated standard whiteness plate to calibrate the working whiteness plate. The standard whiteness plate shall be sent to a professional unit for calibration every six months. Adjust the whiteness meter to the working state, place the sample evenly in the powdered blood, so that the sample surface exceeds the powdered blood by about 2 cm, cover the surface of the sample with a smooth glass plate, press the sample tightly, rotate it slightly, and remove the glass plate. Observe the surface of the sample in the horizontal direction, there should be no abnormal conditions such as unevenness, defects and scars.
Put the sample blood on the instrument table, measure the whiteness value, and read it accurately to 0.1 degree; rotate the sample blood on the instrument table 90 degrees, measure the whiteness value, and read it accurately to 0.1 degree; rotate it 90 degrees again, measure the whiteness value, and read it accurately to 0.1 degree. The extreme difference of the three readings shall not exceed 0.4 degrees. 4.9.3 Allowable difference
Take the arithmetic mean of the parallel measurement results as the measurement result. The absolute difference of the parallel measurement results shall not exceed 0.5 degrees. 4.10 Determination of water-soluble matter
4.10.1 Analysis steps
Weigh 50g of sample (accurate to 0.1g), place in a 500mL volumetric flask, add decarbonated water to the mark, and shake for 15min. Filter at 384
HG/T 2226-2000
, discard 20ml of the pre-filtrate, take 100ml of the filtrate and place it in an evaporating dish that has been weighed to a constant weight (accurate to 0.001g) at (105±2)℃, evaporate to dryness on a water bath, place the evaporator III in an oven, dry to a constant weight at (105±2)℃, and weigh (accurate to 0.001g). 4.10.2 Expression of analysis results
The water-soluble content expressed as mass fraction (X.) is calculated according to formula (8): 5ml×100
where: m
mass of water-soluble matter,;
-mass of sample, g.
4.10.3 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.02%. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of products shall not exceed 60t.
. (8)
5.3 Determine the number of sampling units according to the provisions of GB/T6678. When sampling, the sampler should be inserted obliquely from the top of the packaging bag to 3/4 of the depth of the material layer for sampling. After mixing the collected samples, they are divided into four parts to not less than 500g, and then packed into two clean, dry wide-mouth bottles with stoppers. The bottles are sealed and labeled with: manufacturer name, product name, grade, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample and the other is kept for three months for future reference. 5.4 Industrial precipitated calcium carbonate shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all industrial precipitated calcium carbonate shipped from the factory meets the requirements of this standard. 5.5 The user has the right to inspect and accept the industrial precipitated calcium carbonate received in accordance with the provisions of this standard, and the inspection and acceptance shall be carried out within two months from the date of arrival.
5.6 If one of the indicators of the inspection results does not meet the requirements of this standard, the samples shall be re-sampled from the packaging bags of twice the amount for re-inspection. If even one of the indicators of the re-inspection results does not meet the requirements of this standard, the entire batch of products shall be unqualified. 5.7 The rounded value comparison method specified in GB/T1250 shall be used to determine whether the inspection results meet the standards. 6 Marking and labeling
6.1 The packaging of industrial precipitated calcium carbonate should be firmly and clearly marked, including: manufacturer name, address, product name, trademark, grade, net content, batch number or production date, this standard number and the "wet-afraid" mark specified in GB191. 6.2 Each batch of industrial precipitated calcium carbonate leaving the factory should be accompanied by a quality certificate, including: manufacturer name, address, product name, trademark, grade, net content, batch number or production date, proof that the product quality complies with this standard and this standard number. 7 Packaging, transportation and storage
7.1 Industrial precipitated calcium carbonate is packaged in polypropylene plastic composite woven bags or other packaging, with a net content of 50kg, 40kg and 25kg per bag. 7.2 Industrial precipitated calcium carbonate should be covered during transportation to prevent it from being exposed to the sun, rain and moisture, and it must not be transported together with acids. 7.3 Industrial precipitated calcium carbonate should be stored in a cool and dry place to prevent it from being exposed to the sun, rain and moisture, and it must not be stored together with acids. 3852 Analysis steps
Use the regularly calibrated standard whiteness plate to calibrate the working whiteness plate. The standard whiteness plate is sent to a professional unit for calibration every six months. Adjust the whiteness meter to the working state, place the sample evenly in the powdered blood, so that the sample surface exceeds the powdered blood by about 2 cm, cover the surface of the sample with a smooth glass plate, press the sample tightly, rotate it slightly, and remove the glass plate. Observe the surface of the sample in the horizontal direction, there should be no abnormal conditions such as unevenness, defects and scars.
Put the sample blood on the instrument table, measure the whiteness value, and read it accurately to 0.1 degree; rotate the sample blood on the instrument table 90 degrees, measure the whiteness value, and read it accurately to 0.1 degree; rotate it 90 degrees again, measure the whiteness value, and read it accurately to 0.1 degree. The extreme difference of the three readings shall not exceed 0.4 degrees. 4.9.3 Allowable difference
Take the arithmetic mean of the parallel measurement results as the measurement result. The absolute difference of the parallel measurement results shall not exceed 0.5 degrees. 4.10 Determination of water-soluble matter
4.10.1 Analysis steps
Weigh 50g of sample (accurate to 0.1g), place in a 500mL volumetric flask, add decarbonated water to the mark, and shake for 15min. Filter at 384
HG/T 2226-2000
, discard 20ml of the pre-filtrate, take 100ml of the filtrate and place it in an evaporating dish that has been weighed to a constant weight (accurate to 0.001g) at (105±2)℃, evaporate to dryness on a water bath, place the evaporator III in an oven, dry to a constant weight at (105±2)℃, and weigh (accurate to 0.001g). 4.10.2 Expression of analysis results
The water-soluble content expressed as mass fraction (X.) is calculated according to formula (8): 5ml×100
where: m
mass of water-soluble matter,;
-mass of sample, g.
4.10.3 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.02%. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of products shall not exceed 60t.
. (8)
5.3 Determine the number of sampling units according to the provisions of GB/T6678. When sampling, the sampler should be inserted obliquely from the top of the packaging bag to 3/4 of the depth of the material layer for sampling. After mixing the collected samples, they are divided into four parts to not less than 500g, and then packed into two clean, dry wide-mouth bottles with stoppers. The bottles are sealed and labeled with: manufacturer name, product name, grade, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample and the other is kept for three months for future reference. 5.4 The industrial precipitated calcium carbonate shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all industrial precipitated calcium carbonate shipped out of the factory meets the requirements of this standard. 5.5 The user has the right to inspect and accept the industrial precipitated calcium carbonate received in accordance with the provisions of this standard, and the inspection and acceptance shall be carried out within two months from the date of arrival.
5.6 If one of the indicators of the test results does not meet the requirements of this standard, the sample shall be re-sampled from the packaging bag of twice the amount for re-testing. If even one of the indicators of the re-testing results does not meet the requirements of this standard, the entire batch of products shall be unqualified. 5.7 The rounded value comparison method specified in GB/T1250 shall be used to determine whether the test results meet the standards. 6 Marking and labeling
6.1 The packaging of industrial precipitated calcium carbonate should be firmly and clearly marked, including: manufacturer name, address, product name, trademark, grade, net content, batch number or production date, this standard number and the "wet-afraid" mark specified in GB191. 6.2 Each batch of industrial precipitated calcium carbonate leaving the factory should be accompanied by a quality certificate, including: manufacturer name, address, product name, trademark, grade, net content, batch number or production date, proof that the product quality complies with this standard and this standard number. 7 Packaging, transportation and storage
7.1 Industrial precipitated calcium carbonate is packaged in polypropylene plastic composite woven bags or other packaging, with a net content of 50kg, 40kg and 25kg per bag. 7.2 Industrial precipitated calcium carbonate should be covered during transportation to prevent sun exposure, rain and moisture, and should not be mixed with acid. 7.3 Industrial precipitated calcium carbonate should be stored in a cool and dry place to prevent sun exposure, rain and moisture, and should not be mixed with acid. 3852 Analysis steps
Use the regularly calibrated standard whiteness plate to calibrate the working whiteness plate. The standard whiteness plate is sent to a professional unit for calibration every six months. Adjust the whiteness meter to the working state, place the sample evenly in the powdered blood, so that the sample surface exceeds the powdered blood by about 2 cm, cover the surface of the sample with a smooth glass plate, press the sample tightly, rotate it slightly, and remove the glass plate. Observe the surface of the sample in the horizontal direction, there should be no abnormal conditions such as unevenness, defects and scars.
Put the sample blood on the instrument table, measure the whiteness value, and read it accurately to 0.1 degree; rotate the sample blood on the instrument table 90 degrees, measure the whiteness value, and read it accurately to 0.1 degree; rotate it 90 degrees again, measure the whiteness value, and read it accurately to 0.1 degree. The extreme difference of the three readings shall not exceed 0.4 degrees. 4.9.3 Allowable difference
Take the arithmetic mean of the parallel measurement results as the measurement result. The absolute difference of the parallel measurement results shall not exceed 0.5 degrees. 4.10 Determination of water-soluble matter
4.10.1 Analysis steps
Weigh 50g of sample (accurate to 0.1g), place in a 500mL volumetric flask, add decarbonated water to the mark, and shake for 15min. Filter at 384
HG/T 2226-2000
, discard 20ml of the pre-filtrate, take 100ml of the filtrate and place it in an evaporating dish that has been weighed to a constant weight (accurate to 0.001g) at (105±2)℃, evaporate to dryness on a water bath, place the evaporator III in an oven, dry to a constant weight at (105±2)℃, and weigh (accurate to 0.001g). 4.10.2 Expression of analysis results
The water-soluble content expressed as mass fraction (X.) is calculated according to formula (8): 5ml×100
where: m
mass of water-soluble matter,;
-mass of sample, g.
4.10.3 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.02%. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of products shall not exceed 60t.
. (8)
5.3 Determine the number of sampling units according to the provisions of GB/T6678. When sampling, the sampler should be inserted obliquely from the top of the packaging bag to 3/4 of the depth of the material layer for sampling. After mixing the collected samples, they are divided into four parts to not less than 500g, and then packed into two clean, dry wide-mouth bottles with stoppers. The bottles are sealed and labeled with: manufacturer name, product name, grade, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample and the other is kept for three months for future reference. 5.4 Industrial precipitated calcium carbonate shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all industrial precipitated calcium carbonate shipped from the factory meets the requirements of this standard. 5.5 The user has the right to inspect and accept the industrial precipitated calcium carbonate received in accordance with the provisions of this standard, and the inspection and acceptance shall be carried out within two months from the date of arrival.
5.6 If one of the indicators of the inspection results does not meet the requirements of this standard, the samples shall be re-sampled from the packaging bags of twice the amount for re-inspection. If even one of the indicators of the re-inspection results does not meet the requirements of this standard, the entire batch of products shall be unqualified. 5.7 The rounded value comparison method specified in GB/T1250 shall be used to determine whether the inspection results meet the standards. 6 Marking and labeling
6.1 The packaging of industrial precipitated calcium carbonate should be firmly and clearly marked, including: manufacturer name, address, product name, trademark, grade, net content, batch number or production date, this standard number and the "wet-afraid" mark specified in GB191. 6.2 Each batch of industrial precipitated calcium carbonate leaving the factory should be accompanied by a quality certificate, including: manufacturer name, address, product name, trademark, grade, net content, batch number or production date, proof that the product quality complies with this standard and this standard number. 7 Packaging, transportation and storage
7.1 Industrial precipitated calcium carbonate is packaged in polypropylene plastic composite woven bags or other packaging, with a net content of 50kg, 40kg and 25kg per bag. 7.2 Industrial precipitated calcium carbonate should be covered during transportation to prevent it from being exposed to the sun, rain and moisture, and it must not be transported together with acids. 7.3 Industrial precipitated calcium carbonate should be stored in a cool and dry place to prevent it from being exposed to the sun, rain and moisture, and it must not be stored together with acids. 385
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