RU2625102C1 - Method of extracting the contaminated white phosphorus - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method is carried out by pumping water, heated to 65-70°C, along the outer lumen of a double-lumen flexible hose into a container of contaminated white phosphorus. At the same time, white phosphorus melts upon mixing with water and turns into a water-phosphorus suspension. At the same time, the resulting water-phosphoric suspension is sucked into the storage part of the pump, where the phosphorus-containing suspension is cooled, the white phosphorus crystallises and precipitates.

EFFECT: increasing the efficiency of recovery of white phosphorus contaminated with sludge for utilisation, ensuring environmental safety and the ability to extract white phosphorus contaminated with different types and sizes of pollutant particles from storage sites.

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Description

Application area

The invention relates to a technology for processing and disinfecting phosphorus sludge and can be used in the chemical industry for the disposal of contaminated white phosphorus, its cleaning from mechanical pollutants.

Analogs:

A known method for the extraction of phosphorus from sludge // SU 1518296. The essence of the invention lies in the sorption of drops of molten phosphorus by contact with the sorbent.

The disadvantages of this method are the need to use a significant amount of sorbent and the inability to completely remove phosphorus from the sludge, as well as the need to extract phosphorus from the mass of the sorbent, a multi-stage process, contamination of the extracted phosphorus with associated substances.

Similar in technical essence to the proposed is a method of extracting phosphorus from sludge by treating sludge with 5-30% nitric acid with a mass ratio of sludge and acid 1: (0.6-1). The disadvantage of this method is the impossibility of extracting phosphorus from “sludge poor in phosphorus” containing 3-20% phosphorus due to oxidative processes occurring between nitric acid and associated impurity substances, as a result of which carbon and phosphorus float to the surface. Foaming and combustion of phosphorus occurs.

Prototype

As a prototype, we took a method for extracting phosphorus from sludge // SU 1518296. The essence of the prototype method is to sorb drops of molten phosphorus by contact with a sorbent.

Prototype criticism

The disadvantages of the prototype method are: the use of a significant amount of sorbent and the impossibility of complete extraction of phosphorus from the sludge, as well as the need for further extraction of phosphorus from the mass of the sorbent, a multi-stage process, contamination of the extracted phosphorus with associated substances.

The purpose of the invention is a method is to increase the efficiency of the method of extraction of white phosphorus contaminated with sludge for disposal, ensuring environmental safety, economic benefits, the ability to extract white phosphorus contaminated with various types and sizes of pollutant particles from their storage sites.

The essence of the proposed method

The method proposed as an invention is as follows: water heated to 65-70 ° C is supplied through the outer lumen of a double-lumen flexible hose to a container with contaminated white phosphorus. In this case, locally, at the place of arrival of the stream of heated water, white phosphorus melts, mixes with water and turns into a water-phosphorus suspension, at the same time, the resulting water-phosphorus suspension is sucked into the storage part of the tank, then the water-phosphorus suspension is cooled, the phosphorus crystallizes and precipitates to sediment.

The proposed method is based on the following properties of white phosphorus:

Allotropic modification of elemental phosphorus - white phosphorus melts at a temperature of 44.1 ° C, boils at 280.5 ° C. Of all allotropic modifications, white phosphorus has the lowest density (1.8 g / cm ³ at 20 ° C). Technical white phosphorus (yellow phosphorus) is an amorphous, beeswax-like mass of yellowish or light brown color. White phosphorus is extremely flammable. In the presence of atmospheric oxygen, white phosphorus is easily self-igniting. The auto-ignition temperature of white phosphorus is around 30 ° C. The combustion of white phosphorus is accompanied by the formation of phosphorus oxide P ₂ O ₅ and the release of a large amount of heat. The calorific value of white phosphorus is - 24000 J / g. Phosphorus pentoxide is a hygroscopic substance that absorbs moisture from atmospheric air and forms orthophosphoric acid H ₃ PO ₄ . The formation of acid mist makes ignition of phosphorus even more dangerous. To prevent uncontrolled oxidation and fire, white phosphorus is stored under water, with which it practically does not react. During long-term storage in open containers, the waste products of the chemical production of phosphorus compounds and phosphorus-containing sludge are gradually contaminated by foreign objects and dirt particles, which themselves become flammable due to sorption of white phosphorus particles, which complicates the extraction of contaminated white phosphorus for its further processing and disposal. Moreover, in the southern regions, at high ambient temperatures, especially in the summer, there is a partial melting of white phosphorus. Due to its high density, molten phosphorus as an easily flowing substance fills irregularities and crevices at the bottom. To implement the proposed method for extracting white phosphorus, a device was assembled in the form of a double-sided pump, a diagram of which is shown in FIG. 1. The device is a 150 ml plastic cylinder (pos. 1) hermetically sealed on both sides with fluoroplastic plugs, inside which the fluoroplastic piston (pos. 2) moves with the help of a rod (pos. 3) passing through the fluoroplastic plug (pos. 8 ) The piston cylinder is divided into two compartments (items 4 and 5) with outlet openings (items 6 and 7), to which a double-lumen flexible hose is connected. The bends of the cylinder are connected with a double-lumen flexible hose so that the outlet of the pump compartment (pos. 7) is connected to the inner lumen, and the outlet of the compartment (pos. 6) is connected to the outer lumen of the hose. To implement the proposed method by moving the piston, the cylinder is filled with water heated to 65-70 ° C.

The free end of the double-lumen flexible hose is lowered to the bottom of the tank with white phosphorus contaminated with mechanical impurities. Gradually, by moving the piston, heated water from the pump compartment pos. 5 is pushed into a container, white phosphorus melts, under the influence of water pressure it mixes with heated water and an aqueous-phosphorus suspension is formed. As water is pumped out, another pressure is created inside another pump compartment (key 4), which leads to the suction of the water-phosphorus suspension into the cylinder by the internal hose (key 4).

Due to the double-lumen design of the hose due to the heat exchange of the external and internal gaps through the wall of the internal hose, high water temperature is kept in the pipeline and the phosphorus inside the hose remains liquid.

Example 1. In a round bottom flask under a layer of water with a volume of 15-20 ml is placed 2 g of white phosphorus. The white phosphorus extraction pump is filled with water heated to 65-70 ° C. The free end of the double-lumen hose is released to the bottom of the bulb. Gradually, from one compartment, the piston pushes water into the flask. Under the action of heated water, phosphorus melts and the resulting water-phosphorus suspension is sucked into the other compartment of the cylinder by an internal hose.

Example 2. It is carried out in the same way as the first example, but with the following difference: mechanical impurities in the form of crushed stone from crushed rock are added to the contaminated white phosphorus in the flask. Molten white phosphorus and finely divided particles of crushed rock are absorbed into the cylinder.

Features of the invention, distinctive from the prototype

Prototype:

1) the use of a significant amount of sorbent,

2) the need for further extraction of phosphorus from the mass of the sorbent,

3) multi-stage process

4) the contamination of the extracted phosphorus associated substances,

5) sorption of drops of molten phosphorus occurs by contact with the sorbent.

Invention

1. Water heated to 65-70 ° C is supplied through the outer lumen of the double-lumen flexible hose into a container with white phosphorus contaminated;

2. At the place of arrival of the stream of heated water, white phosphorus melts, mixes with water and turns into a water-phosphorus suspension, while the resulting water-phosphorus suspension is simultaneously sucked into the storage part of the tank;

3. Then the aqueous-phosphorus suspension is cooled, the phosphorus crystallizes, precipitates.

The positive effect of using the proposed method

The positive effect of the application of the proposed method is to increase the efficiency of the method of extracting white phosphorus contaminated with sludge for disposal, ensuring environmental safety, achieving significant economic benefits, the possibility of extracting white phosphorus, contaminated with various types and sizes of pollutant particles, from its storage sites, the simplicity of the method .

Information taken into account:

The method of extraction of phosphorus from sludge // SU 1518296 - prototype.

Claims (1)

A method for the extraction of contaminated white phosphorus, characterized in that water heated to 65-70 ° C is pumped into a container with a contaminated white phosphorus pump through the outer lumen of a double-lumen flexible hose, while the white phosphorus melts, mixes with water and turns into water-phosphorus suspension, at the same time, the resulting water-phosphorus suspension is sucked into the accumulation part of the pump, where the phosphorus-containing suspension is cooled, white phosphorus crystallizes and precipitates.

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