System for preparing industrial-grade lithium carbonate by using heterocyclic aramid fiber production waste liquid
By designing a system containing multiple treatment equipment, the lithium resources in the heterocyclic aramid production waste liquid are converted into industrial-grade lithium carbonate, which solves the problems of resource waste and environmental pollution, and realizes the recycling and industrialization of high-purity lithium application.
Patent Information
- Application Number
- CN202323621336.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-27
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2033-12-27
AI Technical Summary
The waste liquid produced during the production of heterocyclic aramid contains valuable lithium resources, which are difficult to separate and recycle, resulting in waste of resources and environmental pollution.
A system was designed, including plate heat exchanger, crystallization kettle, centrifuge, filter, leaching kettle, lithium sedimentation kettle, dryer and other equipment, and the lithium resources in the waste liquid were converted into industrial grade through a series of processing steps. Lithium carbonate includes cooling and precipitation of lithium-containing solid mixed salts, solid-liquid separation, precipitation, washing and drying, and finally obtaining high-purity lithium carbonate.
It realizes effective recycling and purification of lithium resources, avoids resource waste and environmental pollution, and the products meet industrial standards, are simple in system and low in cost, and are suitable for industrial production.
Smart Images
Figure CN222324550U_ABST
Abstract
Description
Technical field:
[0001] The utility model relates to a system for preparing industrial-grade lithium carbonate, in particular to a system for preparing industrial-grade lithium carbonate by utilizing waste liquid from heterocyclic aramid production. Background technology:
[0002] Heterocyclic aramid is made of three monomers: PPDA, DAPBI and TPC in a solvent system DMA. c -LiCl is obtained by polycondensation. During the polymerization process, the solvent and the auxiliary agent do not participate in the reaction. Therefore, the DMA obtained after polymerization c The main component of the mixed solution is DMA c , LiCl, H2O, HCl, and a small amount of other impurities, including DMA c 40-50%, LiCl 1-3%, HCl 0.2-0.3%. Of these, 80% of DMA c After vacuum distillation, it can be recovered, and the remaining 20% DMA c The additives exist in the production waste liquid in the form of solid solutions. Due to the difficulty in separation, the direct discharge of organic solutions containing LiCl will cause serious pollution to the environment and waste of lithium resources.
[0003] At the same time, the rapid development of the new energy industry in recent years has driven the price of lithium resources to continue to rise. Therefore, it is of great significance to extract and utilize the valuable lithium resources in production waste liquid. Utility model content:
[0004] In order to solve the above problems, the purpose of the utility model is to provide a system for preparing industrial-grade lithium carbonate using waste liquid from heterocyclic aramid production.
[0005] The utility model is implemented by the following technical solutions:
[0006] A system for preparing industrial-grade lithium carbonate using waste liquid from heterocyclic aramid production, comprising a plate heat exchanger, a crystallization kettle, a first centrifuge, a leaching kettle, a filter, a leaching liquid storage tank, a lithium precipitation kettle, a sodium carbonate preparation tank, a second centrifuge, and a first dryer;
[0007] The liquid outlet of the waste liquid main pipe is connected to the heat medium inlet of the plate heat exchanger, the heat medium outlet of the plate heat exchanger is connected to the inlet of the crystallization kettle through a pipeline, the kettle liquid outlet of the crystallization kettle is connected to the inlet of the first centrifuge through a pipeline, the solid phase outlet and the outlet of the pure water source of the first centrifuge are both connected to the inlet of the leaching kettle, the liquid outlet of the leaching kettle is connected to the inlet of the filter through a pipeline, the produced water outlet of the filter is connected to the inlet of the leaching liquid storage tank through a pipeline, the outlet of the leaching liquid storage tank and the outlet of the sodium carbonate preparation tank are both connected to the inlet of the lithium precipitation kettle through a pipeline, the outlet of the lithium precipitation kettle is connected to the inlet of the second centrifuge, and the solid phase outlet of the second centrifuge is connected to the inlet of the first dryer.
[0008] Further, it also includes a washing kettle, a third centrifuge and a second dryer;
[0009] The outlet of the first dryer and the outlet of the boiling water source are both connected to the inlet of the washing kettle, the outlet of the washing kettle is connected to the inlet of the third centrifuge, and the solid phase outlet of the third centrifuge is connected to the inlet of the second dryer.
[0010] Advantages of the utility model:
[0011] The utility model can recover lithium resources in the waste liquid of heterocyclic aramid production in the form of lithium carbonate, avoiding waste of resources and environmental pollution, and the purity of the obtained lithium carbonate can reach the standard of industrial-grade lithium carbonate. The utility model has a simple system, good product quality, and low investment cost, and is suitable for industrial production applications. Description of the drawings:
[0012] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0013] Figure 1 Schematic diagram of system connection of this embodiment.
[0014] In the figure: plate heat exchanger 1, crystallization kettle 2, first centrifuge 3, leaching kettle 4, filter 5, leaching liquid storage tank 6, lithium precipitation kettle 7, sodium carbonate preparation tank 8, second centrifuge 9, first dryer 10, washing kettle 11, third centrifuge 12, second dryer 13, pure water source 14, boiling water source 15. Specific implementation method:
[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0016] Embodiment 1:
[0017] like Figure 1 A system for preparing industrial-grade lithium carbonate using waste liquid from heterocyclic aramid production is shown, comprising a plate heat exchanger 1, a crystallization kettle 2, a first centrifuge 3, an extraction kettle 4, a filter 5, an extraction liquid storage tank 6, a lithium precipitation kettle 7, a sodium carbonate preparation tank 8, a second centrifuge 9, and a first dryer 10; and also comprising a washing kettle 11, a third centrifuge 12, and a second dryer 13;
[0018] The liquid outlet of the waste liquid main pipe is connected to the heat medium inlet of the plate heat exchanger 1, and the heat medium outlet of the plate heat exchanger 1 is connected to the inlet of the crystallization kettle 2 through a pipeline, and the kettle liquid outlet of the crystallization kettle 2 is connected to the inlet of the first centrifuge 3 through a pipeline. The solid phase outlet of the first centrifuge 3 and the outlet of the pure water source 14 are both connected to the inlet of the leaching kettle 4, the liquid outlet of the leaching kettle 4 is connected to the inlet of the filter 5 through a pipeline, the water outlet of the filter 5 is connected to the inlet of the leaching liquid storage tank 6 through a pipeline, the outlet of the leaching liquid storage tank 6 and the outlet of the sodium carbonate preparation tank 8 are both connected to the inlet of the lithium precipitation kettle 7 through a pipeline, the outlet of the lithium precipitation kettle 7 is connected to the inlet of the second centrifuge 9, and the solid phase outlet of the second centrifuge 9 is connected to the inlet of the first dryer 10.
[0019] The outlet of the first dryer 10 and the outlet of the boiling water source 15 are both connected to the inlet of the washing kettle 11 , the outlet of the washing kettle 11 is connected to the inlet of the third centrifuge 12 , and the solid phase outlet of the third centrifuge 12 is connected to the inlet of the second dryer 13 .
[0020] Job Description:
[0021] The production waste liquid first enters the plate heat exchanger 1 through the waste liquid main pipe, exchanges heat with the circulating cooling water and cools down, and then enters the crystallization kettle 2, where the solid mixed salt containing lithium is precipitated by cooling, and then the solid-liquid separation is achieved by the first centrifuge 3 to obtain the solid phase solid mixed salt containing lithium and the liquid phase high-purity DMAc containing lithium. The high-purity DMAc containing lithium returns to the DMAc distillation kettle to participate in the distillation treatment again, and the solid mixed salt containing lithium enters the leaching kettle 4, where it is dissolved in pure water to form a lithium-containing stock solution with a DMAc concentration of 40-50% and a pH of 3-4; the lithium-containing stock solution is filtered out by the filter 5 to remove the lithium-containing solid mixed salt that is not fully dissolved in pure water. After the lithium-containing solid mixed salt in the water is filtered, it enters the leaching liquid storage tank 6 for temporary storage, and then enters the lithium precipitation kettle 7, and a certain amount of 24%-26% saturated sodium carbonate solution is added to obtain Li2CO3 precipitation; the solid phase Li2CO3 precipitation obtained by the second centrifuge 9 first enters the first dryer 10 for drying treatment, and then enters the washing kettle 11, and is washed 2-3 times with boiling water, and then after the liquid phase is removed by the third centrifuge 12, it is dried by the second dryer 13 at a temperature of 110-140°C, and dried for 1-2 hours to obtain industrial grade Li2CO3.
[0022] Li2CO3, as an important lithium product, can be processed into other lithium products and has a wide range of applications. Its current main use is in the preparation of lithium battery materials, including new energy vehicle power batteries, consumer electronics batteries, and energy storage batteries. Other application areas include traditional industries such as glass ceramics, medicine, and grease.
[0023] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A system for preparing industrial-grade lithium carbonate using waste liquid from heterocyclic aramid production, characterized in that: It includes a plate heat exchanger, a crystallization kettle, a first centrifuge, an leaching kettle, a filter, an leaching liquid storage tank, a lithium precipitation kettle, a sodium carbonate preparation tank, a second centrifuge, and a first dryer; The liquid outlet of the waste liquid main pipe is connected to the heat medium inlet of the plate heat exchanger, the heat medium outlet of the plate heat exchanger is connected to the inlet of the crystallization kettle through a pipeline, the kettle liquid outlet of the crystallization kettle is connected to the inlet of the first centrifuge through a pipeline, the solid phase outlet and the outlet of the pure water source of the first centrifuge are both connected to the inlet of the leaching kettle, the liquid outlet of the leaching kettle is connected to the inlet of the filter through a pipeline, the produced water outlet of the filter is connected to the inlet of the leaching liquid storage tank through a pipeline, the outlet of the leaching liquid storage tank and the outlet of the sodium carbonate preparation tank are both connected to the inlet of the lithium precipitation kettle through a pipeline, the outlet of the lithium precipitation kettle is connected to the inlet of the second centrifuge, and the solid phase outlet of the second centrifuge is connected to the inlet of the first dryer.
2. A system for preparing industrial-grade lithium carbonate using waste liquid from heterocyclic aramid production according to claim 1, characterized in that: Also includes a washing kettle, a third centrifuge and a second dryer; The outlet of the first dryer and the outlet of the boiling water source are both connected to the inlet of the washing kettle, the outlet of the washing kettle is connected to the inlet of the third centrifuge, and the solid phase outlet of the third centrifuge is connected to the inlet of the second dryer.