Iron powder particles

What are primary particles and secondary particles?

Reduced iron powder can be divided into compact body, powder body and colloid according to different dispersion degrees:

1) Those larger than 1mm are called compact bodies or solids,

2) Below 0.1mm is called colloid,

3) and between the medium and the powder body.

Powder body, referred to as powder, is composed of a large number of particles and the gap between the particles.

The smallest entity which can separate and exist independently is called single particle. Single particles, when aggregated in some form, form what are called secondary particles, in which the original particles are called primary particles.