Geschichte Des Zinks INT En

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  Bericht Report  History of Zinc, its Production and Usage Dr. Marinanne Schönnenbeck/Frank Neumann Introduction Long before the discovery of zinc as a metal zinc ore !as already being used to roducethe co er#zinc alloy brass as !ell as zinc salts for medical ur oses. $b%ects made of brass are kno!n from &abylonia and 'ssyria from ())) &* and from +alestine dating from ,-)) # ,))) &*.he addition of zinc to co er for the first time !as roven by a iece of %e!ellery fromaround )) &* found on 0hodos. 'nd even if zinc !as used from that date to roducebrass for e1am le many centuries nevertheless assed until it could be identified as ametal. he name 2zinc2 only came into general use in the ,3th century follo!ing rediscovery of the material. 's zinc only ever occurs in Nature in the form of com ounds it !as initially roduced from carbonate of zinc a zinc salt. 4inc !as found to be es ecially suitable for alloys !ithother metals and !as therefore first of all em loyed to make coins. 'lthough zinc ores have been in use since the &ronze 'ge it !as not until very much later that zinc !as discovered to be an element i.e. a substance that cannot be broken do!n further. 4inc !as generally im orted from 5ndia until the end of the ,6th century and !as considered tobe very costly. Early production and usage in India and China Metallic zin c !as roduced in 5ndia around ,7)) 'D and the rocess is described as the roduction of a ne! metal similar to tin. 5t involved heating the zinc ore indirectly !ithcharcoal in a covered crucible. his roduced zinc va our !hich !as cooled by the ambient air in a condensation reci ient underneath the crucible. his is ho! metallic zinc!as formed 8 Fehler! Verweisuelle onnte nicht gefunden werden 9.5t !as Marco +olo 8,7-#,(7-9 from :enice !ho re orted the roduction of zinc o1ide in+ersia. 't this time the +ersians used a solution of zinc vitriol 84nS$ -  3; 7 $9 to treat eyeinflammations. 4inc sul hate 84nS$ - 9 is used in medicine as an adstringent and antise tic even today.&y ,(3- zinc had been recognised by the ;indus as a ne! metal the eighth kno!n inthat day and age and zinc roduction and trading !as already under!ay on a limitedscale.  Bericht Report   Fig. 1: In India around 1200 AD metallic zinc was  produced in a covered crucible. From there it  passed into a condensation recipient, where it was cooled b the ambient air. !according to abashi# <e also kno! of a modified rocess used in the rovince of 0a%asthan in the north!est of 5ndia during the eriod bet!een the ,7th and ,=th century. here tube#sha ed crucibles7 cm in length and , cm in diameter !ere e>ui ed !ith a tube of a smaller diameter.he crucibles !ere stacked in an oven !hich !as heated !ith charcoal !ith the hel of bello!s. he zinc va our then condensed in the tubes. his method rovided for thee1traction of around , million tons of metallic zinc and zinc o1ide ? as indicated by theresidues found at this site. Metallic zinc !as used to roduce brass !hile the zinc o1ide!as destined for medical a lications. ' roduction rocess is described in ,3th century *hina 8 Fehler! Verweisuelle onntenicht gefunden werden 9 involving mi1ing zinc ore in individual crucibles !ith o!dered   charcoal. hey !ere then stacked u into a yramid sha e !ith coals bet!eenthe s aces. his entire structure !as heated until red#hot and then cooled do!n and broken a art. 4inc !ould be found in the middle as round lum s of metal. During the Ming dynasty 8,(=6#,=--9 *hina !as already using coins containing @@A zinc and ,A silver. he roduction of zinc increased and it !as e1 orted from 5ndia and *hina as far a!ay as Buro e.  Bericht Report   Fig. 2: $roduction o% zinc in 1&th centur 'hina, using crucibles stac(ed into pramids with charcoal between the spaces. A%ter being heated until it was red)hot and subse*uent cooling, the slag was bro(en apart to %ind the  zinc in the middle. !according to abashi# Early production and usage in Europe he Creek geogra her and historian Strabo 8=- &* to 7( 'D9 comments that only 2*y rian ore2 contained the necessary constituents for the roduction of brass. ;e also mentions a mineral that turns into iron !hen burnt and if then melted in an oven !ith certain constituents 2mock silver2 8i.e. zinc9 could be distilled. his material could itself be used to obtain brass by alloying it !ith co er.5t is assumed that in 0ome at the time of 'ugustus 8=( &* to ,- 'D9 brass !as roducedby heating u a mi1ture of o!dered calamine charcoal and granules of co er !hile ensuring that the tem erature remained belo! the melting oint of co er. $nce the resulting zinc va our had reacted !ith the co er the tem erature !as increased so smelting brass. he similarity bet!een brass and gold robably also s urred on numerous alchemists to try to roduce gold from other metals. 5n the middle of the ,(th century the natural scientist hiloso her and theologist 'lbertus Magnus 8,7))#,76)9 describes ? !ithout even kno!ing of zinc as a metal ? a rocess that allo!ed the level of zinc in brass to be increased during smelting. his consisted of scattering crushed glass over the molten mass to make slag. his revented the zinc esca ing from this mass as va our so increasing the zinc content of the brass. he !orks 2De natura fossilium2 8,-=9 and 2De re metallica2 8 ublished in ,=9 !ere !ritten by Ceorgius 'gricola 8,-@-#,9 the humanist hysician and mineralogist from Sa1ony. ;e describes ho! during the e1traction of silver and lead in Cermanys ;arz Mountains a !hite metal !as de osited on the !alls of the furnace and !as used as an imitation for gold. he hysician and natural scientist +hili us heo hrastus +aracelsus8,-@(#,-(9 !as the first to clearly identify 2zincum2 8zinc9 as a ne! metal !hich differed  Bericht Report  from the other metals kno!n at the time in terms of its ro erties. During this eriod zinc !as still mainly im orted from the $rient.he !ord 2zinc2 ossibly comes from the +ersian 2sing2 !hich means 2stone2. $n the other hand it might also derive from the Cerman term 24incken2 !hich !as a reference to the %agged sha e of calamine ore.  Fig. +: inc minerals !%rom IA: $oc(et -uide#. $ne ma%or difficulty during the e1traction of zinc at the time !as its tendency to already va orise belo! the smelting tem erature !hich is over ,))) E*. <ith the ingress of air the zinc then combusts into zinc o1ide. During smelting the resulting zinc va our thus hadto be ca tured and condensed !ithout the ingress of air to ensure the de osit of metallic zinc.5n ,3-= the &erlin chemist 'ndreas Sigismund Marggraf 8,3)@#,3679 succeeded in isolating zinc as a ure metal. 5n his e1 eriment Marggraf heated zinc ores from various sources together !ith charcoal in covered crucibles and obtained metallic zinc from all of them. ;ere he demonstrated not only that the lead ores from 0ammelsberg in the ;arz like!ise contained zinc but also that zinc can be e1tracted from s halerite.Shortly before this date the S!edish scientist 'nton von S!ab 8,3)(#,3=69 succeeded indistilling zinc. 's the va ours ascended u !ards during this rocess before assing intothe reci ient it !as kno!n as distillation 2 er ascendum2.5n the ,6th century the metal !as e1tracted on an increased scale in Bngland  er Silesia and in the 'achen#LiGge region.he rocess of smelting zinc in a retort oven !as observed in *hina by an Bnglishman <illiam *ham ion 8,3)@#,36@9. ;e then develo ed a rocess using a vertical retort oven8 Fehler! Verweisuelle onnte nicht gefunden werden 9. his involved lacing zinc ore!ith coal in covered crucibles !ith an o ening at the bottom. he melted zinc then ran into an iron i e e1tending into a cooling chamber underneath. he metallic zinc !as
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