Question. Suppose that you are building a new house. It will take about 90 kg (198 pounds) of copper to do the electrical wiring. In order to get the copper in the first place, someone needs to mine solid rock that contains copper, extract the copper minerals, throw away the waste rock, and smelt the copper minerals to produce copper metal.
A typical ore contains only 0.5% to 2.0% copper. It is a measure of the value of copper that it is worth extracting it from such small concentrations. The ore is a mixture of minerals and rock (called gangue ).
Copper mines are only set up where there is more than 5 kg of copper per tonne of rock (0.5% by mass). Ideally, the figure should be closer to 2%. The worlds largest copper ore deposits are found in Chile on the west coast of South America. This is due to the volcanic activity that is part of the process that created the Andes mountain chain.
The percentage of copper in the actual ore is too low for direct extraction of copper to be viable. The concentration of ore is required and it is done by the Froth Flotation method. Concentration of Ore The ore is crushed into a fine powder and a suspension is created in water. To this are added, Collectors and Froth Stabilizers.
In some cases, tailings have been retreated to recover lost value as the technology for recovering copper has improved. The average grade of copper ores in the 21st century is below 0.6% copper, with a proportion of economic ore minerals (including copper) being less than 2
The amount of copper in an ore can vary from 0.4 percent to more than 12 percent. Porphyry copper deposits , in which the copper materials are more or less uniformly scattered throughout the rock, account for the greatest tonnage of metal in the producing areas of the world.
Copper deposit grades are usually expressed as a weight percentage of the total rock. For example, 1,000 kilograms of copper ore containing 300 kilograms of copper metal has a grade of 30 percent.
Copper Applications in Mining Extraction. Copper ore, in concentrations ranging from 0.29 percent to ten times that amount, is mined from open pit or underground mines The crushed mine ore is ground in rod and ball mills and then sent to flotation machines where the copper mineral rises to
Extracting copper from other ores. Copper can be extracted from non sulphide ores by a different process involving three separate stages Reaction of the ore (over quite a long time and on a huge scale) with a dilute acid such as dilute sulphuric acid to produce a very dilute copper(II) sulphate solution.
Jan 19, 2006For the entire globe, the researchers estimate that 26 percent of extractable copper in the Earth's crust is now lost in non recycled wastes. For zinc, that number is 19 percent.