The Interaction Mechanism Of Metallic Ions In The Flotation System Of Wolframite

Wolframite slime, being characterized as high yield, high grade, high content of metal,etc, has long been a challenge for researchers of mineral processing to recover tungsten from the slime effectively and efficiently. The concentrate recovery is commonly below45%when gravity separation is adopted, While the key to conduct flotation separation technology is to select highly selective and effective collectors and activators. The author chose benzohydroxamic acid, a new chelant used in many oxide-mineral processing plant, as collector, and the interaction mechanism of metallic ions, such as Pb2+, Fe3+, Fe2+, Mn2+, Ca2+, Mg2+, Cu2+, Zn2+, Al2+, in the flotation system of wolframite-benzohydroxamic acid-metallic ions has been studied in order to find special metallic ion that can be used as activator and fully understand acitivation mechanism of metallic ions in flotation system of wolframite.The effect of cations like Fe2+, Fe3+, Mn2+, Cu2+, Zn2+, Al3+, Ca2+, Mg2+on floatability and surface wettability of wolframite with BHA as collector is unconspicuous, only Pb2+can promote the flotability and surface wettability of wolframite obviously; when amount of Pb2+is added properly concentrate recovery and floatation increased positively, but excessive amounts of Pb2+can cause deterioration in floation;The active adsorption species of Pb2+is variable in the premium floatation pH range of wolframite(pH6-10), in lower pH solution PbOH+is the main activating component, while in higher pH pulp the activation mechanism can be explained by adsorption of surface lead hydroxide sediment respectively;Pb2+can facilitate the adsorption of BHA onto surface of wolframite. The adsorption isotherms obey Freundlich equation when Pb2+is introduced; the activating component of Pb2+can change the chemistry environment of Mn proton on the surface of wolframite, thus the Mn proton possess great chemical activity and become the main activation proton, which chelates with benzohydroxamic acid and forms hydroxamate salts.