SU791590A1 - Method of phosphoric acid production - Google Patents

Description

(54) METHOD FOR OBTAINING PHOSPHORIC ACID

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This invention relates to a process for the production of phosphoric acid used to obtain fertilizers.

A known method for producing phosphoric acid, which includes electrothermal processing of phosphate raw materials. The generated furnace gases containing phosphorus vapors and mineral particles are sent to electrostatic precipitators, where the latter are partially separated. Phosphorus is then separated from the furnace gases by condensation. At the same time, mineral particles are released with it. Phosphorus is precipitated and directed to incineration with hydration of the phosphoric anhydride formed and the production of phosphoric acid.

The disadvantages of this method are large, phosphorus losses and the presence of large amounts of wastewater. Thus, the mineral particles accumulated in the electrostatic precipitators are washed off with water to produce the so-called cottre milk, which must be neutralized. The loss of phosphorus in the elementary and bound form is: with cottre milk - up to 60 kg / ton of phosphorus; with phosphate sludge up to 40 kg / ton of phosphorus.

The aim of the invention is to eliminate the loss of phosphorus and reduce the amount of wastewater.

This goal is achieved by the described method of producing phosphoric acid, which includes electrothermal treatment of phosphate raw materials to produce furnace gases containing phosphorus and mineral particles, separation of the latter, condensation from phosphorus gases, its combustion and hydration of the resulting phosphoric anhydride. After electrothermal treatment, condensation

15 phosphorus from furnace gases, followed by mixing the liquid phosphorus with the mineral particles contained in it and burning it and simultaneously separating the resulting

20 melt mineral particles.

Distinctive features are the order of operations for the separation of mineral particles and phosphorus from the furnace gas and the additional mixing of phosphorus with mineral particles.

These differences prevent the loss of phosphorus and reduce the amount of wastewater by 30.

Claims (1)

Claim A method of producing phosphoric acid, which includes electrothermal processing of phosphate raw materials to produce furnace gases containing phosphorus and mineral particles, separating the latter, condensing phosphorus from gases, burning it and hydrating the resulting phosphoric anhydride, characterized in that, in order to eliminate phosphorus losses and reduce the amount wastewater, after electrothermal treatment, lead to condensation of phosphorus from furnace gases, followed by mixing of the liquid phosphorus with mineral particles contained in it, its burning and simultaneous separation of the resulting melt of mineral particles.