How to Get Gold Out of Rocks

Most gold comes from hard rock mines.

Mining gold is a labor- and cost-intensive process usually done in several stages: the removal of the gold from the mine, the sorting and crushing of the rock and gold and the extracting and purifying of the gold that results. Although machines and technology have made it easier in some parts of the world to mine for gold ore, the removal of it from rocks and concentration process remains relatively the same. Large companies have the funds for this process; otherwise, mining and processing gold can be extremely hazardous to humans.

Things You'll Need

• Gold ore in rocks
• Mercury
• Sodium cyanide solution
• Shaker screen
• Crusher machine with conveyor belt and grizzly
• Ball mill
• Holding tanks
• Clarifier
• Deaerator tank
• Water

Instructions

1. Remove the gold ore (gold found within rocks) from the mining site. Large deposits are rare, and gold is usually found in small amounts in its elemental state among the rocks.

2. Sort the gold ore according to size with the grizzly and conveyor belt. Wash the ore during this stage of sorting to allow the shaker machine to remove any bits of rock and ore less than 1/2 inch diameter into a fine ore bin or box beneath. The larger bits will be crushed in the crusher before joining the fine ore pieces.

3. Place the fine ore on the conveyor belt to a ball mill, a rotating steel cylinder full of tumbling steel balls, to further pulverize the ore and separate gold from rock. The result is a substance the consistency of sand or powder.

4. Choose the method for extracting the gold: amalgamation or vat leaching. Amalgamation requires mercury; use it on the ore to dissolve the gold, and then boil it off and distill the gold. This method is very expensive. Vat leaching is more common. Put the ball mill powder in a thickener with a sodium cyanide and water mixture to create a sludge.

5. Direct the sludge into holding tanks. Remove the sludge from the holding tanks using clarifier to remove the remaining rock substances from the ore.(ref. 1) Further clarify the solution by sending it through a deaerator tank.

Tips & Warnings

• Do not attempt to mine gold on your own. Experience is required. Permits are required. Crews and volatile substances are required.

• Removing gold from rock requires products such as cyanide and mercury, which are deadly to humans and other living creatures.

• Removing gold from rocks by individuals is not recommended.

• Further purification processes are required on the remaining gold solution to create actual gold. At the point of deaeration, there should be no clay or rock left in the solution.

References

• Mining the Motherlode; Hard Rock Mining - The Process; June 2000
• Bullion Vault: Gold Mining