YS/T 254.4-2011Methods for chemical analysis of beryllium concentrate and beryl. Part 4: Determination of lithium oxide contents. Flame atomic absorption spectrometry (English PDF)

Foreword

YS/T 254 "of beryllium ore, beryl chemical analysis method" is divided into seven parts.

--- Part 1. Determination of the amount of beryllium oxide phosphate gravimetric method;

--- Part 2. iron oxide contents - EDTA titration sulfosalicylic acid spectrophotometric method;

--- Part 3. Determination of phosphorus content Molybdovanadophosphoric acid spectrophotometry;

--- Part 4. Determination of the amount of lithium oxide flame atomic absorption spectrometry;

--- Part 5. Determination of the amount of fluorine ion selective electrode method;

--- Part 6. Determination of calcium oxide content by flame atomic absorption spectrometry;

--- Part 7. moisture content - Gravimetric method.

This section YS/T Part 4 254.

The partial replacement of YS/T 254.4-1994 "beryllium concentrates - beryl chemical analysis by flame atomic absorption spectrometric method for the determination of lithium oxide Amount "(formerly GB/T 5870.4-1986).

In this part, the following changes compared with the YS/T 254.4-1994.

--- Increased repeatability terms;

--- Text format has been re-edited, an increase of quality assurance and control provisions.

The non-ferrous metal part by the National Standardization Technical Committee (SAC/TC243) centralized.

This section is drafted. Xinjiang Institute of Nonferrous Metals, Xinjiang Alashankou Exit Inspection and Quarantine, Hunan Nonferrous Metals set Shuikoushan Group Limited.

1 Scope

This section YS/T 254 provisions of the beryllium ore, beryl determination of lithium oxide content.

This section applies to beryllium ore, beryl determination of lithium oxide. Determination range of 0.050% to 2.00%.

2 Method summary

Sample with ammonium fluoride, hydrofluoric acid decomposition, sulfuric smoke fluorine, after the flooding, in sulfuric acid medium, atomic absorption spectrometer wavelength 670.8nm at the air - acetylene flame measured lithium oxide.

3 Reagents

3.1 ammonium hydrogen fluoride.

3.2 Hydrofluoric acid (rho1.13g/mL).

3.3 sulfuric acid solution (11).

3.4 Standard lithium oxide stock solution. Weigh 2.4729g advance at 105 °C ~ 110 °C drying 2h and placed in the dryer to cool to room Temperature lithium carbonate [w (Li2CO3) >=99.9%], placed in 250mL beaker, add 25mL water, cover the surface of the dish, slowly dropping from cup 10mL sulfuric acid solution (3.3), and heated to completely dissolve lithium carbonate, boiling, cooled to room temperature, washed with water table dish purged, the solution is transferred 1000mL Volumetric flask, diluted with water mark and shake. 1mL of this solution is equivalent to 1000µg lithium oxide.

3.5 lithium oxide standard solution. Pipette 100.00mL lithium oxide standard stock solution (3.4), placed 1000mL volumetric flask, dilute with water Release mark and shake. 1mL of this solution is equivalent to 100µg lithium oxide.

4 Instrument

Atomic absorption spectrometer, with lithium hollow cathode lamp.

Under optimum working conditions for those who can reach the following indicators can be used.

--- Characteristic concentration. In line with the measuring solution matrix solution, characterized in lithium concentration should be less than 0.030µg/mL.

--- Precision. standard solution with the highest concentration of 10 times the absorbance measurements, the standard deviation should not exceed 1.5% of the average absorbance;

With the lowest concentration of standard solution (not "zero" concentration of the standard) measuring the absorbance of 10 times, the standard deviation should not exceed the maximum the average concentration of 0.5% absorbance.

--- Linear calibration curves. the curve is divided into five sections according to concentration, absorbance difference between the absorbance difference between the highest and the lowest segment Ratio of no greater than 0.7.

5 Sample

5.1 Beryllium concentrate, Beryl should be through the sieve of 0.074mm sieve.