Flotation of quartz from a mixture with fine hematite using dodecyltrimethylammonium bromide (DTAB)

Separation of fine quartz (-10 μm) from a mixed suspension (1:1 by weight) with fine hematite (-10 μm) was investigated by means of desilicification flotation using dodecyltrimethylammonium bromide (DTAB). Measurement of the coagulation and dispersion of suspensions of quartz and hematite was also carried out, and heterocoagulation theory was applied to analyze the flotation results. The results are summarized as follows: (1) in acidic solution (pH 5), it was difficult to separate quartz from the mixture due to the heterocoagulation between both mineral particles, (2) in alkaline solution (pH 10), selective flotation of quartz was also difficult because of concurrent flotation of hematite, and (3) fairly good results were obtained at pH 7 - 8, where the heterocoagulation between quartz and hematite is prevented and the adsorption of dodecylammonium cations in excess amount onto hematite surfaces is avoided.