Calcium Oxide

I. Building Materials Industry

Preparation of Lime Mortar and Concrete: Calcium oxide reacts with water to produce calcium hydroxide (hydrated lime). Hydrated lime can be mixed with sand, cement, etc., to make lime mortar, used for wall construction and plastering; it can also be used as an admixture in concrete to improve its workability and durability, and enhance the strength of building structures.

Production of Silicate Products: As one of the core raw materials, calcium oxide is used in the production of silicate building materials such as lime-sand bricks, aerated concrete blocks, and cement pipes. These products are lightweight, heat-insulating, and sound-insulating, and are widely used in civil and industrial construction.

Road Subgrade Treatment: Calcium oxide can be used to improve acidic soil subgrades. By adjusting the soil pH value and reducing soil moisture content, it enhances the load-bearing capacity of the subgrade, and is especially suitable for construction on damp and soft subgrades.

II. Chemical Production Field

• Manufacturing Calcium Hydroxide and Other Calcium Salts: Calcium oxide reacts fully with water to produce high-purity calcium hydroxide, which is further used in the production of bleaching powder, calcium magnesium phosphate fertilizer, calcium citrate, and other chemical products. It is also a basic raw material for the production of calcium salts such as calcium carbonate, calcium nitrate, and calcium chloride.

• As a Basic Reaction Agent: In chemical synthesis, it is used as a neutralizing agent to treat acidic wastewater and acidic raw materials. In organic synthesis, it acts as a catalyst or dehydrating agent, participating in the preparation reactions of esters, alcohols, and other compounds.

• Raw Material for Calcium Carbide Production: Calcium carbide reacts with coke in a high-temperature electric arc furnace to produce calcium carbide (calcium carbide). Calcium carbide is a core raw material for the production of acetylene gas and is widely used in welding, cutting, and organic synthesis industries.

III. Environmental Governance Field

• Acidic Wastewater Treatment: As a low-cost alkaline agent, it neutralizes acidic substances in industrial wastewater (such as electroplating wastewater, metallurgical wastewater, and chemical wastewater), adjusting the pH value to discharge standards. Simultaneously, it can precipitate heavy metal ions (such as lead, cadmium, and copper) in wastewater, reducing the risk of water pollution.

• Flue Gas Desulfurization and Denitrification: In flue gas treatment systems of coal-fired power plants and steel mills, calcium oxide reacts with sulfur dioxide and nitrogen oxides in the flue gas to produce solid products such as calcium sulfate and calcium nitrate, achieving desulfurization and denitrification and reducing the factors contributing to acid rain formation.

• Waste Incineration Treatment: Added to waste incinerators, it neutralizes acidic gases produced during incineration (such as hydrogen chloride and hydrogen fluoride), reducing the corrosiveness of the flue gas. It can also adsorb some toxic and harmful substances, improving the treatment effect of exhaust gas.

IV. Agricultural Planting Sector

• Soil Improvement: Used to improve acidic soils, adjust soil pH, improve soil aggregate structure, promote soil microbial activity, and enhance soil fertility; it also kills pathogens, insect eggs, and weed seeds in the soil, reducing crop diseases and pests.

• Preparation of Agricultural Lime Fertilizer: As a raw material for calcium fertilizer, it supplements crops with calcium, preventing calcium deficiency symptoms in fruit trees and vegetables (such as blossom-end rot in tomatoes and bitter pit in apples); it can also be mixed with other fertilizers to make compound fertilizers.

• Livestock and Poultry Disinfection: Prepared by adding water to make lime milk, it is used to disinfect the floors, walls, and manure pits of livestock farms, killing pathogenic microorganisms, reducing the risk of livestock and poultry disease transmission, and providing long-lasting disinfection at a low cost.

V. Other Fields

• Desiccant: Utilizing its strong hygroscopic properties, it is used as an industrial desiccant to dry gases or liquids such as ammonia and ethanol, especially suitable for drying in alkaline environments where molecular sieves or silica gel cannot be used.

• Metallurgical flux: Adding calcium oxide during steelmaking can lower the melting point of gangue in the ore, separate the slag from the molten iron, and improve the purity of steel; at the same time, it can desulfurize and dephosphorize, and improve the quality of steel.