SU1449594A1 - Method of processing phosphorus-containing slurry - Google Patents

Abstract

The invention relates to the processing of phosphorus sludge and allows to simplify the processing of phosphorus sludge while maintaining a high degree of phosphorus recovery. The method includes the electrochemical oxidation of phosphoric sludge in a solution of phosphoric acid with stirring. The process is conducted with alternating current of industrial frequency on electrodes from copper, titanium and titanium at a current density of 50-170 kA / m. Table I

Description

ate

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: The invention relates to the processing of waste from the chemical industry. - phosphorus sludge, in particular to copper phosphide |

I The main disadvantage of the well-known specialist is the use of stationary current, which requires the introduction into the technological scheme of a deficit worth-of-charge equipment — a rectifier of current. Use of rectifier | In turn, it requires additional premises and maintenance staff. All of this generally complicates the recycling process.

pit sludge,

1449594

In the sediment elemental phosphorus is missing. The electrolysis product is copper phosphide and phosphoric acid,

The table shows the effect of the current density on the titanium electrode on the residual content of elemental phosphorus in the phosphorus sludge.

ten

15

thirty

Fs | . .

The purpose of the invention is to simplify the process of processing, phosphorus sludge maintaining a high degree of phosphorus recovery from sludge.

I The essence of the method is. next.

At certain optical current densities (150-160 kA / m), a 25 Å .1 level of dissolution of the copper electrode is created on the titanium electrode with the alternating current to form bivalent copper, which interacts with the elemental phosphorus present in copper phosphide and phosphoric acid.

A distinctive feature of the method is an electrochemistry. of the industrial process of recurrent valuation, 35

I The process conditions are selected on the basis of experimental data. When-> nickel, stainless steel, copper, aluminum and others as the second electrode does not add to the expected positive effect, the use of titanium elec- trod makes it possible to find the optimal conditions for the processing of phosphoric sludge with a bore current, 45

The method is carried out in a thermostatted glass cell with mixing,

 Example. The initial amount of phosphorus in the sludge is 1 g, the volume of electro-JQ is 400 MP (H, PO4 100 g / l), the current density on the copper electrode is 200 A / m. A titanium electrode is used as the second electrode. The current density at the titanium electrode is 55–160 kA / m. The duration of the electrolysis is calculated according to the Farad law for one half-period of alternating current and is given by a 20% excess.

As can be seen from the tapestry, the optimum alternating current density on the titanium electrode is 50-kA / m, preferably 150-160 kA / m,

The choice of the current density range on the titanium electrode is due to the fact that during the polarization of titanium by alternating current at relatively low current densities in acidic solutions, it dissolves very intensively. This is due to the fact that in the cathode half-period, the titanium oxide film is reduced to elemental titanium and, in the anode sub-period, is intensively dissolved (with a current output of 30–60%) as an electronegative metal. Thus, it does not have time to form a dense oxide on the film and, as a result, a positive effect is not achieved. During the processing of phosphoric-sludge at a current range of 50-170 kA / m, the dissolution of titanium practically ceases and at the same time an oxide is formed on the film with valve

As can be seen from the tapestry, the optimum alternating current density on the titanium electrode is 50-kA / m, preferably 150-160 kA / m,

The choice of the current density range on the titanium electrode is due to the fact that when titanium is polarized with alternating current at relatively low current densities in acidic solutions, it dissolves very intensively. This is due to the fact that in the cathode half-period the titanium oxide film is reduced to elementary titanium and, in the anode sub-period, is intensively dissolved (with a current output of 30-60%) as an electronegative metal. Thus, it does not have time to form a dense oxide film and, as a result, a positive effect is not achieved. During the processing of phosphoric-sludge at current densities of 50-170 kA / m, the dissolution of titanium practically ceases and an oxide film is formed instantaneously, which has a valve

314495944

property that allows to achieve the oxidation of phosphorus sludge into a solution-positive effect. Phosphoric acid while mixing. Thus, when using a copper electroplated method, the process of microprocessing, characterized in

This is due to the use of variable-what, to simplify the process when

industrial current, together with rectifying-retaining a high degree of extracted direct current. This is to exclude phosphorus from sludge, electrochemical use of expensive delicate treatment is carried out by alternating current of cyttic equipment - rectifier. industrial frequency when using Formula nzob, retention of the second material

A method of processing phosphoric slag titanium electrode and current density on

ma, including electrochemical; 50-170 kA / m.

Claims (1)

Claim A method of processing phosphorus sludge, including electrochemical; oxidation of phosphorus sludge in a solution of phosphoric acid with stirring using a copper electrode, characterized in that, in order to simplify the process while maintaining a high degree of phosphorus extraction from the sludge, the electrochemical treatment is carried out by an alternating current of industrial frequency when using the second electrode as titanium and current density on it 50-170 kA / m ² .