We have two types of Gold Mining, one is hard rock mining and the other is alluvial gold mining. Hard rock mining implores the method of blasting the rock with danamite, crushing the rock into smaller sizes and smelting them and using a concentrator to separate the smelted gold materials from the impurities, usually more complex operation than Alluvial gold mining. The word alluvial simply means washing by employing the method of separating the gold bearing materials (AU) from the sand.
As the names implies, hard rock miming deals on gold deposits inside rocks and Alluvial mining deals with gold deposits inside the depth of surface of the mine, which consist of gold bearing materials mixed with sand,small stones and clay. The depth where these (AU) Gold bearing materials are deposited ranges from two meters to six meters depth or more.
However, I will be focusing on Alluvial gold mining since is my area of specialization and narrowing it down to West Africa as I have first hand experiences in this region. Do look for subsequent Articles as I will be blogging series of Articles on this subject,watch out for more and enjoy reading as knowlegde is power.