RU2351397C2 - Method of cleaning mineral grains from flotation reagents and sludge coating and device for implemetation of this method at ore concentrating - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention refers to cleaning of mineral grains contained in pulp products at ore concentrating from undesirable sediments such as flotation reagents and sludge coating and can be implemented for mechanical activation of non-ferrous and ferrous metal ores, for coal and other minerals prior to operation of desorption and also prior to operations of selective separation of concentrates, and to cleaner flotation for production of finished concentrates. The method of cleaning mineral grains in ore suspension such as flotation reagents and sludge coating consists in tangential supply of source suspension under pressure into a working zone of the cylinder part of the case via a flow divider arranged so that counter flows collide in the zone of flow compression and deformation; this zone is limited with the interior wall of the cylinder part of the case and with curvilinear exterior part of the splitter installed on a discharge sleeve. The method is implemented by means of the device including a cylinder case with two tangential feeding sleeves arranged at various height, set off along perimeter of the cylinder approximately at 180° and communicating between them by means of the divider supplying source suspension into them; also the device includes a conic part of the case with a sand nozzle located under the cylinder part of the case. The discharge sleeve with the splitter secured thereon is made in form of exterior and interior cylinder surfaces. The interior surface of the splitter has radius r₁ calculated from radius R of the cylinder part of the case. The exterior surface of the splitter limiting the zone of flow compression and deformation is made in form of ellipse with half-axes r₁ and r₂, where radius r₂ is bigger, than r₁.

EFFECT: increased efficiency of mineral grains cleaning from flotation reagents and sludge coating, also reduction of power consumption.

6 cl, 4 dwg

Description

This invention relates to a method and apparatus for cleaning mineral grains contained in pulp products during ore processing from flotation reagents and sludge coatings.

In the process of ore preparation, both primary and secondary sludges are found in the pulp before beneficiation, which equally negatively affect subsequent technological processes.

It is also known that in the process of flotation enrichment and in general when mineral grains are in contact with water, oxide films and chemical compounds form on the surface of the mineral grains that impede interaction with flotation reagents, which ultimately negatively affects the technological efficiency of flotation.

Several methods are known for “scrubbing” oxide films (purification of mineral grains from flotation reagents and sludge coatings) or “old” chemical compounds of flotation reagents from the surface of mineral grains. These methods can be divided into the following two groups:

- "rough grinding" in mills or

- "thin scrubbing" in special devices.

The first method of cleaning the surface of mineral grains from flotation reagents and sludge coatings - “rough grinding” in mills — occurs in dense suspension with an increased solids content in the pulp, which has a positive effect on subsequent technological processes, but is accompanied by overgrinding of ore grains, which negatively affects on the extraction of the useful component in the concentrate and on the increased loss of metals with tailings in subsequent enrichment or processing operations. In practice, it is not always possible to create the required high pulp density for “scrubbing”, in addition, the process of this operation requires significant energy consumption.

The disadvantage of this method is the narrow scope of dense pulps with a high solids content and over-grinding of ore grains.

In the second method of cleaning mineral grains from flotation reagents and sludge coatings - “thin scrubbing” in special apparatuses — cleaning takes place in scrubbers due to centrifugal forces by mixing diluted pulp. Since precipitation effects counteract the implementation of this method, neither large volume flows nor highly concentrated pulps can be used. So this method is ineffective and requires a significant processing time and, as a result, large production areas. The creation of turbulent flows in the entire volume of highly diluted pulp does not provide a sufficient probability of collision of ore grains with each other due to the low solids content in the pulp. Additionally, rubbing occurs due to the friction of the grains on the fixed wall of the tub body. However, this effect in practice does not provide significant advantages.

In practice, in ore dressing, the proportion of solids in the feed material after preparatory processes is 20-30%. With this fraction of solids, the probability of collisions between ore grains is very small. Filling tanks with agitators are ineffective and also require a lot of time.

There are a number of methods for separate conditioning of pulp parts and for cleaning the mineral surface for their subsequent separate and joint processing. The following types of separate conditioning and cleaning of the mineral surface are distinguished:

- cleaning only the granular fraction and its further processing (thin sludge is not processed);

- separate cleaning of granular and sludge fractions before their separate processing;

- separate cleaning of granular and sludge fractions before their joint processing.

For all three methods of conditioning and cleaning the mineral surface, an apparatus is needed for separation into granular and sludge fractions. For the first method, an apparatus for processing the granular fraction is additionally needed, and for the second and third types of processing, additional apparatuses for cleaning the granular and sludge fractions are needed.

A significant disadvantage of the known methods for cleaning the mineral surface are the bulkiness of the hardware design.

In the ore beneficiation industry, for the classification of ore, a non-impeller hydrocyclone type device has been used for a long time, containing a housing having cylindrical and conical parts, a tangential inlet pipe, and drain and sand pipes located symmetrically relative to the axis of the cylinder.

From patent DE 4224948 A1, a technology for processing a fine-grained charge is known, in which the water column in the fluidized bed tank is completely or partially subjected to vibration.

From DE 3838500 A1 a method and a device for hydromechanical treatment of water dispersible mineral substances with a turbodispersive device are known, in which ordinary hydrocyclones can be used.

The basis of this invention is the task to develop a method for particularly effective cleaning of mineral grains from flotation reagents and slurry coatings and to develop an energy-saving, compact and maintenance-free device.

The solution to the above problem occurs using the method with the features according to paragraph 1 of the claims and using the device according to paragraph 3 of the claims.

Preferred embodiments of the invention follow from the dependent claims.

In relation to the method, the problem is solved in that with the method of cleaning the feed material in the aqueous suspension, in particular for cleaning mineral grains in the ore suspension from unwanted deposits, such as flotation reagents and sludge coatings, including the tangential feed of the initial suspension under pressure into the working the area of the cylindrical part of the body, the unloading of heavy grains through the sand nozzle in the conical part of the body and light grains through the drain pipe, according to the invention, the feed suspensions are carried out by at least two streams displaced along the height and around the perimeter of the cylindrical part of the housing, through a flow divider with the possibility of colliding counter flows in the compression and deformation zone, limited by the inner wall of the cylindrical part of the housing and the curved outer surface of the divider mounted on the drain branch pipe.

When the initial power is supplied tangentially under pressure to the working area, the flotation reagent foam is removed through a drain pipe.

In relation to the device, the problem is solved in that in the device for cleaning mineral grains in suspension from flotation reagents and sludge coatings, in ore dressing, including a cylindrical body with a tangential feed pipe and a drain pipe located under the cylindrical conical part of the body with sand nozzle, according to the invention, the cylindrical part of the housing is equipped with an additional tangential feed pipe and a divider, mounted on the drain pipe and made in the form of the outer and inner cylindrical surfaces, and the inner surface of the divider has a radius r ₁ calculated based on the radius R of the cylindrical section of the housing, and the outer surface of the divider, limiting the compression and deformation of the flows, is made in the form of an ellipse with half shafts r ₁ and r ₂ , and the radius r _{2 is} greater than r ₁ , while the tangential supply nozzles are located at different heights, are displaced along the perimeter of the cylinder by about 180 ° and communicated with each other by means of a divider that feeds the initial suspension into them Yu.

The radius r _{1 of the} inner surface of the divider is calculated based on the radius R of the cylindrical section of the housing according to the formula r ₁ = (0.75-0.85) R, and the radius r _{2 of the} outer surface of the divider is preferably (0.8-0.9) R.

A vertical groove is made on the outer surface of the divider.

The divider is mounted on the drain pipe in a certain angular range with the possibility of free rotation about an axis, which approximately coincides with the middle axis of the cylindrical body.

An essential aspect of the method according to the invention is the preparation of grains for subsequent processes. In this case, the source material is divided into two (if necessary, more) streams, and the mineral surface is cleaned due to the impact collision of the grains of two streams according to the “stream to stream” principle.

The meeting of these two streams takes place preferably in the compression and deformation zone of the streams, separated from the rest of the working field by a divider. The presence of a divider ensures the fulfillment of several functions: the distribution of the flow moving from the inlet along the tangent along grain sizes with the subsequent separation and direction of wall flows into the compression and deformation zone with simultaneous compression and increase in the concentration of solid. The thickness of the wall layer depends on the concentration of grains in the feed and on centrifugal acceleration.

The presence of the divider surface described by the ellipse, intensifies the directional deformation of the flows due to the narrowing of the working space between the wall of the apparatus and the outer wall of the divider. As a result, the effect of various factors and types of friction is enhanced, the influence of which determines the nature and effectiveness of cleaning the mineral surface. Among these factors are the mechanical interaction of the grains with each other and with the walls of the cylinder and the divider, the presence in the flows of local irregularities and turbulent vortices caused by the flows encountered with each other, and also the unevenness of the concentration fields.

In addition, the shape of the outer wall of the divider, made in the form of a curvilinear profile of variable cross section, contributes to a sharp disturbance of the flow of grains moving along the cylindrical wall of the body towards each other, which creates the conditions for mixing already concentrated grains in the wall layer. The shape of the compression zone is a source of additional turbulization, which allows to increase the intensity of mixing in the working area and significantly increases the efficiency of cleaning mineral grains from flotation reagents and slurry coatings.

Preferred effects of the present invention are achieved, in particular, by compression of the flow lines; increase in pressure due to narrowing of the working space; reversing the direction of flows in the compression zone and deformation of the stream; the specific shape of the divider, as well as the preferably provided vertical groove in the divider, which makes possible turbulence and unloading of flows under the action of the resulting force in the direction of gravity.

Below the invention is explained in more detail on the example of execution involving drawings, which show:

Figure 1 is a top view of the device according to the invention;

Figure 2 is a side view of the device according to the invention;

Figure 3 is an enlarged image of the compression zone and deformation of the stream;

Figure 4 - image of the resulting streamlines.

Accordingly, FIGS. 1 and 2, a device for cleaning mineral grains from flotation reagents and slurry coatings consists of the following elements: a cylindrical body 1 with two inlet nozzles 2 and 3 tangentially connected 4 and 5 with a cylindrical body 1, as well as a divider 6, mounted on drain pipe 9 with the possibility of rotation about the axis of the device.

According to figure 3, the divider 6 is directed by the cylindrical inner surface 12 to the drain pipe 9. The outer surface 13, formed by an ellipse curve, faces the cylindrical body 1 of the device. Zone 14 compression and deformation of the flow occupies the space between the inner wall of the cylindrical body 1 and the outer surface 13 of the divider 6.

According to figure 4, the zone 14 of compression and deformation of the flow is limited by the outer surface 13 of the divider 6, the inner surface 12 of which is a circle with a radius r ₁ , preferably in the range

r ₁ = (0.75-0.85) R,

where R is the radius of the cylindrical body 1.

The outer surface 13 of the divider 6 is described by the generatrix of the surface of the ellipse with half shafts r ₁ and r ₂ ,

Where:

r ₂ = (0.8-0.9) R,

moreover

r ₁ <r ₂ .

A device for cleaning mineral grains from flotation reagents and sludge coatings works as follows.

The initial suspension with a certain solid content under pressure from the pressure pipe enters the flow divider 11, from which through two nozzles 2, 3 located tangentially to places 4, 5 of their entry into the cylindrical body 1, it enters the discharge chamber of the cylindrical body 1. Under the action centrifugal force of grain of different sizes move along different trajectories to the walls of the cylindrical body 1.

The largest and heaviest grains are released onto the wall immediately after the initial pulp enters the centrifugal apparatus and ultimately precipitates through the sand nozzle 16. When moving downward, the condensed fraction from the nozzle 2 meets the flow from the nozzle 3 in the compression and deformation zone 14 limited curved outer wall 13 of the divider 6. Two slurry flows directed to each other meet in the compression and deformation zone 14, one part of the grains penetrates the oncoming flow, where increased mechanical friction occurs ezhdu grains. Another part of the grains is subjected to reversal and swirl. As a result, both flows are jointly unloaded into the expanding part of the compression and deformation zone 14, which is formed by a longitudinally elongated groove 7.

The divider 6, on the one hand, provides the separation of the stream with a low content of solid and sludge grains from the stream with a high content of solid and granular components of the stream and, on the other hand, forms a zone 14 of compression and deformation of the stream.

Since the divider 6 with the mount 8 of the divider is located at least in a certain angular range with the possibility of free rotation relative to the middle axis of the cylindrical body 1, the action of each of the flows is balanced by the divider 6 depending on the amount of flowing substance and the pulp pressure in each of the supply pipes 2 and 3, and the divider 6 is automatically oriented in the compression and deformation zone 14 of the flow. Thus, the divider 6 is installed and balanced by the flow of the suspension due to free rotation around the axis of the housing so that the pressure differences are equalized each time. Since the divider 6 according to this invention is preferably rotatably mounted on the drain pipe 9, the divider 6 is always in a balanced state and, therefore, in the center of interaction of forces.

In the claimed device for cleaning mineral grains from flotation reagents and sludge coatings, in addition to the two main external streams of the feed source, which are found in the zone 14 of compression and deformation of the streams, an internal stream is also formed, which spirals upward to the drain pipe 9. Upward axial flow, into which thin sludge grains and scouring products fall as remnants of flotation reagent films, sludge coatings, etc., are discharged through outlet 15 of drain pipe 9. The cleaned granular part of the pulp is discharged from the device through the sand nozzle 16 of the conical part 10 of the housing.

In the above-described devices, the concentrated material of the granular part of the pulp is mainly processed due to the centrifugal forces arising from the tangential introduction of the pulp from two sides. The collision of two streams with a higher solid content also has an activating effect on the treated suspension.

The device according to the invention can be used for the mechanical activation of ores of non-ferrous and ferrous metals, coal and other minerals whose mineral grains have been in contact with the liquid phase and flotation reagents for a long time.

In addition, such devices can be used before desorption operations, before operations of selective separation of concentrates, before purification operations to obtain the finished concentrate.

According to this invention, a device for cleaning mineral grains from flotation reagents and sludge coatings can be successfully used for pulp beneficiation products whose flotation activity is reduced during flotation enrichment due to prolonged exposure of ore grains in contact with an aqueous medium.

Another area of application of this device is the scrubbing of oxide films from quartz sand used in the glass industry.

Reference designations

1 - cylindrical body

2, 3 - supply pipes

4, 5 - inlets of the supply nozzles

6 - divider

7 - groove in the divider

8 - mount mount divider

9 - drain pipe

10 - conical part of the body

11 - flow divider

12 - the inner surface of the divider

13 - the outer surface of the divider

14 - zone of compression and deformation of the flow

15 - outlet of the drain pipe

16 - sand nozzle

Claims (6)

1. A method of cleaning a feed material in an aqueous suspension, in particular for cleaning mineral grains in an ore suspension from unwanted deposits, such as flotation reagents and slurry coatings, comprising tangentially supplying a pressure of the initial suspension to the working area of the cylindrical part of the body, unloading heavy grains through a sand nozzle in the conical part of the housing and light grains through a drain pipe, characterized in that the feed of the initial suspension is carried out by at least two streams, offset nnym height and along the perimeter of the cylindrical body portion, through the flow divider, with pushing counter flows in the compression and deformation zone flows delimited by an inner wall of the cylindrical body portion and a curved outer surface of the deflector mounted on the spout. 2. The method according to claim 1, characterized in that when the initial power is supplied tangentially under pressure to the working area, the flotation reagent foam is removed through a drain pipe. 3. A device for cleaning mineral grains in suspension from flotation reagents and slurry coatings during ore processing, including a cylindrical body with a tangential feed pipe and a drain pipe located under the cylindrical conical part of the body with a sand nozzle, characterized in that the cylindrical part the housing is equipped with an additional tangential feed pipe and divider, mounted on the drain pipe and made in the form of external and internal cylindrical surfaces, comb m the inner surface of the divider has a radius r ₁ calculated on the basis of the radius R of the cylindrical section of the housing, and the outer surface of the divider, limiting the zone (14) of compression and deformation of the flows, is made in the form of an ellipse with half shafts r ₁ and r ₂ , and the radius r ₂ more than r ₁ , while the tangential supply nozzles are located at different heights, are displaced along the perimeter of the cylinder by about 180 ° and communicated with each other by means of a divider that feeds the initial suspension into them. 4. The device according to claim 3, characterized in that the radius r _{1 of the} inner surface (12) of the divider (6) is calculated based on the radius R of the cylindrical section (1) of the housing, according to the formula r ₁ = (0.75-0.85 ) R, and the radius r _{2 of the} outer surface (13) of the divider (6) is preferably (0.8-0.9) R. 5. The device according to claim 3, characterized in that on the outer surface of the divider a vertical groove is made. 6. The device according to any one of claims 3 to 5, characterized in that the divider (6) is mounted on the drain pipe in a certain angular range with the possibility of free rotation about an axis that approximately coincides with the middle axis of the cylindrical body (1).

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