Three types of typical processes for powder surface modification

The surface modification process varies according to the surface modification method, equipment and powder preparation method

1.

This is the most widely used non-metallic mineral powder surface modification process coating online coatingol.

(1) Intermittent dry process

The characteristic is that the surface modification time (ie residence time) can be flexibly adjusted in a large range, but the particle surface modifier is difficult to coat uniformly, the unit product consumption is large, the production efficiency is low, and the labor intensity is high.

(2) Continuous modification process

It is characterized by better dispersion of powder and surface modifier, more uniform particle surface coating, less consumption of modifier per unit product, low labor intensity, and high production efficiency.

2.

Compared with the dry process, it has the characteristics of good dispersion of the surface modifier and uniform surface coating, but it requires subsequent dehydration (filtration and drying) operations

Inorganic precipitation coating modification is also a wet modification process

3.

(1) Mechanochemical/chemical coating compound modification process

The surface modifier is added during the process of mechanical force or fine grinding and ultra-fine grinding to chemically coat and modify the surface of the particles while reducing the particle size of the powder

The disadvantage is that the temperature is not easy to control; in addition, because the particles are constantly pulverized during the modification process, new surfaces are produced, and the particle coating is difficult to be uniform.

(2) Inorganic precipitation reaction/chemical coating compound modification process

The surface chemical coating modification is carried out after the precipitation reaction modification, which is essentially an inorganic/organic composite modification process
.
This composite modification process has been widely used for surface modification of composite titanium dioxide, that is, on the basis of precipitation coating SiO2 or Al2O3 film, titanate, silane and other organic surface modifiers are used to modify TiO2/SiO2 or Al2O3.
The surface of the composite particles is modified by organic coating
.

(3) Physical coating/chemical coating composite modification process

After the particles are physically coated, such as metal plating or coating, the surface organic chemical modification process is carried out
.