Physico-chemical characteristics of some common clays of Nizamabad were studied with the objective of determining their suitability in the manufacture of high strength black pottery. The study also revealed that the alternative raw material, namely, Nasirpur field clay could be used even up to 100% in complete replacement of the existing plastic clays like Dhuripur, Bhairopur and Nasirpur pond clays for the production of black pottery. The products developed also possessed the highest fired strength of about 400 kg.cm−2 at the firing temperature of about 850°C.

Psysico-chemical Characterization of Some Common Clsys of Nizamabad, UP and their Utilization in the Production of Black Pottery

Mineralogical compositions of five plastic fire clays, viz. Mohuamilan, Chittorpur, Barachatarma, Neyveli and Badampahar, have been determined by chemical analysis and X-ray diffraction studies on active clay components (< 1 μ e.s.d.). X-ray examination was done before and after heat-treatment of clays at 600° and 1025°C. The results indicated that the dominant mineral present in all the clays belonged to the Kandite group. Mohuamilan and Chittorpur clays were well crystallized kaolinite. Illite was found to be present in small amount in Neyveli and Badampahar clays. Non-clay minerals of varying nature in varying proportions were present in all the clays.

Mineralogical Analysis of Five Plastic Fire Clays: Chemical Analysis and X-ray Diffraction Studies

Experimental determination of elastic properties of the loose materials in the field of high pressures after heating

Three plastic fireclays, namely, Mohuamilan and Chittorpur from Bihar and Barachatarma from West Bengal have been taken to study their physico-chemical properties which include chemical analysis, plasticity, particle-size analysis, base exchange capacity, differential thermal analysis, X-ray diffraction, drying and firing characteristics etc. Results indicate that Barachatarma clay is better than the other two clays with respect to plastic property. Owing to the undesirable fired colour, none of the clays can be used where the colour of the product governs the quality of the same.

S. K. Guha

Papers

Physico-chemical Properties of some Plastic Fireclays