ZINC

ZINC

• Atomic number- 30
• Atomic mass- 65.39 amu
• Group 12
• Period 4
• Block D

Zin is the German word for Tin. It as discovered in 1746 by Andreas Marggraf. He was a German chemist from Berlin.

Zinc (Zn) is classified as a transition metal but is a diamagnetic. This means that zinc has no magnetic qualities. Zinc has an atomic size of 134 pm. It's a solid, bluish- silver dull metal that is fairly soft. On the MOHs scale, it's only a 2.5. 0 being talc and 10 being diamonds.
It's also very lustrous.

Untitled Slide

ZINC HAS HEXAGONAL CRYSTAL STRUCTURE

In a neutral atom there are..
30 protons
30 electrons
34 neutrons

There are five isotopes that form in zinc.

There are two ions that form in zinc. Each ions forms due to gaining or losing electrons, in this case it is because of gaining them.

-Electronegativity- Pauling scale 1.60
-Electron affinity- 0 KJ/mol
-Ionization Energy- 9.3942 ev
-Density- 7.13 g/cm3
-Conductivity- fair conductor of electricity

-Boiling point- 1180 K
-Melting point- 692.68 K
-Specific heat- 0.39 J g-1 K-1
-Oxidation state- +2
-Electron Configuration- 2-8-18-2

Untitled Slide

FLAMMABILITY

Solubility of zinc:
*this depends on the temperature and pH

Neutral solutions have no solubility with zinc
*as acidity increases, so does the solubility

CHEMICAL PROPERTIES

Untitled Slide

Zinc mines are mostly found in China, Peru, Australia, India, Canada and USA.

Untitled Slide

SOURCES

• Volcanic Hosted Massive Sulphides (VMS)
• Carbonated Hosted
• Sediment Hosted
• Intrusion Related

Mines:
Underground mines 80%, open pit 8%, both 12%

About 90% of zinc recovered is actually ZnS. This contains mostly sulphur but it also includes some silver, iron, ect..

STAGES OF MINING

ROASTING or SINTERING:
This removes the sulphur and other impurities from the zinc by heating it up to 900 degrees Celsius. This turns it into zinc oxide (ZnO) and sulphur dioxide. The sulphur dioxide gets converted to sulphur and is used later.

HYDROMETALLURGICAL PROCESS:
The zinc in the zinc oxide is separated using the sulphur acid from roasting.
PURIFACTION:
They add zinc dust and then they send it through electrical currents.
It's then stripped, dried, melted and casted into ingots.

Untitled Slide

PYROMETALLURGICAL PROCESS:
Lead is added to the zinc, turning it into the metal. They use carbon for this process. This is very pricey and they energy cost is great.

Uses:
Metal coatings
Rust protectant
Alloys..
-Nickel
-Silver
-Brass
-Aluminum

Untitled Slide

Untitled Slide