Method for quickly depositing lithium carbonate from lithium bicarbonate solution

Abstract

The invention provides a method of rapid precipitation of lithium carbonate in lithium bicarbonate solution. The method adopts a heatable negative-pressure apparatus and water-soluble organic solvents such as ethanol and propanol, etc., to conduct a constant volume reaction by stirring under the controlled temperature at 80-180 DEG C and the negative pressure of an container of 0.01-0.10 MPa so as to dissolve the lithium bicarbonate and precipitate the lithium carbonate; the precipitation mother liquor is recoverable for reuse. The invention not only overcomes the problems of a 'wall-cling effect' in an ordinary evaporation and precipitation course and a 'concentration and entrainment effect' of water-soluble impurity ions, but also quickens the precipitation speed with the precipitation course only consuming around 20 min, which is 2 to 3 times of an ordinary evaporation and precipitation method and the precipitation rate of the lithium is enhanced with a single precipitation rate ofthe lithium carbonate of above 87 percent and the overall recovery rate of the lithium of above 94 percent.

Description

technical field [0001] The invention belongs to the field of chemical engineering, and relates to a method for precipitating lithium carbonate from a lithium bicarbonate solution, in particular to a method for rapidly precipitating lithium carbonate from a lithium bicarbonate solution by using a thermal negative pressure device and using a water-soluble organic solvent as a medium . Background technique [0002] The carbonization-decomposition method to prepare high-purity lithium carbonate is favored by people for its advantages of simple operation, no pollution, low cost, stable product quality, and high recovery rate of total lithium. In this method, crude lithium carbonate is first utilized CO 2 Convert it into soluble lithium bicarbonate by carbonation, go through the ion removal step, and then heat and decompose it to obtain lithium carbonate product. Among them, a key step is the decomposition of lithium bicarbonate solution, that is, the precipitation of lithium ca...

AI Technical Summary

Problems solved by technology

[0003] Precipitation of lithium carbonate from lithium bicarbonate solution, the most commonly used method is the common evaporation precipitation method, due to the reduction of water evaporation in the system, the common evaporation precipitation method is easy to form the "wall effect" of precipitation and water-soluble impurities during the precipitation process. The "concentration entrainment effect" of ions affects the purity of the product and increases the energy consumption of the process