Utilisation of Pond Ash in Brick Making
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Pond ash is a byproduct of coal-fired thermal power plants, and it has immense potential for making fly ash brickmaking, which contributes significantly to both sustainability and waste management. It contains a notable amount of fly ash, and when combined with sand, stone dust, and cement, it serves as a sustainable alternative to red clay bricks. This helps to mitigate coal combustion and soil degradation occurring at a faster rate owing to rapid urbanisation and uptake in the demand for real estate. The utilisation of pond ash addresses a circular economy, where industrial waste is transformed into productive and valuable construction materials.???
Our Work
A survey conducted by the Development Alternatives team in the Muzaffarpur district of Bihar aimed to understand the impact and potential of utilising ponded ash. The district is strategically located in the northern part of Bihar, near neighbouring countries like Nepal and Bhutan. This facilitates the expansion of its market reach for building materials, as well as accessibility of roads and railways. Availability of pond ash from NTPC Kanti and the state government’s emphasis on infrastructure development and economic growth enables the setting of ponded ash enterprises in the district. A quality audit was conducted on the fly ash bricks of several companies, following the guidelines of the Bureau of Indian Standards (BIS) and the Fly Ash Bricks Quality Rating System (FABQRS). The quality assessment revealed distinctive properties in terms of metallic sound, showcasing structural integrity and uniformity in composition, smooth and even surface, with well-defined corners, demonstrating production accuracy. The curing process was very effective, taking only about a week to reach the optimal levels of strength and durability. The expedited curing time improves production efficiency and availability of bricks for construction. The raw materials used in the production process near Muzaffarpur are pond ash, cement, stone dust, and water. Due to the unavailability of lime, cement is primarily used as the binder for brickmaking.
Impact of Pond Ash Brick Making
The utilisation of pond ash in brickmaking offers many benefits in terms of environmental, economic and structural aspects. From an environmental perspective, pond ash reduces carbon emissions by decreasing clay bricks, cement, and coal combustion, all of which are associated with significant greenhouse gas emissions. It also helps in reducing soil degradation by conserving topsoil. Pond ash bricks offer structural advantages such as superior quality compared to conventional clay bricks, dimensional accuracy, and uniformity in size, which enhances construction quality. These bricks are fire resistant and lighter in weight, reducing the overall load on structures. Additionally, the brick-making process harbours year-round employment opportunities, countering seasonal employment, and helps transition labourers from labour intensive to mechanised processes, improving their working conditions and offering higher remuneration while diminishing their exposure to harmful suspended particles and gases experienced in clay brick kilns.
The ponded ash industry in Muzaffarpur, Bihar, faces several challenges. These challenges can be addressed by streamlining procurement processes, addressing the pricing disparities faced by the entrepreneurs, and ensuring fair allocation of fly ash by the thermal power plants. Additionally, fostering demand, improving quality assurance, offering benefits, and advancing efficient government support will be crucial. Implementing training, certification, and mandating usage near NTPC plants will promote sustainable practices. The utilisation of pond ash in brick making, particularly in regions like Muzaffarpur, showcases ample opportunities for entrepreneurs and favourable outcomes spanning environmental, structural, and economic considerations, thus significantly fostering sustainable development.