Development of Grizzly Gold Trap Sluices

The Grizzly Gold Trap features numerous design improvements over previous fluid bed sluices including:

• Angled transport deck section

• Higher capacity gold capture chamber: fewer cleanouts

• Improved transport of material over grizzlies: fewer jam-ups

• More efficient fluid bed/capture chamber: captures and holds gold

• Increased capture and retention of fine gold: capture with confidence

• Sampling riffles: Assesses gold in material

Engineered to Improve Fluid Dynamics and Fine Gold Retention

Design concepts for the Grizzly Gold Trap originated from performance analysis of earlier models of fluid bed sluices, like the Bazooka sluice, and determining what design features could be improved, as well as determining which features performed well. Working with an engineering expert — more than 40-years experience in fluid dynamics — we developed various computer models of the Grizzly Gold Trap, which went through numerous changes designed to improve ease of set-up, retention of gold (especially fine gold smaller than -100), and running of unclassified material.

Simulated Stream Test System

Based on our fluid bed design models, prototypes of the Grizzly Gold Trap were fabricated, including a transparent model tested in our recirculating water system. The recirculating system was developed specifically to study how material typically associated with gold (various sizes of gravel, light sands, black sands, etc.) moved and stratified on the transport deck, passed through and over the grizzly, entered the fluid bed chamber, stratified within the chamber, and was either held in the chamber or was exchanged out. Through these tests and observations, we gained a more in-depth understanding of how gold (from +20 sizes to -200 sizes) and other heavies stratify within different sections of the sluice, what design features help fine gold settle out of the laminar flow regimes, and how our fluid bed design (turbulent flow regime) continued to stratify and exchange material. In addition, we discovered design concepts that helps capture and retain a higher percentage of fine gold as small as -200. Based on the results of our testing and redesigns, the Grizzly Gold Trap was ready for field testing.

Field Testing

Field testing of the Grizzly Gold Trap was conducted in numerous environments, including small streams to rivers with low to high flow rate conditions. In addition, we tested the Gold Trap in areas that ranged from mostly fine gold (-50 to -200 and smaller) to areas have fine to courser gold (-100 to +20 and larger).

Grizzly Gold Trap

The culmination of our design approach is the new generation of fluid bed sluices — the Grizzly Gold Trap.

Commitment to Quality

Our research and design improvement efforts will continue. We understand that there are always ways to improve our line of products and will continue to strive to improve our designs and to design and develop accessories like a high banker for the Explorer and MotherLode models, and a support-leg system.