Oxidized taconite beneficiation by continuous high gradient magnetic separation

The continuous "Carousel" high gradient separator has been used in a pilot scale field test at the Hanna Research Laboratory in Nashwauk, Minnesota. Also, a new batch type magnetic separator acquired by Hanna was used to extend the range of some of the parameters affecting the separation of the oxidized taconite iron ores selected for this program. Three ore blends were used, one of which was similar to the sample on which tests were performed at MIT in a previous test program. The object of the field test was to produce a feed for the flotation pilot plant in which a successful flotation of a difficult-to-treat ore blend had been achieved. High iron recovery from the crude feed was sought as well as the rejection of a large part of the feed weight with a small iron content. Achievement of this goal would result in a considerable saving in reagent costs for the flotation process. The results of tests on the longer matrix used in the batch tests were very high recoveries. They were correlated closely with the results of continuous tests which were confined to short matrix lengths. A short discussion of flotation is included.