METHOD OF REMOVING UNBURNED CARBON FROM FLY ASH

• Main Authors: SAITO SHINICHIRO, ABE KAZUO, KIMOTO KOSUKE, MURATA TOSHIAKI
• Format: Patent
• Language: English
• Published: 18.01.2007
• Subjects: DIFFERENTIAL SEDIMENTATION; DISPOSAL OF SOLID WASTE; FLOTATION; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLIDMATERIALS OR FLUIDS; PERFORMING OPERATIONS; RECLAMATION OF CONTAMINED SOIL SOIL; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS; SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATICTABLES OR JIGS; TRANSPORTING

PROBLEM TO BE SOLVED: To efficiently remove unburned carbon from fly ash and to attain effective utilization of the fly ash and removed unburned carbon. SOLUTION: Water is added to the fly ash to obtain a slurry. A collector is added to the slurry and shearing force is applied to the slurry and the collector to attain surface modification. Then the mixture is subjected to flotation operation at which the unburned carbon of the fly ash is attached to froth and is surfaced. Application of the shearing force to the slurry and the collector can be carried out by means of a submerged agitator whereby agitation power of 0.7 to 10kWh/m3per unit quantity of slurry is applied. Fly ash concentration of the slurry is in a range of 3 to 50 wt.% and amount of the added collector is in a range of 5 to 100 wt.% based on the amount of the unburned carbon of the fly ash. The unburned carbon separated by flotation can be used as fuel and the fly ash (a product) having its unburned carbon content reduced to 1 wt.% or below can be used as a cement mixing material or a raw material for production of lightweight aggregate. COPYRIGHT: (C)2007,JPO&INPIT