Design and use of a superconducting solenoid type magnetic separator in mineral processing

In mineral processing, the conventional magnetic separators are equiped with traditionnal magnetic circuits which develop a magnetic field of less than 2 T. The use of these circuits has nevertheless many disadvantages which are : magnetic saturation is easily reached, remanent field causes clogging, equipments are heavy, bulky and high energy consumption. Only a separator having a superconducting solenoid can contribute in solving most of the problems and produce high magnetic field (7 T). This paper presents and describes a magnetic separator with a superconducting solenoid with integrated closed circuit for helium liquefaction. The system generator and maintenance is simplified by extensive automation realized by a versatile programmable autocontrol unit. Comparative study : 1) Concentration of fine itabirite iron ore gives a concentrate of 68 % Fe and a recovery rate of > 98 % 2) Purification of raw materials such as glass sand and syenite nephelinie produces a purified concentrate with a lower content of paramagnetic minerals and reduces the operating costs (energy consumption).