DEVELOPMENT OF AN ELECTRIC FURNACE USING BENTONITE AND KAOLIN SODIUM SILICATE AS REFRACTORY MATERIAL

Abstract

The search for improved refractory materials to enhance the performance of the furnace is still a basic factor in the heart of researchers. Production of high temperature furnace with good performance for pilot scale has been limited due to the grade of refractory available to the manufacturers. The research is aimed at developing an electric furnace using bentonite and kaolin with sodium silicate as refractory material. The developed furnace was designed using solid works software. The materials used in the fabrication of the designed furnace were mild steel of 2 mm thickness, angle bar of 6 mm thick, hinges, bolts and nuts, fibre glass and composite material (Bentonite, Sodium silicate and Kaolin). The materials considered for electrical unit were heating element, control switch, temperature controller and thermocouple capable of measuring to maximum temperature of 1300℃. The furnace was fabricated with inner and outer dimensions of 276 × 276 × 276 mm and 346 × 346 × 346 mm, respectively. The ratio of the composite material of Bentonite, Sodium silicate and Kaolin used was calculated using thermal conductivity analysis. The performance of the developed furnace was evaluated using 5 kg of brass and five samples of aluminium of 1, 2, 3, 4, and 5 kg to determine the throughput and its efficiency. The throughput of the developed furnace gave 21.02𝑚3 with Bentonite, Sodium silicate and Kaolin ratio of 1:1:40. The efficiency of the developed furnace in terms of maximum temperature and heating rate are 96.2% and 73.1% respectively. The developed furnace is therefore suitable for use at higher temperatures than the existing furnace which is suitable for graphitization of carbonaceous materials. Hence, this furnace is recommended for use in research laboratories and small-scale foundry industries where the heat needed is within the attained temperature.