So I was actually reading a random wikpedia article this afternoon about gold mining just for fun and this popped up -
Saying your conventinal sluice box loses about 60%, now maybe some of the old timers sluices were that bad, but honestly I would say most of the time our boxes probably recover somewhere from 90-99% of the gold depending on the area and the amount of heavys, and even in the hardest to work area we have ever found (all micro micro gold dust and insane amount of different types of heavy’s) I still find we are catching at a bare minimum at least 75% even when not classifying and being careful.
But I was wondering what is everyones standard sluice recovery rate, and at what point do you start slowing the flow down and trade efficency for recovery? Whenever we find we are losing anymore then a 1/5th of the gold we will generally slow the sluice down/decrease the angle or start classifying more, what is everyone elses preference on this?
Interesting question! I would be surprised of many people systematically check their tailings regularly enough to be able to answer. Which is unfortunate really as testing your tailings is helpful imao. I’ve thankfully never seen much in any tailings testing I have done. But do test reasonably regularly when I remember to.
You’d have to think you’d have something wrong to only catch 40% in the sluice as the article says but maybe I’m wrong. I can imagine using a dredge losing a decent amount if its set up weirdly. I’ve seen a set up with someone not using a damper, where they likely lose a bunch of gold when it was running the pump pretty high, for obvious reasons. That damper is kinda important piece on a dredge to force the water down on the riffles! But does it count if you have something not right? I’d like to think even that would catch more than 40%?
I think would be happy with anything higher than 90%. But def not happy if I lost any big bits. Normally you have a decent feel dredging what you are seeing. So I dont think I am losing more than that. Great question!
ive got 2 mats in my dredges a front and back as well as dampner, if my front mat is not catching 95% of the gold im not happy, normally only dust on my back mats , infact i dont like seeing pickers anymore than about a 5th the way down my box, im never running anymore than 1/2 to 3/4 revs on my motors, i use black V mat to make sure im on the gold and thats right at the start of my box , alot of the gold dosnt even get past that, i will wash up the front mat twice a day especially in heavy black sand areas
Yup @webby1 same here. Never want to see gold lower in the box! I also keep the revs pretty low, like you - unless there is some new kitty litter washed into my hole I want to just smash out, theres just no need to rev high - and it saves petrol and my fingers I wish I had a nuggy for every time I thought there was a rock over the nozzle only to reach down and find there wasn’t - and ouch!
I guess the people with hot water transfers may need the engine rev’d higher? not sure, I’ve never run a hot water transfer from fear of cooking myself.
im hearing you im running a 5 inch proline and it will bust fingers quick as look at you, learnt real quick to keep fingers away from nozzle , nothing beats my body up like gold dredging , ill take a hiding then be back for seconds soon as im healed lol
Yesterday I was trying to sluice at the bottom of a rapid. The speed of water entering the flare was way too fast, even though the volume was not huge and pitch of box was low. Managed to slow entry speed down to where you could see gold move last out of flare, which gives the riffles a chance to do their thing. Prefer slow as possible while maintaining a good exchange, fine line though sometimes I just cant quite hit that perfect sweet spot.
I wish I had a nuggy for every time I thought there was a rock over the nozzle only to reach down and find there wasn’t - and ouch!