Lepidolite is an important raw material for new energy lithium materials. In order to let more people understand the refining method of this lepidolite lithium extraction MVR equipment, Kang Jinghui evaporator will introduce the equipment and process flow of the lithium extraction MVR production line for lepidolite.
Lepidolite lithium extraction MVR equipment
Lithium is purified from spodumene lepidolite, and the acidified lithium sulfate solution is concentrated by MVR evaporator and the salt components in the crystalline lithium immersion mother liquor are used to ensure continuous and smooth process production, while reducing energy consumption and operating costs.
Lepidolite lithium extraction MVR equipment process
Lepidolite lithium extraction MVR equipment is mainly used in the evaporation and concentration stage of lepidolite purification liquid
Due to the low concentration of lithium sulfate and the low precipitation rate of lithium, the purification solution cannot be directly used for lithium precipitation or lithium chloride production, and the purification solution needs to be adjusted to pH6 6 with sulfuric acid first5. Evaporation and concentration by three-effect evaporator to make the concentration of lithium sulfate in the concentrate reach 200g L (including Li2O 60g L). The concentrate is separated by pressure filtration, the filtrate is used for the next process, and the filter cake is returned to the slurry leaching after the slag.
The MVR evaporation, concentration and crystallization process of lithium extraction from lepidolite includes three parts: stock solution preheating, MVR evaporation, concentration crystallization and MVR vapor compression.
MVR evaporation concentration crystallization process The first-stage forced circulation MVR evaporation and concentration process is adopted, and the preheating part of the stock solution includes the preheating part of non-condensable gas and the preheating part of condensate water, and the waste heat of the system is fully used to preheat the stock solution.
In the MVR evaporation, concentration and crystallization part, the preheated stock solution enters the MVR first-stage forced circulation evaporation device, and the secondary steam compressed by the steam compressor is used to heat it, and the solution begins to evaporate and concentrate.
When the solution is concentrated to a certain concentration, the slurry is discharged into the thickener through the first-class control system, the mother liquor and the plasma are preliminarily separated in the thickener, the supernatant flows into the mother liquor tank for storage, the thickened plasma enters the centrifuge for preliminary separation, and the separated salt is used as NaCl product, and the centrifuged mother liquor returns to the mother liquor tank and is transported to the lithium production process workshop through the mother liquor pump;
Lepidolite lithium extraction MVR equipment lithium carbonate section:
Lithium carbonate production section
The finished liquid and soda ash solution (containing Na2CO3 300G L) were added to the evaporation lithium tank, and the lithium was evaporated and precipitated (constant temperature for 2h after boiling), and the lithium precipitation rate was about 85% due to the small solubility of lithium carbonate. After lithium precipitation, a centrifuge was used to separate a crude lithium carbonate (containing filtrate less than 10%) and a lithium mother liquor while it was hot.
The mother liquor contains a large amount of sodium sulfate and higher lithium sulfate (about 15% of the total), and the soda ash solution (containing Na2CO3 300g L) is added to the secondary lithium immersion to obtain the second crude product and the second mother liquor, the mother liquor is neutralized by acid, and the sodium hydroxide is adjusted to pH, and the by-product anhydrous sodium sulfate and sodium precipitation mother liquor are separated by evaporation crystallization and centrifugation, and the by-product of anhydrous sodium sulfate is dried and packaged by gas flow. Sodium precipitation mother liquor is returned to ** with a mother liquor.
The primary crude lithium carbonate and the secondary crude product attachment liquid contain Na2SO4 and other impurities, and then use clean water to stir at about 90, the washing liquid is sent to the alkali, and after washing, the wetland refined lithium carbonate is separated by a centrifuge while it is hot, and then dried by a far-infrared dryer, and the iron wire filings and other sundries shed by the dryer are removed by magnetic separation, and then crushed by air flow, packaged and put into storage.
Application of lithium extraction MVR equipment for lepidolite
The whole set of MVR evaporator can be used in the evaporation, concentration, crystallization and drying of manganese sulfate, cobalt sulfate, lithium sulfate, nickel sulfate, zinc sulfate, lithium hydroxide, lithium carbonate, cobalt chloride, lithium chloride and other raw materials in the production of lithium battery raw materials.
Lithium battery MVR evaporator can also be applied to the new energy battery industry wastewater treatment technology, the product production wastewater is treated with zero discharge, such as the production of ternary materials (precursors), lithium iron phosphate, copper foil and other production processes of various wastewater, including high salinity wastewater, such as ammonium chloride, ammonium sulfate, sodium chloride, sodium sulfate, etc.