What is Calcium carbide?

Calcium carbide, also known as calcium acetylide, is an important industrial chemical widely used in the production of acetylene gas and calcium cyanamide. Its reactive properties make it essential in various manufacturing and chemical processing applications.

What Is Calcium Carbide Used For?
Calcium carbide has a wide range of industrial applications due to its ability to release acetylene gas and its strong reactivity. The primary uses of calcium carbide include:

• Acetylene Generation: Calcium carbide is mainly used to produce acetylene gas, which serves as a reducing agent and is commonly used in carbide lamps and fruit ripening processes.

• Fertilizer Production: It plays a key role in manufacturing chemical fertilizers, particularly calcium cyanamide.

• Steelmaking: In steel production, calcium carbide helps increase the scrap-to-liquid iron ratio and contributes to more efficient melting processes.

• Deoxidation in Ladle Treatment: It is widely used as an effective deoxidizer in ladle metallurgy to improve steel quality.

• Soil Moisture Determination: Calcium carbide is also used in testing equipment to determine soil moisture content accurately.

• Desulfurization: It aids in removing sulfur impurities from pig iron, cast iron, and steel during metal processing.

• Signal Flares: Combined with calcium phosphide, calcium carbide is used in floating and self-igniting naval signal flares.

• Pest Repellent: It can also be used as an effective mole repellent in agricultural settings.

What Is the Chemical Formula of Calcium Carbide?
The chemical formula of calcium carbide is CaC₂.

Is Calcium Carbide Harmful to Life?
Yes, calcium carbide can be harmful if proper safety precautions are not followed. Direct contact with the skin may cause irritation or chemical burns, while exposure to the eyes can result in severe damage and potentially permanent injury. Inhalation of small amounts may irritate the respiratory tract, and higher levels of exposure can lead to fluid accumulation in the lungs, potentially causing pulmonary edema—a serious medical condition. Additionally, calcium carbide is considered potentially carcinogenic and should be handled with extreme care, avoiding unnecessary exposure.

Where Is Calcium Carbide Found?
In industrial settings, calcium carbide is produced by reacting lime (calcium oxide) with coke in an electric arc furnace at extremely high temperatures—typically around 2200°C. It can also be obtained as a byproduct during the smelting of calcium–silicon alloys.

What Does Calcium Carbide Look Like?
Calcium carbide typically appears as grayish-black, hard lumps or as a crystalline powder, and it emits a distinctive garlic-like odor due to impurities. In its pure form, calcium carbide is colorless, though industrial-grade material often contains trace compounds that affect its color and smell.

What Are the Hazardous Effects of Calcium Carbide?
Although calcium carbide itself is non-combustible, it becomes extremely hazardous when it comes into contact with water or moisture. Upon exposure to water, it reacts vigorously to produce flammable acetylene gas along with other toxic gases, creating a significant fire and explosion risk. Even in humid air, sealed containers of calcium carbide may build up pressure and rupture violently, releasing dangerous fumes and posing serious safety threats.

What Precautionary Measures Should Be Taken When Handling Calcium Carbide?
Calcium carbide must be handled with extreme care to prevent hazardous reactions and unsafe conditions. Only trained and qualified personnel should manage its storage and use. Strict industrial hygiene practices must be followed at all times, including the use of appropriate protective gear. Personal protective equipment (PPE) should be made from materials that are resistant to chemical degradation and cannot be penetrated by calcium carbide. Additionally, the chemical should always be kept dry and stored in tightly sealed containers to prevent accidental contact with moisture.

What Happens If Calcium Carbide Is Heated?
Calcium carbide undergoes highly exothermic reactions, especially when it comes into contact with water, releasing a significant amount of heat along with acetylene gas. However, when calcium carbide is heated to high temperatures in the presence of nitrogen, it reacts to form calcium cyanamide, an important intermediate used in the production of fertilizers. This high-temperature reaction is a key industrial process in nitrogen-based fertilizer manufacturing.

Is Calcium Carbide a Soluble Compound?
Calcium carbide is not soluble in water. Instead, it reacts vigorously and decomposes upon contact with water, producing acetylene gas and calcium hydroxide. This reaction is highly exothermic and requires careful handling to avoid hazardous conditions.

Where Can I Buy Calcium Carbide?
Calcium carbide is available for purchase at Camachem. The product can be supplied in large quantities and shipped in iron drums of various capacities to meet industrial requirements. Camachem has extensive experience exporting calcium carbide to clients worldwide, ensuring reliable supply and professional logistics support.

How Much Does Calcium Carbide Cost?
The price of calcium carbide varies depending on factors such as raw material costs, logistics, production conditions, and market demand. On average, the cost is approximately $150 per tonne, though prices may fluctuate based on order volume and regional supply conditions.

What Is the pH of Calcium Carbide?
Calcium carbide is a highly basic compound, exhibiting a pH of approximately 12.4 when it reacts with water to form calcium hydroxide. Due to its strong alkalinity, it is sometimes used in acid-neutralization applications.

Is Calcium Carbide an Electrolyte Compound?
Calcium carbide itself is not considered an electrolytic compound, as it does not dissolve in water to produce ions. However, it can serve as an anode material in certain specialized industrial applications.

Can Calcium Carbide Be Disposed of Down the Drain?
No. Calcium carbide should never be disposed of down the drain because it reacts with water to release flammable acetylene gas and poses environmental risks. Any unused material should be reused whenever possible. In the event of disposal, it must be sealed and handled according to federal, state, and local regulations to ensure safe and compliant waste management.

What Is the Difference Between Calcium Carbide and Calcium Carbonate?
Calcium carbide and calcium carbonate differ significantly in appearance, chemical behavior, and applications:

• Calcium carbide is a dark, crystalline powder that reacts violently with water to produce acetylene gas.

• Calcium carbonate is a white, water-insoluble compound, commonly found in limestone, chalk, and marble.

• Their uses also vary greatly: calcium carbide is mainly used for acetylene production and metallurgical applications, whereas calcium carbonate is widely used in construction materials, pharmaceuticals, plastics, and agriculture.