How to Interpret Assay Values
January 2018 by Don Robinson
This assay system of ounces per ton sounds simple enough, but the use of the metric system and the additional measuring terms of “grams per ton” and “parts per million” (ppm) has created some misunderstanding of ore value.
This explains the large difference in particle sizes between placers and hydrothermal lode deposits, but also means that while the mining may be similar in some cases, the sampling and recovery techniques are usually quite different.
Choosing the right method to move your ore and waste is all about making the right choices. Sometimes more than one method may be used during the life of a mine as an operation expands and grows.
The first step in my recovery process after milling the ore to the desired size is to table it. On this particular ore, I get good results milling it to minus 100 mesh.
At one time or another, many miners will look seriously at purchasing a mining claim...Usually it’s a significant financial commitment, so how do you know if you are getting a good deal?
I regularly get inquiries along the line of: “Hey, I found this rock, and I think it might be gold ore. How can I tell?” Prospectors are always on the lookout for gold-bearing rocks that may be the source of any nearby placer gold.
Because quartz and gold may be deposited together across a considerable range of temperatures, not all quartz veins are the same, and there are several different types of gold-quartz deposits.
After he excavates the ore down to bedrock, he goes over the bedrock with a metal detector to ensure he didn't leave any gold behind before he backfills the area.
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