YS/T 575.22-2021Methods for chemical analysis of bauxite - Part 22: Determination of hydroscopic moisture - Gravimetric method (English PDF)

Foreword

This document was drafted in accordance with the provisions of GB/T 1.1-2020

"Directives for standardization - Part 1: Rules for the structure and drafting of

standardizing documents".

This document is Part 22 of YS/T 575 "Methods for chemical analysis of bauxite". YS/T

575 has published the following parts:

- Part 1: Determination of aluminium oxide content EDTA titrimetric method;

- Part 2: Determination of silicon dioxide content - Gravimetric-molybdenum blue

photometric method;

- Part 3: Determination of silicon dioxide content molybdenum blue photometric

method;

- Part 4: Determination of iron oxide content - Dichromate titrimetric method;

- Part 5: Determination of iron oxide content - Orthophenanthroline photometric

method;

- Part 6: Determination of titanium dioxide content - Diantipyrylmethane

photometric method;

- Part 7: Determination of calcium oxide content - Flame atomic absorption

spectrophotometric method;

- Part 8: Determination of magnesium oxide content - Flame atomic absorption

spectrophotometric method;

- Part 9: Determination of potassium oxide and sodium oxide content - Flame atomic

absorption spectrophotometric method;

- Part 10: Determination of manganese oxide content - Flame atomic absorption

spectrophotometric method;

- Part 11: Determination of chromium oxide content - Flame atomic absorption

spectrophotometric method;

- Part 12: Determination of vanadium pentoxide content - N-benzoy-N-

phenylhydroxylamine photometric method;

- Part 13: Determination of zinc content flame - Atomic absorption

spectrophotometric method;

- Part 14: Determination the total content of rare earth oxide - Tribromo-arsenazo

Methods for chemical analysis of bauxite - Part 22:

Determination of hydroscopic moisture - Gravimetric

method

1 Scope

This document specifies the method for determining the air-equilibrium hygroscopic

moisture content in bauxite.

This document is applicable to the determination of the hygroscopic moisture content

of air-equilibrium hygroscopic moisture in the calibration loss on ignition or sample

weighing operation of powdered bauxite ores, such as bauxite ore and concentrate,

which has a determination range of <= 5.00%.

This document is not applicable to the hygroscopic moisture trade settlement process

of powdered bauxite ores.

2 Normative references

The contents of the following documents constitute essential clauses of this document

through normative references in the text. Among them, for dated references, only the

version corresponding to the date applies to this document; for undated references, the

latest version (including all amendments) applies to this document.

GB/T 8170 Rules of rounding off for numerical values and expression and

judgement of limiting values

YS/T 575.20 Methods for chemical analysis of bauxite ores - Part 20: Preparation

of pre-dried samples

3 Terms and definitions

There are no terms and definitions that need to be defined in this document.

4 Principle

The specimen that has been left to stand in the air (so that the water content in the

specimen reaches equilibrium with the water content in the air) is placed in a 110 °C ±

5 °C oven and dried, until the mass remains constant. The mass loss before and after

drying is the air-equilibrium moisture content.

5 Instruments

6 Specimen

The sample is ground to pass through a 150 µm standard sieve.

7 Test steps

110 °C ± 5 °C for 1 h. Take it out. Cover the weighing bottle. Place it in a dryer (5.2) to

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