Recovery method and recovery system for reverse flotation fine particle foam tail salt

Abstract

The invention provides a recovery method and a recovery system for reverse flotation fine particle foam tail salt, and belongs to the technical field of resource reutilization. According to the method, the foam tail salt is sequentially subjected to first mixing and stirring, second mixing and stirring, roughing and concentration, carnallite concentrate is obtained, and a collecting agent is added before the second mixing and stirring and the concentration. The recovery system comprises a buffer stirring barrel, a roughing stirring barrel, a roughing rotational flow-static microbubble flotation column and a concentration rotational flow-static microbubble flotation column which are connected in sequence. According to the method, two rotational flow-static micro-bubble flotation columns are adopted to form a one-roughing and one-fine process, foam products generated by the two rotational flow-static micro-bubble flotation columns are combined for tailing discarding, and underflow products of the fine selection rotational flow-static micro-bubble flotation columns are qualified carnallite concentrate products and can be returned for continuous utilization. The yield of the obtained carnallite concentrate is larger than or equal to 25%, the content of potassium chloride is larger than 17%, and the content of sodium chloride is smaller than 20%.

Description

Technical Field

[0001] The invention relates to the technical field of resource recycling, and in particular to a method and a system for recovering reverse flotation fine-grained foam tail salt. Background Art

[0002] Salt lake resources are unique resources. Potassium resources are the most mature in salt lake resource development. The potash fertilizer production process adopted by the Qarhan Salt Lake is mainly the reverse flotation-cold crystallization potash fertilizer production process. With the large-scale utilization of potash fertilizers and the rapid development of potash fertilizer companies, the production capacity of potash fertilizers has continued to increase, and potash fertilizer resources have obviously become insufficient in supply.

[0003] At present, potash fertilizer resources are in short supply and of complex quality. The efficiency of equipment has reached its limit, making it difficult to control product recovery rate and quality. At the same time, when the particle size of the original ore is coarse, coarse particles larger than 0.6mm are difficult to suspend in the flotation machine, resulting in a high sodium content in the bottom flow. For fine crystals with a particle size of less than 0.1mm, the flotation machine is difficult to recover, resulting in flotation indicators that are difficult to control, unstable production, and low product recovery rate. The technicians have conducted a large number of experimental studies through various means such as blending the original ore, adjusting the air intake of the flotation machine, stirring frequency, and adding flotation reagents in stages. The results are not ideal, and the technical bottleneck has always been difficult to break through.

[0004] The potassium content of tail salt discharged during potash fertilizer production is usually low, generally less than 2%, and there is currently no good method to reuse it for production. With the annual increase in potash salt mining, the depletion rate of potash resources is accelerating. How to improve the recycling of potassium resources has become a problem that must be faced in potash fertilizer production. The present invention provides a method and system for recovering fine-grained foam tail salt by reverse flotation, which realizes efficient recovery of foam tail salt and is of great significance. Summary of the invention

[0005] The object of the present invention is to provide a method and system for recovering fine-grained foam tail salt by reverse flotation, so as to solve the problem that fine-grained potassium chloride in fine-grained foam tail salt by reverse flotation in the prior art is difficult to recover.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for recovering fine-grained foam tail salt by reverse flotation, comprising the following steps:

[0008] The foam tail salt is sequentially subjected to a first mixing and stirring, a second mixing and stirring, a roughing selection and a fine selection to obtain a carnallite concentrate; a collector is added before the second mixing and stirring and before the fine selection.

[0009] Preferably, the foam tail salt has a fineness of -0.1 mm of more than 70%, a potassium chloride content of 3-6%, and a sodium chloride content of 60-70%.

[0010] Preferably, before the second mixing and stirring, the amount of collector added is 50-80 g / t.

[0011] Preferably, before the concentration, the amount of collector added is 30-60 g / t.

[0012] Preferably, the yield of the carnallite concentrate is ≥25%, the content of potassium chloride is >17%, and the content of sodium chloride is <20%.

[0013] The invention provides a reverse flotation fine-grained foam tail salt recovery system, comprising a buffer stirring barrel, a roughing stirring barrel, a roughing cyclone-static microbubble flotation column, and a fine cyclone-static microbubble flotation column which are connected in sequence.

[0014] Preferably, the roughing stirring barrel is connected to the roughing cyclone-static microbubble flotation column via a roughing feed pump.

[0015] Preferably, the roughing cyclone-static microbubble flotation column is connected to the fine cyclone-static microbubble flotation column via a fine feed pump.

[0016] Preferably, a roughing circulation pump is arranged between the top and the bottom of the roughing cyclone-static microbubble flotation column.

[0017] Preferably, a concentration circulation pump is provided between the top and the bottom of the concentration cyclone-static microbubble flotation column.

[0018] Beneficial effects of the present invention:

[0019] The invention adopts two cyclone-static microbubble flotation columns to form a coarse and a fine process. The flotation of fine-grained potassium chloride can be strengthened through different sorting processes of the flotation columns. The foam products generated by the two cyclone-static microbubble flotation columns are combined and tailings are discarded. The bottom flow products of the selected cyclone-static microbubble flotation columns are qualified carnallite concentrate products, which can be returned for further use, and the fine-grained potassium chloride that cannot be recovered by the flotation machine is recovered, the entrainment of sodium chloride in the potassium chloride concentrate is reduced, and the loss of potassium chloride resources is reduced.

[0020] Traditional flotation machines have long processes, low system recovery rates, and it is difficult to improve product quality. They also have high requirements for the stability of the original ore and strict requirements for process operation control. Errors in operation control can easily lead to reduced recovery rates and product quality. When traditional flotation columns are used to process high-density or coarse-grained ores, sedimentation is likely to occur at the bottom of the flotation column. The present invention breaks the conventional mineral processing technology, fully utilizes the characteristics of the flotation column, combines the unique advantages of inflation and self-absorption, and simplifies the flotation process and greatly improves the recovery rate by adding collectors, strengthening stirring, and strengthening circulation and recovery of flotation columns. The present invention has a low cost, a simple recovery system layout, and can be applied to the flotation of similar potassium salts. It has considerable economic and environmental benefits, and has significant technical advantages for difficult-to-handle fine-grained tailings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the flotation fine-grained foam tail salt recovery system of the present invention, wherein 1-buffer stirring barrel, 2-roughing stirring barrel, 3-roughing feeding pump, 4-roughing circulation pump, 5-roughing cyclone-static microbubble flotation column, 6-cleaning feeding pump, 7-cleaning circulation pump, 8-cleaning cyclone-static microbubble flotation column. DETAILED DESCRIPTION

[0022] The present invention provides a method for recovering fine-grained foam tail salt by reverse flotation, comprising the following steps:

[0023] The foam tail salt is sequentially subjected to a first mixing and stirring, a second mixing and stirring, a roughing selection and a fine selection to obtain a carnallite concentrate; a collector is added before the second mixing and stirring and before the fine selection.

[0024] In the present invention, the foam tail salt has a fineness of -0.1 mm of more than 70%, a potassium chloride content of 3-6%, and a sodium chloride content of 60-70%.

[0025] In the present invention, before the second mixing and stirring, the amount of the collector added is 50 to 80 g / t, preferably 60 to 70 g / t, and more preferably 65 g / t.

[0026] The collector described in the present invention is an amine collector. There is no particular limitation on the specific type of the amine collector, as long as it meets the requirements of the present invention. In the embodiment of the present invention, dodecylamine collector is preferably used.

[0027] In the present invention, there is no particular limitation on the stirring time and the stirring speed of the first mixing and stirring and the second mixing and stirring, as long as the mixing can be uniform.

[0028] In the present invention, before the concentration, the amount of the collector added is 30 to 60 g / t, preferably 40 to 50 g / t, and more preferably 45 g / t.

[0029] In the present invention, the yield of the carnallite concentrate is ≥25%, the content of potassium chloride is >17%, and the content of sodium chloride is <20%.

[0030] The invention provides a recovery system for reverse flotation fine foam tail salt, comprising a buffer stirring barrel, a roughing stirring barrel, a roughing cyclone-static microbubble flotation column and a fine cyclone-static microbubble flotation column which are connected in sequence.

[0031] In the present invention, the buffer stirring barrel can stabilize the mineral content of the foam tail salt and mix the slurries of different production systems, playing a certain role in recrystallization; the function of the roughing stirring barrel is to fully mix the different salts and collectors in the foam tail salt, and then separate them in the flotation process.

[0032] In the present invention, the roughing stirring barrel is connected to the roughing cyclone-static microbubble flotation column via a roughing feed pump.

[0033] In the present invention, the roughing cyclone-static microbubble flotation column is connected to the fine cyclone-static microbubble flotation column via a fine feed pump.

[0034] In the present invention, a roughing circulation pump is arranged between the top and the bottom of the roughing cyclone-static microbubble flotation column. The flotation power and bubble generation of the roughing cyclone-static microbubble flotation column are derived from the roughing circulation pump.

[0035] In the present invention, a selective circulation pump is arranged between the top and the bottom of the selective cyclone-static microbubble flotation column. The flotation power and bubble generation of the selective cyclone-static microbubble flotation column are derived from the selective circulation pump.

[0036] The recovery system and recovery method provided by the present invention are aimed at the foam tail salt in the reverse flotation process. A large amount of fine-grained potassium chloride in the original tail salt is lost in the foam phase. The potassium chloride is further enriched and recovered by the recovery system and recovery method of the present invention, and the recovered fine-grained potassium salt is returned to the crystallizer or returned to the flotation ore.

[0037] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0038] Example

[0039] After a roughing, a fine selection and a scavenging selection, the foam tail salt of the flotation machine is mainly -0.1mm fine salt particles, of which the KCl content is 5.53% and the NaCl content is 66.20%. The foam tail salt of the flotation machine is mixed and pumped into the buffer stirring barrel for the first mixing and stirring, and then flows to the roughing stirring barrel by gravity, and dodecylamine collector (addition amount is 65g / t) is added for the second mixing and stirring. After mixing, it is pumped to the roughing cyclone-static microbubble flotation column by the roughing feed pump. A roughing circulation pump (circulation pressure is 0.28MPa) is set between the top and bottom of the roughing cyclone-static microbubble flotation column. The flotation power and bubble generation of the roughing cyclone-static microbubble flotation column come from the roughing circulation pump, and foam and the first underflow product are generated after roughing.

[0040] Dodecylamine collector (addition amount is 45g / t) is added to the first underflow product, and pumped to the selected cyclone-static microbubble flotation column through a selected feed pump. A selected circulation pump (circulation pressure is 0.28MPa) is arranged between the top and the bottom of the selected cyclone-static microbubble flotation column. The flotation power and bubble generation of the selected cyclone-static microbubble flotation column come from the selected circulation pump. Foam and a second underflow product are generated after selection. The foams generated by roughing and selection are mixed as the final tail salt and discarded. The second underflow product is carnallite concentrate with a yield of 25%, of which the potassium chloride content is 17.05% and the sodium chloride content is 18.94%. The yield of the discarded tail salt is 75%, of which the potassium chloride content is 1.69% and the sodium chloride content is 81.95%.

[0041] Under the action of the reverse flotation fine-grained foam tail salt recovery method and recovery system of the present invention, the fine-grained tail salt that cannot be recovered by the flotation machine is further recovered, and the carnallite concentrate with a yield of 25% can be recovered after reselection. The quality of this part of carnallite concentrate is higher than the feed of the flotation machine, and the particle size is relatively fine. The carnallite concentrate can be concentrated and precipitated by a low-sodium thickener, and then separated by a low-sodium belt filter to obtain the refined salt of potassium chloride. The method strengthens the recovery of potassium chloride in fine-grained tail salt, not only improves the recovery rate of potassium chloride, but also reduces the influence of impurity sodium chloride. The recovered potassium chloride can bring significant economic benefits.

[0042] As can be seen from the above embodiments, the present invention provides a method and system for recovering fine-grained foam tail salt by reverse flotation, and the specific steps are: subjecting the foam tail salt to a first mixing and stirring, a second mixing and stirring, a roughing and a fine selection in sequence to obtain a carnallite concentrate, wherein a collector is added before the second mixing and stirring and before the fine selection. The recovery system of the present invention comprises a buffer stirring barrel, a roughing stirring barrel, a roughing cyclone-static microbubble flotation column, and a fine cyclone-static microbubble flotation column connected in sequence. Two cyclone-static microbubble flotation columns are used to form a roughing and fine process, and the foam products produced by the two cyclone-static microbubble flotation columns are combined and discarded, and the bottom flow product of the fine cyclone-static microbubble flotation column is a qualified carnallite concentrate product, which can be returned for further use. The carnallite concentrate yield obtained by the present invention is ≥25%, the potassium chloride content is >17%, and the sodium chloride content is <20%.

[0043] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for recovering fine-grained foam tail salt by reverse flotation, characterized in that: The steps include: The foam tail salt is sequentially subjected to a first mixing and stirring, a second mixing and stirring, a roughing selection and a fine selection to obtain a carnallite concentrate; a collector is added before the second mixing and stirring and before the fine selection.

2. The method for recovering reverse flotation fine foam tail salt according to claim 1, characterized in that: The foam tail salt has a fineness of -0.1 mm and a content of more than 70%, a potassium chloride content of 3-6%, and a sodium chloride content of 60-70%.

3. The method for recovering reverse flotation fine foam tail salt according to claim 1 or 2, characterized in that: Before the second mixing and stirring, the amount of collector added is 50-80 g / t.

4. The method for recovering reverse flotation fine foam tail salt according to claim 3, characterized in that: Before the above-mentioned concentration, the adding amount of the collector is 30-60 g / t.

5. The method for recovering reverse flotation fine foam tail salt according to claim 2 or 4, characterized in that: The yield of the carnallite concentrate is ≥25%, the content of potassium chloride is >17%, and the content of sodium chloride is <20%.

6. A recovery system for the method for recovering flotation fine-grained foam tail salt according to any one of claims 1 to 5, characterized in that: The method comprises a buffer stirring barrel, a roughing stirring barrel, a roughing cyclone-static microbubble flotation column and a fine cyclone-static microbubble flotation column which are connected in sequence.

7. The recovery system according to claim 6, characterized in that: The roughing stirring barrel is connected to the roughing cyclone-static microbubble flotation column through a roughing feed pump.

8. The recovery system according to claim 6 or 7, characterized in that: The roughing cyclone-static microbubble flotation column is connected to the fine cyclone-static microbubble flotation column through a fine feed pump.

9. The recovery system according to claim 8, characterized in that: A roughing circulation pump is arranged between the top and the bottom of the roughing cyclone-static microbubble flotation column.

10. The recovery system according to claim 7 or 9, characterized in that: A cleaning circulation pump is arranged between the top and the bottom of the cleaning cyclone-static microbubble flotation column.

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