How does coke melt?

Coke, which typically refers to the fuel produced from coal, undergoes several stages of transformation when subjected to high temperatures. The process of coke melting involves a series of physical and chemical changes. Here's a general description of how coke melts:

1. Dehydration: As coke is heated, the first stage involves the release of moisture and other volatile compounds. This initial process is known as dehydration, where water molecules and other gases escape, leaving behind a drier form of coke.

2. Softening and Plastic Phase: As the temperature increases further, the coke begins to soften and enter what is called the plastic phase. During this stage, the coal components start to break down, and the coke becomes more malleable. The softened coke can undergo plastic deformation, allowing it to be molded or shaped.

3. Fusion: As the temperature continues to rise, the coke reaches its fusion point, where it begins to melt and transform into a liquid state. This typically occurs at around 2500 to 3000 degrees Celsius (4532 to 5432 degrees Fahrenheit). The fused coke has a high fluidity, allowing it to flow and spread easily.

4. Gasification: At extremely high temperatures, the molten coke undergoes gasification. During this process, the coke reacts with oxygen or steam present in the surrounding environment, resulting in the formation of various gaseous products. This stage leads to the release of carbon monoxide, hydrogen, and other gases, leaving behind a solid residue known as coke ash.

It's important to note that the exact melting behavior of coke can vary depending on its composition and specific conditions, such as the heating rate, pressure, and atmosphere present during the process.