Metals And There Uses Flashcards
How do why retrieve ores and what do we do with them once they are collected?
Ores are mined and may be concentrated before the metal is extracted and purified.
How are unreactive metals found and how are most metals found?
Unreactive metals such as gold are found in the Earth as the metal itself, but most metals are found as compounds that require chemical reactions to extract the metal.
How can metals less reactive to carbon be extracted from the oxides?
By reduction with carbon
E.g. Iron oxide is reduced in the flats furniture to make iron
How can metals more reactive to carbon be extracted from the oxides?
Metals that are more reactive than carbon, such as aluminium, are extracted by electrolysis of molten compounds. The use of large amounts of energy in the extraction of these metals makes them expensive.
How can copper be extracted from copper-rich ores?
By heating the ores in a furnace (smelting). The copper can be purified by electrolysis. The supply of copper-rich ores is limited.
New ways of extracting copper from low-grade ores are being researched to limit the environmental impact of traditional mining. What are these two new ways of extracting copper?
Phytomining-this uses plants to absorb metal compounds and that the plants are burned to produce ash that contains the metal compound
Bioleaching-this uses bacteria to produce leachate solutions that contain metal compounds
How can copper be obtained from solutions of copper salts?
By electrolysis or by displacement using scarp iron
What two metals can not be extracted from the oxides by reduction with carbon?
Aluminium and titanium
Why are current methods of extracting aluminium and titanium expensive?
There are many stages in the processes
Large amounts if energy are needed
Why should we recycle metals?
Because extracting them uses limited resources and is expensive in terms of energy and effects on the environment
What does iron from the blast furnace contain?
Around 96% of it is iron
The impurities make it brittle and so it has limited uses
What is most iron converted into?
Steel
What is steel?
Steels are alloys since they are mixtures of iron with carbon. Some steels contain other metals. Alloys can be designed to have specific uses. Low-carbon steels are easily shaped, high-carbon steels are hard, and stainless steels are resistant to corrosion
Why are most metals we use nowadays alloys?
Pure copper, gold, iron and aluminium are too soft for many uses and so are mixed with small amounts of similar metals to make them harder for everyday use.
What are the elements from the central block on the periodic table known as?
Transition metals.
Like other metals they are good conductors of heat and electricity and can be bent or hammers into shape.
What are transition metals useful for?
Useful as structural materials and for making things that must allow heat or electricity to pass through them easily.
What do the properties of copper make it useful for and why?
Electrical wiring and plumbing.
It is a good conductor of electricity and heat
It can be bent but is hard enough to be used to make pipes or tanks
It does not react with water
Why is aluminium and titanium useful?
Because they are low density and resistant to corrosion
What do ores contain?
Enough metal to make it economical to extract the metals the economics of extraction may change over time.
Why is copper extracted from ores containing a low percentage of copper compounds?
Very little left of high gradence
High demand
Economic value
Give one reason why it is difficult to dispose of waste rock
Waste rock takes up a lot of space
Why is extracting pure copper expensive?
Large amounts of ore to be mined
Many extraction stage
