Research On Mechanism And Application Of Several Kinds Of Modified Starch As Hematite Inhibitor

In this study,the single mineral and actual ore tests、zeta potential、 adsorption capacity and infrared spectrum measurement were conducted to research the mechanism of calcium ion activation in the quartz flotation and starch inhibition of hematite. In order to find a more effective and highly selective inhibitor, the inhibition ability and selectivity of several common starch and modified starch were compared.In the single flotation tests, when the pH is higher than10and the collector is sodium oleate, the oleate calcium is generated by the calcium hydroxide on the quartz surface and the oleic acid ions. And the acid calcium which deposites on the quartz surface bring about the floatability of the quartz increasing.This is the main mechanism of the activation of calcium ions in the quartz flotation.Among three common starch of the corn starch、potato starch and cassava starch, comparatively speaking, the inhibition effect of cassava starch is the better than the other two and the corn starch is next to cassava starch. Comparing the effect of the three modified starch, among enzymatic cassava starch、potassium persulfate oxidated cassava starch and causticizing cassava starch, the inhibition effect of potassium persulfate oxidated cassava starch is the better than the other two. The inhibition effect of causticizing cassava starch is next to the potassium persulfate oxidated cassava starch, but it has shown a good selectivity in inhibiting the hematite. So the causticizing cassava starch could be a better kind of inhibitor in the reverse flotation of hematite.The Zeta potential measurement results have shown that the starch could reduce the Zeta potential of quartz and hematite in the pulp. The drops of the zeta potential on the surface of hematite caused by the causticizing cassava starch are lower than that of quartz. The results of adsorption capacity measurement have shown that the causticizing cassava starch is ape to adsorb on the hematite, so it has a good inhibition effect to the hematite. The infrared spectrum measurement results have shown that, respectively, the causticizing cassava starch adsorption on the hematite is chemisorption and on the quartz via hydrogen bond.The results of actual ore tests have shown that causticizing cassava starch is a good inhibitor in the reverse flotation of hematite.In the closed circuit tests, the grade and recovery of the hematite concentrate could reach62.14%and78.29%on the condition of NaOH,starch,CaO and sodium oleate with the dosage is1.25Kg/t,600g/t,1.2Kg/t and600g/t respectively.