SU1286511A1 - Method of extracting phosphorus from kiln gas - Google Patents

Abstract

This invention relates to the technology of electrothermal phosphorus production. The preliminary separation of the condensate formed at a temperature of 1.5-4, below the phosphorus dew point, simplifies the process by eliminating the phosphorus purification stage by filtration. Phosphorus-containing furnace gas with a temperature of 320 ° C in an amount of 3500 nm with a content of 5.2% (volume) of phosphorus and 57.1 g / nm of dust with the electric filter switched off is passed through an external cooling pipe system, while cooling is conducted in such a way that the outgoing phosphorus-containing gas has a temperature and the phosphorus content in it is 4.7% or 90.0% of the initial gas. 273.6 kg of condensate containing 26.9% of phosphorus and the rest are mineral impurities flow into the condensation bath . Then the gas enters stage II, where the phosphorus is condensed by feeding water into the gas, reducing its temperature to. In the collection, 917.1 kg of phosphorus is obtained with a benzene insoluble residue content of 0.22%. The condensate from stage 1 is sent to the production of sludge phosphoric acid, the phosphorus condensed in stage II is used without additional sludge and filtration, table 2. (L

Description

12

The invention relates to the technology of electrothermal production of phosphorus, in particular to the extraction of phosphorus from the exhaust gases of phosphoric furnaces,

The purpose of the invention is to simplify the process by eliminating the stage of phosphorus purification by filtration,

The method is carried out as follows.

Example 1. Phosphorus-containing furnace gas of phosphoric furnaces operating on lumpy phosphate with 3500 in content with a content of 5.2% by volume of phosphorus and 57.1 g / nm of dust, with the electrostatic precipitator off, is passed through a system of pipes with external cooling, while cooling lead in such a way that the output phosphorus-containing gas has a temperature of 177, the phosphorus content in it is 4.9%, or 94% of the original, the dew point of phosphorus is equal. Under a layer of water, 253.6 kg of condensate containing 20.9% of phosphorus flows into the condensation bath and the rest is mineral impurities. During the condensation of phosphorus from a dusty phosphorus-containing gas stream using external cooling, the solid portions of the gas present in the gas are well wetted with liquid phosphorus; the wetting angle is 59. When the gas flow temperature decreases by 1.5-4, 5-10% of the phosphorus of the total amount contained in the gas condenses below the dew point, while the condensed phosphorus removes a significant amount of mineral and gas from the gas stream. organic impurities. Contaminated phosphorus, -co-containing up to 80% of solid impurities, comes from the process (it can later be used in the production of sludge phosphoric acid). Then the gas enters the 11th stage where the phosphorus condensation is carried out by supplying water to the gas, lowering its temperature to. In this case, 938 kg of phosphorus is obtained in the collector with a residue insoluble in benzene 0,

The condensate from the 1st stage is directed to the production of sludge phosphate.

fo

651

five .

35%.

fororic acid, phosphorus condensed in the 11th step, is used, without additional sludge and filtration,

Table 1 shows comparative data on the purity of phosphorus obtained at the stage of condensation according to the proposed and known methods.

Table 1

Gas temperature at entry from systems dry

condensation in the wet.

 WITH.

about 180 (depending on the dew point) 60

The degree of condensation of phosphorus in the dry degree,%

5-10

95-97

up to 75

10-15

The degree of condensation of phosphorus in the wet stage. %

90-95

3-5

The quality of phosphorus formed in the wet stage (n, o,%)

0.1-0.3

0.1-0.3

Table 2 shows the process performance versus temperature at which the condensate formed was separated.

5.2

When working on lumpy phosphate 179 178.5 0.5 99

Delivered

the goal is reached. Need to filter phosphorus

When working on sinter

Claims (1)

Claims: what, in order to simplify the method 9a The method of extracting phosphorus from the furnace — excluding the stage of purification of phosphate gases, including their cooling of the forehead by filtering, preliminarily separates the condensate formed at the temperature below the dew point of the phosphorus, the formed head and collecting the condensed pro- at: at a temperature of 1.5-4.5 With the product below, characterized in that the POSE points of phosphorus.