Bulk analyzer for grade determination of iron ore fines by backscatter of cobalt-60 gamma radiation

An accuracy of +-0.7 percent Fe (95 percent confidence intervals) can be achieved for bulk samples of normal production ore dried to less than 1 percent free moisture. Apart from a preliminary crushing of lumpy ores to -6-mm particle size, no elaborate sample preparation is required. Analysis time is 10 to 20 min or less, depending on the size of the scintillation detector crystal used. Provided Fe ore grade is all that is sought, the technique is competitive with routine wet chemical analysis, which is subject to large sample preparation errors