Method for preparing lithium carbonate through two-stage conversion of lithium ore

Abstract

The invention discloses a method for preparing lithium carbonate through two-stage conversion of lithium ore and belongs to the technical field of lithium metallurgy. The method comprises the steps: mixing lithium ore powder and concentrated sulfuric acid, performing low-temperature sulfation calcination under condition of 150 to 400 DEG C to convert lithium in the lithium ore into lithium sulfate with good water solubility and meanwhile converting fluorine into hydrogen fluoride gas to be removed to finish first-stage conversion; then performing medium-temperature reduction calcinations on a clinker under 550 to 900 DEG C to convert sulfate of iron, aluminum and the like into aluminum oxide and ferric oxide, which are difficult to dissolve in water, in the clinker to finish second-stage conversion, wherein generated sulfur dioxide flue gas can be used for preparing acid; soaking reduced calcine with water to extract lithium, leaving impurities of iron, aluminum and the like in leaching residues and filtering water-soaked ore pulp to directly obtain a purer lithium sulfate solution. The method not only achieves separation of the lithium from the aluminum and the iron in a leaching process, but also achieves regeneration cycle of sulfuric acid, reduces consumption of chemicals of sulfuric acid, neutralizing alkali and the like and has high lithium recovery rate.

Description

technical field

[0001] The invention belongs to the field of lithium metallurgy, and relates to a method for extracting lithium from ore, in particular to a method for preparing lithium carbonate from lithium ore through two-stage conversion of low-temperature sulfation roasting and medium-temperature reduction roasting. Background technique

[0002] Lithium is mainly used in industrial fields such as atomic reactors, light alloys and batteries, especially for the development of new energy industries such as lithium batteries and nuclear power. Lithium extraction raw materials mainly include lithium ore and salt lake brine. Due to the simple process of extracting lithium from salt lake brine, low energy consumption and low cost, salt lake brine has become the main raw material for lithium salt production abroad. Although my country is rich in salt lake resources, because most of the domestic salt lake brine has the characteristics of high magnesium-lithium ratio, it is diff...

Images