SU1017670A1 - Method for recovering phosphorus from phosphorus production furnace gas - Google Patents

Abstract

A method of extracting phosphorus from the gases of the furnaces of phosphorus production, including two-stage cooling of gases with water, collecting condensed phosphorus and separating it from the sludge, characterized in that, in order to reduce the amount of sludge and the phosphorus content in it, before cooling, the gases are treated for 0.15- 2 with water vapor with a temperature of 140-350 ° C supplied in an amount of 10-100 g / m of gases. §

Description

ABOUT)

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o The invention relates to the technology of electrothermal production, in particular, to the extraction of phosphorus from the exhaust gases of phosphoric furnaces. A method is known for extracting phosphorus from gases of phosphorus production furnaces (5 pores of their irrigation with liquid phosphorus. At that, the temperature of irrigating phosphorus is chosen based on the conditions of minimal fogging 1.3. The method to extract phosphorus from waste products is the closest to the invention in terms of technical nature and the achieved result. gases of phosphoric furnaces by cooling these gases with water, while at the first stage of condensation there is a sharp cooling of gases from up to 55-b5 ° C, which leads to the intensive formation of phosphorus mist. The mist, phosphorus occurs at the centers, which is dust, always present in exhaust gases 6. At this stage, the main amount of phosphorus is released, then the pre-cooled gases are fed to the second cold condensation stage, operating at a temperature below the melting point of ffsor. Phoefo (and sludge is collected in tanks where phosphorus sedimentation and sludge separation occurs: I 3 The disadvantages of the known method are a significant amount of sludge and a relatively high the concentration of phosphorus in the sludge, the amount of flam is, and the content of phosphorus in it is 70-72. The aim of the invention is to reduce the amount of sludge produced and reduce the phosphorus content of the sludge. The goal is achieved by the fact that according to the method of phosphorus extraction from the flue gases of phosphoric furnaces involving two-stage gas cooling with water, collection of condensed phosphorus, and separation of phosphorus from phosphorus sludge, the flue gases are treated with water vapor at T O- before Cooling 350 ° C for: 0.15–2 s, with water vapor feeding in the amount of 10–100 g / m of exhaust gases. Pretreatment of furnace gas with steam allows reducing the amount of sludge to 20 and its phosphorus content to 57-58%. EXAMPLE 1. In a type electro furnace with an installed capacity of 48 mVA, the Kara-Tau phosphorite ore is reduced. The furnace operates at a power of 35 mVA on one electrostatic precipitator-phosphorus capacitor system. This produces 9,000 gases with a temperature of 260 ° C, containing 300,350 g / nm of phosphorus and 80 g / nm of Dust. The flue gas from the phosphate furnace is exposed. They are cleaned in an electrostatic precipitator to a dust content of 1.5-2.5 g / nm. The gases leaving the electrostatic precipitator are subjected to steam treatment at temperatures of l40 ° C. Steam is supplied in the amount of 100 g per 1 m of waste gases, the treatment time is 0.2 s. After the steam treatment with steam, the waste gases are cooled with circulating water to 55-65 ° C. Condensed phosphorus is collected in a container and settled. Cooling gases up to 55 b5C at the second stage are subjected to additional cooling to 20-30 ° C for more complete extraction of phosphorus. The amount of sludge produced is 22%, while the composition of the sludge is as follows:% Rd - 59.7; solid phase -1,9. EXAMPLE 2. In an electric furnace: of the type RKZ-48f with an installed capacity of 48 mVA, the Kara-Tau phosphate ore is restored. The furnace operates at a power of 35 mVA on one electrostatic precipitator-phosphorus capacitor system. At the same time, 9000 gas arises with a temperature of 2 0 O ° C, containing 300-350. g / nm of phosphorus and 80 g / nm of dust. The flue gases of the phosphorus furnace are cleaned in an electrostatic precipitator. dust content 1.5-2.5 g / nmL The gases leaving the electrostatic precipitator are subjected to steam treatment at a temperature of 200 ° C. Steam is supplied in the amount of 25 g per 1 m, the treatment time is 0.2 s. After steam treatment, the exhaust gases are cooled with circulating water to 55-b5 ° C. Condensed phosphorus is collected in a container and settled. The gases cooled to 55-65 ° C are not subjected to a second stage to additional cooling to 20-30 ° C in order to extract phosphorus more completely. The amount of sludge formed is 22, its composition is as follows,%: P -63.8; solid phase -1.8. Froze In an electric furnace of the type RKZ-48f with a 48 mVA suctored power of 48 mVA, Kara-Tau phosphate ore is being reduced. The furnace operates at 35 mVA on one system

electrostatic precipitator-phosphor capacitor. This produces 9000 cm of VM gas with a temperature of 2 W O ° C, containing 300–350 g / nm of phosphorus and 80 g / nm of dust. The flue gases of the phosphorus furnace are cleaned in an electrostatic precipitator to a content of 1.5-2.5 g / nm dust. Waste up to 55-65 ° С. Condensed phosphorus is collected in a container and settled. Cooled to 55-b5 ° C, the second stage is subjected to additional cooling to 20-30 ° C in order to extract phosphorus more completely. The amount of sludge formed is 21%, its composition is barely 510176706

As can be seen from the table, the optimum 5-7 and the content of the solid phase in 2 is the following processing mode: 2.5 times due to its removal from the temperature of the water vapor 1 0-350 ° C; waters, as well as to increase the output of the cooking time of 0.15–2 s; phosphorus from the resulting sludges per

Steam consumption 10-100 g / m waste s.

gases ...

Thus, the proposed method. The economic effect of the use of the invention makes it possible to reduce the amount of treatment of the invention with the thickness of the sludge produced by 1.5-2 times, a decrease in phosphorus of 100 thousand tons per gram of 5-fold phosphorus content in the sludge by about J million rubles. .

Claims (1)

METHOD FOR REMOVING PHOSPHORUS FROM GASES OF OVEN PRODUCING PHOSPHORUS, including two-stage cooling of gases by water, collection of condensed phosphorus and its separation from sludge, characterized in that, in order to reduce the amount of sludge and its phosphorus content, the gases are processed for 0 , 15-2 with water vapor with a temperature of 140 ~ 350 ° C, supplied in quantity 10-100 g / m ^{e of} gases. a * m 1 1017670-2