[Music] I'm welcome back to three sighs lessons cold UK by the end of this video you should be able to describe how vital mining and bio leaching are used to extract copper and this material is for higher-tier students only in earlier topic we looked at how to extract metals remember that most metals are found in the Earth's crust already reacted with other elements for example oxygen now the worldwide demand for metals is glowing and a really important metal is copper copper is used in electronic equipment such as phones I'm showing you a copper mine here every year millions of tons of metal ore are extracted from the Earth's crust in mines like this a metal ore contains enough metal to make it economical to extract the metal and the word economical means cost-effective now there is a problem here as copper ores are becoming scarce in other words they've running out this means that we're going to have to extract copper from low-grade ores low-grade ores contain only a very small amount of copper and that means that is harder to extract the copper economically from these ores so we're going to look now how this is done and you need to learn these methods the first method is called fight or mining in fight or mining plants are grown on land containing the metal compound that we want these plants absorb the metal compound and they concentrated in their tissue the plants are then harvested and burned at the end the ash contains a relatively high concentration of the metal compound now the other way of extracting metals is called bio leaching and this uses bacteria in bio leech and bacteria are mixed with the low grade or the bacteria carry out chemical reactions aren't they produce a solution called Elite Eight and the leachate contains a metal compound that we want so at the end of both phyto mining and bio Legion the metal compound that we want has been extracted from the low-grade ore we no need to extract the metal from the compound in the case of copper compounds we can displace the copper using iron that's because iron is more reactive than copper we usually use scrap iron which is cheap we can also extract the copper using electrolysis now there are a couple of key points about phyto mining and bio leaching firstly both of these allow us to economically extract metals from low-grade ores and that's important as the earth's resources of metal ores are limited secondly these methods do not involve digging transporting and disposing of large amounts of rock unlike in traditional miner remember you'll find plenty of questions on phyto mining and bio leaching in motivation work for and you can get that by clicking on the link above [Music]