Chalk yog pob zeb dawb sedimentary. Nws yog insoluble hauv dej thiab yog cov organic keeb kwm. Los ntawm tsab xov xwm peb kawm qhov twg chalk siv, lub cev thiab tshuaj lom neeg ntawm lub pob zeb no.
Kev Kawm
90 lab xyoo dhau los nyob rau sab qaum teb Europe, cov av tau sau nyob rau thaj tsam qis ntawm hiav txwv loj. Protozoa (foraminifera) nyob rau hauv cov dej khib nyiab. Lawv cov khoom suav nrog calcite muab rho tawm los ntawm dej. Cov Cretaceous pawg ntawm stratigraphic European faib tau tshwm sim thaum lub sij hawm ntawm tib lub npe. Nws tsim cov Cliffs Dawb hauv Kent thiab cov nqes hav hauv lwm qhov ntawm Strait of Dover. Nws yog cov seem uas tau los ua lub hauv paus ntawm chalk. Txawm li cas los xij, lub pob zeb feem ntau yog tsim ntawm algae thiab cov sib xyaw ua kom zoo. Yog li, cov kws tshawb fawb xaus lus tias qhov pom ntawm chalk yog qhov zoo ntawm cov nroj tsuag.
Txiv kab ntxwv
Cov seem ntawm cov mollusks uas sau hauv qab cov sediments hloov mus ua chalk. Cov tsiaj muaj:
- About 10% skeletal khib nyiab. Ntawm lawv tsis yog tsuas yog ib feem ntawm qhov yooj yim tshaj plaws, tab sis kujtsiaj txhu ntau.
- About 10% ntawm foraminifer plhaub.
- Txog 40% tawg ntawm calcareous algae formations
- Txog 50% crystalline zoo calcite. Nws qhov loj me me heev uas nws yuav luag tsis tuaj yeem tsim kom muaj lub cev nqaij daim tawv ntawm cov khoom uas ua rau nws.
- Txog li 3% cov zaub mov tsis txaus. Lawv feem ntau sawv cev los ntawm silicates. Insoluble minerals yog ib yam ntawm geological khib nyiab (fragments ntawm ntau yam pob zeb thiab xuab zeb), uas yog coj mus rau hauv lub chalk deposits los ntawm tam sim no thiab cua.
Plhaub ntawm mollusks, concretions ntawm lwm yam minerals, skeletons ntawm coelenterates tsis tshua muaj pom nyob rau hauv lub pob zeb.
Kev piav qhia ntawm lub cev khoom ntawm chalk - lub zog
Kev tshawb fawb ntawm cov tshuaj tau ua los ntawm ntau tus kws tshawb fawb. Nyob rau hauv chav kawm ntawm engineering thiab geological kev ua ub no, nws tau qhia tias nws yog ib lub pob zeb ib nrab pob zeb. Nws lub zog yog feem ntau txiav txim siab los ntawm noo noo. Hauv huab cua qhuav, qhov kawg compressive zog txawv ntawm 1000 txog 45,000 kN / m2. Lub elasticity modulus ntawm pob zeb qhuav yog los ntawm 3 txhiab MPa (rau lub xeev xoob) mus rau 10 txhiab MPa (rau lub xeev ntom). Tus nqi ntawm lub kaum sab xis ntawm kev sib txhuam sab hauv yog 24-30 degrees, nrog rau txhua qhov kev sib txhuam, qhov adhesion nce mus txog 700-800 kN / m 2.
Humidity
Thaum raug dej, lub cev lub cev ntawm chalk pib hloov. Tshwj xeeb, nws lub zog yog txo. Kev hloov pauv tau tshwm sim ntawm 1-2% av noo. Ntawm 25-35%, lub zog compressive nce 2-3 zaug. Nrog rau qhov no, lwm yam khoom siv lub cev ntawm chalk tshwm. Lub pob zeb ua yas. Qhov no yogmanifestation ho complicates tus txheej txheem ntawm kev ua cov khoom. Thaum lub sij hawm no, chalk pib lo rau lub tshuab ntsiab (excavator thoob, conveyor siv, feeder, tsheb lub cev). Feem ntau cov khoom ntawm lub cev ntawm chalk (viscosity thiab plasticity) tsis tso cai mining los ntawm qis dua qab ntug, txawm hais tias ntawm no nws suav hais tias yog qhov zoo.
Frost resistance
Tom qab khov-thawing, cov av nplaum tawg mus rau hauv cov khoom ntawm 1-2 hli. Qee zaum, qhov no yog ib qho khoom muaj txiaj ntsig zoo ntawm cov tsiaj. Piv txwv li, thaum nws yog siv los ua ameliorant thaum lub sij hawm av deoxidation, nws tsis yog yuav tsum tau zom cov khoom rau 0.25 hli. Crushed pob zeb txog li 10 mm tuaj yeem nkag mus rau hauv av. Thaum khov-thawing nrog plowing cov av, daim yog puas los ntawm lawv tus kheej. Yog li, qhov kev txiav txim siab nruab nrab tau khaws cia ntev.
Chalk zog: chemistry
Lub pob zeb feem ntau suav nrog carbonate thiab tsis yog carbonate. Thawj yog soluble hauv acetic thiab hydrochloric acids. Cov uas tsis yog-carbonate muaj hlau oxides, quartz xuab zeb, marls, av nplaum, thiab lwm yam. Ib txhia ntawm lawv yog insoluble nyob rau hauv cov acids. Cov carbonate feem muaj 98-99% calcium carbonate. Crystalline particles ntawm magnesian calcite, siderite thiab dolomite yog tsim los ntawm magnesium carbonates, uas muaj nyob rau hauv chalk nyob rau hauv me me. Cov muaj pes tsawg leeg thiab cov khoom ntawm pob zeb ua raws li kev faib tawm.
Kev txheeb xyuas cov nyiaj tso cia zoo
Thawj zaug nws tau ntseeg tias cov khoom siv hluav taws xob thiab tshuaj lom neeg ntawm chalkyog tib yam thoob plaws hauv daim teb. Txawm li cas los xij, hauv kev xyaum, thaum lub sijhawm ua haujlwm ntev hauv cheeb tsam, tshwj xeeb tshaj yog tom qab kev hloov pauv ntawm cov mining thiab kev lag luam rau kev tsim cov khoom zoo dua, qhov sib txawv ntawm cov yam ntxwv no tau tshwm sim. Yog li ntawd, geological thiab technological mapping yog nqa tawm nyob rau hauv ib co teb. Cov kws tshawb fawb, kawm txog cov khoom siv tshuaj lom neeg ntawm chalk thiab nws cov yam ntxwv ntawm cov khoom siv sib txawv ntawm qhov sib txawv ntawm qhov tso nyiaj, xaiv thaj chaw ntawm cov pob zeb zoo.
Industrial development
Cov nyiaj loj ntawm chalk muaj nyob hauv thaj tsam Belgorod thiab Voronezh. Cov khoom tsis zoo yog tam sim no nyob rau hauv Znamenskaya, Zaslonovskaya, Valuyskaya thiab lwm yam deposits. Cov kev tso nyiaj no qhia tus nqi qis ntawm CaCO3 (tsis ntau tshaj 87%). Tsis tas li ntawd, ntau yam impurities muaj nyob rau hauv pob zeb. Yog li ntawd, cov khoom lag luam zoo tsis tuaj yeem tau txais ntawm cov deposits no yam tsis muaj kev sib sib zog nqus. Lub cev muaj zog ntawm chalk ntawm xws li deposits ua rau nws muaj peev xwm siv tau nyob rau hauv kev tsim cov txiv qaub, nrog rau hauv av reclamation ntsuas los deoxidize av. Lub Voronezh deposits yog ntaus nqi rau lub hnub nyoog Turonian-Coniacian. Zoo dua chalk yog mined ntawm no. Cov khoom thiab daim ntawv thov ntawm cov pob zeb tau txais los ntawm cov deposits no tau kawm ntev. Cov khoom lag luam mined hauv cheeb tsam Voronezh muaj cov ntsiab lus siab ntawm CaCO3 (txog 98.5%). Qhov feem ntawm cov tsis-carbonate impurities yog tsawg dua 2%. Mining ntawm cov deposits, txawm li cas los, yog hampered los ntawm lub cev khoom ntawm lub chalk. Tshwj xeeb, nwsdej saturation siab. Qhov kev faib ua feem ntawm cov dej noo hauv cov pob zeb yog li 32%.
Promising deposits
Ntawm cov kev tso nyiaj loj, nws tsim nyog sau Rossoshanskoye, Krupnennikovskoye, Buturlinskoye thiab Kopanishchenskoye. Lub chalk thickness ntawm tom kawg yog 16.5-85 m. Lub overburden yog cov av-vegetative txheej. Nws thickness yog hais txog 1.8-2 m. Cov chalk txheej muab faib ua ob chav nyob raws kab ntsug. Hauv qab muaj txog li 98% calcium carbonate, nyob rau sab saum toj nws yog me ntsis tsawg - mus txog 96-97.5%.
Thaum kawg homogeneous dawb chalk ntawm Turunian theem tau pom nyob rau hauv Buturlinskoye deposit. Lub thickness ntawm txheej yog 19.5-41 m. Lub overburden thickness ncav cuag 9.5 m. Nws yog sawv cev los ntawm margels, zaub txheej, sandy-clayey formations thiab sandstones. Qhov feem ntawm magnesium thiab calcium carbonates ncav cuag 99.3%. Nyob rau tib lub sijhawm, cov khoom tsis yog carbonate muaj nyob rau hauv ib qho me me.
Cov Stoilenskoye thiab Lebedinskoye tso nyiaj yog qhov txaus siab rau kev lag luam. Hauv cov cheeb tsam no, chalk yog mined li overburden thiab coj mus pov tseg. Kev tsim khoom txhua xyoo yog ntau tshaj 15 lab tons, kwv yees li tsib ntawm lawv tau siv rau hauv kev lag luam hauv tebchaws. Tshwj xeeb, chalk yog nkag rau Starooskol cement cog thiab qee qhov chaw lag luam me. Ntau ntawm cov pob zeb mined ploj hauv cov pob tseg.
Chalk, uas yog nyob rau hauv cov cheeb tsam ntawm cov hlau ore deposits, yog cais raws li zoo raws li cov ntsiab lus ntawm silica thiab carbonate. Nws tuaj yeem siv rau kev lag luam yam tsis muaj kev sib sib zog nqus. Nws yuav tsum tau hais tias nyob rau hauvNyob rau hauv tus txheej txheem ntawm kev tsim cov mining thiab kev lag luam tshwj xeeb hauv cov hlau ore, nws yog ib qho tsim nyog los muab cov txheej txheem thev naus laus zis rau cov chalk rho tawm los ntawm cov khoom lag luam lossis ib qho chaw rau nws cov khoom sib cais.
Kev tsim khoom thiab siv
Cov khoom siv ntawm chalk tau paub ntev. Thaum xub thawj, tus yug tau siv rau hauv kev tsim kho. Txiv qaub tau ua los ntawm nws. Chalk hmoov ua raws li lub hauv paus rau putty, fillers, xim thiab lwm yam. Thaum kawg ntawm lub xyoo pua puv 19, cov tuam txhab ntiag tug tau pib ua haujlwm ntawm White Mountain deposit. Hauv lub qhov cub tawg, cov txiv qaub thiab hmoov tau tsim los ntawm cov pob zeb lumpy. Xyoo 1935, Shebekinsky cog tau tshwm sim, uas tau koom nrog hauv kev tsim cov khoom lag luam rau kev xav tau. Cov khoom muaj txiaj ntsig ntawm chalk tau xav tau hauv hluav taws xob, xim, polymer, roj hmab thiab lwm yam lag luam.
Nrog rau qhov nce hauv kev thov rau cov khoom, cov kev xav tau rau nws qhov zoo tau nce. Cov lag luam uas muaj nyob rau xyoo 1990 tsis tuaj yeem muab kev lag luam nrog cov khoom siv raw uas tsim nyog. Cov tuam txhab ntiag tug tau pib tshwm sim hauv cheeb tsam Belgorod. Lawv cov lej loj yog vim qhov loj ntawm pob zeb tso nyiaj thiab qhov pom tseeb ntawm kev ua haujlwm thev naus laus zis. Txawm li cas los xij, cov txheej txheem tseem ceeb ntawm kev rho tawm thiab kev ua haujlwm tom ntej siv los ntawm cov tuam txhab ntiag tug tsis tuaj yeem muab cov khoom lag luam zoo. Yog li ntawd, ntau lub tuam txhab zoo li no tau kaw. Nyob rau tib lub sijhawm, cov tuam txhab loj tau ua tiav kev tsim kho tshiab thiab kev tsim kho tshiab ntawm lawvkhoom siv. Kev tso tawm cov khoom lag luam zoo tau lees paub hauv 90s los ntawm Belgorod, Petropavlovsk, Shebekinsky nroj tsuag.
Kev tsim cov ntawv zoo
Cov kev xav tau tseem ceeb rau cov khoom lag luam chalk, ntxiv rau qhov kev faib ua feem ntawm carbonates, suav nrog fineness - fineness ntawm kev sib tsoo. Nws yog qhia raws li ib tug seem ntawm sieves ntawm ib tug tej yam me me los yog ib feem ntawm cov hais ntawm ib tug muab me me (piv txwv li, 90% hais nrog ib tug loj ntawm 2 microns).
Qhov tshwm sim ntawm cov kab tsim khoom tshiab rau kev tsim cov xim, roj hmab, polymer thiab lwm yam khoom siv uas chalk siv los ua raw khoom tau ua rau muaj qhov tsis txaus ntseeg ntawm nws cov khoom siv thiab kev noj. Qhov no tshwj xeeb tshaj yog pom nyob rau hauv daim ntawv kev lag luam. Cov lag luam hauv kev lag luam no muaj cov kev cai tshwj xeeb rau cov hmoov av chalk, uas tau hloov kaolin hauv kev tsim khoom.
Qhov teeb meem ntawm cov ntawv pov thawj zoo yog tsom rau cov chaw tsim khoom hauv cheeb tsam Belgorod. Ntxiv nrog rau lub tuam txhab Shebekinsky, uas tsim cov chalk cais, cov nroj tsuag tshiab tau tsim. Yog li ntawd, nyob rau hauv 1995, ib tug txheej txheem cog nyob rau hauv Lebedinsky GOK - ZAO Ruslime. Nws tau tsim raws li Spanish project ntawm lub tuam txhab "Reverte" nrog kwv yees muaj peev xwm ntawm 120 txhiab tons / xyoo. Cov nroj tsuag tsim tawm txog li 10 qib sib txawv ntawm chalk. Nyob rau hauv cov nqe lus ntawm zoo, lawv nyob rau hauv tsis muaj txoj kev inferior rau txawv teb chaws counterparts thiab ua tau raws li thoob ntiaj teb cov qauv. Lub tuam txhab tau nruab nrog cov cuab yeej siv thev naus laus zis niaj hnub tshaj plaws, kev ua haujlwm ntawm cov kab yog tshuab thiab automated.
poIb tsob nroj uas muaj peev xwm ntawm 300,000 tons ntawm cov khoom zoo chalk tau tsim ntawm Stoilensky GOK raws li Mabetex project. Nyob rau tib lub sijhawm, cov phiaj xwm kev lag luam muab rau kev nce ntxiv hauv lub peev xwm.
Ib qho ntawm cov txheej txheem tseem ceeb hauv cov txheej txheem ntawm kev tshuaj xyuas lub cev ntawm lub pob zeb ntawm qhov tso nyiaj tshiab lossis thaj chaw koom nrog hauv cov txheej txheem uas twb muaj lawm yog tus cwj pwm ntawm chalk thaum sib tsoo. Raws li tau hais los saum toj no, hauv cov txheej txheem dej sib txawv, cov khoom muaj cov yam ntxwv sib txawv. Kev pom kev txheeb xyuas qhov sib txawv no tsis tuaj yeem ua tau hauv feem ntau. Kev txiav txim siab tus cwj pwm ntawm chalk nyob rau hauv cov txheej txheem ntawm nws qhuav sib tsoo nyob rau hauv cov txheej txheem thev naus laus zis yog ua los ntawm kev tsim ib qho kev taw qhia ntawm nws blooming nyob rau hauv ib qho chaw ntub dej nyob rau hauv txhua yam kev txiav txim. Cov cuab yeej tshwj xeeb yog siv rau qhov no.
Sodium bicarbonate
Rau nws cov khoom, cov khoom sib txawv yog siv, suav nrog limestone lossis chalk. Cov txiaj ntsig zoo rau lub cev uas sodium bicarbonate muaj yog paub rau ntau tus. Feem ntau nws yog siv rau cov kab mob ntawm cov pos hniav thiab caj pas, kub hnyiab, kom nyias cov hnoos qeev thaum hnoos. Hauv kev lag luam, lub cev muaj zog ntawm dej qab zib thiab chalk yog qhov xav tau zoo. Ob leeg ntawm cov tshuaj no yog siv rau hauv kev tsim kho, kho kom zoo nkauj, cov ntaub ntawv, xim thiab lwm yam khoom. Hais txog kev tsim cov calcium bicarbonate, kev siv chalk ib leeg yog suav tias yog kev xaiv tsis zoo. Raws li tau hais los saum no, tus tsiaj no absorbs noo noo zoo heev,Raws li qhov tshwm sim ntawm uas nws cov yam ntxwv mechanical hloov. Qhov no, nyob rau hauv lem, muaj kev cuam tshuam tsis zoo rau cov txheej txheem thev naus laus zis.
Kuv puas noj CaCO3?
Nws tau ntseeg dav tias cov kws kho mob pom zoo siv chalk kho mob. Cov khoom ntawm cov tshuaj no ntseeg tau tias yuav pab ntxiv cov calcium uas tsis txaus. Ua ntej tshaj plaws, nws yuav tsum tau hais tias cov kws kho mob tsis meej txog qhov no. Feem ntau, cov neeg mob uas nyiam noj chalk (khoom noj) tig mus rau cov kws kho mob tshwj xeeb. Cov khoom tseem ceeb ntawm cov khoom, txawm li cas los xij, yog qhov tsis ntseeg. Kev xav noj nws yuav tshwm sim vim tsis muaj calcium. Txawm li cas los xij, koj yuav tsum paub tias cov yam ntxwv ntawm cov khoom muaj kev hloov pauv loj thaum nws nkag mus rau hauv plab. Dhau los ntawm ntau cov txheej txheem oxidative, nws poob nws qhov nruab nrab nruab nrab thiab hloov mus rau hauv reagent. Hauv nws qhov kev ua, cov tshuaj zoo ib yam li slaked txiv qaub. Yog li ntawd, oxidized chalk pib cuam tshuam rau lub plab mucosa. Nyob rau hauv cov ntaub ntawv no, tsis muaj tshuaj muaj pes tsawg leeg yog manifested. Es tsis txhob, ntawm qhov tsis sib xws. Nws yog tsim nyog nco ntsoov tias cov concentration ntawm calcium nyob rau hauv cov khoom yog siab heev. Raws li qhov tshwm sim, kev siv ntau dhau ntawm chalk tuaj yeem ua rau kom cov hlab ntsha. Hauv qhov no, cov kws kho mob pom zoo kom hloov nws nrog calcium gluconate lossis cov tshuaj zoo sib xws. Raws li kev tshem tawm ntawm lub siab, raws li ntau tus neeg uas tau sim nws nrog chalk, nws tsis pab.
Kev lag luam thiab siv tsev nyob
Mel ua raws liib qho tseem ceeb ntawm cov ntawv, uas yog siv rau hauv kev luam ntawv. Lub siab dispersion ntawm calcium carbonate nyob rau hauv crushed daim ntawv muaj feem xyuam rau lub optical thiab luam ntawv yam ntxwv, porosity, thiab smoothness ntawm cov khoom. Vim muaj cov chalk, abrasiveness ntawm cov khoom txo. Cov pob zeb hauv av yog dav siv rau cov phab ntsa ntxuav dawb, ciam teb, thiab tiv thaiv ntoo. Chalk yog siv nyob rau hauv purification ntawm beet kua txiv, uas, nyob rau hauv lem, yog siv nyob rau hauv lub match kev lag luam. Rau cov laj thawj no, raws li txoj cai, lub pob zeb hu ua precipitated yog tsim nyog. Xws li chalk tau txais tshuaj los ntawm cov zaub mov muaj calcium. Nrog rau lwm cov pob zeb carbonate, cov khoom siv hauv iav melting ua ib qho ntawm cov khoom siv. Vim lub chalk, thermal stability ntawm cov khoom, nws cov neeg kho tshuab lub zog thiab stability thaum raug huab cua thiab reagents yog nce. Cov tsiaj yog dav siv nyob rau hauv kev tsim cov chiv. Chalk kuj ntxiv rau tsiaj pub.
Roj hmab kev lag luam
Chalk yog thawj qhov chaw ntawm tag nrho cov fillers siv hauv kev lag luam. Qhov no feem ntau yog vim qhov tseeb tias kev siv cov khoom siv raw no yog kev lag luam zoo. Chalk muaj tus nqi qis. Nyob rau tib lub sijhawm, nws cov kev taw qhia rau cov khoom siv roj hmab tsis ua rau muaj kev phom sij. Qhov thib ob yog vim li cas rau qhov muaj koob meej ntawm cov khoom siv raw hauv kev lag luam yog kev siv thev naus laus zis. Chalk ua kom yooj yim rau cov txheej txheem ntawm kev tsim cov khoom siv roj hmab. Tshwj xeeb, vim nws, vulcanization yog nrawm, ntocov khoom ua kom du. Cov tsiaj kuj tau siv dav hauv kev tsim cov sponge thiab ntxeem tau roj hmab, cov khoom yas, tawv hloov, thiab lwm yam.
