Natural bitumen is known as bitumen, Gilsonite or Unitaite (from the Unitaite mountains in the US). Gilsonite is one of the derivatives of crude oil to change reaching the earth’s surface due to geoglogical changes and finding an appropriate and dry space: to changes This material is an important industrial material which is found in a limited number of countries. Iran is one of the few countries which have a high reserve of natural bitumen. Among the different provinces of Iran, Kermanshah is considered one of the richest province regarding the natural bitumen reserves.
Natural bitumen is the product of oil migration from oil reserves towards the surface layers of earth. The present crude oil in oil reserves is always under hydrostatic pressures and these pressures lead this material to be always searching for an exit. Hence, it travels through the cracks and fissures and faults in the rock towards the earth surface. The initial crude oil gradually transforms from kerosene to asphalt and finally to a material which is physically similar to pirobitumen. Then, this material solidifies so that it turns into black bitumen. The term pirobitumen has been chosen to indicate the last stage of oil maturation. bitumen is a general term for a group of combinatory material from heavy hydrocarbons which are flammable and are solved in aromatic and aliphatic solvent.
Gilsonite is a natural hydrocarbon which is a brittle and shiny material and highly brittle in case of high purity. The ore is black and its powder is chocolate brown. This material is physically and chemically similar to coal (fossil fuel) and tar (oil products). Its main difference with coal is the softening and melting properties before burning and its main difference with tar is its softening and polar molecular properties. While Gilsonite is chemically similar to asphalt, it has many important differences including the higher softening point of bitumen compared to oil-derived asphalt, which turnes Gilsonite into a unique substance.Unique properties of Gilsonite, has made it useful substance with unique physical and chemical properties in most applied industries. Nowadays, due to the unique properties of this material, more than 160 products are derived from it and the major ones are used in: ink industries, oil drilling (cementing the wells), drilling mud, foundry, optimizing special asphalts and insulation.