Disposal of slag of refined ferrochromium by obtaining a sintered and carbonized construction products

Abstract

The article investigates the material composition of refined ferrochromium slag. It has been confirmed that the main compound in the slag is dicalcium silicate. The disposal problem of self-disintegration slag in the current production of refined ferrochromium can be solved by controlling its basic capacity with obtaining stabilized lump slag that is not influenced to silicate decomposition. This became the basis to researches the production of non-disintegrating burnt construction products from slags using low-melting silica-containing additives that reduce the slag basicity. Briquettes roasting containing from 20 to 30% additives in the temperature range of 1200-1225 °C showed the possibility of obtaining ceramic construction products. Material analysis of the slag also showed that the slag components, such as calcium oxide and magnesium oxide, are compounds prone to the formation of carbonates, which leads to the setting between the slag particles. Which makes it possible to obtain construction products in the process of autoclaving processing of bricks from the slag in the carbon dioxide environment. The influence of fineness, slag moisture, and the dwell time of products in an autoclave in the carbon dioxide environment on the strength of the resulting pellets were evaluated in this paper. It was determined that moderate humidity, in addition to increasing ductility during pellet molding, also increases the strength of products after carbonization. Excessive grinding of slag negatively affected on the quality of the pellets. The increase in compression force during the pellets formation, on the contrary, increased the strength of the products. An increase in the duration of carbonization at constant pressure had a positive effect on the strength increase of pellets.