SU833490A1 - Method of phosphoric acid production - Google Patents

Description

(54) (METHOD FOR OBTAINING PHOSPHORIC ACID

one

The invention relates to methods for the preparation of phosphoric acid cleaned solutions and can be used for the production of technical, feed and food salts.

A known method of producing forsporic acid involves the decomposition of phosphate raw materials into recycled phosphoric and sulfuric acids with simultaneous grinding to a grinding fineness of 0.2–5 µm and at 25–60 ° C, followed by crystallization and separation of calcium sulfate. Phosphoric acid is obtained, -containing iron, aluminum, fluorine, sulfate ion 1 as impurities.

The disadvantages of this method are the high content of impurities, the irreversible consumption of reagent - (sulfuric acid) and the complexity of the process.

There is also known a method of producing phosphoric acid, including the decomposition of phosphate raw materials with sulfuric acid in a mixture with aliphatic alcohol (butyl, amyl) with a solid-liquid ratio of 1: 2.5-4.5 with low displacement followed by separation of the alcohol phase from the solid residue, treating it with water, liberating phosphoric acid, distilling the alcohol from the aqueous solution by distillation, and returning the alcohol to the process. A 73% phosphoric acid is obtained, from which impurities are removed at 81 - 860/0 2.

The disadvantages of this method are the complexity of the process, the irreversible consumption of the reagent - sulfuric acid, the high content of impurities,%: R, O - 0.22, F - I.

The purpose of the invention is to simplify the process by reducing the number of stages, as well as eliminating the consumption of sulfuric acid and reducing the content of impurities in the product.

This goal is achieved by the method of obtaining phosphoric acid, which consists in treating the phosphate raw material with aliphatic alcohol at a solid-to-organic ratio of 1: (1-2) at a stirring rate. 20-100 m / s with grinding media with a weight ratio of filling of the raw material to grinding bodies equal to 2-10 ° / o, separation of the acid-organic mixture from the solid residue.

separation of phosphoric acid from the organic phase and its subsequent return to the process.

Under these conditions, a mechanical activation occurs, due to which the bonds are broken and the ions are released from the crystal lattice. The magnitude of the stirring speed of less than 20 m / s is insufficient for breaking the bonds, which ultimately results in a reduced concentration of phosphoric acid, and an increase in the mixing speed of more than 100 m / s is not economically feasible. The ratio of filling the raw material to the grinding bodies of less than 2% significantly reduces the productivity of the equipment, and an increase in the ratio of more than 10% does not allow to achieve the degree of extraction of phosphate raw materials more. With a solid-to-organic ratio of less than 1, the degree of extraction from the raw material is insufficient, and with a ratio of more than 2 it increases with the content of impurities in phosphoric acid.

Example 1. 300 g of Khibiny apatite concentrate containing 39.2% are mixed with 300 g of isopropyl alcohol containing 20% water. The resulting mixture is subjected to mechanical activation in a planetary-type apparatus at 20 ° C and a stirring speed of 100 m / s for 30 minutes. The ratio of filling of raw materials to GRADUATING bodies is 2%. The solid phase is then separated from the mixture of phosphoric acid and alcohol. The mixture is distilled to obtain phosphoric acid containing 42.9% of Pa.Oy and traces of fluorine. The degree of extraction from chapatite is 96%. The impurity content of 0.17%,

Example 2. 300 g of Karatau phosphate concentrate containing 28.5% is shifted from 450 g of propionic alcohol containing 30% water. The mixture obtained is activated in a vibratory grinder at 15 ° C and a stirring speed of 50 m / s for 1 hour. The ratio of filling of the raw material to the grinding bodies is 10%. The solid phase is then separated from the mixture of phosphoric acid and alcohol. The mixture is distilled, resulting in phosphoric acid containing 39.2% and traces of fluorine. The degree of extraction of phosphate 93.5%. The impurity content is 0.227. Example 3. 300 kg of a concentrate of Eno-Kovdorsky appatite containing 33.3% 1a are mixed with 600 g of ethyl alcohol containing 15% of water. The resulting mixture is subjected to mechanical activation in a planetary mill at 17 ° C and a stirring speed of 20 m / s for 45 minutes. The ratio of filling of raw materials to grinding bodies is 5%. The solid phase is then separated from the mixture of phosphoric acid and alcohol. The mixture is distilled to obtain phosphoric acid containing 51.1%. The degree of recovery of PiOff is 96%. The impurity content of 0.26%. Using the proposed method will simplify the process by conducting it in the rd stage for 30–60 minutes at 15–20 ° C, reducing the content of impurities in the acid to 0.17–0.26 and eliminating the use of sulfuric acid.

 formula of invention

A method of producing phosphoric acid, which involves treating the phosphate raw material with aliphatic alcohol with stirring, separating the organic phase from the solid residue and phosphoric acid from the organic phase, and then returning it to a process that is characterized in that, in order to simplify the process by reducing the number of stages, eliminating consumption sulfuric acid and reducing the content of impurities in the product, the treatment is carried out at a solid: organic ratio of 1: (1-2), and mixing is carried out at a speed of 20-100 m / s using grinding filling bodies with respect to the feed grinding bodies 2-10 wt. %

Sources of information taken into account in the examination

1. USSR Author's Certificate No. 611881, cl. From 01 to 25/22, 25.06.78.

2. The UK patent number 1144806, cl. C 1 A, 12.03.69.

Claims (2)

Claim A method of producing phosphoric acid, including treating the phosphate feed with aliphatic alcohol with stirring, separating the organic phase from the solid residue and phosphoric acid from the organic phase, followed by returning it to the process, characterized in that, in order to simplify the process by reducing the number of stages, eliminating flow of sulfuric acid and ₃₅ reduce the content of impurities in the product, the treatment is carried with a ratio of the solid and the organic phase being 1: (1-2) and stirring is continued at a speed of 20-100 m / sec through melyu their filling bodies with respect to raw grinding bodies 2-10 wt.%. 40 Sources of information taken into account in the examination 1. USSR author's certificate No. 611881, cl. C 01 B 25/22, 06/25/78. 2. UK patent No. 1144806, CL C 1 A, 3/12/69.