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International Journal of Mineral Processing, Vol.54, No.3, 131-145, 1998
The influence of temperature on the kinetics of apatite flotation from magnetite fines
The influence of pulp temperature on the kinetics of apatite flotation from magnetite fines was studied using Atrac (fatty acid type) as collector and sodium silicate as dispersant at pH 8.5-9.0. The batch flotation tests were conducted in a specially designed temperature controlled flotation cell. A modified first-order model, incorporating two rate terms describing fast and slow-floating components, was applied to evaluate the flotation kinetics. The estimation of the model parameters was made by a non-linear least squares fitter program which is based on the Levenberg-Marquardt algorithm. Results indicate that increasing temperature from 10 degrees C to 40 degrees C decreases the phosphorous content in magnetite concentrate but with a simultaneous loss of magnetite recovery. At temperatures below 30 degrees C, an increase in pulp temperature results increasing flotation rate of fast-floating particles and has a marginal effect on slow-floating particles. Above 30 degrees C, the flotation rate of fast-floating particles decreases with increasing pulp temperature. Sodium silicate has a positive effect for increasing the phosphorous recovery and decreasing the phosphorous content in the magnetite concentrate at 20 degrees C for all the levels of collector dosages. In the absence of sodium silicate, collector is active for both apatite and magnetite flotation: The higher selectivity between apatite and magnetite with an acceptable content of phosphorous in the magnetite concentrate is obtained at a moderate dosage of about 400 g/t sodium silicate. The optimum flotation conditions are: 50 g/t collector dosage, 350-400 g/t dispersant dosage, pH 8.5-9 and pulp temperature 25-30 degrees C.
Keywords:FROTH