Abstract
Ph.D. (Chemistry)
The effect of crystal defects on the adsorption and flotation
properties of zinc sulphides was examined. Flotation experiments
were restricted to collectorless flotation, that is to the flotation
of untreated and copper-activated samples. The effect of cyanide
treatment was examined only so that an explanation could be found
for the bonding characteristics of the adsorbed copper on regions
where the crystallography was undisturbed and on those where it
was distorted.
The electrochemical method for the determination of copper
permitted continuous and highly sensitive monitoring of the copper
adsorption on the sphalerites.
The first part of the thesis concerns the adsorption of
copper on synthetic zinc sulphide crystals and natural sphalerites.
It is stated that the degree of adsorption depends on the defect
structure. Structure etching, gamma-ray irradiation, and selective
grinding experiments are shown to justify the conclusions reached.
The second part of the thesis describes the flotation of the
samples. The adsorption characteristics of the samples are defined
in the first part and the adsorption and flotation properties are
correlated.