US 12,434,973 B2
Graphite material purification process
Duncan Turner, Buderim (AU)
Assigned to TALGA TECHNOLOGIES LIMITED, Cambridge (GB)
Filed by Talga Technologies Limited, Histon (GB)
Filed on Dec. 19, 2024, as Appl. No. 18/988,116.
Application 18/988,116 is a continuation of application No. PCT/IB2023/056656, filed on Jun. 28, 2023.
Claims priority of application No. 2022901820 (AU), filed on Jun. 29, 2022.
Prior Publication US 2025/0128952 A1, Apr. 24, 2025
Int. Cl. C01B 32/215 (2017.01); B01D 11/02 (2006.01)
CPC C01B 32/215 (2017.08) [B01D 11/0288 (2013.01); C01P 2006/12 (2013.01); C01P 2006/40 (2013.01); C01P 2006/80 (2013.01)] 29 Claims
OG exemplary drawing
 
1. A graphite material purification process, the process comprising the steps of:
(i) Passing a concentrate of the graphite material to be purified to a pelletisation step providing a pelletised material;
(ii) Baking the pelletised material of step (i) in caustic conditions providing a sintered product and whereby one or more impurity minerals are rendered soluble;
(iii) Passing the sintered product of step (ii) to a water leach step whereby at least a portion of the impurity minerals from step (ii) are solubilised, forwarded for effluent treatment, and separated from leach solids;
(iv) Passing the leach solids of step (iii) to a first sulphuric acid leach step wherein impurity minerals partially leached in step (iii) are solubilised, forwarded for effluent treatment, and separated from leach solids;
(v) Passing the leach solids of step (iv) to a hydrofluoric acid leach step, wherein partially leached impurity minerals are solubilised, forwarded for effluent treatment, and separated from leach solids;
(vi) Passing the leach solids of step (v) to a second sulphuric acid leach step wherein impurity minerals or components precipitated during step (v) not leached in previous steps are solubilised, forwarded for effluent treatment, and separated from leach solids; and
(vii) Passing the leach solids of step (vi) to one or more washing stages wherein at least a portion of any remaining soluble impurities are separated, and whereby a purified graphite material is produced.