Placer Gold Recovery Methods By Michael Silva Special Publication 87

Placer Gold Recovery Methods By Michael Silva, Special Publication

1986
California Department of Conservation
Division of Mines and Geology
1416 Ninth Street
Sacramento, California 95814

Contents

Introduction.......................................................................................................Pg. 1
Concentration of Placer Gold Ore.....................................................................Pg. 2
Small Scale Recovery Equipment.....................................................................Pg. 2
   Gold Pan.........................................................................................................Pg. 2
   Rocker............................................................................................................Pg. 3
         Construction.............................................................................................Pg. 3
         Assembly..................................................................................................Pg. 5
         Operation..................................................................................................Pg. 5
   Sluices............................................................................................................Pg. 6
         Long Tom.................................................................................................Pg. 7
         Dip-Box....................................................................................................Pg. 8
   Shaking Tables...............................................................................................Pg. 8
   Portable Processing Equipment......................................................................Pg. 9
   Amalgamation................................................................................................Pg. 10
Dry Placers........................................................................................................Pg. 10
   Dry Washers...................................................................................................Pg. 10
   Air Tables (Oliver Gravity Separator) ..........................................................Pg. 11
Modern Recovery Equipment...........................................................................Pg. 12
   Pinched Sluice Systems (Reichert Cone) ......................................................Pg. 12
   Spiral Concentrators ......................................................................................Pg. 13
         Rotating Spirals........................................................................................Pg. 15
         Helixes.....................................................................................................Pg. 15
   Jigs.................................................................................................................Pg. 16
   Fine Material Separators................................................................................Pg. 20
         Bartles-Mozley Separator........................................................................Pg. 20
         Bartles CrossBelt Separator.....................................................................Pg. 21
   Centrifugal Concentrators..............................................................................Pg. 21
         Bowls.......................................................................................................Pg. 21
         Knelson Concentrator..............................................................................Pg. 22
Summary...........................................................................................................Pg. 22
Operating Mines...............................................................................................Pg. 23
   Hammonton Dredge......................................................................................Pg. 23
   Hansen Brothers - Hugh Fisher.....................................................................Pg. 25
         Bear River...............................................................................................Pg. 26
         Greenhorn Creek.....................................................................................Pg. 26
   TRI-R Engineering - Stinson Mine...............................................................Pg. 27
Selected Annotated References........................................................................Pg. 29
Appendix: List of Equipment Manufacturers and Suppliers...........................Pg. 31