Activating Species

The release of activating species may be accelerated by galvanic interaction. Activation of sulfide species, raising their floatability above that which is achievable naturally, can occur due to an enhancement of the hydrophobicity of the mineral, or due to the insertion or attachment of ions which are more reactive towards collector reagents than the host species. In the latter case, the main, but not only, ion to consider is copper, which may attach itself to a particle as follows, by direct replacement:

The reaction path can be favoured by the presence of a suitable cathodic particulate mineral, like pyrite, reacting along the lines of the following equation:

The effect of galvanic coupling in a conducting particle will cause an electron flow, which will facilitate the simultaneous cathodic reduction of the MS surface by reaction with Cu(OH)2, and the anodic oxidation of MS both reactions producing hydropho-bic surface coverings of Cu2S and S0, respectively.

Another example is the activation of pyrite by lead ions. In support of the assertion that true electrochemical interaction is limited to composite particles, Zhang et al. found, importantly, that interaction between composite particles containing pyrite and sphalerite was negligible in the absence of metal ions in solution. In their presence, sphalerite was found to successfully compete with pyrite for the activating ions, and through their action to compete more successfully for xanthate, thus depressing the floatability of pyrite. Competition for activating species thus seems to be an important factor in the interaction between minerals in flotation.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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