Low-Temperature Carbothermic Reduction of Indonesia Nickel Lateritic Ore with Sub-Bituminous Coal
In this work, the experiment was conducted to investigate the effect of temperature and sub-bituminous coal on upgrading nickel laterites ores by carbothermic reduction. The reduction was carried out in the muffle furnace at a temperature ranging of 800-1100 °C. The produced calcine from reduction step was grounded in vibrating mill, mixed with water and passed on a magnetic separator to separate nickel concentrates from the tailing. The experimental results showed that the concentrate with highest nickel grade was produced at temperature 1000 °C. The nickel grade on concentrate was 5.0 %, with the recovery of nickel was 80.6 %.
Open Access proceedings Journal of Physics: Conference series
The use of biomass carbon as a reducing agent in lateritic nickel ore reduction is one alternative to substitute dependence on conventional reducing agents such as coal and cokes. The difference in particle size distribution from reduced ore shows differences in characteristics that can be used as a reference in the next step extraction process of lateritic nickel ore. In this study, characterization of lateritic nickel ore reduction at high temperatures using coconut shell charcoal as a biomass carbon reducing agent. Reduction process was carried out at 1200 O C and holding for 90 minutes, heating continued until 1500 O C and held for 15 minutes. Effect of particle size distribution from lateritic ores reduction was investigated by chemical composition, especially changes in the composition of iron and nickel. Also, mineralogy analysis and microstructure characterization were performed to analyze compounds, morphology and elemental mapping analysis after reduction in each particle size distribution.
Numerical and experimental investigation on air distributor design of fluidized bed reactor of sawdust pyrolysis
Abstract An improved biomass conversion in a lab-scale fluidized bed reactor (FBR) is achieved by optimizing the air distributor orifice size and number. Two approaches for introducing air were numerically and experimentally examined. These included perforated plate and downward orifice sparger. 3 mm and 5 mm orifice diameters, and 7, 9 and 13 holes were simulated at flow velocities of 2, 4, 6, and 8 times the minimum fluidization velocity, Umf. The simulation results revealed that increasing the orifice number has a positive effect on gas holdup, particularly for the perforated plate, which showed a uniform distribution of bubbles. The sparger configuration produced larger bubbles sizes, which could lead to better recirculation of solid flux, while stagnant particle zones were observed at the lower section of both distributors. A pyrolysis unit is also inserted at the top of freeboard of the FBR. For perforated plate with 6Umf, the pyrolysis process achieved thermal and cold gas efficiencies of 82.91% and 52.03%, respectively, while combustible gases with 41.6%mol CO, 8.7%mol CH 4 and 2.17%mol HC, were obtained. For sparger pipe and 6U mf _sp, 35.33 ppm NOx and 111 ppm SO 2 were measured in flue gas from combustion process at bed region.