Purpose:     

The coal phosphorus determination instrument (equipment) is used for measuring the phosphorus content in lignite, bituminous coal, anthracite, and coke.

Determination Method:

Follow the "GB/T 216-2003 Method for Determination of Phosphorus in Coal".

Required Reagents:

1. Hydrofluoric acid (GB/T 620): 40% (mass fraction).

2. Sulfuric acid solution: c(1/2H2SO4)=10 mol/L, measure 278 mL of concentrated sulfuric acid (GB/T 625) and slowly add it to an appropriate amount of water while stirring, then dilute with water to 1000 mL.

3. Sulfuric acid solution: c(1/2H2SO4)=7.2 mol/L, measure 200 mL of concentrated sulfuric acid, slowly add it to an appropriate amount of water while stirring, then dilute with water to 1000 mL.

4. Ammonium molybdate-sulfuric acid solution: Dissolve 17.2 g of ammonium molybdate (GB/T 657) in an appropriate amount of sulfuric acid solution (4.3), and dilute with sulfuric acid solution (4.3) to 1000 mL.

5. Ascorbic acid solution: Weigh 5 g of ascorbic acid, dissolve it in 100 mL of water, prepare fresh before use.

6. Antimony potassium tartrate solution: Weigh 0.34 g of antimony potassium tartrate, dissolve it in 250 mL of water.

7. Mixed solution: Add 10 mL of ascorbic acid solution (4.5) and 5 mL of antimony potassium tartrate solution (4.6) to 35 mL of ammonium molybdate-sulfuric acid solution (4.4), mix well, prepare before use.

8. Phosphorus standard stock solution (0.1 mg/mL): Accurately weigh 0.4392 g of potassium dihydrogen phosphate (GB/T 1274, premium grade) dried at 110°C for 1 h, dissolve in water, and dilute with water to 1000 mL.

9. Phosphorus standard working solution (0.01 mg/mL): Take 10.0 mL of phosphorus standard stock solution (4.8) and dilute with water to 100 mL, prepare before use.

Instruments and equipment required for coal phosphorus testing:

1. Analytical balance: Sensitivity 0.1 mg.

2. Muffle furnace: Equipped with temperature control device and chimney, capable of maintaining temperature at (815 ± 10)°C.

3. Spectrophotometer or photoelectric colorimeter.

4. Polytetrafluoroethylene (PTFE) crucible: Capacity 25 mL-30 mL.

5. Volumetric flasks: 50 mL, 100 mL, and 1000 mL.

6. Hot plate: Adjustable temperature.