PRODUCTION OF ADSORBENT FROM REFUSE INCINERATION ASH

• Main Author: DANSEI YASUO
• Format: Patent
• Language: English
• Published: 18.04.2000
• Edition: 7
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; DISPOSAL OF SOLID WASTE; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; RECLAMATION OF CONTAMINED SOIL SOIL; SEPARATION; THEIR RELEVANT APPARATUS; TRANSPORTING

PROBLEM TO BE SOLVED: To carry out the removal, hydration, and partial mineralization of heavy metals to stabilize hazardous components with a relatively simple method, by putting refuse incineration ash under an alkaline condition, and by hydrothermally treating it. SOLUTION: Incineration ash is kept in a suspended state in an aqueous solution of an alkali such as sodium hydroxide and potassium hydroxide. Thereafter, it is hydrothermally treated for several hours or more at a temperature between 100 and 250 deg.C (optimally at about 180 deg.C) under saturation vapor pressure. Or, the incineration ash may be subjected to steam curing for several hours more at a temperature between 110 and 250 deg.C under saturation vapor pressure after being kneading with an aqueous solution of an alkali such as sodium hydroxide and potassium hydroxide to be molded. The reason why the temperature is set between 100 and 250 deg.C is that the temperature less than 100 deg.C makes the progress of the reaction difficult and the temperature above 250 deg.C not only makes the cost of a device high but causes the phase transformation of minerals to form a different crystal structure.