A Hydrometallurgical for the Extraction Process of Iron from Low Grade Orest
C. P. Gravenor, G. J. Govett and T. Rigg Research Council of Alberta, Edmonton, Alta
. In 1953, a deposit of sedimentary oolitic iron ore was discovered in the Clear Hills area of northwestern Alberta. Since that time, detailed drilling has outlined reserves in excess of 200 million tons of ore grading 30 to 35 per cent iron. Attempts to physically beneficiate the ore to meet blast furnace or direct reduction feed specifications have been, in general, unsuccessful. In 1960, Premier Steel Mills Limited and the Research Council of Alberta jointly sponsored a pilot-plant test at the R-N Corporation at Birmingham, Alabama. About 5,000 tons of ore were treated, and briquettes containing 90 per cent Fe were produced, with 83 per cent recovery. At the same time that the R-N tests were being made, the Research Council initiated a program to produce high-purity powders by chemical methods. Several purification techniques were investigated; hydrochloric acid dissolution of reduced ore was finally adopted. Briefly, the steps involved in this acid process are as follows:- (1) roast the ore with coal in a reducing environment to convert the ferric oxide and other iron-bearing materials to metal and ferrous oxide, (2) dissolve the roasted material in hydrochloric acid, (3) filter to remove the insoluble impurities, (4) crystallize and separate the hydrated ferrous chloride crystals, and (5) dry the ferrous chloride crystals and reduce in a hyrogen atmosphere at elevated temperature to produce iron powder and hydrogen chloride. Hydrochloric acid is recovered and recycled in the system. The iron powders so produced are of high purity - 99 per cent Fe - and non-pyrophoric, and preliminary tests indicate their suitability for powder metallurgy. It is believed that with the low-cost ore, and with low-cost fuel available in Alberta, iron powders can be produced at costs comparable to those of conventional iron-making processes.
Alberta, Chloride, Chlorides, ferric chloride, hydrochloric, iron chloride, Northern Alberta, Table V-Composition of Iron Powder, Iron, Materials, Ore, Ores, Process, Processes