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CaO ( s ) + SiO 2 ( s ) CaSiO 3 ( l )

Just below the middle of the furnace, the temperature is high enough to melt both the iron and the slag. They collect in layers at the bottom of the furnace; the less dense slag floats on the iron and protects it from oxidation. Several times a day, the slag and molten iron are withdrawn from the furnace. The iron is transferred to casting machines or to a steelmaking plant ( [link] ).

This figure shows a photo of molten iron. A bright yellow-orange glow appears just left of center in the figure. Smoke appears to be rising toward the top center of the figure. Just below and to the right, sparks appear to be falling.
Molten iron is shown being cast as steel. (credit: Clint Budd)

Much of the iron produced is refined and converted into steel. Steel is made from iron by removing impurities and adding substances such as manganese, chromium, nickel, tungsten, molybdenum, and vanadium to produce alloys with properties that make the material suitable for specific uses. Most steels also contain small but definite percentages of carbon (0.04%–2.5%). However, a large part of the carbon contained in iron must be removed in the manufacture of steel; otherwise, the excess carbon would make the iron brittle.

Isolation of copper

The most important ores of copper contain copper sulfides (such as covellite, CuS), although copper oxides (such as tenorite, CuO) and copper hydroxycarbonates [such as malachite, Cu 2 (OH) 2 CO 3 ] are sometimes found. In the production of copper metal, the concentrated sulfide ore is roasted to remove part of the sulfur as sulfur dioxide. The remaining mixture, which consists of Cu 2 S, FeS, FeO, and SiO 2 , is mixed with limestone, which serves as a flux (a material that aids in the removal of impurities), and heated. Molten slag forms as the iron and silica are removed by Lewis acid-base reactions:

CaCO 3 ( s ) + SiO 2 ( s ) CaSiO 3 ( l ) + CO 2 ( g )
FeO ( s ) + SiO 2 ( s ) FeSiO 3 ( l )

In these reactions, the silicon dioxide behaves as a Lewis acid, which accepts a pair of electrons from the Lewis base (the oxide ion).

Reduction of the Cu 2 S that remains after smelting is accomplished by blowing air through the molten material. The air converts part of the Cu 2 S into Cu 2 O. As soon as copper(I) oxide is formed, it is reduced by the remaining copper(I) sulfide to metallic copper:

2Cu 2 S ( l ) + 3O 2 ( g ) 2Cu 2 O ( l ) + 2SO 2 ( g )
2Cu 2 O ( l ) + Cu 2 S ( l ) 6Cu ( l ) + SO 2 ( g )

The copper obtained in this way is called blister copper because of its characteristic appearance, which is due to the air blisters it contains ( [link] ). This impure copper is cast into large plates, which are used as anodes in the electrolytic refining of the metal (which is described in the chapter on electrochemistry).

This figure shows a large, dull, black, lumpy mass with small, metallic flecks displayed on a clear, colorless rectangular solid base.
Blister copper is obtained during the conversion of copper-containing ore into pure copper. (credit: “Tortie tude”/Wikimedia Commons)

Isolation of silver

Silver sometimes occurs in large nuggets ( [link] ) but more frequently in veins and related deposits. At one time, panning was an effective method of isolating both silver and gold nuggets. Due to their low reactivity, these metals, and a few others, occur in deposits as nuggets. The discovery of platinum was due to Spanish explorers in Central America mistaking platinum nuggets for silver. When the metal is not in the form of nuggets, it often useful to employ a process called hydrometallurgy    to separate silver from its ores. Hydrology involves the separation of a metal from a mixture by first converting it into soluble ions and then extracting and reducing them to precipitate the pure metal. In the presence of air, alkali metal cyanides readily form the soluble dicyanoargentate(I) ion, [ Ag ( CN ) 2 ] , from silver metal or silver-containing compounds such as Ag 2 S and AgCl. Representative equations are:

Questions & Answers

how do u derive this fundamental constants
Bertram Reply
am not sure how
Shehu
do you have an idea
Shehu
no
Mugala
that's why am asking
Bertram
what is an atom
Idah Reply
An atom is the smallest indivisible particle of an element that is capable of independent existence
akinboboye
That's conventional thinking since the Greeks and our current teaching, but it's been discovered that atoms are made up of even smaller subatomic particles called "quarks". Until fully understood let's stick with the current knowledge that an atom is the smallest unit of mass being indivisible
Jallal
What is rightful definition of element
angela Reply
an element is the group of (vertical columns) of the periodic table exhibit similar chemical behaviour.
Barnabas
okay
angela
is alkanes a saturated hydrocarbon?
Faith Reply
yup
Oladayo
it's saturated cos it has single bonds
Oladayo
yh....because they don't undergo additional reactions which hydrogen and other atoms can add across the carbon-carbon or triple bond
patience
and me...I'm I wrong?
patience
how does metal looses electron
Sammy Reply
By oxidation and reduction
hamidat
by oxidation loss
Official
An acid is a proton donor.
Eric Reply
what is an acid
Amara Reply
an acid is a substance when dissolved in water produces hydrogen ion or hydroxonium ion
hamidat
good
Mudassir
thanks
hamidat
is a substance which dissolves in water to produce hydrogen ions as the only positively charged ions
Kwagala
what is ionic bonding
Kylian Reply
It involves the transferring of electron from a metal to a non mental
hamidat
that's right
Edward
bonding between a metal and a non metal
miriam
calculate the hydrogen ion concentration of the solution when pH=5
Adamu Reply
answer pls
Adamu
What is thermodynamics
prince Reply
what is the meaning this word twentieth
dhu
Is the branch of physics that deal with heat and temperature and their relation to work, energy and properties of matter
Edward
There are no topics on hydrocarbons
Zina Reply
they are there please check under organic chemistry in the contents.
Kwagala
its not making sense to me I still don't understand
megan Reply
How and why
Betrice
yes
megan
we need diagram for easy going and understand
serah
How can we easily differentiate between the 5 gas laws
Favour Reply
first amd foremist me i only know 3 gas laws, so please list them here
Kwagala
the gas laws i know include pressure law boyles law charles law i differentiate these with this formular big take classy pork pigs. viral i read thus as 1 big classy pigs take pork viral big.....take means in boyles law,temp is constant clasy.....prk mns in chrls lw, press cons
Kwagala
classy.....pork means in charles law pressure is constant pigs.....viral means, in pressure law volume is kept constsng ,the rest is the same boyles states that vol of a gas is inversely prop to volume keeping temp constant charles law, state vol of a gas is directly prop to temp keepn pressure cns
Kwagala
how many carbon is present in alkene
Alase Reply
it's the carbon to carbon being double bonded to each other that makes it an alkene, not the amount of carbon itself. ex: C=C, C=C=C. both are alkenes.
Phill
I need more light on alkene
chidera
an alkene is a hydrocarbon, you can find this under the sub topic of organic chemistry in this textbook, check it out please,but before you know about alkenes you should first know about alkanes, alkanes are saturated and dnt easily react while alkenes have double bonds and can react .
Kwagala
other usefullness of hydrogen apart from this, it is colourless, odourless and tasteless
Bukunmi Reply
it is neutral to litmus paper, it is insoluble in water
hamidat

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Source:  OpenStax, Chemistry. OpenStax CNX. May 20, 2015 Download for free at http://legacy.cnx.org/content/col11760/1.9
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