T/GZNFS 001.5-2019 Active Group standards

T/GZNFS 001.5-2019 Chemical Analysis Methods for Tungsten Slag - Part 5: Determination of Calcium Content

T/GZNFS 001.5-2019

Publish Date: 2019-12-02 Implement Date: 2019-12-02 For services related to genuine standard inquiry, procurement, translation, and other related services in China, please Contact Us

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Basic Information

Standard Code: T/GZNFS 001.5-2019

Standard Type: Group standards

Standard Status: Active

is_force_gb: no

CCS Name: Metal chemical analysis methods

ICS Name: Other non-ferrous metals and their alloys

Publish Date: 2019-12-02

Implement Date: 2019-12-02

Scope

Scope: This section specifies the method for determining the calcium content in the alkali leach slag produced during the production of ammonium paratungstate. This section is applicable to the determination of calcium content in the alkali leach slag produced during the production of ammonium paratungstate. The determination range (mass fraction): 10.00% to 30.00%; Main technical content: The sample is dissolved with hydrofluoric acid and sulfuric acid, and then extracted with saturated ammonium oxalate, so that calcium precipitates as calcium oxalate and is separated from tungsten, iron, and manganese. After filtration, the precipitate is dissolved with nitric acid and perchloric acid and the filter paper is destroyed. In a dilute hydrochloric acid solution, the residual iron and manganese are masked with triethanolamine. With chrysoidine-phenolphthalein as an indicator, the titration is performed with EDTA standard solution when the pH value is greater than 12.