RU2535048C2 - Method of extraction of saponite-containing substances from return water and device for its implementation - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to the mining industry and can be used to extract fine saponite-containing suspended solids from discharging tailing pits of return water. The return water is exposed with electric shock in the container of the electrically conductive material in the form of a bath 4 serving as a cathode. In the bath 4 the rotary drum 1 is half submerged, that serves as an anode. The voltage of 30 to 36 V is supplied to the electrodes. The frequency of rotation of the drum 1 is set from 10 to 20 min^-1. Extraction of saponite-containing substances is carried from the surface of the drum 1 continuously with a scraper 6. The return water containing saponite-containing substances is fed into the bath 4 in the direction of the drum 1 rotation.

EFFECT: invention enables to reduce the content of saponite-containing substances in return water to the level of water quality of return water supply of the concentrating mill with purity degree of more than 88%.

2 cl, 7 dwg, 1 tbl

Description

The invention relates to the mining industry and can be used to extract finely dispersed saponite-containing suspended solids from recycled water, draining tailings, etc.

A known method of cleaning solutions from suspended (including clay) particles, in which the wastewater is settled, is then filtered through granular graphite material with a degree of angularity of 200-400 m ^-1 placed between the cathode and anode. The current density is maintained within 20-50 A / m ² [Patent RU 2038319, cl. C02F 1/46, publ. June 27, 1995].

A known method of wastewater treatment, in which wastewater with pre-introduced air oxygen through a dispersant in the form of a porous septum is passed through a load of a mixture of iron chips with activated carbon granules while the electric current is applied to water from an external source to an additional anode made in in the form of a steel rod placed in the load and isolated from it by a perforated pipe of dielectric material, and a housing made in the form of a cathode [Paten RU 2057080, Cl. C02F 1/46, publ. 03/27/1996].

A known method of purifying a liquid from suspended and colloidal impurities, in which it passes through a series-installed electrolyzer, flotator and filter [Patent SU 1761676, class. C02F 1/00, publ. September 15, 1992].

A known method of dewatering sludge sludge, including its processing in a diaphragm electrolyzer in the region of the positive electrode, followed by separation into a condensed product and clarified liquid. The processing of the precipitate is carried out at pH 1-4 at an electric current density of 1-3 - mA / cm ² for 0.5-2.0 hours, then saturated with air under pressure, then the separation is carried out by flotation [Patent RU 2006477, CL. C02F 1/46, publ. 01/30/1994].

The closest analogues in technical essence and the achieved result for the claimed method of extracting saponite-containing substances from recycled water and device are a method and device for intensifying the process of de-slamming of recycled saponite-containing water [article: V.A. Chanturia, B.E. Goryachev. Enrichment of diamond-containing kimberlites. Mining Journal, 2007, No. 2, pp. 43-44]. The method includes treating the circulating water with electric current in a device, followed by separation into a condensed product and clarified liquid. The method is based on the recharge of mineral particles in contact with the anode surface with the aim of their subsequent coagulation (enlargement). The device includes a plate monopolar electrolyzer without diaphragm type.

The disadvantages of the specified method and device are:

1. The method does not immediately allow the separation of saponite-containing water into a condensed saponite-containing product and clarified discharge, but only intensifies the subsequent process of dehumidification of circulating saponite-containing water: the content of sludge in recycled water, depending on the duration of the subsequent clarification process after preliminary electrochemical treatment of water, decreases by 1.6- 5.6 times.

2. The design of the electrolytic cells is not intended for the treatment of waters with a high (more than 50 g / dm ³ ) concentration of the solid phase, as this results in the overgrowth of the anodes made in the form of plates with fine mineral particles, which leads to the failure of the electrolytic cells.

3. The low content (less than 240 g / dm ³ ) of the solid phase in the sediment after the clarification process, as well as its high content in clarified discharge (3-12 g / dm ³ ) with a low content of sludge in the source water, i.e. low degree of purification.

All of the above methods and devices for treating industrial waters containing finely divided suspended solids do not allow saponite-containing substances to be extracted from the circulating waters while obtaining a clarified discharge and are unsuitable for treating waters with a concentration of clay particles up to 257 g / dm ³ .

The aim of the invention is to extract saponite from recycled water and tailings dumps and to increase the degree of their purification from saponite-containing substances.

The technical result provided by the invention is to reduce the content of saponite-containing substances in the circulating water to the level of water quality of the circulating water supply of the processing plant (less than 30 g / dm ³ ) with a degree of purification of circulating waters of more than 88%. The invention can be used to de-clog technical (reverse water, tailings dumps, etc.) waters that are characterized by a high (up to 257 g / dm ³ ) content of finely divided suspended solids formed by the destruction of minerals of the montmorillonite group (for example, saponite).

This goal is achieved by the fact that in the method for extracting saponite-containing substances from circulating water, circulating water having saponite-containing substances is subjected to electric current in a tank in the form of a bath of electrically conductive material that performs the function of a cathode into which the rotary is half immersed (rotation speed from 10 to 20 min ^-1) drum, performing the function of an anode at a voltage on the electrodes 30 to 36 and wherein the extraction is carried out with substances saponitsoderzhaschih surface of the anode drum continuously Scraper com, and the initial circulating water containing saponitsoderzhaschie suspended solids, is fed into the bath in the drum rotation direction.

Three-layer talc packs of the saponite group have uncompensated isomorphic substitutions in the octahedral and tetrahedral layers. Therefore, the packs are characterized by an excess negative charge, which is compensated by the entry of additional cations between the packs.

The method is based on the presence of a negative charge in saponites, which suggests the possibility of their sticking to a positively charged electrode - anode.

The invention is illustrated by drawings, where Fig. 1 shows a separator for extracting saponite-containing substances from recycled water, Fig. 2 shows data on rational extraction of saponite, depending on the magnitude of the voltage between the cathode and anode and on the frequency of rotation of the drum, Fig. 3 - data about the content of the solid phase (saponite) in the clarified discharge, depending on the performance of the apparatus, figure 4 - data on the extraction of the solid phase (saponite) in the condensed product depending on the performance of the apparatus, figure 5 - data extracting water (liquid phase) into the clarified discharge depending on the capacity of the apparatus, FIG. 6 shows the degree of purification of the clarified drain depending on the capacity of the apparatus, FIG. 7 shows data on the content of the solid phase (saponite) in the condensed product depending on the productivity apparatus, the table shows the technical characteristics of the experimental apparatus.

The separator consists of a drum 1, the surface of which is made of electrically conductive material (steel, aluminum, etc.). The drum 1 is driven from the engine through a gearbox and a belt drive 2. The surface of the drum 1 is connected to the positive pole of a DC voltage source through a current collector 3 and a bus. Bath 4 is located under the drum 1. Saponite-containing substances pass through the supply cavity 5 and are cleaned with a scraper 6

The method is as follows:

Recycled water having saponite-containing substances is subjected to electric current in a tank made in the form of a bath of electrically conductive material that performs the function of a cathode, into which a rotating drum that performs the function of the anode is immersed halfway, voltage is applied to the electrodes from 30 to 36 V, and the rotation frequency the drum is set from 10 to 20 min ^-1, wherein the extraction is carried out with substances saponitsoderzhaschih surface of the drum continuously with a scraper, and the initial circulating water is fed into the bath in the direction of rotation drum.

The device operates as follows:

Recycled water from the tailings dump, which has saponite-containing substances in an amount of up to 257 g / l with a particle size of less than 5 microns, is fed in a flow mode to a bath 4 located under drum 1. Bath 4 is connected via a bus to the negative pole of a constant voltage source. Saponite-containing substances passing through the feeding cavity 5 formed by the drum 1 and the bath 4 are secured to the drum 1 by electrostatic (electrophoretic) forces. During the rotation of the drum 1, a layer of saponite-containing substances is formed on its surface, which is scraped off by a scraper 6. Tails (clarified drain ) are diverted to the tailing dump or to the technological process. The separation product on the discharge chute is removed for later use. To increase the contact time of the circulating water with the drum 1, circulating water having saponite-containing substances is fed into the bath 4 in the direction of rotation of the drum 1.

The optimal extraction of saponite-containing substances is achieved when the voltage on the electrodes is from 30 to 36 V and the rotational speed of the drum is from 10 to 20 min ^-1 .

Description of the experiments.

The initial content of sludge is ~ 200 g / dm ³ , the rotational speed of the anode drum is 10 min ^-1 , the voltage between the drum and the separator bath is 30-36 V. This voltage value is selected based on the results of studying the electrophoretic velocity of saponite particles to the anode depending on voltage and preliminary studies to study the effect of stress on the extraction of a saponite-containing product (figure 2) with a separator capacity of 8 dm ³ / h (the duration of the treatment of the source water is 1.5 minutes).

In subsequent experiments, the rational productivity of the apparatus was established - 4 dm ³ / h (processing time 3 min), providing the required (less than 30 g / dm ³ ) quality of the clarified discharge by the solids content - 25 g / dm ³ (figure 3), when extracting saponite into a condensed product 93% (figure 4), extracting water into a clarified drain 57% (figure 5) and the degree of purification of 87.5% (figure 6). The content of the solid phase in the condensed (saponite) product was about 393 g / DM ³ (Fig.7). An increase in the productivity of the apparatus for draining to 6 dm ³ / h (processing time 2.3 min) and 8 dm ³ / h, regulated by the amount of water supplied, with a voltage between the drum and the bath of 30 V, leads to an increase in the solids content in the clarified drain to 49 g / dm ³ and 72 g / dm ³ (Fig. 3), which is higher than the required content, as well as to a decrease in the extraction of saponite in the condensed product from 93 to 86 and 59% (Fig. 4) and, as a consequence, the degree water purification from 87.5 to 75.5 and 41% (Fig.6), respectively.

Thus, under the conditions of the experiments, the following was established:

- the yield of clarified discharge from the source of recycled water, characterized by a solids content of 200 g / dm ³ , is from 57 to 72%, with a degree of purification of sludge-containing water from 41 to 99% and a solids content in the drain from 2 to 118 g / dm ³ ;

- the extraction of saponite in the condensed product is from 76 to 99.4%. In this case, the condensed product is characterized by a solids content of from 392.7 to 429 g / dm ³ .

Table Technical characteristics of the experimental apparatus No. Parameter Name Units measuring Value one Power Supply Performance dm ³ / h 1,0-8 2 Maximum solids content in feed water g / dm ³ 257 3 Light bleed performance up to dm ³ / h 6 four Water treatment duration Min 1,5-6 5 Condensed Productivity dm ³ / h 0.5-4 6 Solid sludge performance up to kg / h 1.4 7 Specific energy consumption for processing 1 m ^{3 of} water kWh / m ³ 8-36 8 Average line current consumption (DC) BUT 2 9 Magnitude of operating voltage AT 30-36 10 The distance between the drum - cathode and the drum - anode mm eleven eleven Drum speed min ^-1 10-20 Unit bath volume dm ³ 120

Claims (2)

1. The method of extraction of saponite-containing substances from circulating water, which consists in processing the source of circulating water in the region of the positive electrode with separation of the latter into a condensed product and clarified liquid, characterized in that the circulating water, including saponite-containing substances, is subjected to electric current in a tank made in in the form of a bath of electrically conductive material, performing the function of a cathode, into which a rotating drum, performing the function of the anode, is half immersed, voltage is applied to Electrode 30 to 36, and the drum rotation frequency is set from 10 to 20 min ^-1, wherein the extraction is carried out with substances saponitsoderzhaschih drum surface scraper continuously and recycled water is fed into the bath in the drum rotation direction. 2. A device for extracting saponite-containing substances from recycled water, characterized in that a drum is inserted into it, the surface of which is made of electrically conductive material, the drum is rotatable from the engine through a gearbox and a belt drive, while the surface of the drum is connected through a current collector and tires to the positive pole of the constant voltage source, and the bath is located under the drum and is connected via the bus to the negative pole of the constant voltage source, the device is an additional but equipped with a feed cavity and a scraper.

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