# 19.1 Occurrence, preparation, and properties of transition metals  (Page 5/27)

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1. Preliminary treatment. In general, there is an initial treatment of the ores to make them suitable for the extraction of the metals. This usually involves crushing or grinding the ore, concentrating the metal-bearing components, and sometimes treating these substances chemically to convert them into compounds that are easier to reduce to the metal.
2. Smelting. The next step is the extraction of the metal in the molten state, a process called smelting, which includes reduction of the metallic compound to the metal. Impurities may be removed by the addition of a compound that forms a slag—a substance with a low melting point that can be readily separated from the molten metal.
3. Refining. The final step in the recovery of a metal is refining the metal. Low boiling metals such as zinc and mercury can be refined by distillation. When fused on an inclined table, low melting metals like tin flow away from higher-melting impurities. Electrolysis is another common method for refining metals.

## Isolation of iron

The early application of iron to the manufacture of tools and weapons was possible because of the wide distribution of iron ores and the ease with which iron compounds in the ores could be reduced by carbon. For a long time, charcoal was the form of carbon used in the reduction process. The production and use of iron became much more widespread about 1620, when coke was introduced as the reducing agent. Coke is a form of carbon formed by heating coal in the absence of air to remove impurities.

The first step in the metallurgy of iron is usually roasting the ore (heating the ore in air) to remove water, decomposing carbonates into oxides, and converting sulfides into oxides. The oxides are then reduced in a blast furnace that is 80–100 feet high and about 25 feet in diameter ( [link] ) in which the roasted ore, coke, and limestone (impure CaCO 3 ) are introduced continuously into the top. Molten iron and slag are withdrawn at the bottom. The entire stock in a furnace may weigh several hundred tons.

Near the bottom of a furnace are nozzles through which preheated air is blown into the furnace. As soon as the air enters, the coke in the region of the nozzles is oxidized to carbon dioxide with the liberation of a great deal of heat. The hot carbon dioxide passes upward through the overlying layer of white-hot coke, where it is reduced to carbon monoxide:

${\text{CO}}_{2}\left(g\right)+\text{C}\left(s\right)\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{2CO}\left(g\right)$

The carbon monoxide serves as the reducing agent in the upper regions of the furnace. The individual reactions are indicated in [link] .

The iron oxides are reduced in the upper region of the furnace. In the middle region, limestone (calcium carbonate) decomposes, and the resulting calcium oxide combines with silica and silicates in the ore to form slag. The slag is mostly calcium silicate and contains most of the commercially unimportant components of the ore:

#### Questions & Answers

what are the types of heat changes in chemical reaction
potassium is element number what, what is it symbol, what is it atomic weight, what it boiling point?
It is element number 19,symbol is K
Amha
atomic weight 39.0983g/mol boiling point 1047.0K
Johnson
I need 5 different and 5 similarities between compound and mixture
Mahmood
Mahmood
Mahmood
what is matter
Matter is anything that occupied space
Rasidi
matter is anything that has mass and occupies space
Johnson
matter is anything that has mass and volume.
rafaela
matter is any thing that can that has mass
samuel
a plot of the atomic radius against atomic number shows a periodic variation with group 1elements occupying the peaks and group 4 the troughs.plot the graph
what is the periodic table all about
yeah
samuel
it's about predicting the different types of matter around us and organizing them in an elegant way
William
what is boyle law
the law states that at a constant absolute temperature the volume of a fixed of a gas is inversely proportional to the pressure of the gas...
Johnson
write short not on paper chromAtogphy
I am sorry, I don't understand the question. Are you referring to photospectometry, a machine that uses lightwaves to determine the chemical composition of a substance? Instead of the "coffee filter and solvent" method which is more crude, but simple enough to understand basic concepts.
Melissa
what is esterification?
Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester(-COOR) as the reaction product....
Johnson
pls i dont know chemistry wat shall i do?
Chancha
Please...what do you mean by you don't know chemistry..can you explain further
Johnson
I am afraid you may end up injuring yourself working with these chemical processes with limited lab experience. Please be extremely careful. Research chem analysis, precedure and equipment.
Melissa
Pls can I be enlighten about boys law on chemistry
samuel
how we Learn full periodic table
how
Imran
Hello guys am new here my name is Angel from Nigeria how are u guys doing?
Gud am from Nigeria too my name is sav
Michael
explain the atomic orbital
2nacl➡️2na+cl2 2.58.5g 22.4l
what is neclear energy
nuclear energy is the energy released during nuclear fission or fusion.especially when used to generate electricity
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