Hlin\u00edk je nemagnetick\u00fd a v\u00fdborne vedie elektrick\u00fd pr\u00fad; mo\u017eno ho tie\u017e \u013eahko tvarova\u0165 do r\u00f4znych tvarov, \u010d\u00edm sa zabezpe\u010d\u00ed odrazivos\u0165 svetla, ako aj ochrana pred \u017eiaren\u00edm a odolnos\u0165 proti kor\u00f3zii.<\/p>\n
Hlin\u00edk sa z\u00edskava z bauxitovej rudy, pomenovanej pod\u013ea miesta jej objavenia v ju\u017enom Franc\u00fazsku, a tvor\u00ed pribli\u017ene 8 % zemskej k\u00f4ry.<\/p>\n
Hlin\u00edk (be\u017ene ozna\u010dovan\u00fd aj v severoamerickej angli\u010dtine) je prvok so symbolom Al a at\u00f3mov\u00fdm \u010d\u00edslom 13. Hlin\u00edk je m\u00e4kk\u00fd, tv\u00e1rny kov, ktor\u00fd sa d\u00e1 odlieva\u0165, obr\u00e1ba\u0165 a lisova\u0165. V\u010faka svojej odolnosti vo\u010di kor\u00f3zii a n\u00edzkej hmotnosti sa dobre pou\u017e\u00edva na odlievanie, obr\u00e1banie a lisovanie. Okrem toho je v\u010faka svojej tepelnej a elektrickej vodivosti mimoriadne vhodn\u00fd. Napokon, tento nemagnetick\u00fd prvok sa m\u00f4\u017ee pochv\u00e1li\u0165 len jedn\u00fdm stabiln\u00fdm izotopom.<\/p>\n
Hlin\u00edk, druh\u00fd najroz\u0161\u00edrenej\u0161\u00ed kov v zemskej k\u00f4re, sa za\u010dal vyr\u00e1ba\u0165 vo v\u00fdznamn\u00fdch komer\u010dn\u00fdch mno\u017estv\u00e1ch len ned\u00e1vno. Hlin\u00edk mo\u017eno n\u00e1js\u0165 v mnoh\u00fdch priemyseln\u00fdch odvetviach, ktor\u00e9 vyr\u00e1baj\u00fa mili\u00f3ny r\u00f4znych v\u00fdrobkov vyu\u017e\u00edvaj\u00facich hlin\u00edk - od dopravn\u00fdch a stavebn\u00fdch aplik\u00e1ci\u00ed, kde je rozhoduj\u00faca n\u00edzka hmotnos\u0165 a pevnos\u0165, a\u017e po spotrebn\u00e9 predmety dlhodobej spotreby, ako s\u00fa spotrebi\u010de a kuchynsk\u00e9 n\u00e1\u010dinie. Hr\u00e1 d\u00f4le\u017eit\u00fa \u00falohu v glob\u00e1lnych ekonomik\u00e1ch ako k\u013e\u00fa\u010dov\u00fd hospod\u00e1rsky zdroj.<\/p>\n
\u010cist\u00fd hlin\u00edk sa v pr\u00edrode vyskytuje len zriedka a \u010dasto sa mus\u00ed kombinova\u0165 s in\u00fdmi prvkami, aby sa vytvorili zliatiny, ktor\u00e9 maj\u00fa \u0161pecifick\u00e9 vlastnosti. Medzi be\u017en\u00e9 leguj\u00face kovy patria me\u010f, hor\u010d\u00edk, mang\u00e1n, krem\u00edk a c\u00edn; tieto zliatiny pom\u00e1haj\u00fa zvy\u0161ova\u0165 pevnos\u0165 a prid\u00e1vaj\u00fa \u010fal\u0161ie \u017eiaduce vlastnosti, ako je zvarite\u013enos\u0165 a obrobite\u013enos\u0165.<\/p>\n
N\u00edzka hustota a tuhos\u0165 hlin\u00edka z neho rob\u00ed ide\u00e1lny \u013eahk\u00fd kov s vynikaj\u00facou pevnos\u0165ou v \u0165ahu a zvarite\u013enos\u0165ou, ktor\u00fd je ve\u013emi tv\u00e1rny, a preto je vhodn\u00fd na tvarovanie do r\u00farok alebo uhlov. Hlin\u00edk sl\u00fa\u017ei aj ako dobr\u00fd vodi\u010d elektrickej energie a tepla, pri\u010dom druh\u00e1 vlastnos\u0165 je eloxovan\u00e1, aby odol\u00e1vala kor\u00f3zii; navy\u0161e je v\u010faka svojej prirodzenej reflexnej povahe vhodn\u00fd na osvet\u013eovacie aplik\u00e1cie alebo zrkadl\u00e1.<\/p>\n
\u013dudstvo vyu\u017e\u00edvalo zl\u00fa\u010deniny hlin\u00edka po st\u00e1ro\u010dia, ale a\u017e priemyseln\u00e1 revol\u00facia umo\u017enila, aby sa hlin\u00edk stal \u013eah\u0161ie dostupn\u00fdm prvkom. Alumen, ktor\u00fd sa sklad\u00e1 z pota\u0161ov\u00e9ho hlin\u00edka (zl\u00fa\u010denina s\u00edranu hlinito-draseln\u00e9ho), sa dlho pou\u017e\u00edval ako farbivo a liek; jeho n\u00e1zov poch\u00e1dza z latin\u010diny alumen (\u010do v latin\u010dine znamen\u00e1 alkalick\u00fd) sa dnes be\u017ene pou\u017e\u00edva aj na v\u00fdrobu zubnej pasty a mydla; nadmern\u00e9 koncentr\u00e1cie v\u0161ak m\u00f4\u017eu v\u00fdrazne po\u0161kodi\u0165 bunky a zmeni\u0165 funkciu membr\u00e1n.<\/p>\n
Hlin\u00edk je jedn\u00fdm z najpevnej\u0161\u00edch dostupn\u00fdch kovov a m\u00f4\u017ee sa pochv\u00e1li\u0165 neuverite\u013en\u00fdm pomerom pevnosti a hmotnosti, ako aj dobr\u00fdmi hygienick\u00fdmi vlastnos\u0165ami a recykla\u010dn\u00fdmi procesmi, ktor\u00e9 umo\u017e\u0148uj\u00fa udr\u017eate\u013enej\u0161ie rie\u0161enia. Hlin\u00edk m\u00e1 tie\u017e vlastnosti odolnosti vo\u010di kor\u00f3zii a vodivosti, v\u010faka \u010domu je okrem in\u00e9ho ob\u013e\u00faben\u00fd pri kuchynskom n\u00e1rad\u00ed a pouli\u010dnom osvetlen\u00ed.<\/p>\n
Hlin\u00edk je m\u00e4kk\u00fd a z\u00e1rove\u0148 tv\u00e1rny, tak\u017ee sa d\u00e1 \u013eahko formova\u0165 do zlo\u017eit\u00fdch \u0161trukt\u00far s relat\u00edvne minim\u00e1lnym \u00fasil\u00edm. Okrem toho jeho kompaktn\u00e1 povrchov\u00e1 vrstva oxidu poskytuje ochranu pred kor\u00f3ziou. T\u00e1to pevne viazan\u00e1 vrstva navy\u0161e sp\u00f4sobuje, \u017ee hlin\u00edk je nerozpustn\u00fd vo vode, ale stabiln\u00fd na vzduchu; navy\u0161e jeho taviace a odlievacie schopnosti robia z hlin\u00edka mimoriadne \u013eahk\u00fd netoxick\u00fd materi\u00e1l vhodn\u00fd na mnoh\u00e9 pou\u017eitia.<\/p>\n
Hoci je hlin\u00edk vo v\u0161eobecnosti slab\u0161\u00ed ako oce\u013e, st\u00e1le dok\u00e1\u017ee odola\u0165 zna\u010dnej sile a hmotnosti bez toho, aby sa deformoval alebo oh\u00fdbal pod tlakom. Nane\u0161\u0165astie v\u0161ak jeho m\u00e4kk\u00e1 povaha sp\u00f4sobuje, \u017ee je n\u00e1chylnej\u0161\u00ed na prelia\u010diny, prelia\u010diny a \u0161krabance ako jeho oce\u013eov\u00fd n\u00e1protivok.<\/p>\n
\u010cist\u00fd hlin\u00edk na komer\u010dn\u00e9 pou\u017eitie m\u00e1 pevnos\u0165 v \u0165ahu 90 MPa a m\u00f4\u017ee by\u0165 \u010falej zosilnen\u00fd spracovan\u00edm za studena. Okrem toho jeho legovanie s prvkami, ako je me\u010f, mang\u00e1n, krem\u00edk a \u017eelezo v ur\u010dit\u00fdch percent\u00e1ch, \u010falej zvy\u0161uje jeho \u0165a\u017enos\u0165, zatia\u013e \u010do kalenie pri pr\u00e1ci rob\u00ed zliatiny e\u0161te pevnej\u0161\u00edmi.<\/p>\n
Hlin\u00edk m\u00e1 at\u00f3mov\u00e9 \u010d\u00edslo 13 a z h\u013eadiska v\u00fdskytu na Zemi je na tre\u0165om mieste za kysl\u00edkom a krem\u00edkom. Hoci sa hlin\u00edk nikdy nevyskytuje v pr\u00edrode v kovovej forme, jeho chemick\u00e9 vlastnosti umo\u017e\u0148uj\u00fa vytv\u00e1ra\u0165 zl\u00fa\u010deniny, ako je napr\u00edklad hlin\u00edk, ktor\u00fd sa pou\u017e\u00edva v syst\u00e9moch na \u010distenie vody. A\u017e v roku 1825 d\u00e1nsky fyzik Hans Christian Orsted \u00faspe\u0161ne vyrobil ne\u010dist\u00fa formu reakciou bezvod\u00e9ho chloridu hlinit\u00e9ho s drasl\u00edkom; nesk\u00f4r v tom istom roku sa Friedrichovi Wohlerovi podarilo z\u00edska\u0165 \u010dist\u00fd kovov\u00fd hlin\u00edk.<\/p>\n
Hlin\u00edk je jedn\u00fdm z najroz\u0161\u00edrenej\u0161\u00edch prvkov na Zemi, ktor\u00fd sa prirodzene vyskytuje v hornin\u00e1ch a veget\u00e1cii na pevnin\u00e1ch aj vo vodn\u00fdch ploch\u00e1ch. Hoci sa hlin\u00edk v pr\u00edrode nikdy nevyskytuje v \u010distom stave, preto\u017ee sa \u013eahko sp\u00e1ja s kysl\u00edkom a in\u00fdmi prvkami za vzniku zl\u00fa\u010den\u00edn, \u010do z tohto kovu rob\u00ed ve\u013emi m\u00e4kk\u00fd, tv\u00e1rny, kor\u00f3zii odoln\u00fd, \u013eahk\u00fd, elektricky vodiv\u00fd ne\u017eelezn\u00fd kov s jednou z najvy\u0161\u0161\u00edch dostupn\u00fdch hodn\u00f4t elektrickej vodivosti na v\u00fdrobu tenk\u00fdch plechov a f\u00f3li\u00ed.<\/p>\n
N\u00edzka hmotnos\u0165 a tv\u00e1rnos\u0165 hlin\u00edka z neho robia univerz\u00e1lny kon\u0161truk\u010dn\u00fd materi\u00e1l, preto\u017ee ho mo\u017eno pou\u017ei\u0165 v nosn\u00fdch aj nenosn\u00fdch kon\u0161trukci\u00e1ch. Okrem toho sa v\u010faka svojej tvarovate\u013enosti s ob\u013eubou pou\u017e\u00edva na v\u00fdrobu lietadiel, karos\u00e9ri\u00ed automobilov, obkladov a stre\u0161n\u00fdch kryt\u00edn, hrncov a panv\u00edc, ako aj spotrebn\u00fdch v\u00fdrobkov, napr\u00edklad hrncov a panv\u00edc. Hlin\u00edkov\u00e9 zliatiny m\u00f4\u017eu tie\u017e poskytova\u0165 jedine\u010dn\u00e9 vlastnosti prisp\u00f4soben\u00e9 \u0161peci\u00e1lne pre ur\u010dit\u00e9 aplik\u00e1cie.<\/p>\n
Pri v\u00fdrobe hlin\u00edka sa zvy\u010dajne pou\u017e\u00edva Bayerov proces, pri ktorom sa rozdrven\u00e1 bauxitov\u00e1 hornina rozdrv\u00ed a postrieka vodou, \u010d\u00edm sa odstr\u00e1ni \u00edl a \u010dastice oxidu kremi\u010dit\u00e9ho, a potom sa vysu\u0161\u00ed v peci a zmie\u0161a s uhli\u010ditanom sodn\u00fdm a rozdrven\u00fdm v\u00e1pnom na vznik oxidu hlinit\u00e9ho.<\/p>\n
Bauxit je hojn\u00e1 a n\u00e1kladovo efekt\u00edvna surovina na v\u00fdrobu hlin\u00edka, ale proces tavenia si vy\u017eaduje energeticky n\u00e1ro\u010dn\u00e9 oper\u00e1cie, pri ktor\u00fdch sa uvo\u013e\u0148uj\u00fa sklen\u00edkov\u00e9 plyny. Preto sa v\u00e4\u010d\u0161ina svetov\u00fdch taviarn\u00ed nach\u00e1dza v krajin\u00e1ch s dostatkom elektrickej energie; mnoh\u00e9 hlinik\u00e1rne boli tie\u017e postaven\u00e9 na brehoch jazier, aby sa v nich zachyt\u00e1vala morsk\u00e1 voda, ktor\u00e1 sa vyu\u017e\u00edva v procesoch s cie\u013eom zn\u00ed\u017ei\u0165 emisie a z\u00e1rove\u0148 zv\u00fd\u0161i\u0165 \u00fa\u010dinnos\u0165.<\/p>\n
Hlin\u00edk je striebornobiely kov z 13. skupiny periodickej tabu\u013eky prvkov, ktor\u00fd tvor\u00ed tretinu hmotnosti zemskej k\u00f4ry a je tret\u00edm najroz\u0161\u00edrenej\u0161\u00edm prvkom po kysl\u00edku a krem\u00edku. Hoci sa hlin\u00edk v pr\u00edrode vyskytuje ako kov v \u010distom stave, jeho pr\u00edtomnos\u0165 \u010dasto tvoria miner\u00e1ly, ako je bauxit. Hlin\u00edk je jedn\u00fdm z troch celosvetovo najroz\u0161\u00edrenej\u0161\u00edch ne\u017eelezn\u00fdch kovov a tret\u00edm najroz\u0161\u00edrenej\u0161\u00edm prvkom.<\/p>\n
Hlin\u00edk m\u00e1 mnoho \u017eiaducich vlastnost\u00ed a aplik\u00e1ci\u00ed v priemysle. Je trikr\u00e1t \u013eah\u0161\u00ed ako \u017eelezo so zv\u00fd\u0161en\u00fdm pomerom pevnosti a hmotnosti, pri\u010dom zost\u00e1va pru\u017en\u00fd, odoln\u00fd, odoln\u00fd vo\u010di kor\u00f3zii, nemagnetizuje a m\u00e1 vynikaj\u00face vlastnosti elektrickej vodivosti - nehovoriac o jednom z najlacnej\u0161\u00edch komer\u010dne dostupn\u00fdch kovov! V\u010faka svojej v\u0161estrannosti sa hlin\u00edk okrem in\u00e9ho pou\u017e\u00edva na v\u00fdrobu n\u00e1dob, kuchynsk\u00e9ho n\u00e1\u010dinia, n\u00e1pojov\u00fdch plechoviek, trupov lietadiel a karos\u00e9ri\u00ed automobilov.<\/p>\n
Kovov\u00fd hlin\u00edk m\u00f4\u017ee pri vystaven\u00ed nepriazniv\u00e9mu prostrediu korodova\u0165, pri\u010dom vod\u00edkov\u00e9 i\u00f3ny napom\u00e1haj\u00fa tomuto procesu reakciou s molekulami kysl\u00edka za vzniku oxidu hlinit\u00e9ho. T\u00e1to reakcia je v\u0161ak vratn\u00e1 a povrch zostane stabiln\u00fd, pokia\u013e koncentr\u00e1cia vod\u00edka v roztoku neprekro\u010d\u00ed ur\u010dit\u00e9 prahov\u00e9 hodnoty; vtedy sa za\u010dne \u0161trbinov\u00e1 kor\u00f3zia a hydroxid hlinit\u00fd sa vyzr\u00e1\u017ea z roztoku a za\u010dne kor\u00f3ziu s\u00e1m od seba - tzv. \u0161trbinov\u00e1 kor\u00f3zia.<\/p>\n
Hlin\u00edk m\u00f4\u017ee podlieha\u0165 kor\u00f3zii v r\u00f4znych podmienkach prostredia vr\u00e1tane kysl\u00fdch, alkalick\u00fdch a chloridov\u00fdch roztokov. Kor\u00f3zia sa zvy\u010dajne za\u010d\u00edna r\u00fdchlo v trhlin\u00e1ch alebo prasklin\u00e1ch pred rozpusten\u00edm v elektrolyte za vzniku hydroxidu hlinit\u00e9ho rozpustn\u00e9ho vo vode; t\u00e1to forma kor\u00f3zie je obzvl\u00e1\u0161\u0165 roz\u0161\u00edren\u00e1 v morskom prostred\u00ed s vysokou koncentr\u00e1ciou chloridov.<\/p>\n
K rovnomernej kor\u00f3zii doch\u00e1dza u v\u00fdrobkov, ktor\u00e9 s\u00fa trvalo vystaven\u00e9 silne kysl\u00e9mu alebo z\u00e1sadit\u00e9mu prostrediu, alebo ke\u010f je ich povrch po\u0161kriaban\u00fd alebo obit\u00fd a z\u00e1kladn\u00fd materi\u00e1l je vystaven\u00fd p\u00f4sobeniu elektrolytov; tento typ kor\u00f3zie \u010dasto vedie k bodovej kor\u00f3zii alebo exfoli\u00e1cii (forma medzizrnovej kor\u00f3zie).<\/p>\n
Hlin\u00edk sa hojne vyskytuje v celej zemskej k\u00f4re, ale v pr\u00edrode sa nikdy nevyskytuje samostatne. Namiesto toho sa vyskytuje v kombin\u00e1cii s in\u00fdmi prvkami bu\u010f ako s\u00edran draselno-hlinit\u00fd (KAl(SO4)212H2O), alebo ako bauxity; tie s\u00fa \u010dervenohned\u00e9 horniny obsahuj\u00face zmesi hydroxidov a oxidov hlin\u00edka, ktor\u00e9 sa \u0165a\u017eia zo zeme a sprac\u00favaj\u00fa Bayerov\u00fdm procesom pred \u010fal\u0161ou rafin\u00e1ciou na \u010dist\u00fd hlin\u00edk na pou\u017eitie v r\u00f4znych aplik\u00e1ci\u00e1ch.<\/p>","protected":false},"excerpt":{"rendered":"
Aluminum is nonmagnetic and an excellent conductor of electricity; it can also be easily shaped into many different forms, providing […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"footnotes":""},"categories":[6],"tags":[],"class_list":["post-59","post","type-post","status-publish","format-standard","hentry","category-alumina-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/posts\/59","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/comments?post=59"}],"version-history":[{"count":1,"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/posts\/59\/revisions"}],"predecessor-version":[{"id":60,"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/posts\/59\/revisions\/60"}],"wp:attachment":[{"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/media?parent=59"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/categories?post=59"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aluminaceramics.net\/sk\/wp-json\/wp\/v2\/tags?post=59"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}