In coal-fired power plant, where coats would be pulverized by the coal mill and fed into boiler with hot airs in a high speed. this pulverized coal will be immediately combusted in the boiler at the high temperature range of 1,500±200℃ beyond the melting point of most mineral in the coal .
　　This combustion remains unburned ash at last ,which explains approximately 26-50 wt％of hard coal and 8-15wt％of  bituminous coal. This ash will be extracted out in forms of Bottom Ash, Eco.& APH Ash and ESP Fly Ash according to the places gathered after combustion. The bottom ash adhered to the boiler wall falls down boiler bottom by its weight. Its particle size is about 1-2.5mm and has the distribution of about 15-20% of total ash production. The bottom ash gathered on boiler’s lower part is ground by the clinker grinder, transported to the ash pond by means of ash slurry pumps or pneumatically conveyed to fly ash silo for reuse. The economizer and air preheater ash has their particle size of about 0.3-1.0mm, covers about 5% of total ash production.
　　The ESP fly ash collected in ESP has generally the major particle size of 10-30m and the distribution of approx 75-80% of total ash production ,depending on the coals or combustion conditions, the fly ash is pneumatically transported to fly ash silo by means of transport blower or compressor, In recent ,the fly ash is utilized for cement additive or construction materials after the ash classification process to lower the unburned content of this fly ash.
　　Bottom Ash Handling System
　　Slag and ash falling from the furnace are temporarily stored in the bottom ash silo, They are then sent to the ash pond using a hydro ejector, Alternatively, they are sent back to the bottom ash silo to be recycled after going through a submerged drag chain conveyor or dry ash extraction conveyor.
　　. Bottom Ash Hopper System utilizing Hydro-ejectors
　　.SDCC(submerged Drag Chain Conveyor)System.
　　.Dry Ash Extraction System.
　　Pyrites/Mill Reject System
　　The pyrites produced from Pulverize are discharged to the ash pond by means of hydro ejector or conveyed to bottom ash silo by a screw feeder and belt conveyer.
　　.Hydraulic System utilizing hydro-ejectors
　　.Mechanical System utilizing conveyors
　　Economizer& Air Preheater Ash Handling System
　　The economizer and air preheater ash collected in 4-6 hoppers are discharged to ash pond through hydro-ejector and ash transfer tank or transferred to fly ash silo by pneumatic conveying system.
　　.Hydraulic System utilizing hydro-ejectors,
　　.Pneumatic Conveying System.
　　ESP Fly Ash Handling System
　　For the Fly Ash Handling for power plants, pneumatic conveyor system have world-widely been applied(ESP, Bag Filter, Etc) .The fly ash handling system transports the ashes pneumatically with the compressed air from blower or air compressor through proper pipeline to the ash silo.
　　.Positive pressurized Conveying System
　　--lean(dilute) phase System
　　--Medium Phase System
　　--Dense Phase System
　　.Negative Pressurized Conveying System (Vaccum System)
　　.Combination System
　　.Mechanical System
　　Ash Disposal System
　　.Ash Slurry Pump System
　　.HCSD (High Concentration Slurry Disposal) System