fed directly into a steel mill as a feed source the combustion products in the form of exhaust dusts vapors and fumes are recovered by a filter process such as a bag house or a wet scrubber the zinc lead cadmium and copper in the waster material are vaporized in the heating and reduction step 200 and comprise a majority of the exhaust dusts vapors and fumes the heating and reduction step 200 is not necessary if there is no significant iron content in the waste the heating and reduction step 200 is a fourth example of how waste from the present process in this case iron oxides is usable further reducing the amount of waste produced by the present process once the waste material is reduced the process as represented in fig2 continues just as the preferred embodiment represented in fig1 the combustion product the exhaust dusts vapors and fumes are leached in leaching step 100 undissolved materials 102 are separated from the leachant and the leachant first product solution is subjected to cementation step 104 to remove pb cd and cu for further processing 108 the remaining solution second product solution is diluted with water in a dilution step 106 to 2 10 nh 4 cl thus prompting zno to precipitate out of the solution the now remaining solution third product solution is then concentrated back to gt 30 nh 4 cl in a concentration step 110 and is recycled back into the process as a leaching solution waste materials typically have varying.