SU1373686A1 - Method of producing barium carbonate - Google Patents

Abstract

The invention relates to methods for producing barium carbonate and can be used in chemical applications. The invention makes it possible to obtain barium carbonate with a reduced content of strontium impurities in the target product by evaporation of the barium chloride solution to its concentration in the mother liquor, equal to 210-300 g / dm, before treatment with sodium carbonate.

Description

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This invention relates to methods for producing barium carbonate and may be used in the chemical industry.

One of the consumers of barium carbonate is the production of radio fermics, in particular capacitors, in the technology of which barium carbonate is used to produce barium titanate. In this case, barium carbonate is subject to qualitative composition, in particular, the content of strontium impurity in it (mass dgp strontium in barium carbonate supplied for the needs of radioceramics should not exceed 0.4%)

The aim of the invention is to reduce the content of strontium in the target product.

Example 1 1110 kg of barite concentrate with a 92% BaSO mass fraction mixed with coke is reduced in a rotary drum furnace. The resulting 903.5 kg of barium sulphide alloy with a mass fraction of the sum of water and acid-soluble barium sulfide (82%) is expelled with water, followed by treatment of the resulting suspension with hydrochloric acid to pH 2-2.5 and sodium hydroxide to pH 7-8.5. barium chloride is separated from the insoluble residue, and the resulting 5472 kg of a clarified solution with a content of 200 g / dm of chloride are digested for evaporation until a suspension of barium crystals is formed. To achieve a barium chloride concentration in the magnetized slurry solution of 210 g / dm, the slurry is separated to obtain 780 kg of barium chloride crystals and 1525 kg of mother liquor. The separated barium chloride crystals are dissolved in water. The resulting 3332 kg of barium chloride solution with a concentration of 240 g / dm is mixed with 1855 Kf of sodium carbonate solution with a concentration of 220 g / dm. The barium carbonate suspension formed is dried and separated on a vacuum filter. 872.8 kg of barium carbonate paste with a moisture content of 30% is washed, dried, and then 610 kg of sodium carbonate are obtained with a mass fraction of strontium equal to 0.25%,

Example 2, 5472 kg of a clarified solution containing 200 g / dm of barium chloride, also obtained.

as in Example 1, evaporation is carried out to form barium chloride crystals. When the barium chloride concentration in the mother liquor of the suspension is equal to 260 g / dm, the suspension is separated to obtain 730 kg of barium chloride crystals and 1497 kg of the mother liquor. The separated barium chloride crystals are dissolved in water. The obtained 3115 kg of barium chloride with a concentration of 240 g / dm is mixed with 1738 kg of a solution of carbonate of sodium at a concentration of 220 g / dm - 815.8 kg of barium carbonate paste with a moisture content of 30% is separated from the resulting barium carbonate suspension, washed, dried, and 570 are obtained , 5 kg of barium carbonate with a mass fraction of strontium equal to 0.18%.

Example 3 5472 kg of a clarified solution with a content of 200 g / dm of barium chloride, obtained in the same way as in example 1, are sent for evaporation to form chlorine and barium crystals. Upon reaching a barium chloride concentration in the mother liquor of 300 g / dm, the suspension is separated to obtain 690 kg of barium chloride crystals and 1480 kg of the mother liquor. The separated barium chloride crystals are dissolved in water. The resulting 2947 kg of barium chloride solution with a concentration of 240 g / dm is mixed with 1645 kg of a solution of sodium carbonate with a concentration of 220 g / dm. Barium carbonate suspensions are separated into 772 kg of barium carbonate paste with a moisture content of 30%, washed and dried, after which 540 kg of barium carbonate with a strontium mass fraction of 0.08% is obtained.

Data on the content of impurities of strontium in the target product are given in the table.

As can be seen from the data in the table, the technical and economic advantages of the proposed method as compared to the known one consist in reducing the content of strontium impurities in the target product from 1.56 to 0.08-0.25%, which makes the product meet the requirements of radioceramic production. .

It was established experimentally that evaporation of a barium chloride solution to a barium chloride concentration in it less than 210 g / dm causes the simultaneous

but with barium chloride, strontium chloride, which is present in the mother liquor, begins to fall out, which then goes into the final product.

When going beyond the upper concentration limit (300 g / dm), there is no any noticeable further decrease in the mass fraction of strontium in barium chloride, but at the same time the yield of crystalline barium chloride decreases in the process of obtaining barium carbonate, and accordingly, in stages “Of the target product with .unm of strontium,

Claims (1)

Invention Formula The method of producing barium carbonate by reducing the barite concentrate, the aqueous solution of melting barium sulphide, followed by treatment of the resulting suspension with hydrochloric acid, alkalizing the suspension, separating the insoluble residue from the barium chloride solution, treating the latter with sodium carbonate, separating the precipitate of barium carbonate and drying it, so as to reduce strontium content in the target product Before the treatment with sodium carbonate, the barium chloride solution is evaporated to form a suspension of crystals: barium loride with a concentration of pulp in the mother solution equal to 210–300 g / dm, barium chloride crystals from the mother liquor, they are dissolved in water and the resulting solution was treated with sodium carbonate. 1 2 3 four Famous Output reduction to 60Z 1.56