Volatile matter in coal predominantly consists of what?

Volatile matter in coal predominantly consists of gasifiable substances at high temperatures. When coal is heated, these substances can vaporize and transition into gas form. This process allows for the generation of flammable gases that can be used for energy production. The volatile matter is a crucial factor in determining the coal's combustibility and overall quality, as it affects the efficiency of combustion and energy output.

Understanding the composition of volatile matter is vital for various applications, including combustion processes in power generation and the production of chemicals. The ability of these substances to gasify indicates their potential utility in producing syngas or other refined products when coal is subjected to pyrolysis or gasification.

The other options focus on materials that do not contribute to the volatile nature of coal. Incombustible materials and non-combustible ash refer to residues that remain after combustion, while heavy metals and minerals do not represent the gasifying capability typical of volatile matter. Therefore, the correct answer highlights the key role that gasifiable substances play in the characterization and use of coal.