Further attachement of water follows in the fluid state thus enabling the lamellar particles to slide along their surfaces. The liquid H2O molecules appear to be attached to OH ions. Polar liquids form thicker salvation layers than non polar. Only the former are capable of rendering clays plastic. Talc which has the same lattice form […]
The upper surface of the lattice consists of OH groups which form equilateral triangles. The other face is formed by O atoms in hexagonal arrangement. The spatial arrangement of the H2O molecules in ice and water results in the atomic distances between the oxygen atoms. Being approximately the same as those in the O and […]
The complicated relationships between clay and water can be explained by the intercation of 4 factors;
1. The negative charges on the clay particles.
2. Their lamellar form.
3. The adsorption of water on the particles.
4. The high surface tension of water.
The kaolinate lattice is electrically neutral. It becomes negatively charged only on adsorption of OH ions from […]
Charges of the same sign and liquid envelops surrounding the particles prevent their colloiding. Molecules of the liquid in the envelops are bound to particular atomic routes in the surface of the solid particles by chemical bonds. In the case of clay both cations and anions can be adsorbed which proves presence of positive and […]
Colloids may be solvated (lyophilic) or non solvated (lyophobic). Clays belongs to lyophilic group. Electric charge on clay particles is one of the causes of the stability of suspensions, solvation is another. Because of the heterogeneous nature of salt substances with high di-electric constants must be charged positively in relation to those with lower di-electric […]
14. Test for flow behaviour
Prepare samples of different clays to be tested as follows:
The clay to be tested has to be taken out from the bulk supply by ‘Cone and Quarter’ method - the sample to be prepared is around 1 kg. From this master sample take out about 500 gms and soak it in […]
13. Test for chemical composition
The chemical composition of clay is very important to find out its suitability for various applications. The following elements have to be determined:
SiO2
Al2O3
CaO
MgO
TiO2
Fe2O3
Nowadays very recent advanced equipments are available like Atomic Absorption SpectroPhotometer, which gives within few seconds, the chemical composition of the clay to be tested. By using such equipments […]
12. Test for fired strength
The clay to be tested has to be taken out from the bulk supply by ‘Cone and Quarter’ method - the sample to be prepared is around 2 kg. From this master sample take out about 1 kg and soak it in distilled water about 400 ml. After soaking, stir it […]
11. Test for green strength
The clay to be tested has to be taken out from the bulk supply by ‘Cone and Quarter’ method - the sample to be prepared is around 2 kg. From this master sample take out about 1 kg and soak it in distilled water about 400 ml. After soaking, stir it […]
10. Test for permeability
The clay to be tested has to be taken out from the bulk supply by ‘Cone and Quarter’ method - the sample to be prepared is around 1 kg. From this master sample take out about 500 gms and soak it in distilled water about 250 ml. After soaking, stir it for […]
