SU796237A1 - Method of producing feed calcium phosphate - Google Patents

Description

The goal is achieved by treating an ammoniated solution obtained by decomposing natural phosphates with nitric acid, cooling the nitric acid extract and separating calcium nitrate from the mother liquor, further processing it with sodium salts and neutralizing the nitrogen phosphate solution with ammonium with intermediate separation of impurities. ammonia to a pH of 3.5-5.0 is carried out in the presence of a circulating solution in an amount of 15-100% by weight of the ammoniated solution, followed by feeding of calcium nitrate qi in an amount that provides the ratio of CaO: in the pulp of 0.75-0.55: 1. The treatment with ammonia is carried out for 20-40 minutes.

Example 1. As the raw material used apatite concentrate containing 39.4 wt.% And 51.6 wt.% CaO.

109 kg of apatite concentrate decompose 270 kg of 54% nitric acid. 370 kg of nitric acid extract is cooled to -15 ° C and a section of 195 kg of calcium nitrate. 175 kg of filtrate (20.8% PdOd; 2.84% CaO and 0.78% F) are treated with 2.3 kg of soda ash and 1.8 kg are separated. To 175 kg of the obtained nitrogen-phosphate solution, 26.3 kg of a working solution (15% by weight of the ammoniated solution) obtained after separation of the finished product are added and 38 kg of ammonia are neutralized to a pH of 1.9 and 5.2 kg of impurities are separated. 234.6 kg of solution (10.2%; 1.56% CaO and 0.007% F) mixing for 20 minutes from 42.5 kg of four-input calcium nitrate to maintain the ratio CaDtP-j Og at the stage of 0.55: 1 and 20 kg of ammonia are ammoniated to a pH of 3.5, followed by supplying 25.4 kg of calcium nitrate (up to a stoichiometric amount for CaHPO formation) i, and 10 kg of ammonia to a pH of 5.01 Pulp in the filter; 332.5 kg is filtered with release of 40 kg of Jp and calcium deposits. The filtrate is divided into two streams: 26.3 kg is circulated to the stage of precipitation of dicalcium phosphate (working solution and 266f2 kg is processed to ammonium nitrate.

The dry washed sediment in the amount of 29.4 kg has the following composition: 4c, 6% 0.5% CaO and 0.14% F. The removal of the wet, unwashed sediment is 2.5 tons from 1 m of filter per hour instead of 1.5 tons by a known method. The RO yield to the final product is 55% versus 40% by the known method.

Example 2. K175.5 kg of the nitrogen-phosphate solution obtained in Example 1 was added 70.2 kg of the working solution (40% by weight of the ammoniated solution) obtained after separating the finished product, neutralized with 38 kg of ammonia to a pH of 1.9 and separated 5.2 kg of impurities. 278.5 kg e of the solution is mixed for 30 minutes with 56.7 kg of four-input calcium nitrate to maintain the CaO: Ps O5 ratio at this stage of 0.66: 1 and 20 kg of ammonia are ammoniated to a pH of 3.5

- with the subsequent submission of 14.2 kg of calcium nitrate and 10 kg of ammonia to a pH of 5.0. Pulp in the amount of 379.4 kg is filtered with the release of 42 kg of dicalcium phosphate. The filtrate is divided into two streams: 70.2 kg is circulated to the stage of precipitation of dicalcium phosphate (circulating solution), and 276.2 kg is processed to ammonium nitrate. Get 31 kg of dry washed precipitate of known composition. The removal of a wet non-washed sludge is 4.2 tons from 1 m of filter per hour instead of 1.5 tons, and the yield in the finished product is 74% against 40% by the known method. Example 3. To a 175.5 kg nitrogen 5 phosphate solution prepared in Example 1, a 175.5 kg recycled solution (100% by weight of the ammoniated solution) obtained after separating the finished solution is added.

The Q of the product is neutralized with 38 kg of ammonia to a pH of 1.9 and 5.2 kg of impurities are separated. 383.8 kg of the solution are mixed for 40 minutes with 63.8 kg of calcium nitrate four-fold maintaining the CaO: P ratio, at a stage of 0.75: 1 and 20 kg of ammonia are ammoniated to a pH of 3.5, followed by 7.1 kg. calcium nitrate and 10 kg of ammonia to pH 5.0. The pulp in the amount of 484.7 kg is filtered with

0 release 43 kg of dicalcium phosphate. The filtrate is divided into two streams: 175.5 kg is circulated to the stage of precipitation of dicalcium phosphate (circulating solution), and 266.2 kg are processed to ammonium nitrate. Get 31,5 kg of dry washed precipitate of known composition. Removal of wet, unwashed residue is 5.5 tons with 1 m of filter / hour instead of 1.5 tons,

The yield of PaO5 to the finished product is 75% versus 40% by a known method.

Claims (2)

1. A method for producing feed calcium phosphate by decomposing natural phosphates with nitric acid to cool the nitric acid extract to and separating calcium nitrate from the mother liquor, further processing it with sodium salts and separating sodium silicofluoride, neutralizing the nitrogen phosphate 65 ammonia solution with intermediate separation of impurities and subsequent treatment of the ammoniated solution to a pH of 0. and separation of the feed product, in order to improve the filtering properties of diquitium phosphate and increase the yield of feed stock, the treatment of the ammoniated solution with ammonia is carried out in the presence of working solution in the amount of 15g100% of the mass of ammoniated solution, followed by the supply of calcium nitrate in the amount, providing a ratio of CaO: PdO5 in the pulp of 0.75-0.55: 1. 2. The method of Claim 1, wherein the processing. ammonia is carried out for 20-40 minutes. Sources of information taken into account in the examination 1.Pozin M.E. Technologists of mineral salts, v.2, Himi, 1974, p. 1032-1035. 2. Patent Czechoslovakia 118807, cl. 16.2, 04/27/64.