PROBLEM TO BE SOLVED: To provide a method for producing sintered compacts by using exhaust powder from a cast process as a raw material which enables highly general-purpose materials to be produced at a low cost as an effective method for utilizing slag and dust discharged from a cast process. SOLUTION: This method is to employ slag and dust discharged from a cast process as raw materials, to crush and sift the slag to form slag powder adjusted to have a specific particle diameter, to calcine the dust at 300-800 deg.C and then to crush and sift the calcined dust to form dust powder adjusted to have a specific particle diameter, to blend the slag powder with the dust powder in such a way that the content of the slag powder is 40-70 wt.%, to mold the blended powder and to burn the molded product at 850-1,050 deg.C. The blended powder consists of coarse grained powder having a particle diameter of 100-500μm and fine grained powder having a particle diameter of 0.5-5μm and an average particle diameter of 2μm.
