Gilsonite
Some types of bitumen in nature, due to the gradual conversion of crude oil and evaporation of its volatile matter, have come about over many years. This Bitumen is called Gilsonite or Natural bitumen and its durability is more than oil tar. It may exist purely in nature (lake bitumen), or extracted from mines (mineral tar).
It is applying for road construction and making asphalt. Natural Bitumen also uses in making paints, insulation and drilling as one of fluid lost control agent.
Iran Chemical Mine, supplying Mineral Bitumen or in some categories by different Ash grades:
15-20%
20-25%
