System for improving lithium recovery rate

Abstract

The utility model relates to a system for improving the lithium recovery rate. The system comprises a pulping device (1), a purification and separation device (2), a causticizing device (3) and a slag washing device (4), the pulping device (1) is respectively connected with an ore sample conveying device and a calcium carbonate conveying device from the outside of the system, and an outlet of the pulping device (1) is connected with the purification and separation device (2); a causticized liquid discharge port in the causticizing device (3) is connected into the purification and separation device (2), and a causticized raw slag discharge port is connected with the slag washing device (4); a washing water outlet in the slag washing device (4) is connected to the causticizing device (3), and a causticized slag outlet is connected to the pulping device (1). According to the system, lithium intermediate products can be subjected to causticization recovery, the causticization liquid return system directly utilizes lithium resources, causticization residues return to the pulping device on one hand to replace part of calcium carbonate to back adjust the pulping acidity, on the other hand, the residual lithium resources in the causticization residues are recovered, and the overall recovery rate of the lithium resources can be increased.

Description

Technical Field

[0001] This utility model relates to the field of lithium salt production technology, specifically a system for improving lithium recovery rate. Background Technology

[0002] With the booming development of the power battery and energy storage sectors, the demand for battery-grade lithium carbonate has remained high in recent years. Generally, lithium carbonate producers will try to convert lithium resources in lithium mines into battery-grade lithium carbonate to the greatest extent possible, which involves the development and utilization of trace lithium resources.

[0003] Currently, there are patents (CN 119524472 A) for recovering trace lithium resources from sodium sulfate produced in the sulfuric acid process lithium salt production system. Specifically, lithium is recovered through sodium sulfate dissolution and adsorption, and this method can recover more than 90% of the lithium resources in sodium sulfate. Patent (CN 216459396 U) comprehensively recovers lithium, iron, gypsum, aluminum, tantalum, and niobium resources by treating lithium slag through a series of complex mineral processing methods, pioneering the maximization of lithium slag resource utilization. Both of these patents use complex processes and large-scale equipment to process and recover lithium resources from byproducts generated during lithium salt production, achieving good lithium recovery results, but requiring large industrial investments and difficult to put into production. Patent (CN 114105172 A) uses lime causticization to further produce battery-grade lithium carbonate from crude lithium carbonate produced during lithium salt production, but the residual lithium in the causticization slag is not utilized, indicating room for further improvement in lithium yield.

[0004] Therefore, we still need to conduct further research and development on lithium recycling to improve the overall lithium recovery rate. Utility Model Content

[0005] To address the problems mentioned in the background art, this utility model proposes a system for improving lithium recovery rate. This system can causticize and recover lithium intermediate products, and the causticizing liquid is returned to the system to directly utilize lithium resources. The causticizing residue is returned to the pulping device to replace part of the calcium carbonate used to adjust the pulp acidity, and to recover the residual lithium resources in the causticizing residue, thereby improving the overall lithium resource recovery rate.

[0006] To achieve the above-mentioned objectives, the specific technical solution of this utility model is as follows:

[0007] A system for improving lithium recovery rate, the system comprising: a pulping unit, a purification and separation unit, a causticizing unit, and a slag washing unit;

[0008] The pulping device is connected to a mineral sample conveying device and a calcium carbonate conveying device from outside the system, respectively, and the outlet of the pulping device is connected to a purification and separation device.

[0009] The purification and separation device is equipped with a slag discharge port, a finished lithium carbonate discharge port, and a crude lithium carbonate discharge port. The crude lithium carbonate discharge port is connected to the causticizing device.

[0010] The causticizing device contains lime slurry and is connected to a purification and separation device and a slag washing device, respectively.

[0011] The slag washing device is connected to the pulping device.

[0012] Furthermore, in the aforementioned system for improving lithium recovery rate, the slurry preparation device includes a mineral sample metering device, a calcium carbonate metering device, a stirring device, and a slurry conveying device; both the mineral sample metering device and the calcium carbonate metering device are connected to the stirring device; a discharge port is provided at the lower part of the stirring device, which is connected to the slurry conveying device; the slurry conveying device is connected to a purification and separation device.

[0013] Furthermore, the mineral sample metering device and the calcium carbonate metering device are respectively connected to the mineral sample conveying device and the calcium carbonate conveying device outside the system. Both are metered and then conveyed into the pulping device.

[0014] The pulping device mixes the mineral sample with calcium carbonate (including caustic slag) evenly to consume the residual acid in the mineral sample.

[0015] Furthermore, in the aforementioned system for improving lithium recovery rate, the purification and separation device includes a filtration system, an impurity removal system, a carbonization system, and a centrifugation system; the filtration system is connected to a slurry conveying device, and the filtration system is provided with a drain port, which is connected to the impurity removal system; the impurity removal system is connected to the carbonization system; the carbonization system is connected to the centrifugation system; and the centrifugation system is provided with a crude lithium carbonate discharge port.

[0016] Furthermore, the filtration system is also equipped with a slag discharge port, which is connected to the outside of the system.

[0017] The purification and separation device performs impurity purification, evaporation and concentration, lithium salt synthesis, solid-liquid separation and other processes on the slurry, and finally produces external slag, battery-grade lithium carbonate and crude lithium carbonate.

[0018] Furthermore, in the aforementioned system for improving lithium recovery rate, the causticizing device includes a lime slurry preparation system, a causticizing reaction system, and a causticizing device solid-liquid separation system; the lime slurry preparation system is connected to the causticizing reaction system, and the causticizing reaction system is connected to the causticizing device solid-liquid separation system.

[0019] The causticization reaction system is connected to the crude lithium carbonate discharge port on the centrifugal system.

[0020] The solid-liquid separation system of the causticizing device is equipped with a causticizing liquid outlet and a causticizing raw residue outlet; wherein the causticizing liquid outlet is connected to the purification and separation device, and the causticizing raw residue outlet is connected to the residue washing device.

[0021] The causticizing unit reacts crude lithium carbonate with lime slurry to produce causticizing liquid and causticizing residue. The causticizing liquid is a lithium hydroxide solution containing impurity elements and is connected to a purification and separation unit. The causticizing residue is calcium carbonate containing lithium and is connected to a pulping unit.

[0022] Furthermore, in the aforementioned system for improving lithium recovery rate, the slag washing device includes a washing system and a solid-liquid separation system for the slag washing device; the washing system is connected to the causticization raw slag discharge port provided on the causticization reaction system and then connected to the solid-liquid separation system for the slag washing device.

[0023] The solid-liquid separation system of the slag washing device is equipped with a caustic slag outlet and a wash water outlet. The caustic slag outlet is connected to a calcium carbonate metering device, and the wash water outlet is connected to a lime slurry preparation system.

[0024] The slag washing unit washes the soluble lithium in the causticized raw slag, and the resulting wash water is a low-concentration lithium hydroxide solution, which is returned to the lime slurry in the causticizing unit. The main component of the produced causticized slag is calcium carbonate, which is returned to the pulping unit for recycling.

[0025] Because the causticized raw residue contains causticized lithium hydroxide solution and unreacted crude lithium carbonate, it needs to be washed to reduce the lithium content before it can be used for pulping.

[0026] The causticizing slag can replace part of the calcium carbonate in the pulping device, and after being mixed with the mineral sample for pulping, the residual lithium resources in the causticizing slag can be further recovered.

[0027] Compared with the prior art, the beneficial effects of this utility model are reflected in:

[0028] (1) Through this system, the causticized residue obtained after causticizing crude lithium carbonate lime slurry is further washed and the lithium resources therein are recovered. This part of the lithium resources can be directly entered into the causticized liquid and thus returned to the main system for generating battery-grade lithium carbonate, reducing the idle circulation of this part of the lithium resources.

[0029] (2) Through this system, the washed caustic slag is returned to the pulping device, which can replace part of the calcium carbonate to neutralize the residual acid in the mineral sample, saving auxiliary material consumption. In addition, the lithium resources remaining in the caustic slag can be redissolved and enter the purification and separation system during the pulping process, further improving the lithium recovery rate. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a diagram illustrating the system configuration for improving lithium recovery rate according to the present invention.

[0032] The components include: 1. Pulping device; 2. Purification and separation device; 3. Causticizing device; 4. Slag washing device; 5. Mineral sample metering device; 6. Mineral sample conveying device; 7. Calcium carbonate metering device; 8. Calcium carbonate conveying device; 9. Slag discharge port; 10. Crude lithium carbonate discharge port; 11. Finished lithium carbonate discharge port. Detailed Implementation

[0033] The exemplary embodiments will now be described in more full detail. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more complete and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0034] Furthermore, the described features or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application may be practiced without one or more of the specific details, or other methods, steps, etc. may be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0035] The embodiments are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the actual situation.

[0036] It should be noted that "multiple" in this article refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0037] It should be noted that the order in which the methods are mentioned in the specification and claims of this application should be understood to be interchangeable where appropriate, so that the embodiments of this application described herein can be implemented in a different order than those described.

[0038] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of the embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0039] Example 1

[0040] This utility model embodiment relates to a system for improving lithium recovery rate, and the connection relationships of the various structures in the system are as follows: Figure 1 As shown, the system includes: a pulping device 1, a purification and separation device 2, a causticizing device 3, and a slag washing device 4;

[0041] The pulping device is connected to a mineral sample conveying device and a calcium carbonate conveying device from outside the system, respectively, and the outlet of the pulping device is connected to a purification and separation device.

[0042] The purification and separation device is equipped with a slag discharge port 9, a finished lithium carbonate discharge port 11 and a crude lithium carbonate discharge port 10. The crude lithium carbonate discharge port is connected to the causticizing device.

[0043] The causticizing device contains lime slurry and is connected to a purification and separation device and a slag washing device, respectively.

[0044] The slag washing device is connected to the pulping device.

[0045] More specifically, the pulping device 1 includes a mineral sample metering device 5, a calcium carbonate metering device 7, a stirring device, and a slurry conveying device; both the mineral sample metering device 5 and the calcium carbonate metering device 7 are connected to the stirring device; a discharge port is provided at the bottom of the stirring device, which is connected to the slurry conveying device; the slurry conveying device is connected to the purification and separation device 2.

[0046] Furthermore, the mineral sample metering device 5 and the calcium carbonate metering device 7 are respectively connected to the mineral sample conveying device 6 and the calcium carbonate conveying device 8 outside the system; both are conveyed through the conveying device after metering and enter the pulping device.

[0047] The pulping device mixes the mineral sample with calcium carbonate (including caustic slag) evenly to consume the residual acid in the mineral sample.

[0048] The purification and separation device 2 includes a filtration system, a purification system, a carbonization system, and a centrifugation system. The filtration system is connected to the slurry conveying device of the pulping device 1. The filtration system is provided with a drain port, which is connected to the purification system. The purification system is connected to the carbonization system. The carbonization system is connected to the centrifugation system. The centrifugation system is provided with a crude lithium carbonate discharge port.

[0049] Furthermore, the filtration system is also equipped with a slag discharge port, which is connected to the outside of the system.

[0050] The purification and separation device performs impurity purification, evaporation and concentration, lithium salt synthesis, solid-liquid separation and other processes on the slurry, and finally produces external slag, battery-grade lithium carbonate and crude lithium carbonate.

[0051] The causticizing device 3 includes a lime slurry preparation system, a causticizing reaction system, and a causticizing device solid-liquid separation system; the lime slurry preparation system is connected to the causticizing reaction system, and the causticizing reaction system is connected to the causticizing device solid-liquid separation system.

[0052] The causticization reaction system is connected to the crude lithium carbonate discharge port on the centrifugal system.

[0053] The solid-liquid separation system of the causticizing device is equipped with a causticizing liquid outlet and a causticizing raw residue outlet; wherein the causticizing liquid outlet is connected to the purification and separation device, and the causticizing raw residue outlet is connected to the residue washing device.

[0054] The causticizing unit 3 reacts crude lithium carbonate with lime slurry to produce causticizing liquid and causticizing residue. The causticizing liquid is a lithium hydroxide solution containing impurity elements and is connected to a purification and separation unit. The causticizing residue is calcium carbonate containing lithium and is connected to a pulping unit.

[0055] The slag washing device 4 includes a washing system and a solid-liquid separation system. The washing system is connected to the causticization raw slag discharge port on the causticization reaction system and then to the solid-liquid separation system. The solid-liquid separation system is equipped with a causticization slag discharge port and a wash water discharge port. The causticization slag discharge port is connected to the calcium carbonate metering device 7 of the pulping device 1, and the wash water discharge port is connected to the lime pulping system of the causticization device 3.

[0056] The slag washing unit washes the soluble lithium in the causticized raw slag, and the resulting wash water is a low-concentration lithium hydroxide solution, which is returned to the lime slurry in the causticizing unit. The main component of the produced causticized slag is calcium carbonate, which is returned to the pulping unit for recycling.

[0057] Because the causticized raw residue contains causticized lithium hydroxide solution and unreacted crude lithium carbonate, it needs to be washed to reduce the lithium content before it can be used for pulping.

[0058] The causticizing slag can replace part of the calcium carbonate in the pulping device, and after being mixed with the mineral sample for pulping, the residual lithium resources in the causticizing slag can be further recovered.

[0059] This embodiment can maximize the recovery of lithium resources in the system and save some calcium carbonate auxiliary materials.

[0060] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

[0061] The background section is provided to generally present the context of this utility model. The work of the currently named inventors, the work to the extent described in this background section, and aspects described in this section that did not constitute prior art at the time of filing are neither expressly nor impliedly acknowledged as prior art to this utility model.

Claims

1. A system for improving lithium recovery rate, characterized in that, The system includes: a pulping unit (1), a purification and separation unit (2), a causticizing unit (3), and a slag washing unit (4); The pulping device (1) is connected to the mineral sample conveying device (6) and the calcium carbonate conveying device (8) respectively, and the outlet of the pulping device (1) is connected to the purification and separation device (2). The purification and separation device (2) is provided with a slag discharge port (9), a finished lithium carbonate discharge port (11) and a crude lithium carbonate discharge port (10), and the crude lithium carbonate discharge port (10) is connected to the causticizing device (3). The causticizing device (3) contains lime slurry and is connected to the purification and separation device (2) and the slag washing device (4) respectively. The slag washing device (4) is connected to the pulping device (1).

2. The system for improving lithium recovery rate according to claim 1, characterized in that, The pulping device (1) includes a mineral sample metering device (5), a calcium carbonate metering device (7), a stirring device, and a slurry conveying device; the mineral sample metering device (5) and the calcium carbonate metering device (7) are both connected to the stirring device; the stirring device is provided with a discharge port at the bottom, which is connected to the slurry conveying device; the slurry conveying device is connected to the purification and separation device (2).

3. A system for improving lithium recovery rate according to claim 1 or 2, characterized in that, The purification and separation device (2) includes a filtration system, a slurry removal system, a carbonization system, and a centrifugation system; wherein the filtration system is connected to the slurry conveying device, and the filtration system is provided with a drain port, which is connected to the slurry removal system; the slurry removal system is connected to the carbonization system; the carbonization system is connected to the centrifugation system; and the centrifugation system is provided with a crude lithium carbonate drain port.

4. The system for improving lithium recovery rate according to claim 2, characterized in that, The mineral sample metering device (5) and the calcium carbonate metering device (7) are respectively connected to the mineral sample conveying device (6) and the calcium carbonate conveying device (8).

5. The system for improving lithium recovery rate according to claim 3, characterized in that, The causticizing device (3) includes a lime slurry preparation system, a causticizing reaction system, and a causticizing device solid-liquid separation system; the lime slurry preparation system is connected to the causticizing reaction system, and the causticizing reaction system is connected to the causticizing device solid-liquid separation system.

6. A system for improving lithium recovery rate according to claim 1 or 5, characterized in that, The slag washing device (4) includes a washing system and a slag washing device solid-liquid separation system; the washing system is connected to the caustic raw slag discharge port provided on the caustic reaction system and then connected to the slag washing device solid-liquid separation system.

7. The system for improving lithium recovery rate according to claim 3, characterized in that, The filtration system is also equipped with a slag discharge port, which is connected to the outside of the system.

8. The system for improving lithium recovery rate according to claim 5, characterized in that: The causticization reaction system is connected to the crude lithium carbonate discharge port on the centrifugal system.

9. A system for improving lithium recovery rate according to claim 5, characterized in that, The solid-liquid separation system of the causticizing device is provided with a causticizing liquid outlet and a causticizing raw slag outlet, wherein the causticizing liquid outlet is connected to the purification and separation device (2), and the causticizing raw slag outlet is connected to the slag washing device (4).

10. A system for improving lithium recovery rate according to claim 6, characterized in that, The solid-liquid separation system of the slag washing device is equipped with a caustic slag outlet and a washing water outlet. The caustic slag outlet is connected to the calcium carbonate metering device (7), and the washing water outlet is connected to the lime slurry preparation system.

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