Standard No.:	GB/T 15057.8-1994
Chinese Name:	化工用石灰石中硫含量的测定 硫酸钡重量法和燃烧--碘酸钾滴定法
English Name:	Limestone for chemical industry- Determination of sulfur content- Gravimetric and combustion-iodate titrimetric methods
Professional Classification:	D53 Building material raw material ore
Professional Classification:	GB National Standard
ICS Classification:	73.080
Issued by:
Issued on:	1994-05-05
Implemented on:	1995-02-01
Status:	VALID
Language:	English
File Format:	PDF
Word Count:	3000 words
Price(USD):	90 (USD)
Delivery:	via email in 1-3 business day

Section I Gravimetric Method

1 Subject Content and Application Scope

This standard specifies the determination of sulfur content by barium sulfate gravimetric method.

This standard is applicable to the determination of sulfur content in limestone products for chemical industry and the determination range is greater than 0.05%.

2 Normative Reference

GB 6682 Water for Analytical Laboratory Use - Specification and Test Methods

3 Method Summary

Decompose the specimen with nitric acid and potassium chlorate, oxidize sulfur to sulfate, add hydrochloric acid and evaporate to dryness, so as to remove the nitric acid. Filter the solution to remove insoluble substances like silicon; in hydrochloric acid medium with pH value of about 1, add barium chloride to generate barium sulfate precipitate. Then, filter out the barium sulfate, precipitate, ignite and weigh it, and then calculate the sulfur content by the mass of barium sulfate. ?

4 Reagents and Solutions

Water used in this standard shall conform to the specification of Grade 3 water specified in GB 6682; unless otherwise specified, the adopted reagents refer to analytical reagents.

4.1 Potassium chlorate (GB 645).

4.2 Nitric acid (GB 626) solution: 1+1.

4.3 Hydrochloric acid (GB 622).

4.4 Hydrochloric acid solution: 1+1.

4.5 Hydrochloric acid solution: 1+100.

4.6 Hydroxylamine hydrochloride (GB 6685) solution: 50g/L.