A mixing drum includes a body defining a head aperture and a discharge aperture opposite the head aperture, a head coupled to the body and extending across the head aperture, and a mixing element positioned within the volume and coupled to the body. The head and the body define a volume. The body is formed from at least a first section and a second section. The first section overlaps the second section.

A mixing drum includes a body defining a head aperture and a discharge aperture opposite the head aperture, a head coupled to the body and extending across the head aperture, a bearing member coupled to the body and defining a bearing surface surrounding the body, and a mixing element positioned within the volume and coupled to the body. The head and the body define a volume configured to contain a fluid mixture. The mixing element is configured to drive the fluid mixture toward the head when the drum is rotated in a first direction. The mixing element is configured to drive the fluid mixture towards the discharge aperture when the mixing drum is rotated in a second direction opposite the first direction. The head is made from a first material, and the body is made from a second material having a lesser density than the first material.

Method and apparatus to facilitate recycling of at least one fraction of bitumen-containing materials. This can be accomplished by dissolving the at least one fraction, for example, maltenes or asphaltenes in roofing shingles, into at least one solvent. In one aspect, the apparatus comprises a dissolution vessel, a tumbler positioned therein, and at least one solvent distributor. The tumbler is configured to facilitate wetting the bitumen-containing materials with solvent. In a second aspect, a system comprises the apparatus, a solid-liquid separator, for example, a vibratory screen, and at least one solvent-fraction separator, for example, a flash drum. The at least one solvent can comprise one or more solvents useful to extract the at least one fraction. In a third aspect, a first fraction is extracted from the bitumen-containing materials with a first solvent composition, then a second fraction is extracted from the remaining bitumen-containing materials with a second solvent composition.

Method and apparatus to facilitate recycling of at least one fraction of bitumen-containing materials. This can be accomplished by dissolving the at least one fraction, for example, maltenes or asphaltenes in roofing shingles, into at least one solvent. In one aspect, the apparatus comprises a dissolution vessel, a tumbler positioned therein, and at least one solvent distributor. The tumbler is configured to facilitate wetting the bitumen-containing materials with solvent. In a second aspect, a system comprises the apparatus, a solid-liquid separator, for example, a vibratory screen, and at least one solvent-fraction separator, for example, a flash drum. The at least one solvent can comprise one or more solvents useful to extract the at least one fraction. In a third aspect, a first fraction is extracted from the bitumen-containing materials with a first solvent composition, then a second fraction is extracted from the remaining bitumen-containing materials with a second solvent composition.

A mixing drum includes a body defining a head aperture and a discharge aperture opposite the head aperture, a head coupled to the body and extending across the head aperture, and a mixing element positioned within the volume and coupled to the body. The head and the body define a volume. The body is formed from at least a first section and a second section. The first section overlaps the second section.

A mixing drum includes a body defining a head aperture and a discharge aperture opposite the head aperture, a head coupled to the body and extending across the head aperture, a bearing member coupled to the body and defining a bearing surface surrounding the body, and a mixing element positioned within the volume and coupled to the body. The head and the body define a volume configured to contain a fluid mixture. The mixing element is configured to drive the fluid mixture toward the head when the drum is rotated in a first direction. The mixing element is configured to drive the fluid mixture towards the discharge aperture when the mixing drum is rotated in a second direction opposite the first direction. The head is made from a first material, and the body is made from a second material having a lesser density than the first material.

A mixing drum includes a body defining a discharge aperture, a head coupled to the body opposite the discharge aperture, and a mixing element. The body includes an inner layer defining an interior surface of the body and an outer layer defining an exterior surface of the body. The head includes a connecting flange extending between the inner layer and the outer layer of the body. The head and the body define a volume. The mixing element is positioned within the volume and coupled to the body.

A method of making hot mix asphalt using recycled asphalt in which tertiary air is mixed with products of combustion at an exit of a refractory-lined chamber to produce hot controlled temperature process air, the temperature of the tertiary air being increased while the temperature of the products of combustion is decreased to adjust a temperature of the hot controlled temperature process air. Particles of the recycled asphalt are heated by exposing the particles to the hot controlled temperature process air in the rotary counter-flow dryer and mixer and moisture is removed from the recycled asphalt with the hot controlled temperature process air.