Abstract: A hand-held power tool comprises a drive unit including a first housing, a combustion motor located in and fixed to said first housing and having an output shaft; and a work unit including a rotatable tool, an input shaft, a transmission between the input shaft and the tool for driving the latter and a second housing. A quick-connection arrangement is provided for releasably connecting the first to the second housing and a coupling arrangement coaxial with the connection arrangement serves to couple the output shaft with the input shaft.

Abstract: In a Waelz process of volatilizing zinc and lead from iron-containing and oxide-containing material in an inclined rotary kiln, which is charged at its upper end with the material together with solid carbonaceous reducing agent having a high content of volatile combustible constituents, wherein the reduction and volatilization are effected below the softening point of the charge, metallic iron-containing material is discharged from the lower end of the rotary kiln, combustion air is sucked into the lower end of the rotary kiln, and the exhaust gases are sucked from the upper end, the improvement which comprises blowing oxygen-containing gases through tubular air nozzles into the charge disposed over said tubular air nozzles in that region of the heating-up zone which begins where ignitable particles of the solid reducing agent begin to occur and which terminates at up to 50 percent of the length of the kiln.