Electrical grade magnesium oxide powder is an insulating and thermally conductive powder filled between the heating wire and the metal outer tube. It is made of electrofused crystalline MgO block by crushing and combining in specific proportions of different particle sizes (mesh) either directly or after modification. It is used in electric heating tube components as an insulation medium for heat conduction at high temperatures, referred to as magnesium oxide.
Uses of Magnesium Oxide Powder
- Secures the center of the resistance wire.
- Ensures that a metal shealth is not electrified (insulated).
- Conducts heat emitted by the resistance wire.
How To Choose Magnesium Oxide Powder?
The insulation filling material should be selected according to the component’s operating temperature.
Working temperature T ≤ 400 C, filled with low-temperature MgO powder. The silicone oil treated low-temperature MgO powder is mainly used for making low-load electric heating elements and liquid electric heating elements with low requirements. Electric heating elements made with this type of powder do not need to drain moisture and seal because they have excellent moisture-proof performance.
- Working temperature 400℃ <T ≤ 600℃, filled with medium-temperature MgO powder. The silicone oil treated medium and low-temperature powder is mainly used to make high requirements of low load electric heating elements and liquid electric heating elements. Electric heating elements made with this ype of powder do not need to drain moisture and seal because they have excellent moisture-proof performance.
Working temperature 600℃ <T ≤ 850℃, filled with high-temperature MgO powder, high-temperature MgO is mainly used to make medium load and high load of air-fired electric heating element and can withstand the heat treatment of 1050℃. Moisture needs to be drained and sealing treated promptly.
How To Preserve High Purity Magnesium Oxide Products?
MgO is best stored at room temperature with humidity at less than 60%, as MgO deteriorates with moisture and water. If stored improperly, its active content will be reduced, thus affecting production. When buying high-price and high-quality MgO, effective technical storage must be adopted:
If unwilling to pour out and change packaging bags, cover the original packaging with a plastic film and lay the plastic film on the ground. This method can be used to prevent moisture.
The packaging should be well sealed. If opened, the packaging bag must be sealed promptly.
Place lime blocks around the bags of MgO after palletizing to prevent moisture. This is another way to avoid MgO absorbing moisture and reducing active content.
Since calcium oxide has stronger moisture absorption properties, placing calcium oxide in the warehouse is highly effective as a moisture-reducing agent to lower the humidity in the warehouse.
The longer the MgO is stored, the greater the conversion amount into Mg(OH)2, and the lower the active content. So, MgO cannot be kept for too long a period. Therefore, avoid purchasing a large quantity of MgO at one time. Use it up within a month as the benchmark; the most desirable is to use it up in half a month.
Moisture Absorption of Magnesium Oxide Powder
MgO will chemically absorb moisture if stored for more than one year without use, so it should be dried at 500℃ for 4 hours before use.