Abstract: A mixing system for a power washer includes an electrically actuated valve communicated with a supply of a working fluid, and having a valve head that is movable between open and closed positions to control the flow rate of the working fluid through an outlet of the valve. The outlet of the valve is communicated with a fluid passage of the power washer to enable flow of the working fluid into a primary fluid and discharge of a mixture of the primary fluid and working fluid from the power washer when the valve is open, and to provide a flow of primary fluid from the power washer when the valve is closed.

Abstract: A method for recovering gold from gold-loaded fine carbon residue from a coarse carbon gold recovery process is disclosed. The gold-loaded fine carbon residue is mixed with activated coarse carbon and an aqueous solution of a transfer reagent to form a slurry. In the slurry the reagent promotes transfer of gold from the fine carbon to the coarse carbon. After allowing time for the transfer, gold-loaded coarse carbon is separated from the slurry. Gold can then be recovered from the separated coarse carbon, for example by cyanide leaching followed by electrowinning. More gold can be recovered by adding further coarse carbon and repeating the transfer of gold to that coarse carbon. In one example 66% of gold was transferred from the fine carbon to the coarse carbon in one transfer cycle. About 89% and 96% of gold can be recovered after respectively second and third transfer cycles.