A process and device for recycling unqualified materials in lithium carbonate production

Abstract

This invention discloses a process and apparatus for recycling substandard materials in lithium carbonate production. The recycling process includes the following steps: injecting demineralized water at a certain temperature into a recycling slurry tank; filtering the substandard lithium carbonate material and then adding it to the recycling slurry tank for demagnetization under stirring conditions to prepare a lithium carbonate slurry; conveying the lithium carbonate slurry to a filter for filtration; detecting the physical parameters of the filtered lithium carbonate slurry and determining whether the physical parameters meet the process specifications; conveying the lithium carbonate slurry that meets the process specifications to a thickener; and discharging the lithium carbonate slurry that does not meet the process specifications into a waste collection tank. Based on this, an apparatus for recycling substandard lithium carbonate materials is also proposed. This invention achieves resource recycling by recycling substandard materials in lithium carbonate production through a recycling apparatus.

Description

Technical Field

[0001] This invention belongs to the field of lithium carbonate production technology, specifically relating to a process and apparatus for recycling substandard materials in lithium carbonate production. Background Technology

[0002] In the lithium extraction process from salt lakes, processes such as lithium precipitation, drying, packaging, and material conveying generate a certain amount of lithium-containing powder or substandard materials. Specifically, the bag filter dust collector in the dryer of the lithium precipitation process collects a large amount of fine lithium carbonate powder, and the dust collector in the packaging process also recovers some lithium carbonate powder. Additionally, material spillage is inevitable during the operation of the conveyor belts in the lithium carbonate production line, and the packaging iron separator generates discharge containing magnetic impurities. Furthermore, during planned equipment maintenance or unplanned shutdowns, lithium carbonate material containing impurities but of acceptable quality will also be generated and requires cleaning.

[0003] Currently, there is a lack of effective online recycling methods for lithium carbonate materials or recycled powder generated in the above-mentioned stages. The conventional practice is to collect and package them manually and then store them in designated areas of the plant. This storage directly wastes lithium carbonate resources; moreover, the large-scale storage of powder also occupies plant land resources, increases warehouse management costs, and further leads to waste of lithium carbonate materials and loss of economic benefits. Summary of the Invention

[0004] The purpose of this invention is to provide a process and apparatus for recycling substandard materials in lithium carbonate production, thereby achieving resource recycling.

[0005] To achieve the above objectives, this invention proposes a process for recycling substandard materials in lithium carbonate production, comprising the following steps:

[0006] Step 1: Inject demineralized water at a certain temperature into the slurry recovery tank;

[0007] Step 2: After filtering the substandard lithium carbonate material, put it into the recycling slurry tank and demagnetize it under stirring conditions to prepare lithium carbonate slurry;

[0008] Step 3: The lithium carbonate slurry is fed to a filter for filtration;

[0009] Step 4: Detect the physical parameters of the lithium carbonate slurry after filtration by the filter, and determine whether the physical parameters meet the process specifications;

[0010] Step 5: Transport the lithium carbonate slurry that meets the process specifications to the thickener;

[0011] Step 6: Discharge the lithium carbonate slurry that does not meet the process specifications into the waste collection tank.

[0012] Preferably, in step one, the temperature of the demineralized water is 75-85℃.

[0013] Preferably, in step two, stirring is performed when the liquid level in the recycled slurry tank reaches 50%-70%.

[0014] Preferably, in step two, the unqualified lithium carbonate material includes at least one of the following: lithium carbonate powder collected by the bag filter of the dryer in the lithium precipitation process, lithium carbonate powder generated by the packaging dust collector, lithium carbonate powder leaked from the conveyor belt of the lithium carbonate production line, material discharged from the packaging iron remover, and clean lithium carbonate material cleaned up during equipment maintenance.

[0015] Preferably, in step four, the physical parameters include impurity content and lithium carbonate slurry density.

[0016] On the other hand, the present invention also proposes a recycling device for the above-mentioned lithium carbonate substandard material recycling process, comprising: a base, a recycling slurry tank, a filter and a return pump, wherein the recycling slurry tank, the filter and the return pump are all fixed on the base;

[0017] The recovery slurry tank is used to hold demineralized water and substandard lithium carbonate. The recovery slurry tank is equipped with a stirrer and a demagnetizer. The filter is connected to the outlet of the recovery slurry tank and is used to filter the lithium carbonate slurry. The return pump is connected downstream of the filter and is used to transport the filtered lithium carbonate slurry to the thickener.

[0018] Preferably, a sampling branch is provided on the pipeline between the filter and the return pump, and a sampling valve is provided on the sampling branch.

[0019] Preferably, the recycling device further includes: a waste collection tank, a switching valve is provided on the pipeline between the filter and the return pump, the first outlet of the switching valve is connected to the thickener, and the second outlet of the switching valve is connected to the waste collection tank.

[0020] Preferably, the top of the recycled slurry tank is provided with a hopper, the outlet of which is connected to the inlet of the recycled slurry tank; a filter screen is provided inside the hopper.

[0021] Preferably, two return pumps are arranged in parallel.

[0022] Preferably, the base has a moving mechanism at its bottom.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention utilizes a recycling device to process substandard lithium carbonate materials using a wet process, optimizing the workshop's operating environment and ensuring the purity of the recycled materials. This allows previously difficult-to-process substandard lithium carbonate materials to return to the production process, achieving resource recycling.

[0025] The recycling device of this invention has a compact structure, effectively saving space on the production site. The operation process is simple and convenient, allowing operators to quickly learn how to use it, and its location can be flexibly adjusted according to the operational needs of different production areas. Its modular design also facilitates later maintenance, significantly reducing equipment operation and maintenance time costs. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the lithium carbonate substandard material recycling device connected to the thickener in this invention.

[0027] In the diagram: 1. Base; 11. Roller; 2. Recycle slurry tank; 21. Demagnetizer; 3. Agitator; 4. Feed hopper; 41. Filter screen; 5. Filter; 6. Return pump; 7. Thickener; 8. Finished product dust collector. Detailed Implementation

[0028] The invention will now be further described with reference to the accompanying drawings.

[0029] A process for recycling substandard materials in lithium carbonate production includes the following steps:

[0030] Step 1: Inject demineralized water at a certain temperature into the slurry recovery tank; the temperature of the demineralized water is 75-85℃, preferably 80℃.

[0031] Step Two: After filtering the substandard lithium carbonate material, it is placed into a recycling slurry tank for demagnetization under stirring conditions to prepare a lithium carbonate slurry. The substandard lithium carbonate material includes at least one of the following: lithium carbonate powder collected by the bag filter of the dryer in the lithium precipitation process, lithium carbonate powder generated by the packaging dust collector, lithium carbonate powder leaked from the conveyor belt of the lithium carbonate production line, discharge material from the packaging iron separator, and clean lithium carbonate material cleaned during equipment maintenance. Filtering the substandard lithium carbonate material and placing it into the recycling slurry tank provides preliminary filtration. After being placed in the recycling slurry tank, the stirrer is activated to agitate the substandard lithium carbonate material, simultaneously removing magnetic materials, which generally include iron-containing metal particles.

[0032] Stirring should be carried out when the liquid level in the recovery slurry tank reaches 50%-70%, preferably 60%. Stirring at this liquid level can quickly disperse the substandard lithium carbonate material, form a uniform slurry, and prevent agglomeration.

[0033] The temperature of the demineralized water in the slurry recovery tank is 80℃. The solubility of lithium carbonate in water decreases as the temperature increases. At 80℃, the solubility of lithium carbonate is only 0.85 g / L, approximately 64% of the 1.33 g / L at room temperature (20℃). This indicates that, with the same amount of water, more substandard lithium carbonate will be suspended in the water as solid particles, forming a high-concentration slurry. The solid content of this high-concentration slurry can match the process requirements of subsequent processes (such as thickeners and centrifuges), enabling smooth material return.

[0034] Although lithium carbonate is difficult to dissolve in the recycling slurry tank, the desalination water at 80°C can reduce the viscosity of the slurry, which helps the lithium carbonate to be better wetted and dispersed in water, avoids clumping, and forms a uniform, pumpable suspension slurry that is easy to transport through pipelines.

[0035] Step 3: The lithium carbonate slurry is fed to a filter for filtration; this is used to filter out impurities in the slurry. Impurities that can be filtered out are generally insoluble impurities, such as soil, plastic fragments, screws, etc.

[0036] Step 4: Detect the physical parameters of the lithium carbonate slurry after filtration and determine whether they meet the process specifications. The main physical parameters of the lithium carbonate slurry include impurity content and density. Impurities mainly include hydrochloric acid insolubles and magnetic substances. The hydrochloric acid insoluble content should be ≤0.005%, and the magnetic substance content should be ≤0.00002%. The lithium carbonate slurry density should be 1150–1300 kg / m³. 3 .

[0037] Soluble impurities that dissolve in desalinated water are further removed by the thickener process after the lithium carbonate slurry enters the production process. The thickener will perform thickening, washing, and purification steps on the lithium carbonate slurry. Therefore, there is no need to limit the content of soluble impurities in the recycling process of substandard materials in lithium carbonate production.

[0038] Step 5: The lithium carbonate slurry that meets the process specifications is transported to a thickener to combine the lithium carbonate slurry with the slurry from the lithium carbonate extraction production line.

[0039] Step 6: Return the lithium carbonate slurry that does not meet the process specifications to the waste collection tank and store it.

[0040] Preferably, the unqualified lithium carbonate material includes at least one of the following: lithium carbonate powder collected by the bag filter of the dryer in the lithium precipitation process, lithium carbonate powder generated by the packaging dust collector, lithium carbonate powder leaked from the conveyor belt of the lithium carbonate production line, material discharged from the packaging iron separator, and clean lithium carbonate material cleaned up during equipment maintenance.

[0041] The lithium carbonate powder collected by the bag filter dust collector in the lithium precipitation process dryer, the lithium carbonate powder generated by the packaging dust collector, the lithium carbonate powder leaked from the conveyor belt of the lithium carbonate production line, the discharge material from the packaging iron separator, and the clean lithium carbonate material cleaned during equipment maintenance are generally collected manually and then stockpiled, resulting in waste of substandard lithium carbonate and loss of economic benefits. The lithium carbonate powder collected by the bag filter dust collector in the lithium precipitation process dryer, the lithium carbonate powder generated by the packaging dust collector, the lithium carbonate powder leaked from the conveyor belt of the lithium carbonate production line, the discharge material from the packaging iron separator, and the clean lithium carbonate material cleaned during equipment maintenance should be put into a recovery slurry tank, mixed with 70°C demineralized water to form a lithium carbonate slurry. The lithium carbonate slurry that meets the process specifications should then be transported to the thickener and reintroduced into the main production line.

[0042] like Figure 1 As shown, the present invention also proposes a recycling device for the recycling process of substandard lithium carbonate materials, comprising: a base 1, a recycling slurry tank 2, a filter 5, and a return pump 6, wherein the recycling slurry tank 2, the filter 5, and the return pump 6 are all fixed on the base 1. The bottom of the base 1 is provided with a moving mechanism, which may include rollers 11 or a skid mount.

[0043] The recovery slurry tank 2 is used to hold demineralized water and substandard lithium carbonate. The recovery slurry tank 2 is equipped with an agitator 3 and a demagnetizer 21. Specifically, the agitator 3 includes an agitator rod and an agitator paddle. The agitator 3 is fixed to the outside of the recovery slurry tank 2 by the agitator rod, and the agitator paddle extends into the recovery slurry tank 2. The demagnetizer 21 is located on the inner wall of the recovery slurry tank 2. The filter 5 is connected to the outlet of the recovery slurry tank 2 to further filter large particulate impurities in the lithium carbonate slurry. The return pump 6 is connected downstream of the filter 5 to transport the filtered lithium carbonate slurry to the thickener 7.

[0044] Preferably, a sampling branch is provided on the pipeline between the filter 5 and the return pump 6, and a sampling valve is provided on the sampling branch. By opening the sampling valve, lithium carbonate slurry can be obtained, thereby detecting the physical parameters of the lithium carbonate slurry.

[0045] Preferably, the recycling device further includes: a waste collection tank; a switching valve is installed on the pipeline between the filter 5 and the return pump 6; the first outlet of the switching valve is connected to the thickener 7; and the second outlet of the switching valve is connected to the waste collection tank. After the physical parameters of the lithium carbonate slurry are tested, if the physical parameters of the lithium carbonate slurry meet the process specifications, it enters the thickener 7 through the first outlet of the switching valve; if the physical parameters of the lithium carbonate slurry do not meet the process specifications, it enters the waste collection tank through the second outlet of the switching valve for storage of lithium carbonate slurry that still does not meet the process specifications after being processed by the recycling device.

[0046] Preferably, the top of the recycling slurry tank 2 is provided with a hopper 4, and the outlet of the hopper 4 is connected to the inlet of the recycling slurry tank 2; a filter screen 41 is provided inside the hopper 4. The hopper 4 facilitates the feeding of substandard lithium carbonate, and the filter screen 41 inside the hopper 4 can perform preliminary filtration of impurities in the substandard lithium carbonate.

[0047] Preferably, a finished product dust collector 8 is provided above the feeding hopper 4. When unqualified lithium carbonate material is fed into the feeding hopper 4 by a forklift, a dust-laden airflow is generated in the feeding hopper 4; the finished product dust collector 8 draws the dust-laden airflow into the finished product dust collector 8 through its suction port, filters the dust through the filter element, and discharges the purified gas into the atmosphere, while collecting the intercepted lithium carbonate dust in the dust collection box of the finished product dust collector 8, which is cleaned and recycled regularly.

[0048] Preferably, two return pumps 6 are arranged in parallel, one in operation and one on standby, to transport lithium carbonate slurry that meets the process specifications to the thickener 7.

[0049] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A process for recycling substandard materials in lithium carbonate production, characterized in that, Includes the following steps: Step 1: Inject demineralized water at a certain temperature into the slurry recovery tank; Step 2: After filtering the substandard lithium carbonate material, put it into the recycling slurry tank and demagnetize it under stirring conditions to prepare lithium carbonate slurry; Step 3: The lithium carbonate slurry is fed to a filter for filtration; Step 4: Detect the physical parameters of the lithium carbonate slurry after filtration by the filter, and determine whether the physical parameters meet the process specifications; Step 5: Transport the lithium carbonate slurry that meets the process specifications to the thickener; Step 6: Discharge the lithium carbonate slurry that does not meet the process specifications into the waste collection tank.

2. The recycling process for substandard materials in lithium carbonate production according to claim 1, characterized in that, In step one, the temperature of the demineralized water is 75-85℃.

3. The recycling process for substandard materials in lithium carbonate production according to claim 1, characterized in that, In step two, stirring is performed when the liquid level in the recycled slurry tank reaches 50%-70%.

4. The process for recycling substandard materials in lithium carbonate production according to claim 1, characterized in that, In step two, the substandard lithium carbonate material includes at least one of the following: lithium carbonate powder collected by the bag filter of the dryer in the lithium precipitation process, lithium carbonate powder generated by the packaging dust collector, lithium carbonate powder leaked from the conveyor belt of the lithium carbonate production line, material discharged from the packaging iron remover, and clean lithium carbonate material cleaned up during equipment maintenance.

5. The process for recycling substandard materials in lithium carbonate production according to claim 1, characterized in that, In step four, the physical parameters include impurity content and lithium carbonate slurry density.

6. A recycling apparatus for the process of recovering substandard materials in lithium carbonate production according to any one of claims 1-5, characterized in that, include: The base (1), the slurry recovery tank (2), the filter (5) and the return pump (6) are all fixed on the base (1); The recovery slurry tank (2) is used to hold demineralized water and unqualified lithium carbonate material. The recovery slurry tank (2) is equipped with a stirrer (3) and a demagnetizer (21). The filter (5) is connected to the outlet of the recovery slurry tank (2) and is used to filter the lithium carbonate slurry. The return pump (6) is connected downstream of the filter (5) and is used to transport the filtered lithium carbonate slurry to the thickener (7).

7. The device for recycling substandard materials in lithium carbonate production according to claim 6, characterized in that, A sampling branch is provided on the pipeline between the filter (5) and the return pump (6), and a sampling valve is provided on the sampling branch.

8. The device for recycling substandard materials in lithium carbonate production according to claim 7, characterized in that, Also includes: A switching valve is installed on the pipeline between the filter (5) and the return pump (6) in the waste collection tank. The first outlet of the switching valve is connected to the thickener (7), and the second outlet of the switching valve is connected to the waste collection tank.

9. The device for recycling substandard materials in lithium carbonate production according to claim 6, characterized in that, The top of the recycling slurry tank (2) is provided with a feeding hopper (4), and the outlet of the feeding hopper (4) is connected to the inlet of the recycling slurry tank (2); a filter screen (41) is provided inside the feeding hopper (4).

10. The device for recycling substandard materials in lithium carbonate production according to claim 6, characterized in that, The base (1) is provided with a moving mechanism at its bottom.

Images