Magnesium oxide (MgO) is an important inorganic chemical raw material and is widely used in the paper industry. Here are some common applications:
1. Bleach
Magnesium oxide can be used as a pulp bleaching agent, replacing traditional sodium hydroxide (NaOH) or sodium sulfate (Na2SO4). It has the following advantages:
It can improve the brightness and whiteness of pulp.
Can reduce pollutant emissions in wastewater.
Can reduce production costs.
The mechanism of magnesium oxide bleaching pulp is:
Magnesium oxide reacts with hydrogen peroxide (H2O2) to form magnesium peroxide (MgO2), which has strong oxidizing properties and can decompose lignin and other impurities in the pulp into small molecular substances.
Magnesium oxide can also absorb heavy metal ions in the pulp, making the pulp cleaner.
2. Filling
Magnesium oxide can be used as a paper filler to improve the smoothness, whiteness and opacity of paper. It has the following advantages:
Low price.
Has good dispersion and filling properties.
It can improve the printability of paper.
The dosage of magnesium oxide filler is generally 5% to 15% of the paper mass.
3. Retention aids
Magnesium oxide can be used as a retention aid in papermaking to improve the retentivity of paper (the ability of paper to remain impermeable to ink or other liquids). It has the following advantages:
Can improve the strength and wet toughness of paper.
It can reduce paper fluffing and powder loss.
The dosage of magnesium oxide retention aid is generally 0.1% to 0.5% of the paper mass.
4. Other applications
Magnesium oxide can also be used in other aspects of papermaking, such as:
Pulping: Magnesium oxide can be used as a pulping additive to improve pulping efficiency.
Wastewater treatment: Magnesium oxide can be used as a wastewater treatment agent to neutralize acidic substances in wastewater and absorb heavy metal ions in wastewater.
Application prospects of magnesium oxide in papermaking
With the development of the papermaking industry, the requirements for environmental protection and energy saving are getting higher and higher, and the application of magnesium oxide in papermaking will become more and more extensive. Magnesium oxide is a green and environmentally friendly chemical raw material that can reduce environmental pollution from the papermaking industry. In addition, magnesium oxide is cheap and can reduce paper production costs. It is expected that magnesium oxide will play a more important role in the paper industry in the future.