CHAFF CHARCOAL, PRODUCTION OF THE SAME, AND FERTILIZER AND SOIL IMPROVING AGENT CONTAINING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain a chaff charcoal which is loaded with a water soluble phosphoric acid salt on surface or in small holes thereof by heating and carbonizing the chaff absorbing a moisture in a state of little oxygen supply, adding a water soluble phosphoric acid salt powder and agitating, and to obtain an excellent soil improving agent by using the obtained chaff charcoal. SOLUTION: This modified chaff charcoal containing approximately 3-20wt.% phosphoric acid salt, is obtained by charging dried chaffs into a chaff carbonizing device equipped with an agitating function, spraying approximately 5wt.% silica sol solution based on the chaffs, while agitating, then adding a prescribed amount of Mg3 (PO4 )2 and K3 PO4 powders under the agitation, firing the chaff carbonizing device, heating at 150-600 deg.C in a state of little oxygen supply to carbonize the chaffs. Also, by heating the chaffs at 150-600 deg.C for the carbonization, and spraying an aqueous solution of the water soluble phosphoric acid salt before the chaff charcoal is cooled, the modified chaff charcoal is obtained.