Method for preparing lithium hydroxide monohydrate by using lithium carbonate

The invention relates to a method for preparing lithium hydroxide monohydrate by using lithium carbonate. The method comprises the steps: adopting industrial grade lithium carbonate as a raw material,performing a reaction on suspension of the lithium carbonate, calcium oxide and water under the conditions of heating, pressurizing and stirring for 90-110 min, and performing filtration, purification, elution crystallization, drying and the like so as to obtain lithium hydroxide monohydrate. The method has the advantages that industrialization can be realized easily through adoption of industrial grade lithium carbonate to prepare the lithium hydroxide monohydrate, and improvement of the reaction speed and shortening of the reaction time are achieved by adopting a pressurized mode to increase the reaction temperature, so that the conversion rate of lithium carbonate is achieved; by adopting the elution crystallization method, the problems that a previously adopted evaporative crystallization method has large ene