A wide-size-fraction flotation system and process includes feeding coal slime to be floated into a stirrer, adding water to the floating coal slime in the stirrer, stirring, then feeding same into a grading cyclone through a first feeding pump for pre-grading; after grading of the coal slime in the grading cyclone, feeding overflow in the grading cyclone into a flotation column through a second feeding pump for flotation, discharging flotation tailings through an underflow port of the flotation column, collecting flotation concentrates through an overflow port of the flotation column and feeding same into a bubble generator through a fourth feeding pump, and the flotation concentrates passing through the bubble generator and being fed from the bottom of a hydraulic flotation machine; and feeding underflow in the grading cyclone into the hydraulic flotation machine through a third feeding pump, for flotation and recovery.

A clean coal production system and method for treating coal refuse (waste) resulted from coal mining or coal washing plants by extracting substantial remaining coal components from said coal refuse (waste) and turning them into clean (fine) coal products of much higher market value wherein the necessary water usage is recovered, recycled, and reused in a closed setting (ecosystem) to minimize environmental concerns.

Disclosed is an underground coal preparation process adopting a water medium, comprising: feeding raw coal into a special underground compact jigging machine to discharge overflow clean coal being dewatered through a φ1 mm fixed screen and screened through a φ13 mm classifying screen, and dewatering powder clean coal with a particle size less than 13 mm to obtain powder clean coal and a centrifugate; grading jigging middling coal by means of a φ13 mm classifying screen into block middling coal and powder middling coal, and dewatering the powder middling coal to obtain powder middling coal and a centrifugal liquid; and sending produced coal slime water to a water medium classifying and separation cyclone, and the obtained coarse middling coal slime and coarse clean coal slime respectively passing through a coarse middling and clean coal slime sieve bends, and then being dewatered.

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.

The present invention proposes a coal and gangue separation device, including a first supporting seat, a guide part and multiple material bins. The guide part is hinged with the first supporting seat; the guide part rotates in a vertical direction; and inlets of the plurality of material bins are sequentially distributed on a rotation track of a movable end of the guide part. In the coal and gangue separation device of the present invention, the high-pressure airflow of a high-pressure nozzle does not directly act on the materials, but on grate bar driving mechanisms; and cantilever grate bars are driven to rotate by the grate bar driving mechanisms so as to directionally discharge the mineral aggregate. Therefore, the gangue can accurately enter a gangue collection bin; and the clean coal can accurately enter a clean coal collection bin.

A process for cleaning and dewatering hydrophobic particulate materials is presented. The process is performed in in two steps: 1) agglomeration of the hydrophobic particles in a first hydrophobic liquid/aqueous mixture; followed by 2) dispersion of the agglomerates in a second hydrophobic liquid to release the water trapped within the agglomerates along with the entrained hydrophilic particles.

The present disclosure provides a hierarchical separating and grading method of coal gangue, and belongs to the technical field of coal gangue treatment and resource utilization. According to differences in the composition and properties of coal gangue, especially differences in Hardgrove grindability index (HGI), the present disclosure performs hierarchical crushing and screening to separate coal gangue into coal, sand, stone and soil. The coal can be used as a fuel for a coal gangue power plant or as an ordinary fuel. The sand and stone can be used to prepare manufactured sand and stone. The soil can replace loess for filling or preparing a building material. Obviously, by separating coal gangue into different components through hierarchical separating and grading, the present disclosure can achieve all-components utilization and effective reduction of the coal gangue.

The present disclosure relates to a green method for producing and exploiting multiple nano-carbon polymorphs from coal commonly known as anthracite, meta-anthracite, and semi-graphite. The method disrupts the prevalent environmentally unfriendly practices of burning coal with poor profitability and sustainability because the method yields an unexpectedly rich mixture of high-performance nano-materials, comprising carbon nano-fibers, carbon nano-tubes, carbon nano-onions, nano-graphite-plates, and nano-graphene-disks, by simply mechanically-comminuting coal to nano-size, with minimal sorting efforts. The resulting total-yield of nano-carbon polymorphs is over 50% by weight from properly selected coal. Innovative means are added to the prevalent comminution and sorting practices to further reduce energy and chemical consumption. More importantly, the method also refines the comminution and sorting details for producing the best custom-made formulations. This holistic engineering approach eliminates unnecessary separation and sorting steps because a custom-made formulation typically requires blending the sorted components. Formulations with mixed nano-carbon polymorphs are engineered as new and high-valued-added composite ingredients to critically raise the performance of cement-based, polymer-based, and metal-based composites.

The present invention proposes a coal and gangue separation device, including a first supporting seat, a guide part and multiple material bins. The guide part is hinged with the first supporting seat; the guide part rotates in a vertical direction; and inlets of the plurality of material bins are sequentially distributed on a rotation track of a movable end of the guide part. In the coal and gangue separation device of the present invention, the high-pressure airflow of a high-pressure nozzle does not directly act on the materials, but on grate bar driving mechanisms; and cantilever grate bars are driven to rotate by the grate bar driving mechanisms so as to directionally discharge the mineral aggregate. Therefore, the gangue can accurately enter a gangue collection bin; and the clean coal can accurately enter a clean coal collection bin.

A system and process for closed loop system for removing particulate from a coal fired power wash water waste stream comprising a submerged flight conveyor for receiving used wash water, a bleed line for diverting wash water from the submerged flight conveyor, a filter for removing particulate from the diverter wash water, and pumps to recirculate the wash water on a loop through the system.