Calcium carbide residue - a key inorganic component of the sustainable carbon cycle

The transfer of waste materials from the chemical industry to the building sector is an emerging area of sustainable development. Leftovers, by-products, tails and sludge from chemical processes may be valuable components of building mixtures. Feeding the construction industry by chemical wastes is a profitable chain for both sectors. In fact, calcium carbide residue (CCR) can be considered a link between the chemical industry and construction materials. Carbide sludge is the main waste product of acetylene gas production from calcium carbide. The released acetylene is actively used in the modern chemical industry. An alternative method of acetylene production — the cracking of oil and gas — is beyond sustainability; thus, the carbide route is more promising in the hydrocarbon-free future. However, the carbide route is accompanied by a significant amount of the side-product carbide sludge, which is currently used as a CO₂ capture agent, binder, building material, in inorganic synthesis, etc. In this review, the potential of carbide sludge in the construction industry and other areas is highlighted.The bibliography includes 310 references.