The effect of organic substances present in clays on origination of the blackheart in ceramics

When clayey rocks are heated, the decomposition of organic matter is accompanied by the release of Н ₂ , СО and СО ₂ , which create a reducing nature of the gaseous environment. Burnout of residual carbon occurs in the temperature range 250 - 500 ° C and is extreme due to oxygen diffusion into the inner layers of the heat-treated material. To exclude the black core, it is recommended to provide exposure in the temperature range of 700 - 800 ° C to complete the oxygen burnout process, as well as to mold hollow products with the minimum permissible thickness of the outer and inner walls. Tab. 2, ill. 2, bibliography: 6 titles.