Calcium carbonate is an inorganic compound with the chemical formula CaCO₃, and is a major component of limestone, marble, and other minerals. It is typically a white, odorless crystal, practically insoluble in water, and readily reacts with acids to release carbon dioxide. It is one of the most common substances on Earth, found in rocks such as aragonite, calcite, chalk, limestone, marble, and travertine, and is also a major component of the bones and shells of some animals. Calcium carbonate is also an important building material with wide industrial applications.
Flue Gas Desulfurization
In industrial sectors such as thermal power plants and steel mills, flue gas contains large amounts of sulfur dioxide, a major cause of acid rain. Calcium carbonate, as a desulfurizing agent, reacts with sulfur dioxide to form calcium sulfate, thereby achieving flue gas desulfurization and reducing sulfur dioxide emissions.
Soil Remediation
Calcium carbonate can neutralize acidic substances in the soil, increasing the soil pH, improving the acidic soil environment, and promoting plant growth.
Calcium carbonate can also react with heavy metal ions in the soil to form insoluble carbonate precipitates, reducing the migration and bioavailability of heavy metals in the soil, and mitigating heavy metal pollution of soil and groundwater.
Solid Waste Treatment
Calcium carbonate can be used as a landfill cover material, reducing the generation of leachate and lowering environmental pollution.
In the resource utilization of certain solid wastes, calcium carbonate can be used as an additive or stabilizer to improve the physical and chemical properties of the waste and increase its utilization value.
Energy Conservation and Emission Reduction: The widespread application of calcium carbonate helps reduce the use of chemical agents and lowers energy consumption and costs in processes such as wastewater treatment and flue gas desulfurization.
Using calcium carbonate for soil remediation and waste treatment can reduce the exploitation and consumption of natural resources and lower the environmental burden.