Separation of Molybdenite from Chalcopyrite

Flotation of minerals by use of nitrogen is commonly applied in the separation of molybdenite form chalcopyrite. The predominant scheme is to depress the copper sulphide while capitalizing on the ready floatability of molybdenite to effect the separation [15]. In order to carry out differential flotation it is necessary to depress the copper sulphide by adding a depressant such as sodium sulphide or sodium hydrosulphide. Chal

copyrite can reduce its floatability when the Redox potential takes a value above about -250 mV (calomel electrode). The optimum value is in the range -450 mV to -500 mV. Air addition results in the oxidation of the sulphide ion to less effective polythionates. See Figures 3 and 4.

Fig. 3 Percentage of the copper content of the pulp that is depressed (taken from [16])

Fig. 4 Relationship between the copper depressed and mV of flotation pulp (taken from [16])

Also, CO2 can be used to control the froth texture through pH modification (See Figure 5, from author’s collection). If pH is very low (< 8.5), H2S will be released. Molybdenite is usually hydrophobic, but a little fuel oil may be required.

Section of an Exploratory Pit with Timber Wood Stoping Methods of Mining Magmatic Deposits Ratio of Reduction Iron Composition, Crystallization, Structure and Occurrence Conditioning for Flotation IMPLEMENT Pyrite flotation tests with nitrogen Sizing and Selecting Shovel and Crusher Sizes Replacement Deposits Feed Undersize and crusher capacity Magic - Pectolite Composition, Crystallization & Structure Mineralogical properties of galena and some bismuth minerals. Lode Deposits Gahnite Composition, Crystallization & Structure