GB/T 4324.16-2012Methods for chemical analysis of tungsten - Part 16: Determination of loss content on ignition - Gravimetric method (English PDF)

3.1 Sample

Weigh 2.00g sample, accurate to 0.0001g.

3.2

Determination of the number of

Independently measured twice and averaged.

3.3 Determination

3.3.1

The porcelain crucible placed 780 °C ~ 800 °C high temperature furnace burning 1h, after removing coolish cool to room temperature in desiccator, weigh. again

The porcelain crucible placed 780 °C ~ 800 °C high temperature furnace burning 0.5h, after removing coolish placed in a desiccator to cool to room temperature (cooling time should be

The previous agreement), weighing. Repeat until constant weight.

3.3.2

The sample (3.1) into constant weight porcelain crucible, placed 780 °C ~ 800 °C high temperature furnace burning 2h, after removing the cooling set

Dryer cooled to room temperature (cooling time should be consistent with an empty crucible cooling time), weighed. Then porcelain crucible at 780 °C ~ 800 °C high temperature furnace

The burning 0.5h, removed after cooling placed in a desiccator cooled to room temperature (cooling time should be consistent with an empty crucible cooling time), weighed. Repeat this

Operating until constant weight.

Calculation results of the analysis of 4

Ignition loss amount w ignition loss amount, expressed in%, according to equation (1).

w = loss on ignition m1-m2 m × 100 (1)

Where.

m --- Sample volume in units of grams (g);

m1 --- burning in front of the sample with constant weight porcelain crucible mass in grams (g);

M2 --- After burning the sample with a porcelain crucible mass in grams (g).