GB/T 20615-2026Fireworks - Determination of aluminium content in pyrotechnic composition (English PDF)

1 Scope

This document describes a method for determining the aluminum content in fireworks and firecracker gunpowder.

This document applies to the determination of aluminum content in fireworks and firecracker gunpowder.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 601 Preparation of Standard Titration Solutions for Chemical Reagents

GB/T 6682 Specifications and test methods for water used in analytical laboratories

GB/T 8170 Rules for rounding off numerical values and the representation and determination of limiting values

GB/T 41644 Test Methods for Fireworks and Firecrackers

AQ4115 Technical Specification for Preventing Static Electricity Hazards in Fireworks and Firecrackers

3 Terms and Definitions

This document does not contain any terms or definitions that need to be defined.

4 Principles

The aluminum in the sample comes from two parts. one part is aluminum powder or aluminum-magnesium alloy powder that is soluble in dilute nitric acid, and the other part is insoluble in nitric acid.

Cryolite, which is acidic but soluble in sulfuric acid, does not need to be tested for aluminum if the sample does not contain pyrotechnic powder that produces a yellow glow. The sample has undergone pre-treatment...

After treatment, the solution is dissolved in dilute nitric acid and sulfuric acid in sequence, then filtered, the pH of the solution is adjusted, and a precipitant is added to separate the aluminum ions from the solution.

Disodium ethylenediaminetetraacetate (EDTA) complexometric titration at pH 10.0 using 1-(2-pyridiniazo)-2-naphthol (PAN) as an indicator

One portion of the test solution was prepared by adding an appropriate amount of ammonium fluoride to mask aluminum ions, while the other portion was prepared by adding EDTA directly without ammonium fluoride, and then using sulfuric acid.

The endpoint is reached when the copper standard titrant changes from yellow to blue. The titration is determined by the volume of copper sulfate standard titrant consumed in both titrations.

The aluminum content in the sample was calculated by difference.

5 Reaction Formula

The reaction formula is as follows.

Al3H2Y2-=AlY-2H

Al3 6F-=(AlF6)3-

2Na3AlF6 6H2SO4=3Na2SO4 Al2(SO4)3 12HF-> […]