SU891592A1 - Method of producing superphosphate - Google Patents

Description

(FOR) METHOD OF OBTAINING SUPERPHOSPHATE

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The invention relates to the production of mineral fertilizers and can be used to obtain a defluorinated superphosphate.

A known method for producing superphosphate is by decomposing a phosphate raw material with sulfuric acid in the presence of an addition of sodium sulfate.

The disadvantage of this method is the high fluorine content in the product (55-60% of its content in the feedstock.

There is also known a method for producing superphosphate by decomposing a phosphate raw material with sulfuric acid with the addition of silica 2.

However, the chamber superphosphate obtained in this way contains a large amount of fluorine (1.3-1.6%), which decreases slightly when the product is aged (to 0.85-1.1%).

The purpose of the invention is to reduce the fluorine content in the product.

This goal is achieved. According to the method for producing superphosphate, which includes the decomposition of phosphate raw materials with sulfuric acid in the presence of a silicon-containing additive, liquid glass is used as the silicon-containing additive.

At the same time, liquid glass is introduced in the amount of 2-6% by weight of the phosphate raw material.

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Liquid glass has the following chemical composition, wt.%: 510276; A1203.5; MqO 1.5; 17.8; CaO 3.2.

As a result of the implementation of the proposed method, the fluorine content in the resulting chamber superphosphate is reduced to 0.57–0.81%, and after its maturation to 0.22–0.51%.

Example 1. 60 ml of 68% spent sulfuric acid (at a rate of 70 parts by weight per 100 parts by weight of apatite concentrate) are placed in a porcelain stan20 with a capacity of 0.5 l and heated

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Before and gradually pour 100 g of apatite concentrate. After a brief and thorough mixing, liquid glass is introduced in an amount of 2.07, by weight of apatite. The glass is placed in a thermostat at about 3 hours. The product is then removed from the beaker, cooled, and analyzed for all types. and the fluorine content in the chamber and finished mature product.

Fluorine content in fresh chamber superphosphate 0.81%, 5%;

2 6-vcB.i %% voAor1 "° doping of fluorine in the mature ready-made superphosphate 0.51%.

, PRI mme R 2. Similar to example 1, the amount of liquid glass 4%.

The fluorine content in fresh chamber superphosphate is 0.65%. ..5.3%; PjOgycB. 20.1%; RDS dar. 19.4%, the fluorine content in the finished mature product is 0.25%,

Example 3. Similar to example 1, the amount of liquid glass 6%.

Fluorine content in fresh chamber superphosphate 0.57%; EjCL.cBo6 .. 5.3%; . 20.4%; P With water. 19, .6%, the fluorine content in the mature finished superphosphate 0.22% ..

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The proposed method makes it possible to accelerate the release of fluoride compounds in the mixing zone of phosphate raw material with sulfuric acid, increase the number of sources of deficient fluorine and reduce the release of fluoride soybean into the environment.

Claims (2)

1. A method of producing superphosphate by decomposing a phosphate raw material with sulfuric acid in the presence of a silicon-containing additive, soaking, so that, in order to reduce the fluorine content in the product, liquid glass is used as the silicon-containing additive. 2. The method according to Claim I., of that, and with the fact that liquid glass is introduced in an amount of 2-6% by weight of the phosphate raw material. Sources of information taken into account in the examination 1. Sokolovsky A-.A. and Unan nts G.P. A brief guide to mineral fertilizers M. M., Himi, 1977, p.140. 2. Pozin M.E. Mineral salt technology. L., 7mm, 1970, p.859 (prototype).