a freind of mine did some great DD and found this......
Norman Pearson currently is the acting president of Thunder Gulch Resources Ltd. which just signed a 48-month contract with DKGR. He holds a patent on a gold recovery machine for placer or free gold mining, "The Pearson Rock Box" and he helped develop the "The Derocker."
(Friends, I think the following excerpts may help our collective level of confidence in this gentleman and in Clayton's wisedom in have him on the team...)
Patent verification, background, and validation of Pearson's role.
Title: Sluice box
United States Patent 4360424
Inventors: Pearson, Norman A.; Crawford, Gary W.;
Application Number: 255779
Filing Date: 1981-04-20
Publication Date: 1982-11-23
Assignee: Pearson; Norman Anthony
Current Classes: 209/44, 209/380, 209/458, 209/498, 209/500
International Classes: B03B 007/00
Primary Examiner: Lacey; David L.
Attorney, Agent or Firm: Carver & Co.
BACKGROUND OF THE INVENTION
This invention relates to a sluice box apparatus for recovering heavy material, such as gold, from an aggregate.
Placer gold deposits are found in areas where veins and lodes of gold have been exposed and eroded due to such forces as glaciers, water and rock slides. Such deposits are found, for example, in certain areas of the Yukon Territory and the province of British Columbia, Canada.
Several different techniques have been developed over many years for separating placer gold from the surrounding aggregate. Prospectors traditionally use a gold pan in creek beds.
A larger scale placer mining operation requires an apparatus such as a sluice box. This consists of a trough placed on an incline and having riffles on the bottom thereof. The riffles are blocks or laterally extending bars for catching the gold. The riffles are commonly placed on top of matting, such as coco mat or indoor/outdoor carpets, which traps the finer gold particles. In use, a stream of water flows along the sluice and gold bearing aggregate is added to the sluice. The gold particles are trapped by the riffles and matting, while the remaining aggregate and water is discharged at the end of the sluice.
Because the price of gold has increased dramatically in recent years, it has become increasingly important to improve the recovery of gold from such placer mining devices. The devices used in early years were relatively inefficient and a considerable amount of gold, particularly fine material and gold flour, was discharged from the sluice boxes or other devices. For example, in the Ross device found in Canadian Pat. No. 1,074,263, a superfine recovery section has been added to the lower portion of the fine recovery channels to attempt to recover fine material not recovered by the upper portion of the device. However, the need for an inherently more efficient placer mining device remained.
SUMMARY OF THE INVENTION
According to the invention, a sluice box apparatus for recovering heavy materials, such as gold, comprises a fine recovery channel and a coarse recovery channel. The recovery channels have a receiving end, riffles and matting for collecting fines of the material.
By double washing the aggregate with the water discharged from the water distributing means and with the water circulating upwardly through the perforations in the perforated plate, a considerably more efficient sluice box apparatus results. The upwardly circulating water occurs because of the restricted flow of water through the fine discharge opening. A higher portion of fine materials are washed from the aggregate and pass through the perforations to the fine recovery channel instead of being discharged into the coarse recovery channel. The fine recovery channel may be specifically adapted for the recovery of gold from such fines. The means for restricting the flow of water to the fine recovery channel allows the flow to be adjusted for optimal recovery of fines.
The present invention offers significant advantages when compared with earlier sluice box apparatuses.
For example, by having discharge openings between the hopper and the fine recovery channels which have a size that can be restricted, water can circulate upwardly through the coarse material again adjacent the discharge end of the hopper and wash additional fines which pass through the perforated plate and then to the fine recovery channels. Additional fines can be trapped by the riffles near the receiving end of the coarse recovery channel because of the second perforated plate 120 over this end of the coarse recovery channel.
I have located a 10-page PDF with actual diagrams but am unsure how to convey without breaking rules here....
AI
