Designing an incinerator for recovery of the yellow and white metals is a little bit complicated.  The combustion chamber will be under negative pressure because of the ID fan, but this will result in the fine dust running away with the flue gas, making recovery difficult. It should, therefore, be either a slightly positive pressure or addition of downstream equipment to capture the flying dust, preferably a bag house. In that case, the flue gas from the secondary chamber has to be cooled down to around 200°C before entering the baghouse.

Secondly, the waste containing the precious metals are generally loaded in trays and charged. The trays cannot be provided with holes for air/heat to enter the trays because that will result in falling of the metal dust into crevices and corners, making it a cumbersome process for recovery. The chamber should be designed in such a way that the heat is concentrated below the trays, like cooking in a pot, so that the tray conducts the heat effectively to the waste and burns out the organic contents.

There can be two types of heating, one with the help of burners and the other with a hot air generator. Both are effective, but the design with the burners is less expensive but as effective as the one with the hot air generator.

There are refineries and manufacturers who tell us that they are able to recover the cost of the incinerator in less than 6 months and so the ROI for our PMR model  incinerator / precious metal recovery furnace is extremely good.