WO2013095179A1

WO2013095179A1 - Method for pneumatically concentrating mineral raw materials

Info

Publication number: WO2013095179A1
Application number: PCT/RU2011/001019
Authority: WO
Inventors: Андрей Иванович СТЕПАНЕНКО
Original assignee: Stepanenko Andrei Ivanovich
Priority date: 2011-12-22
Filing date: 2011-12-22
Publication date: 2013-06-27
Also published as: EA201201684A1; EA022959B1

Abstract

The invention relates to the field of concentrating mineral raw materials and can be used for the production of mobile concentration factories which are intended for the fractional processing and classifying of raw materials under virtually any suitable conditions, including at ambient air temperatures of from -50 to +50 °С. What is claimed is a method for pneumatically concentrating mineral raw materials, the method comprising placing the raw materials to be concentrated on an air-permeable surface traversing a vertical chamber with a rising air current which lifts light fractions from the air-permeable surface, said light fractions then being transferred by the air current into a gravitational deposition chamber. What is novel is the fact that the air-permeable surface is in the form of a conveyor passing through at a level lower than the lower base of one or more consecutively mounted vertical chambers, in each of which selection of the air current velocity results in the formation of a three-dimensional pseudo-fluidized bed of particles of a specified density, into and through which less dense particles enter and pass freely and are then transferred by the rising air current out of the vertical chamber into the gravitational deposition chamber.

Description

Method for pneumatic mineral processing

The invention relates to the field of mineral processing and can be used to create mobile processing plants for processing and classification of raw materials into fractions in almost any weather conditions, including at ambient temperatures from -50 to +50 ° FROM.

State of the art

It is known that over the years of operation of concentration plants and metallurgical plants, huge volumes of technogenic waste have accumulated, which not only pollute the environment and remove huge land areas located in close proximity to villages, cities and other settlements. Most of these mineral wastes are valuable raw materials for recycling. For example, ferrochrome production slags contain from 2 to 12% metallic ferrochrome, while the content of chromium in ore entering the smelting is from 1 to 5%, moreover, in a chemically bound state. Therefore, the secondary processing of slag can not only improve the ecology of the region, but is also economically feasible, while the technology for processing these wastes must satisfy a number of stringent requirements.

Firstly, the technology for the enrichment of raw materials should be universal, easily tunable for processing various types of mineral raw materials, and at the same time be suitable for the enrichment of materials with different densities (coal, ore, industrial waste and non-metallic raw materials). The processing process should provide for the ability to quickly and smoothly change technological regimes depending on the properties of the processed raw materials, the requirements for the quality of processed products, etc., which will allow the creation of mobile processing plants of a modular type, with a low level of capital costs for them delivery and installation.

Secondly, the technology for enrichment of raw materials must be highly efficient, ensuring high quality of the products obtained, and so that after its application, only those wastes that are not suitable for further processing or direct use remain. Thirdly, the technology for the enrichment of raw materials should be all-weather and year-round so that the process does not take place seasonally with temporary attraction of labor resources, but proceeds constantly - with year-round employment of the local population. For this reason, the technological cycle of enrichment of raw materials should include a range of ambient temperatures from -50 to +50 ° C and should allow the equipment to be placed outdoors or using light type shelters.

A known method of enrichment of raw materials, widely used at present, based on the separation of products by density in a liquid medium (see Razumov K. A. Perov A. A. "Design of processing plants" M., Nedra 1982, pp. 195-205 , 268-282). The method allows, in the presence of large and cheap water resources, to provide a sufficiently efficient process for the enrichment of raw materials.

The main disadvantage of the known method of enrichment of raw materials is the inability to use it in winter conditions under the open sky. The construction of specialized enrichment plants operating all year round requires significant material and financial resources to provide heating, which does not allow to obtain competitive products in a known manner when working in winter conditions even in mid-latitudes with moderately cold winters (peak values of negative temperatures are in the range from - 5 to -10 ° С).

There is also a known method of enrichment of raw materials, widely used to date, based on the separation of products by density in air (see M.V. Verkhoturov “Gravity enrichment methods” M., Max Press 2006, p. 306 -318), G.N.Shohin A.G. Lopatin “Gravity enrichment methods”, M., Nedra 1993, p. 9, including the supply of enriched raw materials to the gravitational deposition chamber, making reciprocating movements, equipped with a sieve, from below which receives a stream of air. As you move along the sieve, heavy grains tend to go down, light grains rise to the top of the layer created from the processed product.

The method allows year-round enrichment of raw materials under the open sky or using light type shelters. The main disadvantage of the known method of enrichment of raw materials is the low efficiency of the process of separation of products, a high degree of infection of heavy products with light fractions, because the process is carried out in the product layer located on the sieve. An increase in the layer thickness, necessary for the formation of separate layers from products of different densities, leads to its high resistance, and as a consequence, a low degree of loosening and low efficiency of fraction separation.

Another disadvantage of this method is the inability to ensure rapid restructuring of the process for processing various types of mineral raw materials, because each separator is created to process products with a given density range.

In addition, the known method of enrichment of raw materials does not allow for highly efficient separation of the raw materials into fractions due to the high influence of the moisture content of the raw material on the process.

Closest to the claimed technical solution (prototype) is a method of mineral processing (see the description of the application WO 96/09901, class B07B 4/08, 1996), placing the raw material on an air-permeable surface intersecting the vertical chamber with the ascending an air stream lifting light fractions from the air-permeable surface, which are then transferred by a stream of air to the gravitational deposition chamber. The known method allows year-round enrichment of raw materials in the open air or with the use of light type shelters, as well as quick adjustment of the technological process for processing various types of mineral raw materials by changing the air flow rate.

The main disadvantages of the known method are, firstly, its limited functionality. For one enrichment cycle, the method allows to divide the enriched raw material into only two density fractions, one of which settles in the gravitational deposition chamber, and the second remains on the air-permeable surface and, due to its vibration, is removed from the separation zone, and one small fraction size having a size less than the mesh size of the breathable surface and waking up through the breathable surface down. Another disadvantage of the known method is that the productivity of the process, which can be obtained using this method, is limited by the productivity of removal of the heavy fraction, which does not allow to effectively separate mineral raw materials.

In addition, the known method does not allow to organize high efficiency of separation of raw materials into fractions, due to the non-uniformity of the velocity field of the air flow in the chamber due to air suction through asymmetric side openings designed to supply raw materials and output heavy fractions.

Disclosure of invention

The basis of this invention is the task of eliminating these disadvantages, namely, the creation of a universal method that allows to enrich various types of mineral raw materials and industrial waste, such as gold and polymetallic ore, ferrous metal ore, coal, non-metallic minerals, slag, clinkers etc.

The indicated problem in the method of pneumatic enrichment of mineral raw materials, including the placement of enriched raw materials on an air-permeable surface intersecting a vertical chamber with an ascending air flow, lifting light fractions from the air-permeable surface, which are then transferred by a stream of air to the gravity deposition chamber, is solved by that the air-permeable surface is made in the form of a conveyor of one or several vertically installed vertically passed below the lower base level of chambers, in each of which a volume pseudo-boiling layer of particles of a given density is formed by choosing the velocity of the air flow, into which particles of lower density enter and freely pass through it, and then are transferred from the vertical chamber to the gravity deposition chamber via an ascending air flow.

The presence of several successively installed vertical chambers, in each of which there is a volume pseudo-boiling layer of particles of a given density, into which particles of lower density enter and pass through it without hindrance, it allows simultaneously organizing multi-threaded pneumatic separation of the enriched raw material into several fractions, which significantly simplifies not only the separation technology, but also significantly (several times) reduces the cost of the enrichment process.

The presence in each of the vertical chambers of its own adjustable mode of air intake with the establishment of its individual air flow rate (constant or variable), allows you to very quickly reconfigure the modes of enrichment of raw materials, and taking into account the possibility of installing different sizes of cells of a breathable conveyor (constant or changeable), the claimed method significantly expands its functionality.

The possibility of creating intermittent movement of the conveyor as a result of the action of alternating accelerations allows for a more uniform distribution of particles on an air-permeable surface and to eliminate blocking of particles under a layer of other particles.

Adjusting the location of the conveyor relative to the level of the lower part of the chamber allows you to quickly reconfigure the process when changing the size of the processed product.

The use of a moving conveyor belt with an air-permeable web as a conveyor makes it possible to ensure high productivity of the process.

The use of a conveyor with a variable cell size from chamber to chamber allows covering the entire possible combination of fractions of the enriched raw material in one separation cycle.

The use of a vibration conveyor makes it possible to simplify structural solutions in cases where there is no need to organize high process performance, but there are limitations on the area and dimensions of the equipment being placed.

The use of a conveyor in the form of a rotating disk is justified if it is necessary to compactly place equipment on a limited area.

The use of a rotating drum as a conveyor also makes it possible to create a compact simple installation for separation of 2-3 fractions, which operates with high productivity. Thus, the inventive method allows to separate mineral raw materials into almost any number of fractions for one cycle of processing of raw materials, which has no analogues among the known methods of pneumatic separation, which means that it meets the criterion of "inventive step".

Brief Description of the Drawings

The inventive method is illustrated by drawings in FIG. 1-4. 1 is a pneumatic diagram of a separation device explaining the essence of the proposed method, comprising: a feeder 1 with a mixture of shared raw materials 2; an air-permeable belt conveyor 3, under which a vibratory conveyor 4 is mounted (a vibrating trough driven by, for example, an electromagnet or a vibration motor) on spring guides 5; vertical suction chambers 6 (6a-6p) connected through suction ducts 7 (7a-7p) to gravity deposition chambers 8 (8a-8p), which are connected to fans 10 (10a-10p through air ducts 9 (9a-9p) ); lock gates 1 1 (1 1a-1 1p), forming fractional batches of raw materials 12 (12a-12p); fractional batches of raw materials 13 (poured from conveyor 3) and 14 (small fraction waking up through conveyor 3).

Figure 2 shows a diagram of a device for implementing the inventive method, where the conveyor is made in the form of a vibration conveyor 15 on the spring guides 16.

Fig. 3 shows a diagram of a device for implementing the inventive method, where the conveyor is made in the form of a rotating disk 17 with an air-permeable surface 18 and a raw material ejector 19 (fixedly mounted over the disk with a minimum plate gap).

Figure 4 presents a diagram of a device for implementing the inventive method, where the conveyor is made in the form of a rotating drum 20 with an awakening surface (not shown in the figure), over which vertical chambers 6 are installed along its axis, and inside the drum, a vibratory conveyor 4 on spring guides 5.

The best embodiment of the invention

The implementation of the proposed method will be considered on the installation shown in figure 1. From the feeder 1, the processed raw material 2, which is a granular granular mixture, previously divided into classes by size and consisting of grains that differ in density, are distributed uniformly on the moving surface of the web of a breathable belt conveyor 3. The smallest fraction immediately wakes up through conveyor 3 to a vibratory conveyor 4, from which it is poured into a small fractional batch 14. Larger particles they move on the conveyor 3 past the lower open sections of the suction chambers 6a-6p and, due to the suction air flows from the fans 10a-10p, enter the suction chambers 6a-6p. Any number of chambers 6a-6p can be located above one conveyor 3, providing the required number of fractions of various densities. Each of the chambers 6a-6p has its own individual air flow rate regime, which, sucking particles with a given density, creates in them a volumetric pseudo-boiling layer through which particles of lower density freely pass, which then pass through air ducts 7a-7p fall into the gravity deposition chambers 8a-8p, where the air flow slows down and the particles settle to the bottom of the chambers 8a-8p and then continuously or periodically are removed through the sluice gates 11a-11p, forming fractional batches of raw materials 12a-12p . All those particles that turned out to be the heaviest and did not enter the chambers 6a-6p are poured from the conveyor 3 into the fractional batch 13. Thus, all the feed coming into the separation is simultaneously divided into the corresponding number of fractions.

Similarly, the installation shown in figure 2. The difference is that the conveyor is made in the form of a vibratory conveyor 15.

The installation shown in FIG. 3 works in a similar way, but is performed using a disk conveyor 17 with an air-permeable surface 18. The particles 2 remaining on the disk conveyor 17 are discharged by a raw material ejector 19.

The installation shown in FIG. 4 is made using a rotating drum 20 with an awaking surface, inside which a vibratory conveyor 4 is installed.

Technical applicability

The specific implementation of the proposed method will consider the examples of enrichment of various mineral raw materials. EXAMPLE 1

Let us consider slag separation of ferrochromic production for further production of ferrochrome. The process of pneumatic enrichment will consider the installation shown in figure 1. The production line capacity is 50 t / h. Before processing, the slag is pre-crushed to a particle size of 0 - 6 mm and fed to a belt conveyor 3, with a web made of mesh with a mesh of 1 mm, a width of 600 mm and moving at a speed of 0.5-1.5 m / s, over which two rectangular chambers 6a and 66 with a cross section of 600x150 mm and a height of 900 mm. The chambers are connected to gravity deposition chambers 8a and 86 with a diameter of 1200 mm and a height of 2500 mm.

Slag particles with a size of less than 1 mm wake up under the mesh of the conveyor 3 and fall on a vibrating trough 4, removing the product from under the conveyor 3.

The air flow in the chambers is selected in such a way that in the first chamber a product is released that does not contain ferrochrome grains and has a density of less than 2.9 t / m3, grains containing up to 50% ferrochrome and have a density of 2.9 to 7.0 are released in the second chamber t / m3, this product is sent for secondary remelting, on the conveyor 3, after passing through both chambers 6a and 66, metal ferrochrome remains with insignificant inclusions of slag and is a commodity concentrate.

EXAMPLE 2

Consider the separation of high-quality coal concentrates from anthracite from the Gorlovsky deposit (see FIG. 1). The objective is to obtain a super-low ash concentrate, the demand for which has increased sharply in recent years, and to increase the total cost of marketable products obtained as a result of coal processing. The production line capacity is 500 t / h. During processing, coal is classified into machine classes, and coal with a fineness of less than 13 mm is received for processing, which in turn is divided into classes 0-6 and 6-13 mm, each of which is processed separately. Particles with a particle size of 0-6 mm are fed to a conveyor belt 3, with a web made of mesh with a mesh of 1 mm and a width of 1000 mm, moving at a speed of 1.0-2.0 m / s, above which four rectangular chambers 6a, 66, 6c and 6g with a cross section of 1000x200 mm and a height of 1200 mm. The chambers are connected to gravity deposition chambers 8a - 8g with a diameter of 1800 mm and a high that 2500 mm. Particles of coal with a size of less than 1 mm wake up under the mesh of the conveyor 3 and fall on the vibrating groove 4, which removes the product from under the conveyor. The air flow in chambers 6a - 6g is selected in such a way that a product with a minimum ash content of 2.4%, which is a valuable raw material for non-coke metallurgy, is released in the first chamber 6a, coal grains with a total ash content of no more than 9 are separated in the second chamber 66 % and used for the production of electrodes for the aluminum industry, a high-quality energy concentrate with an ash content of no more than 17% is released in the third chamber 6c, and a low-quality concentrate with an ash content of up to 26% in the fourth chamber 6g. On the conveyor 3 grid there remains a product represented by non-combustible minerals with an ash content of at least 78-80%. Anthracite with a particle size of 6-13 mm is processed on a similar installation, characterized in that the mesh size of the conveyor belt 3 is 5 mm. Vertical chambers 6a-6g are made in the size 1000x250 mm with a height of 1500 mm, deposition chambers 8a-8g with a diameter of 2000 mm and a height of 3500 mm.

EXAMPLE 3

Consider the separation of gold from polymetallic ore of complex mineral composition in the installation shown in Fig 2. The ore is represented by minerals of various densities: carbonate rocks and quartz having a density of 2.6-2.9 t / m; intergrowths of sulfide minerals with quartz having a density of 2.9-3.5 t / mZ; sulfide minerals having a density of 3.5-4.3 t / m; sulfide minerals with insignificant gold inclusions having a density of 4.3-5.0 t / m ³ ; sulfide minerals having significant gold inclusions with a density of 5.0-8.0 t / m ³ ; gold nuggets with inclusions of rocks and having a density of 8.0-18 t / m. The line capacity is 5 t / h for the initial ore. The ore is preliminarily crushed to a grain size of 0-4 mm, which provides the beginning of the opening of mineral grains. Particles with a particle size of 0-4 mm are fed to a vibrating conveyor 15, with a sheet made of steel sheet with holes of 0.5 mm and a width of 600 mm, above which there are five rectangular chambers 6a-6d with a section 600x100 mm and a height of 1000 mm. The chambers are connected to gravity deposition chambers 8a-8d with a diameter of 800 mm and a height of 1500 mm. A small product with a particle size of less than 0.5 mm wakes up through the grid to the gutter 4 and is discharged beyond the boundaries of the device (sent to the far flotation processing). In the first chamber 6a, waste rock with a density of less than 2.9 t / m is released, which is disposed of in the dump, which allows reducing the load on further processing processes and lowering the cost of processing. In the second chamber 66, intergrowths of sulfide minerals and quartz are separated, which are sent for additional crushing in order to open the intergrowths, and are sent back for processing. In the third chamber 6c, a concentrate of sulfide minerals is released, which is sent to grinding and further processing by flotation technology. The fourth chamber concentrate 6g, containing gold in an amount of at least 120 g / t, is sent for leaching. The concentrate of the fifth chamber 6d, containing sufficiently high gold contents, is sent to the area of gravity lapping of gold-containing concentrates. The gold nuggets that remained on the conveyor belt are a concentrate sent for refining.

EXAMPLE 4

Consider the separation of clinker zinc production (see figure 4). In the production of zinc metal, slag clinker is formed, which is a mixture of unreacted coke and aluminosilicate block. This product is quite difficult to dispose of, as it contains up to 20% of coke, which can ignite, and also does not allow the use of clinker as part of building materials. After cooling, the clinker is crushed to a size of less than 20 mm, and enters the conveyor, made in the form of a drum 20 with a mesh of 1.0 mm. Above the conveyor 20, one chamber 6a is installed with a size of 1000x100 mm, with an air stream configured to extract coke. A large difference in the density of coke and slag makes it possible to obtain high-quality separation of materials in a wide range of particle sizes.

Thus, the inventive method allows you to effectively carry out pneumatic separation of various mineral raw materials.

Claims

Claim

1. A method of pneumatic enrichment of mineral raw materials, comprising placing the enriched raw material on an air-permeable surface intersecting a vertical chamber with an upward air flow, lifting light fractions from the air-permeable surface, which are then transferred to the gravitational deposition chamber by air flow, characterized in that it is air-permeable the surface is made in the form of a conveyor of one or several vertically installed vertical chambers passed below the level of the lower base each of which is for this airflow is formed bulk layer of a predetermined pseudo-density particles, which enter and pass freely therethrough particles of lower density, and then the ascending air current is transferred from the camera in the vertical hydrochloric gravitational deposition chamber.

2. The method according to claim 1, characterized in that the air flow rate in each of the vertical chambers is adjustable.

3. The method according to claim 1, characterized in that the air velocity profile inside each of the vertical chambers is fixed.

4. The method according to claim 1, characterized in that the air velocity profile inside each of the vertical chambers is set variable.

5. The method according to claim 1, characterized in that the cell size of the breathable conveyor is set constant over its entire surface.

6. The method according to claim 1, characterized in that the cell size of the breathable conveyor is adjustable from chamber to chamber.

7. The method according to claim 1, characterized in that the speed of the conveyor is adjustable.

8. The method according to claim 1, characterized in that the conveyor speed is set intermittently.

9. The method according to claim 1, characterized in that the position of the conveyor relative to the level of the lower part of the chambers is adjustable.

10. The method according to claim 1, characterized in that the conveyor is made in the form of a moving belt conveyor

11. The method according to claim 1, characterized in that the conveyor is made in the form of a vibratory conveyor.

12. The method according to claim 1, characterized in that the conveyor is made in the form of a rotating disk.

13. The method according to claim 1, characterized in that the conveyor is made in the form of a rotating drum with a horizontal axis, over which vertical chambers are installed along its axis.