YS/T 254.1-2011Methods for chemical analysis of beryllium concentrate and beryl. Part 1: Determination of beryllium oxide content. Phosphate gravimetry (English PDF)

3.8 Diammonium hydrogen phosphate solution (132.5 g/L): Weigh 132.5 g of

diammonium hydrogen phosphate. Dissolve in 500 mL of water. Filter. Transfer to a

5.3.3 Move the platinum dish into a 700°C high temperature furnace. Melt it until it becomes transparent. Take out. Cool down.

5.3.4 Wipe the outer wall of the platinum dish. Dip the melt into a 400 mL beaker with hot water. Add 5 mL of hydrochloric acid (3.3). Heat and boil to make the solution clear.

5.3.5 Add 3 mL of hydrogen peroxide (3.4), 10 mL of disodium

ethylenediaminetetraacetate solution (3.9), and 8 mL of diammonium hydrogen phosphate solution (3.8) into the beaker. Neutralize with ammonia water (3.5) until obvious precipitation appears. Slowly add 20 mL of ammonium acetate solution (3.10) while stirring. Heat and boil for 2 min ~ 3 min.

5.3.6 Place the beaker in a boiling water bath to keep it warm. Convert the precipitate into crystalline precipitate. Cool down. Leave for more than 4 h.

5.3.7 Filter with slow quantitative filter paper. Wash the beaker and sediment 4~5 times with hot ammonium nitrate solution (3.11).

5.3.8 Use 20 mL of hot hydrochloric acid solution (3.6) to dissolve the precipitate from the funnel into the original beaker. Wash the filter paper several times with hot water.

Dilute the solution with water to a volume of approximately 100 mL.

5.3.9 Add 1 mL of hydrogen peroxide (3.4), 5 mL of disodium

ethylenediaminetetraacetate solution (3.9), and 4 mL of diammonium hydrogen phosphate solution (3.8) into the beaker. Neutralize with ammonia water (3.5) until obvious precipitation appears. Slowly add 20 mL of ammonium acetate solution (3.10) while stirring. Heat and boil for 2 min ~ 3 min.

5.3.10 Place the beaker in a boiling water bath to keep it warm. Convert the precipitate into crystalline precipitate. Cool down. Leave for more than 4 h.

5.3.11 Filter with slow quantitative filter paper. Wipe the beaker clean with half a piece of filter paper. Wash with hot ammonium nitrate solution (3.11) until there is no chloride ion [check with silver nitrate (3.12)].

5.3.12 Place the precipitate together with the filter paper in a constant weight crucible (porcelain or corundum). Carefully dry and ashes. Place it in a high temperature furnace of 1000°C and burn it for 2 h. Take out. Cool slightly. Place in a desiccator to cool to room temperature. Weigh. Then put the crucible into a high temperature furnace of

1000°C. Burn it for 1 h. take out. Cool slightly and then place in a desiccator to cool to room temperature. Weigh to constant.