Po v\u00edce ne\u017e dvaceti letech specifikov\u00e1n\u00ed mlec\u00edch m\u00e9di\u00ed pro v\u0161e od technick\u00e9 keramiky a\u017e po farmaceutick\u00e9 meziprodukty jsem se nau\u010dil, \u017ee zirkoniov\u00e9 kuli\u010dky jsou volbou, po kter\u00e9 s\u00e1hnete, kdy\u017e pr\u00e1ce vy\u017eaduje jak velk\u00fd mlec\u00ed v\u00fdkon, tak t\u00e9m\u011b\u0159 nulovou kontaminaci. zirkoniov\u00e9 kuli\u010dky stoj\u00ed v\u00edce ne\u017e oxid hlinit\u00fd nebo ocel, tak\u017ee se nedostanou do ka\u017ed\u00e9ho ml\u00fdna. Ve spr\u00e1vn\u00fdch aplikac\u00edch se v\u0161ak vyplat\u00ed d\u00edky rychlej\u0161\u00edmu zpracov\u00e1n\u00ed, del\u0161\u00ed \u017eivotnosti m\u00e9dia a \u010dist\u0161\u00edmu produktu. Vid\u011bl jsem, jak na n\u011b z\u00e1vody p\u0159e\u0161ly a u\u017e se nikdy neohl\u00e9dly zp\u011bt, a tak\u00e9 jsem vid\u011bl p\u0159\u00edpady, kdy dodate\u010dn\u00e9 n\u00e1klady neospravedl\u0148ovaly zisk. Rozd\u00edl obvykle spo\u010d\u00edv\u00e1 v pochopen\u00ed toho, co tyto kuli\u010dky skute\u010dn\u011b p\u0159in\u00e1\u0161ej\u00ed v provozu.<\/p>\n
Zirkoniov\u00e9 mlec\u00ed kuli\u010dky se vyr\u00e1b\u011bj\u00ed z oxidu zirkoni\u010dit\u00e9ho, t\u00e9m\u011b\u0159 v\u017edy stabilizovan\u00e9ho mal\u00fdm mno\u017estv\u00edm yttria (obvykle 3-5 mol % Y\u2082O\u2083), aby se materi\u00e1l udr\u017eel v hou\u017eevnat\u00e9 tetragon\u00e1ln\u00ed f\u00e1zi p\u0159i pokojov\u00e9 teplot\u011b. Proces za\u010d\u00edn\u00e1 vysoce \u010dist\u00fdm zirkonov\u00fdm pr\u00e1\u0161kem, kter\u00fd se rozemele, v\u00e1lcov\u00e1n\u00edm nebo lisov\u00e1n\u00edm se zformuje do koul\u00ed a pot\u00e9 se slinuje p\u0159i teplot\u00e1ch v\u00fdrazn\u011b vy\u0161\u0161\u00edch ne\u017e 1400 \u00b0C. V\u00fdsledkem je hust\u00e1, jemnozrnn\u00e1 koule s velmi n\u00edzkou p\u00f3rovitost\u00ed. V\u011bt\u0161ina komer\u010dn\u00edch druh\u016f pou\u017e\u00edvan\u00fdch k mlet\u00ed obsahuje 95 % nebo v\u00edce zirkonia, p\u0159i\u010dem\u017e se p\u0159\u00edsn\u011b kontroluje distribuce velikosti \u010d\u00e1stic a jejich kulatost. Velikosti se b\u011b\u017en\u011b pohybuj\u00ed od 0,1 mm do 30 mm nebo v\u00edce, v z\u00e1vislosti na tom, zda pou\u017e\u00edv\u00e1te kuli\u010dkov\u00fd ml\u00fdn pro velmi jemnou pr\u00e1ci nebo konven\u010dn\u00ed kulov\u00fd ml\u00fdn.<\/p>\n
V\u00fdraznou vlastnost\u00ed je hustota. S hustotou kolem 6,0 g\/cm\u00b3 jsou zirkoniov\u00e9 kuli\u010dky zhruba o 50 % hust\u0161\u00ed ne\u017e m\u00e9dia s vysok\u00fdm obsahem oxidu hlinit\u00e9ho. Tato dodate\u010dn\u00e1 hmotnost se p\u0159\u00edmo prom\u00edt\u00e1 do vy\u0161\u0161\u00ed energie n\u00e1razu p\u0159i mlet\u00ed, co\u017e znamen\u00e1 rychlej\u0161\u00ed redukci velikosti \u010d\u00e1stic, zejm\u00e9na v jemn\u011bj\u0161\u00edch rozm\u011brov\u00fdch \u0159ad\u00e1ch. Ve vysokoenergetick\u00fdch m\u00edchan\u00fdch ml\u00fdnech nebo ml\u00fdnech s kuli\u010dkami to m\u016f\u017ee zkr\u00e1tit dobu mlet\u00ed o 20-40 % ve srovn\u00e1n\u00ed s korundem za stejn\u00fdch podm\u00ednek. Rychlost opot\u0159eben\u00ed je tak\u00e9 mimo\u0159\u00e1dn\u011b n\u00edzk\u00e1 - \u010dasto \u0159\u00e1dov\u011b lep\u0161\u00ed ne\u017e u oxidu hlinit\u00e9ho p\u0159i mokr\u00e9m mlet\u00ed tvrd\u00fdch materi\u00e1l\u016f. Povrch z\u016fst\u00e1v\u00e1 dlouho hladk\u00fd, co\u017e pom\u00e1h\u00e1 udr\u017eovat st\u00e1l\u00fd mlec\u00ed v\u00fdkon a sni\u017euje mo\u017enost vzniku t\u0159\u00edsek, kter\u00e9 mohou do vs\u00e1zky vn\u00e9st hrub\u00e9 \u010d\u00e1stice.<\/p>\n
Chemick\u00e1 inertnost je dal\u0161\u00edm hlavn\u00edm d\u016fvodem, pro\u010d si rostliny vyb\u00edraj\u00ed zirkon. Tyto kuli\u010dky odol\u00e1vaj\u00ed p\u016fsoben\u00ed v\u011bt\u0161iny kyselin, louh\u016f a organick\u00fdch rozpou\u0161t\u011bdel a nevn\u00e1\u0161ej\u00ed prakticky \u017e\u00e1dn\u00e9 kovov\u00e9 ne\u010distoty. To m\u00e1 obrovsk\u00fd v\u00fdznam v elektronick\u00e9 keramice, kde \u017eelezo nebo jin\u00e9 kovy mohou zni\u010dit dielektrick\u00e9 vlastnosti, nebo p\u0159i mlet\u00ed ve farmaceutick\u00e9m a potravin\u00e1\u0159sk\u00e9m pr\u016fmyslu, kde jsou p\u0159\u00edsn\u00e9 po\u017eadavky na \u010distotu. Vid\u011bl jsem, jak se kuli\u010dka oxidu zirkoni\u010dit\u00e9ho pou\u017e\u00edv\u00e1 k mlet\u00ed vysoce \u010dist\u00fdch pr\u00e1\u0161k\u016f oxidu hlinit\u00e9ho pro pokro\u010dilou keramiku bez m\u011b\u0159iteln\u00e9ho p\u0159ib\u00edr\u00e1n\u00ed, co\u017e by p\u0159i pou\u017eit\u00ed ocelov\u00fdch nebo dokonce m\u00e9n\u011b kvalitn\u00edch keramick\u00fdch m\u00e9di\u00ed vy\u017eadovalo dal\u0161\u00ed \u010distic\u00ed kroky.<\/p>\n
V praxi se nejv\u011bt\u0161\u00ed p\u0159\u00ednosy projevuj\u00ed v aplikac\u00edch, kter\u00e9 vy\u017eaduj\u00ed jak jemnou velikost \u010d\u00e1stic, tak \u010dist\u00fd produkt. V\u00fdrobci pigment\u016f a barviv je pou\u017e\u00edvaj\u00ed k dosa\u017een\u00ed t\u011bsn\u00e9ho rozd\u011blen\u00ed velikosti \u010d\u00e1stic bez barevn\u00fdch zm\u011bn zp\u016fsoben\u00fdch kontaminac\u00ed. Farmaceutick\u00e9 spole\u010dnosti se na n\u011b spol\u00e9haj\u00ed p\u0159i mokr\u00e9m mlet\u00ed \u00fa\u010dinn\u00fdch l\u00e1tek, kde jsou nep\u0159\u00edpustn\u00e9 i stopov\u00e9 mno\u017estv\u00ed kov\u016f. V\u00fdrobci technick\u00e9 keramiky, kte\u0159\u00ed melou zirkon, karbid k\u0159em\u00edku nebo jin\u00e9 tvrd\u00e9 materi\u00e1ly, dosahuj\u00ed lep\u0161\u00edho v\u00fdkonu a men\u0161\u00edho opot\u0159eben\u00ed m\u00e9di\u00ed. V jednom z\u00e1vod\u011b, se kter\u00fdm jsem spolupracoval, se p\u0159echodem z kuli\u010dek oxidu hlinit\u00e9ho 95 % na kuli\u010dky ze stabilizovan\u00e9ho zirkonu yttria v kuli\u010dkov\u00e9m ml\u00fdn\u011b na pr\u00e1\u0161ek pro elektroniku sn\u00ed\u017eil mlec\u00ed cyklus t\u00e9m\u011b\u0159 o t\u0159etinu a prodlou\u017eil \u017eivotnost m\u00e9di\u00ed natolik, \u017ee se vy\u0161\u0161\u00ed po\u0159izovac\u00ed cena vr\u00e1tila b\u011bhem \u0161esti m\u011bs\u00edc\u016f.<\/p>\n
Samoz\u0159ejm\u011b, \u017ee zirkon nen\u00ed automatickou volbou pro ka\u017edou pr\u00e1ci. Vy\u0161\u0161\u00ed hustota, kter\u00e1 mu dod\u00e1v\u00e1 mlec\u00ed v\u00fdkon, znamen\u00e1 tak\u00e9 v\u011bt\u0161\u00ed opot\u0159eben\u00ed oblo\u017een\u00ed ml\u00fdn\u016f a m\u00edchadel, pokud pro n\u011bj za\u0159\u00edzen\u00ed nebylo navr\u017eeno. N\u011bkter\u00e9 star\u0161\u00ed kulov\u00e9 ml\u00fdny jednodu\u0161e nezvl\u00e1dnou dodate\u010dnou z\u00e1t\u011b\u017e bez \u00faprav. Dal\u0161\u00edm z\u0159ejm\u00fdm faktorem jsou n\u00e1klady - cena zirkonia je obvykle t\u0159ikr\u00e1t a\u017e p\u011btkr\u00e1t vy\u0161\u0161\u00ed ne\u017e cena kvalitn\u00edho m\u00e9dia z oxidu hlinit\u00e9ho v p\u0159epo\u010dtu na hmotnost. To m\u00e1 smysl pouze tehdy, kdy\u017e hodnota rychlej\u0161\u00ed v\u00fdroby, sn\u00ed\u017een\u00ed kontaminace nebo del\u0161\u00ed \u017eivotnosti m\u00e9dia p\u0159ev\u00e1\u017e\u00ed po\u010d\u00e1te\u010dn\u00ed n\u00e1klady. P\u0159i hrub\u00e9m mlet\u00ed levn\u00fdch miner\u00e1l\u016f nebo p\u0159i mlet\u00ed za sucha, kde je d\u016fle\u017eit\u011bj\u0161\u00ed r\u00e1zov\u00e1 hou\u017eevnatost ne\u017e odolnost proti opot\u0159eben\u00ed, z\u016fst\u00e1v\u00e1 ocel nebo oxid hlinit\u00fd \u010dasto ekonomicky v\u00fdhodn\u011bj\u0161\u00ed variantou.<\/p>\n
Z\u00e1le\u017e\u00ed na detailech v\u00fdb\u011bru a provozu. Nejb\u011b\u017en\u011bj\u0161\u00ed a obecn\u011b nejtvrd\u0161\u00ed pro brou\u0161en\u00ed je zirkon stabilizovan\u00fd yttria, ale pro ur\u010dit\u00e9 vysokoteplotn\u00ed nebo specifick\u00e9 chemick\u00e9 prost\u0159ed\u00ed existuj\u00ed i druhy stabilizovan\u00e9 ceriem. Velikost kuli\u010dek a pom\u011br n\u00e1pln\u011b se st\u00e1le \u0159\u00edd\u00ed obvykl\u00fdmi pravidly - sm\u011bs velikost\u00ed \u010dasto funguje nejl\u00e9pe - ale proto\u017ee je m\u00e9dium hust\u0161\u00ed, m\u016f\u017ee b\u00fdt nutn\u00e9 upravit hmotnost n\u00e1pln\u011b nebo rychlost ml\u00fdna, aby nedo\u0161lo k p\u0159et\u00ed\u017een\u00ed. Vyplat\u00ed se pravideln\u00e1 kontrola na p\u0159\u00edtomnost t\u0159\u00edsek nebo prasklin; i hou\u017eevnat\u00fd zirkon m\u016f\u017ee prasknout, pokud se do ml\u00fdna dostane ciz\u00ed kov. Dobr\u00e1 p\u00e9\u010de a spr\u00e1vn\u00e9 postupy nakl\u00e1d\u00e1n\u00ed se vyplat\u00ed.<\/p>\n
Z toho, co jsem vid\u011bl v r\u016fzn\u00fdch pr\u016fmyslov\u00fdch odv\u011btv\u00edch, vypl\u00fdv\u00e1, \u017ee zirkonov\u00e9 kuli\u010dky dosahuj\u00ed nejlep\u0161\u00edch v\u00fdsledk\u016f, pokud se ji\u017e v procesu oce\u0148uje konzistence a \u010distota. Nevy\u0159e\u0161\u00ed z\u00e1zra\u010dn\u011b \u0161patnou konstrukci ml\u00fdna nebo \u0161patnou chemii kalu, ale kdy\u017e je v\u0161e ostatn\u00ed p\u0159im\u011b\u0159en\u011b optimalizov\u00e1no, nen\u00e1padn\u011b zlep\u0161\u00ed v\u00fdkon i kvalitu produktu. Z\u00e1vody, kter\u00e9 sleduj\u00ed dobu mlet\u00ed, spot\u0159ebu m\u00e9dia a \u00farove\u0148 zne\u010di\u0161t\u011bn\u00ed p\u0159ed a po v\u00fdm\u011bn\u011b, obvykle nejl\u00e9pe rozhodnou, zda se jim investice vyplat\u00ed pro jejich konkr\u00e9tn\u00ed podm\u00ednky.<\/p>\n
Nakonec zirkonov\u00e9 brusn\u00e9 kuli\u010dky z\u016fst\u00e1vaj\u00ed prvot\u0159\u00eddn\u00edm, ale praktick\u00fdm n\u00e1strojem. Vynikaj\u00ed tam, kde se spojuje vysok\u00e1 hustota, n\u00edzk\u00e9 opot\u0159eben\u00ed a minim\u00e1ln\u00ed zne\u010di\u0161t\u011bn\u00ed, a \u0159e\u0161\u00ed tak skute\u010dn\u00e9 v\u00fdrobn\u00ed probl\u00e9my. Pokud tyto faktory odpov\u00eddaj\u00ed va\u0161im ekonomick\u00fdm mo\u017enostem a vybaven\u00ed, z\u00edsk\u00e1vaj\u00ed sv\u00e9 m\u00edsto. Kdy\u017e tomu tak nen\u00ed, nen\u00ed ostuda z\u016fstat u korundu nebo oceli. Dovednost spo\u010d\u00edv\u00e1 v tom, \u017ee v\u00edte, v jak\u00e9 situaci se nach\u00e1z\u00edte.<\/p>","protected":false},"excerpt":{"rendered":"
After more than twenty years specifying grinding media for everything from technical ceramics to pharmaceutical intermediates, I\u2019ve learned that zirconia ball are the choice you reach for when the job demands both serious grinding power and almost zero contamination. zirconium oxide ball cost more than alumina or steel, so they don\u2019t go into every mill. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[5],"tags":[],"class_list":{"0":"post-309","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-zirconia-grinding-media","7":"czr-hentry"},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/posts\/309"}],"collection":[{"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/comments?post=309"}],"version-history":[{"count":1,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/posts\/309\/revisions"}],"predecessor-version":[{"id":310,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/posts\/309\/revisions\/310"}],"wp:attachment":[{"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/media?parent=309"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/categories?post=309"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/tags?post=309"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}