Hlau thiab alloys tau nkag mus rau peb lub neej zoo heev uas qee zaum peb tsis xav txog lawv. Thaum ntxov li 4-3 txhiab xyoo BC, thawj tus neeg paub txog tus txiv neej nrog nuggets tau tshwm sim. Ntau lub sij hawm tau dhau mus txij thaum ntawd los, thiab txhua xyoo kev ua hlau tsuas yog txhim kho.
Zinc tau ua lub luag haujlwm loj hauv qhov no. Alloys raws li nws yog siv nyob rau hauv ntau industries. Hauv kab lus no, peb yuav saib cov zinc alloys thiab lawv lub luag haujlwm hauv peb lub neej.
Kev hloov pauv hlau
Zinc paub tias yog xim dawb-dawb nkig hloov hlau. Nws yog mined los ntawm semi-metallic ores. Cov txheej txheem kom tau txais cov zinc ntshiab yog qhov nyuaj heev thiab siv sijhawm ntev. Ua ntej ntawm tag nrho cov, ore muaj los ntawm 1-4% zinc yog enriched los ntawm xaiv flotation. Los ntawm cov txheej txheem no concentrates (55% Zn) tau txais. Tom ntej no, koj yuav tsum tau txais zinc oxide. Rau qhov no, lub resulting concentrates yog calcined nyob rau hauv furnaces nyob rau hauv ib tug fluidized txaj. Tsuas yog los ntawmzinc oxide, koj tuaj yeem tau txais cov hlau no hauv nws daim ntawv ntshiab, thiab muaj ob txoj hauv kev ua qhov no.
Tau txais zinc
Thawj yog electrolytic, raws li kev kho mob ntawm zinc oxide nrog sulfuric acid. Raws li qhov tshwm sim ntawm cov tshuaj tiv thaiv no, cov tshuaj sulfate yog tsim, uas yog purified los ntawm impurities thiab raug rau electrolysis. Zinc yog tso rau ntawm txhuas cathodes, uas yog tom qab ntawd yaj hauv induction furnaces. Lub purity ntawm zinc yog li tau txais yog li ntawm 99.95%.
Txoj kev thib ob, qhov qub tshaj plaws, yog distillation. Cov concentrates yog rhuab mus rau qhov kub siab heev (kwv yees li 1000 ° C), zinc vapors raug tso tawm, uas, los ntawm condensation, nyob rau hauv av nplaum hlab ntsha. Tab sis txoj kev no tsis muab xws li purity li thawj. Qhov tshwm sim vapor muaj txog 3% ntawm ntau yam impurities, suav nrog cov khoom tseem ceeb xws li cadmium. Yog li ntawd, Zn yog ntxiv purified los ntawm kev cais. Ntawm qhov kub ntawm 500 ° C nws tiv thaiv qee lub sijhawm thiab purity ntawm 98% tau txais. Rau kev tsim cov hlau txuas ntxiv, qhov no yog qhov txaus, vim tias tom qab ntawd zinc tseem alloyed nrog tib lub ntsiab lus. Yog tias qhov no tsis txaus, kev kho yog siv thiab zinc tau txais nrog purity ntawm 99.995%. Yog li, ob txoj kev tso cai kom tau txais zinc purity siab.
Ib khub tsis sib xws ntawm hlau
Feem ntau, txhuas muaj nyob rau hauv zinc alloys raws li impurity. Nyob rau hauv qhov xwm txheej, no inseparable khub ntawm hlau yog pom heev heev. Tab sis qhov tseeb, cov ntsiab lus txhuas siab hauv zinc alloy degrades nws lub cev, tsim kom muaj kev sib haum xeeb rau intergranular corrosion yog tias nws yog.cov ntsiab lus siab tshaj 0.007%. Lead thiab zinc feem ntau pom ua ke hauv tin bronzes thiab tooj dag.
Yog tias peb tham txog eutectic ntawm ob lub ntsiab lus no, nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias mus txog qhov kub ntawm 800 ° C lawv tsis sib tov thiab sawv cev rau ob lub kua sib txawv. Thaum lub sij hawm txias ceev, ib qho kev faib tawm ntawm Pb tshwm sim nyob rau hauv daim ntawv ntawm rounded inclusions nyob rau hauv lub grain ciam teb. Zinc-lead alloy yog siv los ua cov ntawv luam tawm vim tias nws dissolves sai heev hauv cov kua qaub. Feem ntau, txhuas impurities raug tshem tawm los ntawm zinc siv txoj kev distillation.
tooj liab zinc alloy
Brass yog ib qho alloy paub txawm tias ua ntej peb lub sijhawm. Lub sijhawm ntawd, zinc tseem tsis tau pom, tab sis cov ore tau siv dav. Yav dhau los, tooj dag tau txais los ntawm alloying smithsonite (zinc ore) thiab tooj liab. Nws tsuas yog nyob rau hauv lub xyoo pua 18th uas cov hlau no yog thawj zaug siv hlau zinc.
Nyob rau hauv peb lub sijhawm, muaj ntau ntau yam ntawm tooj dag: ib theem thiab ob-theem. Cov qub muaj li 35% zinc, thaum tom kawg muaj 50% thiab 4% txhuas. Ib-theem brasses yog ductile heev, thaum lub thib ob ntau yam yog yus muaj los ntawm brittleness thiab hardness. Tau txiav txim siab lub xeev daim duab ntawm ob lub ntsiab lus no, peb tuaj yeem xaus tias lawv tsim cov theem hluav taws xob: β, γ, ε. Ib qho nthuav ntau yam ntawm tooj dag yog tompak. Nws tsuas muaj txog li 10% zinc thiab vim qhov no nws muaj ductility siab heev. Tompak tau ntse siv rau steel cladding thiab bimetal ntau lawm. ua ntej nwssiv los ua npib thiab imitation kub.
Zinc thiab steel
Yuav luag txhua lub tsev koj tuaj yeem pom cov khoom siv galvanized: thoob, lauj kaub, dej kub npau npau, thiab lwm yam. Tag nrho cov ntawm lawv muaj kev ntseeg siab tiv thaiv los ntawm xeb ua tsaug rau zinc. Figuratively hais lus, tau kawg, steel yog coated nrog no hlau, thiab logically, peb tsis tau tham txog ib tug alloy. Ntawm qhov tod tes, paub tias yuav ua li cas galvanizing tshwm sim, qhov sib txawv tuaj yeem sib cav. Qhov tseeb yog tias zinc melts ntawm qhov kub qis heev (kwv yees li 400 ° C), thiab thaum nws nkag mus rau hauv cov hlau hauv cov kua hauv lub xeev, nws diffuses rau hauv nws.
Cov atoms ntawm ob yam khoom yog nruj heev ua ke, ua ib tug hlau-zinc alloy. Vim li no, peb tuaj yeem hais tias Zn tsis yog "nteg" ntawm cov khoom, tab sis "kos" hauv nws. Qhov no tuaj yeem pom nyob rau hauv ib qho xwm txheej hauv tsev. Piv txwv li, ib qho khawb tshwm rau ntawm lub thoob galvanized. Puas yog nws pib xeb ntawm no? Cov lus teb yog unequivocal - tsis yog. Qhov no yog vim hais tias thaum ya raws nkag mus, zinc tebchaw pib tawg, tab sis tib lub sij hawm lawv tsim ib co kev tiv thaiv rau hlau. Yog li, feem ntau, xws li zinc alloys yog tsim los tiv thaiv cov khoom los ntawm corrosion. Tau kawg, lwm yam tshuaj, xws li chromium lossis npib tsib xee, kuj tuaj yeem siv rau lub hom phiaj no, tab sis tus nqi ntawm cov khoom no yuav ntau zaus dua.
Tin thiab zinc
Cov alloy no tsis muaj npe tsawg dua li lwm tus uas peb tau tshuaj xyuas lawm. Xyoo 1917-1918 hauv Bulgaria, nws tau dav siv los ua cov hlab ntsha tshwj xeeb uas tuav cov kua dej sov rau lub sijhawm ntev.(analogues ntawm niaj hnub thermoses). Niaj hnub no, zinc-tin alloy yog dav siv hauv xov tooj cua thiab hluav taws xob kev lag luam. Qhov no yog vim lub fact tias cov muaj pes tsawg leeg nrog ib tug Zn ntsiab lus ntawm 20% yog soldered zoo heev, thiab cov deposit polishing yog khaws cia rau lub sij hawm ntev.
Tau kawg, raws li cov txheej txheem tiv thaiv corrosion, cov hlau no kuj siv tau. Nws cov yam ntxwv zoo ib yam li cadmium txheej, tab sis tib lub sijhawm tsis tshua kim.
Khoom ntawm zinc alloys
Tau kawg, txhua qhov sib xyaw nrog cov hlau no txawv ntawm ib leeg hauv nws qhov feem pua. Feem ntau, zinc alloys muaj zoo casting thiab mechanical zog. Thawj thiab foremost yog corrosion kuj. Feem ntau ntawm tag nrho cov, nws manifests nws tus kheej nyob rau hauv ib tug huab cua qhuav huv si. Muaj peev xwm tshwm sim ntawm corrosion tuaj yeem pom hauv cov nroog muaj. Qhov no yog vim muaj hydrochloric acid vapors, chlorine thiab sulfur oxides nyob rau hauv cov huab cua, uas, condensing nrog noo noo, ua rau nws nyuaj rau tsim ib tug tiv thaiv zaj duab xis. Copper-tin-zinc yog ib qho alloy uas muaj kev tiv thaiv siab. Nws yog qhov muaj pes tsawg leeg uas tsis tshua muaj kev cuam tshuam rau corrosion, tshwj xeeb tshaj yog nyob rau hauv ib qho chaw ua lag luam. Yog tias peb tham txog cov khoom pov thawj ntawm zinc, ces, ntawm chav kawm, lawv nyob ntawm cov ntsiab lus alloying hauv nws cov alloys.
Yog li, piv txwv li, txhuas ua rau lawv cov qauv zoo sib xws, nplua-grained, ennobles nws, txo qhov tsis zoo ntawm cov hlau. Lwm qhov tseem ceeb alloying keeb yog tooj liab. Nws ua kom muaj zog thiab txo qisintercrystalline corrosion kuj. Cov tooj liab-zinc alloy muaj lub zog muaj zog, tab sis tib lub sijhawm qee qhov poob nws cov khoom pov thawj.
Teb daim ntawv thov ntawm zinc thiab nws cov alloys
Qhov tseeb, qhov chaw ua los ntawm zinc alloys muaj ntau heev hauv peb lub sijhawm. Txawm hais tias cov yas hloov pauv cov khoom siv hlau, qee zaum lawv tsis tuaj yeem muab faib nrog. Piv txwv li, kev lag luam tsheb yog kev lag luam uas tsis tuaj yeem ua yam tsis muaj zinc alloys. Lim, sups, carburetor thiab roj twj tso kua mis vaj tse, log npog, mufflers - tag nrho cov no thiab ntau ntxiv yog tsim los siv cov tebchaw ntawm cov tshuaj no.
Vim qhov tseeb tias zinc alloys muaj cov khoom zoo casting, qhov nyuaj ntawm ntau cov duab raug nrum los ntawm lawv nrog qhov tsawg kawg nkaus phab ntsa thickness. Kev tsim kho yog lwm qhov chaw uas cov alloys no tseem ceeb. Rolled zinc yog siv rau ru tsev, kav dej thiab gutters. Txawm hais tias muaj qhov xav tau los txo qhov kev tsim cov zinc alloys, nws tsis tuaj yeem tso tseg lawv cov khoom vim qhov txheeb ze pheej yig thiab cov khoom siv tshuab ntawm cov khoom.
