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The iron ore produced in Hunan, China, is characterised by the presence of micro-fine haematite with a particle size of 1-3 micrometres. Effective beneficiation using conventional processes cannot be achieved due to the complex dissemination of haematite in gangue material. Direct reduction tests were carried out using an ore containing 40.07% total Fe, 1.65% FeO, 55.41% Fe2O3, 34.93% SiO2, 3.93% Al2O3, 0.69% CaO and 0.66% MgO. Direct reduction using coal at 1 200 degrees C for 90 minutes with a C:O ratio of 2 yielded a product with a degree of metallisation of 93.24% and a reduction rate of 95.49%., The iron ore produced in Hunan, China, is characterised by the presence of micro-fine haematite with a particle size of 1-3 micrometres. Effective beneficiation using conventional processes cannot be achieved due to the complex dissemination of haematite in gangue material. Direct reduction tests were carried out using an ore containing 40.07% total Fe, 1.65% FeO, 55.41% Fe2O3, 34.93% SiO2, 3.93% Al2O3, 0.69% CaO and 0.66% MgO. Direct reduction using coal at 1 200 degrees C for 90 minutes with a C:O ratio of 2 yielded a product with a degree of metallisation of 93.24% and a reduction rate of 95.49%.

The reduction of 1-3 mm particle size Australian haematite of bulk density of 2 020 kg/m3 by 50% CO-50% N2 was studied using a laboratory-fabricated, kg-scale, high-temperature fluidised bed. The degree of reduction of the sample was found to increase and the utilisation ratio of gas to decrease for longer reaction times. The utilisation ratio of gas reached about 8% and the degree of reduction was 80% for a 20-min reduction at 850 degrees C, indicating that at high temperature the reduction reaction by CO was very fast. The higher the reaction temperature, the higher was the apparent rate constant. The apparent activation energy was about 59.11 kJ/mol in the fluidised-bed experiment. The increase in the degree of reduction with gas velocity showed quite good linearity. With an increase in charge height, the metallisation ratio and the degree of reduction decreased but the utilisation ratio of gas increased., The reduction of 1-3 mm particle size Australian haematite of bulk density of 2 020 kg/m3 by 50% CO-50% N2 was studied using a laboratory-fabricated, kg-scale, high-temperature fluidised bed. The degree of reduction of the sample was found to increase and the utilisation ratio of gas to decrease for longer reaction times. The utilisation ratio of gas reached about 8% and the degree of reduction was 80% for a 20-min reduction at 850 degrees C, indicating that at high temperature the reduction reaction by CO was very fast. The higher the reaction temperature, the higher was the apparent rate constant. The apparent activation energy was about 59.11 kJ/mol in the fluidised-bed experiment. The increase in the degree of reduction with gas velocity showed quite good linearity. With an increase in charge height, the metallisation ratio and the degree of reduction decreased but the utilisation ratio of gas increased.