System field Test Report
General CommentsThere is measurable improvement in yields of finer gold with the 151S over the 151. Our test site has most gold in the -20 to +300 range and the increase in yield is significant. Assay reports will quantify that at a later date.
Modification of the 151 to 151S was relatively easy. A few adjustments were made in the procedure to complete the modifications.
In terms of gold recovery, we did not do full assay testing on yields compared to lost values in tailings. The material we processed was not dry due to significant rainfall and snow this year. Our season for operating dry this year was reduced to a few weeks of dry weather.
Most of the gold was recovered by the 151S in the -20/+50 range. There was also gold recovered in the -50 to less than -100 mesh range. This was a significant difference from gold recovered by the 151 (unmodified), indicating a higher overall recovery rate for fine gold.
Parallel processing of the same material yielded approximately 35% more gold using a wet process, over the 151S. Not surprising, with damp material.
The 151S Dry Washer performs best in dry, well differentiated material. Clay and shattered bedrock does not process well as gold adheres to the clay and is not captured by the 151S. Preprocessing of clay and shattered bedrock material should increase yields. Testing will be done on this next season.
We plan to run more tests after our test material has been dried and pre-processed with a sieve, i.e. #12, at our lab. Our shaker was not on site to run this test.
151S – Setup at test site #1
Material at this site was dry for about the first 4 – 6 inches at the time of our test and then damp the rest of the way down to bed rock. We’ve sampled this area of the claim many times and know the yields for dry material. We did run a sample through our wet process for comparison.
151S – Working the wet stuff, comparing machines.
The 151S found good gold while a second machine from another manufacturer only produced one speck of gold at this test location. Both runs were ¼ yd of material out of the same strata.
The other machine was the same basic design as the 151S, with these major differences:
1. No air preheat
2. No electrostatic sandwich
3. No hopper shaker
4. No flow spreader (Scrubbing Pins)
5. Less air coming up out of the box at same 3000 RPM setting, using the same Honda 160 blower motor as the keene rig.
151S – Preheat does make a difference with damp material
151S – Good flow spreading even with damp material
Not a lot of dry ground here