The rapid development of the steel industry has placed increasingly stringent demands on the quality and performance of refractory materials. Magnesium carbon bricks, renowned for their superior properties, have found extensive application in industrial production. Concurrently, electrofused magnesia has experienced rapid advancement alongside the evolution of magnesium carbon brick production technology. Electro-fused magnesia exhibits larger grain size, higher purity, and greater density, thereby meeting the requirements for manufacturing high-quality magnesium carbon bricks. Electrofused magnesia boasts advantages such as high purity, large crystalline grains, dense structure, strong slag resistance, and excellent thermal shock stability. Its primary crystalline phase is periclase, characterized by coarse grains in direct contact. It is extensively used in the preparation of high-grade magnesia bricks, magnesia-carbon bricks, and various unshaped refractory materials. It can also serve as a high-temperature electrical insulating material in electrical components.
Production Process of Electro-Fused Magnesia
In specific industrial production, the raw materials for different grades of fused magnesia also vary. Ordinary fused magnesia typically uses magnesite as its direct raw material, while large-crystal fused magnesia employs light-burned magnesia. The equipment utilizes buried arc furnaces, often employing three regenerative or non-regenerative graphite electrodes. The specific process involves: charging → ignition and raising the electrodes → gradual charging → smelting (magnesite sintered and melted by heat generated from high current) → natural cooling → crushing, grading, and sorting → storage. The electric melting temperature for fused magnesia exceeds 2750°C. Current Status of Fused Magnesia Production:
Electrofused magnesia production consumes substantial electrical energy, with comprehensive energy consumption per unit product being approximately 5-10 times that of sintered magnesia. Under China’s energy policies, it is classified as a restricted development industry. Currently, China’s overall electrofused magnesia smelting technology remains rudimentary, featuring basic equipment, predominantly manual operation, incomplete thermal engineering protocols, and inadequate operating procedures. This results in severe energy waste and environmental pollution, necessitating strategic upgrades. Therefore, analyzing the thermal processes and energy balance in electrofused magnesia production to identify effective energy-saving measures, enhance raw material utilization rates, and implement dust control solutions is imperative.
Key Technical Measures for Producing Fused Magnesia
(1) Research and Development of Comprehensive Energy-Saving Technologies: 1. Increase electric furnace power capacity, gradually phase out low-power furnaces, and adopt furnaces rated at 1600KVA or higher, even up to 3500KVA or 5000KVA; 2. Develop new energy-efficient electric furnaces equipped with intelligent functional controls to achieve energy-saving power supply; 3. Optimize and improve production processes and parameters.
(2) Dust control and waste heat recovery.
(3) Develop and produce new types of electrically fused synthetic sand.
