磁性流体による比重選別 (第3報)

金属アルミニウムの他金属類からの分離

抄録

It has been considered desirable to develop effective techniques for utilizationof waste solids. The main waste solid is urban waste which includes garbage, paper, plastic, and others. Larger waste solids are scraps of home electric machineries, automobiles, etc. Except for iron, other metals are hardly recovered at this stage. Various researches continue in order to provide satisfactory systems for separation of different metals from each other. They are magnetic separation, sink-float separation using heavy dense medium suspension and sink-float separation using magnetic fluids. In particular, a sink-float separation using magneticfluids can be used to separate many kinds of nonmagnetic metals whose specific gravities are different. Electric magnets and kerosene based magnetic fluid were used at first with this system. However, the present composition of waste solids, it is inferior to the smelting method. Therefore, we used water based magneticfluid in view of its greater regenerative qualities. Also, we used ferrite permanent magnets with yoke because the cost price is lower.
This report concerns the separation of Al from mixture of Al and other, heavier nonmagnetic materials. Al-Zn, Al-Cu mixture (about 6 to 30mm), whose weight percent of Al is 50, havebeen separated almost perfectly within about 2 t/hr. It was found to be more difficult to separate a mixture that includes a greater amount of Al, however, nearperfect separation of Al-Zn mixture (about 6mm) whose weight percent of Al is 90has been obtained within about 1.2t/hr.