RU2675807C2 - Method of sorting rocks - Google Patents

Abstract

FIELD: minerals.SUBSTANCE: invention relates to the field of sorting various rocks of minerals according to their thermophysical properties and can be used in the separation of mineral particles, including diamond-containing rock. Method includes analyzing by thermal imaging and identifying particles containing valuable material, and separating particles containing valuable material according to the results of analysis by imaging. In this case, temperature distributions are recorded in the form of infrared images in the range from 0.74 to 14 mcm of electromagnetic wavelengths by scanning the surface of a deposit, mine, adits, trenches or drifts by means of a thermal imager, and the separation of valuable material is carried out according to the thermal characteristics of minerals recorded on infrared images, collecting the detected valuable material directly from the surface of the quarry, mine, tunnel, trench or drift of the developed field.EFFECT: increase in the efficiency of differentiation of useful minerals directly from the surface of the open-pit, mine, adit of the mine being developed is achieved.1 cl, 12 dwg

Description

The invention relates to the field of mineral processing, and in particular to methods for enriching various mineral rocks by their thermophysical properties, and can be used in the separation of mineral particles, in which thermal conductivity and heat capacity are significantly different from gangue particles, for example, such as various native minerals (copper, gold and the like), including minerals of diamond-bearing rocks. The inventive method can be used at many stages of exploration, production and enrichment of minerals.

The claimed invention relates to a priority area for the development of science and technology "Technologies for environmentally sound development of deposits and mining" [Alphabetical index to the International Patent Classification in priority areas for the development of science and technology / Yu.G. Smirnov, E.V. Skidanova, S.A. Krasnov. - M.: PATENT, 2008 .-- p. 110], since the claimed method is environmentally friendly.

There are a number of contact methods using various devices for detecting diamonds and diamonds, for example, the method disclosed in the description of the patent of the Russian Federation 2011978, using the device for identifying diamonds and diamonds (RF patent 2011978, IPC 5 G01N 25/18, published on 04/30/1994) , in which the identification of diamond is carried out in a contact manner using an electronic circuit with a transistor.

The signs of the analogue method, coinciding with the essential features of the proposed method, is the purpose and use of physical exposure.

The known method using a device for the identification of diamonds and diamonds according to the patent of the Russian Federation 2011978 is very difficult for the industrial beneficiation of diamond ore. Other similar contact devices are also impossible to use in industrial separation (sorting) of diamonds from the rock containing them.

There are a number of methods, which are x-ray luminescent separation of diamonds from the original diamond-containing rock.

A known method, for example, is the luminescent separation of minerals from an enriched material (RF patent No. 2362635, IPC B07C 5/346 (2006.01), B03B 13/06 (2006.01), published July 27, 2009), using the luminescence of the extracted mineral arising under the influence of exciting radiation.

The signs of the analogue method, which coincides with the essential features of the proposed method, is the use of physical impact.

The disadvantages of this method are:

- firstly, not all mineral particles of a valuable component luminesce, and part of the gangue can also luminesce, giving a false signal, which reduces the separation efficiency;

- secondly, a complex system for processing the received response signals, which does not allow to obtain the required extraction of a valuable component from the source ore;

- thirdly, high energy costs;

- fourthly, the use of penetrating electromagnetic radiation is not safe.

A known method of separation of diamond-containing materials and a device for its implementation (RF patent No. 2366519, IPC B07C 5/346 (2006.01), B03B 13/06 (2006.01), G01N 23/00 (2006.01), published on 09/10/2009).

The signs of the analogue method, which coincides with the essential features of the proposed method, is the physical effect (irradiation in the x-ray range of electromagnetic waves) on the source material.

The disadvantages of this method are also:

- firstly, not all mineral particles of a valuable component luminesce, and part of the gangue can also luminesce, giving a false signal, which reduces the separation efficiency;

- secondly, a complex system for processing the received response signals, which does not allow to obtain the required extraction of a valuable component from the source ore;

- thirdly, high energy costs;

- fourthly, the use of penetrating electromagnetic radiation is not safe.

A known method that is implemented during operation of the luminescent separator for the enrichment of mineral raw materials and the separation device of the desired product for the separators (RF patent No. 2215586, IPC B03B 13/06, B07C 5/346, published 10.11.2003).

Signs of an analogue that coincide with the essential features of the proposed method are a method in which physical action (irradiation in a certain range of electromagnetic waves) is carried out on the source material.

The disadvantages of this method are, as mentioned above: firstly, a complex system for processing the received response signals, which does not allow to obtain the required extraction of a valuable component from the original ore; secondly, not all mineral particles of a valuable component luminesce, and part of the gangue can also luminesce; thirdly, high energy consumption; fourthly, the use of penetrating electromagnetic radiation is not safe.

Thus, all the ways in which X-ray luminescent separators work have a number of disadvantages:

- environmentally unsafe, since electromagnetic radiation is used adversely affecting living organisms;

- complex calculation of revealing a valuable component;

- high energy costs;

- not all diamonds glow under X-rays, since their luminescence is due to impurities (nitrogen and other impurities);

- in addition to diamonds, a number of minerals also shine under the X-ray (zircons, pyropes, halites, calcites, etc.), therefore, the methods of X-ray luminescent separation of NPO Burevestnik devices identify diamonds by the attenuation of their glow after irradiation with X-ray, which complicates the separation process;

- X-ray fluorescence separation methods require complex hardware design (protection of people and other living organisms from penetrating electromagnetic radiation, complex electronic circuits and other device elements).

Closest to the claimed method is a method for sorting the produced rock (RF patent No. 2401166, IPC B07C 5/342 (2006.01), G01N 33/24 (2006.01), published on 10.10.2010), in which the sorting is based on analysis by thermal imaging and identification of particles containing valuable material. For this, the coarse fraction of particles is exposed to some kind of heating and the coarse fraction is divided into particles containing, according to the analysis by thermal imaging, valuable material and particles that are relatively unproductive in terms of the content of valuable material.

The signs of the prototype, coinciding with the essential features of a variant of the proposed method according to p. 1 of the claims are:

- analysis by thermal imaging and identification of particles containing valuable material;

- the separation of particles containing the results of the analysis through the formation of images of valuable material.

The prototype method will not allow ore sorting with separation of valuable material directly on the surface of the deposit or in the mine, selecting valuable material from the surface of the adits, since for this according to the prototype formula the following sequence of steps is required: grinding, sorting and heating. This heating can be carried out only locally, over a large area, uniform heating is difficult to implement. Therefore, only a certain area will be heated and unevenly, that is, valuable particles will heat up differently, which will not contribute to their explicit selection in the received images in the infrared range of electromagnetic waves. In other words, there must be some kind of enclosed space for a given heating or a method with a device that evenly supplies heat to the ore surface, in which a heat source will uniformly heat valuable particles to a certain specific temperature, and not valuable particles to another significantly different temperature .

The signs of the prototype, coinciding with the essential features of a variant of the proposed method according to claim 3 of the claims are:

- grinding of mined ore;

- separation of particles by size;

- exposure to one of the particle fractions of a certain type of physical impact, followed by analysis by thermal imaging and identification of particles containing valuable material;

- separation of valuable material from the analyzed fraction of particles according to the results of the analysis by means of the generated images.

The disadvantage of the prototype is also the implementation of a particular heating, which requires unconditionally additional energy consumption. However, heating is not always acceptable, as the source ore may contain minerals that, when heated, release toxic or toxic substances. For example, coloradoite is a mineral contained in solidified magma (kimberlite pipe). When heated, this mineral releases deadly toxic fumes and dust. In addition, a kimberlite pipe in some cases contains a certain amount of oil. Oil vapors are also toxic, and when heated with ignition, even more toxic substances are released. The above substances can especially heat up during microwave operation, which is used for heating in the prototype. Also, heating is not acceptable when enriching other ores containing toxic minerals (cinnabar, auripigment, stibnite, torbornite, arsenopyrite, asbestos, galena, gutchinsonite, chalcanthite and others), since such minerals emit toxic and toxic chemicals.

The invention is aimed at creating an effective safe technology for sorting rocks containing valuable components such as diamonds, native metals (gold, copper and other similar metals) and minerals that differ significantly in thermophysical properties from waste rock. Moreover, the invention is aimed at creating a technology without energy consumption, which can be used both at the stages of production and at the stages of mineral processing.

The technical result of the claimed invention is to increase the efficiency of differentiation of useful minerals directly from the surface of the quarry, mine, adit developed deposits.

The technical result of the claimed invention is achieved by the fact that in the method of sorting the rock, including analysis by thermal imaging and identification of particles containing valuable material, and separating particles containing the results of the analysis by image formation of valuable material, according to the invention, the temperature distributions are recorded in the form infrared images by scanning the surface of a field, mine, adit, trench or drift through a thermal imager (Or other similar device), and the separation of valuable material carried on thermophysical characteristics minerals, fixed on the infrared images, the detected collecting valuable material directly to the surface of the quarries, mines, tunnels, trenches or drift fields being developed.

The inventive method is based on the difference in thermophysical parameters (thermal conductivity, heat capacity) of waste rock and emitted useful component (for example, diamonds, native metals and other mineral particles having differences in thermophysical parameters. Differences from the prototype prove the novelty of the proposed method.

The use of thermal imagers is widely known in the prior art in a number of areas of human activity (http://www.thermoview.ru/articles/primenenie/), such as construction, energy and electrical engineering, metallurgy and others.

However, in these industries, it is not known to use a thermal imager to sort rocks by quickly differentiating minerals directly from the surface of a quarry, mine, or adit of a developed mineral deposit using a thermal imager. Thus, the claimed method allows to obtain a new technical result, expressed in the ability to quickly select the large pieces of valuable material (mineral) in the early stages of development of a mineral deposit. For example, a large diamond mined at an early stage in a quarry (mine or anywhere else in the field) will not be broken into smaller diamonds in further technological operations. Therefore, the claimed method meets the condition of patentability "inventive step".

The invention is illustrated by graphic materials in the form of photographs obtained in the infrared range of electromagnetic waves, temperature profiles and flowcharts of the method technology.

In FIG. 1 and FIG. Figure 2 shows two equally sized weights in glass round jars with low sides located on an aluminum substrate.

In FIG. 1 shows a photograph of a sample of diamond-free material of kimberlite minerals with a particle size of 0.6 to 0.8 mm, and FIG. 2 - photograph of a sample of diamonds of the same size.

In FIG. 3 shows the temperature profile of the temperature change of diamond-free material along the line ab shown in FIG. 1 and obtained using the software of the Testo 885-2 thermal imager.

In FIG. 4 shows the temperature profile of the temperature change of diamonds along the line cd shown in FIG. 2 and obtained using the software of the Testo 885-2 thermal imager.

In FIG. 5 shows a photograph of particles: river pebbles 1 and copper particles 2 with an average size of 1.5 cm on an aluminum substrate.

In FIG. 6 shows the temperature profile of the temperature variation of river pebbles and copper particles along the line ef shown in FIG. 5.

In FIG. 7 shows a photograph of river pebble particles and copper particles in an open glass Petri dish located on an aluminum substrate, and average temperatures corresponding to the particles.

In FIG. 8 is a flowchart without forced cooling of a field surface.

In FIG. 9 is a process flow diagram with forced cooling of a field surface.

In FIG. 10 shows a photograph of diamonds 3 and diamond-free material 4, presented in the color palette of the Testo 885-2 thermal imager. Diamonds 3 are blue, and diamond-free material 4 is light blue.

In FIG. 11 shows a photograph in the color palette of the Testo 885-2 thermal imager (repeating the photograph of FIG. 5). River pebbles 5 are red, and copper particles 6 are blue.

In FIG. 12 is a photograph repeating the photograph of FIG. 7, but presented in the color palette of the Testo 885-2 thermal imager with the corresponding average particle temperatures.

The inventive method can be used already at the stage of geological exploration or at the stage of opening the initial rock of the field, since many mineral particles having significant differences in thermal properties can be detected on the open surface of the field by scanning it with a thermal imager and obtaining images in the infrared range of electromagnetic waves and corresponding to their processing in order to identify valuable components (see. Block diagram in Fig. 8), since insignificant blowing of the rock in the form of convectors th flow (draft, wind) leads to its cooling. The main options for technological schemes of the proposed method are shown in FIG. 8 and FIG. 9.

The method of sorting the rock is carried out by scanning the surface of the field, mine, adit, trench or drift through a thermal imager and selecting the discovered valuable material directly from the surface of the quarry, mine, adit, trench or drift of the developed field. In this case, the registration of temperature distributions in the form of infrared images is carried out in the range from 0.74 μm to 14 μm of electromagnetic wavelengths using a thermal imager, for example, the Testo 885-2 brand, and the valuable material is separated by the thermal characteristics of the minerals recorded on infrared images.

Examples.

We took two samples of the same weight, shown in FIG. 1 and FIG. 2, in glass round jars with low sides, located on an aluminum substrate. A sample of diamonds with a particle size of 0.6 to 0.8 mm in FIG. 2 looked on the screen of a thermal imager of dark blue color, and a sample of diamond-free material of minerals of a kimberlite pipe of the same size in FIG. 1 - light blue.

To simulate natural conditions at a temperature of 37 ° C, they were blown with a gentle stream of air with a temperature of 22-25 ° C from the fan. After 3 seconds, the temperature difference shown on the temperature profiles of FIG. 3 and FIG. 4. The average temperature of diamond-free material has become 34.2 ° C, and the average temperature of the diamond sample 33 ° C. When the thermal imager operates in a color scale, the temperature of the image of the hinges will differ in colors. Of course, this temperature difference is determined by the different thermal conductivity and heat capacity of the diamond-free material and diamonds, and its small value is explained by the fact that there are air gaps on the diamond and diamond-free material, which affect their cooling and temperature difference. In FIG. 3 shows the temperature profile of the temperature change along the line ab shown in FIG. 1. In FIG. 4 shows a temperature profile along line cd shown in FIG. 2. Such a temperature difference of diamond-free material and diamonds was observed using the Testo 885-2 thermal imager repeatedly, more than ten times. Similar results were obtained on a ThermoPro TP8S thermal imager.

The method can be carried out by simultaneous heating on the one hand and cooling on the other hand, which will lead to a greater temperature difference between valuable and not valuable pieces of rock. For example, a substrate along which a monolayer rock flow moves can be heated, and on top can be cooled, or vice versa - the substrate can be cooled, and the rock can be heated on top. You can only cool the rock from any side - from above, from below, from the side or in any other direction.

In FIG. Figure 5 shows photographs of particles: river pebbles 1 and copper particles 2 with an average size of 1.5 cm. Pebbles and copper particles were placed on an aluminum substrate and cooled with air at a temperature of 22-25 ° C by a fan to simulate natural conditions. At the initial temperature of the samples 37 ° C, after 10 seconds, the average temperature of river pebbles decreased to 36.6 ° C (they are shown by light gray particles in the photo), the average temperature of the substrate was 35 ° C, and the average temperature of copper particles (in the photo look black ) decreased to 28 ° C. In FIG. 11 in the color palette of the thermal imager, the difference in colors and their brightness for particles having a temperature difference after cooling is significant: pebbles 5 are red and copper 6 is blue-blue.

In FIG. 6 shows the temperature profile along line ef shown in FIG. 5 and obtained using the software of the Testo 885-2 thermal imager. In this case, when large rock particles are cooled, a large temperature difference is observed between copper particles and river pebble particles.

In FIG. Figure 7 shows the same river pebble particles, light and dark-colored copper particles, naturally heated at room temperature 37 ° C, in an open glass Petri dish. A Petri dish was placed on an aluminum plate with an average temperature of -9 ° C to simulate natural conditions in the spring, when the soil is frozen, and the air temperature is high. In this photograph, copper particles and river pebbles clearly differ in color and temperature. After 7 seconds, the average temperature of the pebbles was set at about 29 ° C, and for copper particles, the average temperature was 9.9 ° C. This example is the most informative for the implementation of the proposed method under various natural conditions. For each particle shown in the photograph, its average temperature is given. For example, the average temperature of the largest pebble particle is 36.6 ° C, and the temperature of the smallest particle is 21.5 ° C. The largest copper particle has an average temperature of 14.6 ° C, and the smallest copper particle has an average temperature of 4.6 ° C. Large particles have a smaller ratio of surface area to volume, which contributes to a slower cooling. This temperature scatter shows that, firstly, for particles closer in their thermophysical properties, the initial rock should first be sorted by size, shape and other geometric parameters, and secondly, the difference in the size of the starting particles will not affect the detection of mineral particles having significant differences in thermophysical properties from another rock. In this example, copper particles having significant differences in thermophysical properties compared with river pebbles can easily be separated from waste rock. Since copper, in comparison with river pebbles, has a very high thermal conductivity and low heat capacity. The specific heat capacity of copper is 0.385 kJ / (kg⋅K), and the specific heat of this river pebble is 0.7-0.9 kJ / (kg⋅K). The thermal conductivity of copper is 401 W / (m⋅K), and the thermal conductivity of this river pebble is 2-4 W / (m⋅K). For diamonds, a similar temperature difference with waste rock in photographs taken in the infrared range of electromagnetic waves will be more significant, since the thermal conductivity of diamond is 1000-2600 W / (m⋅K) with a specific heat of 0.502 kJ / (kg⋅K) .

Claims (1)

A method of sorting rocks, including analysis by thermal imaging and identification of particles containing valuable material, and separating particles containing, according to the results of analysis by image formation, valuable material, characterized in that temperature distributions are recorded as infrared images in the range from 0.74 up to 14 microns of electromagnetic wavelengths by scanning the surface of a field, mine, adit, trench or drift through a thermal imager, and the separation of valuable of material carried on thermophysical characteristics minerals, fixed on the infrared images, the detected collecting valuable material directly to the surface of the quarries, mines, tunnels, trenches or drift fields being developed.

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