System for preparing high-purity potassium sulfate from lithium precipitation mother liquor
By designing a system containing decarbonization and evaporation equipment and potassium Glauber's freezing crystal kettle, separating and reacting potassium Glauber's salt and potassium chloride, the problem of difficulty in recovering lithium ions and preparing high-purity potassium sulfate in the prior art is solved, and high-efficiency lithium Resource utilization and high-purity potassium sulfate production.
Patent Information
- Application Number
- CN202420277469.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-05
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-02-05
AI Technical Summary
The prior art is difficult to effectively recover lithium ions from the mother liquor after primary lithium precipitation and prepare high-purity potassium sulfate, resulting in waste of lithium resources and insufficient potassium sulfate production.
A system was designed, including decarbonization and evaporation equipment, potassium Glauber's freezing crystal kettle, sodium sulfate freezing crystal kettle, potassium Glauber's reactor and potassium sulfate subsystem. By separating potassium Glauber's salt and sodium sulfate, potassium Glauber's salt reactor and potassium sulfate subsystem, it uses potassium Glauber's salt to react with potassium chloride. , the product is isolated to obtain high purity potassium sulfate, and the dried product is obtained by a potassium sulfate drying packaging system.
It has achieved efficient recovery of lithium ions and prepared high-purity potassium sulfate from the mother liquor after primary lithium precipitation, which has improved the utilization rate of lithium resources and the yield of potassium sulfate, and has high economic value.
Smart Images
Figure CN222151964U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of chemical industry, and specifically relates to a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor. Background Art
[0002] Potassium sulfate is an important chemical, widely used in agriculture, chemical industry, medicine and other fields. For example, in agriculture, it can be used as high-quality chlorine-free potassium fertilizer; in industry, it can be used to manufacture chemical products such as glass, phosphates, dyes, pigments, gunpowder, etc. In addition, industrial potassium sulfate can also be used to manufacture electronic chemicals such as batteries, electrolytes, and electroplating solutions. Industrial potassium sulfate is an important pharmaceutical raw material that can be used to manufacture drugs, cosmetics, oral cleaners and other products. my country's potassium sulfate production is relatively small, mainly relying on imports, and the price is relatively expensive.
[0003] Using lithium ore as raw material, the sulfuric acid method is an important means of obtaining lithium in the prior art. The sulfuric acid method is to use sulfuric acid to dissolve the metal oxides in the lithium ore to generate soluble sulfate lithium sulfate to obtain acidified clinker. After the acidified clinker is pulped and impurity removed, lithium is precipitated once, and the precipitate is refined to obtain lithium carbonate. The mother liquor after the first lithium precipitation contains not only some lithium ions, but also Na + , K + wait.
[0004] Therefore, providing a system that can not only recover lithium ions from the mother liquor after primary lithium precipitation, but also prepare high-purity potassium sulfate has become an urgent problem to be solved by technicians in this field. Utility Model Content
[0005] The utility model aims to provide a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, which can not only recover lithium ions in the mother liquor after lithium precipitation once, but also obtain high-purity potassium sulfate.
[0006] The utility model discloses a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, comprising a primary lithium precipitation mother liquor clear liquid tank, a decarbonization evaporation device, a glauberite freezing crystallization kettle, a glauberite collecting tank, a glauberite reaction kettle, and a potassium sulfate subsystem connected in sequence; a sodium sulfate freezing crystallization kettle is also connected to the glauberite freezing crystallization kettle.
[0007] The decarbonization evaporation equipment is connected with a concentrated sulfuric acid delivery pipe, and the potassium sulfate subsystem is connected with a potassium sulfate output line.
[0008] Furthermore, the sodium sulfate freezing crystallization kettle is sequentially connected to a sodium sulfate collecting tank, a sodium sulfate reaction kettle, and a glauber's salt subsystem, and the glauber's salt subsystem is connected to the glauber's salt reaction kettle.
[0009] Furthermore, the glauber's salt subsystem includes a second glauber's salt freezing crystallization kettle connected to the sodium sulfate reactor, and a second MVR evaporator connected to the second glauber's salt freezing crystallization kettle; the second MVR evaporator is connected to the glauber's salt reactor, and the second glauber's salt freezing crystallization kettle is connected to a first sodium chloride output line.
[0010] Furthermore, the potassium sulfate subsystem includes a potassium sulfate and sodium chloride freezing crystallization kettle connected to the potassium sulfate reactor, and a third MVR evaporator connected to the potassium sulfate and sodium chloride freezing crystallization kettle; the potassium sulfate and sodium chloride freezing crystallization kettle is connected to the second sodium chloride output line, and the third MVR evaporator is connected to the potassium sulfate output line. Furthermore, the sodium sulfate reactor is connected to the first potassium chloride delivery line.
[0011] The glauber's salt reactor is connected to the second potassium chloride conveying line.
[0012] Furthermore, it also includes a potassium sulfate drying and packaging system, and the potassium sulfate subsystem is connected to the potassium sulfate drying and packaging system via a potassium sulfate output line.
[0013] Furthermore, the decarbonization evaporation equipment includes a decarbonization kettle connected to the primary lithium precipitation mother liquor clear liquid tank, and an MVR evaporator connected to the decarbonization kettle; the concentrated sulfuric acid delivery pipe is connected to the decarbonization kettle, and the MVR evaporator is connected to the potassium glauberite freezing crystallization kettle.
[0014] Furthermore, the glauber's salt freezing crystallization kettle is connected with the sodium sulfate freezing crystallization kettle via a potassium precipitation mother liquor conveying line.
[0015] Furthermore, the glauberite freezing crystallization kettle is connected to the glauberite collecting tank via a glauberite transmission line;
[0016] The glauberite collecting tank is connected to the glauberite reaction kettle via the first glauberite conveying line.
[0017] Furthermore, the sodium sulfate freezing crystallization kettle is connected to the sodium sulfate collecting tank via a sodium sulfate transmission line;
[0018] The sodium sulfate collecting tank is connected to the sodium sulfate reaction kettle via a first sodium sulfate conveying line;
[0019] The sodium sulfate reactor is connected to the glauber's salt system via a second glauber's salt conveying line;
[0020] The glauber's salt subsystem is connected to the glauber's salt reactor via the third glauber's salt conveying line;
[0021] The glauber's salt reactor is connected to the potassium sulfate subsystem via a potassium sulfate and sodium chloride mixture conveying line.
[0022] Furthermore, the sodium sulfate freezing crystallization kettle is connected to a sodium precipitation mother liquor external transmission line, and the sodium precipitation mother liquor external transmission line is connected to a secondary lithium precipitation system.
[0023] Compared with the prior art, the utility model has the following beneficial effects:
[0024] The utility model has a simple structure and a scientific and reasonable design. The utility model separates glauberite and sodium sulfate from the primary lithium precipitation mother liquor by setting up a decarbonization evaporation device, a glauberite freezing crystallization kettle, and a sodium sulfate freezing crystallization kettle, and then converts sodium sulfate into glauberite by setting up a sodium sulfate reaction kettle and a glauberite subsystem; by setting up a glauberite reaction kettle and a potassium sulfate subsystem, glauberite reacts with potassium chloride and separates the products to obtain sodium chloride and potassium sulfate respectively, and by setting up a potassium sulfate drying and packaging system, a dry potassium sulfate product is obtained. The utility model can obtain a high-purity potassium sulfate product, and the mother liquor after sodium precipitation after the sodium sulfate freezing crystallization kettle is subjected to secondary lithium precipitation to obtain battery-grade lithium carbonate. The utility model has extremely high economic value. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Attached Figure 1 This is a system structure diagram of the utility model.
[0026] Attached Figure 2 This is the overall structure diagram of the potassium glauber's salt system of the utility model.
[0027] Attached Figure 3 This is a structural diagram of the potassium sulfate subsystem of the utility model.
[0028] The names corresponding to the reference numerals are:
[0029] 1-primary lithium precipitation mother liquor clear liquid tank, 2-glauber's salt freezing crystallization kettle, 3-glauber's salt collecting tank, 4-sodium sulfate freezing crystallization kettle, 5-sodium sulfate collecting tank, 6-sodium sulfate reactor, 7-glauber's salt subsystem, 8-glauber's salt reactor, 9-potassium sulfate subsystem, 10-potassium sulfate drying and packaging system, 11-decarbonization kettle, 12-MVR evaporator;
[0030] 71-the second glauberite freezing crystallization kettle, 72-the second MVR evaporator, 73-the first sodium analysis liquid conveying line;
[0031] 91-potassium sulfate and sodium chloride freezing crystallization kettle, 92-third MVR evaporator; 93-second sodium analysis liquid conveying line;
[0032] 101-concentrated sulfuric acid delivery pipe, 102-potassium sulfate output line, 103-first potassium chloride delivery line, 104-second potassium chloride delivery line, 105-first sodium chloride output line, 106-second sodium chloride output line, 107-potassium precipitation mother liquor delivery line, 108-glauber's salt delivery line, 109-first glauber's salt delivery line, 110-sodium sulfate delivery line, 111-first sodium sulfate delivery line, 112-second glauber's salt delivery line, 113-third glauber's salt delivery line, 114-potassium sulfate and sodium chloride mixture delivery line, 115-sodium precipitation mother liquor delivery line, 116-lithium precipitation mother liquor delivery line; 117-decarbonization mother liquor delivery line; 118-concentrated mother liquor delivery line. DETAILED DESCRIPTION
[0033] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings. 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 making creative work are within the scope of protection of the utility model.
[0034] Example 1.
[0035] As attached Figure 1 As shown, the utility model provides a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, comprising a primary lithium precipitation mother liquor clear liquid tank 1, a decarbonization evaporation device, a glauberite freezing crystallization kettle 2, a glauberite collecting tank 3, a glauberite reaction kettle 8, and a potassium sulfate subsystem 9, which are connected in sequence; a sodium sulfate freezing crystallization kettle 4 is also connected to the glauberite freezing crystallization kettle 2,
[0036] The decarbonization evaporation equipment is connected to a concentrated sulfuric acid delivery pipe 101 .
[0037] The potassium sulfate subsystem 9 includes a potassium sulfate and sodium chloride freezing crystallization kettle 91 connected from the potassium sulfate reactor 8, and a third MVR evaporator 92 connected from the potassium sulfate and sodium chloride freezing crystallization kettle 91; the potassium sulfate and sodium chloride freezing crystallization kettle 91 is connected to a second sodium chloride output line 106, and the third MVR evaporator 92 is connected to a potassium sulfate output line 102. The potassium sulfate and sodium chloride freezing crystallization kettle 91 and the third MVR evaporator 92 are connected via a second sodium precipitation liquid delivery line 93.
[0038] The utility model has a simple structure and a scientific and reasonable design. By arranging a decarbonization evaporation device, a glauberite freezing crystallization kettle and a sodium sulfate freezing crystallization kettle, glauberite and sodium sulfate are separated from a primary lithium precipitation mother liquor. By arranging a glauberite reaction kettle and a potassium sulfate subsystem, glauberite and potassium chloride are reacted, and the products are separated to obtain sodium chloride and potassium sulfate respectively.
[0039] Example 2.
[0040] As attached Figure 1 As shown, the utility model discloses a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, comprising a primary lithium precipitation mother liquor clear liquid tank 1, a decarbonization evaporation device, a glauberite freezing crystallization kettle 2, a glauberite collecting tank 3, a glauberite reaction kettle 8, and a potassium sulfate subsystem 9 which are sequentially connected; a sodium sulfate freezing crystallization kettle 4 is also connected to the glauberite freezing crystallization kettle 2,
[0041] The decarbonization evaporation equipment is connected to a concentrated sulfuric acid delivery pipe 101, and the potassium sulfate subsystem 9 is connected to a potassium sulfate output line 102. The sodium sulfate freezing crystallization kettle 4 is sequentially connected to a sodium sulfate collection tank 5, a sodium sulfate reactor 6, and a potassium glauber's salt subsystem 7, and the potassium glauber's salt subsystem 7 is connected to the potassium glauber's salt reactor 8.
[0042] The glauberite subsystem 7 includes a second glauberite freezing crystallization kettle 71 connected to the sodium sulfate reactor 6, and a second MVR evaporator 72 connected to the second glauberite freezing crystallization kettle 71; the second MVR evaporator 72 is connected to the glauberite reactor 8, and the second glauberite freezing crystallization kettle 71 is connected to a first sodium chloride output line 105.
[0043] The potassium sulfate subsystem 9 includes a potassium sulfate and sodium chloride freezing crystallization kettle 91 connected to the potassium sulfate and sodium chloride freezing crystallization kettle 8, and a third MVR evaporator 92 connected to the potassium sulfate and sodium chloride freezing crystallization kettle 91; the potassium sulfate and sodium chloride freezing crystallization kettle 91 is connected to the second sodium chloride output line 106, and the third MVR evaporator 92 is connected to the potassium sulfate output line 102. The potassium sulfate and sodium chloride freezing crystallization kettle 91 and the third MVR evaporator 92 are connected via the second sodium analysis liquid delivery line 93. This embodiment 2 provides a more preferred structure based on embodiment 1, specifically: the potassium sulfate freezing crystallization kettle 2 is sequentially connected to the sodium sulfate collecting tank 5, the sodium sulfate reactor 6, and the potassium glauberite subsystem 7, and the potassium glauberite subsystem 7 is connected to the potassium glauberite reactor 8; and the specific structure of the potassium glauberite subsystem 7 is provided.
[0044] In this embodiment, sodium sulfate is converted into glauber's salt by adding a sodium sulfate reactor and a glauber's salt subsystem; and the sodium sulfate is combined with the glauber's salt precipitated from the decarbonization mother liquor, and the glauber's salt is reacted with potassium chloride through a glauber's salt reactor and a potassium sulfate subsystem, and the products are separated to obtain sodium chloride and potassium sulfate, respectively. A potassium sulfate drying and packaging system is provided to obtain a dry high-purity potassium sulfate product.
[0045] Example 3
[0046] As attached Figure 1As shown, the utility model discloses a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, comprising a primary lithium precipitation mother liquor clear liquid tank 1, a decarbonization evaporation device, a glauberite freezing crystallization kettle 2, a glauberite collecting tank 3, a glauberite reaction kettle 8, and a potassium sulfate subsystem 9 which are sequentially connected; a sodium sulfate freezing crystallization kettle 4 is also connected to the glauberite freezing crystallization kettle 2,
[0047] The decarbonization evaporation equipment is connected to a concentrated sulfuric acid delivery pipe 101, and the potassium sulfate subsystem 9 is connected to a potassium sulfate output line 102. The sodium sulfate freezing crystallization kettle 4 is sequentially connected to a sodium sulfate collection tank 5, a sodium sulfate reactor 6, and a potassium glauber's salt subsystem 7, and the potassium glauber's salt subsystem 7 is connected to the potassium glauber's salt reactor 8.
[0048] The sodium sulfate reactor 6 is connected to a first potassium chloride delivery line 103.
[0049] The glauber's salt reactor 8 is connected to a second potassium chloride delivery line 104 .
[0050] The glauberite subsystem 7 includes a second glauberite freezing crystallization kettle 71 connected to the sodium sulfate reactor 6, and a second MVR evaporator 72 connected to the second glauberite freezing crystallization kettle 71; the second MVR evaporator 72 is connected to the glauberite reactor 8, and the second glauberite freezing crystallization kettle 71 is connected to a first sodium chloride output line 105.
[0051] The potassium sulfate subsystem 9 includes a potassium sulfate and sodium chloride freezing crystallization kettle 91 connected from the potassium sulfate reactor 8, and a third MVR evaporator 92 connected from the potassium sulfate and sodium chloride freezing crystallization kettle 91; the potassium sulfate and sodium chloride freezing crystallization kettle 91 is connected to a second sodium chloride output line 106, and the third MVR evaporator 92 is connected to a potassium sulfate output line 102. The potassium sulfate and sodium chloride freezing crystallization kettle 91 and the third MVR evaporator 92 are connected via a second sodium precipitation liquid delivery line 93.
[0052] Based on Example 2, this Example 3 provides a more preferred structure of the sodium sulfate reactor 6, the glauber's salt subsystem 7, the glauber's salt reactor 8 and the potassium sulfate subsystem 9, specifically: the sodium sulfate reactor 6 is connected to the first potassium chloride delivery line 103, the glauber's salt reactor 8 is connected to the second potassium chloride delivery line 104, the glauber's salt subsystem 7 is connected to the first sodium chloride output line 105, and the potassium sulfate subsystem 9 is connected to the second sodium chloride output line 106.
[0053] Example 4
[0054] As attached Figure 1As shown, the utility model discloses a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, comprising a primary lithium precipitation mother liquor clear liquid tank 1, a decarbonization evaporation device, a glauberite freezing crystallization kettle 2, a glauberite collecting tank 3, a glauberite reaction kettle 8, and a potassium sulfate subsystem 9 which are sequentially connected; a sodium sulfate freezing crystallization kettle 4 is also connected to the glauberite freezing crystallization kettle 2,
[0055] The decarbonization evaporation equipment is connected to a concentrated sulfuric acid delivery pipe 101 , and the potassium sulfate subsystem 9 is connected to a potassium sulfate output line 102 .
[0056] The sodium sulfate freezing crystallization kettle 4 is connected to a sodium sulfate collecting tank 5, a sodium sulfate reaction kettle 6, and a glauber's salt system 7 in sequence, and the glauber's salt system 7 is connected to a glauber's salt reaction kettle 8.
[0057] The glauberite subsystem 7 includes a second glauberite freezing crystallization kettle 71 connected to the sodium sulfate reactor 6, and a second MVR evaporator 72 connected to the second glauberite freezing crystallization kettle 71; the second MVR evaporator 72 is connected to the glauberite reactor 8, and the second glauberite freezing crystallization kettle 71 is connected to a first sodium chloride output line 105.
[0058] The potassium sulfate subsystem 9 includes a potassium sulfate and sodium chloride freezing crystallization kettle 91 connected from the potassium sulfate reactor 8, and a third MVR evaporator 92 connected from the potassium sulfate and sodium chloride freezing crystallization kettle 91; the potassium sulfate and sodium chloride freezing crystallization kettle 91 is connected to a second sodium chloride output line 106, and the third MVR evaporator 92 is connected to a potassium sulfate output line 102. The potassium sulfate and sodium chloride freezing crystallization kettle 91 and the third MVR evaporator 92 are connected via a second sodium precipitation liquid delivery line 93.
[0059] It also includes a potassium sulfate drying and packaging system 10 , and the potassium sulfate subsystem 9 is connected to the potassium sulfate drying and packaging system 10 via a potassium sulfate output line 102 .
[0060] Based on Example 1, this Example 4 provides a more preferred structure. Specifically, the system of this Example further includes a potassium sulfate drying and packaging system 10, and the potassium sulfate subsystem 9 is connected to the potassium sulfate drying and packaging system 10 via a potassium sulfate output line 102. This Example obtains a dry high-purity potassium sulfate product by setting up a potassium sulfate drying and packaging system.
[0061] Example 5
[0062] As attached Figure 1 As shown, the utility model discloses a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, comprising a primary lithium precipitation mother liquor clear liquid tank 1, a decarbonization evaporation device, a glauberite freezing crystallization kettle 2, a glauberite collecting tank 3, a glauberite reaction kettle 8, and a potassium sulfate subsystem 9 which are sequentially connected; a sodium sulfate freezing crystallization kettle 4 is also connected to the glauberite freezing crystallization kettle 2.
[0063] The decarbonization evaporation equipment is connected to a concentrated sulfuric acid delivery pipe 101 , and the potassium sulfate subsystem 9 is connected to a potassium sulfate output line 102 .
[0064] The decarbonization evaporation equipment includes a decarbonization kettle 11 connected from the primary lithium precipitation mother liquor clear liquid tank 1, and an MVR evaporator 12 connected from the decarbonization kettle 11; a concentrated sulfuric acid delivery pipe 101 is connected to the decarbonization kettle 11, and the MVR evaporator 12 is connected to the potassium glauberite freezing crystallization kettle 2.
[0065] The potassium sulfate subsystem 9 includes a potassium sulfate and sodium chloride freezing crystallization kettle 91 connected from the potassium sulfate reactor 8, and a third MVR evaporator 92 connected from the potassium sulfate and sodium chloride freezing crystallization kettle 91; the potassium sulfate and sodium chloride freezing crystallization kettle 91 is connected to a second sodium chloride output line 106, and the third MVR evaporator 92 is connected to a potassium sulfate output line 102. The potassium sulfate and sodium chloride freezing crystallization kettle 91 and the third MVR evaporator 92 are connected via a second sodium precipitation liquid delivery line 93.
[0066] Based on Example 1, this Example 4 provides a more preferred structure of the decarbonization evaporation equipment. Specifically, the decarbonization evaporation equipment includes a decarbonization kettle 11 connected to the primary lithium precipitation mother liquor clear liquid tank 1, and an MVR evaporator 12 connected to the decarbonization kettle 11; a concentrated sulfuric acid delivery pipe 101 is connected to the decarbonization kettle 11, and the MVR evaporator 12 is connected to the potassium glauberite freezing crystallization kettle 2.
[0067] The primary lithium precipitation mother liquor clear liquid tank 1 is connected to the decarbonization kettle 11 via a lithium precipitation mother liquor conveying line 116, the decarbonization kettle 11 is connected to the MVR evaporator 12 via a decarbonization mother liquor conveying line 117; the MVR evaporator 12 is connected to the potassium glauberite freezing crystallization kettle 2 via a concentrated mother liquor conveying line 118.
[0068] Sulfuric acid solution is added to the primary lithium precipitation mother liquor to remove carbonate; the decarbonized mother liquor is concentrated by MVR evaporator and the concentrated mother liquor is sent to the potassium glauberite freezing crystallization kettle.
[0069] Example 6
[0070] As attached Figure 1 As shown, the utility model discloses a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, comprising a primary lithium precipitation mother liquor clear liquid tank 1, a decarbonization evaporation device, a glauberite freezing crystallization kettle 2, a glauberite collecting tank 3, a glauberite reaction kettle 8, a potassium sulfate subsystem 9, a potassium sulfate drying and packaging system 10, and a sodium sulfate freezing crystallization kettle 4 connected in sequence.
[0071] The decarbonization evaporation equipment includes a decarbonization kettle 11 connected from the primary lithium precipitation mother liquor clear liquid tank 1, and an MVR evaporator 12 connected from the decarbonization kettle 11; the decarbonization kettle 11 is connected to a concentrated sulfuric acid delivery pipe 101, and the MVR evaporator 12 is connected to the potassium glauberite freezing crystallization kettle 2.
[0072] The sodium sulfate freezing crystallization kettle 4 is connected to a sodium sulfate collecting tank 5, a sodium sulfate reaction kettle 6, and a glauber's salt system 7 in sequence, and the glauber's salt system 7 is connected to a glauber's salt reaction kettle 8.
[0073] The sodium sulfate reactor 6 is connected to a first potassium chloride delivery line 103 , and the glauber's salt reactor 8 is connected to a second potassium chloride delivery line 104 .
[0074] The glauber's salt subsystem 7 is connected to a first sodium chloride output line 105 , and the potassium sulfate subsystem 9 is connected to a second sodium chloride output line 106 . The potassium sulfate subsystem 9 is connected to the potassium sulfate drying and packaging system 10 via the potassium sulfate output line 102 .
[0075] The glauberite freezing crystallization kettle 2 is connected to the sodium sulfate freezing crystallization kettle 4 via the potassium precipitation mother liquor conveying line 107, and the glauberite freezing crystallization kettle 2 is connected to the glauberite collecting tank 3 via the glauberite external transmission line 108; the glauberite collecting tank 3 is connected to the glauberite reaction kettle 8 via the first glauberite conveying line 109.
[0076] The sodium sulfate freezing crystallization kettle 4 is connected to the sodium sulfate collecting tank 5 via a sodium sulfate transmission line 110; the sodium sulfate collecting tank 5 is connected to the sodium sulfate reactor 6 via a first sodium sulfate transmission line 111; the sodium sulfate reactor 6 is connected to the glauber's salt subsystem 7 via a second glauber's salt transmission line 112; the glauber's salt subsystem 7 is connected to the glauber's salt reactor 8 via a third glauber's salt transmission line 113; the glauber's salt reactor 8 is connected to the potassium sulfate subsystem 9 via a potassium sulfate and sodium chloride mixture transmission line 114.
[0077] The sodium sulfate freezing crystallization kettle 4 is connected to a sodium precipitation mother liquor external transmission line 115, and the sodium precipitation mother liquor external transmission line 115 is connected to a secondary lithium precipitation system.
[0078] Example 7
[0079] As attached Figure 1 As shown, the utility model discloses a system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, comprising a primary lithium precipitation mother liquor clear liquid tank 1, a decarbonization evaporation device, a glauberite freezing crystallization kettle 2, a glauberite collecting tank 3, a glauberite reaction kettle 8, a potassium sulfate subsystem 9, a potassium sulfate drying and packaging system 10, and a sodium sulfate freezing crystallization kettle 4 connected in sequence.
[0080] The decarbonization evaporation equipment includes a decarbonization kettle 11 connected from the primary lithium precipitation mother liquor clear liquid tank 1, and an MVR evaporator 12 connected from the decarbonization kettle 11; the decarbonization kettle 11 is connected to a concentrated sulfuric acid delivery pipe 101, and the MVR evaporator 12 is connected to the potassium glauberite freezing crystallization kettle 2.
[0081] The sodium sulfate freezing crystallization kettle 4 is connected to a sodium sulfate collecting tank 5, a sodium sulfate reaction kettle 6, and a glauber's salt system 7 in sequence, and the glauber's salt system 7 is connected to a glauber's salt reaction kettle 8.
[0082] The sodium sulfate reactor 6 is connected to a first potassium chloride delivery line 103 , and the glauber's salt reactor 8 is connected to a second potassium chloride delivery line 104 .
[0083] The sodium glauberite subsystem 7 is connected to a first sodium chloride output line 105, and the potassium sulfate subsystem 9 is connected to a second sodium chloride output line 106.
[0084] The potassium sulfate subsystem 9 is connected to the potassium sulfate drying and packaging system 10 via the potassium sulfate output line 102 .
[0085] The glauberite freezing crystallization kettle 2 is connected to the sodium sulfate freezing crystallization kettle 4 via the potassium precipitation mother liquor conveying line 107, and the glauberite freezing crystallization kettle 2 is connected to the glauberite collecting tank 3 via the glauberite external transmission line 108; the glauberite collecting tank 3 is connected to the glauberite reaction kettle 8 via the first glauberite conveying line 109.
[0086] The sodium sulfate freezing crystallization kettle 4 is connected to the sodium sulfate collecting tank 5 via a sodium sulfate transmission line 110; the sodium sulfate collecting tank 5 is connected to the sodium sulfate reactor 6 via a first sodium sulfate transmission line 111; the sodium sulfate reactor 6 is connected to the glauber's salt subsystem 7 via a second glauber's salt transmission line 112; the glauber's salt subsystem 7 is connected to the glauber's salt reactor 8 via a third glauber's salt transmission line 113; the glauber's salt reactor 8 is connected to the potassium sulfate subsystem 9 via a potassium sulfate and sodium chloride mixture transmission line 114.
[0087] The sodium sulfate freezing crystallization kettle 4 is connected to a sodium precipitation mother liquor external transmission line 115, and the sodium precipitation mother liquor external transmission line 115 is connected to a secondary lithium precipitation system.
[0088] The glauberite subsystem 7 includes a second glauberite freezing crystallization kettle 71 connected to the sodium sulfate reactor 6, and a second MVR evaporator 72 connected to the second glauberite freezing crystallization kettle 71; the second MVR evaporator 72 is connected to the glauberite reactor 8, and the second glauberite freezing crystallization kettle 71 is connected to a first sodium chloride output line 105.
[0089] The potassium sulfate subsystem 9 includes a potassium sulfate and sodium chloride freezing crystallization kettle 91 connected from the potassium sulfate reactor 8, and a third MVR evaporator 92 connected from the potassium sulfate and sodium chloride freezing crystallization kettle 91; the potassium sulfate and sodium chloride freezing crystallization kettle 91 is connected to a second sodium chloride output line 106, and the third MVR evaporator 92 is connected to a potassium sulfate output line 102. The potassium sulfate and sodium chloride freezing crystallization kettle 91 and the third MVR evaporator 92 are connected via a second sodium precipitation liquid delivery line 93.
[0090] When the utility model is used, the primary lithium precipitation mother liquor of producing lithium carbonate by sulfuric acid process is used as raw material, and the method steps are as follows:
[0091] S1. Decarbonization and evaporation: The mother liquor of lithium precipitation in the primary lithium precipitation clear liquid tank is sent to the decarbonization kettle to generate carbon dioxide for decarbonization under the action of sulfuric acid; the decarbonization mother liquor enters the MVR evaporator for evaporation and concentration; the lithium sulfate content in the primary lithium precipitation mother liquor is less than or equal to 7wt.%, the sodium sulfate content is 5-27wt.%, and the potassium sulfate content is 8-19wt.%.
[0092] S2. Separation of glauberite: The concentrated mother liquor is cooled to 25°C ± 5°C, glauberite is precipitated, and the glauberite enters the glauberite collection tank 3; the potassium mother liquor enters the sodium sulfate freezing crystallization kettle;
[0093] S3. Separation of sodium sulfate: The potassium precipitation mother liquor is cooled to ≤0°C in the sodium sulfate freezing crystallization kettle, sodium sulfate is precipitated, and the sodium sulfate enters the sodium sulfate collection tank; the sodium precipitation mother liquor enters the secondary lithium precipitation system.
[0094] S4. After sodium sulfate reacts with an added potassium chloride solution in the sodium sulfate reactor to generate glauberite and sodium chloride, the reaction materials are sent to the glauberite subsystem 7, in which glauberite is first crystallized and separated, and then sodium chloride is separated by evaporation and crystallization, and the glauberite is sent to the glauberite reactor, and the glauberite in the glauberite collecting tank 3 is also sent to the glauberite reactor; the sodium chloride is sent out of the first sodium chloride output line; S5. After the glauberite reacts with the added potassium chloride solution in the glauberite reactor, the reactant is sent to the potassium sulfate subsystem;
[0095] S6. In the potassium sulfate subsystem, the reactant of step S5 is first cooled to -5 to 0°C, potassium sulfate is separated by crystallization, and then sodium chloride is separated by evaporation and crystallization. The sodium chloride is sent out of the boundary through the second sodium chloride output line; the potassium sulfate is sent to the potassium sulfate drying and packaging system.
[0096] S7. Secondary lithium precipitation: Sodium carbonate is added to the sodium precipitation mother liquor, the temperature is raised, lithium is precipitated for secondary precipitation, and the obtained precipitate is lithium carbonate with a purity of ≥90%. The precipitate obtained by the secondary lithium precipitation is stirred, washed, carbonized, heat-precipitated, and dried to obtain battery-grade lithium carbonate.
[0097] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention to illustrate the technical solution of the present invention, rather than limiting it, and certainly not limiting the patent scope of the present invention; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention; that is to say, any changes or embellishments made to the main design concept and spirit of the present invention that have no substantive significance, and the technical problems they solve are still consistent with the present invention, should be included in the protection scope of the present invention; in addition, the direct or indirect application of the technical solution of the present invention in other related technical fields is also included in the patent protection scope of the present invention.
Claims
1. A system for preparing high-purity potassium sulfate from lithium precipitation mother liquor, characterized in that: The invention comprises a primary lithium precipitation mother liquor clear liquid tank (1), a decarbonization evaporation device, a glauberite freezing crystallization kettle (2), a glauberite collecting tank (3), a glauberite reaction kettle (8), and a potassium sulfate subsystem (9) which are connected in sequence; a sodium sulfate freezing crystallization kettle (4) is also connected to the glauberite freezing crystallization kettle (2). The decarbonization evaporation equipment is connected to a concentrated sulfuric acid delivery pipe (101), and the potassium sulfate subsystem (9) is connected to a potassium sulfate output line (102).
2. The system for preparing high-purity potassium sulfate from lithium precipitation mother liquor according to claim 1, characterized in that: The sodium sulfate freezing crystallization kettle (4) is connected to a sodium sulfate collecting tank (5), a sodium sulfate reaction kettle (6), and a glauber's salt system (7) in sequence, and the glauber's salt system (7) is connected to a glauber's salt reaction kettle (8).
3. The system for preparing high-purity potassium sulfate from lithium precipitation mother liquor according to claim 2, characterized in that: The glauberite subsystem (7) comprises a second glauberite freezing crystallization kettle (71) connected to the sodium sulfate reaction kettle (6), and a second MVR evaporator (72) connected to the second glauberite freezing crystallization kettle (71); the second MVR evaporator (72) is connected to the glauberite reaction kettle (8), and the second glauberite freezing crystallization kettle (71) is connected to a first sodium chloride output line (105).
4. A system for preparing high-purity potassium sulfate from lithium precipitation mother liquor according to any one of claims 1 to 3, characterized in that: The potassium sulfate subsystem (9) includes a potassium sulfate and sodium chloride freezing crystallization kettle (91) connected from the glauber's salt reaction kettle (8), and a third MVR evaporator (92) connected from the potassium sulfate and sodium chloride freezing crystallization kettle (91); The potassium sulfate and sodium chloride freezing crystallization kettle (91) is connected to a second sodium chloride output line (106), and the third MVR evaporator (92) is connected to a potassium sulfate output line (102).
5. The system for preparing high-purity potassium sulfate from lithium precipitation mother liquor according to claim 2, characterized in that: The sodium sulfate reactor (6) is connected to a first potassium chloride delivery line (103). The glauber's salt reaction kettle (8) is connected to a second potassium chloride delivery line (104).
6. The system for preparing high-purity potassium sulfate from lithium precipitation mother liquor according to claim 1, characterized in that: It also includes a potassium sulfate drying and packaging system (10), and the potassium sulfate subsystem (9) is connected to the potassium sulfate drying and packaging system (10) via a potassium sulfate output line (102).
7. The system for preparing high-purity potassium sulfate from lithium precipitation mother liquor according to claim 1, characterized in that: The decarbonization evaporation equipment comprises a decarbonization kettle (11) connected to a primary lithium precipitation mother liquor clear liquid tank (1), and an MVR evaporator (12) connected to the decarbonization kettle (11); a concentrated sulfuric acid delivery pipe (101) is connected to the decarbonization kettle (11), and the MVR evaporator (12) is connected to a potassium glauberite freezing crystallization kettle (2).
8. The system for preparing high-purity potassium sulfate from lithium precipitation mother liquor according to claim 1, characterized in that: The glauberite freezing crystallization kettle (2) is connected to the sodium sulfate freezing crystallization kettle (4) via a potassium precipitation mother liquor delivery line (107); the glauberite freezing crystallization kettle (2) is connected to the glauberite collection tank (3) via a glauberite delivery line (108); The glauberite collecting tank (3) is connected to the glauberite reaction kettle (8) via a first glauberite conveying line (109).
9. The system for preparing high-purity potassium sulfate from lithium precipitation mother liquor according to claim 1, characterized in that: The sodium sulfate freezing crystallization kettle (4) is connected to the sodium sulfate collecting tank (5) via a sodium sulfate transmission line (110); The sodium sulfate collecting tank (5) is connected to the sodium sulfate reaction kettle (6) via a first sodium sulfate conveying line (111); The sodium sulfate reaction kettle (6) is connected to the glauber's salt system (7) via a second glauber's salt conveying line (112); The glauber's salt subsystem (7) is connected to the glauber's salt reaction kettle (8) via a third glauber's salt conveying line (113); The glauber's salt reaction kettle (8) is connected to the potassium sulfate subsystem (9) via a potassium sulfate and sodium chloride mixture conveying line (114).
10. The system for preparing high-purity potassium sulfate from lithium precipitation mother liquor according to claim 1, characterized in that: The sodium sulfate freezing crystallization kettle (4) is connected to a sodium precipitation mother liquor external transmission line (115), and the sodium precipitation mother liquor external transmission line (115) is connected to a secondary lithium precipitation system.