GB/T 23513.1-2009Chemical analysis methods for germanium concentrate - Part 1: Determination of germanium content - Potassium iodate titration (English PDF)

3.9 Sulfate (rho 1.83 g/mL)

Weigh samples (4.1) according to Table 1. Place into a 300 mL conical flask. Add 10 ml of water and shake it well. Add 10 ml of phosphoric acid (3.8), 2 g of potassium permanganate (3.5), and 0.2 g of ammonium fluoride (3.6). Heat it at low temperature to decompose. Maintain at purple color. If the purple fades away, supplement it with a little of potassium permanganate (3.5) until it is completely decomposed; and until the white smoke decomposed by fine phosphoric acid occurs. Take down and cool it. Add 120 ml of hydrochloric acid (3.10) in a conical flask. The following operation is the same as 5.1.1.4~5.1.1.6.

5.1.3 Method III

It applies to determine germanium in samples such as crude germanium dioxide with lower-impurity.

Weigh sample (4.1) according to Table 1. Place into a 300 mL conical flask. Add 10 ml of water and shake it well. Add 1 g of sodium hydroxide (3.3) to heat to completely dissolve.

Take down. Add 80 ml of water, 35 mL of phosphoric acid (3.8), and 7 g of hypophosphite (3.4). Shake to dissolve. Then cover the Geiger funnel. The following operation is the same as 5.1.1.6.

5.2 The determination of hydrochloric acid soluble germanium

Weigh samples (4.1) according to Table 1. Place into a 300 mL conical flask. Add 0.1 g of potassium permanganate (3.5) and 80 ml of hydrochloric acid (1+1). The following operation is the same as 5.1.1.5 ~ 5.1.1.6.

6.1 Mass fraction of germanium

Calculate the mass fraction of germanium according to Formula (1).

Where w (Ge) - The mass fraction of germanium, %; c - The concentration of standard solution (1/6KIO3), the unit is moles per liter (mol/L);

V - The amount of standard potassium iodate solution, the unit is milliliters (mL);

V0 - The amount of standard potassium iodate solution in blank test, the unit is milliliters (mL); m - Mass analysis sample, the unit is gram (g). control, the root cause reason shall be found out; and re-verify it after correcting the error. […]