A method for purification of manganese pregnant leach solution
AssigneeMn Energy Limited
InventorMichael John Kitney
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Abstract
Provided is a method for purification of manganese pregnant leach solution (PLS) using solvent extraction (SX). The method broadly comprises the steps of providing a partially purified aqueous pregnant leach solution (PLS), using an SX load stage to form a first organic mixture which forms a loaded organic phase comprising all of the manganese from the PLS, performing two stages of SX scrubbing to form a third organic mixture which is substantially free of impurities, performing SX stripping to transfer the manganese content of the scrubbed organic phase into a clean aqueous phase, and producing high purity manganese sulphate monohydrate (HPMSM) crystals from the clean aqueous phase.
Claims13
A method for purification of manganese pregnant leach solution (PLS) using solvent extraction (SX), the method comprising the steps of:
- providing a partially purified acidic aqueous pregnant leach solution (PLS);
- mixing the acidic aqueous PLS with a fixed volume of organic solvent dissolved in an organic diluent and an alkaline solution for Ph control to form a first organic mixture;
- allowing the first organic mixture to become quiescent for a predetermined amount of time to form a loaded organic phase comprising manganese from the aqueous PLS and a barren aqueous phase or raffinate comprising calcium and magnesium impurities;
- performing SX scrubbing of the loaded organic phase by contacting with a stronger acid solution in water to form a second organic mixture;
- allowing the second organic mixture to become quiescent for a predetermined amount of time to form a first scrubbed organic phase which is substantially free of metal impurities and the barren aqueous phase or raffinate comprising calcium and magnesium impurities;
- performing SX scrubbing of the first scrubbed organic phase by contacting with a weaker acid solution in water to form a third organic mixture;
- allowing the third organic mixture to become quiescent for a predetermined amount of time to form a second scrubbed organic phase which is substantially free of alkaline elements;
- performing SX stripping of the second scrubbed organic phase by mixing with an acid solution in water, wherein the SX stripping transfers the manganese content of the second scrubbed organic phase into a clean aqueous phase;
- and
- producing high purity manganese sulphate monohydrate (HPMSM) crystals by evaporative crystallisation of the clean aqueous phase.
Dependencies are inferred from the claim text.