Study On A New Technology And Its Mechanisms For Recovering Tungsten With A Flowsheet Of Iron Pre-release-predesliming-bulk Flotation Of Wolframite And Scheelite

Recently, the beneficiation indexes of tungsten flotation of yejiwei 500t/d dressing plant and 380 dressing plant in shizhuyuan nonferrous metals company in hunan province were poor. The causes were analyzed comprehensively. On the one hand, the existence of the primary slime existed in feeding ore,and the secondary slime produced by grinding prior to flotation could lead to the poor indexes.On the other hand, there were a considerable portion of magnetic minerals such as magnetite in the feeding ores.The low-intensity magnetic separation prior to tungten flotation was only one roughing, and the content of magnetic mineral in the flotation pulp was 2.0%～4.3%, with a WO3 grade of 0.14%～0.40%.If this part of magnetic iron mineral can't be pre-removed and entered the tungsten flotation operation,the grade of rough concentrate would be reduced greatly.This paperr proposed a new technology of low-intensity magnetic separation-flotation desliming-bulk flotation of wolframite and scheelite, the laboratory tests were completed, and the results being better than the same point in the spot processing were obtained.The low-intensity magnetic separation was strengthened by scavenging with a hand magnet(0.13T).Most of magnetite which can influence the grade and recovery of tungten rough concentrate was removed.The yield of ore slime in desliming operation was 3%～5%,the size distribution was about 10μm(0.010mm),which was very fine,and the grade of WO3 was flat or slightly higher than the run-of-mine, so it could be abandoned directly.Researches on the mechanism of low-intensity magnetic separation and flotation desliming:it can be seen from the particles size analysis of ore slime that the removed slimes were 2μm～30μm and the average size was about 10μm(0.010mm).The micro fine magnetite had"the high gradient effect",as the "steel wool" medium of the high gradient, which can reunite wolframite particles.From calculating the interaction potential with the extending DLVO theroy, it can be known that the EDLVO potential between scheelite and slime was always negative, expressing in the attraction between them. That the existence of slime and magnetite had severe influences on flotation, which was verified by theoretical calculation, accorded with the experiment.