Phosphoric acid mill tailing circulating treatment system

Abstract

The invention discloses a phosphoric acid mill tailing circulating treatment system which comprises a tailing collecting trough, a stirrer, a tailing pump, a tailing thickener, a dense tailing pump, a tailing tank, a belt filter, a vacuum pump, a finished product acid liquor sealing tank, a tailing hopper and a phosphogypsum slag warehouse. Backwater of the tailing thickener overflows into a sewage circulating pool below the thickening pool to be recycled, and washing sewage of the belt filter and washing sewage of the tailing hopper are pumped into the tailing thickener to be recycled again; the material distributor of the belt filter is beneficial to uniform distribution of slurry and easy to clean; the double-overflow-weir structure of the tailing thickener smooths the overflow process and increases the sedimentation area, and the double-rake-arm structure simultaneously stirs tailings inside and at the bottom of the tailing thickener, so that the discharge port of the tailing thickener is prevented from being blocked. A ball mill is not adopted, doping and introduction of impurities of ball milling balls are avoided, internal and external double circulation of washing sewage is achieved, the utilization rate of tailings is increased, and the ecological environment is protected.

Description

Technical Field

[0001] The invention relates to the technical field of phosphoric acid beneficiation, and in particular to a phosphoric acid beneficiation tailings circulation treatment system. Background Art

[0002] In the process of producing high-purity phosphoric acid from medium- and low-grade phosphate ore, the phosphate ore is separated into phosphate concentrate and tailings by flotation after crushing, grinding and flotation. The fine tailings produced by flotation are usually wet-discharged and pumped into the tailings pond for storage. This is the tailings treatment method widely used by most phosphate flotation plants. This wet discharge method not only has high investment costs for the construction of the tailings pond and occupies a large area, but also requires the installation of a booster pump and corresponding conveying pipelines, flood prevention and drainage facilities, and has high operating and maintenance costs. In contrast, using a thickener to concentrate the flotation tailings slurry and using a filtration device to separate the flotation tailings slurry into solid and liquid before dry-draining and dry-piling is a new method with good development prospects.

[0003] For example, the Chinese invention with the announcement number CN103611625A discloses a flotation tailings reprocessing system; including a flotation tailings processing system and a wastewater recovery system, wherein the flotation tailings processing system includes a feeding mechanism, a ball mill, a slurry pump, a 24 m thickener, a leaching device, an adsorption device, a filter, a water separator pump and a tailings pond in order from the input to the output of the ore; the wastewater recovery system consists of three parts, the first part is the wastewater in the tailings pond pumped to the high-level water pool through the recovery pool and then entering the ball mill, the second part is the wastewater in the filter pumped to the slurry pump, and the third part is the wastewater from the 24 m thickener pumped to the ball mill. This invention can well improve the utilization rate of mineral resources through the coordinated use of the flotation tailings processing system and the wastewater recovery system.

[0004] It can be seen from the above patents that the tailings, backwater, sewage, etc. after the reaction are not treated and utilized sufficiently in the tailings reprocessing system, and impurities from the ball mills are easily mixed into the ball mills during the use of the ball mills, resulting in more impurities in the liquid phase after filtration. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a phosphoric acid beneficiation tailings circulation treatment system.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A phosphate beneficiation tailings recycling treatment system comprises a tailings collecting trough, a mixer, a tailings pump, a tailings thickener, a thickening tailings pump, a tailings tank and a belt filter; the mixer comprises a stirring mechanism arranged at the bottom of the tailings collecting trough and a motor arranged above the tailings collecting trough and driving the stirring mechanism; the tailings in the tailings collecting trough are transported to the tailings thickener through the tailings pump; the tailings pump is respectively connected to the tailings collecting trough and the tailings thickener through pipelines; the tailings thickener releases the tailings after the tailings concentration is qualified and transports them to the tailings tank through the thickening tailings pump; the tailings thickener is connected to the thickening tailings pump and then to the tailings tank through a pipeline; the tailings in the tailings tank are transported to the belt filter through a pipeline; the return water of the tailings thickener overflows through a pipeline to a sewage circulation pool below the tailings thickener for recycling; the washing sewage of the belt filter is pumped into the tailings thickener by the sewage pump for recirculation.

[0007] Preferably, the tailings circulation treatment system provided by the present invention also includes a vacuum pump, a finished acid liquid sealing tank, a tailings hopper and a phosphogypsum slag storage, the vacuum pump is connected to and acts on the belt filter, the belt filter includes a slurry distributor and a gas-liquid separator, the gas-liquid separator is connected to the finished acid liquid sealing tank, the tailings hopper is arranged at the rear of the belt filter, and the phosphogypsum slag storage is connected to the tailings hopper via a tailings belt.

[0008] Preferably, the belt filter comprises a filter belt, a filter disc, a feed port, a washing device, a scraper, a cloth washing device, a gas-liquid separator, a switching valve, a driving device, a sewage collection tank, a vacuum pump and a deviation correction device. The filter belt is wound by filter cloth into an annular upper filter belt and a lower filter belt. The filter disc is arranged below the upper filter belt, the feed port is arranged at the starting end of the upper filter belt, the washing device is arranged above the upper filter belt, the scraper is arranged at the turning point of the upper filter belt in the horizontal and vertical directions, the cloth washing device is arranged at the starting end of the lower filter belt, the gas-liquid separator is arranged below the lower filter belt, a switching valve is arranged between the gas-liquid separator and the filter disc, the driving device is arranged between the upper filter belt and the lower filter belt and drives the filter belt to roll, the outlet of the cloth washing device is connected to the sewage collection tank, the vacuum pump is connected to the gas-liquid separator, the deviation correction device is arranged at the tail end of the lower filter belt, and a distributor is additionally arranged at the bottom of the feed port of the belt filter.

[0009] Preferably, the tailings thickener comprises an inner overflow weir, an outer overflow weir, a long rake arm, a short rake arm, a feed pipe, and a distributor. The inner overflow weir and the outer overflow weir form a double overflow weir structure and the overflow port height decreases successively from the inside to the outside. The long rake arm and the short rake arm form a double rake arm structure to simultaneously stir the tailings inside and at the bottom of the tailings thickener, and a distributor is arranged in the feed pipe.

[0010] Preferably, the washing wastewater from the tailings bucket is pumped into the tailings thickener by a wastewater pump for recirculation.

[0011] The beneficial effects of the present invention are: 1. The tailings are concentrated and filtered through the tailings thickener and belt filter to improve the utilization rate of tailings and protect the ecological environment; the return water of the tailings thickener overflows through the pipeline to the sewage circulation pool below the thickening tank for recycling, the washing sewage of the belt filter is pumped into the tailings thickener by the sewage pump through the sewage collection tank for recirculation, and the washing sewage of the tailings hopper is pumped into the tailings thickener by the sewage pump for recirculation, realizing internal and external double circulation; 2. The tailings recycling treatment system does not use a ball mill to avoid the incorporation and introduction of impurities from the milling balls. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0013] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0014] Figure 1 A schematic diagram of a phosphoric acid beneficiation tailings circulation treatment system proposed by the present invention; Figure 2 A schematic diagram of the structure of a tailings thickener in a phosphate beneficiation tailings circulation treatment system proposed by the present invention; Figure 3 A schematic diagram of the structure of a belt filter in a phosphoric acid beneficiation tailings circulation treatment system proposed by the present invention; Figure 1 As shown in: 1. Tailings collection trough, 2. Mixer, 3. Tailings pump, 4. Tailings thickener, 5. Tailings thickening pump, 6. Tailings tank, 7. Belt filter, 8. Vacuum pump, 9. Finished acid liquid sealing tank, 10. Tailings hopper, 11. Phosphogypsum slag storage; Figure 2 As shown in: 41, inner overflow weir, 42, outer overflow weir, 43, long rake arm, 44, short rake arm, 45, feed pipe, 46, distributor; Figure 3 As shown in: 701, filter belt, 702, filter plate, 703, feed port, 704, washing device, 705, scraper, 706, cloth washing device, 707, gas-liquid separator, 708, switching valve, 709, driving device, 710, sewage collection tank, 711, vacuum pump, 712, deviation correction device. DETAILED DESCRIPTION

[0015] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0016] 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 invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0018] It should be noted that similar reference numerals and letters tend to denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition and explanation in subsequent drawings.

[0019] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use, or the positions or positional relationships commonly understood by those skilled in the art, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connected" should be understood in a broad sense, for example, it 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] Reference Figure 1 The present invention discloses a phosphate beneficiation tailings recycling treatment system, comprising a tailings collecting trough 1, a mixer 2, a tailings pump 3, a tailings thickener 4, a thickening tailings pump 5, a tailings tank 6, and a belt filter 7 which are arranged in sequence; the mixer 2 is used to fully stir the tailings in the tailings collecting trough 1, the tailings pump 3 is used to extract the tailings from the tailings collecting trough 1 into the tailings thickener 4, the tailings thickener 4 releases the tailings after the tailings concentration is qualified, and transports the tailings to the tailings tank 6 through the thickening tailings pump 5, the return water of the tailings thickener 4 overflows through a pipeline to a sewage circulation pool below the tailings thickener 4 for recycling, and the tailings in the tailings tank 6 are transported to the belt filter 7 through a pipeline.

[0022] The tailings circulation treatment system provided by the present invention also includes a vacuum pump 8, a finished acid liquid sealing tank 9, a tailings hopper 10 and a phosphogypsum slag storage 11. The vacuum pump 8 is used to evacuate the belt filter 7, the finished acid liquid sealing tank 9 is used to store the finished acid filtered by the belt filter 7, and the tailings hopper 10 is used to hold the tailings filtered and cleaned by the belt filter 7, and transport it to the phosphogypsum slag storage 11 via a tailings belt.

[0023] In an optional embodiment, the tailings thickener 4 includes an inner overflow weir 41, an outer overflow weir 42, a long rake arm 43, a short rake arm 44, a feed pipe 45, and a distributor 46. The double overflow weir structure formed by the inner overflow weir 41 and the outer overflow weir 42 has an overflow port height that decreases from the inside to the outside, which increases the sedimentation area while making the overflow process smoother, and the tailings particles are more thoroughly immersed after multiple times; the long rake arm 43 and the short rake arm 44 form a double rake arm structure to simultaneously stir the tailings inside and at the bottom of the tailings thickener 4, which makes the stirring more sufficient and avoids clogging of the tailings thickener 4 outlet. A distributor 46 is arranged in the feed pipe 45 to evenly distribute the tailings slurry while avoiding the tailings slurry from directly impacting the long rake arm 43, the short rake arm 44 and the bottom of the tailings thickener 4, so as not to affect the operation law of the slurry fluid and the operation and service life of the double rake arm structure; the return water of the tailings thickener overflows through a pipe to the sewage circulation pool below the thickening tank for recycling.

[0024] In an optional embodiment, the belt filter 7 includes a filter belt 701, a filter disc 702, a feed port 703, a washing device 704, a scraper 705, a cloth washing device 706, a gas-liquid separator 707, a switching valve 708, a driving device 709, a sewage collection tank 710, a vacuum pump 711 and a correction device 712; the filter belt 701 is wound by filter cloth into an annular upper filter belt and a lower filter belt, which are used as filtering media; the filter disc 702 is used as a medium for vacuum suction and a medium for the filtrate to pass; the feed port 703 arranged at the starting end of the upper filter belt 701 is used for feeding tailings slurry, and a distributor is additionally arranged at the bottom of the feed port 703 to evenly distribute the tailings slurry on the upper filter belt 701 so that it is evenly flat and convenient for subsequent washing Avoid direct impact on the filter belt 701; the washing device 704 arranged above the upper filter belt 701 is used to spray the washing liquid on the tailings slurry for washing; the scraper 705 arranged at the horizontal and vertical turning points of the upper filter belt 701 is used to scrape off the filter cake and filter residue transported to it, the cloth washing device 706 is used to clean the filter cloth, the gas-liquid separator 707, the switching valve 708 and the vacuum pump 711 are used together to vacuum the filter disc 702 and separate the filtrate; the driving device 709 is used to drive the roller of the filter disc 702 and then drive the filter belt 701 to form a circulating filter belt; the sewage collection tank 710 is used to collect the washing sewage and pump it into the tailings thickener 4 for recirculation; the deviation correction device 712 is used to prevent the filter belt 701 from running off and folding.

[0025] The working process of this embodiment is as follows: After the tailings are fully stirred by the mixer 2 in the tailings collection trough 1, they are pumped into the tailings thickener 4 through the tailings pump 3 for concentration; Tailings thickener 4: The tailings slurry flows into the tailings thickener 4 through the feed pipe 45, flows to the distributor 46 for even distribution, and is stirred by the long rake arm 43 and the short rake arm 44. The long rake arm 43 mainly stirs the tailings inside the tailings thickener 4 to promote the sedimentation of the tailings, and the short rake arm 44 mainly stirs the tailings at the bottom of the tailings thickener 4 to avoid blockage of the bottom discharge port; after the first overflow, it enters the inner overflow weir 41 for the second sedimentation, and after the second overflow, it enters the outer overflow weir 42 for the third sedimentation. Then, the return water of the third overflow overflows through the pipeline to the sewage circulation pool below the thickening tank for recycling. The tailings slurry is pumped into the tailings tank 6 from the bottom discharge port by the thickening tailings pump 5, and then transported to the belt filter 7. The upper limit of the tailings tank liquid level is 5.5 meters.

[0026] Belt filter 7: The tailings slurry is fed from the feed port 703 to the bottom distributor for even distribution, and falls smoothly and gently onto the filter belt 701. The drive device 709 drives the filter disc 702 and then drives the filter belt 701 to convey the tailings slurry forward to form a circulating filter belt. While the tailings slurry is conveyed to the washing device 704 for washing, the vacuum pump 711 is turned on to evacuate the filter disc 702 through the gas-liquid separator 707. The tailings slurry is sucked by the dual action of its own gravity and vacuum suction. Solid-liquid separation is achieved; after three washings and vacuum filtration, the filter cake and filter residue are transported to the scraper 705, scraped off by the scraper 705 and transported to the tailings bucket 10, the filter belt 701 is recycled to the cloth washing device 706 to clean the filter belt 701, the washing wastewater enters the wastewater collection tank 710 and is pumped into the tailings thickener 4 for recirculation, the vacuum filtrate is pumped into the gas-liquid separator 707, and the separated filtrate is pumped into the finished acid liquid sealing tank 9 from the bottom outlet through the vacuum pump 8. The feed flow rate of tailings slurry should be controlled at 30 m 3 / h-100 m 3 / h to ensure the filtration volume; the moisture content of the tailings is less than 15%, and the vacuum pump pressure is -0.04 to -0.06 MPa.

[0027] Tailings bucket 10: The filter cake and filter residue of the belt filter 7 enter the tailings bucket 10, and the washed tailings are transported to the phosphogypsum slag reservoir 11 via the tailings belt. The washing wastewater is pumped into the tailings thickener 4 by the wastewater pump for recirculation.

[0028] Of course, the embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A phosphate beneficiation tailings circulation treatment system, comprising a tailings collection trough (1), a mixer (2), a tailings pump (3), a tailings thickener (4), a thickening tailings pump (5), a tailings tank (6), and a belt filter (7); The mixer (2) comprises a mixing mechanism arranged at the bottom of the tailings collecting trough (1) and a motor arranged above the tailings collecting trough (1) and driving the mixing mechanism. The tailings in the tailings collecting trough (1) are transported to a tailings thickener (4) via a tailings pump (3). The tailings pump (3) is connected to the tailings collecting trough (1) and the tailings thickener (4) via pipelines. After the tailings concentration reaches a qualified level, the tailings are discharged from the tailings thickener (4) and transported to a tailings tank (6) via a thickening tailings pump (5). The tailings thickener (4) is connected to the thickening tailings pump (5) and then connected to the tailings tank (6) via a pipeline. The tailings in the tailings tank (6) are transported to a belt filter (7) via a pipeline. Features: The return water of the tailings thickener (4) overflows through a pipeline to the sewage circulation pool below the tailings thickener (4) for recycling, and the washing sewage of the belt filter (7) is pumped into the tailings thickener (4) by a sewage pump for recirculation.

2. A phosphoric acid beneficiation tailings circulation treatment system according to claim 1, characterized in that: The tailings circulation treatment system also includes a vacuum pump (8), a finished acid liquid sealing tank (9), a tailings hopper (10) and a phosphogypsum slag storage (11), wherein the vacuum pump (8) is connected to and acts on the belt filter (7), the belt filter (7) includes a slurry distributor and a gas-liquid separator, the gas-liquid separator is connected to the finished acid liquid sealing tank (9), the tailings hopper (10) is arranged at the rear of the belt filter (7), and the phosphogypsum slag storage (11) is connected to the tailings hopper (10) via a tailings belt.

3. A phosphoric acid beneficiation tailings circulation treatment system according to claim 1, characterized in that: The belt filter (7) comprises a filter belt (701), a filter disc (702), a feed inlet (703), a washing device (704), a scraper (705), a cloth washing device (706), a gas-liquid separator (707), a switching valve (708), a driving device (709), a sewage collection tank (710), a vacuum pump (711) and a deviation correction device (712); the filter belt (701) is wound with filter cloth to form an annular upper filter belt and a lower filter belt; the filter disc (702) is arranged below the upper filter belt (701); the feed inlet (703) is arranged at the starting end of the upper filter belt (701); the washing device (704) is arranged above the upper filter belt (701); the scraper (705) is arranged at the water level of the upper filter belt (701); The cloth washing device (706) is arranged at the starting end of the lower filter belt (701), the gas-liquid separator (707) is arranged below the lower filter belt (701), a switching valve (708) is arranged between the gas-liquid separator (707) and the filter disc (702), the driving device (709) is arranged between the upper filter belt and the lower filter belt and drives the filter belt (701) to roll, the outlet of the cloth washing device (706) is connected to a sewage collection tank (710), the vacuum pump (711) is connected to the gas-liquid separator (707), and the deviation correction device (712) is arranged at the tail end of the lower filter belt (701); a distributor is additionally arranged at the bottom of the feed inlet (703) of the belt filter (7).

4. A phosphoric acid beneficiation tailings circulation treatment system according to claim 1, characterized in that: The tailings thickener (4) comprises an inner overflow weir (41), an outer overflow weir (42), a long rake arm (43), a short rake arm (44), a feed pipe (45), and a distributor (46); the inner overflow weir (41) and the outer overflow weir (42) form a double overflow weir structure, and the overflow port height decreases from the inside to the outside; the long rake arm (43) and the short rake arm (44) form a double rake arm structure to simultaneously stir the tailings inside and at the bottom of the tailings thickener (4); and the feed pipe (45) is provided with a distributor (46).

5. A phosphoric acid beneficiation tailings circulation treatment system according to claim 1, characterized in that: The washing wastewater in the tailings bucket (10) is pumped into the tailings thickener (4) by a wastewater pump for recirculation.

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