Lead ore muaj cov qauv zoo nkauj. Nws raug ua tiav rau lub sijhawm ntev thiab tom qab melting polymetallic ores, txhuas tau txais. Kev txiav txim los ntawm kev tshawb fawb archaeological, txoj hauv kev rau rho tawm cov hlau lead thiab cov hlau nws tus kheej tau paub txij li lub sijhawm qub. Qhov kev tshawb pom qub tshaj plaws tau pom nyob rau hauv 6,000 xyoo faus. Cov duab ntawm cov khoom qub yog ib tug pas nrig, nws kov yog ntoo, tab sis muaj ib lub taub hau.
khoom siv lead ua
Ntshiab lead yog paub, tab sis tsis tshua muaj neeg. Cov xim xiav-grey uas muaj lub ci xim hlau ci thaum txiav thiab oxidizes sai heev thaum raug huab cua. Nws yog tus naj npawb 82 ntawm lub rooj tshuaj. Mos, tuaj yeem khawb nrog tus ntsia hlau thiab tawm ntawm cov xim dub rau ntawm daim ntawv. Lub ntiajteb txawj nqus tshwj xeeb ntawm cov hlau yog 11.40. Nws melts ntawm 325 ° C thiab crystallizes thaum txias qeeb. Nws muaj zog me ntsis thiab tsis tuaj yeem rub mus rau hauv ib lub xaim, tab sis txawm li cas los xij nws yog ib qho yooj yimdov los yog nias rau hauv cov ntawv nyias.
Nws cov khoom muaj feem cuam tshuam los ntawm qhov muaj me me ntawm impurities. Lead yog yooj yim heev muab rho tawm los ntawm cov tebchaw thiab yog soluble nyob rau hauv dilute nitric acid. Nws tsim ntau qhov sib txuas ntawm kev lag luam tseem ceeb. Piv txwv li, lead litharge thiab liab lead yog oxides, dawb lead yog ib qho yooj yim carbonate.
Nyob ntawm cov hlau lead
Feem ntau cuam tshuam nrog zinc lossis silver ores yog galena. Cov hmoov txhuas tau los ntawm yav tas los yog hu ua "nyuaj", thiab los ntawm cov nyiaj tsis muaj hlau - "mos". Nyob rau hauv lub Upper qhov chaw ntawm galena deposits yog oxidized rau ntau oxys alts. Yog li, cov hlau lead tseem ceeb yog: cerussite, anglesite, pyromorphite, mimetite, vanadinite, crocoite thiab wulfenite.
Raws li txoj cai, galena nyob hauv cov leeg sib sib zog nqus uas tsis tau oxidized. Thaum cov hlab ntsha yog oxidized thiab weathered, anglesites tshwm raws li cov khoom hloov pauv. Cov ntxhia no tsis ruaj khov piv rau cerussite thiab hloov mus rau tom kawg thaum raug cov dej carbonized. Qhov twg cov kev daws teeb meem hauv thaj tsam oxidation hla phosphate pob zeb, pyromorphite tsim. Qhov twg galena muaj nyiaj, nyiaj ntxhia yog tsim los ntawm oxidation.
Qee cov nyiaj tseem ceeb tshaj plaws hauv ntiaj teb tau tsim los ntawm txoj kev no. Ntau cov minerals tshwm sim ua ke nrog galena nyob rau hauv cov hlau lead ore veins, ib qho ntawm feem ntauIb tug ntawm lawv yog sphalerite. Qhov tseem ceeb tshaj plaws ntawm lwm cov minerals uas txuam nrog yog calcite, dolomite, siderite, pyrite, chalcopyrite, barite thiab fluorite.
Ntsuab thiab siv tshuab
Muaj 3 txheej txheem tseem ceeb hauv kev ua cov hmoov txhuas-zinc: crushing, sib tsoo thiab tau txais txiaj ntsig. Txhawm rau tsim cov hmoov txhuas, piv txwv li los ntawm galena lossis cerussite, cov ore yog thawj feem roasted los yog calcined thiab ces smelted nyob rau hauv reverberation los yog blast furnaces. Feem ntau cov hlau lead muaj nyiaj. Cov hlau no tau txais los ntawm cupping lossis lwm txoj hauv kev. Sphalerite feem ntau cuam tshuam nrog galena, tab sis cov smelters tsis tshua siv cov hlau lead uas muaj ntau tshaj 10 feem pua zinc vim tias nws muaj qhov ua rau nyuaj rau smelting. Nyob rau hauv tas li ntawd, mus rau lub mechanical sib cais ntawm ob minerals (enrichment). Qee zaum kev poob tseem ceeb ntawm cov hlau lead thiab zinc tshwm sim thaum lub sijhawm ua haujlwm no.
Thaum cov hmoov txhuas tau rhuab rau ntawm charcoal ib leeg, lawv tsim cov xim daj daj daj. Thaum rhuab nrog poov tshuaj iodide thiab sulfur, lawv tsim ib tug ci daj txheej. Roasting nrog sodium carbonate thiab charcoal tsim cov hlau lead, uas zoo nkaus li cov hlau lead grey pob uas ci thaum kub tab sis npub thaum txias. Yog hais tias antimony yog txuam nrog galena, cov ore feem ntau smelted tsis kho, ncaj qha mus tsim antimonial lead.
Applications
Metallic lead yog siv rau hauv daim ntawv, cov kav dej, thiab lwm yam. Nws yog siv raumanufacturing scale, mos txwv thiab txhaj tshuaj. Nws tseem yog ib feem ntawm ntau yam alloys xws li solder (lead thiab tin), hard hlau (lead thiab antimony) thiab low-melting alloys (lead, bismuth thiab tin). Ib qho me me ntawm cov hlau lead yog siv rau hauv daim ntawv ntawm ib qho yooj yim carbonate, uas yog hu ua dawb lead thiab muaj txiaj ntsig zoo li xim xim. Oxides ntawm txhuas, litharge thiab liab lead yog siv nyob rau hauv kev tsim cov iav ntawm zoo heev zoo, nyob rau hauv glazes rau av nplaum khoom thiab nyob rau hauv daim ntawv ntawm cov xim pigments. Lead chromates yog siv los ua xim daj thiab xim liab. Lead acetate, hu ua lead qab zib, yog qhov tseem ceeb hauv kev lag luam ntau yam.
Vim tias muaj cov hmoov txhuas thiab zinc, cov zinc ore muaj peev xwm ua tau zoo heev. Nws yog dav siv nyob rau hauv hluav taws xob engineering, mechanical engineering, tub rog kev lag luam, metallurgy, lub teeb kev lag luam, tshuaj thiab tshuaj industries. Tsis tas li ntawd, zinc hlau muaj ntau yam kev siv hauv kev lag luam nuclear thiab roj.
Ore deposits
Lead deposits tau ua tiav nyob rau hauv peb chav kawm sib txawv, raws li lawv tau mined: txhuas, txhuas thiab zinc, txhuas thiab nyiaj. Nyob rau hauv xyoo tas los no, cov hlau lead silver ores yog qhov loj tshaj plaws ntawm cov hlau. Qhov tseem ceeb ntawm lwm tus yog thaj tsam sab hnub tuaj ntawm Missouri.
Galena pom ob qho tib si hauv txheej thiab hauv cov leeg. Metasomatic lead thiab zinc veins tshwm sim nyob rau hauv kev sib cuag metamorphic deposits nyob rau hauv limestone. Cov no yog Derbyshire, Flintshire, Cumberland hauv Askiv; Muag hauvSweden; Reibl thiab Blayberg (Carinthia), Leadville (Colorado), Utah, Wisconsin, thiab lwm yam.
Hydrothermal primordial veins yog lwm txoj hauv kev uas galena tshwm sim. Qhov no siv rau sphalerite, pyrite, quartz thiab barite: deposits ntawm Cardigan, Miner, Isle of Man, Cornwall, Derbyshire, Aspen thiab Rico (Colorado), Broken Hill (New South Wales) thiab Freiberg (Saxony). Tebchaws Meskas ib zaug muab txog 90% ntawm lub ntiaj teb cov hlau lead. Ntau tsawg tau tso tawm tsis ntev los no. Lub teb chaws ntawm Spain, Australia, Lub teb chaws Yelemees, Poland thiab Mexico kuj tsim cov hlau lead ntau. Ua raws li UK, Russia, Fabkis, Canada, Greece thiab Ltalis.
Kev kwv yees ntawm cov peev txheej muaj peev xwm khaws cia hauv Russia tau muab tso rau hauv qhov chaw thib ob hauv ntiaj teb, tab sis hais txog kev tsim khoom, lub tebchaws tsuas yog thib xya. Qhov loj tshaj plaws deposits ntawm txhuas ores nyob rau hauv ib ncig ntawm Eastern Siberia, muaj 68 ntawm lawv nyob rau hauv tag nrho.
