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Ch.4. Asbestos in the Environment  Introduction  Properties and uses  Brief history  Environmental hazards.

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Presentation on theme: "Ch.4. Asbestos in the Environment  Introduction  Properties and uses  Brief history  Environmental hazards."— Presentation transcript:

1 Ch.4. Asbestos in the Environment  Introduction  Properties and uses  Brief history  Environmental hazards

2  Introduction Asbestos:  “inquenchable” “inextinguishable” Fibrous silicate minerals: serpentine & amphiboles ○ White, brown, blue & others tremolite crocidolite chrysotile Asbestos fibre From

3  Properties & Use Properties: ○ Mineral: insulation (heat, electricity), resistance against fire & chemical reaction, incombustibility ○ Fibre: flexibility, capability of being woven, sound- absorbing Uses ○ (See the table on the next page)

4 PropertiesApplication examples Fire resistance, flame retardance, heat insulation Building materials- interior and outside Fire-proof materials, e.g. cloths Seals for heaters and ovens Heat insulators Electric insulation Insulators for pipes and electrical devices Commutators Resistance against chemical reactions (corrosion) Chemical filters, Paints Gaskets Experimental apparatuses Sound absorptionSound absorbing board

5 5  Brief History B.C. ca. 3,000 Scandinavian remains – used in porcelain and filler among the logs 1C : Greek island Evvoia – Asbestos mining querry Early Greek-Roman: unflammable clothes and building materials Pliny the Elder: Thought to be used for the protection from the curse Pliny the Elder (23-79), a.k.a. Caius Plinius Secundus, Gaius Plinius Secundis. Author of the grand encyclopedia "Naturalis Historiae".

6 Ancient Egyptian: Used for Parao’s mummy Ancient Persian: Imported from China, Used for the cloths for deaths, thought as feather of saramanda (phoenix) Others: Lamp wick of tomb, Cure for itching Saramanda on a tile from ancient Iranian heritage

7 Marco Polo ( ): “Livres des merveilles du monde”  Clothes being cleaned in fire?

8 8 In medieval times, asbestos was frequently used for the insulation of armor Some fraud merchants made cross with asbestos and deceive people with it as if that was a part of the cross on which Jesus Christ was nailed (hung, executed)

9 19C: Industrial revolution also trigger modern application of asbestos ○ Used as heat insulator in USA & Canada in 1860’s ○ First commercial asbestos mine in Quebec, Canada, in C: rapid increase of asbestos consumption After 1970’s: Health threats (hazards) by asbestos became obvious  invoke lot of regulations against asbestos usage. Ban of asbestos usgae  Sudden decrease of asbestos consumption

10 Asbestos production and consumption Global production (10,000 ton/year) Japan (ton/year) China Korea

11 Now, the usage of asbestos is banned or limited in most countries For Korea, ○ From , asbestos is banned to be used in any industrial product ○ From , any product containing asbestos is banned to import, produce, or use.

12 World Asbestos Resources CountryReserve Base (By Principal Countries) BrazilModerate CanadaLarge ChinaLarge KazakhstanLarge RussiaLarge USALarge ZimbabweModerate Other CountriesLarge World TotalLarge Source : Mineral Commodity Summaries, 2004.

13 World Asbestos Producers Country (By Principal Countries)Production of Asbestos(in '000' tonnes) Brazil Canada China258220(e)210(e) Kazakhstan Russia735775(e)878(e) Zimbabwe Other Countries World Total Source : World Mineral Production

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