Extracting Unreactive Metals

Extracting Unreactive Metals

What Are Unreactive Metals?

  • Unreactive metals are metals that do not easily participate in chemical reactions.
  • Gold, platinum and silver are examples of unreactive metals.

How Are They Extracted?

  • Because unreactive metals are often found in a pure state in the Earth’s crust, they do not require chemical reactions to be extracted.
  • This is a contrast to reactive metals which need to be extracted through processes such as electrolysis.

Extraction of Gold

  • Gold is often mined directly from the Earth’s crust. Miners dig deep into the earth to reach gold ore deposits.
  • The rock is then crushed and the gold separated from the other minerals typically by gravitation techniques.
  • One common method used in gold extraction is the cyanide process. In this process, gold is combined with cyanide to form a soluble compound allowing easy separation.

Extraction of Platinum

  • Similar to gold, platinum is often extracted by mining it directly from the Earth’s crust.
  • Platinum ores are crushed and milled to a fine grain, making the platinum easier to extract.
  • Air is then passed over the ore mixture, and the platinum binds with sulphur-based compounds to form a layer of froth, which can be skimmed off for further processing.

Extraction of Silver

  • Silver is usually found within ores that contain a mixture of metals.
  • The silver is extracted through a process of crushing the ore and then heating it known as smelting.
  • The heating process drives off other elements and leaves behind the silver.

Environmental Impact of Extraction

  • Mining for unreactive metals can be damaging to the environment, causing habitat destruction and soil erosion.
  • The cyanide process used in gold extraction is particularly harmful as cyanide is a potent and dangerous chemical.
  • Various methods, such as recycling of already mined metals and improving mining practises, are being integrated to lessen these environmental effects.