Topic 8: Metals Flashcards
What is a metal? its characteristics
- element, compound, or alloy
- good conductors of heat and electricity
- malleable, ductile, shiny
- form cations through electron loss
What are native metals?
- metals occurring in the crust in its metallic “pure” form
- copper, silver, gold are the main elements that are found as native metals
What are available metals?
- any kind of metal found in the crust, usually found with other metallic elements, available thru mining and smelting
- found as abundant or scarce metals
what are alloys?
- chemical mixtures of 2 or more metals
- superior strength, durability, corrosion resistance
What are ores?
- metals found in crust with low concentrations
- mixed with other stuff
-can be concentrated under certain geological or geodynamic processes - to be considered an ore deposit, concentrations must be legally, technically, and economically extractable
what are some abundant metals?
- iron
- manganese
- aluminum
- titanium
- magnesium
What metals do we use the most? Why?
- iron
- very strong and durable, ease of smelting and processing
- very common to find, abundant and available and has a low cost
What do we use iron form?
- construction, transportation, machinery
What ores are economically extractable for the purpose of iron?
- oxides: hematite, magnetite, goethite
- sulphides: pyrite
where is iron found in contact metamorphic deposits?
- in skarn-like deposits
- iron-rich hydrothermal fluids excluded from cooling igneous intrusions, react with adjacent rocks
where is iron found in ignenous sources underwater?
- in seafloor volcanism, submarine hydrothermal activity
- black smokers! solutions of iron and silica
What are some sedimentary sources of iron?
- bog iron
- ironstones
- banded iron formations
What are banded iron formations?
-BIFS supply majority of our global iron production, contain 20-40% iron
- present in Precambrian rocks
- rocks that literally have bands of alternating iron oxide and silica
- iron sources come from weathering in the absence of oxygen
How can iron be mined?
- small scale, local extraction of iron stone
- commercial scale, open pit mining of iron deposits close to surface
What is benefication?
the enrichment of an ore prior to smelting
What are the different kind of steels made with iron?
- carbon steels (iron+carbon)
- alloy steels (iron+other elements like silicon, nickel..)
- stainless steels (iron+ chromium)
What is manganese used for?
- added to iron smelting to scavenge sulphur and oxygen
- using in water treatment, and dry cell batteries
Manganese is precipitated as ore minerals such as…
- pyrolusite
- psilomelane
- romanechite
- rhofochrosite
What is the second most abundant metallic element in the crust?
Aluminum
the main ore for aluminum is..
bauxite, which contains gibbsite and boehmite and diaspore
how is bauxite formed?
- by advanced chemical weathering of aluminum rich rocks, in wet tropical conditions
Where is aluminium NOT found on earth? why?
- arctic areas
- due to cold and glacial erosion
titanium is the ___ common abundant metal
LEAST
What are the main ores of titanium
ilmenite and rutile