Preparation of high-purity manganese sulfate and removal of unwanted metal ions using resin-based purification

High purity manganese sulfate(MnSO4) is of great importance due to its applications in lithium-ion batteries, pharmaceutical applications, and within feed additives. As manganese always occurs in combination with iron, laterite and other minerals, co-leaching of Mn and Fe complicates the purification procedure of MnSO4. Obtaining high purity MnSO4 without contamination of calcium and magnesium is difficult, because of their similar chemical properties. Current research involved preparation of highly pure MnSO4 from low purity MnO2. A simple and efficient procedure has been developed for purification of MnSO4 by using a carbon adsorbent followed by treatment with iminodiacetate functionalised resin polymer. The two-step procedure enabled an extremely pure MnSO4 generally exceeding 99.9%. Iron has been efficiently removed to below 5 ppm (>99% reduction from similar to 1000 ppm), calcium was reduced to similar to 100 ppm (>90% reduction from similar to 1600 ppm) and magnesium was reduced to below 10 ppm (>99% reduction from similar to 1400 ppm). Adiitionally, simple carbon adsorption effectively reduced lead and zinc to below their detection levels (< 0.050 and 5.00 ppm, respectively) and arsenic was reduced to below its level of quantification (< 0.375 ppm). Careful adaptation of the procedure allows for producing high purity manganese salts at a larger scale.