Calcium carbide

Some rocks can make gas.

This gas can burn. It can make bright light. People used it in old lamps.

The rock can also help grow food. It can even help make steel. It can help make things like toy cannons. Some people use it to keep moles away. This happens when the rock touches water. The gas then pushes the moles away. It is a very busy material!

Calcium carbide is a special material used in many ways.

Pure calcium carbide is a clear solid. Most kinds used in factories are grey or brown. It has a smell like garlic when it touches water.

One main use is making acetylene. This is a type of gas. When water touches calcium carbide, it lets out this gas.

People used to use this gas in carbide lamps. These lamps made a bright light for miners. Today, most people use electric lights instead.

Factories also use it to make fertilizer. They mix it with nitrogen at high heat. This makes calcium cyanamide, which helps plants grow. Calcium carbide also helps make steel. It can remove sulfur from iron.

Making this material takes a lot of heat. Workers use an electric arc furnace. This is a large machine that uses electricity. They mix lime and coke inside to make the carbide. This way of making it was found in 1892. It is still used the same way today.

Calcium carbide is a very useful chemical compound.

Pure calcium carbide is a clear, colorless solid. Most versions used in industry look grey or brown. These pieces usually contain about 80 to 85 percent calcium carbide. The rest is made of other things like calcium oxide or carbon. If the material touches even a little bit of water, it smells like garlic. This material is important because it helps make many other things. It is used to create gas, fertilizer, and even steel.

There are many ways that this material works in the world. One common way is by making acetylene gas. When water touches calcium carbide, it creates acetylene and calcium hydroxide.

This gas can be burned to make light. Another way it works is through heat and nitrogen. If you mix calcium carbide with nitrogen at a high temperature, it forms calcium cyanamide. This is a substance called nitrolime that helps plants grow as fertilizer. It can also be used in steelmaking to remove sulfur from iron.

People discovered how to make this material a long time ago. In 1892, T. L. Willson found a way to produce it. H. Moissan also discovered this method in that same year. To make it, factories use a huge machine called an electric arc furnace. This furnace uses graphite electrodes to create extreme heat. This heat is much higher than what a normal fire can reach. This specific method of making carbide has not changed since 1892.

History shows how important this discovery was for industry. In the United States, making this was easier because of cheap power from Niagara Falls. In 1899, a man named Josef Kranz opened a huge factory in Bosnia and Herzegovina. His company was called "Bosnische-Elektrizitäts AG." To run this factory, they built a power station on the Pliva river. This station had a capacity of 8 MW. It was the first power station like that in Southeast Europe.

You can see how this science connects to things we use every day. Long ago, miners used carbide lamps to see in dark tunnels. These lamps were brighter than candles, but they could be dangerous in coal mines. Today, most people use electric lights or LED lights instead. You might also see calcium carbide used in toy cannons. In the Netherlands, people even use it for New Year's Eve traditions. It can even be used to help find the moisture in soil.

Calcium carbide is a chemical compound with the formula CaC2. It is also known as calcium acetylide. This substance is highly important in modern industry. It serves as a primary source for creating acetylene gas. It also helps produce calcium cyanamide, which is used in farming.

Pure calcium carbide is a colorless solid. However, the technical-grade version used in factories is usually grey or brown. This industrial version is typically 80% to 85% pure calcium carbide. The remaining part contains substances like calcium oxide, calcium phosphide, and calcium sulfide. If this material touches even a tiny amount of moisture, it gives off a strong smell like garlic.

To understand its structure, we look at how its atoms are arranged. Calcium carbide is a calcium salt of acetylene. It consists of calcium cations and acetylide anions. At room temperature, it often forms a distorted rock-salt structure. This means the units lie parallel to one another. There are also three different polymorphs, or structural forms, that appear at room temperature. These include a tetragonal structure and two different monoclinic structures. This specific atomic arrangement allows it to react predictably with other elements.

Industrial production of calcium carbide follows a very specific process. It is made in an electric arc furnace. This furnace uses a mixture of lime and coke. The reaction requires extremely high temperatures to work. It is an endothermic reaction, meaning it must absorb heat to proceed. This process requires 427 kJ/mol of energy. Because traditional combustion cannot reach such high temperatures, manufacturers use graphite electrodes. These electrodes create an electric arc to provide the necessary heat. This heat also drives off carbon monoxide during the reaction. This manufacturing method has remained the same since its invention in 1892.

Once the carbide is produced, it undergoes further processing. The material is crushed into small lumps. These lumps can range from a few millimeters to 50 millimeters in size. The impurities in the mixture tend to concentrate in the finer, smaller pieces. Scientists check the quality of the carbide through an assay. They do this by measuring how much acetylene gas is produced during hydrolysis. Hydrolysis is the process of reacting the substance with water. For example, German standards require coarse fractions to produce 300 L/kg of acetylene at 101 kPa pressure.

The history of calcium carbide is tied to the Industrial Revolution. Two men discovered the electric arc furnace method in 1892. T. L. Willson and H. Moissan discovered it independently. In the United States, production grew because of cheap hydroelectric power from Niagara Falls. In 1899, Josef Kranz opened a massive factory in Jajce, Bosnia and Herzegovina. His company was called "Bosnische-Elektrizitäts AG." To power this factory, an 8 MW hydroelectric station was built on the Pliva river. This was the first power station of its kind in Southeast Europe.

Calcium carbide has many practical applications. Its most famous use is producing acetylene gas. Friedrich Wöhler discovered in 1862 that water reacts with calcium carbide to create acetylene and calcium hydroxide.

This gas is used in many ways. In China, it is a major raw material for making polyvinyl chloride. In other parts of the world, acetylene is made from methane instead. Calcium carbide is also used to make calcium cyanamide, or nitrolime. This is a vital fertilizer for crops. In steelmaking, it helps remove sulfur from iron and acts as a deoxidizer.

We can also see its history in older technologies like carbide lamps. These lamps work by dripping water onto the carbide to create burning acetylene gas.

They provided a brighter light than candles for miners. However, they were dangerous in coal mines because the gas could ignite methane. Today, most miners use electric or LED lights. You might still see carbide lamps used by cavers or in silver mines in Bolivia. Other uses include making toy cannons and even measuring moisture in soil. In a closed cylinder, the gas released from the reaction helps scientists calculate water content.