Over a four-hour period of steady plant operation samples were taken at regular intervals from points within the grinding and flotation circuits._x000D_
Size fractions of each composite sample were analysed for lead and zinc values and a comparison made of the behaviour of the lead, zinc and gangue minerals, size by size throughout the whole circuit. Analysis of the breakage behaviour using dynamic mathematical models gave the rates of breakage of each size fraction of each main component._x000D_
Simulated grinding experiments showed that the main grinding circuit had sane reserve capacity. In the lead flotation circuit all lead values between 150 mesh (Tyler) and 5 microns had excellent flotation characteristics, and a major proportion had a high rate of flotation which was practically the same for all sizes. Increase in overall lead recovery would require improvement of the flotation behaviour of ultra-fine lead minerals._x000D_
These were slow floating and were responsible for approximately half the lead losses in the final zinc concentrate and one third of the lead losses in the final tails.