This will be used to manufacture low-carbon cement
Vedanta Aluminium Business has invited partnerships from cement producers for using its by-products for manufacturing low-carbon cement. The company expressed its interest for long-term collaboration with cement industry players on opportunities of using fly ash (a by-product in thermal power generation) and bauxite residue (a by-product of producing alumina from bauxite) in cement manufacturing, in a national workshop conducted with global industry experts.
The cement industry, which is exploring viable solutions to produce cement more sustainably, is the perfect circular economy partner for Vedanta Aluminium. Fly ash and bauxite residue, the two most voluminous by-products generated by the aluminium industry, can be used in cement and concrete manufacturing, providing cement manufacturers significant benefits in terms of quality output, cost and sustainability.
Fly ash can partially replace cement in concrete (or be used to produce blended cement), significantly improving durability and workability of cement. With a 30 – 33% blending ratio, fly ash can help save 270 kg of carbon emissions for every tonne of cement produced. Bauxite residue can be added to the raw mix in clinker manufacturing to replace virgin bauxite, improving its hydraulic properties and strength. Owing to high concentration of iron oxide and alumina, bauxite residue is a better substitute for laterite, used in clinker manufacturing.
Moreover, the residual caustic in bauxite residue helps in controlling the emission of sulphur when used directly, making it a better fit for the purpose. Both fly ash and bauxite residue being industrial wastes themselves, come with significant cost and energy advantages as well.
Vedanta Aluminium’s technical workshop was attended by over a hundred executives from the cement industry and featured globally renowned experts in this domain – Shreesh Khadilkar, ex-Director of Quality and Product Development at one of India’s leading cement producers, and Robin De Beer, a concrete technologist from South Africa with 40+ years of experience in gainful utilization of fly ash in concrete.
In line with its quest for fostering a circular economy, in FY21, Vedanta Aluminium supplied over 3 lakh metric tonnes of fly ash to various cement plants in India. Since Feb’21, the company has also supplied over 30,000 metric tonnes of bauxite residue to cement manufacturers. The Business is additionally supplying fly ash free of cost to hundreds of local brick making MSMEs in its catchment.
In FY21, Vedanta Aluminium supplied nearly 4 lakh metric tonnes of ash to brick manufacturers. Ash bricks are not only lighter and stronger than traditional clay bricks, but play a crucial role in preserving nutrient-rich topsoil from being used as the raw material. This amounts to estimated savings of 1.9 metric tonnes of topsoil for every tonne of ash brick manufactured. Besides, ash brick manufacturing is an eco-efficient process, contrary to the energy-intensive process of producing clay bricks in brick kilns that result in substantial greenhouse gas emissions. In fact, for every tonne of ash bricks manufactured, an estimated 5900 kg of carbon dioxide equivalent emissions is avoided.
