Classifying and air-stratifying gold separator with inclined sequential chute cone array and size-classifying screen

A gold separator adapted to achieve size classification of gangue and separation of heavy ore from the classified gangue comprising

• an inclined sequential chute in a mixer box section for receiving a slurry of mineral matter and water,
• a size-classifying screen with a mesh onto which the slurry is received in the chute,
• an array of cones downwater of the mesh screen and disposed such that the slurry continues over and past the array and down the chute, the cones each comprising an opening directed downwater over which the slurry rapidly passes and adapted to develop a low-pressure region at the cone opening as a consequence of the slurry passing rapidly over and past the cone opening,
• a perforated collecting mat with a textured collecting surface below the screen for collecting material passing through the screen and settling out of the water,
• a plurality of nozzles under the perforated collecting mat for jetting fluid from below into the perforated collecting mat such that settled material on the mat is lifted from the mat surface,
• at least one strip under the plurality of nozzles transverse in the chute disposed to retain fine ore as water flows over the at least one strip, and
• means for connecting the nozzles to a source of fluid.

A method of separating gold ore from gangue in placer mining employing a mixture of water, ore and gangue, comprising the steps of

• depositing the mixture in a chute;
• classifying the mixture by size within the chute to exclude gangue larger than ore;
• separating ore from the remaining gangue within the chute;
• destroying any size classification within the mixture and depositing the mixture less separated ore into a subsequent chute adapted to reclassify the mixture by size prior to separating ore from the remaining gangue, the reclassifying step comprising separating and removing gangue in said subsequent chute from ore mixed in gangue of size smaller than was separated and removed in the preceding chute;
• jetting fluid into the collecting mat such that material is lifted from the mat for further ore separation, and
• providing a size-classifying screen within each chute at each chute entry end onto which the slurry is received wherein each screen in a successive chute has a smaller mesh than preceding screens.