RU2294800C1 - Method of dressing of the base gold-quartz and gold-sulfide-quartz ores localized in the black shale rocks - Google Patents

Abstract

FIELD: mineral resource industry; methods of the complex reprocessing and dressing of natural minerals.

SUBSTANCE: the invention is pertaining to the complex reprocessing and dressing of the natural minerals and may be used for production of the concentrate of the gold-bearing ores localized in the black shale rocks, for example, of Muruntau and Sukhoy Log fields. The method of dressing of the base gold-quartz and gold-sulfide-quartz ores localized in the black shale rocks includes the ore reduction in the jaw breaker, the first screening, additional reduction, the second screening, the grading of the mesh minus in the hydrocyclones, the third screening and the centrifugal concentration. During the first screening separate the material with coarseness -200+100, -100+50, -50+25 and -25 mm. The grades -200+100, -100+50, -50+25 mm are subjected to the individual optical sorting with separation into the concentrate of the fragments having the quartz inclusions of the small ptygmatic veins and-or fringes of the magnesia- ferriferous carbonate with the linear size exceeding 2 mm. The produced concentrate of the optical sorting is additionally reduced and subjected to the second screening sequentially by the sifters with the size of the bolters of 5 mm and 1.5 mm. At that the oversize fraction with the coarseness of +5 mm is subjected to the additional reduction within the closed cycle in the impactor, and the mesh minus is subjected to the dressing in the Nelson centrifugal concentrators. At that the material with the coarseness of -1.5 mm is concentrated in the first concentrator, the tailings of which are subjected to the third screening by the screen with the size of the bolter of 0.5 mms, and the mesh minus of -0.5 mm is fed to the inlet of the second concentrator. The tailings of the second concentrator are sorted class in the hydrocyclones, the sands of which concentrated in the third concentrator, which tailings are combin with the oversize fraction of the second +1,5 mm and the third +0,5 mms screening, subject to the selective reduction and feed in the inlet of the first concentrator. At that the concentrates of the first, second and third concentrators are combined for the subsequent cyaniding. The technical result of the invention is the increased extraction of gold and the increased efficiency of dressing of the base off-balance gold-quartz and ores and gold-sulfide-quartz ores localized in the black shale rocks, the expansion of a raw-material base of the working and designed adventures.

EFFECT: the invention ensures the increased extraction of gold, the increased efficiency of dressing of the base off-balance gold-quartz and gold-sulfide-quartz ores localized in the black shale rocks, as well as the expansion of the raw-material base of the working and designed adventures.

5 cl, 1 dwg

Description

The invention relates to integrated processing and mineral processing and can be used to obtain a concentrate from gold-bearing ores localized in black shale rocks, for example, deposits Muruntau and Sukhoi Log.

It is known that in gold-quartz and gold-sulfide-quartz ores gold is represented by its native form and is concentrated in the interstices of quartz aggregates and in sulfides. The total sulfide content in the form of predominantly pyrite and arsenopyrite does not exceed 2-3% (see, Sharov G.N. et al. Technology for the extraction of precious metals from ores from deposits of the main geological and industrial types. Book 2. Moscow-Kemerovo, 2002). The thickness of the quartz veins, with which sulfides and native gold are associated, ranges from 2 to 20 mm. Bedrock, as a rule, has a dark color, which makes it possible to carry out photometric dressing of very poor ores (gold content 0.5-0.95 g / t) (see, for example, Mokrousov V.A., Lileev V.A. Radiometric beneficiation of non-radioactive ores. M.: Nedra. 1979, p.119-121). Means are described for sorting gold-bearing ores not only by the “light-dark” feature, but also by the halo of light scattering from quartz inclusion (SU 939085, Enin, 06/30/1982; US 4600105, Van Zyl et al., 07/15/1986), and also according to the color characteristics of local zones (RU 2215585, INTEGRA GROUP, 10.11.2003). However, due to the low power and low density of quartz streaks with sulfides and gold, optical sorting does not allow obtaining a concentrate in which the gold content is sufficient for gravity enrichment.

Gold extraction technology usually involves gravitational extraction of the largest gold and cyanidation of the tails of gravity concentration followed by extraction of gold from the cyanide solution by cementation on zinc dust or sorption on activated carbon (see, for example, V.V. Khabirov et al., Advanced mining technologies and processing of gold-containing raw materials. - M .: Nedra, 1994, p. 36-37, p. 55, 68-70, 77). The disadvantage of this technology is the high toxicity of cyanides, which requires special measures during their transportation and storage, as well as significant environmental costs.

A known method for the enrichment of gold-bearing ores, including crushing ore, screening of crushed ore, the classification of the sublattice product in hydrocyclones to obtain sand and drain, the sublattice product before classification in hydrocyclones is finished to a particle size of -1 mm Before centrifugal enrichment, material with a grain size of +0.8 mm is isolated, before thickening the drain from it by preliminary separation in hydrocyclones, sands are isolated that are subjected to additional centrifugal enrichment, and centrifugal enrichment of sands and tailings of additional centrifugal enrichment are sent to grinding, separating them with additional classification in hydrocyclones discharge directed to thickening together with the preliminary separation drain in hydrocyclones, while grinding is carried out jointly of material with grain size 0.8 mm and the milled product is recycled to the classification into undersize hydrocyclones (RU 2211730, Fedotov et al, 10.09.2003 -. closest analog). The disadvantage of this method is the need to grind the entire enriched rock mass, which for poor ores, including the processing of concentrate and refining, causes unproductive costs that overlap the market value of the extracted metal.

The purpose of the invention is to increase the efficiency of enrichment of poor, off-balance gold-quartz and gold-quartz-sulfide ores localized in black shale rocks, expanding the raw material base of existing and planned mining enterprises.

The technical result of the invention is to reduce the volume of ground rock mass of poor gold-quartz and gold-quartz-sulfide ores localized in black shale rocks by eliminating a significant part of the shale component poor in gold at the stage of large crushing and increasing gold recovery at the stage of gravity concentration.

The technical result is achieved by the fact that the method of beneficiation of gold-quartz and gold-sulfide-quartz ores localized in black shale rocks includes crushing ore in a jaw crusher, first screening, finishing, second screening, classification of the undergrate product in hydrocyclones, third screening and centrifugation . In the process of the first screening, material with a particle size of -200 + 100, -100 + 50, -50 + 25 and -25 mm is isolated. Classes -200 + 100, -100 + 50, -50 + 25 mm are subjected to separate optical sorting with the selection of pieces having quartz inclusions of the type of pigmatite veins and / or rims of magnesian-ferrous carbonate with a linear size exceeding 2 mm into a concentrate. The obtained optical sorting concentrate is subjected to fine refinement and second screening sequentially on screens with a sieve size of 5 mm and 1.5 mm, while the oversize product with a grain size of +5 mm is subjected to complete refinement in a closed cycle in a rotary crusher, and the under-sieve product is enriched in centrifugal Nelson concentrators . Moreover, material with a grain size of -1.5 mm is enriched in the first concentrator, the tails of which are subjected to third screening on a screen with a sieve size of 0.5 mm, and the under-sieve product of -0.5 mm is fed to the inlet of the second concentrator. The tails of the second concentrator are classified in hydrocyclones, the sands of which are enriched in the third concentrator, the tails of which are combined with the sieve products of the second +1.5 mm and the third +0.5 mm screening, subjected to selective grinding and fed to the input of the first concentrator, while the concentrate of the first, the second and third concentrators are combined for subsequent cyanidation.

The method can be characterized by the fact that the material obtained in the first screening process with a particle size of -25 mm is fed into the rotary crusher for further processing.

The method can be characterized by the fact that the slurry discharge of hydrocyclones is sent to screw separators, and the selected concentrate is combined with the concentrate of the first, second and third concentrators.

The method can also be characterized by the fact that the hydrocyclone discharge pulp is subjected to ultrasonic treatment in a rotary pulsation apparatus in a single loading mode, and also by the fact that selective grinding is carried out in centrifugal impact mills.

The method is based on experimental data established by the applicant. For poor gold-quartz and sulphide-quartz ores localized in black shale rocks, quartz inclusions have a size of the order of several millimeters (from 2 to 20-25 mm), and their shape can be curved (“pygmatite” veins), often the rims of magnesian-glandular carbonate at the contact of quartz veins with schists. These signs are confidently diagnosed by optical means, since black and its gradations with a gray background are convenient for constructing schemes for analyzing the surface of pieces of ore with the allocation of quartz inclusions. Thus, material that has virtually no useful component is excluded from the grinding process: half of the “soft” shale component, which interferes with the grinding of the solid quartz component in which gold is concentrated, is removed into the separation tailings. In addition, the use of special equipment for grinding optical sorting concentrate allows the implementation of selective ore crushing, which, as is known (see, for example, Selective destruction of minerals. - M .: Nedra, 1988, pp. 191-194, 244), allows to increase the degree of extraction of gold from gold-bearing ores, since quartz splits along the boundaries of grains to which gold precipitates are confined. For this purpose, centrifugal impact crushers (RU 2069097, Bilenko et al., November 20, 1996) or other destruction methods (RU 2191631, Kudryavtseva et al., October 27, 2002) can be used.

The subsequent processing technology is designed in such a way as to ensure the best disclosure of gold and prevent its overgrinding. To understand the reasons for the loss of gold with tails of gravity, the behavior of gold in the process of ore grinding is studied in detail. It was found that gold particles repeatedly pass through a mill with a circulating load, experiencing successive changes in physical properties, morphology and size (Amosov R.A., Pariy A.S. Methods of gravity testing of gold-bearing mineral raw materials // Mining Journal. 2003. No. 12) . First, the plastic particles of gold are crushed and rolled by grinding bodies into plates. Then the plates roll into microscopic “cigars”. At this stage, gold due to mechanical hardening loses its plastic properties and becomes brittle. The further stay of gold in the circulating load leads to the fact that the “cigars” break up into fragments of a scaly shape, which are practically not removed by jigging machines or centrifugal concentrators. A special study of the tails of gravitational enrichment using a scanning electron microscope showed that the gold in them is represented by flakes, the maximum size of which reaches 10-15 microns with a thickness of 1 micron or less.

Another important point is that in all gravitational apparatuses the selection of material is carried out not by specific gravity, but by hydraulic size. You cannot hold 0.1 mm gold and at the same time remove into the tails, for example, 5 mm quartz, although the specific gravity of the quartz is 7 times less than that of gold. Therefore, an important condition for effective separation is the preliminary classification of the material.

Taking into account the above-mentioned features of the behavior of gold in the selective grinding cycle in the gravitational part of the patented method, sequential extraction of coarse, fine and fine gold in three stages with preliminary classification of the enriched material and the use of screw separators at the last stage of gravity are provided, since screw separators extract plate particles of precious metals better than isometric, and their design is known (Ivanov V.D., Prokopyev S.A. Screw devices for enrichment ores and sands in Russia. Publishing house "Ducks." Moscow, 2000, s.146-147). It is advisable to process the discharge of the hydrocyclone before feeding it to the screw separators for better disclosure of thin gold in a rotary pulsation apparatus (see, for example, RU 2015730, Bogushevsky et al., 15. 07.1994).

The invention is illustrated in the drawing, which shows a diagram of the enrichment process.

The initial ore is crushed in a jaw crusher and is divided into classes -200 + 100 on a vibrating screen; -100 + 50; -50 + 25 and -25 mm. The +200 mm class is returned to the crusher. Classes -200 + 100; -100 + 50; -50 + 25 mm enter optical separation. The -25 mm class is tested at the stage of semi-industrial testing of a specific ore and, depending on the gold content, is either combined with tailings of optical sorting, or fed to a rotary crusher for refinement (shown by a dotted line in the diagram) and then to gravity concentration.

Optical separation is carried out taking into account the identification feature - the presence of quartz inclusions according to the type of pigmatite veins and / or rims of magnesian-ferrous carbonate with a linear size exceeding 2 mm (usually in the range of 2-25 mm). These signs are reliably determined by optical means of radiometric separation.

The optical separation concentrate after fine crushing in a cone crusher is fed to a vibrating screen with a mesh size of 5 mm. Oversize screening product +5 mm is subjected to selective destruction in a closed cycle by, for example, a rotary crusher and then returned to screening in the 5 mm class. The under-sieve product is fed to screening in the class of 1.5 mm; the under-sieve product is refined in a selective grinding mill, for example, centrifugal impact. An under-sieve of -1.5 mm is combined with the discharge of the mill, forming the power supply of the first 30-inch Nelson concentrator (KS) (the first stage of concentration), which helps to prevent overgrinding of large gold.

The tails of the Nelson concentrator are pumped for screening in the class + 0.5-0.5 mm, which closes the grinding cycle in combination with classifying hydrocyclones. An under-sieve product of -0.5 mm is sent to the second stage of gravity concentration, for which a 30-inch Nelson concentrator (CS) is also used, the over-sieve product is returned to the mill for regrinding.

Tails of secondary concentration are classified in hydrocyclones, for example, Krebs type g-MAX, which discharge less than 0.1 mm, which corresponds to about 15 microns for native gold. Sands of hydrocyclones are sent to a 30-inch Nelson concentrator (KS) to extract fine gold (the third stage of concentration). The tailings of the concentrator are returned to the mill for regrinding. Hydrocyclone discharge is processed by ultrasonic vibrations to better reveal gold in a rotary pulsation apparatus (RPA) in a single-load mode (to prevent its overgrinding) and is fed to a screw separator to extract thin plate gold. The tailings of the screw separator are the tailings of the process. Concentrates of all stages of concentration are combined and supplied to cyanide.

The combination of the described operations of the method allows cost-effective processing of poor ores with a gold content of 0.7-0.8 g / t and to obtain tailings containing 0.1-0.2 g / t - not higher than with vat cyanide. Extraction of gold at the stage of gravity is increased by 5-10% in comparison with the corresponding indicators achieved using the known method. In comparison: the extraction of gold according to the technology described in the closest analogue of RU 2211730 is 75%, and the extracted content is 0.75 g / t. The patented method allows cost-effective processing of poor ores, which, when using the known method, fall into the category of off-balance (substandard, non-industrial), and, thus, significantly expand the raw material base of existing and planned mining enterprises, in particular, Muruntau and Sukhoi Log deposits.

Claims (5)

1. The method of beneficiation of gold-quartz and gold-sulfide-quartz ores localized in black shale rocks, including crushing ore in a jaw crusher, first screening, finishing, second screening, classification of the under-sieve product in hydrocyclones, third screening and centrifugal concentration, during the first screening process, material with a particle size of -200 + 100, -100 + 50, -50 + 25 and -25 mm is isolated, classes -200 + 100, -100 + 50, -50 + 25 mm are subjected to separate optical sorting with the selection of pieces in a concentrate having quartz incl According to the type of pygmatite veins and / or rims of magnesian-ferrous carbonate with a linear size exceeding 2 mm, the obtained optical sorting concentrate is finished and subjected to second screening sequentially on screens with a sieve size of 5 mm and 1.5 mm, while the oversize product of + 5 mm is subjected to refinement in a closed cycle in a rotary crusher, and the under-sieve product is enriched in centrifugal Nelson concentrators, and material with a grain size of -1.5 mm is enriched in the first concentrator, the tailings of which are suspended they pass the third screening on a screen with a sieve size of 0.5 mm, and an under-sieve product of -0.5 mm is fed to the inlet of the second concentrator, the tails of the second concentrator are classified in hydrocyclones, the sands of which are enriched in the third concentrator, the tails of which are combined with the oversize products of the second +1 , 5 mm and a third +0.5 mm screening, are subjected to selective grinding and fed to the input of the first concentrator, while the concentrate of the first, second and third concentrators are combined for subsequent cyanidation. 2. The method according to claim 1, characterized in that the material obtained in the process of the first screening with a particle size of 25 mm is fed to the rotary crusher for further processing. 3. The method according to claim 1, characterized in that the hydrocyclone discharge pulp is sent to screw separators, and the separated concentrate is combined with the concentrate of the first, second and third concentrators. 4. The method according to claim 3, characterized in that the hydrocyclone discharge pulp is subjected to ultrasonic treatment in a rotary pulsation apparatus in a single loading mode. 5. The method according to any one of claims 1 to 4, characterized in that the selective grinding is carried out in centrifugal impact mills.