GB/T 8151.4-2012Methods for chemical analysis of zinc concentrates - Part 4: Determination of silicon dioxide content - Molybdenum blue spectrophotometry (English PDF)

3.1

sodium hydroxide, pure class distinctions.

3.2

sulfate (11).

3.3

sulfate (19).

3.4

Aqueous ammonia (11).

3.5

ammonium molybdate solution (80g/L), filtered to use.

3.6

ascorbic acid solution (20g/L), the day of preparation.

3.7

pairs nitrophenol solution (1g/L).

3.8 dope also

ascorbic acid (3.6) and sulfuric acid (3.2) by mixing ratio 1.2, the time is now equipped with.

3.9 silica standard stock solution

Weigh 0.5000g superior grade pure silica (previously calcined at 950 °C 30min, placed in the dryer

Cooled to room temperature) in the mixed flux containing 5g (duplicate copy of anhydrous sodium carbonate and potassium carbonate mix) platinum crucible, mix, then cover 2g

Mixed flux and placed 900 °C ~ 950 °C high temperature furnace melting 1h, coolish, the crucible external water purged after a clean place 300mL polytetrafluoroethylene

Fluoride beaker, add 150mL of hot water extraction, wash the crucible, cooled, diluted with water to a 500 mL, the solution containing 1mg 1ml dioxide silicon. Store in plastic bottle.

3.10 Silica Standard Solution

Pipette silica 50.00mL standard stock solution (3.9) in 500mL volumetric flask, diluted with water

To the mark, and mix. This solution 1mL containing 100µg silica. Store in plastic bottle.

5.1

Samples should sift through the 0.100mm hole.