How Santo mines the gold
Once exploration has indicated gold in economic quantities, extracting gold is a relatively straightforward task. Here is how we do it:
Open Pit Gold Extraction
Extraction requires a mine, of which there are several varieties. For purposes of extraction, Santo Mining will use quarry-style open pit or underground mines. For more intensive mining activity, Santo will partner with an experienced junior mining company or sell the claim outright to a large operation.
Simply explained, there are three steps to open pit mining: Accessing the ore-bearing pay dirt, loading it onto trucks, and transporting it to a processing facility. Depending on the constitution of the ore-bearing dirt, extraction techniques could be a simple as mechanical digging, or as complex as explosive blasting to loosen the materials first. The material is then loaded onto trucks for transportation to the processing facility.
The soils must be processed to extract the ore, and specific processes differ based on the quality of the ore. Most ores are milled into a fine powder. This powder is put though a processes to sift metallic minerals from the waste material. Once sifted, gold is extracted by a chemical or thermal process. For oxide ore, cyanide dissolves out the gold from the rest of the materials. When the ore contains carbon, it is heated to more than 1,000 degrees F, which burns off both the carbon and the sulfide. After this, the ore can be treated with cyanide in special tanks to leach out the gold. In some cases, the ore must be autoclaved to responsibly separate out sulfide, before beginning the leaching process.
Lower grades of ore go directly to the leaching process. It is essentially heaped into a pile, where the gold is leached out with a cyanide solution.
Then activated carbon is introduced to gold bearing cyanide solution. Gold accretes on the carbon and is then removed for smelting into bars. These bars are not pure, but are themselves shipped to offsite refineries to processing to 99.99% purity, or bullion.
Mine site remediation
Santo Mining work is not finished when the gold is successfully removed from the ground. To satisfy our corporate values and the regulatory environment, our process includes restoring the areas affected by our mining process to as good or better condition that it was before our involvement. Ideally, we are able to return the same soil to the area from which it was extracted.