Whenever any substance is put in to fire it burns and changes into ash. But asbestos is one such material that does not burn in fire. That is why the fire fighters wear clothes made from asbestos when fighting large fires. In fact their clothes, shoes, gloves, helmets etc. are all made from the fibres of this material.
Asbestos is a Greek word which means ‘inextinguishable’ or ‘unquenchable’. The invention of this material is not new. The Romans used asbestos sheets 2,000 years ago for wrapping dead bodies in order to preserve them.
This material is obtained from mines. It is formed by the dissociation of olivine. Olivines are the silicates of calcium and magnesium. Due to certain chemical reactions in the mines, olivine changes into fibres of asbestos. Asbestos obtained from mines is first dried and then its fibres are separated with the help of machines. These fibres are woven into threads and ropes which are then used for making clothes, sheets, mats etc.
Asbestos is a very useful material. It is used for making fire-proof clothes, paper and as heat-insulator in furnaces. It is also used for making fire proof tiles for buildings. In cold countries, water pipes coated with this material which serve as insulators preventing water from freezing in the pipes.
It is a bad conductor of both heat and electricity and is least affected by acids and alkalies. It does not burn even at a temperature of 2000°C to 3000°C. Some special varieties of asbestos are now available which do not burn even at 5000°C. This variety is used in research laboratories. The most common mineral of asbestos is chrysotile found in Canada and Russia.
Canada is credited with 75% of the total world production of asbestos. America manufactures maximum number of items from asbestos though the raw material obtained in this country is only 5%.