The Dream Nugget: Gold Classification & Recovery
Understanding why gold classification is important
Classification is an essential part of good recovery technique, but understanding why to classify is equally important. Most miners classify to reduce large rocks from building up in their sluice. Classifying also allows you to reduce the water flow and pitch of your sluice bed. Smaller / lighter material requires less “force” to push it down and out.
Reduce water flow and pitch by classifying
Most miners will have riffles in their sluice. Larger rocks can easily stop in front of, behind, or between these riffles. When this happens, the ARMP (active reduction and minimization process) action of the sluice is effectively reduced to zero. Vortexes collapse, matting is covered, and no flow is occurring.
By classifying down to very small material, you can reduce the water flow and pitch, which creates a better “sluice environment” for catching gold, especially fine gold.
Integrating classification systems
Anyone who has mined will have noticed that large rocks have “material” stuck to them. Sometimes this material may contain gold, meaning you would benefit from an “integrated” classification system that will both classify material down and wash larger rocks prior to them being ejected.
Done properly, this one step can greatly increase recover rates. Remember, we DO NOT want these large rocks rolling down our sluice bed.
The Gold Lab uses this gold classification process to increase return, optimize, and assist the miner in knowing where most of his gold is coming from (ie -30, -50 or -100 particle sizes.) Just the simple act of taking this extra step will increase your chances for a higher yield recovery.
Capturing your “Dream Nugget”
Most of us dream about a big nugget turning up in our sluice. However, for the average miner this rarely, if ever occurs- especially those working areas for fine gold.
But screening, classifying or setting your grizzly / classification bars to a more realistic level will actually produce more gold recovery. You can reduce your water flow and pitch, and have a better chance of catching all sizes of gold, increasing your overall yield in total, if not in one dream nugget.
Again, classification is the key. Because gold is heavier than anything else in your concentrates – if the materials are segregated by size – gold, being 19 times heavier than water, will automatically win the displacement race if it is the same size as all other materials in your concentrates.