Continued development of copper flotation control at the Kidd Creek concentrator

"Automatic flotation control in varying degrees of sophistication is practiced at a number of concentrators throughout the world. Practically, the variable conditions in the flotation circuit and the difficulty in maintaining accurate instrumentation information all add to the complexity of automatic control.Further development at the Kidd Creek concentrator has resulted in a 3075 mtpd copper flotation circuit capable of running twenty-four hours a day under the direct control of an optimizing supervisory computer.Three main streams, continuously monitored by an XRF analyzer, supply circuit information to the optimizing computer. Circuit efficiency calculations (from smelter contract terms) and target setpoints allow the computer to determine the economic optimum direction to move the circuit based on the grade/recovery relationship. Circuit manipulation is accomplished by precise pumping of collector and frother reagents together with accurate control of flotation bank pulp levels. The former uses computer controlled diaphragm pumps and the latter is achieved by control loops utilizing a float type level transmitter, variable position dart plugs and a process computer working to setpoints determined by the optimizing computer.The development of a fully automated flotation circuit is by no means complete, but increased knowledge and major hardware improvements have allowed its progression to a higher level of sophistication.IntroductionThe Kidd Creek concentrator is located twenty-six kilometers east of Timmins, Ontario, within a metallurgical complex including a 109,000 mtpy zinc plant and a 59,000 mtpy copper smelter and refinery. The concentrator treats two ore types, a copper-zinc ore and a copper-silver-Iead-zinc ore, at a combined rate of 4,500,000 mtpy. Flotation of the crushed and ground ore yields copper and zinc concentrates from the copper-zinc ore and copper, lead and zinc concentrates from the copper-silver-lead-zinc ore."