The magnetic substances in magnesium oxide mainly come from minerals such as magnetite and hematite in the raw materials. The following methods can be used to remove magnetic substances from magnesium oxide:
1. Magnetic separation
Magnetic separation is the most commonly used method to remove magnetic substances from magnesium oxide. It is simple to operate and highly efficient. The principle is to use the adsorption of magnetic substances in the magnetic field to separate them from magnesium oxide.
The specific steps for removing magnetic substances from magnesium oxide by magnetic separation are as follows:
① Crush the magnesium oxide raw material to a certain particle size, usually -2mm.
② Grinding to -0.074mm accounts for more than 80%.
③ Add water to form a suspension.
④ Strong magnetic separation is carried out under the condition that the field strength is greater than 15000Gs.
⑤ Separate the magnetic material from the magnesium oxide.
2. Chemical precipitation method
The chemical precipitation method is a method that uses chemical reagents to precipitate magnetic substances and then separates the precipitate from magnesium oxide.
The specific steps for removing magnetic substances from magnesium oxide by chemical precipitation are as follows:
① Grind the magnesium oxide raw material to a certain particle size, usually -2mm.
② Grinding to -0.074mm accounts for more than 80%.
③ Certain chemical reagents are added to the magnesium oxide raw material to precipitate the magnetic material.
④ Separate the precipitate from the magnesium oxide.
Commonly used chemical precipitation reagents include sulfuric acid, sodium hydroxide, calcium hydroxide, etc.
3. electrochemical precipitation method
The electrochemical precipitation method uses electrolysis to precipitate magnetic substances and then separates the precipitate from magnesium oxide.
The specific steps for removing magnetic substances from magnesium oxide by electrochemical precipitation are as follows:
① Grind the magnesium oxide raw material to a certain particle size, usually -2mm.
② Grinding to -0.074mm accounts for more than 80%.
③ Some electrolyte is added to the magnesium oxide raw material, and the magnetic material is precipitated under the action of an external electric field.
④ Separate the precipitate from the magnesium oxide.
Commonly used electrolytes include sulfuric acid, hydrochloric acid, sodium hydroxide, calcium hydroxide, etc.
The specific method to choose needs to be determined based on factors such as the content and properties of the magnetic substances in the magnesium oxide raw material, as well as the use of the magnesium oxide.
The following are the advantages and disadvantages of magnetic separation method for removing magnetic substances from magnesium oxide:
Advantage
Simple operation and high efficiency.
Suitable for different types of magnesium oxide raw materials.
Disadvantage
The particle size requirements for magnesium oxide raw materials are relatively high.
The requirements for the content of magnetic substances in magnesium oxide raw materials are relatively high.
If the content of magnetic substances in the magnesium oxide raw material is low, chemical precipitation or electrochemical precipitation can be used to remove it. Chemical precipitation and electrochemical precipitation have higher requirements on the purity of magnesium oxide.