Gravity Concentration

Wilfley Table

wilfley table

The Wilfley table is a truly remarkable gold concentrating table first built on a preliminary scale in May, 1895. The first full-sized table was built by Mr. A. R. Wilfley, and was used in his own mill in Kokomo Colo., in May, 1896. The first table sold for installation was placed in the Puzzle mill, Breckenridge, … Read more

Heavy Liquid Testing Procedure

Dense Heavy Media Separation Test

The general procedure is as follows. The sample is placed in the liquid of lowest specific gravity and is split into two fractions. The float fraction is set aside to be weighed and assayed. The sinks fraction is washed in a suitable solvent, dried and placed in the liquid of a higher specific gravity. This … Read more

Bowl Concentrators

Bowl concentrators have been used only to a limited extent in small placer operations. The two most popular designs were the Ainlay and Knudsen bowls. There is little difference in design and operation between the two, except for riffle design and minor variations in bowl size and shape. They were used primarily as cleaners, but … Read more

Falcon Enhanced Gravity Separator

Enhanced gravity separation devices (centrifuges) have been patented for over a century but were impractical until recently. The physical laws behind the concept were well understood but engineering had to catch up with the science. This included the development of abrasion resistant materials, the improved design of rotating equipment that allowed higher RPM, and a … Read more

Mercury Amalgamation

Mercury or quicksilver fed into stamp mortar-boxes and riffles or applied to copper plates has been for ages the method of catching free gold. Many millions of ounces of gold have been saved thereby, and the mercury has been returned to circulation with small loss. Amalgamation is still practiced, but the recovery of gold by … Read more

Cheap Sluice Mat – Corduroy

Details of the use of corduroy are given in the section covering gold and silver, but there is no reason why this material should not be used by the small miner in the concentration of any sulphide ore—silver, mercury, copper, lead, antimony, and sphalerite, for example. Corduroy forms part of the concentrating equipment of the … Read more

Gold Planning

I have been given the opportunity to maybe teach you guys how to pan some gold and find some gold. I’ve been prospecting, my family been prospecting for many years. So we have a good mine just up the road. And hopefully today we can go out and find a little bit of Gold and … Read more

Gravity Concentrators & Jigs Compared

A Gravity Concentrator has the bed fluidized 100% of the time. A Jig is fluidized only 50% of the time. A Gravity Concentrator works at 150 g forces. A Jig works at 1 g. Material is caused to move in a lateral movement through the Gravity Concentrator. A Jig has a lateral movement and a … Read more

Flour Gold Recovery

Flour gold can be defined as ultra-fine gold found in a low micron size fraction, often smaller than 74 microns or 200 mesh.  Reality is that with today’s fine gold recovery equipment, this is a low ways away from the elusive microscopic gold small prospectors want to know how to recover.   Falcon’s iCon gravity … Read more

Diamond Dredge

With regards to diamond dredges and dredging, the kings of the 1970s were Consolidated Diamond Mines and Marine Diamond Corp. both parts of the famous DeBeers company, control the coast of the Namib Desert and the waters and more important, the ocean floor and beaches of this treasure cheat of gems. So rich were the original … Read more