Design of Sulfur recovery - Part 2

1.3 PROPERTIES OF SULPHUR:

PHYSICAL :

Atomic no                 :      16

Atomic mass             :      32.06 g /mol

Electronegativity      :      2.5

Density                     :      2.07g /cm ³ @ 20◦C

Boiling point            :      113◦C

Solubility                   :       It is insoluble in water , sparingly soluble              in alcohol and ether, readily soluble in carbon disulphide, chloroform, xylene, acetone , etc

CONDUCTIVITY : Sulphur is anon conductor of heat and electricity. however, a lump of Sulphur when rubbed by dry hand , or with a wool, becomes electrically charged .

  EFFECT OF HEAT : when heated, Sulphur undergoes a series of changes like evaporation .

CHEMICAL PROPERTIES:

1.     Sulphur exhibits oxidation numbers of -2,0,+2,+4 and +6

2.     Chemical properties of Sulphur- with Air or oxygen : When heated in air or oxygen, Sulphur first melts and then burns with a blue flame to form Sulphur dioxide and some traces of Sulphur trioxide.

3.     Sulphur also combines with most other elements. Sometimes it combines with them easily at room temperature. In other cases, if must be heated.

4.      The reaction between magnesium and Sulphur is typical. When the two elements are heated, they combine to form magnesium Sulphur (MgS).

Sulphur also combines with hydrogen gas. The compound formed in this reaction is hydrogen sulfide (H₂S).  Hydrogen sulphide has one of the best known odour of all compounds.  It smell like rotten eggs. Hydrogen sulfide is added to natural gas (methane) used in homes for cooking and heating. Methane is odorless. So the unique smell of hydrogen sulfide makes it easy to know when there is methane leak.

1.4 USES OF SULPHUR IN DAY TODAY LIFE :

Majority of Sulphur produced is used for production of Sulphuric acid which in turn is used for digesting phosphate rock to produce fertilizers.

Sulphur recovery reduces air pollution. It allows people to breath better, reduces acid rain.

Sulphur has relatively few uses as an element. One of the most important of those uses is in vulcanization. Vulcanization is the process of adding Sulphur to rubber to make it stiff and hard. It keeps the rubber from melting as it gets warmer.

Some powdered Sulphur is also used as an insecticide. It can be spread on plants to kill or drive away insects that feed on the plants.

Sulphur is an important fuel in pyrotechnic mixtures, because it is cheap and stable. It occurs in match heads, the most common  pyrotechnical device, and was an ingredient of black powder is a special mixture of 75% potassium nitrate,  15% charcoal, and 10% sulphur,  more or less. Other applications are making corrosion-resistant concrete which has great strength and is forst resistant, for solvents and in a host of other products of the chemical and pharmaceutical industries.

FACTS ABOUT  H₂S:

1.     It is highly toxic, colorless gas with of rotten eggs smell.

2.     It forms explosive mixture with air.

3.     Prolonged exposure to low concentration will dull the sense of smell.

4.     It dissolves in water and is very corrosive on carbon steel.

5.     It severely attacks carbon steel above 350◦C.