ZINC CONCENTRATE OPTIMIZATION
OBJECTIVE.
Improve the grade of zinc concentrate using nitrogen as flotation gas for eliminating iron from pyrite and reduce part of copper from chalcopyrite. It is known that many times zinc assay in Pb-Cu-Zn ores treated in concentrator plant does not have high values, getting dirty zinc concentrates with copper values higher than 5% and iron values between 5 to 15%, resulting in a zinc concentrate with values less than 50%.
INTRODUCTION.
Use of gases other than air in industrial froth flotation has been reported from time to time [1]. Of all the gases, nitrogen would appear to hold the greatest practical promise because of its ready availability and chemical inertness. It is used now in chalcopyrite – molybdenite separation. The use of nitrogen in this case is mainly to reduce the oxidation of NaHS, reagent used as a depressant for chalcopyrite.
From the metallurgical standpoint nitrogen has two effects of interest. Firstly, it lowers the activity of oxygen in the pulp and, as a consequence, reduces the pulp potential. Both effects should influence the selective flotation of sulphides. It has been reported that xanthate-pyrite interaction requires the pulp potential to be higher than 200 mV (vs. Standard Hydrogen Electrode, SHE). Thus, oxygen plays a direct role in xanthate adsorption.
The reduce activity of oxygen may influence galvanic interactions between Sulphide minerals. In studies on galvanic interactions have been showed that pyrite draws electrons from other contacting Sulphide minerals [2]. The resultant lowering of the combination potential reduces the flotation of pyrite. The presence of oxygen appears to be essential in this galvanic coupling, the oxygen acting as an electron acceptor probably reacting with the transferred electron to form OH-. The use of nitrogen would interrupt this galvanic reaction.
From a practical viewpoint nitrogen is easy to produce (90-95% purity). It is unlikely to be consumed by chemical reactions since it is inert and poorly soluble in water.
Mining Glossary A Assay Salting Bismuth Elements, Alloys and Symbols Crusher Operating Cost Anglesite Composition, Crystallization & Structure Proustite - Light Ruby Silver Composition, Crystallization and Structure Results in laboratory test and pilot level with Cu-Pb-Zn polymetallic ores. Metasilicates – Leucite Composition, Crystallization & Structure Mineralogical Properties of Molybdenum Minerals. AKA Moly Molybdenite Jadeite and Wollastite Composition, Crystallization & Structure Iolite Cordierite Composition, Crystallization & Structure Mineralogy Manual Types of Rock Crushers The Mining Team Mining Glossary C
