Process for reforming the fly ash

• Main Authors: Omura, Kohei, Seki, Takuya
• Format: Patent
• Language: English
• Published: 31.05.2024
• Subjects: AIR; ARTIFICIAL STONE; BLASTING; CEMENTS; CERAMICS; CHEMISTRY; COMBUSTION APPARATUS; COMBUSTION PROCESSES; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; DISPOSAL OF SOLID WASTE; HEATING; LIGHTING; LIME, MAGNESIA; MECHANICAL ENGINEERING; METALLURGY; METHODSOR APPARATUS FOR COMBUSTION USING FLUID FUELOR SOLID FUEL SUSPENDED IN; OTHER SEPARATING BY DRY METHODS APPLICABLE TO BULK MATERIAL,e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL; PERFORMING OPERATIONS; RECLAMATION OF CONTAMINED SOIL SOIL; REFRACTORIES; SEPARATING SOLIDS FROM SOLIDS; SEPERATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, ORSIFTING OR BY USING GAS CURRENTS; SLAG; SORTING; TRANSPORTING; TREATMENT OF NATURAL STONE; WEAPONS

The invention is a fly ash modification method, whereby a fly ash raw powder containing unburnt carbon is heated to reduce the unburnt carbon content, characterized by: (a) using a heating device as a means for heating the fly ash raw powder, wherein heating is performed by passing the fly ash raw powder through a heated medium fluidized bed; (b) passing a high temperature gas flow through the inside of the heating device, thereby forming the heated medium fluidized bed and performing fluid transport of the fly ash raw powder introduced into the medium fluidized bed; (c) setting the flow rate of the high temperature gas flow in such a manner that the entire amount of the fly ash raw powder introduced into the heating device is heated by the medium fluidized bed and collected from a collection port provided in an upper portion of the heating device, while the medium particles forming the medium fluidized bed are not discharged from the collection port; (d) introducing, into an air classifier, the heated fly ash powder discharged from the collection port of the heating device so as to separate the fly ash powder into a fine powder and a coarse powder; (e) recovering as modified fly ash the fine powder recovered by the air classifier; and (f) measuring the unburnt carbon content in the coarse powder recovered by the air classifier, re-introducing the coarse powder into the heating device and re-heating if the measured value is greater than a preset threshold value, and recovering the coarse powder as modified fly ash if the measured value is smaller than the threshold value.