LANDMARK PROJECT ON MINING
Mining is the extraction of valuable minerals or other geological materials from the earth, usually from an ore body, lode, vein, seam, reef or placer deposit.
BITUMEN
Bitumen is a black viscous mixture of hydrocarbons obtained naturally or as a residue from petroleum distillation. At the temperatures normally encountered in natural deposits, bitumen will not flow; in order to be moved through a pipe, it must be heated and, in some cases, diluted with lighter oil. It owes its density and viscosity to its chemical composition—mainly large hydrocarbon molecules known as asphaltenes and resins, which are present in lighter oils but are highly concentrated in bitumen. By far most refined bitumen is used in paving asphalt and roofing tiles, as is a large amount of natural bitumen. Bituminous materials or asphalts are extensively used for roadway construction, primarily because of their excellent binding characteristics and water proofing properties and relatively low cost. Bituminous materials consists of bitumen which is a black or dark coloured solid or viscous cementitious substances consists chiefly high molecular weight hydrocarbons derived from distillation of petroleum or natural asphalt, adhesive properties, and is soluble in carbon disulphide. Tars are residues from the destructive distillation of organic substances such as coal, wood, or petroleum and are temperature sensitive than bitumen.
Production of Bitumen
Bitumen is the residue or by-product when the crude petroleum is refined. Green Globe USA LLC makes use of a wide variety of refinery processes, such as the straight distillation process, solvent extraction process etc. to produce bitumen of different consistency and other desirable properties.
Vacuum steam distillation of petroleum oils
Here, the crude oil is heated and is introduced into a large cylindrical still. Steam is introduced into the still to aid in the vapourisation of the more volatile constituents of the petroleum and to minimise decomposition of the distillates and residues. The volatile constituents are collected, condensed, and the various fractions stored for further refining, if needed.
DIFFERENT FORMS OF BITUMEN
Cutback bitumen
In cutback bitumen suitable solvent is used to lower the viscosity of the bitumen. From the environmental point of view also cutback bitumen is preferred. The solvent from the bituminous material will evaporate and the bitumen will bind the aggregate. Cutback bitumen is used for cold weather bituminous road construction and maintenance. The distillates used for preparation of cutback bitumen are naphtha, kerosene, diesel oil, and furnace oil.
Bituminous primers
In bituminous primer the distillate is absorbed by the road surface on which it is spread. The absorption therefore depends on the porosity of the surface. Bitumen primers are useful on the stabilised surfaces and water bound macadam base courses.
Modified Bitumen
Certain additives or blend of additives called as bitumen modifiers can improve properties of Bitumen and bituminous mixes. Bitumen treated with these modifiers is known as modified bitumen. Polymer modified bitumen (PMB)/ crumb rubber modified bitumen (CRMB) should be used only in wearing course depending upon the requirements of extreme climatic variations.
TESTS ON BITUMEN
In Green Globe USA LLC there are a number of tests we use to assess the properties of bituminous materials. The following tests are usually conducted to evaluate different properties of bituminous materials’ PENETRATION TEST, DUCTILITY TEST, SOFTENING POINT TEST, SPECIFIC GRAVITY TEST, VISCOSITY TEST, FLASH AND FIRE POINT TEST