Study On The Mechanism And Application Of Metal Ions In Cassiterite Flotation System

Abstract:Gravity concentration has long been a preferred method of sorting cassiterites whose brittleness in quality results in a low recovery ratio and a serious waste of resources. Therefore, flotation is the optimum way to make efficient use of tin ore resources. Considering the great impact that pulp environment exerts on the flotation of cassiterites, this thesis probes into the influence of such chemokines as Pb2+、Ca2+、Fe3+and Cu2+on the flotation of cassiterite, calcite and quartz, and then makes a mechanism study of flotation solution chemistry, adsorption density and infrared spectroscopy and so on, arriving at the major conclusions as follows:Benzohydroxamic acid, an excellent collector of cassiterites, can reach as high as80%in recovery ratio on the condition of suitable concentration, temperature, pH and stirring force. However, it turns out to be inferior in collecting calcites with a recovery ratio of only20%and even makes no difference to quartz.Among the four metal ions, Pb2+is the only one that can activate cassitrrites and increase the recovery ratio by5%, whereas the others show a certain degree of inhibition and their respective strengths are for Cu2+>Fe3+>Ca2+; Pb2+is capable of activating calcites and enhancing the recovery ratio from the previous20%to80%while the others can hardly work for calcites. The quartz demonstrates no obvious change in flotation behavior after interacting with four metal ions.The infrared spectrum illustrates that there occurs a certain chemical adsorption between benzohydroxamic acid and cassiterites. The reactions of Pb2+、Fe3+and Cu2+implement the chemisorption in the surface of cassiterites so as to alter the interactive process between cassiterites and chemical agents and give rise to corresponding variations in recovery ratio as well. According to the measurement of adsorption density, Pb2+can boost the adsorption density but the other three reduce it.Actual ore tests manifest that since both magnetite and metallic sulfide ore can inhibit the flotation of cassiterites, the key to the recovery of cassiterites lies in the appropriateiron oxide removal ratio and desulfurization ratio. Closed circuit results were obtained that tin content in tin concentrate is30.18%and recovery is62.44%When tin grade is0.36%in raw ore. Commercial test indicate that flotation is feasible for cassiterite.