SU973479A1 - Process for purifying effluents from arsenic - Google Patents

Description

(54) METHOD FOR CLEANING SEWAGE WATER FROM MESHIAK

The invention relates to methods for the treatment of waste water from a mouse, and can be used in non-ferrous metallurgy and the chemical industry, in particular for the removal of arsenic selenium acid and weakly alkaline solutions from the mouse.

A known method of cleaning wastewater from mice containing milligram quantities (50-100 mg / l) of this element by treating them with iron-containing materials, such as red mud (waste from alumina production according to Bayer method) 1.

The disadvantage of this method is the impossibility of complete sedimentation of the mouse from solutions containing 100 mg / l of milk, which necessitates a special preliminary preparation of solutions (neutralization, partial precipitation of calcium oxide) and subsequent relatively labor-intensive operations (repulping red amtam, agitation , pulp filtration, etc.).

There is also known a method for treating wastewater from small amounts (less than 100 mg / l) of a mouse by treating them with calcium hydroxide and phosphoric acid. According to this method, with a flow rate of 8.5 kg / m3 of 5% milk of lime and 0.5 kg / m of 54% (by) phosphoric acid in the filtrate, the maximum permissible concentration is reached for mouse 2.

The disadvantages of this method are the impossibility of cleaning the mouse to the sanitary standard of wastewater containing more than 100 mg / l of the mouse, and

10 also uses expensive phosphoric acid.

Closest to the invention of the technical essence and the achieved result. is a cleaning method

15 waste water from the mouse, which includes treatment with magnesium compounds (oxide and magnesium chloride) at 1825 C 3.

20

This method ensures the cleaning, for example, of alkaline weft-out containing 0.5-3.0 g / l m1LDP. ka and 4-10 g / l of caustic soda, with a six-fold excess of magnesium chloride to

25 mouse concentrations of 100 mg / l. However, the known cleaning method does not allow to reduce the content of the mouse in the wastewater to the sanitary standard. The aim of the invention is to increase the degree of purification.

This goal is achieved by the fact that according to the method of wastewater treatment from the mouse, which includes treatment with their magnesium compounds at 18–25 ° C, as the magnesium compounds, the Karn slimes of a 1-liter chlorinator 5 are used at the weight ratio of sludge to juice (10-12) : 1 and pH 6-8.

The method consists in the fact that when treating sewage with carnetshitic sludge chlorine from magnesium sulphate produced (Ust-Kamenogorsk Tytan-magnesium plant), for example, of the following composition g-%: MdSTs 19.3 / MgD 19.7 / NaCl 19, 9; KCl 20.0; CAS 0,83; Ti 1,1-Si 0,36; Al 0,13; 15 C 1,3 The formation of the hardly soluble basic magcomnut arsenate occurs

 I I - I I

5.5 I I I I

 f I

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6.0 The results of experimental data show that deviations from optimal conditions (weight ratio of slurry to mouse 10–12: 1, pH 6–8, t 18–25 ° С, T 3-4 h) lead to incomplete deposition of the mouse from the solution. I Example. 100 ml of spent selenium solution containing L., - g / l: 56; Se 24.5 Te 0.9 / As 6.8J Pb 0.5; NaOH 44; Neutralize with sulfuric acid to pH 8. After filtration and separation of selenium, a solution containing 5.9 g / l of As is treated with 12 g of carbon-sulphate magnesium chloride produced in a commercial tetrapure and agitated for 4 hours. detected.

nor, by virtue of which, you can remove the mouse from the solution.

With a weight ratio of sludge to mouse equal to (10–12): pH of a medium 6–8 and a temperature of 18–25 ° C for 3–4 h, mouse K is almost completely precipitated by sludge.

The resulting sediments can be stored directly in the tailings, and the solutions are discharged into open water bodies or used for technical needs. The method was tested on industrial selenium solutions of the plant Uralelectromed.

The results of mouse sedimentation with carnallite chlorinator of magnesium production are presented in the table.

4.3

1.9 0.3 0.04 Footprints

Not detected. II Example 2. 100 ml of a waste solution of a slurry workshop containing 90 g / l of a mixture of sulfuric and hydrochloric acid, 4.8 g / l As are treated with 2 g of carnallite chlorinator sludge at pH 6, temperature 20 ° С and stirring during 3h After processing in solution, the mouse was not detected. The technical and economic effect of the proposed method is due to the fact that the method allows to purify waste water and industrial solutions with a higher content of the mouse to the sanitary standard and is more economical since it involves the use of cheap materials from carnallite chlorinator, which is a waste of magnesium production.

invention formula

The method of treating wastewater from vibniiblKa, which includes treating them with magnesium compounds at a temperature of 1825 ° C, characterized in that, in order to increase the degree of purification, carnallite chlorinator sludges are used as magnesium compounds (10-12) : 1 and pH 6-8.

Sources of information taken into account in the examination

1, Non-ferrous metals, 1972, 1, p. le.

2. Non-ferrous metals, 1978, 1, p. 30-32.

3 .. Serova V.A., Kogan B.I. Methods of wastewater treatment and technological solutions from the mouse. Overview information. M., MKM USSR ,. 1977,

with. 8-9.

Claims (1)

Claim A method of treating wastewater from arsenic, including treating them with magnesium compounds at a temperature of 1825 ° C, characterized in that, in order to increase the degree of purification, carnallite chlorinator sludges are used as magnesium compounds at a weight ratio of sludge to arsenic (10-12) : 1 and pH 6-8.