Metal extraction index 1. Introduction to Metal Extraction 2. Extraction of Iron and Steel Making 3. Extraction of Aluminium and Sodium 4. Extraction of Lead, Zinc, Titanium and Chromium 6. Copper rich ores are relatively rare, so very valuable, so production costs are quite high.
Copper ores are concentrated by a technique known as froth flotation. The ores are roasted to drive off unwanted water and convert them to a more suitable chemical form for reduction to copper metal.
After reduction of the ore the liquid copper can be run off from the coke fired copper smelter furnace. Below are descriptions of the extraction of copper with balanced chemical equations.
The balanced equations quoted below, are a simplification of what can be quite complicated chemistry, BUT they do adequately describe and illustrate the chemical processes for extracting copper from its ores. The ore can be roasted to concentrate the copper as its oxide. Water is driven off and the carbonate thermally decomposed. The carbon acts as the reducing agent — the 'oxygen remover', gains oxygen and gets oxidised. REDOX definition reminders — reduction is a process of oxygen loss or electron gain and oxidation is a process of oxygen gain or electron loss.
From copper sulfide ores This can be roasted in air to produce copper I sulfide which is roasted again in a controlled amount of air so as not to form a copper oxide see below. Nasty sulphur dioxide gas is formed, this must be collected to avoid pollution and can be used to make sulphuric acid to help the economy of the process.
Oxidation-reduction theory for this displacement reaction: The copper obtained from the smelting processes described above is too impure to use, so it is purified by electrolysis details further down the page. Phytomining Phytoextraction 'mining with plants', Extracting copper in this way is a commercial example of phytoextraction.
Less energy is needed - smaller carbon footprint. Raw materials for the electrolysis process : Impure copper from a copper smelter. Electrolysis calculations 4d. Copper is a good conductor of electricity and heat, can be bent but is hard enough to be used to make pipes or tanks and does not react with water. It is a much more hard wearing metal than copper too soft and zinc too brittle but is more malleable than bronze for 'stamping' or 'cutting' it into shape.
Copper is used in electrical wiring because it is a good conductor of electricity but for safety it is insulated by using poorly electrical conductors like PVC plastic. Copper is used in domestic hot water pipes because it is relatively unreactive to water and therefore doesn't corrode easily. Copper is used for cooking pans because it is relatively unreactive to water and therefore doesn't corrode easily, readily beaten or pressed into shape but strong enough, it is high melting and a good conductor of heat.
Copper is also used as a roof covering and weathers to a green colour as a surface coating of a basic carbonate is formed on corrosion. Iron and steel are used for boilers because of their good heat conduction properties and high melting point. Copper compounds are used in fungicides and pesticides e. Copper is alloyed with nickel to give 'cupro—nickel', an attractive hard wearing 'silvery' metal for coins.
The extraction of copper from copper ores. How is copper extracted? Purification of Copper by Electrolysis extraction from ore above. The impure copper from a smelter is cast into a block to form the positive anode. Concept diagram for the purification of copper by electrolysis of copper salts solution with copper electrodes. Doc Brown's School Science Website.
All copyrights reserved on revision notes, images, quizzes, worksheets etc. Copying of website material is NOT permitted. All that happens is that there is a transfer of copper from the anode to the cathode. The cathode gets bigger as more and more pure copper is deposited; the anode gradually disappears. Any metal in the impure anode which is below copper in the electrochemical series reactivity series doesn't go into solution as ions.
It stays as a metal and falls to the bottom of the cell as an "anode sludge" together with any unreactive material left over from the ore. The anode sludge will contain valuable metals such as silver and gold. Metals above copper in the electrochemical series like zinc will form ions at the anode and go into solution. However, they won't get discharged at the cathode provided their concentration doesn't get too high.
The concentration of ions like zinc will increase with time, and the concentration of the copper II ions in the solution will fall. For every zinc ion going into solution there will obviously be one fewer copper ion formed. See the next note if you aren't sure about this. Note: If it isn't obvious to you that for every zinc ion going into solution there will be one fewer copper ion, think of it like this.
For each copper ion that is deposited as metallic copper at the cathode, two electrons need to flow around the circuit. Where are they coming from? Esentially, it is the anode's job to supply them. They are released there when copper or zinc atoms lose electrons and go into solution as ions. The power source then pumps them around the external circuit to the cathode. So, to deposit one copper ion at the cathode needs two electrons.
On the other hand, while copper sulfide ores are less abundant, they contain higher amounts of copper. Although the processing costs are higher, ultimately more copper can be extracted. Since each mine site is unique in its mineral composition, concentration, and quantities, the most economical and profitable processing of ore must be determined by the mine planners.
When it is economically feasible, a mine may extract both types of copper minerals; when it is not possible, mines will only process either the copper oxides or the copper sulfides.
The first steps of copper processing are the same for both ores: mining and transporting. Copper mining is usually performed using open-pit mining , in which a series of stepped benches are dug deeper and deeper into the earth over time. To remove the ore, boring machinery is used to drill holes into the hard rock, and explosives are inserted into the drill holes to blast and break the rock. The resulting boulders are then ready for hauling; specialized haul trucks, conveyors, trains, and shuttle cars can all be used to haul the ore from the blasting site to the processing site.
The size of the equipment needed to haul the tons and tons of ore is gigantic. Most ores are then sent through a primary crusher, which is typically located very close to or sometimes in the pit.
This primary crusher reduces the size of the ore from boulder to golf ball-sized rocks. Oxide ores are generally processed using hydrometallurgy. This process uses aqueous water-based solutions to extract and purify copper from copper oxide ores at ordinary temperatures, usually in three steps: heap leaching, solvent extraction, and electrowinning.
Heap Leaching is the process of using percolating chemical solutions to leach out metals. Sahu and Chmielowiec identified the cell voltages in their cell as 0. At the cell operating temperature and at an applied potential of 0.
Separate experiments also proved the ability to selectively reduce rhenium or molybdenum without reducing copper, based on their differing decomposition energies. Important strategic and commodity metals including, copper, zinc, lead, rhenium, and molybdenum are typically found in sulfide ores and less commonly in oxide-based ores, as is the case for aluminum.
A lot of engineering has gone into that for the aluminum industry, so we would hopefully piggyback off of that. Sahu and Chmielowiec conducted their experiments at 1, C, about degrees Celsius above the melting point of copper. It is the temperature commonly used in industry for copper extraction. To improve their cell efficiency, Sahu says, they may need to modify the cell design to recover a larger amount of liquid copper.
The electrolyte can also be further tuned, adding sulfides other than barium sulfide and lanthanum sulfide. That work continues. Chmielowiec, 27, a second-year doctoral student and a Salapatas Fellow in materials science and engineering, received his BS in chemical engineering at MIT in and an MS in chemical engineering from Caltech in The Allanore Group is seeking a patent on certain aspects of the extraction process.
The Allanore research group at MIT is at the forefront when it comes to advancing molten salt electrolysis research.
Direct electrolysis of the metal sulfide ores is also advantageous as it eliminates the formation of sulfur dioxide, an acid rain pollutant. The new approach can be applied to other metals of high strategic importance such as the rare earth metals. Previous item Next item. Massachusetts Institute of Technology.
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