Conversion of Spodumene to Lithium ChemicalsToday, lithium...

Conversion of Spodumene to Lithium Chemicals

Today, lithium minerals are actively mined from pegmatite hard rocks.Worldwide, numerous deposits, primarily containing spodumene and petalite, are being intensively explored with several at an advanced stage in Canada, Finland and Australia. Beneficiated lithium minerals are used in
the mineral form and for chemical conversion to lithium carbonate.Spodumene (8.0% Li2O), is the most common commercially exploited
lithium mineral.

Almost 50 % of the spodumene mined in Australia today is converted to lithium carbonate in China.

Input material requirements Spodumene used for the extraction of lithium carbonate should be a concentrate with at least 6 % Li2O (75 % Spodumene).

As calcination of spodumene is the major cost driver during lithium carbonate production, the efficiency of this process step needs to be considered compared with the specific cost of Li2O in the concentrate.

Calcination
Calcination is a prerequisite for the leaching step, as only less than 1 % of the lithium contained in alpha spodumene will be extracted without
prior transformation into beta-spodumene.The transformation of alpha to beta-spodumene takes place between 1,050 °C and 1,100 °C. During the transformation decrepitation of alpha spodumene occurs, resulting in a volume increase of 20 % (Fig. 3). The conditions of calcination need to be adjusted to the composition of the ore. At temperatures above 1,150 °C some ores begin to fuse and trap lithium in the insoluble glass phase.