MANUFACTURE OF COMPOSITE SNOW-MELTING AGENT

摘要

PURPOSE:To obtain a composite snow-melting agent having a fertilizer effect in addition to a snow-melting effect, by covering the surface of a powdery compost derived from sewage sludge and a granulated material prepared therefrom with a finely divided black carbonized compost. CONSTITUTION:A powdery compost obtained by completely aging an organic sludge discharged in a large quantity by the action of an aerobic microorganism in the process for purifying sewage sludge in the terminal treating facilities is used. In the manufacture of a composite snow-melting agent, a compost is sifted to give a powder having a particle diameter of about 3.4mm or less, and the water content is adjusted to about 20-25%. A granulated compost which has been made to have a particle diameter of 1.0mm or less and a water content of about 20-25% is used. The powdery compost is subjected to low- temperature carbonization at about 300-600 deg.C and is then ground so that at least 80wt% particles pass through a 200-mesh sieve. About 5-20pts.wt. finely divided black carbonized compost is added to about 100pts.wt. powdery compost and granulated compost that have each a particle size and water content thus adjusted, which are mixed by stirring to cover the surface of the latter composts with the former compost, thus giving an objective snow-melting agent.