Engineering development of high gradient magnetic separators

The commercial development of high gradient magnetic separation began in 1969 when the first industrial, cyclic high gradient magnetic separators were sold to the J.M. Huber Corporation by Magnetic Engineering Associates, Sala´s predecessor, for processing high grade paper coating clays. Since that time, high gradient magnetic separation for the processing of high quality clays has come to be fully accepted in the United States kaolin industry. A number of large cyclic separators of the Sala design, with capacity ratings above 60 tph have been constructed under license from Sala and installed in major U.S. clay producers´ facilities. Applications of high gradient magnetic separation technology to mineral processing and water treatment have been explored(1,2,3,4). The cyclic high gradient magnetic separators utilized in the clay industry may be employed for most water treatment applications since the volume of magnetic material to be removed is a relatively small percentage of the total flow volume through the machine. In the majority of mineral separation and beneficiation problems, the feed percentage of magnetics is more than 1 to 2 percent and to solve this problem efficiently a continuous high gradient magnetic separator has been developed by us. A 15 tph continuous pilot separator is now operating in our Cambridge pilot plant and is able to process ores with the effectiveness of the cyclic high gradient magnetic separators.