Hlin\u00edk je nemagnetick\u00fd a v\u00fdborn\u011b vede elektrick\u00fd proud; lze jej tak\u00e9 snadno tvarovat do mnoha r\u016fzn\u00fdch forem, co\u017e zaji\u0161\u0165uje odrazivost sv\u011btla, ochranu p\u0159ed z\u00e1\u0159en\u00edm a odolnost proti korozi.<\/p>\n
Hlin\u00edk se z\u00edsk\u00e1v\u00e1 z bauxitov\u00e9 rudy, pojmenovan\u00e9 podle m\u00edsta jej\u00edho objevu v ji\u017en\u00ed Francii, a tvo\u0159\u00ed p\u0159ibli\u017en\u011b 8 % zemsk\u00e9 k\u016fry.<\/p>\n
Hlin\u00edk (v severoamerick\u00e9 angli\u010dtin\u011b tak\u00e9 b\u011b\u017en\u011b ozna\u010dovan\u00fd jako Al) je prvek se symbolem Al a atomov\u00fdm \u010d\u00edslem 13. Hlin\u00edk je m\u011bkk\u00fd, tv\u00e1rn\u00fd kov, kter\u00fd lze odl\u00e9vat, obr\u00e1b\u011bt a lisovat. D\u00edky sv\u00e9 odolnosti proti korozi a n\u00edzk\u00e9 hmotnosti se dob\u0159e hod\u00ed k odl\u00e9v\u00e1n\u00ed, obr\u00e1b\u011bn\u00ed a vytla\u010dov\u00e1n\u00ed. Krom\u011b toho je d\u00edky sv\u00e9 tepeln\u00e9 a elektrick\u00e9 vodivosti mimo\u0159\u00e1dn\u011b vhodn\u00fd. A kone\u010dn\u011b, tento nemagnetick\u00fd prvek se m\u016f\u017ee pochlubit pouze jedn\u00edm stabiln\u00edm izotopem.<\/p>\n
Hlin\u00edk, druh\u00fd nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00ed kov v zemsk\u00e9 k\u016f\u0159e, se teprve ned\u00e1vno za\u010dal vyr\u00e1b\u011bt ve v\u00fdznamn\u00e9m komer\u010dn\u00edm mno\u017estv\u00ed. Hlin\u00edk lze nal\u00e9zt v mnoha pr\u016fmyslov\u00fdch odv\u011btv\u00edch, kter\u00e1 vyr\u00e1b\u011bj\u00ed miliony r\u016fzn\u00fdch v\u00fdrobk\u016f vyu\u017e\u00edvaj\u00edc\u00edch hlin\u00edk - od dopravn\u00edch a stavebn\u00edch aplikac\u00ed, kde je rozhoduj\u00edc\u00ed n\u00edzk\u00e1 hmotnost a pevnost, a\u017e po spot\u0159ebn\u00ed zbo\u017e\u00ed dlouhodob\u00e9 spot\u0159eby, jako jsou spot\u0159ebi\u010de a kuchy\u0148sk\u00e9 n\u00e1dob\u00ed. Jako kl\u00ed\u010dov\u00fd ekonomick\u00fd zdroj hraje z\u00e1sadn\u00ed roli v glob\u00e1ln\u00edch ekonomik\u00e1ch.<\/p>\n
\u010cist\u00fd hlin\u00edk se v p\u0159\u00edrod\u011b vyskytuje jen z\u0159\u00eddka a \u010dasto se mus\u00ed kombinovat s jin\u00fdmi prvky, aby vznikly slitiny, kter\u00e9 maj\u00ed specifick\u00e9 vlastnosti. Mezi b\u011b\u017en\u00e9 leguj\u00edc\u00ed kovy pat\u0159\u00ed m\u011b\u010f, ho\u0159\u010d\u00edk, mangan, k\u0159em\u00edk a c\u00edn; tyto slitiny pom\u00e1haj\u00ed zlep\u0161it pevnost a p\u0159id\u00e1vaj\u00ed dal\u0161\u00ed \u017e\u00e1douc\u00ed vlastnosti, jako je sva\u0159itelnost a obrobitelnost.<\/p>\n
Hlin\u00edk je d\u00edky sv\u00e9 n\u00edzk\u00e9 hustot\u011b a tuhosti ide\u00e1ln\u00edm lehk\u00fdm kovem s vynikaj\u00edc\u00ed pevnost\u00ed v tahu a sva\u0159itelnost\u00ed a je vysoce tv\u00e1rn\u00fd, tak\u017ee je vhodn\u00fd pro tvarov\u00e1n\u00ed do trubek nebo \u00faheln\u00edk\u016f. Hlin\u00edk tak\u00e9 slou\u017e\u00ed jako dobr\u00fd vodi\u010d elekt\u0159iny a tepla, p\u0159i\u010dem\u017e druh\u00e1 vlastnost eloxov\u00e1n\u00ed odol\u00e1v\u00e1 korozi; nav\u00edc je d\u00edky sv\u00e9 p\u0159irozen\u00e9 odrazivosti vhodn\u00fd pro osv\u011btlovac\u00ed aplikace nebo zrcadla.<\/p>\n
Lidstvo vyu\u017e\u00edvalo slou\u010deniny hlin\u00edku po stalet\u00ed, ale teprve pr\u016fmyslov\u00e1 revoluce umo\u017enila, aby se hlin\u00edk stal dostupn\u011bj\u0161\u00edm prvkem. Alumen, tvo\u0159en\u00fd hlinitanem draseln\u00fdm (slou\u010denina s\u00edranu hlinito-draseln\u00e9ho), se dlouho pou\u017e\u00edval jako prost\u0159edek k fixaci barviv a v l\u00e9ka\u0159stv\u00ed; jeho n\u00e1zev poch\u00e1z\u00ed z latiny alumen (co\u017e v latin\u011b znamen\u00e1 alkalick\u00fd) se dnes tak\u00e9 hojn\u011b pou\u017e\u00edv\u00e1 k v\u00fdrob\u011b zubn\u00ed pasty a m\u00fddla; nadm\u011brn\u00e9 koncentrace v\u0161ak mohou po\u0161kodit bu\u0148ky a v\u00fdrazn\u011b zm\u011bnit funkci membr\u00e1n.<\/p>\n
Hlin\u00edk je jedn\u00edm z nejpevn\u011bj\u0161\u00edch dostupn\u00fdch kov\u016f a m\u016f\u017ee se pochlubit neuv\u011b\u0159iteln\u00fdm pom\u011brem pevnosti a hmotnosti, jako\u017e i dobr\u00fdmi hygienick\u00fdmi vlastnostmi a recykla\u010dn\u00edmi procesy, kter\u00e9 umo\u017e\u0148uj\u00ed udr\u017eiteln\u011bj\u0161\u00ed \u0159e\u0161en\u00ed. Hlin\u00edk m\u00e1 tak\u00e9 odolnost proti korozi a vodivost, d\u00edky \u010demu\u017e je obl\u00edben\u00fd mimo jin\u00e9 u kuchy\u0148sk\u00e9ho n\u00e1\u010din\u00ed a pouli\u010dn\u00edho osv\u011btlen\u00ed.<\/p>\n
Hlin\u00edk je m\u011bkk\u00fd a tv\u00e1rn\u00fd, tak\u017ee se d\u00e1 snadno tvarovat do slo\u017eit\u00fdch struktur s relativn\u011b mal\u00fdm \u00fasil\u00edm. Jeho kompaktn\u00ed povrchov\u00e1 vrstva oxidu nav\u00edc poskytuje ochranu p\u0159ed koroz\u00ed. D\u00edky t\u00e9to pevn\u011b v\u00e1zan\u00e9 vrstv\u011b je hlin\u00edk nav\u00edc nerozpustn\u00fd ve vod\u011b, ale stabiln\u00ed na vzduchu; nav\u00edc jeho schopnost taven\u00ed a odl\u00e9v\u00e1n\u00ed \u010din\u00ed z hlin\u00edku extr\u00e9mn\u011b lehk\u00fd netoxick\u00fd materi\u00e1l vhodn\u00fd pro mnoho pou\u017eit\u00ed.<\/p>\n
A\u010dkoli je hlin\u00edk obecn\u011b slab\u0161\u00ed ne\u017e ocel, p\u0159esto vydr\u017e\u00ed zna\u010dnou s\u00edlu a hmotnost, ani\u017e by se deformoval nebo oh\u00fdbal pod tlakem. Bohu\u017eel je v\u0161ak d\u00edky sv\u00e9 m\u011bkk\u00e9 povaze n\u00e1chyln\u011bj\u0161\u00ed k prom\u00e1\u010dknut\u00ed, prom\u00e1\u010dknut\u00ed a po\u0161kr\u00e1b\u00e1n\u00ed ne\u017e jeho ocelov\u00fd prot\u011bj\u0161ek.<\/p>\n
\u010cist\u00fd hlin\u00edk pro komer\u010dn\u00ed pou\u017eit\u00ed m\u00e1 pevnost v tahu 90 MPa a m\u016f\u017ee b\u00fdt d\u00e1le zpevn\u011bn zpracov\u00e1n\u00edm za studena. Nav\u00edc jeho legov\u00e1n\u00ed s prvky, jako je m\u011b\u010f, mangan, k\u0159em\u00edk a \u017eelezo, v ur\u010dit\u00fdch procentech d\u00e1le zvy\u0161uje jeho ta\u017enost, zat\u00edmco kalen\u00edm se slitiny st\u00e1vaj\u00ed je\u0161t\u011b pevn\u011bj\u0161\u00edmi.<\/p>\n
Hlin\u00edk m\u00e1 atomov\u00e9 \u010d\u00edslo 13 a na Zemi se \u0159ad\u00ed na t\u0159et\u00ed m\u00edsto za kysl\u00edk a k\u0159em\u00edk. Hlin\u00edk se sice v p\u0159\u00edrod\u011b nikdy nevyskytuje v kovov\u00e9 form\u011b, ale d\u00edky sv\u00fdm chemick\u00fdm vlastnostem vytv\u00e1\u0159\u00ed slou\u010deniny, jako je hlin\u00edk, kter\u00fd se pou\u017e\u00edv\u00e1 v syst\u00e9mech na \u010di\u0161t\u011bn\u00ed vody. Teprve v roce 1825 se d\u00e1nsk\u00e9mu fyzikovi Hansi Christianu Orstedovi poda\u0159ilo reakc\u00ed bezvod\u00e9ho chloridu hlinit\u00e9ho s drasl\u00edkem vyrobit ne\u010distou formu; pozd\u011bji t\u00e9ho\u017e roku se Friedrichu Wohlerovi poda\u0159ilo z\u00edskat \u010dist\u00fd kovov\u00fd hlin\u00edk.<\/p>\n
Hlin\u00edk je jedn\u00edm z nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00edch prvk\u016f na Zemi a p\u0159irozen\u011b se vyskytuje v hornin\u00e1ch a vegetaci na pevnin\u011b i ve vodn\u00edch ploch\u00e1ch. A\u010dkoli se hlin\u00edk v p\u0159\u00edrod\u011b nikdy nevyskytuje v \u010dist\u00e9m stavu, proto\u017ee se snadno spojuje s kysl\u00edkem a dal\u0161\u00edmi prvky za vzniku slou\u010denin, je tento kov velmi m\u011bkk\u00fd, tv\u00e1rn\u00fd, odoln\u00fd proti korozi, lehk\u00fd, elektricky vodiv\u00fd ne\u017eelezn\u00fd kov s jednou z nejvy\u0161\u0161\u00edch dostupn\u00fdch hodnot elektrick\u00e9 vodivosti pro v\u00fdrobu tenk\u00fdch plech\u016f a f\u00f3li\u00ed.<\/p>\n
Hlin\u00edk je d\u00edky sv\u00e9 n\u00edzk\u00e9 hmotnosti a tv\u00e1rnosti univerz\u00e1ln\u00edm konstruk\u010dn\u00edm materi\u00e1lem, proto\u017ee jej lze pou\u017e\u00edt jak v nosn\u00fdch, tak nenosn\u00fdch konstrukc\u00edch. D\u00edky sv\u00e9 tvarovatelnosti se nav\u00edc s oblibou pou\u017e\u00edv\u00e1 pro v\u00fdrobu letadel, karoseri\u00ed automobil\u016f, obklad\u016f a st\u0159e\u0161n\u00edch krytin, hrnc\u016f a p\u00e1nv\u00ed i spot\u0159ebn\u00edch v\u00fdrobk\u016f, jako jsou hrnce a p\u00e1nve. Hlin\u00edkov\u00e9 slitiny mohou tak\u00e9 poskytovat jedine\u010dn\u00e9 vlastnosti p\u0159izp\u016fsoben\u00e9 speci\u00e1ln\u011b pro ur\u010dit\u00e9 aplikace.<\/p>\n
P\u0159i v\u00fdrob\u011b hlin\u00edku se obvykle pou\u017e\u00edv\u00e1 Bayer\u016fv proces, p\u0159i n\u011bm\u017e se rozdrcen\u00e1 bauxitov\u00e1 hornina rozdrt\u00ed a post\u0159\u00edk\u00e1 vodou, \u010d\u00edm\u017e se odstran\u00ed \u010d\u00e1stice j\u00edlu a oxidu k\u0159emi\u010dit\u00e9ho, a pot\u00e9 se su\u0161\u00ed v peci a sm\u00edch\u00e1 s uhli\u010ditanem sodn\u00fdm a drcen\u00fdm v\u00e1pnem za vzniku oxidu hlinit\u00e9ho.<\/p>\n
Bauxit je hojn\u00e1 a cenov\u011b v\u00fdhodn\u00e1 surovina pro v\u00fdrobu hlin\u00edku, av\u0161ak proces taven\u00ed vy\u017eaduje energeticky n\u00e1ro\u010dn\u00e9 operace, p\u0159i nich\u017e se uvol\u0148uj\u00ed sklen\u00edkov\u00e9 plyny. Proto se v\u011bt\u0161ina sv\u011btov\u00fdch tav\u00edren nach\u00e1z\u00ed v zem\u00edch s dostatkem elektrick\u00e9 energie; mnoho tav\u00edren hlin\u00edku bylo tak\u00e9 postaveno na b\u0159ez\u00edch jezer, aby mohly zachycovat mo\u0159skou vodu a vyu\u017e\u00edvat ji ve sv\u00fdch procesech s c\u00edlem sn\u00ed\u017eit emise a z\u00e1rove\u0148 zv\u00fd\u0161it \u00fa\u010dinnost.<\/p>\n
Hlin\u00edk je st\u0159\u00edb\u0159it\u011b b\u00edl\u00fd kov ze 13. skupiny periodick\u00e9 tabulky prvk\u016f, kter\u00fd tvo\u0159\u00ed t\u0159etinu hmotnosti zemsk\u00e9 k\u016fry a je t\u0159et\u00edm nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00edm prvkem po kysl\u00edku a k\u0159em\u00edku. A\u010dkoli se hlin\u00edk v p\u0159\u00edrod\u011b vyskytuje jako kov v \u010dist\u00e9m stavu, jeho p\u0159\u00edtomnost \u010dasto tvo\u0159\u00ed miner\u00e1ly, jako je bauxit. Hlin\u00edk je jedn\u00edm ze t\u0159\u00ed celosv\u011btov\u011b nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00edch ne\u017eelezn\u00fdch kov\u016f a t\u0159et\u00edm nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00edm prvkem.<\/p>\n
Hlin\u00edk m\u00e1 mnoho \u017e\u00e1douc\u00edch vlastnost\u00ed a vyu\u017eit\u00ed v pr\u016fmyslu. Je t\u0159ikr\u00e1t leh\u010d\u00ed ne\u017e \u017eelezo, m\u00e1 zv\u00fd\u0161en\u00fd pom\u011br pevnosti a hmotnosti, p\u0159itom z\u016fst\u00e1v\u00e1 pru\u017en\u00fd, odoln\u00fd, korozivzdorn\u00fd, nemagnetizuje a m\u00e1 vynikaj\u00edc\u00ed elektrick\u00e9 vodiv\u00e9 vlastnosti - nemluv\u011b o tom, \u017ee je to jeden z nejlevn\u011bj\u0161\u00edch komer\u010dn\u011b dostupn\u00fdch kov\u016f! D\u00edky sv\u00e9 v\u0161estrannosti se hlin\u00edk pou\u017e\u00edv\u00e1 mimo jin\u00e9 na v\u00fdrobu n\u00e1dob, kuchy\u0148sk\u00e9ho n\u00e1dob\u00ed, n\u00e1pojov\u00fdch plechovek, trup\u016f letadel a karoseri\u00ed automobil\u016f.<\/p>\n
Kovov\u00fd hlin\u00edk m\u016f\u017ee p\u0159i vystaven\u00ed nep\u0159\u00edzniv\u00e9mu prost\u0159ed\u00ed korodovat, p\u0159i\u010dem\u017e vod\u00edkov\u00e9 ionty tento proces podporuj\u00ed reakc\u00ed s molekulami kysl\u00edku za vzniku oxidu hlinit\u00e9ho. Tato reakce je v\u0161ak vratn\u00e1 a povrch z\u016fst\u00e1v\u00e1 stabiln\u00ed, pokud koncentrace vod\u00edku v roztoku nep\u0159ekro\u010d\u00ed ur\u010ditou mezn\u00ed hodnotu; v tomto okam\u017eiku za\u010d\u00edn\u00e1 \u0161t\u011brbinov\u00e1 koroze a hydroxid hlinit\u00fd se vysr\u00e1\u017e\u00ed z roztoku a za\u010dne korodovat s\u00e1m od sebe - tzv. \u0161t\u011brbinov\u00e1 koroze.<\/p>\n
Hlin\u00edk m\u016f\u017ee podl\u00e9hat korozi v r\u016fzn\u00fdch podm\u00ednk\u00e1ch prost\u0159ed\u00ed, v\u010detn\u011b kysel\u00fdch, alkalick\u00fdch a chloridov\u00fdch roztok\u016f. Koroze obvykle za\u010d\u00edn\u00e1 rychle v trhlin\u00e1ch nebo prasklin\u00e1ch, ne\u017e se rozpust\u00ed v elektrolytu a vytvo\u0159\u00ed hydroxid hlinit\u00fd rozpustn\u00fd ve vod\u011b; tato forma koroze je obzvl\u00e1\u0161t\u011b \u010dast\u00e1 v mo\u0159sk\u00e9m prost\u0159ed\u00ed s vysokou koncentrac\u00ed chlorid\u016f.<\/p>\n
K rovnom\u011brn\u00e9 korozi doch\u00e1z\u00ed u v\u00fdrobk\u016f, kter\u00e9 jsou trvale vystaveny siln\u011b kysel\u00e9mu nebo z\u00e1sadit\u00e9mu prost\u0159ed\u00ed, nebo kdy\u017e je jejich povrch po\u0161kr\u00e1ban\u00fd nebo otlu\u010den\u00fd a z\u00e1kladn\u00ed materi\u00e1l je vystaven p\u016fsoben\u00ed elektrolyt\u016f; tento typ koroze \u010dasto vede k d\u016flkov\u00e9 korozi nebo exfolia\u010dn\u00ed korozi (mezizrnov\u00e1 forma koroze).<\/p>\n
Hlin\u00edk se hojn\u011b vyskytuje v cel\u00e9 zemsk\u00e9 k\u016f\u0159e, ale v p\u0159\u00edrod\u011b se nikdy nevyskytuje samostatn\u011b. M\u00edsto toho se vyskytuje v kombinaci s dal\u0161\u00edmi prvky bu\u010f jako s\u00edran draselno-hlinit\u00fd (KAl(SO4)212H2O), nebo jako bauxity; ty jsou \u010dervenohn\u011bd\u00e9 horniny obsahuj\u00edc\u00ed sm\u011bsi hydroxid\u016f a oxid\u016f hlin\u00edku, kter\u00e9 se t\u011b\u017e\u00ed ze zem\u011b a zpracov\u00e1vaj\u00ed Bayerov\u00fdm procesem, na\u010de\u017e se d\u00e1le rafinuj\u00ed na \u010dist\u00fd hlin\u00edk pro r\u016fzn\u00e9 \u00fa\u010dely.<\/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\/cs\/wp-json\/wp\/v2\/posts\/59","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aluminaceramics.net\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aluminaceramics.net\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aluminaceramics.net\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aluminaceramics.net\/cs\/wp-json\/wp\/v2\/comments?post=59"}],"version-history":[{"count":1,"href":"https:\/\/aluminaceramics.net\/cs\/wp-json\/wp\/v2\/posts\/59\/revisions"}],"predecessor-version":[{"id":60,"href":"https:\/\/aluminaceramics.net\/cs\/wp-json\/wp\/v2\/posts\/59\/revisions\/60"}],"wp:attachment":[{"href":"https:\/\/aluminaceramics.net\/cs\/wp-json\/wp\/v2\/media?parent=59"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aluminaceramics.net\/cs\/wp-json\/wp\/v2\/categories?post=59"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aluminaceramics.net\/cs\/wp-json\/wp\/v2\/tags?post=59"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}