| 摘要 |
<p>A method that continuously carries out drying safely and efficiently without explosion such as steam explosion and the like, or adhesion of the metal sludge into a retort by allowing the metal sludge to be dried by a rotary kiln in reusing of metal sludge is provided. A method for continuously treating metal sludge comprises: drying a metal sludge to a moisture content of 30% or less; loading the dried metal sludge into a rotary kiln; and heat-treating the dried metal sludge at a high temperature in the rotary kiln until a moisture content of the metal sludge becomes 10% or less. The metal sludge is a sludge containing rare earth magnetic alloys. The metal sludge has a moisture content of 20% or less after drying and has a moisture content of 5% or less after heat treatment at high temperature. The method further comprises finally drying the heat-treated metal sludge at a temperature of 100 to 200 deg.C for 10 minutes to 5 hours after heat treatment at high temperature. The drying is performed by heating the metal sludge in a drying furnace at a temperature of 50 to 500 deg.C and an atmospheric pressure or a reduced pressure for 10 minutes to 5 hours. The heat treatment is performed by directly heating the metal sludge in a rotary kiln at a temperature of 400 to 1000 deg.C and an atmospheric pressure or a reduced pressure for 10 minutes to 3 hours.</p> |
