RU2186038C2 - Method of treating acidic mine waste waters to remove heavy and nonferrous metals - Google Patents

Abstract

FIELD: waste water treatment. SUBSTANCE: collected acidic drainage water from under mineral refuses, separately or combined with mine water is neutralized to pH 8.0-9.2 by mixing it sludge resulting from washing of ores to remove components of concrete-stowage mix. The thus obtained suspension is settled with height of water layer in accumulation pool about 2 m and sludge is stored in sludge accumulator. Cleaned and clarified water is withdrawn from the surface of sludge accumulator pool. Lime is added to ore washing sludge. EFFECT: simplified process and diminished formation of drainage water and consumption of neutralizers. 1 tbl, 4 ex

Description

 The invention relates to the treatment of industrial wastewater and can be used in mining enterprises of non-ferrous metallurgy.

A known method of purification of acidic wastewater of a mine from heavy non-ferrous metal ions by liming, including collecting drainage water from under a rock dump, supplying them together or separately with mine water to neutralize to pH 8.0-9.2 by mixing with aqueous slurry washing ore from the components of the concrete filling mixture, full filling of the sludge collector, long settling (16 days) at the first stage of the suspension discharged into the first section of the sludge collector, feeding 0.2-0.4 kg / m ^{3 of} lime into clarified water with an increase in pH from 7.5 -8.5 to 9.5-10.0, times Definition resulting suspension in the second slurry tank section clarified water neutralization with sulfuric acid to pH 8.0-8.5 and its discharge into the river. Sediment of the first and second sections of the sludge collector is stored in the first section of the sludge collector. The yield of drainage water to be treated reaches 1200 m ³ / h (see A.M. Kopanev, L.K. Chuchalin. Report on research work "Develop and test geotechnological methods for processing lead-zinc ores at Glavpolymetal enterprises, issue technological regulations for the design of geotechnological complexes ", topic 40-85-239, section 14 (final), volume 1, Novosibirsk, Leninogorsk, 1990, state registration 01880035843, pp. 33-37).

The disadvantages of this method are:
technology complexity, as she is two-stage. In the first stage, in the first section of the sludge collector, prolonged sedimentation of the suspension under conditions of its full filling leads to a decrease in pH due to carbonization and thereby to the reverse dissolution of metal hydroxides and prevents the achievement of the required cleaning depth, therefore, the second stage is carried out in the second section to achieve the desired depth of water treatment ;
the formation of a large amount of drainage water due to the suspension filling the entire volume of the sludge collector and the high consumption of neutralizers for its treatment.

 The basis of the invention is to simplify the process of deep purification of acidic wastewater of mines from heavy non-ferrous metal ions, at the same time reduce the volume of generated drainage water to be treated, and the consumption of the neutralizer for purification by conducting it in one stage and reducing the height of the layer of clarified purified water in the sludge collector .

 This is achieved by the fact that in the known method of purifying acidic wastewater of mines from heavy non-ferrous metal ions by liming, which includes collecting drainage water from a rock dump, supplying them together or separately with mine water for neutralization to pH 8.0-9.2 by mixing sludge from the slurry with water washing the ores from the components of the concrete filling mixture, settling the resulting suspension and storing the sludge in the sludge collector, discharging purified clarified water into the river, according to the invention, the purified clarified water is discharged with surface Prudkyy slurry tank through the outlet in the board at the level of the slurry tank Prudkyy surface. In this case, lime is fed into the slurry pulp of water washing the ore from the components of the concrete mixture.

 This allows you to conduct the process in one stage and thus simplify the process of deep cleaning of acidic wastewater, as well as reduce the formation of drainage water and the consumption of neutralizers for its purification.

 The method is as follows.

 Drainage water from the rock dump is collected and fed together or separately with mine water to neutralize it to pH 8.0-9.2 by displacing them with a slurry of water ore washing from the components of the concrete mixture, then the resulting suspension is settled and the slurry is stored in sludge collector, and purified clarified water is discharged from the surface of the pond of the sludge collector through the outlet in the board at the level of the surface of the pond of the sludge collector. In the flood period, lime is fed into the slurry pulp of water washing the ore from the components of the concrete-filling mixture.

 Patented method tested on an industrial scale.

Example 1. Drainage water from a rock dump in an amount of 200 m ³ / h was supplied to the receiving capacity of the pumping station, where, with two pumps with a capacity of 100 m ³ / h, each of this water was piped to a mixer installed on board the sludge collector at a height 60 m. Then, the slurry pulp of water washing the ore from the components of the concrete-filling mixture from the crushing and beneficiation department in an amount of 200 m ³ / h (8 t / h solid) was pumped through the pipeline to the mixer, where water and pulp were mixed to pH 8.2- 8.6 with mix duration 3 minutes The resulting suspension with a volume of 400 m ³ / h was discharged into the sludge collector and settled for 6 days. A portion of the purified water, equal in volume to the flow of drainage water to the sludge collector (200 m ³ / h), was discharged from the surface of the sludge collector into the river through a pipeline passing through the side of the sludge collector at the level of the surface of the sludge collector pond at a water layer height of about 2 m. The rest of the incoming water (200 m ³ / h) drained through the dump body and turned into drainage water, which was collected and transferred for cleaning in the already described sequence.

 The cleaning results are shown in the table.

Example 2. In the flood period, 400 m ³ / h of drainage water and slurry pulp of water ore washing from the components of the concrete-filling mixture in a volume of 200 m ³ / h (8 t / h solid) were sent for cleaning, lime was added in an amount of 0.3 kg / m ³ drainage water. Water and pulp were mixed to a pH of 9.2. The rest of the method was carried out under conditions analogous to example 1 and obtained similar results.

Example 3. 200 m ³ / h of drainage water, 800 m ³ / h of mine water were sent for cleaning, and they were mixed with 200 m ³ / h of slurry slurry for water washing of ores from the components of the concrete filling mixture (8 t / h solid). The rest of the method was carried out under conditions analogous to example 1 and obtained similar results.

Example 4. During the flood period, 400 m ³ / h of drainage water, 800 m ³ / h of mine water were sent for cleaning and mixed with 200 m ³ / h of slurry pulp of water washing ore from the components of the concrete filling mixture (8 t / h solid), to which 0.3 kg / m ^{3 of} lime was previously added. The rest of the method was carried out under conditions analogous to example 1 and obtained similar results.

Claims (1)

 A method for purifying acidic wastewater of mines from heavy non-ferrous metal ions by liming, including collecting drainage water from a rock dump, supplying it together or separately with mine water to neutralize it to pH 8.0-9.2 by mixing water washing sludge with a pulp ores from the components of the concrete-mortar mixture, sedimentation of the resulting suspension and storage of sludge in the sludge collector, the removal of purified clarified water into the river, characterized in that the sedimentation of the formed suspension is carried out at a height of the water layer in the sludge collection pond Itel is about 2 m long, and the purified clarified water is discharged from the surface of the pond.

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