| Tianium resource is rich in China, mainly occurs as vanadium-titanium magnetite. The feed of ilmenite separation is commonly the tailing from the beneficiating of vanadium-titanium magnetite and the mian separation technology is magnetic separation followed by floatation, and the recovery of ilmenite is less than 30% because of the lose of a large amount of fine ilmenite in the tailing. The cause of losing is still unknown for us. For this, the paper studied the separation feathers of different fractions of ilmenite especially the fine ilmenite. At the same time, the separation feathers of titanaugite and the influence of it on the separation of ilmenite were also studied. On the basis of experimental research, combining theoretical calculation and analysis, the reasons of low recovery of ilmenite were discussed.The magnetism of different fractions of ilmenite and titanaugite were analysed by using magnetic balance and vibrating sample magnetometer. The results showed that the specific susceptibility of the fine ilmenite was low, and there was little difference between the fine and the coarse; that the specific susceptibility of the fine titanaugite was lower than that of the coarse; and that the specific magnetization of each fraction of ilmenite and titanaugite increased sharply firstly and then slowly with the increase of magnetic field intensity. Separation experiments for different fractions of ilmenite and titanaugite were done using XCSQ magnetic separator. The results showed that under different magnetic fileds the lower the size of ilmenite and titanaugite, the lower was the recovery of them; and that high recovery can be received under low intensity for the coarse, but the recovery was low even under high intensity for the fine.By flotation experiments of pure minerals, the effects of reagent conditions such as the dosage of collector and depressant, collector effecting time, pulp pH, and operating factors such as pulp mixing speed, flotation time on the recovery of titanaugite were studied. The results showed that each fraction of ilmenite had a good flotability at pH 4-9. The finer of ilmenite particle size, the greater the best dosage of collector, the longer the best collector effecting time, the higher the mixing speed, the longer the best flotation time. Sodium silicate had a little impact on the flotability of ilmenite. All fractions of titanaugite had a good flotability at pH 5.5～7.5. The recoveries of each fraction titanaugite incraesed with the increase of collector dosage. The depressing of sodium silicate on coarse titanaugite was stronger than that of sodium silicate on fine titanaugite.By flotation experiments of mixed minerals, the effects of different fractions titanaugite on separating of ilmenite of each size fraction were studied. In the process of magnetic separation for mixed minerals, coarse titanaugite had apparent influence on ilmenite, which was reflected from the fact that the content of ilmenite in magnetic concentrate was reduced and the recovery of ilmenite changed little. In the process of floating separation for mixed minerals, it is fine titanaugite that had greater influence on ilmenite. The recovery of ilmenite was improved, while the content of ilmenite in flotation concentrate was seriously influenced. The difference of floatability between ilmenite and titanaugite was small.On the basis of experimental results, reasons for low recovery of fine ilmenite were calculated and analyzed combining force analysis which ilmenite born in separating area of magnetic separator and the theory of fluid dynamics and flotation kinetics. The analysis results showed that the medium resistance of fine ilmenite of was larger than that of coarse ilmenite in the process of magnetic separation, and that the recovery of fine ilmenite needed high magnetic force. The main restrictive factor was the low collision probability between fine ilmenite and bubble in flotation.The results of this study provided a theoretical basis for improving the separation of fine ilmenite. |
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