Effect of the adding order of sulfuric acid on the flotation behaviors of ilmenite and titanaugite and its functional mechanism

The influence of changing the adding order of sulfuric acid (H2SO4) and sodium oleate (NaOL) collector on the flotation of ilmenite and titanaugite was investigated through a series of experiments. Flotation experiments showed that adding NaOL preferentially could improve the ilmenite recovery and reduce the titanaugite recovery, decreasing the H2SO4 dosage in half. Microflotation and ICP analyses indicated that the total ions in pulp caused by the dissolution of H2SO4 prevented the adsorption of NaOL on ilmenite surfaces, but had little effect on titanaugite. However, when adding NaOL firstly, the pre-adsorption of NaOL on ilmenite surfaces weakened the dissolution of H2SO4, while the weak pre-adsorption of NaOL on titanaugite surfaces was destroyed by the dissolution of H2SO4. Thus, altering the adding order of H2SO4 and NaOL could reinforce the adsorption difference of NaOL on ilmenite and titanaugite surfaces, which was evidenced by the contact angle, zeta potential, and AFM analyses.