Abstract
Regarding the reduction under load test for measuring high temperature properties of blast furnace burdens, the test conditions, i.e. the load, gas flow rate, particle size and bed height were examined through tests and calculations based on a reduction model for fixed bed. Examinations covered also evaluation criteria of test results for high temperature properties.
The results obtained are summarized as follows :
(1) Test results are influenced by each of the load, gas flow rate, particle size and bed height conditions.
(2) It is desirable to minimize the longitudinal difference of degree of reduction and the dependence on load of test results. The optimal test conditions (Fig. 2) were decided from such a point of view.
(3) The following evaluation criteria of test results for high temperature properties were proposed : i) the temperatures at the beginning of softening and melt-down are high, with a small temperature difference; ii) the integral and average values of index of permeability resistance between softening and melt-down are small; and iii) the degree of reduction achieved at 1 000 to 1 200°C is high.
