A process and an apparatus are disclosed for improved recovery of metal from hot and cold dross, wherein a dross-treating furnace is provided with a filling material with good capacity to store heat. This filling material is preheated to a desired temperature by injection of an oxidizing gas to burn non-recoverable metal remaining in the filling material after tapping of the recoverable metal contained in the dross and discharging of the treatment residue. When dross is treated in such furnace, the heat emanating by conduction from the filling material is sufficient to melt and separate the recoverable metal contained in the dross, without addition of an external heat source, such as fuel or gas burners, plasma torches or electric arcs and without use of any salt fluxes. Furthermore, the recovered metal being in the molten state can be fed to the molten metal holding furnace without cooling the melt; in addition, the non-use of fluxing salt for the treatment means that the non-contaminated residue can be used as a cover for the electrolytic cells in the case of aluminum. In the case of zinc dross, the residue is a valuable zinc oxide by-product very low in contaminants.

Disclosed are adjustable kiln flights for rotary kilns and associated methods. The kiln flight includes a base configured to be secured to a rotary kiln surface of a rotary kiln. In some aspects, the kiln flight includes a flight body rotatably supported on the base such that an angular orientation of the flight body is adjustable. In various examples, the kiln flight includes a height adjuster movably supported relative to the base such that a height of the kiln flight is adjustable. A method of controlling a rotary kiln with the adjustable kiln flight includes supporting a kiln flight on a base that is secured to an inner kiln surface of a rotary kiln, and adjusting at least one of the angular orientation of the kiln flight or the height of the kiln flight.

Disclosed are adjustable kiln flights for rotary kilns and associated methods. The kiln flight includes a base configured to be secured to a rotary kiln surface of a rotary kiln. In some aspects, the kiln flight includes a flight body rotatably supported on the base such that an angular orientation of the flight body is adjustable. In various examples, the kiln flight includes a height adjuster movably supported relative to the base such that a height of the kiln flight is adjustable. A method of controlling a rotary kiln with the adjustable kiln flight includes supporting a kiln flight on a base that is secured to an inner kiln surface of a rotary kiln, and adjusting at least one of the angular orientation of the kiln flight or the height of the kiln flight.

The present invention relates to a rotary kiln for burning carbonate-containing material, in particular limestone or dolomite, including a rotary tube with an inlet end for the feeding of the material to be burned and an outlet end for the discharging of the burned material, the rotary tube having an inlet zone at its inlet end and an outlet zone at its outlet end wherein a preheating zone and a combustion zone are arranged between the inlet zone and outlet zone, the rotary kiln being characterized according to the invention in that in the inlet zone of the rotary tube at least one projection is provided, the at least one projection having at least one sliding surface inclined to the longitudinal axis of the rotary tube for conveying the material to be burned from the inlet zone into the preheating zone. The present invention further relates to a method for burning carbonate-containing material, in particular limestone or dolomite.

The present invention relates to a rotary kiln for burning carbonate-containing material, in particular limestone or dolomite, including a rotary tube having an inlet end for feeding in the material to be burned and an outlet end for discharging the burned material; and a calciner unit which is arranged in the region of the outlet end, the rotary tube having an inlet zone at its inlet end and having an outlet zone at its outlet end, with a preheating zone and a burning zone being arranged between the inlet zone and the outlet zone in the transport direction of the material. The rotary kiln is characterized according to the invention in that a plurality of projections are arranged in the preheating zone of the rotary tube, the projections being arranged in groups one behind the other and substantially in parallel with the longitudinal axis of the rotary tube, with projections of adjacent groups of projections that are adjacent in the circumferential direction of the rotary tube being offset relative to one another in the longitudinal direction of the rotary tube such that spiral transport paths for the material to be burned are formed in the preheating zone. The present invention further relates to a method for burning carbonate-containing material, in particular limestone or dolomite.

The present invention relates to a rotary kiln for burning carbonate-containing material, in particular limestone or dolomite, including a rotary tube having an inlet end for feeding the material to be burned and an outlet end for discharging the burnt material, and a burner unit arranged in the region of the outlet end, the rotary tube having an inlet zone at its inlet end and an outlet zone at its outlet end, a preheating zone and a combustion zone being arranged between the inlet zone and outlet zone in the direction of transport of the material. The rotary kiln is characterized according to the invention in that at least one projection is arranged in the outlet zone of the rotary tube, the at least one projection having a contour tapering in the direction of rotation of the rotary tube. The present invention further relates to a method for burning carbonate-containing material, in particular limestone or dolomite.

A rotary tube apparatus for cooling or heating flowable granular bulk materials, in particular a sectional cooler (8) for cooling a flowable granular solid material, with structures mounted on its walls for increasing the thermal conduction, characterized in that the structures include hollow tubes (10).

Disclosed are adjustable kiln flights for rotary kilns and associated methods. The kiln flight includes a base configured to be secured to a rotary kiln surface of a rotary kiln. In some aspects, the kiln flight includes a flight body rotatably supported on the base such that an angular orientation of the flight body is adjustable. In various examples, the kiln flight includes a height adjuster movably supported relative to the base such that a height of the kiln flight is adjustable. A method of controlling a rotary kiln with the adjustable kiln flight includes supporting a kiln flight on a base that is secured to an inner kiln surface of a rotary kiln, and adjusting at least one of the angular orientation of the kiln flight or the height of the kiln flight.

Disclosed are adjustable kiln flights for rotary kilns and associated methods. The kiln flight includes a base configured to be secured to a rotary kiln surface of a rotary kiln. In some aspects, the kiln flight includes a flight body rotatably supported on the base such that an angular orientation of the flight body is adjustable. In various examples, the kiln flight includes a height adjuster movably supported relative to the base such that a height of the kiln flight is adjustable. A method of controlling a rotary kiln with the adjustable kiln flight includes supporting a kiln flight on a base that is secured to an inner kiln surface of a rotary kiln, and adjusting at least one of the angular orientation of the kiln flight or the height of the kiln flight.

A method and system (100) is provided for continuous recycling of waste plastic feedstock into liquid fuels. The method includes sending the feedstock into a rotary retort vessel at an input end of the rotary retort vessel. The feedstock is received on either sides of a partition structure, wherein the partition structure connects the input end of the rotary retort vessel to an output end of the rotary retort vessel. The feedstock is pyrolized in the rotary retort vessel, wherein the feedstock produces gaseous byproducts and non-gaseous byproducts. The byproducts are moved towards the output end of the rotary retort vessel, wherein the movement is facilitated by declination of the rotary retort vessel and the one or more partition structures. The non-gaseous byproducts are continuously removed from the rotary retort vessel.