ON OXIDATION DEGREE, REDUCTION DEGREE AND REDUCIBILITY OF IRON ORE

Abstract

TThe correlation among several methods of indicating oxidation and reduction degree of iron ore and their difference were explained and the most reasonable lnethod by which indicatioll of net reduction degree was possible was established. Several tests were conducted on the size and porosity of ore, flow quantity of CO gas per unit time, rate of mixing coke, reduction temperature and reduction time which were regarded as the factors having an influence upon the reducibility of iron ore.
In reduction tests with CO gas and coke, better reducibility was obtained with finer ore. Within this test conditions, this trend was observed in the case of the ore especially under about 1.0 mm in diameter, while it was not so remarkable in the larger size ore. In the case of reduction with coke the highest reduction-degree was obtained with a mixing of 30% coke. Reducibility with CO gas showed a gradual increase with an increase of flow quantity of CO(cc/min.) As an influence of porosity on reducibility, increase of 10%in porosity brought about an increase of about 10-13% in the reduction-degree. As to hematite, based chiefly on the result of reduction test, the relative correlation amollg flow quantity of CO gas, ore diameter and reducibility CO gas was considered. And it was presumed that flow quantity of CO gas had more influence on reducibility with CO than the ore diameter in case of large size, and that the effect as the product of a mass of flow quantity of CO per unit time and reduction time was observed.