Measurements were also taken on a third process stream, rougher concentrate, over portions of the investigation period. Because of the low percent solids in sample flow streams, the accuracy of rougher concentrate BPL measurement was inadequate for practical use in the investigation. This deficiency could have been overcome by further development of sample presentation, but feed and tails data provided sufficient data to demonstrate the utility of the method. Plant A operates by manual settings of control devices such as feed and reagent flows. Plant B employs a central supervisory control system.
Plant operation is stabilized and logged with a printer using regulatory control loops.
Control at plant B is maintained by the supervisory system from settings provided at a control console by plant operators. Results of statistical evaluation during continuous routine operation indicated substantially greater loss of product using manual control in plant A as compared to plant B using the central supervisory control system. Inefficiencies were observed in both plants, though to a lesser extent in plant B with its central control system. Analysis of the data indicate that gains in productivity of two to four percent are possible with application of stabilizing and other advanced methods of process control. The statistical treatment of data is described in the original proposal for this investigation.