resources - alternative methods of extracting metals

Question 1

where are most metals found?

Answer 1

in earth’s crust already reacted with other elements (oxygen)

Question 2

what is copper used in?

Answer 2

electronic equipment (phones)

Question 3

how is copper/metal ores extracted?

Answer 3

in mines

Question 4

what does a metal ore contain?

Answer 4

enough metal to make it economical to extract the metal

Question 5

Copper ores are becoming _____

Answer 5

scarce meaning we will have to extract copper for low-grade ores, these contain only a very small amount of copper so harder to extract economically

Question 6

how is copper/other metals extracted from low-grade ores by phytomining?

Answer 6

plants are grown on land containing the metal compound that we want. these plants absorb the metal compound and it is concentrated in their tissue. the plants are harvested and burned. at the end, ash contains relatively high concentration of the metal compound

Question 7

how is copper/other metals extracted from low-grade ores by bioleaching?

Answer 7

this uses bacteria. bacteria mixed with low grade ores. bacteria carry out chemical reactions + they produce a solution called a leachate. leachate contains metal compound we want

Question 8

what do we have at the end of phytomining and bioleaching?

Answer 8

the metal compound that we have extracted from the low grade ore but we now need to extract the metal from the compound.
- for copper compounds we displace the copper using iron as it is more reactive. use scrap iron as it is cheap. can also use electrolysis

Question 9

key facts about bioleaching and phytomining?

Answer 9

• economically extract metals from low-grade ores. important as earth’s resources of metals are limited
• don’t involve digging, transporting and disposing of large amounts of rock unlike traditional mining