Industrial Calcium Byproduct Waste: Sustainable Construction Materials for Building Applications

A sustainable and novel approach has been explored for utilizing calcium-rich byproduct waste as a pragmatic solution to address solid industrial waste generation. This initiative advances new construction technologies by developing cement-free wall putty. Industrial activities generate calcium-rich byproduct waste on million-ton scale, which is often disposed of in the open environment, leading to its accumulation in landfills. Production of a large volume of industrial calcium byproduct waste creates serious environmental challenges and several negative consequences like depletion of soil fertility, impact on biodegradation processes, etc. Although utilization of industrial byproduct waste in solid waste management has been extensively documented in scientific literature, to the best of our knowledge, research on the utilization of calcium byproduct waste for the development of cement-free wall putty remains unexplored so far. However, commercially available wall putty is composed of dolomite, white cement, and cellulose polymer additives. The outlined scheme utilizes calcium byproduct waste of the acetylene gas industry and pulp industry as calcium hydroxide and calcium carbonate, respectively. Despite the modification in raw materials, the resulting wall putty exhibits properties and performance almost similar to those of commercially available wall putty with the added advantage of being safe and free from heavy metal ion contaminants. The unique selling proposition of this putty powder lies in its low carbon footprint as a construction material, free from white cement. Additionally, it offers superior performance by resisting cracking and flaking of paints, ensuring long-lasting and durable wall finishes. The X-ray diffraction profile of the putty powder reveals the crystalline structure of the calcite and portlandite phases. SEM studies show an agglomerated structure due to attractive van der Waals interactions of the putty paste containing hydroxyl functionalities with the polymer matrix. Scalable strategies outlined in this article not only align with domestic technological development but also promote the waste-to-wealth approach, contributing to recycling and reuse of byproduct waste. The presented initiative supports several United Nations Sustainable Development Goals which emphasize the importance of sustainability in industrial practices, environmental concerns, and restoration materials for conservation of cultural heritage structures.