CYRIL DURRENBERGER wrote:
In some cases the mining companies would send the ore to a washing plant to remove sand and other impurities from the iron ore and in some cases it went to a sintering plant prior to being taken to the docks. But natural ore, as it was called, was not normally chemically treated prior to shipment from the docks. In the late 1960's the taconite process replaced the natural iron ore when the stocks of natural ore were exhausted (or in some cases in shaft mines it became to expensive to remove).Everything Cyril says is correct, but for those not already familiar with this topic, it should be emphasized that ALL iron ore is "natural," but as the grade (iron content) declined due to mining of the best stuff, it was no longer economical to ship it in its natural or as-mined state, and the taconite process was introduced, which beneficiates the ore (increases iron content).
Tony Thompson Editor, Signature Press, Berkeley, CA
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