新型摩擦电选机的开发及磷矿电选试验研究

发布时间：2018-11-18 17:45

【摘要】：摩擦电选是一种效率高、污染少、不耗水的干法选矿技术,在全球水资源贫乏和污染日趋严峻的形势下,越来越受人们关注。摩擦电选机是实现摩擦电选的关键,经过多年发展,国内外已经开发了多种摩擦电选机,但仍存在带电量少、荷电不充分、处理能力小、易磨损或矿粒粘附等问题。我国是个磷矿资源大国,但大部分为中低品位磷矿,需要经选矿提高品位或去除杂质才能成为合格精矿,目前普遍使用的浮选法存在成本高、污染大等问题,亟待改进。论文结合中低品位磷矿资源选矿需求开发新型摩擦电选机,具有重要的理论意义和实用价值。在分析矿物摩擦电选机理的基础上,确定新型摩擦电选机以气流输送矿粒。摩擦荷电器是摩擦电选机最核心的部分,首先研制出冲击式摩擦荷电器、斜板式摩擦荷电器和锯齿波式摩擦荷电器三种新型气流摩擦荷电器。选取磷灰石和石英纯矿物进行了摩擦荷电试验研究,结果表明:三种摩擦荷电器内,磷灰石和石英都能够荷电,且磷灰石带正电、石英带负电;相同摩擦荷电器内,磷灰石和石英的摩擦荷电规律一致,而不同摩擦荷电器内,各粒级磷灰石或石英随干燥温度的变化规律相似;冲击式摩擦荷电器在高气流速度时的荷电效果较好,斜板式摩擦荷电器的优势则表现在低气流速度范围,而锯齿波式摩擦荷电器在高气流速度时才能达到较好的荷电效果,但仍然不如冲击式和斜板式两种摩擦荷电器;冲击式摩擦荷电器的最佳荷质比最大,但单位体积荷质比小,内部空间利用率有待提高;斜板式摩擦荷电器的单位体积荷质比大,内部空间利用率高;锯齿波式摩擦荷电器的内表面积和内部摩擦板面积都较大,但单位体积荷质比不大、给料量也较小,荷电效果相对较差。以冲击式摩擦荷电器为基础,并采用平行板电极作为分选装置、螺旋给料器作为给料装置选择、布袋除尘器作为产品收集装置,开发出了通过气流输送矿粒进行分选的新型冲击式摩擦电选机,针对云南滇池地区中低品位磷矿进行的摩擦电选试验结果表明:对含P2O5 22.16%、Si02 33.31%的原矿,加入1%的碳粉磨细至-200目约占85%,在110 ℃的条件下预热24 h,经一粗两精一扫摩擦电选,可获得含P2O5 29.24%、回收率为71.45%的磷精矿和含P2O5 22.03%、回收率为13.14%的中矿,总回收率达84.55%,取得了较好的指标。
[Abstract]:Friction electricity separation is a kind of dry mineral processing technology with high efficiency, less pollution and no water consumption. Under the situation of the scarcity of global water resources and the increasingly serious pollution, people pay more and more attention to it. Friction electric separator is the key to realize friction electrical separation. After many years' development, many kinds of friction electric separator have been developed at home and abroad, but there are still some problems such as low charge, insufficient charge, small handling ability, easy wear and tear or mineral particle adhesion and so on. Our country is a big country of phosphate rock resources, but most of them are low and medium grade phosphate ores. It is necessary to raise the grade or remove impurities in order to become a qualified concentrate. The flotation method, which is widely used at present, has the problems of high cost and high pollution, so it needs to be improved urgently. It is of great theoretical significance and practical value to develop a new type of triboelectric separator combined with the mineral processing demand of medium and low grade phosphate ore. On the basis of analyzing the mechanism of mineral friction electroseparation, a new type of friction electric separator is determined to transport ore particles by air flow. Friction load apparatus is the core part of friction electric separator. Firstly, three new types of air flow friction load apparatus, such as impact friction load, oblique plate friction load and sawtooth wave friction load, are developed. The friction charge test of apatite and quartz pure minerals is carried out. The results show that: in the three kinds of friction charging apparatus, apatite and quartz can charge, and apatite has positive charge, quartz has negative charge; In the same friction charge apparatus, the law of friction charge between apatite and quartz is the same, while in different friction charge apparatus, the variation law of apatite or quartz with drying temperature is similar. The charge effect of impact friction charger is better at high air velocity, the advantage of inclined plate friction charge is in the range of low flow velocity, while the sawtooth wave friction charge can achieve better charge effect at high air velocity. But still inferior to impact type and inclined plate type two kinds of friction charge appliance; The optimum ratio of charge to mass is the largest, but the ratio of charge to mass per unit volume is small, the utilization ratio of internal space needs to be improved, the ratio of charge to mass per unit volume is large, and the utilization ratio of internal space is high. The internal surface area and internal friction plate area of sawtooth wave friction charging apparatus are both larger, but the charge / mass ratio per unit volume is small, the feed rate is smaller, and the charge effect is relatively poor. Based on the impact friction load apparatus, the parallel plate electrode is used as the sorting device, the spiral feeder is selected as the feeding device, and the bag dust collector is used as the product collection device. A new type of impact friction electrosorter was developed for separating ore particles by airflow. The results of triboelectric separation test for medium and low grade phosphate ore in Dianchi Lake area of Yunnan Province showed that the raw ore containing P2O5 22.16% Si02 33.31% was obtained. Adding 1% carbon powder to -200 mesh accounts for about 85%, preheating at 110 鈩，

本文编号：2340699