Biological leaching of low-grade nickel laterite ore is based
on a non-traditional leaching of oxide minerals using heterotrophic
or fungi microorganisms including Aspergillus and
Penicillium strains and their metabolic products (organic acids).
In this process, organic acids produced by the metabolism of
the fungi organisms, solubilise metals from oxide minerals to
form metal organic complexes [1]. Among the various organic
acids produced, citric, malic and lactic acids have been found the
most effective in dissolving the desired metals (Ni and Co) from
low-grade nickel laterite ores [2]. Although the amenability of
nickel laterite to this bioleaching process has been demonstrated,
studies of Ni and Co recovery from the resulting metal-organic
complexes appear scarce.
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