"I do think they need to really think about upgrading their wash plant, that trommel is ancient and their sluice could be a LOT wider with several horizontal banks of riffles. There is most likely a lot of fine gold in that ore. I would hate to think they are missing any "
Howdy Foxwoods. While I may agree the trommel could use a coat of paint if appearance improved gold recovery, but that is not the case. This plant, obtained 25 years ago, utilizes a specialized sluice system to avoid the large, space hungry, parallel and or series sluices folks see on TV. Remember the Ruby millsite is on the side of a mountain and working space is at a premium. Brush Creek trucked this specialized wash plant from Canada (and got it stuck under a bridge during that trip ;) and was infamous for going all out (much to the dismay of their investors) when it came to their facilities. My guess is primary sluice is nearly 4 feet wide and about 20 feet long. Thats not small. But thats not big like some large trommel operations. What is unique is this primary sluice has a walking bottom.. the riffles slowly counter rotate to the flow and dumps the concentrates down to a much smaller, final recovery sluice. The large sluice is continuously cleaning itself taking the heavy flow and load from the trommel meaning the riffles are not silting up from fines or loading up from heavies, which is the primary reason you need long multiple sluice systems. Once a sluice loads up its cleanout time and that means downtime for production, a lot of downtime if we are talking 4 boxes @ 40 foot long. The small sluice at about 20" x 10' long wide is a low flow designed to catch the fines with unique riffles and modern miners moss to retain them once caught. Its easy and quick to cleanout and is very accessible alongside the catwalk. It produces much less concentrates to cleanup. From the runs made so far, gold has only been found in the upper few riffles.
The wash plant also utilizes a sand screw and conveyor system to manage the tailings. Our site is small and settling ponds are limited in size so we cant just dump all the tailings into the pond. They would backfill too fast. The larger rock is classified off and stock piled. The sand screw dewaters the smaller material from the sluice outfall and is also stockpiled by conveyor. The loader off-hauls the waste to a near by disposal site. Only dirty water and silt is dumped into the settling ponds and that reduces downtime required for pond maintenance.
This is a highly thought out wash plant $$$ and what worked 25 years still works today. Can we make it better? Sure. You can classified out the fines and run that through multiple jigs and onto tables or a whole myriad of other expensive recovery systems. However this area is well known for course gold not fine gold. Why spend a dollar to save a nickel? From my observations the company is running a tight ship and running this operation smart. I like that.
