How to Digest Lithium Ores for ICP-OES Analysis

The global market for rechargeable batteries is largely driven by the increasing demand in electric vehicles, grid storage and portable consumer devices, in which Li-ion batteries are the preferred option so far.
The demand for high-quality lithium (battery grade) explodes and makes the exploration and development of lithium ore deposits extremely attractive. In addition to lithium salt extraction from brine, following lithium minerals are mined on a large scale:
Spodumene is a pyroxene mineral consisting of lithium aluminum inosilicate (LiAlSi2O6). It is the most widely exploited mineral source of lithium (theoretical lithium content = 3.73 %). Other lithium-bearing pegmatite silicates include lepidolite and petalite.
Since production requirements are becoming more stringent for Li-ion battery manufacturers, it is important to determine the exact and consistent element composition of the raw materials. Furthermore, there is a large demand for fast routine analysis in the mining industry. In prospecting for new mining projects or in developing and maintaining existing mines, large numbers of mineral samples have to be quickly analyzed.
Especially for oxides of silica, aluminum and many of their variations or mixtures, digestion with varying mixtures of sulfuric, hydrofluoric and hydrochloric acid is a requirement, in many cases with a subsequent complexation step with boric acid. Not surprisingly, this leads to numerous possible hardly soluble precipitates.
The Anton Paar microwave digestion system Multiwave 5000 with Rotor 20SVT50 can quickly reach higher digestion temperatures up to 250 °C and maintain them over an extended period of time. As a result, excellent quality of digestion even for hard to digest samples can be achieved.
With up to 20 samples in one single run, Rotor 20SVT50 offers unrivaled efficiency. The convenient tool-free handling and the compact vessel design to ease weighing, cleaning and operation make Rotor 20SVT50 the ideal candidate for demanding samples in Multiwave 5000.
The method described in the following suits for the Lithium ore samples being studied. However, depending on the source of the samples, their composition may vary and require some modifications e.g. to the acid mixture. In any case, it may be used as a starting point.