STUDY OF THE CONCENTRATON OF "ULTRA-LOW-GRADE MAGNETITE

In this paper, the conecntration technology of "ultra-low-grade magnetite"and its economic bene-fit are discussed. A flowsheet of grinding and separating in stages is carried out for processing this kindof ore. In the process, the primary grinding is an "ultra-coarse grinding", so the bulk of the gangueof extremely coarse particle size is ejected in the rouphing stage. Thus the capacity of the primarygrinding can be increased more than twice. The operting cost per unit ore will be reduced by a greatextent. Higer economic benefit may be obtained to process the ore with grade 17% and concentrationratio 5.8.