Лаборатория иши №5

S = (a • 98 • 100) / (56 • 75 • r)
Here:
the amount of SaO in α-phosphate;
r- Density of sulfuric acid.
The amount of dilute solution100 gramsfor phosphate is determined by the following formula:
W = F- (100 + SG)
Here:
The amount of G-gas losses;
F-pulpani weight.

The weight of the pulp is found as follows:

F = 100 ∙ G (n + 1)
Here:
G-gypsum number, (G = 1.6 for apatites, G = 1.3 for phospharite;
n-the ratio of liquid to solid in the pulp is n = (2: 1-4: 1).
We measure the required amount of dilute solution using a measuring cylinder and pour into a mixing beaker. It is lowered into the mixer and the tile is lit. We put a thermometer in the glass to control the temperature. When the temperature reaches 50 ° C, the measured phosphate is added. Then slowly H2SO4solution is poured. We continue to mix the resulting pulp at 75-80 ° C. The process of phosphate decomposition is carried out for 2-4 hours. When the process is complete, the pulp is filtered. The sediment is washed with water. And added to the filtrate and poured into a measuring tube. In a volumetric flask, bring the solution to 250 ml, measure 25 ml of the solution and titrate using a 0.1 N NaOH solution.





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Figure.4.1. Extraction phosphoric acid extraction device
1 - main reactor; 2 - thermometer; 3 - electric motor; 4 - glass mixer;
5 - electric hob.

Phosphate decomposition coefficient Kparch is found from the following formula:

Kparch = 0.7 · 100 / (SaO / SO3)

Here, 0.7 is the theoretical weight ratio of SaO and SO3 in gypsum.

The solubility coefficient of R2O5 is found from the following formula:

Kot = 100- {([R2O5umum] - [R2O5vodor]) Gg · 100} / [R2O5fosf]

Here, [R2O5umum], [R2O5vodor], [R2O5phosph] are the amounts and weights of total and water-soluble R2O5 in wet or dry phosphogypsum and R2O5 in phosphate;

Gg is the amount of precipitate obtained in relation to phosphate; g.