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Record number: 10076-2002bzxz.net
HG 3255-2001
Chapter 5, Chapter 6, Chapter 7 and Chapter 8 of this standard are mandatory, and the rest are recommended. This standard is a revision of the mandatory chemical industry standard HG3255-1990 "Industrial Sodium Cyanide". The main technical differences between this standard and HG3255--1990 are as follows: - The index of solid sodium cyanide content for superior products is adjusted to 98.0%, and the index of qualified products is adjusted to 87.0%; the three grades of sodium carbonate content are adjusted to 0.5%, 2.0% and 3.0% respectively. The silver nitrate method is added to the determination of sodium cyanide content, and the silver nitrate method is used as the arbitration method. The full text of the standard is changed from mandatory to mandatory. This standard will replace HG3255--1990 from the date of implementation. Appendix A of this standard is a prompt appendix.
This standard was proposed by the Policy and Regulations Department of the former State Administration of Petroleum and Chemical Industry. This standard is under the jurisdiction of the Inorganic Chemical Industry Branch of the National Technical Committee for Chemical Standardization. The main drafting units of this standard are: Tianjin Chemical Research and Design Institute, Sino-foreign joint venture Anhui Anqing Shuguang Chemical Co., Ltd., Tianjin Huasheng Chemical Co., Ltd., Shanghai Petrochemical Co., Ltd., and Fushun Shunhua Chemical Enterprise Co., Ltd. of Liaoning Province. The drafting unit of this standard is: Hebei Chengxin Co., Ltd. The main drafters of this standard are: Guo Fengxin, Wang Lin, Zong Shiling, Liu Youruo, Ding Weifeng, and Jiang Yong. This standard was first issued in 1990, and was converted from a professional standard to a mandatory chemical industry standard in 1999, and was renumbered as HG 32551990.
This standard is entrusted to the Inorganic Chemical Industry Branch of the National Technical Committee for Chemical Standardization for interpretation. 1023
1 Scope
Chemical Industry Standard of the People's Republic of China
Industrial Sodium Cyanide
Sodium Cyanide for Industrial UseHG3255--2001
Replaces HG32551990
This standard specifies the requirements, test methods, inspection rules, marking, labeling, packaging, transportation, storage and safety of industrial sodium cyanide. This standard applies to industrial solid sodium cyanide and sodium cyanide solution. The product is mainly used in chemical industry, electroplating, metallurgy, mineral processing and as a raw material for the pharmaceutical industry.
Molecular formula: NaCN
Relative molecular mass: 49.01 (according to the 1999 international relative atomic mass) 2
Cited 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 valid. All standards are subject to revision and parties using this standard should investigate the possibility of using the most recent versions of the following standards. GB190-1990 Dangerous Goods Packaging Mark
GB/T601-1988 Preparation of standard solutions for titration analysis (volumetric analysis) of chemical reagents GB/T603--1988 Preparation of preparations and products used in test methods for chemical reagents (neqIS()6353-1:1982) GB/T1250--1989 Expression and determination methods of limit values GB/T 6678—1986
General rules for sampling of chemical products
GB/T 6680
General rules for sampling of liquid chemical products
GB/T 6682—1992
3 Requirements
3.1 Appearance
Specifications and test methods for water for analytical laboratories (eqv1SO3696:1987) Solid sodium cyanide should be white or slightly colored blocks or crystalline particles. Sodium cyanide solution should be a colorless or light yellow transparent aqueous solution. 3.2 Industrial sodium cyanide should meet the requirements of Table 1. Table 1 Requirements
Mass fraction of sodium cyanide (NaCN)
Mass fraction of sodium hydroxide (.Na()H)
Mass fraction of sodium carbonate (VaaCO))
Mass fraction of water-insoluble matter
Superior product
First-class product
Qualified product
Note: For the product sodium cyanide solution, when the ambient temperature is below 0℃, its sodium cyanide content can be determined by negotiation between the supply and demand parties. Approved by the State Economic and Trade Commission on January 24, 2002 1024
First-class product
Qualified product
Implemented on July 1, 2002
4 Test methods
HG 3255--2001
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, preparations and products used in the test, unless otherwise specified, are prepared in accordance with the provisions of GB/T601 and GB/T603.
Warning: Sodium cyanide is a highly toxic substance. Sampling and analysis operations should be carried out in strict accordance with the safety requirements of this standard. The waste liquid after analysis should be handled in accordance with the requirements of Appendix A. The hydrochloric acid used in the analysis is corrosive. Users should be careful to avoid splashing on the skin. If splashed on the skin, rinse immediately with plenty of water and seek timely treatment for severe cases. 4.1 Determination of sodium cyanide content
4.1.1 Silver nitrate method (arbitration method)
4.1.1.1 Summary of the method
In an ammonia medium, silver ions and cyanide ions form a complex, and excess silver ions and potassium iodide form a precipitate, indicating the titration end point. Calculate the content of sodium cyanide based on the consumption of the silver nitrate standard titration solution. 4.1.1.2 Reagents and materials
a) Ammonia solution: 2+3.
b) Silver nitrate standard titration solution: c (AgNO,) about 0.05 mol/L. c) Potassium iodide solution: 50 g/L.
4.1.1.3 Preparation of test solution
Weigh about 2g2.5g of solid sample or 7g~8g of solution sample (accurate to 0.0002g). Place in a beaker, dissolve the sample in water, transfer all to a 500mL volumetric flask, dilute to scale with water, and shake well. This solution is test solution A, used for the determination of sodium cyanide content, sodium hydroxide content, and sodium carbonate content.
4.1.1.4 Analysis steps
Use a pipette to transfer 25mL of test solution A, place in a conical flask, add 75mL of water, 1mL of ammonia solution and 1mL of potassium iodide solution, and titrate with silver nitrate standard titration solution until turbidity just appears as the endpoint. 4.1.1.5 Expression of analysis results
The sodium cyanide (NaCN) content (X,) expressed as mass fraction is calculated according to formula (1): X = Yc×0.098 02 ×100 = I
m×500
196. 04 XV c
Where.: Volume of standard silver nitrate solution consumed by titrating the test solution, mL.--Actual concentration of standard silver nitrate solution, mol/L; mMass of sample, g;
(1)
0.09802---Mass of sodium cyanide expressed in grams equivalent to 1.00mL standard silver nitrate solution Ec (AgNOs) = 1.000mol/LJ.
4.1.1.6 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 0.2%. 4.1.2 Nickel nitrate method
4.1.2.1 Method summary
In an ammonia medium, nickel ions and cyanide ions form a complex, and excess nickel ions and diacetyl form a bright red flocculent precipitate, indicating the titration end point. The content of sodium cyanide is calculated based on the consumption of nickel nitrate solution and the conversion factor of the standard silver nitrate titration solution and the concentration of the standard silver nitrate titration solution.
4.1.2.2 Reagents and materials
a) Ammonia solution: 2+3.
h) Potassium iodide solution: 50g/l.
HG 3255—2001
c) Standard silver nitrate titration solution: c (AgN,) about 0.05mol/l. d) Nickel nitrate solution: cL-
-Ni(NO,)2] is about 0. 05 mol/L.
Preparation: Weigh 7.27g nickel nitrate [Ni(NO,)2·6HzO] (accurate to 0.01g), dissolve in 1000ml water, and shake well. Conversion coefficient of nickel nitrate solution to silver nitrate standard titration solution: Use a pipette to transfer 25mL of test solution A, place it in a conical flask, add 75mL of water and 6-8 drops of diacetyl ammonia solution, and titrate with nickel nitrate solution. When the solution turns bright yellow and bright red flocculent precipitate appears under continuous shaking, it is the end point; use a pipette to transfer 25mL of test solution A, place it in another conical flask, add 75mL of water, 1ml. ammonia solution and 1mL potassium iodide solution, and titrate with silver nitrate standard titration solution until turbidity just appears as the end point. Conversion coefficient (K) of nickel nitrate solution to silver nitrate standard titration solution,Calculate according to formula (2): K
-the volume of nickel nitrate solution consumed in titration, mL; where: V→
-the volume of standard silver nitrate solution consumed in titration, mL. The result should be expressed to four decimal places, and the average of three parallel determination results is taken as the value of the conversion factor (K). e) Diacetyl ammonia aqueous solution: 5 g/L.
4.1.2.3 Analysis steps
Use a pipette to transfer 25 mL of test solution A, place it in a conical flask, add 75 mL of water and 6 to 8 drops of diacetyl nitrogen aqueous solution, and titrate with nickel nitrate solution. When the solution turns bright yellow and a bright red flocculent precipitate appears under continuous shaking, the end point is reached. 4.1.2.4 Expression of analysis results
The sodium cyanide (NaCN) content (X,) expressed as mass fraction is calculated according to formula (3): Xx = VKc×0. 098 02 ×100 = 196. 04 ×VKc25
Wherein: V.
-the volume of nickel nitrate solution consumed by the titration test solution, mL; -the actual concentration of the silver nitrate standard titration solution, mol/L; K is the conversion factor of nickel nitrate solution to the silver nitrate standard titration solution; m-the mass of the sample, g;
0.09802-the mass of sodium cyanide expressed in grams equivalent to 1.00 mL of the silver nitrate standard titration solution [c (AgNO:) = 1.000 mol/L].
4.1.2.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference between the parallel determination results shall not exceed 0.2%. 4.2 Determination of sodium hydroxide content
4.2.1 Method summary
Use silver nitrate solution (or nickel nitrate solution) to mask cyanide ions, use barium chloride to precipitate carbonate ions, use phenolic acid as an indicator, and use hydrochloric acid standard titration solution to titrate the sodium hydroxide content. 4.2.2 Reagents and materials
4.2.2.1 Barium chloride solution: 100g/L.
4.2.2.2 Hydrochloric acid standard titration solution: c(HCI) about 0.05mol/L. 4.2.2.3 Phenol indicator: 10g/L.
4.2.3 Instruments and equipment
Microburette: the graduation value is 0.02mL. 4.2.4 Analysis steps
Use a pipette to transfer 25 mL of test solution A into a conical flask and add 50 mL of water. Add twice the volume of silver nitrate standard titration solution consumed during titration according to 4.1.1.4, shake vigorously, filter with fast filter paper, rinse with 10 mL to 15 mL of water 2 to 31026
HG 3255—2001
times, collect the filtrate in a conical flask (or add the same volume of nickel nitrate solution consumed during titration according to 4.1.2.3 and an excess of 0.1 mL to 0.2 mL, shake vigorously). Add 10 mL of barium chloride solution, shake thoroughly for 1 to 2 minutes and then let stand for 15 minutes. Add 2 drops of phenol indicator and titrate with hydrochloric acid standard titration solution until the red color disappears. 4.2.5 Expression of analysis results
The content of sodium hydroxide (NaOH) expressed as mass fraction (X:) is calculated according to formula (4): X. = Ve × 0. 040 00 × 100 = 80. 00 Vc25
m × 500
Wherein: V-
The volume of hydrochloric acid standard titration solution consumed by the titration test solution, mL; the actual concentration of hydrochloric acid standard titration solution, mol/I; the mass of the sample, g;
(4)
The mass of sodium hydroxide expressed in grams equivalent to 1.00mL hydrochloric acid standard titration solution [c(HCI) = 1.000 mol/L].
4.2.6 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 0.05% for superior products; and not exceed 0.1% for first-class products and qualified products.
4.3 Determination of sodium carbonate content
4.3.1 Method summary
Use silver nitrate solution (or nickel nitrate solution) to mask cyanide ions, use phenolphthalein as an indicator, and titrate the total alkali content with hydrochloric acid standard titration solution, minus the sodium hydroxide content.
4.3.2 Reagents and materials
4.3.2.1 Hydrochloric acid standard titration solution: c(HCl) about 0.05 mol/L. 4.3.2.2 Phenolic acid indicator: 10 g/1.
4.3.3 Instruments and equipment
Microburette: graduation value is 0.02 mL. 4.3.4 Analysis steps
Use a pipette to transfer 25 ml of test solution A into a conical flask and add 50 mL of water. Add twice the volume of silver nitrate standard titration solution consumed during titration according to 4.1.1.4, shake vigorously, filter with fast filter paper, rinse with 10mL~15mL water 2~~3 times, collect the filtrate in a conical flask (or add the same volume of nickel nitrate solution consumed during titration according to 4.1.2.3 with an excess of 0.1mL~0.2mL, shake vigorously). Add 2 drops of phenolic acid indicator and titrate with hydrochloric acid standard titration solution until the red color disappears. 4.3.5 Expression of analytical results
The sodium carbonate (NazCO) content (X4) expressed as mass fraction is calculated according to formula (5): X = 2(V-Vo)cX0. 05299 × 100m 212. 0(V-Vcm×500
Wherein: V-
the volume of hydrochloric acid standard titration solution consumed by the titration test solution, mL; m
-the volume of hydrochloric acid standard titration solution consumed by the titration test solution in 4.2.4, mL; the actual concentration of the hydrochloric acid standard titration solution, mol/L; the mass of the sample, g,
and 1.00ml. Hydrochloric acid standard titration solution [c(HC1)=1.000mol/L ] is equivalent to the mass of sodium carbonate expressed in grams.
4.3.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results is not more than 0.05% for superior products; not more than 0.1% for first-class products and qualified products.
4.4 Determination of moisture
4.4.1 Instruments and equipment
4.4.1.1 Weighing bottle: $45mm×25mm
HG 3255--2001
4.4.1.2 Electric constant temperature drying oven: can control the temperature at 105℃~110℃. 4.4.2 Analysis steps
Use a weighing bottle with constant weight in advance to weigh 3g~5g of solid sample (accurate to 0.0002g), move it into the electric constant temperature drying oven, open the lid, and dry it at 105℃~110℃ for 2.5h. Take it out, place it in a desiccator, cool it for 30min, weigh it (accurate to 0 .0002g). 4.4.3 Expression of analysis results
The moisture content (X.) expressed as mass fraction is calculated according to formula (6): X, = m = m2 × 100
Where: ... — the mass of the weighing bottle and the sample before drying, .; m2-the mass of the weighing bottle and the sample after drying, g; m-. — the mass of the sample, g.
4.4.4 Allowable difference
The arithmetic mean of the parallel determination results is taken as the test result. The absolute difference between the parallel determination results shall not exceed 0.1%. 4.5 Determination of water-insoluble matter content
4.5.1 Reagents and materials
Silver nitrate solution: 50g/L.
4.5.2 Instruments and equipment
4.5.2.1 Glass sand: filter plate pore size 5μm~15μm. 4.5.2.2 Electric constant temperature drying oven: can control the temperature at 105℃~110℃. 4.5.3 Analysis steps
Use a weighing bottle to weigh about 5g of solid sample (accurate to 0.01g), place it in a beaker, and add 10ml~12ml of hot water (50℃~60℃). Filter it with a glass sand crucible that has been kept constant weight at 105℃~~110℃ in advance, and wash it with hot water until the filtrate does not contain cyanide ions (check with silver nitrate solution). Move the glass sand crucible together with the insoluble matter into an electric constant temperature drying oven and dry it at 105℃~110℃ to constant weight. 4.5.4 Expression of analysis results
The water insoluble matter (X2) expressed as mass fraction is calculated according to formula (7): Xs=m=m2×100
Where: m2—mass of glass sand crucible together with insoluble matter, g; m2—mass of glass sand, g;
m—mass of sample, g.
4.5.5 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 0.01% for superior products; and shall not exceed 0.05% for first-class products and qualified products.
5 Inspection rules
5.1 This standard adopts type inspection and routine inspection. Type inspection: All index items in the requirements are type inspection items. Under normal circumstances, type inspection shall be carried out at least once every three months.
Routine inspection: Sodium cyanide content, sodium hydroxide content, sodium carbonate content, and water content are routine inspection items and shall be inspected batch by batch. 5.2 Each batch of solid sodium cyanide shall not exceed 20t; each batch of sodium cyanide solution shall not exceed 200t. 1028
HG3255—2001
5.3 The number of sampling units for solid sodium cyanide shall be determined in accordance with the provisions of G13/T6678. When sampling, the sampler shall be inserted obliquely from the top of the packaging barrel to 3/4 of the depth of the material layer for sampling. Take representative samples of block products. After mixing the collected samples, reduce them to not less than 100g by quartering method.
The sodium cyanide solution shall be sampled in accordance with the provisions of (Gi3/T6680) from the discharge port of the tank truck, and the sampling volume shall not exceed 100ml. The collected samples shall be divided into two clean and dry plastic bottles or wide-mouth bottles with ground stoppers and sealed. Labels shall be affixed to the bottles, indicating the manufacturer's name, product name, grade, batch number, sampling date and the name of the sampler. One bottle shall be used as a laboratory sample and the other bottle shall be kept for reference. The storage period of solid sodium cyanide samples is one month, and the storage period of sodium cyanide liquid samples is 15 days. 5.4 Industrial sodium cyanide 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 each batch of products leaving the factory meets the requirements of this standard.
5.5 The user has the right to inspect the industrial cyanide received in accordance with the provisions of this standard. The sodium cyanide products shall be inspected and accepted within one month after the arrival of the goods.
5.6 If one of the test results does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-testing. Even if only one indicator of the re-test result 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 (I31250) shall be used to determine whether the test results meet the standards. 6 Markings and labels
6.1 The packaging of industrial sodium cyanide shall have firm and clear markings, including the manufacturer's name, address, product name, trademark, grade, net content, batch number or production date, this standard number and the "highly toxic" mark specified in (GB190. 6.2 Each batch of industrial sodium cyanide leaving the factory shall be accompanied by a quality certificate. The content shall include the manufacturer's Name, factory address, product name, trademark, grade, net content, batch number or production date, proof that the product quality complies with this standard and the number of this standard. 7 Packaging, transportation, purchase and storage
7.1 Industrial sodium cyanide solution should be stored in special steel storage tanks or tank cars, and industrial solid sodium cyanide should be packaged in sealed iron barrels lined with polyethylene plastic film bags. The iron sheet is 0.8 (or 0.75) mm thick, and the net content of each barrel is 25kg or 50kg. 7.2 For the packaging of industrial solid sodium cyanide, the inner bag is tied with vinyl rope or other rope of equivalent quality, or sealed with other equivalent methods. 7.3 The production, use and transportation of industrial sodium cyanide shall comply with the provisions of the "Regulations on the Management of Dangerous Goods" of the Ministry of Public Security of the People's Republic of China and the "Regulations on the Management of Railway Dangerous Goods" of the Ministry of Railways of the People's Republic of China. 7.4 Industrial solid sodium cyanide should be stored in a special lockable warehouse, and sodium cyanide solution should be stored in a special lockable storage tank and tank garage to avoid contact or co-storage with acids, nitrates, and nitrites. 7.5 Storage tanks, tank trucks, valves, and pumps of sodium cyanide solution should be checked regularly to prevent leakage. 8 Safety
8.1 To avoid direct contact with sodium cyanide, operators should wear rubber gloves and glasses, and wear protective tools such as aprons and rubber shoes: sampling personnel should also have corresponding protective measures.
8.2 In order to avoid inhaling gas containing hydrocyanic acid, a gas mask should be worn when necessary. 8.3 Avoid contact with acid. If there is sodium cyanide dust or solution splashing, flush with a large amount of water, and the flushing water should be treated before it can be released.
8.4 Ventilation equipment should be installed in places where sodium cyanide is used for a long time. 8.5 Workers in production workshops, laboratories and sampling stations are not allowed to work with any unhealed wounds, and work can only be carried out when there are more than two people.
8.6 In places where sodium cyanide is present, such as production workshops and laboratories, eating and smoking are not allowed. After work, you must take a shower and change clothes. 8.7 For units that handle sewage, the waste liquid after the test should be collected in a special container and treated according to the provisions of Appendix A (Suggestive Appendix). 1029
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Appendix A
(Suggestive Appendix)
Treatment of cyanide waste liquid
In order to prevent the pollution of cyanide waste liquid, all cyanide waste liquid should be treated before discharge. A1
Method Summary
In alkaline medium, hypochlorite is used as an oxidant to oxidize and decompose cyanide ions into non-toxic nitrogen and carbon dioxide. Treatment steps
Collect the waste liquid in a container of about 10L, add 40% sodium hydroxide solution until the pH value of the waste liquid is greater than 8.5 (check with pH test paper). Place in a fume hood, add 250g bleaching powder, stir thoroughly, and leave for 12 hours before draining. The reagents used in the above operation are all industrial grade. 10303 Avoid contact with acid. If there is sodium cyanide dust or solution splashing, flush with a large amount of water. The flushing water should be treated before it can be released.
8.4 Ventilation equipment should be installed in places where sodium cyanide is used for a long time. 8.5 Workers in production workshops, laboratories, sampling and other work positions shall not bring any unhealed wounds to work, and work can only be carried out when there are more than two people.
8.6 In places where sodium cyanide is present, such as production workshops and laboratories, eating and smoking are not allowed. After work, you must take a shower and change clothes. 8.7 For units that handle sewage measures, the waste liquid after the test should be collected in a special container and treated in accordance with the provisions of Appendix A (Suggested Appendix). 1029
HG3255—2001
Appendix A
(Suggestive Appendix)
Treatment of cyanide-containing waste liquid
In order to prevent the pollution of cyanide-containing waste liquid, all cyanide-containing waste liquid should be treated before discharge. A1
Method Summary
In an alkaline medium, hypochlorite is used as an oxidant to oxidize and decompose cyanide ions into non-toxic nitrogen and carbon dioxide. Treatment steps
Collect the waste liquid in a container of about 10L, add 40% sodium hydroxide solution until the pH value of the waste liquid is greater than 8.5 (check with pH test paper). Place in a fume hood, add 250g of bleaching powder, stir thoroughly, and discharge after leaving for 12 hours. The reagents used in the above operations are all industrial grade. 10303 Avoid contact with acid. If there is sodium cyanide dust or solution splashing, flush with a large amount of water. The flushing water should be treated before it can be released.
8.4 Ventilation equipment should be installed in places where sodium cyanide is used for a long time. 8.5 Workers in production workshops, laboratories, sampling and other work positions shall not bring any unhealed wounds to work, and work can only be carried out when there are more than two people.
8.6 In places where sodium cyanide is present, such as production workshops and laboratories, eating and smoking are not allowed. After work, you must take a shower and change clothes. 8.7 For units that handle sewage measures, the waste liquid after the test should be collected in a special container and treated in accordance with the provisions of Appendix A (Suggested Appendix). 1029
HG3255—2001
Appendix A
(Suggestive Appendix)
Treatment of cyanide-containing waste liquid
In order to prevent the pollution of cyanide-containing waste liquid, all cyanide-containing waste liquid should be treated before discharge. A1
Method Summary
In an alkaline medium, hypochlorite is used as an oxidant to oxidize and decompose cyanide ions into non-toxic nitrogen and carbon dioxide. Treatment steps
Collect the waste liquid in a container of about 10L, add 40% sodium hydroxide solution until the pH value of the waste liquid is greater than 8.5 (check with pH test paper). Place in a fume hood, add 250g of bleaching powder, stir thoroughly, and discharge after leaving for 12 hours. The reagents used in the above operations are all industrial grade. 1030
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