Method for the integrated development of placer deposits

Abstract

FIELD: mining.SUBSTANCE: invention relates to the technology of developing gold-bearing placers and can be used in the development of natural placer deposits, primarily with fine, small and dispersed gold, and man-made mineral formations. The method of integrated development of placer deposits includes opening the deposit with excavator stopes oriented along the strike of the productive formation, movement of overburden rocks, extraction of sands and their gravity processing, carried out with the help of equipment for washing balance sands and finishing equipment of the placer processing section with the production of gold, separation of tailings and their placement in isolated zones, drilling of wells in isolated zones and borehole leaching of fine and plate gold. After opening, the peat is extracted above the productive layer in excavator passes, ahead of one of them, and is stored in bulk at the full height of the overburden dump. The overburden rocks are extracted selectively, dividing them into pebble-gravel rocks, gravel-sand rocks and clay rocks. Overburden rocks are moved into the mined-out space of a previously mined section or to a planned surface beyond the contour of the productive formation. The surface of the overburden dump is levelled with a bulldozer and isolated zones are formed – ditches for placing pebble-gravel rocks, gravel-sand rocks, clay rocks and sand washing tailings separately. In a separate ditch, a sequential layer-by-layer arrangement of clay rock, gravel-sand rock, pebble-gravel rock, and sand washing tailings is formed for subsequent borehole leaching, and then injection and pumping wells are formed. The accumulation of valuable components in the arrangement is controlled through pumping wells, either manually or automatically using robotic equipment linked to an automatic control system, depending on the volumes obtained. When valuable components have accumulated to a quantity sufficient for secondary processing, anodes are placed in injection wells and cathodes in pumping wells, and borehole leaching of gold, monazite, and chromium begins with environmentally friendly reagents in an electrodiffusion mode with electrosorption of complexes and residual reagents by sorbents placed in pumping wells.EFFECT: increase in technological and environmental efficiency due to the combination of the development system and the development of mass transfer processes.1 cl, 2 dwg

Description

[0001] The invention relates to the technology of developing placers and can be used in the development of natural placer deposits, primarily deep-seated complex and polymorphic with small nuggets and fine, flaky and dispersed gold, platinum and other valuable components.

[0002] A method for developing placers is known, which includes the removal of peat and the extraction of sand, carried out by means of mechanization with the washing of the extracted sand on industrial devices (see Shorokhov S.M. Technology and complex mechanization of the development of placer deposits. Moscow, Nedra 1973, 768 p.) [1].

[0003] The disadvantage of the known method is the low extraction of associated valuable minerals and the main metal, represented, in addition to gravity-concentrated forms, by difficult-to-extract forms, small nuggets and fine, flaky and dispersed gold and / or platinum, caused by its losses, both at the stage of extraction of gold-bearing placer sands and at the stage of their washing.

[0004] The closest to the claimed method is the method of combined development of placer deposits and man-made mineral formations, including the opening of the deposit with subsequent advanced cleaning extraction of balance sands and the formation of workings with local extraction of gold-bearing mineral mass with an increased content of valuable components, drilling injection wells between the workings, feeding through them, into the remaining low-productivity layer, primary activated leaching solutions for gold, producing productive solutions from them by standing in the low-productivity layer, collecting productive solutions by drainage, subsequent extraction of gold on a sorbent,after the first stage of gravitational processing of part of the balance sands and the formation of workings, the tailings from washing the balance sands with fine fractions of under-extracted fine and plate gold and the tailings from the placer gravity processing are placed in a waterproofed central zone of the working, along the perimeter of which a separating waterproofed dam with a window of sorption cassettes is formed, mating with a waterproofed section of the storage tank of productive solutions, while, in parallel with the subsequent stage of gravitational processing of part of the balance sands, solutions with active oxidizers for placer minerals are fed into injection wells drilled to the raft of the low-productivity formation, and then, after a technological pause - solutions containing gold-leaching reagents, while the productive solutions are collected from the low-productivity formation by means of their drainage in the direction of the nearest workings to the intermediate zone,located in front of the dividing waterproof dam and having waterproofed bulkheads and a waterproofed bottom, wherein after the accumulation of productive solutions above the level of the upper edge of the dividing waterproof dam, the productive solutions enter the waterproofed central zone of the working with leached tailings from washing balance sands and tailings from placer gravity processing, and the capacity of the solutions with active oxidizers is connected with injection wells and the waterproofed central zone of the working (see Russian Patent RU 2678344 C1, 28.01.2019. Method for the combined development of gold deposits from placers and man-made mineral formations) [2].,

[0005] The disadvantage of the known method is the low technological efficiency of its application, due to the need for external waste disposal and the likelihood of environmental damage due to the use of chemical reagents in the leaching process directly in the productive layer of placer sands.

[0006] The technical result of the proposed method is to increase the technological and environmental efficiency of developing placer deposits due to the complex sequential-periodic distribution of tailings accumulated after gravitational processing with their placement in ditches on the surface of the formed drainage layers with the cupping of clay rock as insulation during secondary localized processing.

[0007] The technical result is achieved due to the fact that in the method of integrated development of placer deposits, including the opening of the deposit by excavator stopes oriented along the strike of the productive formation, the movement of overburden rocks, the extraction of sands and their gravitational processing, carried out with the help of equipment for washing balance sands and finishing equipment of the concentrate processing area with the production of gold, the separation of tailings and their placement in isolated zones, the drilling of wells in isolated zones and borehole leaching of small and plate gold, after opening, peat is extracted above the productive formation in excavator stopes with an advance of one of them and stored in bulk at the full height of the overburden dump, the excavation of overburden rocks is carried out selectively with the division into pebble-gravel rocks, gravel-sand rocks and clay rocks,the overburden rocks are moved into the mined-out space of a previously completed stope or onto a planned surface beyond the contour of the productive formation, the surface of the overburden dump is planned with a bulldozer and isolated zones are formed - ditches for placing pebble-gravel rocks, gravel-sand rocks, clay rocks and sand washing tailings in them separately, in a separate ditch a sequential layer-by-layer arrangement of clay rock, gravel-sand rock, pebble-gravel rock and sand washing tailings is formed for subsequent borehole leaching, and then injection and pumping wells are formed, through pumping wells the accumulation of valuable components in the arrangement is controlled manually or in automatic mode by means of robotic equipment connected to an automatic control system, depending on the volumes obtained, when the valuable components accumulate to a quantity sufficient for secondary processing,Anodes are placed in injection wells, and cathodes in pumping wells, and borehole leaching of gold, monazite and chromium begins with environmentally friendly reagents in an electrodiffusion mode with electrosorption of complexes and residual reagents by sorbents placed in pumping wells.

[0008] The ability to form the required sequence of actions performed by the proposed means allows solving the stated problem, determines the novelty, industrial applicability and inventive level of the development.

[0009] The method for the integrated development of placer gold deposits is shown in the drawings.

[0010] Fig. 1 - diagram of the site of the placer deposit being developed; Fig. 2 - a ditch with layer-by-layer sequential placement of rock.

[0011] After opening the deposit, the placer deposit is developed simultaneously by at least two adjacent excavator passes oriented along the strike of the productive seam 1. The extraction of peat 2 in these passes is carried out ahead of the advance of the face of one of them, which makes it possible to extract and wash sand in the contours of the mined-out space 3. In this case, the main part of the peat 2 is extracted and stored in bulk to the full height of the overburden dump 4. The overburden rocks 5 are moved to the mined-out space 3 of a previously completed pass or, at the initial stage of development, on a leveled surface behind the contour of the productive seam 1. The surface of the overburden dump 4 is leveled by a bulldozer 6 and ditches 7 are formed to place the tailings of sand washing 8 in them. Washing, i.e.Gravity processing of the mined sands is carried out using equipment for washing balance sands and finishing equipment of the concentrate processing section 9. The accumulated tailings from washing placer sands 8, containing residual hard-to-recover forms of gold, primarily fine and lamellar, are stored in ditches 7 until the second stage of deposit development, when their secondary processing in formed ditches 10 with placed clay rocks 11, gravel-sand rocks 12 and pebble-gravel rocks 13 becomes profitable under economic conditions. The accumulation of valuable components is controlled manually when processing small volumes and - in automatic mode - by means of robotic equipment 14, linked to an automatic control system 15, when processing large volumes. Injection wells 16 and pumping wells 17 are formed in ditches 10.Preparation for borehole leaching is carried out by placing anodes 18 in injection wells 16 and cathodes 19 in pumping wells 17.

[0012] The method of integrated development of placer deposits is carried out as follows.

[0013] The placer deposit is mined along the strike of the productive seam 1. The main part of the peat 2 is extracted and stored in bulk to the full height of the overburden dump 4. The overburden rocks 5 are moved to the mined-out space 3. The surface of the overburden dump 4 is leveled by a bulldozer 6 and ditches 7 are formed to accommodate the tailings of the sand washing 8. Gravity processing of the mined sand is carried out using equipment for washing balance sands and finishing equipment of the concentrate processing section 9. Initially, a combined bulk and selective extraction of the overburden rocks 5 is carried out, separating them into predominantly pebble-gravel rocks 13, gravel-sand rocks 12 and clay rocks 11, followed by leveling. Local formation of ditches 10 is carried out with layer-by-layer sequential laying of clay rock 11, gravel-sand rock 12 and pebble-gravel rock 13.On the surface of pebble-gravel rock 13, washing tailings 8 of placer sands are placed with residual difficult-to-recover, primarily fine and plate-shaped gold and other valuable components, which, under the influence of atmospheric precipitation and gravitational action, move to the boundary of clay rock 11, where they form accumulations productive for subsequent leaching. When developing small volumes of washing tailings 8, accumulation control is carried out periodically manually through pumping wells 17. When developing large volumes, accumulation control is carried out in automatic mode by means of robotic equipment 14, linked to an automatic control system 15. Preparation for borehole leaching is carried out by forming injection wells 16 with the placement of anodes 18 in them and pumping wells 17 with the placement of cathodes 19 in them. The ions of dissolved gold thereby diffuse to the cathodes 19 and accumulate on the sorbents placed around them.Borehole leaching of gold, monazite, chromium and other valuable components is carried out using environmentally friendly reagents in an electrodiffusion mode with electrosorption of complexes and residual reagents by sorbents placed in pumping wells 17.

[0014] The method ensures an increase in the technological and environmental efficiency of developing placer deposits due to the complex sequential-periodic distribution of tailings accumulated after gravitational processing with their placement in ditches on the surface of the formed drainage layers with a cover of clay rock as insulation.

Claims

A method for the integrated development of placer deposits, including stripping the deposit with excavator stopes oriented along the strike of the productive formation, moving the overburden, extracting sand and its gravitational processing, carried out with the help of equipment for washing balance sands and finishing equipment of the concentrate processing section with the recovery of gold, separating tailings and placing them in isolated zones, drilling wells in isolated zones and borehole leaching of fine and plate gold, characterized in that after stripping, peat is extracted above the productive formation in excavator stopes with an advance of one of them and stored in bulk at the full height of the overburden dump, the removal of overburden is carried out selectively with division into pebble-gravel rocks, gravel-sand rocks and clay rocks,the overburden rocks are moved into the mined-out space of a previously completed cut or onto a planned surface beyond the contour of the productive formation, the surface of the overburden dump is planned with a bulldozer and isolated zones are formed - ditches for placing pebble-gravel rocks, gravel-sand rocks, clay rocks and sand washing tailings in them separately, in a separate ditch a sequential layer-by-layer arrangement of clay rock, gravel-sand rock, pebble-gravel rock and sand washing tailings is formed for subsequent borehole leaching, and then injection and pumping wells are formed, through pumping wells the accumulation of valuable components in the arrangement is controlled manually or in automatic mode by means of robotic equipment connected to an automatic control system, depending on the volumes obtained, when the valuable components accumulate to a quantity sufficient for secondary processing,Anodes are placed in injection wells, and cathodes in pumping wells, and borehole leaching of gold, monazite and chromium begins with environmentally friendly reagents in an electrodiffusion mode with electrosorption of complexes and residual reagents by sorbents placed in pumping wells.

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