Experimental Study On Anti-flotation Desiliconization Of Iron Ore With Low-temperature-resistant Collector

With the gradual increase of China's steel consumption,China's steel output can no longer meet China's demand for steel resources.Moreover,domestic iron ore resources are plentiful but poor,more iron ore that is difficult to handle.In some northern iron ore dressing plants,due to the low ambient temperature,in order to maintain the flotation performance of flotation reagents,it is necessary to heat the pulp,which not only increases energy consumption,but also greatly increases the cost of ore dressing.Therefore,the development of high-efficiency low-temperature collectors has important practical significance for improving the economic benefits of mineral processing in China.Based on the research status of iron ore anion reverse flotation process,combined with a series of chemical synthesis process conditions and drug flotation experiments,a new low-temperature-resistant-collector MG-3 was synthesized.The oxidative modification reaction was carried out with vegetable oleic acid as raw material.The oxidative modification condition test and the collector flotation evaluation test showed that the flotation performance of the synthetic collector is roughly proportional to its POV value.The optimal synthesis conditions for the low temperature resistant collector are as follows:the oxidation reaction temperature is controlled at 85±1°C,the oxidation reaction time is controlled at 4.5 h,and the oxidant dosage is controlled.It is 15%of the fatty acid raw material.The pure mineral test shows that the optimum pulp pH is around 11.5,and the MG-3 obtained by oxidation modification has better flotation performance and low temperature resistance than the unmodified fatty acid.Taking the strong magnetic iron ore concentrate of Qidashan Concentrator as test ore sample,the actual mineral flotation condition test was carried out.The experiment showed that the best synthetic raw material for low-temperature-resistant-collector MG-3 was vegetable oleic acid,and its flotation effect was better than the original collector of Anshan Iron and Steel Co.,Ltd.At the same time,the optimal flotation conditions and the best pharmaceutical system were determined:The pulp pH is controlled at around 11.5,the pulp concentration was 40%,the collector MG-3 was 800g/t,and the inhibitor corn starch dosage is 700g/t,the amount of activator lime slurry is 400g/t.Under the optimal flotation conditions and pharmaceutical system,the flotation open circuit and closed circuit test were completed,and excellent flotation indexes were obtained:the concentrate iron grade was 67.84%,and the recovery rate was 89.61%.Infrared spectroscopy indicated that the calcium-activated quartz was chemisorbed with the low-temperature-resistant-collector MG-3.Zeta potential analysis showed that the starch inhibitor can effectively inhibit the adsorption of low temperature collector MG-3 on hematite.When pH?8,Ca²⁺can not effectively activate quartz.At pH>8,Ca²⁺forms Ca?OH?⁺on the surface of quartz,which activates quartz and raises the zeta potential of quartz..The surface of the quartz activated by calcium ions can be adsorbed with the collector ion RCOO^-in the form of a chemical bond,so that the surface is hydrophobic and the floatability is enhanced.Therefore,at higher pH conditions,the separation of quartz and hematite can be effectively achieved by the action of the agents?starch,CaCl₂ and MG-3?.