Is extracting metals from ores cost effective?

Answer 1

Minerals are solid elements or compounds found naturally in the Earth's crust. Those minerals

that contain sufficient metal to be of practical and economic use are called ores. Metals are

usually extracted from ores using a combination of heating and reduction with carbon in the form

of charcoal or coke. Not all metals can be extracted from their ores in this manner and may need

to be extracted by a process called electrolysis.

Metals with low chemical activity, such a gold and silver are normally found in their pure state.

Copper, tin, lead, and iron are more reactive and must be heated with carbon to extract the metals.

Aluminum, calcium, sodium and other active metals are extracted using electrolysis.

Copper can be extracted from its ores by reduction. One of the common copper ores, malachite,

which is composed of mainly copper carbonate, CuCO3xCu(OH)2, is heated to produce copper

oxide with the release of carbon dioxide.

CuCO3xCu(OH)2 → 2 CuO + CO2 + H2O

The copper oxide is then heated with carbon to get copper.

2 CuO + C → 2 Cu + CO2

The resulting copper, however, is pure enough to be used for many industrial applications, but it

has to be further refined for electrical uses. That copper is cast into thick sheets known as anodes

and are placed in large electrolytic cells filled with a copper sulfate solution. A DC electric

current is passed through the cells causing the copper anodes to dissolve and deposits pure copper

on the opposite pole called the cathode. The final product is between 99.94 and 99.96% Cu.