Development of Red Mud Based Composite Material to Enhance the Strength

Abstract

Red clay is a solid waste product of the Bayer process, which extracts alumina from bauxite. Red mud, as it is known by name, is brick red in colours and diluted with an average particle size of <10 µm. The red colour is caused by oxidized iron being present. India is one of the leading producers of alumina in the world. Red mud cannot be easily handled in most countries where red sludge is produced, it is kept in ponds. Red mud is alkaline in nature; hence it is dangerous for the environment. Its disposal is a worldwide problem in terms of environmental concerns. During the last decades, extensive work has been done to create various economic methods for the use of red slime by many global researchers. Some researchers tried to develop fly ash composites used to support underground roof. In order to utilize the red mud to a certain extent, the red mud-based composite material has been developed to enhance the strength and can be used in the underground mines to support the roof as the replacement of wooden props. In this dissertation, many aspects of the production and characterization of red mud in the world and Indian context have been discussed and properties are measured through XRD, SEM analysis and pH determination.
Red mud has rich in iron content especially BALCO plant, Korba as compared to other aluminium plant in India and found that it can be used as a composite material because of its higher strength as a supporting purpose in mining. For further enhancement of the strength of red mud, lime and black stone are used as a binding agent in proportion with red mud. Unconfined compressive strength and Brazilian tensile strength are carried out for different composition of red mud and lime for different curing period. It is also economical and easier to handle. In this study, we obtained compressive strength 4.7272 kg/cm2 when a load of 1.004 tonnes was applied in 28 days curing period and tensile strength 21.176 kg/cm2 was found by using composite sample (consisting of 82% red mud+10% lime+8% b.stone).