Your number one piece of equipment…. The one that will make you or break you… is the wash plant. Over the last 100 years, many new ideas and designs have come out… some good… some not so. They all do the basic concept of washing rock… but they also have many of the same faults.
Let’s look at these….
Nuggets in the wash plant – the hardest thing to capture. Virtually no wash plant is designed to capture a nugget larger than ½ ounce… not even the old dredges of the Yukon and California gold rushes. Those were designed to capture gold from ¾” to 3/8”. Most everything bigger than ¾” went out the trammel tailings.
The reason is a simple one, the size of the screen used in the trommels.
Even today, most plants run with ½” screens… no way for a large nugget to get through that… but that makes sense. In many cases, these are few and far between and then a larger screen would allow way too much material to get to the sluice. So, there it goes, out with the tailings for the next miner to find. There are ways of capturing those lost nuggets… metal detecting dischargers on the tailings conveyor… but of course, you must be in an area with larger nuggets.
Your screens should be sized as small as possible to allow the gold you have on your site to get through with a little extra. So, if your big gold is 12-mesh, an 8-mesh screen will do the trick.
Yes… smaller screens do mean slower feeds and less yards per hour… but it also means less water…. a very good thing when to goal is the capture smaller gold particles. It has been proven that two 20 YPH plants (reverse trommels) fed by one feeder will outperform a 50 YPH plant (screen) on the same ground… simply because of better water control.
Next blog… Sluices
“Gold is like women, some prefer lunch on the tailgate with a beer (nuggets) and some prefer wine and fine dining (fines)… think of your wash plant the same way… match for your capture goal.”