Method for quickly depositing lithium carbonate from lithium bicarbonate solution

Abstract

The invention provides a method for rapidly precipitating lithium carbonate from lithium bicarbonate solution. The method adopts a heatable negative pressure device, uses water-soluble organic solvents such as ethanol, propanol, etc., controls the temperature at 80-180°C, and stirs under the condition of negative pressure in the container at 0.01-0.10MPa to carry out isovolumic reaction, so that bicarbonate Lithium decomposes, precipitates lithium carbonate, and the precipitated mother liquor can be recycled and reused. The present invention not only overcomes the problems of "wall-hanging effect" of precipitation and "concentration entrainment effect" of water-soluble impurity ions in the ordinary evaporation and precipitation process, but also accelerates the precipitation rate: the precipitation process only takes about 20 minutes, which is faster than the ordinary evaporation and precipitation method. 2 to 3 times; the precipitation rate of lithium is improved: the single precipitation rate of lithium carbonate reaches more than 87%, and the total lithium recovery rate reaches more than 94%.

Description

Technical field [0001] The field of chemical industry of the present invention 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 a water-soluble organic solvent as a medium . Background technique [0002] The carbonization-decomposition method to prepare high-purity lithium carbonate is popular for its advantages such as easy operation, no pollution, low cost, stable product quality, and high total lithium recovery rate. This method first uses CO 2 The carbonation is converted into soluble lithium bicarbonate, the ion removal step is carried out, and then heating and decomposition are carried out to obtain a lithium carbonate product. Among them, a key step is the decomposition of the lithium bicarbonate solution, that is, the precipitation of the solid lithium carbonate. The speed and ...

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