GB/T 18114.6-2010Chemical analysis methods of rare earth concentrates - Part 6: Determination of silicon oxide content (English PDF)

3.1

sodium hydroxide, pure class distinctions.

3.2

sodium peroxide, pure class distinctions.

3.3

anhydrous sodium carbonate, pure class distinctions.

3.4

hydrochloric acid (rho1.19g/mL), pure class distinctions.

3.5

hydrochloride (13).

3.6

Ammonia (14), pure class distinctions.

3.7

Ethanol (95%).

3.8

ammonium molybdate solution 50g/L.

3.9 oxalic acid solution of sulfuric acid mixed

under constant stirring in 965mL water was slowly added to 35mL sulfuric acid (rho1.84g/mL) and 15g

Oxalic acid (excellent pure) and mix.

3.10 ferrous ammonium sulfate solution (6%)

6g ferrous ammonium sulfate dissolved in 100mL of sulfuric acid medium (5%).

3.11 pairs nitrophenol indicator solution

1%.

Silicon 3.12 Standard stock solution. Weigh 0.1000g silica (purity > 99.9%, 120 °C drying 2H), placed in a platinum crucible, is added

5g anhydrous sodium carbonate (3.3), at 950 °C ~ 1000 °C melt to red transparent. Coolish after leaching with hot water, cooling. Moved

1000mL volumetric flask, dilute with water to volume, and mix. Immediately transferred to a polyethylene bottle preservation, this solution 1mL containing 100µg dioxide

Silicon.

3.13 Silicon standard solution

Pipette 20.00mL silicon standard stock solution (3.12) into 100mL volumetric flask, dilute to the mark with water, mix uniform. This solution 1mL containing 20µg silica, immediately transferred to a polyethylene bottle save.