New methods for on-line monitoring of flotation to optimize the dosage of surface active reagents

Two difficult and unforeseen problems existing in flotation processes have been the collapse of frothbed and overfrothing. Both of these lead to high losses of floated, valuable minerals. The proper formation of frothbed necessitates suitable surface tension continuously, based mainly on the dosage of frother. The necessity to solve these problems is to develop new measurements for plant use. GTK, the Laboratory of Mineral Processing of GEOLOGICAL SURVEY OF FINLAND, has evaluated new instruments in the market by KSV Instruments, Ltd, to analyze on-line surface tension in industry and laboratory. Simultaneously GTK has developed a novel instrument, frothbed analyzer, to measure and follow phenomena inside frothbed, operated in flotation plant of industrial minerals, too. The surface tension analyzer operated in laboratory, works to confirm the mutual suitability of reagents for new ores tested in the pilot plant of GTK, as well as to evaluate circumstances causing negative effects when dosing reagents in plant. The work continues to evaluate operation of both new measurements in other indus-trial mineral plants and a new challenge is to work in sulphide plants, where the main difference for froth measurement is the higher electric conductivity of minerals.