The present invention relates to a method for producing aggregates from concrete residues which are not used for construction purposes or, more generally, from cement mixtures which are unused for any reason and returned to the production facility in the truck mixer. The present invention also relates to the material obtained by said process and its use as an aggregate for concrete production or other applications.

Apparatus uses engineered collection media to recover mineral particles in a slurry. The apparatus has a tumbler cell and a rotation device to rotate the tumbler cell. The tumbler cell has a container to hold a mixture of the engineered media and the slurry containing the mineral particles. The container is turned such that at least part of the mixture in the upper part of the container is caused to interact with at least part of the mixture in the lower part of the container. As such, the contact between the engineered media and the mineral particles is enhanced. The surfaces of the engineered media are functionalized with a chemical having molecules to attract the mineral particles to the surfaces so as to form mineral laden media. After the mineral laden media are discharged from the tumbler cell, the mineral particles can be separated from the engineered media by stripping.

Apparatus uses engineered collection media to recover mineral particles in a slurry. The apparatus has a tumbler cell and a rotation device to rotate the tumbler cell. The tumbler cell has a container to hold a mixture of the engineered media and the slurry containing the mineral particles. The container is turned such that at least part of the mixture in the upper part of the container is caused to interact with at least part of the mixture in the lower part of the container. As such, the contact between the engineered media and the mineral particles is enhanced. The surfaces of the engineered media are functionalized with a chemical having molecules to attract the mineral particles to the surfaces so as to form mineral laden media. After the mineral laden media are discharged from the tumbler cell, the mineral particles can be separated from the engineered media by stripping.

Fine coal is cleaned of its mineral matter impurities and dewatered by mixing the aqueous slurry containing both with a hydrophobic liquid, subjecting the mixture to a phase separation. The resulting hydrophobic liquid phase contains coal particles free of surface moisture and droplets of water stabilized by coal particles, while the aqueous phase contains the mineral matter. By separating the entrained water droplets from the coal particles mechanically, a clean coal product of substantially reduced mineral matter and moisture contents is obtained. The spent hydrophobic liquid is separated from the clean coal product and recycled. The process can also be used to separate one type of hydrophilic particles from another by selectively hydrophobizing one.

Fine coal is cleaned of its mineral matter impurities and dewatered by mixing the aqueous slurry containing both with a hydrophobic liquid, subjecting the mixture to a phase separation. The resulting hydrophobic liquid phase contains coal particles free of surface moisture and droplets of water stabilized by coal particles, while the aqueous phase contains the mineral matter. By separating the entrained water droplets from the coal particles mechanically, a clean coal product of substantially reduced mineral matter and moisture contents is obtained. The spent hydrophobic liquid is separated from the clean coal product and recycled. The process can also be used to separate one type of hydrophilic particles from another by selectively hydrophobizing one.

A process for improving the dewatering characteristic of tailings is provided comprising adding flue-gas desulfurization (FGD) solids, produced when using calcium oxide to remove sulfur dioxide from flue gas or emissions, to the tailings.

A process for improving the dewatering characteristic of tailings is provided comprising adding flue-gas desulfurization (FGD) solids, produced when using calcium oxide to remove sulfur dioxide from flue gas or emissions, to the tailings.

The present invention relates to a method for producing aggregates from concrete residues which are not used for construction purposes or, more generally, from cement mixtures which are unused for any reason and returned to the production facility in the truck mixer. The present invention also relates to the material obtained by said process and its use as an aggregate for concrete production or other applications.

The present invention relates to a method for producing aggregates from concrete residues which are not used for construction purposes or, more generally, from cement mixtures which are unused for any reason and returned to the production facility in the truck mixer. The present invention also relates to the material obtained by said process and its use as an aggregate for concrete production or other applications.

A modified selective recirculation circuit has a loading stage, a stripping stage and a filtering stage for use in processing a feed stream or slurry containing mineral particles. The stripping stage forms a first loop with the loading stage, a second loop with the filtering stage. The loading stage has a loading mixer and a loading washing screen. The stripping stage has a stripping mixer and a stripping washing screen. The loading mixer receives the slurry and causes barren media in the circuit to contact with the slurry so that the mineral particles in the slurry are loaded onto the barren media. The media is directed to the stripping stage where the mineral particles are removed from the media. The barren media is recycled to the loading stage. The stripping solution recovered from the filtering stage is returned to the stripping stage and the mineral particles are discharged as concentrate.