Study, Design and Development of an Electric Crucible Furnace for Laboratory Use from Local Malagasy Raw Materials

Abstract

This study addresses the critical challenge of high-temperature laboratory equipment acquisition in developing regions by validating the technical and economic feasibility of fabricating an electric crucible furnace utilizing regional Malagasy resources. The physicochemical and mineralogical traits of four local raw materials—refractory clay, Vontovorona kaolin, Mahela graphite, and rice husk ash—were systematically characterized to establish an unprecedented regional materials database. Six distinct ternary composite formulations were developed and fired under localized protocols to produce high-temperature insulating bricks. Microstructural testing revealed that all configurations achieved excellent thermal stability, marked by residual mineral ash yields exceeding 95.00% and an optimized open porosity framework spanning 38.13% to 45.50%. Formulation E6, composed of an equimass clay-to-kaolin ratio, demonstrated the highest structural consolidation, exhibiting relative increases of 72.6% in splitting tensile strength and 90.8% in uniaxial compressive strength (reaching 1.845 MPa) compared to the baseline mixture. Practical operational validation was successfully achieved through aluminum scrap recycling trials, during which the integrated Proportional-Integral-Derivative (PID) control loop, solid-state relays, and Type-S thermocouple maintained a stable process temperature of 800°C. Economically, the total production cost of 653,410 MGA represents a tenfold reduction compared to imported commercial counterparts. By bridging traditional low-cost artisanal fabrication methods with high-precision electronic thermal regulation, this research introduces a highly transferable intermediate technology model. This prototype successfully fosters circular economy pathways via localized non-ferrous metallurgy while providing a reproducible framework for equipping academic and research laboratories across the sub-region at minimal cost.