Physical properties:

1. Color: white or near white, with the highest whiteness greater than 95%

2. Hardness: the hardness of soft kaolin is generally 1-2, and that of hard kaolin is sometimes 3-4

3. Plasticity: Plasticity refers to the performance that kaolin can be crushed, mixed with appropriate amount of water, and then kneaded into a mud ball. Under the action of external force, it can change its shape without cracks. When external force is applied, kaolin can still maintain its shape under stress. Kaolin has good molding, drying and sintering properties

4. Dispersibility: dispersibility refers to the nature of kaolin dispersed in water and in suspension, or called suspension and anti-flocculation. Kaolin is easily dispersed and suspended in water and can form stable and good suspension

5. Electrical insulation: kaolin has good electrical insulation performance, with resistivity greater than 1010 Ω cm at 200 ℃, and can be used as cable filler

Chemical properties:

1. Chemical stability, kaolin has good acid solubility

2. Cation exchange capacity. Cation exchange capacity of kaolin refers to the total amount of cations that can be exchanged by kaolin under the condition of PH value of 7, including exchangeable base and exchangeable hydrogen, with the unit of mmol/g, i.e. the cation exchange capacity that can be exchanged per 1g dry sample is generally 0.03-0.05mmol/g

3. Fire resistance. The chemical composition of kaolin is Al2O3 and SiO2, so it has excellent fire resistance. The fire resistance is 1770-1790 ℃