HG/T 3688-2025 Flaky and high quality potassium hydroxide English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
Professional Standard of the People’s Republic of China
HG/T 3688-2025
Flaky and high quality potassium hydroxide
高品质片状氢氧化钾
(English Translation)
Issue date: 1996-05-02 Implementation date: 1996-09-01
Issued by the Ministry of Chemical Industry of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Molecular formula and relative molecular mass
5 Classification
6 Requirements
7 Test methods
8 Inspection rules
9 Marking, labelling and accompanying documents
10 Packaging, transportation and storage
High-quality flaky potassium hydroxide
Warning: In accordance with the provisions of Clause 6 of GB 12268-2012, this product belongs to Class 8 corrosive substances. Care shall be taken during handling. Personnel using this document should have practical working experience in a regular laboratory. This document does not purport to address all possible safety issues. It is the responsibility of the user to take appropriate safety and health measures and to ensure compliance with the conditions prescribed by relevant national regulations.
1 Scope
This document specifies the classification, requirements, test methods, inspection rules, marking, labelling and accompanying documents, packaging, transportation and storage of high-quality flaky potassium hydroxide.
This document is applicable to high-quality flaky potassium hydroxide obtained by ion-exchange membrane electrolysis of refined potassium chloride.
Note: This product is mainly used in high-grade detergents and cosmetics, disproportionated rosin potassium soap and various potassium salts, pharmaceutical intermediates, synthetic rubber, ABS resin and natural rubber latex, fermentation, paper sizing agents, pesticide manufacturing, etc.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB 190, Packing symbol of dangerous goods
GB/T 191-2008, Packaging — Pictorial marking for handling of goods
GB/T 325.2, Packaging containers — Steel drums — Part 2: Removable head (open head) drums with a minimum total capacity of 208 L, 210 L and 216.5 L
GB/T 2306-2008, Chemical reagent — Potassium hydroxide
GB/T 3049-2006, Chemical products for industrial use — General method for determination of iron content — 1,10-Phenanthroline spectrophotometric method
GB/T 3050-2000, Inorganic chemical products for industrial use — General method for determination of chloride content — Potentiometric titration method
GB/T 6679, General rules for sampling solid chemical products
GB/T 6682-2008, Water for analytical laboratory use — Specification and test methods
GB/T 8170, Rules of rounding off for numerical values and expression and judgement of limiting values
GB 12268-2012, List of dangerous goods
GB 12463, General technical specifications for transport packages of dangerous goods
GB 15603, General rules for storage of common dangerous chemicals
HG/T 3696.1, Inorganic chemicals for industrial use — Preparations of standard and reagent solutions for chemical analysis — Part 1: Preparations of standard volumetric solutions
HG/T 3696.2, Inorganic chemicals for industrial use — Preparations of standard and reagent solutions for chemical analysis — Part 2: Preparations of impurity standard solutions
HG/T 3696.3, Inorganic chemicals for industrial use — Preparations of standard and reagent solutions for chemical analysis — Part 3: Preparations of reagent solutions and indicator solutions
UN Model Regulations, Recommendations on the Transport of Dangerous Goods
3 Terms and definitions
No terms and definitions are required to be defined in this document.
4 Molecular formula and relative molecular mass
Molecular formula: KOH
Relative molecular mass: 56.10 (based on 2022 international relative atomic masses)
5 Classification
High-quality flaky potassium hydroxide is classified into the following two types:
— Type I: 95 % specification, products with potassium hydroxide content of 95 % and above.
— Type II: 90 % specification, products with potassium hydroxide content of 90 % and above but below 95 %.
6 Requirements
6.1 Appearance: White flakes.
6.2 High-quality flaky potassium hydroxide tested in accordance with the test methods specified in this document shall comply with Table 1.
7 Test methods
7.1 General provisions
Unless otherwise specified, the reagents and water used in this document shall be of analytical grade and Grade 3 water in accordance with Table 1 of GB/T 6682-2008.
Unless otherwise specified, the standard volumetric solutions, impurity standard solutions, reagent solutions and indicator solutions used in the tests shall be prepared in accordance with HG/T 3696.1, HG/T 3696.2 and HG/T 3696.3.
7.2 Appearance inspection
Under natural light, visually inspect the appearance on a watch glass or white porcelain plate with a white background.
7.3 Determination of potassium hydroxide and potassium carbonate content
7.3.1 Principle
Barium chloride reacts with potassium carbonate in the test solution to form barium carbonate precipitate. Using phenolphthalein as indicator, the potassium hydroxide is titrated with hydrochloric acid standard volumetric solution. Then an excess of hydrochloric acid standard volumetric solution is added to react with barium carbonate, and the remaining hydrochloric acid standard volumetric solution is titrated with sodium hydroxide standard volumetric solution. The contents of potassium hydroxide and potassium carbonate are calculated.
7.3.2 Reagents or materials
7.3.2.1 Barium chloride solution: 100 g/L. Before use, add phenolphthalein indicator solution (10 g/L) and adjust to pink colour with 0.1 mol/L sodium hydroxide solution.
7.3.2.2 Hydrochloric acid standard volumetric solution I: c(HCl) ≈ 1 mol/L.
7.3.2.3 Hydrochloric acid standard volumetric solution II: c(HCl) ≈ 0.1 mol/L.
7.3.2.4 Sodium hydroxide standard volumetric solution: c(NaOH) ≈ 0.1 mol/L.
7.3.2.5 Carbon dioxide-free water.
7.3.2.6 Phenolphthalein indicator solution: 10 g/L.
7.3.3 Test procedure
7.3.3.1 Preparation of test solution A
Using a dried weighing bottle, quickly weigh approximately 40 g of the specimen (accurate to 0.01 g) and place in a 250 mL beaker. Add an appropriate amount of carbon dioxide-free water to dissolve. After cooling to room temperature, transfer completely to a 1000 mL volumetric flask, dilute to the mark with carbon dioxide-free water, and shake well. Immediately transfer to a clean, dry 1000 mL plastic bottle for storage. This solution is test solution A, used for the determination of potassium hydroxide content, potassium carbonate content, chloride content (potentiometric titration method), iron content (inductively coupled plasma optical emission spectrometry), and sodium content.
7.3.3.2 Test
Using a pipette, transfer 50 mL of test solution A into a 250 mL conical flask. Add 10 mL of barium chloride solution and shake quickly. Add 2 to 3 drops of phenolphthalein indicator solution, and immediately titrate with hydrochloric acid standard volumetric solution I until the solution becomes colourless. Record the volume of hydrochloric acid standard volumetric solution I consumed as V₁.
Standard
HG/T 3688-2025 Flaky and high quality potassium hydroxide (English)
HG/T 3688-2025 Flaky and high quality potassium hydroxide English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
Professional Standard of the People’s Republic of China
HG/T 3688-2025
Flaky and high quality potassium hydroxide
高品质片状氢氧化钾
(English Translation)
Issue date: 1996-05-02 Implementation date: 1996-09-01
Issued by the Ministry of Chemical Industry of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Molecular formula and relative molecular mass
5 Classification
6 Requirements
7 Test methods
8 Inspection rules
9 Marking, labelling and accompanying documents
10 Packaging, transportation and storage
High-quality flaky potassium hydroxide
Warning: In accordance with the provisions of Clause 6 of GB 12268-2012, this product belongs to Class 8 corrosive substances. Care shall be taken during handling. Personnel using this document should have practical working experience in a regular laboratory. This document does not purport to address all possible safety issues. It is the responsibility of the user to take appropriate safety and health measures and to ensure compliance with the conditions prescribed by relevant national regulations.
1 Scope
This document specifies the classification, requirements, test methods, inspection rules, marking, labelling and accompanying documents, packaging, transportation and storage of high-quality flaky potassium hydroxide.
This document is applicable to high-quality flaky potassium hydroxide obtained by ion-exchange membrane electrolysis of refined potassium chloride.
Note: This product is mainly used in high-grade detergents and cosmetics, disproportionated rosin potassium soap and various potassium salts, pharmaceutical intermediates, synthetic rubber, ABS resin and natural rubber latex, fermentation, paper sizing agents, pesticide manufacturing, etc.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB 190, Packing symbol of dangerous goods
GB/T 191-2008, Packaging — Pictorial marking for handling of goods
GB/T 325.2, Packaging containers — Steel drums — Part 2: Removable head (open head) drums with a minimum total capacity of 208 L, 210 L and 216.5 L
GB/T 2306-2008, Chemical reagent — Potassium hydroxide
GB/T 3049-2006, Chemical products for industrial use — General method for determination of iron content — 1,10-Phenanthroline spectrophotometric method
GB/T 3050-2000, Inorganic chemical products for industrial use — General method for determination of chloride content — Potentiometric titration method
GB/T 6679, General rules for sampling solid chemical products
GB/T 6682-2008, Water for analytical laboratory use — Specification and test methods
GB/T 8170, Rules of rounding off for numerical values and expression and judgement of limiting values
GB 12268-2012, List of dangerous goods
GB 12463, General technical specifications for transport packages of dangerous goods
GB 15603, General rules for storage of common dangerous chemicals
HG/T 3696.1, Inorganic chemicals for industrial use — Preparations of standard and reagent solutions for chemical analysis — Part 1: Preparations of standard volumetric solutions
HG/T 3696.2, Inorganic chemicals for industrial use — Preparations of standard and reagent solutions for chemical analysis — Part 2: Preparations of impurity standard solutions
HG/T 3696.3, Inorganic chemicals for industrial use — Preparations of standard and reagent solutions for chemical analysis — Part 3: Preparations of reagent solutions and indicator solutions
UN Model Regulations, Recommendations on the Transport of Dangerous Goods
3 Terms and definitions
No terms and definitions are required to be defined in this document.
4 Molecular formula and relative molecular mass
Molecular formula: KOH
Relative molecular mass: 56.10 (based on 2022 international relative atomic masses)
5 Classification
High-quality flaky potassium hydroxide is classified into the following two types:
— Type I: 95 % specification, products with potassium hydroxide content of 95 % and above.
— Type II: 90 % specification, products with potassium hydroxide content of 90 % and above but below 95 %.
6 Requirements
6.1 Appearance: White flakes.
6.2 High-quality flaky potassium hydroxide tested in accordance with the test methods specified in this document shall comply with Table 1.
7 Test methods
7.1 General provisions
Unless otherwise specified, the reagents and water used in this document shall be of analytical grade and Grade 3 water in accordance with Table 1 of GB/T 6682-2008.
Unless otherwise specified, the standard volumetric solutions, impurity standard solutions, reagent solutions and indicator solutions used in the tests shall be prepared in accordance with HG/T 3696.1, HG/T 3696.2 and HG/T 3696.3.
7.2 Appearance inspection
Under natural light, visually inspect the appearance on a watch glass or white porcelain plate with a white background.
7.3 Determination of potassium hydroxide and potassium carbonate content
7.3.1 Principle
Barium chloride reacts with potassium carbonate in the test solution to form barium carbonate precipitate. Using phenolphthalein as indicator, the potassium hydroxide is titrated with hydrochloric acid standard volumetric solution. Then an excess of hydrochloric acid standard volumetric solution is added to react with barium carbonate, and the remaining hydrochloric acid standard volumetric solution is titrated with sodium hydroxide standard volumetric solution. The contents of potassium hydroxide and potassium carbonate are calculated.
7.3.2 Reagents or materials
7.3.2.1 Barium chloride solution: 100 g/L. Before use, add phenolphthalein indicator solution (10 g/L) and adjust to pink colour with 0.1 mol/L sodium hydroxide solution.
7.3.2.2 Hydrochloric acid standard volumetric solution I: c(HCl) ≈ 1 mol/L.
7.3.2.3 Hydrochloric acid standard volumetric solution II: c(HCl) ≈ 0.1 mol/L.
7.3.2.4 Sodium hydroxide standard volumetric solution: c(NaOH) ≈ 0.1 mol/L.
7.3.2.5 Carbon dioxide-free water.
7.3.2.6 Phenolphthalein indicator solution: 10 g/L.
7.3.3 Test procedure
7.3.3.1 Preparation of test solution A
Using a dried weighing bottle, quickly weigh approximately 40 g of the specimen (accurate to 0.01 g) and place in a 250 mL beaker. Add an appropriate amount of carbon dioxide-free water to dissolve. After cooling to room temperature, transfer completely to a 1000 mL volumetric flask, dilute to the mark with carbon dioxide-free water, and shake well. Immediately transfer to a clean, dry 1000 mL plastic bottle for storage. This solution is test solution A, used for the determination of potassium hydroxide content, potassium carbonate content, chloride content (potentiometric titration method), iron content (inductively coupled plasma optical emission spectrometry), and sodium content.
7.3.3.2 Test
Using a pipette, transfer 50 mL of test solution A into a 250 mL conical flask. Add 10 mL of barium chloride solution and shake quickly. Add 2 to 3 drops of phenolphthalein indicator solution, and immediately titrate with hydrochloric acid standard volumetric solution I until the solution becomes colourless. Record the volume of hydrochloric acid standard volumetric solution I consumed as V₁.
