Some standard content:
Chemical Industry Standard of the People's Republic of China
Subject Content and Scope of Application
HG/T 2327-- 92
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of industrial calcium chloride. This standard applies to industrial anhydrous calcium chloride and industrial calcium chloride dihydrate. Industrial anhydrous calcium chloride is mainly used as a desiccant; industrial calcium chloride dihydrate is mainly used in refrigeration, building materials anti-cold, petroleum and other industries. Molecular formula:
Anhydrous calcium chloride: CaCl2
Calcium chloride dihydrate: CaCl2·2H,O
Relative molecular mass:
Anhydrous calcium chloride: 111.0 (according to the international relative atomic mass in 1989) Calcium chloride dihydrate: 147.0 (according to the international relative atomic mass in 1989) 2 Reference standards
GB 601
GB 603
GB1250
GB6678
GB6682
GB8946
3 Technical requirements
3.1 Appearance
Packaging, storage and transportation Pictorial symbols
Preparation of standard solutions for titration analysis (volumetric analysis) of chemical reagents Preparation of preparations and products used in test methods of chemical reagents Methods of expressing and determining limit values General rules for sampling of chemical products
Specifications for water for laboratories
Plastic woven bags
Industrial anhydrous calcium chloride is a white block solid; industrial calcium chloride dihydrate is an off-white or slightly yellowish flake or block solid. 3.2 Industrial calcium chloride shall meet the requirements of the following table:%
Calcium chloride (CaCl2) content
Magnesium and alkali metal chloride (calculated as NaCl) content ≤Anhydrous calcium fluoride
First-class product
Qualified product approved by the Ministry of Chemical Industry of the People's Republic of China on June 1, 1992
Calcium fluoride dihydrate
First-class product
Qualified product
Implemented on September 1, 1992
Water-insoluble content Content
Controlled by Ca(OH))
Sulfate (calculated as CaSO4) content
4Test method
HG/T2327--92
Calcium chloride anhydrous
Qualified product
Calcium chloride dihydrate
Pass the test
Qualified product
The reagents and water used in this standard, unless otherwise specified, refer to analytical reagents and grade 3 water specified in GB6682. %
The standard solutions, preparations and products required in the test, unless otherwise specified, are prepared in accordance with the provisions of GB601 and GB603. 4.1 Determination of calcium fluoride (CaCl2) content
4.1.1 Method summary
Under the condition that the pH of the test solution is about 12, calcium is titrated with disodium ethylenediaminetetraacetic acid standard titration solution using calcium carboxylic acid as an indicator.
4.1.2 Reagents and materials
Triethanolamine solution: 1+2.
4.1.2.2 Sodium hydroxide (GB629) solution: 100g/L; 4.1.2.3 Disodium ethylenediaminetetraacetic acid (EDTA) (GB 1401) standard titration solution: C (Ci.H,O.N2Naz) about 0.02 mol/L; 4.1.2.4 Calcium carboxylic acid indicator: Weigh 1g of calcium carboxylic acid indicator (or sodium calcium carboxylate), mix with 100g of sodium chloride (GB1266), grind into powder, and store in a sealed container.
4.1.3 Analysis steps
4.1.3.1 Preparation of test solutionbZxz.net
Weigh about 3.5g of anhydrous calcium chloride or about 5g of dihydrate calcium chloride sample to an accuracy of 0.0002g, place in a 250mL beaker, and add water to dissolve. Transfer all to a 500ml volumetric flask, dilute to the mark with water, and shake to hook. This solution is solution A, which is used for relevant determinations. 4.1.3.2 Determination
Use a pipette to transfer 10mL of test solution A, and add water to about 50mL. Add 5mL of triethanolamine solution, 2mL of sodium hydroxide solution, and about 0.1g of calcium carboxylate indicator. Titrate with disodium ethylenediaminetetraacetic acid standard titration solution. The end point is when the solution changes from red to blue. Perform a blank test at the same time.
4.1.4 Expression of analytical results
The calcium chloride content X expressed as a mass basis percentage is calculated according to formula (1): X - (V/-V)×0.110×100
m×500
555 · c: (Vi - Vo)
. (1)
Wu:—actual concentration of disodium ethylenediaminetetraacetic acid standard titration solution, mol/L; V,—volume of disodium ethylenediaminetetraacetic acid standard titration solution consumed when titrating the test solution, mL; V.—volume of disodium ethylenediaminetetraacetic acid standard titration solution consumed in the blank test, mL; [32
m -mass of the sample, g;
0. 111 0 --
HG/T 2327—92
- The mass of calcium chloride in grams equivalent to 1.00mL of standard titration solution of disodium ethylenediaminetetraacetate [c(CiH14O.N2Na2)=1.000mol/LJ.
4.1.5 Allowable difference
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 0.2%. 4.2 Determination of magnesium and alkali metal chloride (in terms of NaCl) content 4.2.1 Summary of method
Use potassium chromate as an indicator and titrate the total chlorine with standard titration solution of silver nitrate. After subtracting the chlorine equivalent to calcium chloride, convert it into the magnesium and alkali metal chloride content in terms of sodium chloride (NaCl). 4.2.2 Reagents and materials
4.2.2.1 Nitric acid (GB626) 1+10 solution; 4.2.2.2 Sodium bicarbonate (GB640) solution: 100g/L; 4.2.2.3 Silver nitrate (GB670) standard titration solution: c (AgNO,) about 0.1mol/L; 4.2.2.4 Potassium chromate (HG3--918) solution: 50g/L. 4.2.3 Analysis steps
Pipette 10mL of test solution A into a 250mL conical flask, add 50mL of water, adjust the pH to about 6.5~~10 with nitric acid solution or sodium bicarbonate solution (check with pH test paper), add 0.7mL of potassium chromate indicator solution, and titrate with silver nitrate standard titration solution. The end point is when the solution changes from light yellow to slightly red.
4.2.4 Expression of analysis results
The content X of magnesium and alkali chloride (calculated as NaCl) expressed as mass percentage is calculated according to formula (2): X2 = c:VX 0.058 44
2.922c·V
Where:
× 100 1. 053X
The actual concentration of the standard silver nitrate titration solution, mol/L; (2)
-The volume of the standard silver nitrate titration solution consumed in the titration, mL; V
0.05844-——The mass of sodium chloride in grams equivalent to 1.00mL of the standard silver nitrate titration solution [c(AgNO,)=1.000mol/LJ;
The mass of the sample, g;
X,——The calcium chloride content measured in Article 4.1, %; 1.053-—The coefficient for converting calcium chloride (CaCl2) into sodium chloride (NaCl). 4.2.5 Allowable difference
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 0.02%. 4.3 Determination of water-insoluble matter content
4.3.1 Reagents and materials
4.3.1.1 Silver nitrate (GB670) solution: 10g/L. 4.3.2 Instruments and equipment
General laboratory instruments and equipment
4.3.2.1 Crucible filter: filter plate pore size 5~15μm. 4.3.3 Analysis steps
Weigh about 20g of sample, accurate to 0.01g, and place in a 400mL beaker. Add 250mL of water to dissolve and leave for 1h. Filter with a crucible filter that has been dried to constant weight at 105~110℃. Wash with water until there is no chloride ion (check with silver nitrate solution). Dry at 105~～110℃ to constant weight.
4.3.4 Expression of analysis results
HG/T 2327-92
The water-insoluble content X expressed as a percentage by mass is calculated according to formula (3): X
Wherein: m, —- the mass of the water-insoluble matter and the crucible filter, g; n2——the mass of the crucible filter·g;
— the mass of the sample, g.
4.3.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not be greater than 0.02%. 4.4 Determination of acidity
4.4.1 Reagents and materials
4.4.1.1 Bromothymol blue (HG3-1222) solution: 1g/L. 4.4.2 Analysis steps
(3)
Weigh 20.0±0.1g of sample, place in a 250mL beaker, add 100mL of water to dissolve. Add 2~3 drops of bromothymol blue indicator solution, the solution should not be yellow.
4.5 Determination of alkalinity
4.5.1 Summary of method
Dissolve the sample in water, add a known amount of excess hydrochloric acid standard titration solution, and boil to drive off carbon dioxide. Use bromothymol blue as the indicator and titrate with sodium hydroxide standard titration solution. 4.5.2 Reagents and materials
4.5.2.1 Hydrochloric acid (GB622) standard titration solution: c(HCI) about 0.1 mol/L. 4.5.2.2 Sodium hydroxide (GB629) standard titration solution: c(NaOH) about 0.1 mol/L. 4.5.2.3 Bromothymol blue (HG3-1222) indicator solution: 1 g/L. 4.5.3 Analysis steps
Weigh about 20 g of sample, accurate to 0.01 g, place in a 400 mL beaker, add 100 mL of water to dissolve. Add 2 to 3 drops of bromothymol blue indicator solution, use a burette to neutralize with hydrochloric acid standard titration solution and add about 5 mL excess. Boil for 2 minutes, cool, and add 2 drops of bromothymol blue indicator solution. Titrate with sodium oxide standard titration solution, and the end point is when the solution changes from yellow to blue. 4.5.4 Expression of analytical results
Alkalinity expressed as mass percentage [calculated as Ca(OH)2] X. Calculated according to formula (4): Xx (c: V/-cV) × 0.037 05 × 100m
3.705(cl - Vt - c2 : V2)
Wherein: c,~
0.037 05
actual concentration of hydrochloric acid standard titration solution, mol/L; -volume of hydrochloric acid standard titration solution consumed, mL; -actual concentration of sodium hydroxide standard titration solution, mol/L; -volume of sodium hydroxide standard titration solution consumed, mL; mass of the sample, 8;
mass of calcium hydroxide equivalent to 1.00mL hydrochloric acid standard titration solution [c(HCI) = 1.000mol/L) expressed in grams.
4.5.5 Allowable difference
The arithmetic mean of the parallel determination results shall be taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 0.02%. 4.6 Determination of sulfate content (calculated as CaSO,) 43.
4.6.1 Summary of method
HG/T 2327-92
Dissolve the sample in water and filter out the insoluble matter, add barium chloride, precipitate the sulfate ions in the filtrate, and weigh the generated barium sulfate. 4.6.2 Reagents and materials
4.6.2.1 Hydrochloric acid (GB622).
4.6.2.2 Barium fluoride (BaCl2*2H2O) (GB652) solution: 122 g/L. 4.6.2.3 Silver nitrate (GB670) solution: 10 g/L. 4.6.3 Analysis steps
Weigh about 50g of sample, accurate to 0.1g, place in a 400ml beaker, add 200ml of water to dissolve, add 2ml of hydrochloric acid, heat to boiling, cool, filter with medium-speed filter paper, wash with water 5 times, collect 10ml of filtrate and washing liquid each time in a 500ml beaker, heat to boiling, and slowly add 10ml of barium chloride solution under constant stirring; continue boiling for 15min, cool and place for 4h (or keep warm in a boiling water bath for 2h). Filter with slow quantitative filter paper at room temperature, wash the precipitate with warm water until there is no chloride ion (check with silver nitrate solution). Transfer the precipitate together with the filter paper to a porcelain crucible that has been constant weight at 800±20℃, dry, ashed, and burn to constant weight at 800±20℃. 4.6.4 Expression of analysis results
Sulfate content expressed as mass percentage [calculated as CaSO,] X. Calculate according to formula (5): Xs = (ml-mz) × 0.5833 × 100m
58.33(m m2)
Wherein: m,—mass of barium sulfate and porcelain, g; m2——mass of porcelain crucible, g;
m-mass of sample, g,
0.5833—coefficient for converting barium sulfate into calcium sulfate. 4.6.5 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 0.03%. 5 Inspection rules
5.1 Industrial calcium chloride 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 calcium chloride shipped from the factory meets the requirements of this standard. Each batch of products leaving the factory shall be accompanied by a quality certificate, which shall include: manufacturer name, product name, grade, net weight, batch number or production date, proof that product quality complies with this standard and the number of this standard. 5.2 The user has the right to inspect and accept the industrial calcium chloride received in accordance with the provisions of this standard. The inspection and acceptance shall be carried out within one month from the date of arrival of the goods.
5.3 During normal production, the sulfate content shall be measured once a month. 5.4 Each batch of products shall not exceed 150t.
5.5 The number of sampling units shall be determined in accordance with Article 6.6 of GB6678. When sampling, representative samples shall be taken from the upper, middle and lower parts of the package and mixed. Use the quartering method to reduce to no less than 500g, and divide into two clean and dry wide-mouth bottles and seal them; label the bottles with the manufacturer name, product name, grade, batch number, sampling date and the name of the sampler; one bottle shall be used for inspection and the other bottle shall be kept for 3 months for future reference. 5.6 If one of the indicators in the test results does not meet the requirements of this standard, samples should be taken from twice the amount of packaging for re-verification. If even one indicator in the verification results does not meet the requirements of this standard, the entire batch of products cannot be accepted. 5.7 When the supply and demand parties have objections to the product quality, they shall be handled in accordance with the provisions of the "Interim Measures for National Product Quality Arbitration Inspection". 5.8 This standard adopts the rounded value comparison method specified in GB1250 to determine whether the test results meet the standard. 6 Marking, packaging, transportation and storage
6.1 The package should be firmly and clearly marked, including: manufacturer name, product name, trademark, grade, net weight, this standard number and the mark specified in 435
GB191 6\ Afraid of moisture".
6.2 Anhydrous calcium chloride is packaged in two ways. HG/T2327-92
6.2.1 Bag packaging: The inner packaging is a polyethylene plastic film bag with a specification size of 1100mm×550mm and a thickness of 0.2mm; the outer packaging is a plastic woven bag with a specification size of 1000mm×500m m, its performance and inspection methods shall comply with the provisions of GB8946, Type C. Net weight of each bag is 50kg.
The inner bag is glued, or tied manually with vinyl rope or other rope of equivalent quality; the outer bag is folded at a distance of not less than 30mm from the edge of the bag. The edge is sewn with vinyl thread or other thread of equivalent quality at a distance of not less than 15mm from the edge of the bag, with a stitch length of 10 to 20mm, neat stitches, uniform stitch length, and no leaking or skipping.
6.2.2 Barrel: The inner packaging is made of polyethylene plastic film bags, with specifications and dimensions: 1100mm×550mm, and a thickness of 0.2mm; the outer packaging is made of asphalt-coated hard Fiberboard barrel. Specification size: $400mm×540mm, thickness is 5mm, net weight of each barrel is 50kg. The inner bag is glued or tied manually with nylon rope or other ropes of equivalent quality; the outer barrel cover is nailed with a cross wooden frame.
6.3- Two packaging methods for calcium fluoride hydrate 6.3.1 Flake calcium fluoride dihydrate is double-layered, and the inner packaging is a polyethylene plastic film bag. The inner bag is 10mm longer and 5mm wider than the outer bag. The outer packaging is a plastic woven bag, and its performance and inspection methods should comply with the provisions of GB8947 Type C (or Type B); each bag has a net weight of 50kg or 25kg .
The inner bag is glued or tied manually with vinyl rope or other rope of equivalent quality; the outer bag is folded at a distance of not less than 30mm from the bag edge, and the mouth is sewn with vinyl thread or other thread of equivalent quality at a distance of not less than 15mm from the bag edge, with a stitch length of 8 to 15mm, neat stitches, uniform stitch length, and no leaking or skipping.
6.3.2 Block calcium chloride dihydrate is packaged in a middle-opening iron barrel, and its performance and inspection methods shall comply with relevant regulations. The net weight of each barrel is 200kg. The iron barrel is sealed with a pressure cap, which is pressed firmly with a pressure capping pliers, and there is no leakage. 6.4 This product should be protected from rain and moisture during transportation. 6.5 This product should be stored in a cool and dry place, away from rain and moisture. Additional remarks:
This standard was proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Tianjin Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by Tianjin Alkali Factory and Tianjin Chemical Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Liu Youruo, Jia Yurong, Huang Jiapeng and Zhao Duanpin. This standard refers to the British national standard BS3587--1963 (confirmed in 1986) "Specifications for technical grade calcium chloride". 436
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