Extraction of Molybdenum

 

MOLYBDENUM (Mo)

Atomic number: 42

Colour: white platinum metal

Properties:

• Moderate hardness
• High thermal conductivity
• High resistance to corrosion
• Low expansion coefficient
• Low solubility in water

ORES:

Molybdenite (MoS₂) or molybdenite disulfide.

Extraction of molybdenum:

The extraction of thorium consists of many processes such as mining, processing, flotation and roasting.

Mining:

Molybdenum is extracted from molybdenite. By using the floating process, molybdenite is mixed with many reagents and it has been crushed and grinded. Then the minerals are separated from these gangue materials. It produces the higher amount of molybdenite and small amount of copper.

EXTRACTION AND REFINING PROCESS:

Roasting:

The higher amount of molybdenite is converted into molybdic oxide. This process is carried out in Nichols herreshoff type multiple hearth furnace. The concentrate molybdenite is fed from the top against a current heated air and gases blown from the bottom. This concentrate molybdenite is move through the rotary rakes to develop the chemical reaction. In this process the molybdenite disulphide is converted into the molybdic oxide. This molybdic oxide contains a minimum of molybdenum.

Upgrading:

The above reaction is controlled by adjusting the oxygen and water sprays that cool the furnace when necessary. This process is repeated continuously up to 650^oc. Because the temperature should not rise above 650^oc. At this point, upgrading process is performed by sublimation to produce pure MoO_3. This molybdic oxide is pure in order to suitable for the manufacture of the starting materials for all sorts of molybdenum chemicals such as ammonium molybdate (ADM), sodium molybdate. These compounds are obtained by chemically reacting pure MoO3 with aqueous ammonia or sodium hydroxide.

Metal production:

This process consists of two stages. First stage is the molybdic oxide and ammonium molybdate is reduced to dioxide. The second stage is converted into the metal powder. This process is carried out in electrically heated tubes. The hydrogen gas is introduced into the heated tubes. These two compounds are converted into the metallic molybdenum through the reduction process.

Uses:

• It is used in the manufacture of alloys because of its high corrosion resistance.
• Molybdenum powder is used as a fertilizer for some plants such as cauliflower.
• It is used for the preparation of aircrafts, light bulbs, military armor and industrial motors.
• Molybdenum is also helps to break down drugs and toxic substances that enter the body.
• Its strengthening of teeth.
• It helps in the production of a number of enzymes because it is trace mineral.