Method for producing high purity lithium sulfate from waste saggar
AssigneeKoreaseparation Co., Ltd.
InventorWon Hong SONG
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Abstract
The present invention provides an optimized method for recovering high-purity lithium sulfate from a lithium-containing composite oxide deposited on an eroded surface of a waste sagger discarded. Therefore, when the method for producing high-purity lithium sulfate from a waste sagger of the present invention is used, it is expected not only to be able to produce high-purity lithium sulfate that can be used for manufacturing lithium secondary batteries by recycling a discarded waste sagger, but also to be able to recycle a positive electrode active material, iron oxide, alumina, silicate, and calcium carbonate obtained as by-products during the production process of the lithium sulfate.
Claims6
A method for producing high-purity lithium sulfate, the method comprising:
- a first step of crushing a waste sagger to produce a waste sagger crushed material;
- a second step of adding an alkali leaching agent and water to the waste sagger crushed material and then allowing a reaction to occur therebetween to prepare a waste sagger crushed material dissolution reaction slurry;
- a third step of performing primary solid-liquid separation on the waste sagger crushed material dissolution reaction slurry;
- a fourth step of preparing a solid phase obtained through the primary solid-liquid separation as a suspension, and then performing a primary wet magnetic separation process to obtain a first magnetic complex and a first non-magnetic complex;
- a fifth step of preparing the first non-magnetic complex as a suspension, and then performing a secondary wet magnetic separation process to obtain a second magnetic complex and a second non-magnetic complex;
- a sixth step of introducing water and a leaching agent to the second non-magnetic complex, and then allowing a reaction to occur therebetween to prepare a lithium leaching reaction liquid;
- a seventh step of performing secondary solid-liquid separation on the lithium leaching reaction liquid;
- an eighth step of adjusting the pH of a filtrate obtained in a liquid phase through the secondary solid-liquid separation to 6 to 8 to prepare a neutralization reaction liquid;
- a ninth step of performing tertiary solid-liquid separation on the neutralization reaction liquid;
- a tenth step of performing reverse osmosis concentration on a filtrate obtained in a liquid phase through the tertiary solid-liquid separation;
- an eleventh step of performing evaporation and concentration on a concentration liquid obtained through the reverse osmosis concentration process;
- and
- a twelfth step of performing quaternary solid-liquid separation on a concentration liquid obtained through the evaporation and concentration to obtain high-purity lithium sulfate in a solid phase.
Dependencies are inferred from the claim text.