Development and optimization of a modified process for producing the battery grade LiOH: Optimization of energy and water consumption

Abstract

LiOH center dot H2O is used for preparation of alkaline batteries. The required characteristics of this compound are low levels of impurities and a specific particle size distribution. LiOH.H2O is produced from ore and brines. In northern Chile, lithium is produced from brines. This region presents particular desert climate conditions where water and energy are scarce. To help solve this problem, the conventional production process for battery grade LiOH center dot H2O was simulated and a modified process was developed, with an efficient consumption of energy and water, to improve the environmental sustainability of the plant, and greater process yield and product purity.

Different configurations of the equipments were studied and for the best configurations the behavior of the modified process at different scenarios were simulated.

It was found that the purity is independent of concentration used in feed to thickeners. The process yield increases in average 2.4% for modified process due to recycling operation. In modified process is obtained 28% more product mass, specific energy consumption decreases up to 4.8% and losses of Li/kg of product decreased by 83% compared to conventional process. The water consumption per kg of product in modified process is 1%-63%, being lower than in conventional process. The results presented can be considered as guidelines to address the optimization of the industrial process for obtaining the battery grade LiOH.