Basically, a column flotation cell produces all of the gold concentrate at the concentrator. For this reason it is very important for the column cells to operate at maximum efficiency. Throughout the shift, the column cells must be inspected for potential problems. There should be a maximum interval of 30 minutes between inspections at the upper operating level. Once each shift, make a careful inspection of the mechanical condition of the cells, Check for leakage at flanges, overflow launders, feed pipes, and tails pipes, observe the washwater main line piping system for leaks or broken brackets, check the sparger gas main line piping system for leaks or broken brackets, Check the sparger inlet pressure (make sure it is properly set).
It is important to observe the appearance and condition of the froth, the column cell washwater distribution system, the drip pan to ensure that the holes are not plugged. Clear if necessary, ensure that there is the sufficient launder water in use to break down the froth and move the slurry down the launder, check the launder spray bars to ensure that the holes are not plugged. Check the final gold concentrate assay. If the concentrate is substantially below target grade, the column cell air flow must be reduced to reduce the flow of froth and produce a higher concentrate grade. If changing the gas flow has no effect, decrease the level and increase the washwater flow rates to try to improve the grade.
Also, the flotation operator must review the condition of the cleaner feed distributor, the dart isolation valves in the distributor feed lines for slurry leaks, the valve actuators for damage or unusual wear. Make sure the valves are fully open for the columns scheduled to operate and fully closed for columns that are not in service. Check around the base of the column cell, ensure the tailings line isolation valve is completely open, ensure the tailings line drain valve is closed, ensure the fluidizing water valves are closed, and check the level control valve. Ensure there are no air or slurry leaks, and no evidence of mechanical damage to the valve.
Column Flotation Cells