SYNERGISTIC INTERACTIONS BETWEEN REAGENTS IN SULFIDE FLOTATION

Various reagents are added to flotation pulps to manipulate the chemic al environment in order to create favourable conditions for the separa tion of the desired mineral from the unwanted gangue, Interactions occ ur between these reagents and between the other chemical parameters ex isting in the flotation pulp which complicate the elucidation of the b ehaviour of the respective reagents. This paper discusses the roles of the main classes of reagents added viz. collectors, frothers, depress ants and activators, as well as the interactions between frothers and collectors. A case study reporting synergistic interactions between th iol collectors in the flotation of pyrite at pH = 4 is included. The u se of Potassium n-butyl xanthate (PNBX) and a dithiocarbamate type col lector (DTC) were tested both as pure collectors and as components in a collector mixture. In the batch flotation tests sulphur recovery and grade, water recovery, rate of recovery and image analysis of the sur face froth were used to evaluate the effect of the mixture on the over all flotation performance. Bubble loading tests showed that the use of the mixture improved the efficiency of the particle collection proces s by bubbles. Thermochemical measurements of the adsorption of the col lectors onto the mineral, indicated the formation of different surface products by the two collectors.