Abstract:
BACKGROUNDThe transition metals copper, cobalt, nickel, zinc, lead and the noble metal elements (the platinum family elements gold, and silver) are highly enriched in sulfide minerals, especially in magmatic sulfides. Sulfides commonly form large ore deposits of industrial significance, which makes sulfide minerals of great economic value. There are many kinds of sulfide ores, and the contents of Ag, Cu, Pb and Zn in different types of sulfide ores vary. Some sulfide ores cannot be decomposed completely by strong acid and therefore precipitation forms, resulting in large errors and low precision.
OBJECTIVESInvestigate different digestion conditions in order to decompose, dissolved sulfide ores containing pyrite, galena and chalcopyrite.
METHODSThe sulfide ores are reacted with hydrochloric acid to remove the sulfur, and then digested by HNO3-HF-HClO4. Newly prepared aqua regia is used to further dissolve metals. The contents of silver, copper, lead and zinc in sulfide ores are determined by Flame Atomic Absorption Spectrometry (FAAS) and Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES).
RESULTSThe results show that sulfide ores can be decomposed ideally using the proposed procedure, especially for sulfide ores with high contents of silver and lead. The contents of silver, copper, lead and zinc in sulfide ores can be determined accurately by both FAAS and ICP-OES with a relative error of two methods of less than ±2.32%. The measured values are the same with the relative standard deviation(RSD, n=12) less than 3.5%. The detection limit of the four elements is below 0.0090 μg/mL, lower than current published values.
CONCLUSIONSThis method can be used to obtain an ideal decomposition effect, especially for high content silver and lead sulfide ore samples.