A method for manufacturing a coal additive that is added to coal as a solid fuel to microgranulate and uniformize the coal, thereby increasing the combustion area of the coal, leading to a decrease in combustion time and a reduction in unburned carbon generation. A raw material for the coal additive is prepared as a liquid phase by placing, in a container, a fermented liquid, which is an extract obtained from the incubation of fermenting bacteria (enzyme) in fruit residues, and an emulsion of metal ions and bentonite or gelrite, followed by mixing. Coal may be subjected to microgranulation and uniformization as a solid fuel by addition of the liquefied additive to the coal. The degree of coal powder is improved to increase combustion area, thereby shortening combustion time and reducing generation of unburned carbon, leading to increasing energy efficiency, which is environmentally friendly and safe and has remarkable effects.

A combustible heat source for a smoking article is provided, including carbon and a binding agent. The binding agent includes a combination of three binder components: an organic polymeric binder material, a carboxylate burn salt, and at least one non-combustible inorganic binder material. The at least one non-combustible inorganic binder material includes a sheet silicate material. Preferably, the combustible heat source further includes an ignition aid.

The invention also provides a briquette comprising: (i) a particulate material; and (ii) a binder, the binder comprising (a) at least partially saponified polyvinyl alcohol and (b) an alkali metal alkyl siliconate or polyalkylsilicic acid; wherein the particulate material is selected from a carbonaceous material, metal, metal ore, mineral waste or a mixture thereof.