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From time-to-time we will publish mining & prospecting tips here.


You can use a semi-trash pump, a trash pump, a centrifugal pump, or a high pressure pump with a Hydro-Force Nozzle. Semi-trash pumps are a good choice because they will pass small pebbles and sand. A trash pump will safely pump rocks up to the stated size, say 2". A high pressure pump is one that has an extra high head. They are more expensive. We recommend semi-trash pumps or your basic centrifugal pump. You should put the foot valve in a bucket to keep debris out of it. You can also wrap a foot valve in panty hose to keep stuff out. The main thing is to have enough gallonage to have a reserve to allow you to pump up grades or heights above the pump output port. We would not recommend using a pump less than 72 gpm. You don't want a pump that pumps the minimum required as those stats apply to sea level pressure and a straight, horizontal pumping action. 

The nozzles are designed to be used with clear flow pressure hose. We do not recommend the use of layflat hose or the use of fire hose. Both are prone to kinks which decrease pressure and performance. Fire hose is woven and the little ridges create friction which reduces suction and performance. Fire hose and layflat hose are both cheaper but you will have problems in performance. 

To clear a jam in the nozzle, use a 6" or 8" screw driver to dislodge a rock. If necessary, turn off the water and remove the suction hose from the nozzle port. Use the screw driver to knock loose a rock jammed in the nozzle. 

Do not strike the nozzle on a rock in an attempt to unjam a nozzle. Doing this can damage the valve and stop the suction. Now you've got a broken nozzle.

Try to use no more pressure hose than needed for the distance you expect to work. Having "excess" hose or a longer hose than needed lowers performance and suction.  Rather than one long hose, use two shorter hoses and connect them as needed for longer distance. When you pump up hill you lose powe. When pumping uphill and a long distance from your pump (over 25'), we suggest you step up to the next size in engine and pump. The gallonage figures we give are minimums for nozzles. For example, use a 5hp engine instead of a 4 hp. Or go to a 6 1/2 hp or a 9 hp engine. If you plan to pump 10' or more out of a hole you might use an inline jet tube and second engine helper unit. These examples and tips are based on experience and conversations with principals at Keene Engineering and Proline Dredge. 

A rule of thumb is that the bigger the nozzle the fewer jams. The 3" nozzle is a good blend of size and weight for most users. Be cautious about using the smaller sizes as the have much less capacity and will jam more often.  One way to reduce jams is to spot weld a 1/8 "diameter piece of steel rod across the gravel intake. A weld shop can do this in a few minutes at little cost. 

Remember placer mining is about volume and low grades.


Learning to do your own fire assays is an important skill for those with a serious interest in prospecting and mining. Once you learn you'll wonder how you ever got along without it. The tools and ability to do a field fire assay is as important as learning to pan and owning a sluice. We can help you get started. Just inquire.

Two important things to remember about placer mining. 1. Placering has long been about low grade ores and volume. There is a fad today about getting every last little color. But the key is volume. This means the larger nozzle sizes are your best bet. You want to move more gravel if you want more gold. 2. The second key to more gold is team work. Getting more gold is about working together in groups or teams, about owning a claim together, sharing in costs and rewards. 

Here are some tips on what to look for in quartz rock that might hold gold. As a rule, dirty quartz is better. Grey is good and so are reds, browns and black stuff on the quartz. You want to see iron compounds, like iron oxides. Pyrites are good to have too, especially arsenopyrite, and graphite, a black mineral. The redder the better! Snow white quartz is more likely to be barren, but there are exceptions. Sugar quartz may be high grade ore. It looks like a grainy, sugary milky color, in contrast to hard, white, glassy quartz. A vein showing both types of quartz may be high grade ore. I found a sugar quartz lode that assayed 3 oz./ton AU and there was no visible gold showing. 

How to calculate the mass of a fire assay gold bead and the $ per ton. Use a 40x comparator with gradations in .001"  to measure the diameter of the tiny bead. We sell these for you. For example, you get .010." Now, the formula for mass is D cubed x 10.4326. The later number is Hunich's constant. He was a 19th century German scientist. D must be in millimeters, one millimeter in inches is .0254. If you have 10 units (as in .010") then multiply by 10. This is 10 x .0254 = .254. This gives .016387. Now .016387 x 10.43526 = .170959mgs. = .171 Mgs. Mgs = milligrams. Milligrams converts directly to ounces troy per ton. Therefore, .171 mgs = .171 ozs./ton troy, which at $1700.00/oz. = $290.70/ton AU. And now you know the REST of the story! This formual I obtained from a 19th centure book on fire assaying published in 1888!

The Spirit of 1872 - When the law becomes a tyrant, the good man becomes an outlaw. - Dave Howard