![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
Abstract
Most of the naturally occurring iron, titanium and chromium bearing minerals which accompany industrial minerals, such as quartz, feldspar, nepheline syenite, spodumene, andalusite, vermiculite, etc., exhibit either ferromagnetic or paramagnetic properties and can therefore be removed by means of magnetic treatment.
Magnetic separators powered by either permanent magnets or electromagnetic coils, have been widely applied to removing iron titanium and chromium bearing impurities from industrial minerals. The removal of these impurities have significantly improved the quality of the industrial minerals processed.
The early magnetic separators used for mineral processing were exclusively resistive electromagnets using water cooled copper coils. About 9 years ago, superconducting magnets made their first entry into this application and since that time their number and popularity has steadily increase.
Equally importantly the development of superconducting magnets systems has brought about notable improvements with regards to process economics, ease of installation and separation flexibility which make it practical for a great number of kaolin producers to benefit from this technology.
Dissolved metals from industrial effluents are usually precipitated as hydroxides or sulfurs. The precipitate is then decanted and filtered with the final cake stored in basins or lagoons. Magnetic separation (or magnetic filtration) can be used to decrease the separation time between mud and liquid. The conventional method consists of doping the mud with magnetic seeds (fine magnetite or hematite) which are incorporated in the preexisting flocculates.
A magnetic carrier can also be generated by coprecipitation of the element to be removed with ferric chloride, ferric nitrate or with a mixture of FeII /FeIII.
Magnetic filtration is also greatly improved by the use of a superconducting magnetic separator.
This article describes a superconducting filtration prototype and presents the main results of magnetic purification obtained in mineral processing and with synthetic solutions of cadmium, zinc, iron, ⃛ and industrial effluents.