| The lack of iron resources in China has become an outstanding and urgent problem after years of mining, which seriously affects the rapid development of Chinese economy. However, the requirement of higher pulp temperature to maintain the activity of fatty acid anionic collectors which have been widely applied in technological process of iron ores reverse flotation led to a great deal of energy consumption. Therefore, application of a new type of collector at room temperature could make a great significant difference.The components and characters of mixed concentrate of magnetic separation from Sijiaying plant were studied by using X-ray fluorescence (XRF), X-ray diffraction (XRD), chemical and physical analyses, particle size distribution and TFe content of all grain levels. Results of chemical analysis shown the useful element was ferrum, while the main impurity elements were silicon, aluminum, and magnesium etc. Analyzing of XRD spectrum, we found that the main iron minerals were hematite, limonite, magnetite, and a few cyclonite, while quartz, dolomite, chlorite were the essential gangue minerals in ores. Through screening tests of magnetic concentrate, about 77.12% Fe occurred in finely disseminated ores which the yield accounted for 59.44% when the grain diameters were under 0.038mm. Based on known results, the synthesis and optimization of a new type of collector at room temperature was realized. Moreover, tests of single mineral flotation, direct and reverse artificial mixed minerals flotation, actual ores flotation, open-circuit and closed-circuit flotation were carried out to detect the performance of DLW type collector.Test results of single minerals flotation shown that through optimum conditions of pulp pH 11.50, dosage of activator CaCl2 250.00mg/L, DLW dosage 250.00mg/L, we obtained maximum quartz recovery of 89.33%, while pulp pH 9.00, collector DLW dosages of 125.00mg/L and 250.00mg/L for hematite, magnetite, the recovery values of 93.71%,96.33% were received respectively at 16?.The direct and reverse flotation tests of artificial mixed minerals were conducted on the basis of single minerals flotation. Through direct flotation, the grade and recovery of concentrate have reached to 66.54%, and 97.66% when pulp pH 11.50, dosage of CaCl2 250.00mg/L, while, under the conditions of depressor starch dosage 6.00mg/L, CaCl2 dosage 250.00mg/L, DLW dosage 312.50mg/L, the concentrate grade of 66.68% and recovery of 96.87% have been gained finally. Comparing the experimental results between the direct and reverse flotation, DLW type collector has been proved to be a preferable separation reagent no matter which kind of flotation technology was applied.The condition experiments, open-circuit flotation experiment, and closed-circuit flotation experiment were accomplished. When conditions meet requirements that including pulp temperature 25?, density 45%, pulp pH 11.50, starch dosage 800g/t, CaO dosage 750g/t, roughing DLW dosage 700g/t, cleaning collector dosage 400g/t, through the reverse flotation experiment of one roughing-one cleaning-one scavenging obtained the concentration grade of 64.65%, Fe recovery of 77.79%, while the grade of tailing was 15.89%. The experiment demonstrates that DLW is an effective flotation collector on Sijiaying refractory ores.By means of modern detecting technology such as Fourier transform infrared spectroscope and ?-potential measurement, combining the results of single mineral flotation, and the basic theories of flotation solution chemistry, surface chemistry, and crystal chemistry etc., the absorption type between mineral and collector has been analyzed. The research shows that on the surface of hematite and magnetite chemical absorption and hydrogen bond absorption take the dominant position, while the main absorption is electrostatic force on quartz's surface. |
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