RU2742793C1 - Cascade water bubble concentrator of heavy metals - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: invention can be most effectively used for re-enrichment of tailings (waste) of gold-recovery factories for the processing of precious metal ores (gold, platinum, tin, etc.), as well as sands of placer deposits of precious metals that are in the original rock mass in dispersed state, including those brought into such a state by special techniques, for example, sieving, crushing, or their combinations. The cascade water-bubble concentrator of heavy metals contains an inlet pipe, including a receiving funnel with a float regulator, an impeller and a shaft with an electric motor and auger, a cascade system including parallel column pipes with active turbines and augers in their lower part, located in parallel and connected consecutively by means of corner bends, and the outlet pipe of the cascade system with a control valve. The column-pipes include air injectors and liquid discharge valves made with the ability to adjust the flow rate and directional movement of the precipitated particles of heavy metals.

EFFECT: increase in the coefficient of extraction of heavy components from the concentrated rock mass, as well as an increase in the quality of the concentrate and the productivity of the device.

1 cl, 3 dwg

Description

The invention relates to the mining industry and can be most effectively used for re-enrichment of tailings (waste) of gold recovery factories for the processing of precious metal ores (gold, platinum, tin, etc.), as well as sands of placer deposits of precious metals, which are in the original rock mass in a free state, including those introduced into such a state by special techniques, for example, sieving, crushing, or their combinations.

There are a fairly large number of technical solutions aimed at improving the quality of extraction of precious metals from the original rock mass, both directly in the production process of enrichment and in the process of recycling waste in order to recover the previously lost useful product.

Known technical solutions and devices (separators) of the centrifugal-vibration and vibration-gravitational type, in which the separation of the material (the enriched rock mass) by density, previously classified on a screen with set cell parameters, is carried out in a liquid medium due to centrifugal forces acting on the suspension , fed into a rotating cylindrical or truncated-conical container with ribbing of various shapes (AC No. 1651955, IPC В03В 5/32, publ. 1991; patent RU No. 21000086, IPC В03В 5/32, published 1993; patent RU No. 2100087, IPC В03В 5/32, publ. 1995, as well as the Falcon hub by SEPRO MINERAL SYSTEMS https://seprosystems.com/language/ru/products/%D0%B3%D1%80%D0%B0%D0%B2%D0 % B8% D1% 82% D0% B0% D1% 86% D0% B8% D0% BE% D0% BD% D0% BD% D1% 8B% D0% B5-% D0% BA% D0% BE% D0% BD% D1% 86% D0% B5% D0% BD% D1% 82% D1% 80% D0% B0% D1% 82% D0% BE% D1% 80% D1% 8B-falcon-sb /).

The disadvantage of these devices is the frequency of work with stops for unloading the concentrate with reconfiguring the operating mode of the apparatus, the inability to control the direction of movement of the feedstock when the vector of the resulting longitudinal component of the centrifugal force changes, which lowers the efficiency of the beneficiation process and lowers its quality.

Also known device [Patent RU No. 2432996, IPC B03B 5/70, publ. 11/10/2011], made in the form of a pipe, inclined to the horizontal and connected with the upper end to the pulp source, and the lower end to the means for draining the tailings to the dump. The longitudinal section of the pipe is a sine wave. A straight section is located at the highest point of the upper half-waves of the pipe. The lower half-waves, which are cells for collecting the concentrate, are equipped with a loosening mechanism and a means for releasing the concentrate, for example, in the form of a mechanical or electromechanical valve.

The disadvantage of the device is its complexity, the need to use loosening mechanisms and valves on each of the half waves.

Known device for the method of concentration of heavy minerals and a concentrator for its implementation [Patent RU No. 2423183, IPC B03B 5/32, publ. 10.07.2011], which is realized by creating an axially ascending spiral flow of the incoming processed pulp inside the concentrator housing, continuous discharge of light minerals and concentration of heavy minerals in the separated zones. The method is carried out using a concentrator, including a housing with concentration grooves spaced along the height of the lateral inner surface and a conical bottom located in the lower part, a tangential pipe for feeding the initial slurry inside, a device for unloading light grains of minerals - tails and a pipe for unloading heavy grains of minerals - concentrate , made in the central part of the conical bottom. The concentrator is equipped with a vertical central tube with a closed upper part, to which a tangential feed pipe of the initial slurry is connected, and a cone-shaped feed distributor located under its open lower end, installed with the possibility of axial movement and pressed tightly against the conical bottom of the concentrator in the working position. The lateral inner surface of the concentrator is made in the form of a bowl expanding upward. The radius along the angular coordinate of the bowl is made variable, changing relative to its average radius along the transverse section of the bowl, according to a periodic sign-changing law.

Disadvantage: difficulty in manufacturing, in providing passport operating modes, insufficient capturing ability due to high turbulence of fluid flows.

The closest in technical essence to the claimed are column pneumomechanical flotation machines NPO RIVS http://www.rivs.ru/oborudovanie/flotacionnoe-oborudovanie/pnevmomekhanicheskie-flotomashiny/. The column flotation machine consists of a high cylindrical vat, in the upper part of which the pulp is fed, and in the lower part there is a device through which small air bubbles are emitted into the surrounding aqueous medium. The solid components in the pulp go down, and air bubbles rise towards them. When these elements collide, conditions are created, as a result of which some particles of solid components of the pulp (hydrophobic - non-ferrous metals) are picked up by bubbles and carried to the surface of the vat, while other particles (hydrophilic-waste rocks) continue to descend and settle in the bottom of the vat ...

The disadvantage of this device is the need to supply foam-forming substances (flotation reagents), which are not environmentally safe, into the pulp, followed by purification and neutralization of the working fluid, tailings and concentrate, as well as the difficulty of removing "floating" particles from the surface of the vat with simultaneous counter supply of the pulp.

The objective of the invention is to increase the productivity of the device, improve the quality of the concentrate, ensure the possibility of operational control of the beneficiation process and improve environmental safety.

The technical result of the device proposed for this application - a cascade water-bubble pipe-column concentrator, is a decrease in operating costs and an increase in the recovery factor of heavy components from the concentrating rock mass due to repeated repetition of the pulp enrichment process in a system of cascade-placed column pipes with a closed system of use working fluid (water). In this case, the specified cascade system is equipped with simple devices for adjusting the enrichment modes in order to ensure the maximum possible extraction of useful components in a narrow fractional range.

The recovery factor is the ratio of the recovered amount of heavy components to the total amount of heavy components in the original rock mass to be concentrated.

The technical result is achieved due to the fact that the cascade water-bubble concentrator (abbreviated as KVPK) is made in the form of a set of several vertical and sequentially communicating with each other pipe columns, along which the slurry with a useful component is constantly moving in one direction from top to bottom, and from below air bubbles rise upward, in an amount sufficient to create a “cushion” through which light particles in the pulp (waste rocks) cannot pass, but particles of heavier components (noble metals) “fall through”. Each of the pipe-columns ends in a dead-end storage cup, inside which there is a screw driven by an active turbine (and on the first of the cascade pipes - by an electric motor), located on the same axis with the screw, and in turn rotating from the oncoming pulp flow; at the same time, an annular injector-emitter of air bubbles rising towards the pulp flow is placed in the storage cup.

FIG. 1 shows a cascade water bubble concentrator.

FIG. 2 shows a diagram of the movement of particles and working fluid in the zone of junction of the pipe-column with the elbow-branch (zone "A").

FIG. 3 shows a graph of the change in the rate of rise of air bubbles depending on their diameter.

KVPK consists of an inlet (central) pipe-column 8 and pipes-columns parallel to it (not indicated in the figure), forming a kind of cascade system with sequential transfer of the enriched rock mass as its fractional and material composition changes. The dimensions of the pipes-columns (height and diameter) are determined by the specified capacity and can have practical values within the range: diameter up to 2-4 meters, height up to 6m.

The inlet pipe-column 8 (head) has a receiving funnel 3, where a finely dispersed bulk mass containing a useful component is fed from the hopper 1 through the dispenser 2, with the simultaneous supply of water to the receiving funnel. The water level in the receiving funnel 3 is regulated by a float regulator 5. For a better (equally saturated) pulp preparation, an impeller 7 is placed in the receiving funnel 3, driven by an electric motor 6 with a shaft 4 located along the pipe axis, at the other end of which a screw 10 is fixed. An annular injector 9 is located under the screw 10, through which air bubbles are emitted into the surrounding aqueous medium, which are forced by a compressor (not shown in the figure).

To the inlet pipe-column 8, above the level of the screw 10, a second pipe-column, similar to the first one, and also having a shaft 13 with a screw 10 fixed at the lower end, rotated by an active turbine 14 fixed at the upper end of the shaft 13, is connected by means of an angular outlet 12, and rotated by the oncoming flow of the slurry. This is followed by the third pipe-column, structurally repeating the second pipe. Depending on the physical and mechanical characteristics of the feedstock, the type of mineral, the granulometric characteristics of the feedstock, one or more of the same pipes can be added, forming a series-connected cascade-enrichment system. The number of pipes in the cascade is determined based on the fractional analysis of the feedstock for the presence of heavy elements with an average content that economically justifies the costs of their extraction. The last outlet pipe is equipped with a liquid discharge valve 15 (valve), which regulates the amount of consumed slurry (throughput of the system), flow rate and directional movement of precipitated particles of heavy metals.

The described device works as follows.

In the inlet pipe-column 8, the movement of the slurry is set, containing solid components of a certain fraction, incl. particles of said heavy metals. To do this, the funnel 3 is fed simultaneously (in preset proportions) water (through the control valve) and dry rock mass from the hopper 1 through the dispenser 2. The portioning of these components - water and dry mass - is carried out by the metering valve 2 and the outlet valve 15, and the level ( hence the flow rate) of water is maintained by means of a float regulator 5. The resulting mixture (slurry) enters the zone of the impeller 7, where the slurry is mixed with final disintegration. The rotation of the blades of the impeller 7 is carried out by the electric motor 6.

Next, the slurry enters the inlet pipe-column 8, to which, at some distance from the impeller 7, the bend-elbow 12 from the pipe of the same or smaller diameter adjoins, the axis of which in the zone of abutment to the vertical inlet pipe-column 8 is inclined to the horizon at an angle b = 20h25 ^o . On the continuation of the vertical pipe-column 8, below the bend-elbow 12, there is a screw 10 mounted on the same shaft 4, which drives the impeller 7 into rotation. Below the screw 10, an injector 9 (diffuser) of air bubbles is placed. It is made in the form of a flat hollow ring, one side of which is closed with a mesh with a mesh of less than 0.5 mm. When air is supplied through the diffuser, a lot of bubbles are formed, the diameter of which does not exceed 1-2 mm, rising up the inlet pipe-column 8. In the interface of the bend-elbow 12 with the column-pipe, conditions are created under which the flow of working fluid (water) is redirected ( changes the direction of movement) at an angle of 65h70 ^about . Into the same zone from the bottom along the inlet pipe-column 8 from the side of the diffuser, air bubbles rise in an amount necessary and sufficient to create a kind of "cushion" that prevents the lighter particles from falling in the pulp (waste rocks), but does not hold particles of heavier components (precious metals).

The devices for adjusting the operating modes (processes) in the claimed design are: active turbines 14 with a variable angle of installation of the rotor blades, operating due to the flow of working fluid (water); taps of injectors 9, which regulate the amount of air supplied in the form of bubbles to the pulp flow; valves 16 for dumping part of the working fluid in the corresponding pipe-column; outlet valve 15 and dispenser 2 of the bulk mass together with the water supply valve (not indicated in the figure) to the funnel 3. The choice of the operating mode of the system elements is made according to the indicator of the highest yield of useful components in the removed concentrate by setting up a series of experiments with the same initial portion rock mass to be concentrated.

As you know, the rate of rise of bubbles in pure water is determined by the size of the bubble and is expressed by a dependence of the form V = 100√d, mm / s or the graph in Fig. 3 (valid for bubble diameters up to 4х5mm). It follows from this that the speed of the slurry in the column-pipe should be significantly lower than the rate of rise of air bubbles, which should be taken into account when setting the productivity of the installation.

At the same time, the rate of subsidence of solid particles in water (speed of hovering) of waste rock and useful component differ by 3.5–4 times. Consequently, all other things being equal, when particles leave the boundary of the zone "A", their behavior will obey the laws of inertia, and thus the probability of a heavier particle to overcome this zone will be higher. Lighter particles of pulp components, the fall of which is restrained by rising air bubbles, are much more likely to be picked up by the flow of working fluid curving in zone "A" and carried into the adjacent pipe-column.

Since solid particles (both waste rock and useful component) have different physical properties, sizes and shapes, it is difficult to ensure 100% separation of particles in the above zone "A", and both the penetration of waste rock particles downward and and removal of precious metal particles into the adjacent pipe-column. Therefore, to reduce the dilution of the concentrate settling in the lower (dead-end) part of the inlet pipe-column 8, a device is provided in the form of a screw 10, located in its lower part (in a glass).

When the electric motor 6 is turned on, the impeller 7 and the auger 10 start to rotate. The spiral of the auger 10 and its rotation create a cycle in the dead-end part of the inlet pipe-column 8: an upward flow of pulp in the central part of the inlet pipe-column 8 and descending on its peripheral part. The speed of rotation of the screw 10 and the steepness of its spiral are selected in such a way that they create conditions for picking up lighter particles of solid (waste rocks) in the pulp and, together with the rising bubbles, contributes to their removal into the elbow 12 of the adjacent pipe (zone "A") ... In this zone, they enter the deviating pulp flow at the transition to the second pipe-column. (see Fig. 2). In this case, the heavier particles of useful components of the pulp are not picked up by air bubbles and the blades of the screw 10, but are lowered into the receiving chamber 11.

Ensuring the necessary conditions for the deposition of heavy components of the slurry in the vertical inlet pipe-column 8 is achieved by adjusting the flow rate of the slurry in it using the control valve 15, adjusting the density of the pulp (S: L ratio) using the valve 2 and adjusting the air flow rate (the number of bubbles and their size).

In the adjacent pipe-column, the same processes and dependencies will take place as in the inlet pipe-column 8. The difference is that the screw 10 rotates from the active turbine 14, which in turn is driven by the oncoming pulp flow. In addition, in accordance with the principle of operation of the inventive device, the second pipe-column is most likely to receive from the first pipe-column smaller particles of the useful component or flatter ones, which for one reason or another have avoided favorable conditions for settling in the first pipe-column. In this regard, the mode of operation of the second pipe-column may differ from the mode of operation of the first (inlet) pipe-column, mainly in terms of setting the flow rate of the working fluid. More precisely, to reduce this speed due to a decrease in the particle size of the useful component. For this, the design of the military-industrial complex provides for the possibility of dumping part of the working fluid using the valve 16.

Claims (1)

A cascade water-bubble concentrator of heavy metals, containing an inlet pipe, including a receiving funnel with a float regulator, an impeller and a shaft with an electric motor and auger, a cascade system, including parallel pipes with active turbines and augers located in parallel and connected in series by means of corner bends in their lower part, the outlet pipe of the cascade system with a control valve, and the column pipes include air injectors and liquid discharge valves, are made with the possibility of adjusting the flow rate and directional movement of the precipitated particles of heavy metals.

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