RU1838234C - Method for producing thermal phosphoric acid - Google Patents

Abstract

The method of producing thermal phosphoric acid consists in burning phosphorus, followed by cooling the gases formed and hydrating phosphoric anhydride at an excess pressure of 1000-3000 Pa. The yield of product is 98.2%. 1 tab.

Description

The invention relates to a process for the production of thermal phosphoric acid used for the production of fertilizers, feed phosphates and industrial salts.

The purpose of the invention is to increase productivity and yield.

An increase in pressure in the gas phase increases the rate and degree of oxidation of phosphorus to phosphoric anhydride, as well as the degree of hydration of phosphoric anhydride with the liquid phase in the atomized state, which provides an increase in the yield of the finished product and the productivity of the process line.

It has been experimentally established that in systems for the combustion of phosphorus and hydration of phosphoric anhydride at an excess pressure of 1000 Pa, the rate and degree of oxidation of phosphorus to phosphoric anhydride and the degree of hydration are reduced

phosphoric anhydride, which reduces the yield of the finished product and the productivity of the technological thread.

At an overpressure of more than 3000 Pa, the equipment is sealed, which leads to the loss of phosphoric anhydride and, accordingly, to a decrease in the yield of the finished product and the productivity of the process thread.

Example. 2.5t / h of molten phosphorus is fed to the nozzle of the combustion tower. Phosphorus is burned at an excess air ratio of a. 1,5. The resulting gas containing phosphoric anhydride is cooled and hydrated in a hydration tower.

The combustion and hydration systems operate at an overpressure of 2000 Pa. Unabsorbed gas and a phosphoric acid mist are fed to a venturi scrubber where diluted phosphoric is injected

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an acid having a density of 1.3 t / m, which is controlled by the flow of water to the venturi. The irrigation density in the Venturi scrubber is 400 m / m2 h. The yield of 100% phosphoric acid is 98.2%, the productivity of the production line is 8085 kg / h.

Phosphoric acid is similarly produced by changing the overpressure in the combustion and hydration system,

The dependence of product yield and production line productivity on pressure in the combustion and hydration system is presented in the table.

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Claims (1)

The use of this technical solution makes it possible to increase the yield of 100% phosphoric acid to 98.2%. and the productivity of the production line is up to 8085 kg / h. SUMMARY OF THE INVENTION A method for producing thermal phosphoric acid, comprising burning phosphorus, followed by cooling the gases formed and hydrating phosphoric anhydride, characterized in that, in order to increase the productivity and yield of the finished product, the combustion and hydration of phosphoric anhydride is carried out at an overpressure of 1000-3000 Pa.