Explanation on the Jig and Sluice Box

There are a lot of questions as to the validity of the problems that we encountered at the mine. Yes, the shaker was a real piece of work! The incompetence of the engineers who decided to modify that shaker speaks for itself. The engineering of the entire washplant was a lack of planning from the beginning. It is very important when setting up any wash plant to make sure that where the ore that you are classifying and separating has enough drop to allow for the slurry to move through the plant without clogging up at any point yet also moving at the correct velocity to separate the gold. This is achieved by a simple plan which includes setting up constant variables that are outlined in the most basic of mining engineering books.

The wash plant was held up at several points because there was not one plan drawn up before they set the machines in place. The sluice box was not wide enough to allow for the rate of material that was being dropped into it from the beginning. We spent days adding water hoses to blast the material and even had a man standing there to power wash the material through the sluice box. My opinion was to just leave out the expanded metal section (which is what made it a sluice in the first place) since we had a 42? duplex pan american jig at the end of the line anyway. If that Jig was setup correctly there should be no reason to use a sluice before the jig. Removing the miners moss and the number 3 expanded metal (that wasn’t working due to water starvation) was an easy solution at the time.

The jig had the same problem as you can see above in the clip as Thurber was cleaning the clogged sand out of the diaphragm for the tenth time. After spending a couple days finding small flakes in the jig tailings I called the jig manufacturer and spoke with the inventor (AAA Manufacturing). He explained in five minutes three major mistakes we were making when setting up the jig. Number one, we didn’t have enough volume going to the hutch water which is what the diaphragm pumps up and down to separate the higher specific gravity ore (gold and magnetite) from the gangue material. Number two, we needed a check valve so when the diaphragm pumped down it would not change the pressure in the hutch. And three, the pressure hose was not large enough to create the right head pressure. Also, there was not a constant cross flow that was measurable as far as slurry ratio but that is one variable that is really hard to keep consistent. You at least need the other variables somewhat dialed to catch the majority of the gold.

The jig concentrates flowed down into two 3/8? openings which are really just a pee stream into a open pipe…YES an open pipe which can BE CUT (1/2 pipe) to create a channel. Boneheads!  I needed a 1/12 pitch to clear that drain pipe which we were at 1 inch for every 2 feet when I decided to cut that pipe to fit.  I would have either jacked up the jig or dug out underneath of it if anyone would have given me a hand.  Undermining a 4000 lb jig is not a smart idea.  Especially when you paid only half of $7000.00 for it (not 30K like the program says) and it is full of 1/4 inch steel shot that can spill out if it were to tip over.  They are worth more than the jig itself!

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