Ciminter clinker

Ciminter clinker abu ne mai ƙarfi wanda aka samar  masana'antar Ciminti na Portland a matsayin samfurin matsakaici. Clinker yana faruwa a matsayin kumfa ko nodules, yawanci 3 millimeters (0.12 in) zuwa 25 millimeters (1.98 in) a diamita. Ana samar da shi ta hanyar sintering (haɗe tare ba tare da narkewa ba har zuwa ma'anar liquefaction) dutse mai laushi da kayan aluminosilicate kamar yumɓu a lokacin matakin murhu na siminti.

Composition da shirye-shiryensa
Portland clinker yawanci yana ƙunshe da ma'adanai guda huɗu: nau'ukan calcium silicate guda biyu, alite (Ca3SiO5) da belite (Ca2SiO4), tare da tricalcium aluminate (Ca3Al2O6) da calcium aluminoferrite (Ca2(Al,Fe)2O5). Ana samar da waɗannan manyan nau'ikan ma'adanai ne ta hanyar dumama clay da limestone a babban zafi.Siegbert Sprung, "Cement" in Ullmann's Encyclopedia of Industrial Chemistry, 2012, Wiley-VCH, Weinheim. 

Babban kayan da ake amfani da shi don yin clinker yawanci shi ne limestone da aka gauraya shi da wani kayan da ke ɗauke da clay a matsayin tushen alumino-silicate. Ana iya amfani da limestone mara tsabta wanda ke ɗauke da clay ko silicon dioxide (SiO2). Abun calcium carbonate (CaCO3) da ke cikin irin waɗannan limestone na iya raguwa zuwa kashi 80% ta nauyi. A yayin aikin calcination da ake yi wajen samar da clinker, limestone yana tarwatsewa zuwa lime (calcium oxide), wanda ke shiga cikin samfuran ƙarshe na clinker, sannan carbon dioxide ya tashi zuwa sararin sama.

Kayan aiki na biyu (kayan da ke cikin rawmix banda limestone) ya danganta da tsabtar limestone. Wasu daga cikin kayan aikin na biyu da ake amfani da su sun haɗa da: clay, shale, sand, iron ore, bauxite, fly ash da slag.

Portland cement clinker ana yin sa ne ta hanyar dumama gaurayen kayan aiki na farko a cikin rotary kiln a babban zafi. Kayan da sakamakon sinadarai suka samar suna haɗuwa a lokacin sintering, kusan . Aluminium oxide da iron oxide suna nan ne kawai a matsayin flux don rage zafin sintering kuma suna ba da ƙaramin gudummawa ga ƙarfin siminti.

Don simintin musamman, irin su nau'in low heat (LH) da sulfate resistant (SR), dole ne a rage yawan tricalcium aluminate da ake samarwa.

Ana tantance clinker da yadda yake yin hulɗa da ruwa ta hanyar dabaru da yawa, ciki har da calorimetry, ci gaban ƙarfin matsawa, X-ray diffraction, scanning electron microscope da atomic force microscopy.

 Amfani da shi 
Portland cement clinker (abbreviated k a cikin ka'idojin Turai) an niƙa shi zuwa foda mai kyau kuma ana amfani dashi azaman mai ɗaurewa a cikin samfuran siminti da 63" href="./Grinding_operations" id="mwYQ" rel="mw:WikiLink" title="Grinding operations">ƙasa. Dole ne a kara karamin gypsum (kasa da 5 wt.%) don kauce wa saitin walƙiya na tricalcium aluminate (Ca3Al2), mafi yawan ma'adinai masu saurin amsawa (haɗin ruwa mai zafi) a cikin Portland clinker. Hakanan ana iya haɗa shi da wasu sinadaran aiki ko ƙarin siminti don samar da wasu nau'ikan siminti ciki har da, bin ma'aunin EN 197-1 na Turai: 

 CEM I: tsarkake Portland clinker (Ordinary Portland Cement, OPC) 
 CEM II: sinadarin siminti tare da iyakantaccen kari na cika dutse ko ƙanƙara mai fashewa (BFS) 
 CEM III: BFS-OPC flast furnace ciment
 CEM IV: ciment na pozzolanic
 CEM V: sinadarin ciment (tare da manyan kari na BFS, toka mai tashi, ko silica hayaki) 

Clinker yana daya daga cikin sinadaran dutse na wucin gadi wanda ke kwaikwayon dutse mai laushi kuma ana kiransa pulhamite bayan mai kirkirarsa, James Pulham (1820-1898). Sauran sinadaran sune siminti da yashi na Portland. Pulhamite na iya zama mai gamsarwa sosai kuma ya shahara wajen kirkirar lambunan dutse masu kama da na halitta a karni na sha tara.

Clinker, idan an adana shi a yanayin bushe, ana iya adana shi na watanni da yawa ba tare da asarar inganci ba. Saboda wannan, kuma saboda ana iya sarrafa shi cikin sauƙi ta hanyar kayan aiki na yau da kullun, ana sayar da clinker a duniya da yawa. Masana'antun siminti da ke sayen clinker yawanci suna niƙa shi azaman ƙari ga nasu clinker a tsire-tsire na siminti. Masu sana'a kuma suna jigilar clinker zuwa tsire-tsire masu niƙa a wuraren da ba a samun albarkatun siminti ba.

 Kayan gyaran Clinker 

Gypsum is added to clinker primarily as an additive preventing the flash settings of the cement, but it is also very effective to facilitate the grinding of clinker by preventing agglomeration and coating of the powder at the surface of balls and mill wall.[<span title="This claim needs references to reliable sources. (May 2022)">citation needed</span>]

Ana kuma ƙara mahadi na kwayoyin halitta sau da yawa a matsayin kayan aikin niƙa don kauce wa tarwatsa foda. Ana amfani da Triethanolamine (TEA) a 0.1 wt. % kuma ya tabbatar da cewa yana da tasiri sosai. Ana amfani da wasu kayan karawa a wasu lokuta, kamar su ethylene glycol, oleic Aceit, da dodecyl-benzene sulfonate.  

 Rashin ruwa na ma'adanai na Clinker 
Bayan kara ruwa, ma'adanai na clinker suna amsawa don samar da nau'ikan hydrates daban-daban da kuma "saita" (mai ƙarfi) yayin da sinadarin siminti mai ruwa ya zama kankare. Calcium silicate hydrates (C-S-H) (hydrates na Alite da ma'adanai na belite) suna wakiltar manyan abubuwan "glue" na kankare. Bayan saitawa na farko siminti yana ci gaba da karuwa da haɓaka ƙarfin inji. 

Kwanaki 28 na farko sune mafi mahimmanci ga karfafawa. Kayan ba ya bushewa amma mutum ya ce yana saita kuma yana da ƙarfi. Ciminti mai ɗaure ruwa ne wanda ruwa ke buƙatar ruwa. Zai iya saita shi sosai a ƙarƙashin ruwa. Ruwa yana da mahimmanci ga karfafawa kuma dole ne a guje wa asarar ruwa a ƙuruciya don kauce wa ci gaban fashewa. Ana kare ƙaramin ƙarfe daga bushewa (rashin ruwa mara ƙarfi). Hanyoyin gargajiya don hana bushewa sun haɗa da rufe samfurin tare da rigar burlap ko amfani da filastik.

Don manyan ayyukan, kamar manyan hanyoyi, ana yayyafa farfajiyar tare da mafita na warkarwa wanda ke barin rufin ruwa mai hana ruwa.

 Gudummawa ga dumamar yanayi 
Ya zuwa 2018, samar da siminti ya ba da gudummawa game da 8% na duk hayakin carbon a duk duniya, yana ba da guddina sosai ga dumamar duniya. Yawancin waɗannan hayakin an samar da su ne a cikin tsarin masana'antar clinker.

 Dubi kuma 

 Clinker (sharar gida) 
 Tasirin muhalli na kankare

 Bayanan da aka ambata 

Rukuni:Shafuka masu fassarorin da ba'a duba ba