Method for extracting heavy metals from hard rock and alluvial ore

摘要

A machine is employed for recovering heavy metals and precious or semi precious minerals, such as gold, copper, lead, diamonds, and garnets from placer, or hard rock ore. The machine employs a cylindrical, annular outer drum mounted for rotation at an inclination to the horizontal and including at least one spiral vane extending the length of its inner surface. A cylindrical, annular inner barrel is mounted within the drum and has an upper fragmentation section, an intermediate screened section, and a lower discharge section. A spray of water is directed into the inner barrel and a water spray bar is located in the annulus between the inner barrel and the outer drum. A fine sluice box is located to receive under one-quarter material input from a side trommel and a coarse sluice box located to receive discharge from the side trommel and discharge from the fine sluice box. The sluice box includes a plurality of landings, matting and screens upon which heavy materials, such as gold or precious stones, collect.

主权项

1. A process for separating heavy metals from ore using an outer hollow cylindrical drum inclined relative to horizontal to define upper and lower ends and having at least one spiral vane extending inwardly from said outer drum's inner wall and radially extending lip at said lower end, an inner cylindrical barrel located within said outer drum and inclined relative to said outer drum, and at least one sluice box having upper and lower ends operatively coupled to said outer drum, comprising the steps of:
rotating said outer drum at a first speed in a direction such that said spiral vane urges material therein toward said upper end of said outer drum and toward said upper end of said at least one sluice box, wherein the spiral vane is divided into a first section, second section, and third section, wherein the third section comprises a single height and the first section comprises generally a double height, and wherein a pitch of the third section is less than a pitch of the first and second sections rotating said inner barrel at a second speed greater than said first speed, directing discharge from said upper end of said outer drum as an input into said sluice box, and directing a spray of water into a trommel section of said inner barrel.