Popular Science | The Use of Magnesium Oxide Powder in Electric Heating Tubes

Magnesium oxide (MgO), commonly known as magnesia, light-burned powder, or magnesium oxygen powder, is a pale yellow powder with a density of 2.94. It has a melting point of 2852°C and a boiling point of 3600°C. MgO is soluble in acids and ammonium salts but poorly soluble in water and ethanol. When calcined at 400°C, its specific surface area is 180 m²/g, but at 1300°C, it reduces to just 3 m²/g. MgO is hygroscopic in air and is classified as an air-hardening binding material. Magnesium oxide powder is categorized into various grades, including high-grade lubricant, food-grade, medical-grade, silicon steel-grade, high-grade electromagnetic, and high-purity magnesium oxide.

In the field of electric heating, heating tubes are composed of heating wires (heating elements), metal sheaths, and insulating magnesium oxide powder. Due to its excellent magnetic conductivity and superior insulation properties, magnesium oxide powder effectively transfers heat from the heating wire to the outer shell of the heating tube and secures the heating wire in place.

Depending on the operating temperature, magnesium oxide powder can be classified into low-temperature, medium-temperature, and high-temperature types. The choice of filling material significantly impacts the price and lifespan of the heating tube.

Important Notes

Since magnesium oxide is one of the most critical materials in heating tubes, it is essential to conduct relevant performance tests on the powder before use to prevent potential issues. Leakage current testing is particularly crucial. Additionally, magnesium oxide powder should be stored in a ventilated, dry environment, and protected from dust and other contaminants.

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The content in this article is compiled from various online sources, and the copyright belongs to the original authors.

World Electric Heating Industry Exhibition & Coference 2025

Since its inception in 2005, the Guangzhou International Electric Heating Technology & Equipment Exhibition has been Asia's first professional exhibition focused on the electric heating industry. Over the past 16 years, it has successfully established itself as a global one-stop platform for brand promotion, channel expansion, technical exchange, trade deals, and networking. The exhibition has become a premier event for industry professionals to "trade nationally and connect globally."

- Exhibition Dates: August 8–10, 2025  

- Venue: Guangzhou-China Import and Export Fair Complex

- Scale: Expected to feature 300 exhibitors and attract 20,000 domestic and international visitors.  

- Exhibits: Electric heating appliances, heating equipment, raw materials and components for heating tubes, manufacturing equipment for heating tubes, etc.  

- Concurrent Exhibitions: The event will be held alongside exhibitions on solar photovoltaics, heating and HVAC, energy storage batteries, air-source heat pumps, air conditioning and cold chain, power supplies, and other clean energy and energy storage topics. Over 15 exhibition halls are expected to be open simultaneously.  

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