Development of Dolomite Blocks: A Brief Survey

Kiran Gupta , Mr. Piyush Das , Mr. Akshit Lamba

Dolomite, PLC, Iron oxide, cobble, conctere.

In present scenario, dolomite brick/block is the most important stable refractory under the working conditions of Argon Oxygen De-carbonization (AOD). A positive permanent linear change (PLC) dolomite brick/block has higher life and most suitable for joints less refractory lining with no cobble stoning defects. So the development of dolomite bricks having positive permanent linear change during applications is a change for refractory manufacturing industrys. In the present investigation, dolomite refractory bricks were prepared by having different additive with an intention to get the positive permanent linear change of the brick. As we know, that Iron Oxide is a good additive for dolomite brick sintering. It has also been reported that monoclinic zirconia (m-ZrO2) additive improves the BD, CCS and PLC of dolomite brick. In this background, first trial composition was containing a fixed amount of 1% m-ZrO2 and different concentration and types of iron oxide. Mill scale containing Fe2O3 was added in two different concentrations 0.5%, 1% and in another trial 0.25% of nano Fe2O3 was added. Fe2O3 containing bricks showed a good improvement in BD and CCS due to the better sintering of dolomite grains in presence of liquid formation during sintering by the presence of Fe2O3.The CCS value was in the range 750-800 kg/cm2. However, the PLC value was negative in the range of -0.2 to -0.35%. Depending on this result, new additive, Chrome Green oxide was used. It has been found that the permanent linear change (PLC) tends to be positive with increase in Cr2O3content.

Volume 4 Issue 5, May-2019

Pages : 75 - 76