SU905223A1 - Method for detecting unsoluble precipitate in nitrogen acid decomposition of phosphate feedstock - Google Patents

Description

(54) METHOD OF SEPARATING AN INSOLUBLE RESIDUE

IN NITROGEN ACID DECOMPOSITION OF PHOSPHATE

I

The invention relates to the processing of phosphate raw materials and can be used in the production of mineral fertilizers.

A known method for the production of mineral fertilizers, according to which additives such as ferrous sulphate in the amount of 3.5% of apatite plumb, aluminum sulphate of 1.6%, coarse calcium sulphate of 1.6%, are introduced to improve the filtration of phosphogypsum. The process is carried out at 100 C. and the exposure time of the reagents 1.5 h 1 1.

The disadvantages of this method are the high temperature of exposure of reagents, the maintenance of which is associated with the cost of energy, the duration of the process of exposure ,; which reduces the productivity of the process, the need to introduce different additives, which complicates the process.

Closest to the proposed method to the technical nature of RAW MATERIALS

and the achieved result is a method of separating the insoluble residue in the nitric acid decomposition of phosphate raw materials by introducing an additive into the pulp after decomposition and subsequent filtration, in which liquid glass is used as an additive in an amount of 3-12% of the weight of the L 2 J suspension being processed.

The disadvantage of this method is the need to introduce a large amount of expensive glass and regenerate the latter. Regeneration of liquid glass from an ophthalmic, insoluble residue is a very laborious process, requiring special equipment. In addition, the filtration rate of the impurity sediment does not exceed 14.7- 10 m / m. with .

The purpose of the invention is to intensify the process by increasing the filtration rate. 3 This goal is achieved by the fact that according to the method of separating the insoluble residue during nitric acid decomposition of phosphate raw materials by introducing into the pulp after decomposition of the additive and subsequent filtration, polyelectrolyte is used as an additive: CO-3, 7 1 (G 2410 part by weight of pulp. When polyelectrolyte is introduced into the suspension, the particles are covered with an electrolyte film and coarsened. Polyelectrolyte soda Life%: from 36.57-38.34; N 8.74-9.5; H 6.14-6.18; S up to 1.75. KO-3 is obtained on the basis of bottom residues containing nitrilacrylic acid, by polymerization with subsequent saponification in an aqueous-alcoholic medium in the presence of NaHSO. Polyelectrolyte is introduced into the slurry as a 0.1% aqueous solution. In the table, comparative rates of separation of the insoluble residue are given according to the known and proposed methods.

The separation of the insoluble residue on the suction filter

As can be seen from the table, the maximum filtration rate in the separation of insoluble residue by the proposed method is 6 times higher than by the method with the addition of liquid glass. Going beyond the specified quantitative limit of the input polyelectrolyte dramatically reduces the filtration rate.

Example. In 150 g of pulp obtained as a result of the decomposition of the Fosmuk Karatau by 56% of an empty slot, 2.8 g of a 0.1% aqueous solution of polyelectrolyte is introduced, which is 15.4% by weight of the processed pulp, the mixture nevie-6

0.2-0

stir 5 min at. The separation of the solid phase is carried out using a Buchner vacuum funnel. Filtration time 50 min, filtration rate 32, 1 10.

Carrying out the process according to this method has a significant economic effect, since the cost of KO-3 polyelectrolyte is 6 times lower than the cost of liquid glass.

Claims (2)

Invention Formula The method of separation of insoluble residue with a relative acid razlo59052236 .the phosphate raw materials by typing-Sources of information, neither in the pulp after decomposition are added-taken into account during the examination of ki and subsequent filtration, o whether it is due to the fact that i. Proceedings of the Ural. Scientific Institute for the purpose of intensifying the process at the expense of the Honors Chemical Institute. increase the filtration rate in QA-1973 issue 25 topg ff G polyelec 2. USSR author's certificate 7 FH u-W ™ number№ 650327, cl. From 05 To 11/06, 1980 7-1U 24..h from the weight of the pulp. (published).