Dissolution of Manganese from Polymetallic Material Using Sulfuric-Oxalic Acid Medium

Abstract

Sedimentary rocks have been found to host several Mn minerals in addition to some economic metal values. Besides recoverable Al occurring as gibbsite mineral, the latter include Cu, Zn, Co, Ni, U as well as rare earth elements. In this work, the ore material was subjected to sulfuric acid leaching in the presence of oxalic acid as a reductant to maximize the extraction of Mn. The optimum leaching conditions to achieve almost complete leaching efficiency of Mn with Fe dissolution not exceeding 13% involved 0.5 M sulfuric acid and 0.25 M oxalic acid in a solid/liquid ratio of 1/15 at 85˚C for 105 min using an ore size of −150 μm. The leaching behavior of the associated interesting metal values (Al, Cu and Zn) has also been investigated.

Metal Recovery Using Oxalate Chemistry: A Technical Review

“…Under optimum conditions, 93.4 wt% Mn and 15.8 wt% Fe can be leached using 0.7 M sulfuric acid and 0.5 M oxalic acid for 1 h at 63 °C. Hazek et al performed a similar study as Sahoo et al on a polymetallic Mn ore and leached 98 wt% Mn, 94 wt% Zn, and 92 wt% Cu using the optimum conditions for sulfuric acid leaching with oxalic acid as a reductant. These studies prove that the addition of sulfuric acid can improve the leaching efficiency for Mn.…”

Overview on the removal of iron from phosphoric acid: A Comparative study

“…On the other hand, oxalic acid exists in solution in many species ( Most oxalate compounds are insoluble in water, thus act as a precipitating agent for alkaline earth metals, transition elements and rare Earth elements [39,40]. The excess of oxalate may form various soluble oxalate complexes that find numerous applications in the leaching processes for the removal of iron from illmenite [41], nickel from Greek laterite ore [42], manganese and tungsten from their ores [43,44].…”