Industrial by-product gypsum, also known as flue gas desulfurization gypsum, refers to gypsum generated from the reaction of calcium oxide with desulfurization and denitrification agents during flue gas desulfurization and denitrification processes. Currently, industrial by-product gypsum mainly originates from flue gas desulfurization and denitrification, as well as waste streams from industries such as steel and copper metallurgy, phosphate chemical production, and fertilizer manufacturing. This dataset is compiled from data derived from multiple sources. Gypsum is a by-product of this process.