natural bitumen is completely dissolve in the ordinary solvents such as gasoline or benzol unless, for instance, it is refluxed with these solvents at a high temperature. This is probably due to the fact that natural bitumen is highly colloidal and therefore, tends to resist complete smooth solution.
natural bitumen having a melting point of approximately from 150C up to 220. (Ball and Ring method) and ash of solved and, therefore, is poorly suited as a saturating material for brake linings for instance, where a considerable proportion of colloidal material is left on the surface when impregnation is attempted.
Natural asphalt or mineral bitumen is a sedimentary rock formed in wide, low-lying equatorial swamps crossed by large rivers and covered by forests of primitive animals. Here, the remains of animals saved from biodegration and oxidation by mud and water. natural bitumen is usually black in colour but sometimes it occurs as a brownish-black colour. There are four broad ranks or types of natural bitumen depending upon its age. Commencing with the youngest and lowest carbon content.
natural bitumen being a natural material varies in composition depending upon its origin, history of formation and the geographical region and the presence of other minerals such as sulphur, phosphorus and others. So little wonder natural bitumen does not have a specific composition. In general it is Hydro carbon and some of the carbon will be in the form of volatiles which evaporate readily as in natural bitumen. There is also inert material either mineral or within the carbon which forms ash. Complex chemical compounds are also formed during natural bitumen formation and some of these may have toxic properties. natural bitumen technology is therefore quite complex and important in its utilisation.
Regards toxicity and environmental pollution, present day technology is well developed in reducing impacts to within acceptable levels. Please dont worry to use it.