YS/T 575.3-2007Methods for chemical analysis of bauxite. Part 3: Determination of silicon dioxide content. Molybdenum blue photometric method (English PDF)

Foreword

YS/T 575-2007 Methods for Chemical Analysis of Bauxite is a modification to YS/T

575-2006 (formerly GB/T 3257-1999). It has 24 parts in total.

--- Part 1.Determination of aluminum 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 - Potassium 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, 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-benzoyl-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

photometric method;

--- Part 15.Determination of gallium oxide content - Rhodamine B-extraction

photometric method;

--- Part 16.Determination of phosphorus pentoxide content - Molybdenum blue

spectrophotometric method;

--- Part 17.Determination of sulfur content - Direct combustion-iodometric method;

--- Part 18.Determination of total carbon content - Non-aqueous titrimetric method

after combustion;

--- Part 19.Determination of the loss on ignition - Gravimetric method;

--- Part 20.Preparation of pre-dried sample;

--- Part 21.Determination of organic carbon content titrimetric method;

--- Part 22.Determination of hydroscopic moisture in analytical samples -

Gravimetric method;

--- Part 23.Determination of element contents X-ray fluorescence spectrometric

method;

--- Part 24.Determination of carbon content and sulfur content - Infrared absorption

method.

This Part is Part 3.

This Part replaces YS/T 575.3-2006 (formerly GB/T 3257.3-1999).

This Part revises YS/T 575.3-2006.Compared with YS/T 575.3-2006, this Part has the

major changes as follows.

--- Adjust the concentrations of ammonium molybdate solution and sulfuric acid-

oxalic acid-ferrous ammonium sulfate solution;

--- Improve the melting method of silicon dioxide standard solution;

--- Specify the storage time of the sulfuric acid-oxalic acid-ferrous ammonium

sulfate mixed solution;

--- Specify the storage time after adding acid-oxalic acid-ferrous ammonium sulfate

mixed solution;

--- Changed the concentration and amount of added hydrochloric acid when

drawing the working curve;

--- Modify the wavelength of the silicon dioxide;

--- Unify the drying temperature of the sample to 110°C±5°C;

--- Add the precision.

This Part was proposed by and under the jurisdiction of National Technical Committee

on Non-ferrous Metals of Standardization Administration of China.

Chief drafting organization of this Part. China Aluminum Corporation Zhengzhou

Research Institute.

Drafting organization of this Part. China Aluminum Corporation Guizhou Branch.

Chief drafting staffs of this Part. Wang Baosheng, Lin Xingming, and Li Yunliang.

This Part shall be interpreted by National Technical Committee on Non-ferrous Metals

of Standardization Administration of China.

The historical edition replaced by this Standard is as follows.

--- YS/T 575.3-2006 (formerly GB/T 3257.3-1999).

Methods for Chemical Analysis of Bauxite -

Part 3.Determination of Silicon Dioxide Content -

Molybdenum Blue Photometric Method

1 Scope

This Part specifies the determination of silicon dioxide content in bauxite.

This Part is applicable to the determination of silicon dioxide content in bauxite; the

measurement range. <=15.00%.

2 Method Principle

The specimen was melted with alkali, leached with hydrochloric acid; add ammonium

molybdate to form silicon molybdenum heteropoly acid; and then reduced to

molybdenum blue by ferrous iron. Use a spectrophotometer to measure the

absorbance at a wavelength of 700 nm.

3 Reagents

4 Apparatus

Spectrophotometer.

5 Specimen

Grind the specimen by a mortar and pass through a 74µm sieve; dry the ground

specimen at 110°C±5°C for 2h; place it into a desiccator; cool off to the room

temperature for later-use.

6 Analysis Procedures

7 Calculation of Analysis Results

Calculate the mass fraction (%) of silicon dioxide as per the following Formula.

8 Precision

9 Quality Assurance and Control

In analysis, use standard sample or control sample to verify. Or, use standard sample

or control sample to verify the analysis method at least once a year.

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