| Two major problems should be solved in order to achieve high-sulfur bauxite industrial utilization. The first problem is how to remove S in an efficient way, which consists two aspects:(1) trying to reduce the S content of concentrate to 0.3%, (2) reducing diaspore entrainment effectively. The second problem is how to remove Si from diaspore effectively. Pure mineral experiments, Voltammogram, adsorption method were used to analyze activated desulfurization theory, and pure mineral experiments, Zeta-potential, SEM, Fluent simulation were used to analyze the theory of reducing diaspore entrainment.The theory of removing S with activation ways shows:(1) Cu2+ is the best metal ion to activate pyrite. CuS and element S were found to appear through Voltammogram, which promoted the collection ability of butyl xanthate to pyrite. (2) The adsorption result of butyl xanthate to pyrite presented a high increase of adsorption after the addition of Cu2+ which strengthened the hydrophobicity of pyrite.The theory of reducing diaspore entrainment shows:(1) large rotation speed and small particle size could promote diaspore entrainment. Moreover, pH value and the dosage of collector and forther were able to affect the bubble quality, resulting in different entrainment. (2) Pure experiment results showed that modified starch is an efficient macromolecule reagent. Zeta potential, FTIR spectra and adsorption analysis showed static force, hydrogen bond between modified starch and diaspore. What is more, SEM images presented the flocculation of diaspore in the presence of starch, which increased the particle size of diaspore, and then reducing entrainment. (3) CFD simulation showed:the increase of particle size, input velocity of mixture or rotation speed would cause the volume fraction of the diaspore to reduce and affect the turbulence intensity and velocity of the mixture in the flume of the flotation cell, resulting in different entrainment results. The simulation results corresponded well to the flotation experiments.The desulfurization flotation experiments results of high-sulfur bauxite ore showed:the high-sulfur tailing with 10.5% S grade and 72.40% S recovery as well as low-sulfur concentrate with 0.28% S grade and 93.47% Al2O3 recovery was achieved with oxalic and copper sulfate as activators, with modified starch as depressant to reduce entrainment. |
