GB424415A - Improvements relating to asphaltic and bituminous compositions - Google Patents

Abstract

Fresh Florida bleaching-earth (Florida decolourizing clay), as used for refining and decolourizing in the petroleum industry and for refining mineral lubricating oils, is incorporated in bituminous and asphaltic compositions. The earth may be activated prior to use, as by heating or acid treatment or both. Examples are given showing how the addition of the earth to usual bituminous compositions results in a hardening of the latter. Thus in one example a mixture containing 9 to 11 per cent epur<\>ae, 9 to 11 residual petroleum bitumen, 5 to 6 Florida bleaching earth and 70 to 75 powdered limestone, has a hardness number 15 compared with a hardness number 30 to 40 for a mixture containing no earth but otherwise identical therewith. The petroleum bitumen and epur<\>ae are melted together and incorporated with the earth, preferably in vertical mixers. This composition is then incorporated with the limestone in horizontal mixers. This mixture may be mixed with 30 per cent of its weight of granite chippings for paving purposes. Other examples are given in which sand and natural rock asphalt are used as the principal constituents. Specification 372,755 is referred to.