A process for refining sand for use as frac sand includes the steps of passing the sand through a first fines separation stage to remove fine particles of contaminant from the sand, reducing the water content of the sand (such as to less than 20%), passing the sand into an attrition scrubber unit containing moving blades to delaminate clay and other contaminants from the sand grains, passing the sand from the attrition scrubber unit through a second fines separation stage to separate fine contaminants from the sand, and dewatering the resulting sand product in a further dewatering stage.

A process for refining sand for use as frac sand includes the steps of passing the sand through a first fines separation stage to remove fine particles of contaminant from the sand, reducing the water content of the sand (such as to less than 20%), passing the sand into an attrition scrubber unit containing moving blades to delaminate clay and other contaminants from the sand grains, passing the sand from the attrition scrubber unit through a second fines separation stage to separate fine contaminants from the sand, and dewatering the resulting sand product in a further dewatering stage.

A method of separating grains of valuable minerals, precious metals, rare-earth metals, precious and semi-precious stones from natural ores in the aquatic environment by means of the phenomenon of adhesion, consecutively covering stages such as: initial separation consisting in sieving fractions up to 5000 μm from alluvial (rubble) ore or crushing primary (rock) ore to a fraction causing the separation of valuable minerals from gangue and where appropriate separating ferromagnetics from ores by means of a known method; forming the suspension by mixing the initially separated fraction of ore with liquid; adsorption of valuable minerals from the suspension on the adhesive coating and also recovering water from the process; and desorption of particles of valuable minerals from the adhesive coating; wherein lanolin or its mixtures with additives are used to form the adhesive coating in the separator, whereby, the content of lanolin in the mixture is not less than 80%.

A defined mineral phase is separated from a ground ore having several chemical phases and being present in a heterogeneous particle size distribution by classifying the ore according to a defined particle diameter into at least two fractions, a first fraction having particles essentially larger than the defined particle diameter and a second fraction having particles essentially smaller than the defined particle diameter, and the defined mineral particles of value being present in both fractions, floating the first fraction having the greater particle diameters and selecting the defined mineral particles of value in a flotation concentrate, selectively admixing the defined mineral particles of value in the fraction having the smaller particle diameters with magnetizable particles, applying a magnetic separation process to the second fraction having smaller particle diameters, and separating a concentrate with an enrichment of the defined mineral phase of value.

A defined mineral phase is separated from a ground ore having several chemical phases and being present in a heterogeneous particle size distribution by classifying the ore according to a defined particle diameter into at least two fractions, a first fraction having particles essentially larger than the defined particle diameter and a second fraction having particles essentially smaller than the defined particle diameter, and the defined mineral particles of value being present in both fractions, floating the first fraction having the greater particle diameters and selecting the defined mineral particles of value in a flotation concentrate, selectively admixing the defined mineral particles of value in the fraction having the smaller particle diameters with magnetizable particles, applying a magnetic separation process to the second fraction having smaller particle diameters, and separating a concentrate with an enrichment of the defined mineral phase of value.

A reactor system has a number of stations arranged to recover mineral particles in a slurry. The system includes a hopper to receive the slurry and barren media having hydrophobic coating to attract the mineral particles. The hopper provides a mixture of barren media and slurry to a tumbler arranged to stir the mixture in order to increase the contact between the slurry and the barren media so as to allow the mineral particles to attach to the barren media to form mineral laden media. The mineral laden media are conveyed to a rinsing station where water jets are used to wash the gangue materials off the mineral laden media. The rinsed mineral laden media are mixed with a surfactant so that the mineral particles are released from the mineral laden media. High-pressure water and air jets are then used to remove remaining surfactant from the released media.

A reactor system has a number of stations arranged to recover mineral particles in a slurry. The system includes a hopper to receive the slurry and barren media having hydrophobic coating to attract the mineral particles. The hopper provides a mixture of barren media and slurry to a tumbler arranged to stir the mixture in order to increase the contact between the slurry and the barren media so as to allow the mineral particles to attach to the barren media to form mineral laden media. The mineral laden media are conveyed to a rinsing station where water jets are used to wash the gangue materials off the mineral laden media. The rinsed mineral laden media are mixed with a surfactant so that the mineral particles are released from the mineral laden media. High-pressure water and air jets are then used to remove remaining surfactant from the released media.

A screening apparatus for grading particulate material includes a grading screen having apertures for water and/or undersize particles to pass through. The grading screen is supported on a frame mounted on a chassis via resilient linkages, and the grading screen being vibrated by a vibrating device that imparts circular or reciprocating motion to the grading screen. The grading screen is set at a predetermined slope whereby material to be graded can be delivered onto an upper end while the grading screen is vibrated to convey the material over the grading screen and to cause undersize material to pass through the apertures. Oversize material is discharged from a lower end of the screen onto a conveyor or into a collection bay or hopper. A sump beneath the grading screen receives under-sized material passing through the grading screen, and a jet pump conveys material from the sump to a dewatering screen.

A screening apparatus for grading particulate material includes a grading screen having apertures for water and/or undersize particles to pass through. The grading screen is supported on a frame mounted on a chassis via resilient linkages, and the grading screen being vibrated by a vibrating device that imparts circular or reciprocating motion to the grading screen. The grading screen is set at a predetermined slope whereby material to be graded can be delivered onto an upper end while the grading screen is vibrated to convey the material over the grading screen and to cause undersize material to pass through the apertures. Oversize material is discharged from a lower end of the screen onto a conveyor or into a collection bay or hopper. A sump beneath the grading screen receives under-sized material passing through the grading screen, and a jet pump conveys material from the sump to a dewatering screen.

Disclosed is an underground coal preparation process adopting a water medium, comprising: feeding exploited raw coal into a Φ25 mm raw coal classifying screen for screening; performing dry coal preparation on a classifying screen oversize product with a particle size greater than 25 mm and feeding a classifying screen undersize product with a particle size less than 25 mm into a special underground compact jigging machine for sorting to obtain jigging machine overflow clean coal, jigging middling coal and jigging gangue; screening and dewatering the jigging machine overflow clean coal to obtain a clean coal product, and screening and dewatering the jigging middling coal to obtain a middling coal product, sorting slime water to be sorted and generated during sorting to obtain coarse clean coal slime and coarse middling coal slime, and performing circulating water treatment on a final liquid.