| Abstract
| - Due to its environmental consequences, acid minedrainage (AMD) has been recognized as a major challengeto the global mining industry. Through the innovative useof magnetic seeds, a versatile ambient temperature ferrite(ATF) process has been developed to treat AMDscontaining such nonferrous heavy metal ions as Cu2+,Zn2+, Ni2+, Mn2+, and Al3+. These metal ions proveddetrimental to ferrite formation using the existing ATFprocess, particulary when lime was used as neutralizer.The use of magnetic seeds in the ATF process minimizedthe interference. The role of the chemical environmentin ferrite formation from an AMD with the addition of magneticseeds was investigated. Compared with the conventionalseed processes, controlling the solution chemistry resultedin a reduced amount of seed needed to recover anequal amount of crystalline magnetic precipitates. With arelatively short processing period (less than 2.5 h), upto 100% of the precipitates were magnetically recoveredfrom a simulated AMD. The residual concentrations of majorcontaminant ions in the treated water were below thecorresponding acceptable levels. The XRD pattern showedthat the solid products were all of spinel ferrite crystalstructure, in contrast to the presence of a substantial amountof noncrystalline phase in the product formed using aconventional seed process.
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