What remains after the combustion of coal?

When coal undergoes combustion, it primarily consists of carbon, hydrogen, sulfur, and various trace elements. During the combustion process, the carbon reacts with oxygen to produce carbon dioxide and water vapor. The hydrogen also reacts with oxygen to form water vapor. The sulfur compounds can produce gaseous emissions that contain sulfur dioxide.

However, not all components of coal are consumed during combustion. The inorganic minerals that are present in coal do not burn and instead remain as a residue, which is referred to as inorganic ash. This ash primarily consists of silica, alumina, and various metal oxides.

The presence of inorganic ash is significant because it can impact the efficiency of combustion and the quality of emissions. It can also cause wear on equipment and affect operations by requiring disposal or recycling. Understanding the residuals from coal combustion, including inorganic ash, is crucial for managing environmental impacts and optimizing combustion processes in mining operations.