SU1518297A1 - Method of producing phosphoric acid - Google Patents

Abstract

This invention relates to a process for the processing of phosphorus sludge formed during the production of phosphorus by the electrothermal method. The aim of the invention is to reduce the content of the oxidized phosphorus in the product. The method consists in heating the phosphorus sludge to 80-90 ° C, further heating before burning to 110-120 ° C, burning the sludge followed by hydration of the resulting phosphoric anhydride. 1 tab.

Description

(21) 435А68А / 23-26

(22) 04.01.88

(A6) 10/30/89. Vul. P 40

(71) Kazakh Science and Research and Design Institute with Osphoric Industry

(72) T.Z.Zhuseyev, A.M. Shirinsky, E.U.Yaumartbayev and K.L.Shimanskny (53) 661.634.2 (088.8)

(56) Thermal phosphoric acid, salts and fertilizers based on it. Ed. N.N.Mostikova. M.: XIIMHR, 1976. C.1A9-152.

(54) METHOD FOR OBTAINING PHOSPHORIC ACID

(57) The invention relates to a process for the processing of phosphorus sludge formed during the production of phosphorus by the electrothermal method. The aim of the invention is to reduce the content of the oxidized forms of phosphorus in the product. The method consists in heating the phosphorus sludge to 80-, additional heating before burning up to 110-120 s, burning PSA, followed by hydration of the formed phosphoric anhydride. 1 tab.

This invention relates to a process for the processing of phosphorus spam, which is produced in the manufacture, of a foghor by an electrothermal method.

The aim of the invention is to reduce the content of the oxidized phosphorus in the product.

Example 1. Phosphorus sludge containing 50% phosphorus, 5, OZ solids and 45% water, with temperature, n type of water in the amount of 2000 kg / h in terms of phosphorus is squeezed into the apparatus, where it is heated to 110 C, then served in nozzle cyclone chamber.

When superheated sludge is fed into the combustion chamber due to instantaneous boiling up and evaporation of water with simultaneous destruction of the sludge structure and the transfer of phosphorus to the aerosol state, complete oxidation of phosphorus to phosphoric anhydride is ensured.

On the combustion of phosphorus in the cyclone serves 10,000 air. Air excess factor, 1,}. The gaseous products of the combustion of phosphorus flow through the duct into the absorption capsule, where the hydration of phosphoric anhydride takes place and the mist of acid is trapped by circulating phosphoric acid. Fine gas purification from phosphoric acid mist is carried out in an electrostatic precipitator. By absorbing phosphoric anhydride with circulating acid and trapping the phosphoric acid mist, 5700 kg / h of phosphoric acid containing 75Z of the basic substance, 0.1% of suspended solids and 0.1% of lower phosphorus oxides are obtained.

The table shows the data on the quality of the production phosphoric acid, depending on the temperature to which the spurs are heated in front of the burner,

Reducing the temperature of overheating of the sludge to increases the content of lower forms of oxides (the phosphorus in the product is less).

(L

with:

SP

00

IND

with

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31518297

An increase in temperature is no longer feasible because, despite the low content of phosphorus oxides in the production acid, the process of supplying phosphorus-containing sludge worsens, since it boils up in the pipeline and in the injector, which leads to an increase in the hydraulic resistance of the tract and, as a result

to reduce the performance of the installation.

Claims (1)

Invention Formula A method of producing phosphoric acid, which involves melting phosphoric sludge, burning it with subsequent hydration of the resulting phosphorus andes xridus, characterized in that, in order to reduce the content of under-oxidized phosphorus in the product, before burning, the gaps are heated to 1 1T-120 sec.