A comprehensive utilization process for "tailings-free" treatment of gold tailings

Abstract

The present invention provides a comprehensive utilization process for "tailings-free" gold tailings, which includes the following steps: feeding the gold flotation tailings into a high-efficiency hydrocyclone group for classification, feeding the underflow into a high-frequency linear dewatering screen for classification and dewatering to separate the coarse sand on the screen; the material under the screen and the overflow of the hydrocyclone flow by gravity to the hydrocyclone pump sump and then are pumped into a desliming hydrocyclone group to remove the fine slime, obtaining overflow fine slime and sand deposits; the sand deposits at the underflow of the desliming hydrocyclone group flow by gravity into a three-stage vertical ring high-gradient magnetic separation unit for strong magnetic separation to select magnetic substances and non-magnetic substances; the magnetic substances and the overflow fine slime are proportioned and flow by gravity into the pump sump and then are pumped to the fine tail filling system; the non-magnetic substances flow by gravity into the pump sump and then are pumped to a dehydration integrated machine for dehydration; the overflow water from the sand bin of the filling system flows by gravity back to the process for recycling or enters the production water storage tank, and can also be used for greening in the factory area or road sprinkling, with no wastewater discharged externally.

Description

Technical Field

[0001] The invention relates to the field of comprehensive utilization of metallurgical mine tailings, and in particular to a "tailing-free" comprehensive utilization process of gold tailings. Background Art

[0002] The gold output of a mining company has increased year by year, and the development quality and benefits have been continuously improved. There are 15 tailings ponds in use with a total storage capacity of 55.9 million m 3 The remaining storage capacity is less than 13 million m 3 ; The company produces about 5 million m3 of tailings annually 3 , the amount of tailings entering the pond is 3 million m 3 In recent years, the filling utilization rate is about 35%, and all gold companies are facing problems such as insufficient tailings storage capacity and expiration of service life. As the national environmental protection situation becomes increasingly tight, how to efficiently dispose of gold tailings has become a problem that restricts the sustainable development of enterprises.

[0003] The scale of the mine's beneficiation plant is 6000t / d, and the gold output is increasing year by year. The development quality and benefits are constantly improving. The company is facing problems such as insufficient tailings pond capacity and expiration of service life. Tailings utilization mainly adopts the method of underground filling of coarse particles and discharge of fine particles to the tailings pond for disposal. The underground filling volume accounts for only 40%-45%, and most of the tailings are discharged to the tailings pond for storage. The comprehensive utilization of tailings is an important issue that needs to be solved urgently for this gold mine.

[0004] The study found that the main mineral components in the tailings are gangue minerals such as quartz, feldspar, and calcite, and a small amount of impurities such as magnetic iron, iron oxide, titanium oxide, iron silicate, and iron sulfide. The tailings have a particle size of +0.15mm accounting for 33.18%, and a particle size of -0.038m accounting for 31.25%. The main chemical composition SiO2 content is 55-70%, K2O+Na2O is 7-10%, Al2O3 is 10-16%, and the main impurities Fe2O3 are 1-5%, TiO2 0.10-0.30%, and CaO 0.5-3%. The original tailings are calcined at 1200℃, and the whiteness is 8-15. The tailings have a high content of silicon dioxide and belong to the feldspar-quartz type pegmatite ore type, with a high recycling value. Summary of the invention

[0005] To solve the above problems, the present invention provides a "tailing-free" comprehensive utilization process for gold tailings, which achieves zero tailings discharge and realizes "tailing-free" comprehensive utilization of tailings through comprehensive recycling of feldspar, ferromagnetic materials and gold-containing mineral resources in gold tailings.

[0006] The technical solution of the present invention is:

[0007] A gold tailings "tailing-free" comprehensive utilization process comprises the following steps:

[0008] (a) Feed the gold flotation tailings into a high-efficiency hydrocyclone group for classification. The underflow is fed into a high-frequency linear dewatering screen for classification and dewatering to separate the coarse sand on the screen. The coarse sand is dehydrated and dried to make construction sand.

[0009] (b) The material under the screen in step (a) and the hydrocyclone overflow flow by gravity to the hydrocyclone pump sump and are then pumped into a desliming hydrocyclone group to remove fine mud, obtaining overflow fine mud and sand deposits.

[0010] (c) The sand deposits, which are the underflow of the desliming hydrocyclone group in step (b), flow by gravity into a three-stage vertical ring high-gradient magnetic separation unit for strong magnetic separation to select magnetic substances and non-magnetic substances.

[0011] (d) The magnetic substances obtained in step (c) and the overflow fine mud obtained from the desliming hydrocyclone in step (b) are proportioned and flow by gravity into the pump sump and are then pumped to the fine tail filling system for underground filling.

[0012] (e) The non-magnetic substances obtained in step (c) flow by gravity into the pump sump and are then pumped to a dewatering integrated machine (a combination device of a hydrocyclone and a dewatering screen) for dewatering. The hydrocyclone and the dewatering screen in the dewatering integrated machine form an internal closed-loop cycle; the product on the dewatering screen is feldspar concentrate, which is used as a ceramic raw material.

[0013] (f) The overflow water from the sand storage bin of the filling system flows back by gravity for process recycling or into the production water storage tank, and can also be used for factory greening or road watering, with no waste water discharged externally.

[0014] Preferably, in step (a), the screen hole size of the high-frequency linear dewatering screen is 0.15 * 0.15 mm to separate the +0.15 mm coarse sand on the screen.

[0015] Preferably, in step (b), the feed pressure of the hydrocyclone is 0.04 - 0.10 MPa to obtain -0.038 mm overflow fine mud and -0.15 - +0.038 mm sand deposits.

[0016] Preferably, in step (d), the mass ratio of the magnetic substances to the overflow fine mud is 1:3.

[0017] The beneficial effects of the present invention are as follows:

[0018] Through the process flow of "tailings classification and dewatering - direct sale of coarse sand - magnetic separation of feldspar from medium sand for sale - proportioning of medium and fine tails for underground filling", the present invention can improve the utilization rate of tailings, reduce the tailings discharge, achieve energy conservation and emission reduction, alleviate the safety and environmental protection problems of tailings stacking, and has great significance for maintaining and improving the ecological environment, improving the utilization rate of mineral resources, and promoting the sustainable development of mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the process flow chart of the present invention. Detailed implementation manners

[0020] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0021] Embodiment

[0022] As Figure 1 shown, this embodiment includes the following steps:

[0023] (a) Feed the gold flotation tailings into a high-efficiency cyclone group for classification. The model of the high-efficiency cyclone group is FX610-GT*3. The underflow is fed into a high-frequency linear dewatering screen for classification and dehydration. The model of the high-frequency linear dewatering screen is 2ZKX2445, and the size of the sieve holes is 0.15*0.15 mm. The coarse sand separated on the sieve is used as construction sand, and the yield is 33.18%.

[0024] (b) The material under the sieve in step (a) and the overflow of the cyclone in step (a) flow by gravity to the cyclone pump sump and are then fed into a desliming cyclone group by a pump to remove fine mud. The feed pressure of the cyclone is 0.04 - 0.10 MPa, obtaining -0.038 mm overflow fine mud and -0.15 to +0.038 mm sand deposits. The yield of the -0.038 mm overflow fine mud is 31.25%, and the yield of the -0.15 to +0.038 mm sand deposits is 35.57%.

[0025] (c) The underflow of the desliming hydrocyclone group in step (b), the -0.15 to +0.038 mm sand, flows by gravity into the three-stage vertical ring high-gradient magnetic separation unit for strong magnetic separation to separate magnetic substances from non-magnetic substances. Vertical ring high-gradient magnetic separators are used for all three stages of magnetic separation operations, and the gap between the medium rods is 0.15 mm. The background magnetic field intensity of the first-stage magnetic separation operation is 0.6 ± 0.1 T, preferably 0.6 T. The separated magnetic substances enter the tailings sedimentation tank, and the non-magnetic substances enter the second-stage magnetic separation operation. The background magnetic field intensity of the second-stage magnetic separation operation is 1.0 ± 0.1 T, preferably 1.0 T. The separated magnetic substances enter the tailings sedimentation tank, and the non-magnetic substances enter the third-stage magnetic separation operation. The background magnetic field intensity of the third-stage magnetic separation operation is 1.4 ± 0.1 T, preferably 1.4 T. The separated magnetic substances enter the tailings sedimentation tank, and the non-magnetic substances enter the non-magnetic material pump tank. The comprehensive yield of magnetic substances is 11.37%.

[0026] (d) The non-magnetic substances obtained in step (c) flow by gravity into the pump tank and are then pumped to a dewatering integrated machine (a combination device of a hydrocyclone + dewatering screen, the hydrocyclone model is FX150 - GX*14, and the dewatering screen model is ZKX2445) for dewatering. The hydrocyclone and the dewatering screen in the dewatering integrated machine form an internal closed-loop circulation. The product on the screen of the dewatering screen is feldspar concentrate, which is used as a ceramic raw material. The yield is 24.20%, K2O + Na2O is 8.20%, the Fe2O3 content is 0.10 - 0.24%, the TiO2 content is 0.04 - 0.08%, and after calcination at 1200 °C, the whiteness is 56.6.

[0027] (e) The -0.15 to +0.038 mm magnetic substances obtained in step (c) and the -0.038 mm overflow obtained from the desliming hydrocyclone in step (b) are proportioned (the mass ratio of -0.15 to +0.038 mm magnetic substances to -0.038 mm overflow is about 1:3), with a yield of about 42.62%. They flow by gravity into the pump tank and are then pumped to the fine tailings filling system, and are used for underground filling in combination with a newly developed self-developed slag-based fine tailings cementitious material.

[0028] (f) The overflow water from the sand storage bin of the filling system flows by gravity back to the process for recycling or enters the production reservoir, and can also be used for greening in the factory area or road watering, with no wastewater discharged externally.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance. In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, terms such as "set", "connected" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A comprehensive utilization process for "tailings-free" gold tailings, characterized in that, It includes the following steps: (a) Feeding the gold flotation tailings into a high-efficiency hydrocyclone group for classification, feeding the underflow into a high-frequency linear dewatering screen for classification and dewatering, separating the +0.15 mm coarse sand on the screen, dehydrating and drying the coarse sand to make construction sand, and the screen aperture size of the high-frequency linear dewatering screen is 0.15 * 0.15 mm; (b) The material under the screen in step (a) and the hydrocyclone overflow flow by gravity to the hydrocyclone pump sump and then are fed into a desliming hydrocyclone group by a pump to remove fine mud. The hydrocyclone feed pressure is 0.04 - 0.10 MPa, obtaining -0.038 mm overflow fine mud and -0.15 - +0.038 mm sand deposit; (c) The sand deposit at the underflow of the desliming hydrocyclone group in step (b) flows by gravity into a three-stage vertical ring high-gradient magnetic separation unit for strong magnetic separation to select magnetic substances and non-magnetic substances; (d) The magnetic substances obtained in step (c) and the overflow fine mud obtained from the desliming hydrocyclone in step (b) are proportioned and flow by gravity into the pump sump and then are sent to the fine tail filling system by a pump for underground filling. The mass ratio of the magnetic substances to the overflow fine mud is 1:3; (e) The non-magnetic substances obtained in step (c) flow by gravity into the pump sump and then are sent to a dehydration integrated machine composed of a hydrocyclone and a dewatering screen for dehydration. The hydrocyclone and the dewatering screen in the dehydration integrated machine form an internal closed-loop cycle; the product on the dewatering screen is feldspar concentrate, which is used as a ceramic raw material; (f) The overflow water from the sand bin of the filling system flows back for process recycling by gravity, or enters the production water storage tank, or is used for greening in the factory area, or is used for road watering, and there is no wastewater discharged externally.

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