Rice Husk Waste as an Exothermic Material for a Riser Sleeve for Steel Casting

This research examines the suitability of rice husk waste as an exothermic material for a riser sleeve for use in steel casting production. Exothermic sleeves are used in the steel casting process to compensate for shrinkage of the steel during solidification. Commonly, the exothermic sleeve consists of fuel materials, fillers, and binders. Rice husk waste has potential for use as a fuel material in the exothermic sleeve due to its high calorific value. For this study, rice husk waste was ground to gain a particle size of 60 mesh and then mixed with organic binders of 12wt%, 15wt%, and 18wt%. A H-sleeve was then formed by hand pressing, followed by drying. A series of quantitative tests were carried out to analyze the performance of the rice husk as an exothermic material. These include measurement of modulus extension factor (MEF) and the cooling rate of the steel casting within the liquidus-solidus temperature range. The test results show that the rice husk sleeve mixed with 12wt% of binder extended the solidification time from 273 seconds to up to 511 seconds within the desired temperature range. Furthermore, the best MEF of 1.69 was achieved using the rice husk riser sleeve. This meets the standard MEF value of an exothermic sleeve.