Abstract: Crushed sulfur is melted by and is mixed with hot liquid asphalt at a manufacturing plant, after which the mixture is formed into sulfur-asphalt pellets. The sulfur added to the asphalt prevents a mass of the pellets from flowing and conglomerating at ambient temperatures. The pellets thus may be shipped in bulk form and without special temperature control from the manufacturing plant site to a remote site where the pellets are mixed with heated aggregate and are melted to form a sulfur-extended bituminous concrete paving composition for application to a roadway. By mixing a fine mineral filler such as calcium hydroxide with the crushed sulfur and the hot liquid asphalt at the manufacturing plant, temperature-stable pellets may be produced while using a lower ratio of sulfur to asphalt in the mixture. If desired, aggregate also may be added to the mixture at the manufacturing plant to form briquettes and avoid the need of mixing the pellets with aggregate at the paving site.

Abstract: A drum-type drier and/or mixer in which particulate material such as aggregate or recycled asphalt is introduced into the forward end of the drum. A burner at the rear end of the drum directs its flame forwardly through an elongated firing tube which extends from the rear end of the drum toward the forward end thereof. The hot gases discharged from the tube strike a baffle, are deflected into an annular chamber between the tube and the drum and then flow rearwardly through the chamber to an exhaust stack. The particulate material also is advanced rearwardly through the chamber and, during such advance, is heated (1) indirectly by the hot gases flowing forwardly through the firing tube and (2) directly by the hot gases deflected into and flowing rearwardly through the chamber.