|
Abstract To address the challenge of synergistically reducing carbon emissions in the cement industry through the large-scale utilization of calcium- containing industrial wastes, this study employed a self-developed mineralization device to directly mineralize phosphogypsum, flue-gas desulfurization (FGD) gypsum, and calcium carbide slag using kiln raw flue gas. The resulting mineralization products were comprehensively characterized and their applications were explored. The results demonstrated that the mineralization of phosphogypsum yielded calcium carbonate and ammonium sulfate— meeting the specifications for Type I fertilizer grade ammonium sulfate stipulate in the national standard GB/T 535–2020. In contrast, the ammonium sulfate derived from FGD gypsum mineralization contained halogen impurities, which formed colored complexes with iron ions. Consequently, after evaporation and crystallization, the resulting ammonium sulfate failed to satisfy the color, nitrogen, and sulfur requirements of GB/T 535–2020. Meanwhile, the calcium carbonate obtained from calcium carbide slag mineralization exhibited improved whiteness. Notably, calcium carbonate was the predominant solid product recovered from the mineralization of all three calcium-containing industrial wastes, and it is suitable for direct use as a raw material in cement production. This study systematically explores a technical pathway for coupling carbon emission reduction with the valorization of calcium-rich industrial wastes in the cement industry, offering valuable insights and practical reference for decarbonizing cement manufacturing
|
|
Published: 30 July 2026
|
|
|
|
2026, Vol. 0 
