SU865786A1 - Method of phosphorus extraction from slime - Google Patents

Description

(54) METHOD FOR EXTRACTING PHOSPHORUS FROM SLIM.

one

The invention relates to the production of phosphorus and can be used for the processing of phosphorus sludge.

A known method for the purification of crude phosphorus by halogen-substituted organic compounds is as follows. Phosphorus contaminated with mechanical and organic impurities is intensively mixed with the organohalide compound at a temperature above the melting point of phosphorus, followed by separation of the mixture into three phases: upper - aqueous with mechanical impurities, medium - organohaloids and lower - purified phosphorus 1.

The disadvantage of this method is the low recovery of phosphorus (29-32%) from sludges containing 3-40% phosphorus.

There is also known a method of extracting phosphorus from sludge: containing 3-40% phosphorus, by treating them with a mixture of organochlorine reagent and hydrogen peroxide at 50-60 s, vigorous stirring and weight ratio of organochlorine reagent, hydrogen peroxide and phosphorus, equal cml (8-10) : (0.02-0.05): 1. The degree of phosphorus recovery is 80-85% 2.

The purpose of the invention is to improve the degree of extraction of phosphorus from the sludge.

The goal is achieved by the fact that phosphorus-containing sludge is treated with a mixture of organochlorine compound and nitric acid or solutions of its salts at a weight ratio of organochlorine compound: HNOj (solution of its salt): P (7-8):, (0.05-0.07) :one.

When this happens destruction

15 slurry structure and pure phosphorus is discharged. The degree of phosphorus recovery is 87-91%. Ammonium, alkali and alkaline salts of the earth are used as salts of nitric acid.

The choice of the optimal parameters of the process is due to the fact that with the weight ratio of organochlorine compound to phosphorus

25 (7-8): 1 degree of phosphorus recovery is 87-91%. The decrease in chloroform compound consumption leads to a decrease in the output of pure phosphorus, and an increase does not affect its

30 exit.

The optimal ratio of HNO (solution of its salt): P is the weight ratio (0.05-0.07): at which the recovery of phosphorus is quite high (86-90%). Reduced nitric acid consumption

(a solution of its salt) leads to a decrease in the yield of pure phosphorus due to the low efficiency of the oxidation process by JC, and an increase in its consumption reduces the yield of phosphorus due to the oxidation of a part of it to phosphoric acid. Due to the fact that phosphorus-containing sludges are acidic

(), the degree of extraction of phosphorus from them does not change when replacing nitric acid with solutions of its salts.

When processing sludge with a mixture of SS d-NYOA

When processing the sludge mixture As can be seen from the table. , for the optimal ratio organochlorine compound: phosphorus, the ratio (7-8): can be taken, since when this is achieved a sufficiently high degree of phosphorus recovery (87-88% when the sludge is treated with the mixture when the sludge is treated with the CHC mixture CCl2-HNO. Example 2. B 56.7 g of sludge with a content of 9% is placed at the reactor temperature.

When treating sludge with a mixture of SS and HNO

When processing sludge with a mixture of SNS CC and HNO

As can be seen from the table. 2, the optimal ratio of%: HNO is: (0.05-0.07). In this case, a sufficiently high degree of phosphorus recovery is achieved (87-88% when treating the sludge with a mixture of CC14 and 86-90% when treating the sludge with a mixture and HNOj).

Example 3. In a thermosetted reactor were placed 3.4 sludge with a content of 9%. When mixing, served in the editor

Example. 67 g of sludge containing 38.74% of phosphorus are placed in a temperature-controlled reactor. With stirring, trichlorethylene or CC and 4 cm of 65% HNO are simultaneously fed into the reactor. The weight ratio is 0.05 :. Stirring is carried out for 0 minutes, after which the reaction is allowed to stand. the mixture until complete separation of the phases, the phosphorus is drained and weighed.

Data on the effect of the amount of organochlorine on the degree of phosphorus recovery are presented in Table. .

Table

73, 86.9 88.4 89.2 89.0 8.2 9.4 89.9 89.7 90.0

32.5 82.7 88.4 87.3 80.8 33.0 84.4 89.9 86, 82.4

at the same time, 262 g of trichlorethylene and 2.1 g of HNO-j, dissolved in 5 ml of water. The balance is the ratio of the trichlorethylene: HNO ,, reagents: 05: (recalculation of the salt provbd t to free acid). Stirring is carried out for 0 minutes, after which the reaction mixture is allowed to stand until complete separation of the phases. Phosphorus is drained and weighed. 29.9 g of P are obtained, and the phosphorus yield is 9.2%. A similar effect is achieved by "stirring the arms in the reactor at the same time with HNO and 1-3 g of trichloroethane or CC14 (weight ratio of chlorine is 8). Chemical compound. Stirring is carried out for 0 minutes, after which the mixture is left to settle the reaction mixture until complete separation of the phases. Phosphorus is poured and weighed. The dependence of the degree of phosphorus recovery on the weight ratio P4: HNOj is presented in Table 2. Table 2

use of salts of alkali and alkaline earth metals of nitric acid.

Claims (2)

1. US Patent 2123554, K) I.23-223, 1978.. 2. USSR author's certificate 0 on application 2721199 / 23-26, cl. From 01 to 25/01, 1979.