Aluminium is the third most abundant element in the Earth's crust and constitutes 7.3% by mass. In nature however it only exists in very stable combinations with other materials (particularly as silicates and oxides) and it was not until 1808 that its existence was first established. It took many years of painstaking research to "unlock" the metal from its ore and many more to produce a viable, commercial production process. Pure aluminium is a silvery-white metal with many desirable characteristics. It is light, nontoxic (as the metal), nonmagnetic and nonsparking. Aluminium has only been produced commercially for 146 years and is still a very young metal. Mankind has been using copper, lead and tin for thousands of years and yet today more aluminium is produced than all other non-ferrous metals combined. Annual primary production in 1999 was about 24 million tonnes and secondary - recycled - production to some 7 million tonnes. The total of some 31 million tonnes compares with 14.1 million tonnes of copper , 6.0 million tonnes of lead and 0.2 million tonnes of tin.

Manufacturing Process s

Two unknown young scientists, Paul Louis Toussaint Héroult (France) and Charles Martin Hall (USA), working separately and unaware of each other's work, simultaneously invent a new electrolytic process, the Hall-Héroult process, which is the basis for all aluminium production today. They discovered that if they dissolved aluminium oxide (alumina) in a bath of molten cryolite and passed a powerful electric current through it, then molten aluminium would be deposited at the bottom of the bath.

Manufacture of aluminium involves the following processes:

• Refinining of Bauxite Ore to form Alumina
• Electrolysis of Alumina to form Aluminium
• Casting of Molten Aluminium to form ingots.

Risk Management

Molten Metal Explosions

The risk can be controlled by designing systems which prevent the introduction of water or reactive chemicals into molten metal, the transfer of molten metal onto wetted surfaces, and/or the inadvertent contamination of tools and vessels with water and reactive chemicals. Amine Epoxy Coatings are available these days create an effective safety barrier between a wet substrate and molten aluminium to reduce the risk of molten aluminium explosion.

Impact Damage

The risk of objects and loads falling from stacks can be controlled by designing inherently stable structures and stacking configurations, providing adequate stacking and lifting equipment and separating stacks from vehicle traffic and/or personnel.

Handling of Hazardous

Goods Reduce inventory of dangerous goods storage on site (eg spent potlining and dross). Processing of spent potlining material to reduce Dangerous Goods Accumulation is suggested. In particular, the structures used for the storage, handling and transport of spent potlining and dross should be designed in such a way to prevent the inward leakage of water from all credible events, be adequately ventilated to prevent the accumulation of flammable mixtures in air, include explosion (pressure relief) protection systems, and be located away from potential sources of ignition and general work areas.

Important

The information set out in this document constitutes a set of general guidelines and should not be construed or relied upon as specialist advice. Independent legal advice should always be sought. Therefore Risktechnik accepts no responsibility towards any person relying upon these Risk Management Guides nor any liability whatsoever for the accuracy of data supplied by another party or the consequences of reliance upon it.