Lepidolite smelting slag recycling system

Abstract

The invention discloses a lepidolite smelting slag recycling system which comprises an original tailing hopper, a drying ball mill, winnowing equipment, purification equipment, a brickwork production system and an earthenware brick production system, and the discharging end of the original tailing hopper is connected with the feeding end of the drying ball mill; the discharging end of the drying ball mill is connected with the feeding end of the winnowing equipment and the bricklaying production system, and the discharging end of the winnowing equipment is connected with the feeding end of the purification equipment, the bricklaying production system and the earthenware brick production system. The method is applied to the technology of extracting lithium from mica in a large-scale and low-cost manner through washing, drying, sorting and roasting, and graded resource utilization of all components in the residual lithium slag is realized while thallium is solidified.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium-ion new energy, and in particular relates to a lithium mica smelting slag resource utilization system. Background Art

[0002] With the continued popularity of lithium-ion battery new energy, the production capacity of mica lithium extraction process has been greatly expanded. The tailings produced by the technology of roasting lithium mica to produce lithium carbonate have become an increasingly serious production problem due to its large output, high salt content, and a small amount of heavy metals (thallium, strontium, etc.), and have hindered the sustainable development of lithium-ion battery new energy. In the foreseeable future, proposing a lithium slag solution first and then developing lithium-ion battery new energy will become the only way for the development of mica lithium extraction technology.

[0003] CN117963948A "A Comprehensive Utilization Method for Lithium Slag from Lepidolite Smelting" discloses a multi-stage stirring and filtration-pressing thallium removal system, which effectively removes thallium from mica smelting slag. However, the system is ① complicated, with many devices but single functions; ② unilateral thallium removal, and a large amount of wastewater is generated in the process, requiring additional treatment; it is not economical and has weak functionality.

[0004] CN117361919A "Process for reducing sulfur and alkali in lithium slag, solid waste lithium slag and its application" discloses a lithium slag treatment method that reduces sulfur and alkali, and reduces acidic and alkaline substances in lithium slag by adding mixed acid. However, the system also has the following problems: 1) the system is cumbersome but has a single function; 2) it removes acid and alkali unilaterally without multi-level resource utilization; and it is not economical and feasible.

[0005] CN110482894B "A method for desulfurizing lithium slag powder using an acid method and its application in desulfurizing lithium slag powder" discloses a method for treating lithium slag using fly ash using an acid method to enhance the activity of lithium slag and reduce the sulfur trioxide content in the lithium slag by heat treatment, so that the lithium slag can be mixed with concrete. However, this technology has the following characteristics: ① High energy consumption and is not recommended for large-scale application.

[0006] CN114890692A "A lithium mica slag cement" discloses a technical process for producing cement from lithium slag, but the technology① only focuses on cement production and does not consider the problem of more SO3 and thallium elements in lithium slag, resulting in the mixing amount being unable to be increased and difficulty in large-scale application. Summary of the invention

[0007] In order to solve the above technical problems existing in the prior art, the present invention provides a lithium mica smelting slag resource system which can be used in multiple stages, is environmentally friendly and energy-saving, has low cost and can be mass-produced.

[0008] In order to solve the above technical problems, the present invention adopts the following technical scheme: a lithium mica smelting slag resource system, including an original tailings bucket, a drying ball mill, air separation equipment, a purification equipment, a bricklaying production system and a ceramic brick production system, the discharge end of the original tailings bucket is connected to the feed end of the drying ball mill, the discharge end of the drying ball mill is respectively connected to the feed end of the air separation equipment and the bricklaying production system, and the discharge end of the air separation equipment is respectively connected to the feed end of the purification equipment, the bricklaying production system and the ceramic brick production system.

[0009] The ceramic brick production system includes an air separation slag hopper, a clay hopper, a bentonite hopper, a first stirring and mixing device, a brick press, a tunnel kiln and a waste gas treatment device. The air separation device selects gypsum and drying slag. The drying slag discharge end of the air separation device is connected to the feed end of the air separation slag hopper. The discharge ends of the air separation slag hopper, the clay hopper and the bentonite hopper are all connected to the feed end of the first stirring and mixing device. The discharge end of the first stirring and mixing device is connected to the feed end of the brick press. The raw ceramic bricks produced by the brick press are transported to the tunnel kiln for firing. The waste gas of the tunnel kiln is treated by the waste gas treatment device and then discharged into the atmosphere.

[0010] The bricklaying production system includes a ball mill slag hopper, a slag hopper, a fly ash hopper, a drying equipment, a vertical grinding mill, an activator bin, a second stirring and mixing device and a bricklaying machine. The discharge end of the slag hopper is connected to the feed end of the drying equipment, the discharge ends of the drying equipment, the ball mill slag hopper and the fly ash hopper are all connected to the feed end of the vertical grinding mill, the discharge end of the vertical grinding mill, the discharge end of the air-selected gypsum of the air-selecting equipment and the discharge end of the activator bin are all connected to the feed end of the second stirring and mixing device, and the discharge end of the second stirring and mixing device is connected to the feed end of the bricklaying machine.

[0011] By adopting the above technical solution, compared with the prior art, the present invention has the following technical effects: 1) The present invention optimizes the process route, treats the mica smelting slag in stages, and recovers it in grades, so as to fix thallium in the smelting slag, recover calcium sulfate, and produce geopolymer cement products (brickwork), lightweight ceramic bricks, etc.

[0012] 2) Separate the components of lithium slag and utilize them at multiple levels to realize resource utilization; 3) Combining and nesting multiple process routes to form a systematic lithium slag treatment process to achieve zero solid waste emissions from lithium salt fields; ① Production line 1 is a lithium slag sorting and purification line, which uses a graded treatment method to achieve drying, air separation, purification, and ultimately produce calcium sulfate; ② The product of production line 2 is geopolymer cement products (brick building materials). After the dried slag is combined with other solid wastes (fly ash and slag), coarse gypsum and activator are added (the properties of lithium slag are changed by air separation of gypsum), and the lithium slag is further recycled through oligomer cement technology; ③ Production line 3 is the remaining slag after the lithium slag is processed by production line 1. Because the composition is different from the original lithium slag, bentonite and clay are used as additives. After being baked in the high-temperature flue gas at the rear end of the tunnel kiln of the lithium salt plant, lightweight ceramic bricks are made. This can also omit the extremely cold equipment of the lithium salt plant, utilize the waste heat and save the power consumption of the fan.

[0013] 4) The greatest effect of the present invention is to convert hazardous waste (smelting slag) into building materials resources, auxiliary materials resources, etc. A smelter with an annual output of 10,000 tons of lithium carbonate produces 1,000 tons of smelting slag per day. The storage and treatment cost of hazardous waste is about 2,000 yuan per ton. After conversion into building materials, about 900 tons of ceramic bricks (selling price is about 800 yuan per ton), 60 tons of crude calcium sulfide (selling price is about 150 yuan per ton), and 600 tons of high-density building bricks (selling price is about 700 yuan per ton) are produced. The required heat is provided by the flue gas of the original roasting system of the smelter. After using the present invention, 1,000 tons of smelting slag are produced every day. The economic benefit generated after the treatment of every 1,000 tons of smelting slag is 200+72+0.9+42=3.149 million yuan per day.

[0014] In summary, the present invention is applied to the lithium extraction technology of mica on a large scale and at low cost through water washing, drying, sorting and roasting. While fixing thallium, the various components in the remaining lithium slag are graded and utilized as resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention. DETAILED DESCRIPTION

[0016] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and examples.

[0017] like Figure 1 As shown, a lithium mica smelting slag resource utilization system of the present invention includes an original tailings bucket 1, a drying ball mill 2, an air separation device 3, a purification device 4, a bricklaying production system and a ceramic brick production system. The discharge end of the original tailings bucket 1 is connected to the feed end of the drying ball mill 2, the discharge end of the drying ball mill 2 is respectively connected to the feed end of the air separation device 3 and the bricklaying production system, and the discharge end of the air separation device 3 is respectively connected to the feed end of the purification device 4, the bricklaying production system and the ceramic brick production system.

[0018] The ceramic brick production system includes an air separation hopper 5, a clay hopper 6, a bentonite hopper 7, a first stirring and mixing device 8, a brick press 9, a tunnel kiln 10 and an exhaust gas treatment device 11. The air separation device 3 selects gypsum and dried slag. The dried slag discharge end of the air separation device 3 is connected to the feed end of the air separation hopper 5. The discharge ends of the air separation hopper 5, the clay hopper 6 and the bentonite hopper 7 are all connected to the feed end of the first stirring and mixing device 8. The discharge end of the first stirring and mixing device 8 is connected to the feed end of the brick press 9. The raw ceramic bricks produced by the brick press 9 are transported to the tunnel kiln 10 for firing. The exhaust gas of the tunnel kiln 10 is treated by the exhaust gas treatment device 11 and then discharged into the atmosphere.

[0019] The bricklaying production system includes a ball mill slag hopper 12, a slag hopper 13, a fly ash hopper 14, a drying equipment 15, a vertical grinding mill 16, an activator bin 17, a second stirring and mixing device 18 and a bricklaying machine 19. The discharge end of the slag hopper 13 is connected to the feed end of the drying equipment 15, and the discharge ends of the drying equipment 15, the ball mill slag hopper 12 and the fly ash hopper 14 are all connected to the feed end of the vertical grinding mill 16. The discharge end of the vertical grinding mill 16, the discharge end of the air-selected gypsum of the air-selecting equipment 3 and the discharge end of the activator bin 17 are all connected to the feed end of the second stirring and mixing device 18. The discharge end of the second stirring and mixing device 18 is connected to the feed end of the bricklaying machine 19.

[0020] A lithium carbonate production line produces 1000t / d of lithium slag with a moisture content of 20%. The present invention has the following three production lines for resource processing of lithium mica smelting slag.

[0021] Production line 1: The original lithium slag with a moisture content of about 20% is transported from the original tailings hopper 1 to the drying ball mill 2, where it is first dried and then forms 800t / d of dried lithium slag. The dried lithium slag is then ball milled for powder grinding. The powdered lithium slag 480t / d enters the air separation equipment 3, where crude calcium sulfate (gypsum) is selected according to the density / weight. The crude calcium sulfate can be used in production line 2 (64t / d of crude calcium sulfate) or sold after passing through the purification equipment 4 (6.6-7t / d of high-purity calcium sulfate).

[0022] Production line 2: slag (555t / d, water content 10%), 320t / d of lithium slag after drying and ball milling (water content less than 1%), and fly ash (138t / d) are put into vertical mill 16 for grinding (specific surface area not less than 500m 2 / kg), after grinding, it is mixed with the dried desulfurized gypsum (64t / d) and the activator in the second stirring and mixing device 18 according to the proportion, and after mixing, it enters the grinding and homogenization (water content is less than 2%), and the generated cementitious material is added with water and enters the bricklaying machine 19 (930t / d). According to different proportions, different geopolymer cementitious materials can be used to produce unburned bricks or blocks (high-density building materials).

[0023] Production line three: Lithium slag (473t / d), clay (126t / d) and Pengrun soil (18t / d) after air selection are mixed in the first stirring and mixing device 8 in proportion and then enter the brick press 9. After being pressed and formed, they enter the tunnel kiln 10 for preheating and roasting (the tunnel kiln 10 uses the lithium salt plant's own tunnel kiln 10 (roasting temperature is about 1000℃), but the kiln body needs to be modified, that is, the original extremely cold equipment is cancelled, and high-temperature flue gas is used to dry and roast (high-temperature flue gas is about 600-800℃) lightweight ceramic bricks) to form ceramic bricks. The exhaust gas generated by the tunnel kiln 10 is treated by the exhaust gas treatment device to meet the standards and is discharged into the atmosphere.

[0024] The above embodiments illustrate the basic principles and features of the present invention, but the above only illustrates the preferred embodiments of the present invention and is not limited to the embodiments. Under the inspiration of this patent, a person skilled in the art can make many forms of deformation and improvement without departing from the scope of protection of the present invention and the claims, which are all within the protection scope of the present invention. Therefore, the patent and protection scope of the present invention shall be subject to the attached claims.

Claims

1. A lithium mica smelting slag resource system, characterized by: It includes an original tailings bucket, a drying ball mill, air separation equipment, purification equipment, a bricklaying production system and a ceramic brick production system. The discharge end of the original tailings bucket is connected to the feed end of the drying ball mill, the discharge end of the drying ball mill is respectively connected to the feed end of the air separation equipment and the bricklaying production system, and the discharge end of the air separation equipment is respectively connected to the feed end of the purification equipment, the bricklaying production system and the ceramic brick production system.

2. A lithium mica smelting slag resource system according to claim 1, characterized in that: The ceramic brick production system includes an air separation slag hopper, a clay hopper, a bentonite hopper, a first stirring and mixing device, a brick press, a tunnel kiln and a waste gas treatment device. The air separation device selects gypsum and drying slag. The drying slag discharge end of the air separation device is connected to the feed end of the air separation slag hopper. The discharge ends of the air separation slag hopper, the clay hopper and the bentonite hopper are all connected to the feed end of the first stirring and mixing device. The discharge end of the first stirring and mixing device is connected to the feed end of the brick press. The raw ceramic bricks produced by the brick press are transported to the tunnel kiln for firing. The waste gas of the tunnel kiln is treated by the waste gas treatment device and then discharged into the atmosphere.

3. A lithium mica smelting slag resource system according to claim 1 or 2, characterized in that: The bricklaying production system includes a ball mill slag hopper, a slag hopper, a fly ash hopper, a drying equipment, a vertical grinding mill, an activator bin, a second stirring and mixing device and a bricklaying machine. The discharge end of the slag hopper is connected to the feed end of the drying equipment, the discharge ends of the drying equipment, the ball mill slag hopper and the fly ash hopper are all connected to the feed end of the vertical grinding mill, the discharge end of the vertical grinding mill, the discharge end of the air-selected gypsum of the air-selecting equipment and the discharge end of the activator bin are all connected to the feed end of the second stirring and mixing device, and the discharge end of the second stirring and mixing device is connected to the feed end of the bricklaying machine.

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