Uranium

Uranium karfe ne mai nauyi wanda ake amfani da shi a matsayin wadatacciyar hanyar samar da makamashi tun sama da shekaru 60. Uranium yana samuwa a mafi yawan duwatsu cikin adadin ɓangarori 2 zuwa 4 a kowace miliyan ɗaya na makamashin, kuma yana da yawa a sararin doron ƙasa na duniya kamar yadda sinadaran tin da tungsten da molybdenum suke. Uranium yana samuwa har a cikin ruwan kogi, kuma ana iya samun shi a tekuna.

An gano Uranium a shekara ta 1789, Martin Klaproth, masanin kimiyya ɗan ƙasar Jamus, shi ne ya gano shi, a cikin ma’adinai mai suna pitchblende. An samo sunan Uranium daga duniyar Uranus.

An tabbatar da samuwar Uranium a cikin supernovae kimanin shekaru biliyan 6.6 da suka wuce. Duk da yake bai zama gama-gari ba a tsarin solar system, a yanzu yana jinkirin lalacewa saboda radiation, dalilin da ke samar da  zafi a duniya, yana haifar da ɗumamar yanayi na nahiyoyi.

Uranium yana narkewa a yanayin zafin digiri 1132 ° a ma’aunin celsius. Kuma tambarin sinadaran uranium shi ne U.

Ƙwayar zarrar Uranium (Uranium atom)

A kan ma’aunin da aka tsara bisa ga ƙaruwar yawan sinadaran samuwarsa, uranium yana ɗaya daga cikin mafi nauyi a cikin dukkan sinadaran da ke samuwa, (hydrogen shi ne mafi ƙarancin nauyi). Uranium ya ninku a nauyi sau 18.7 idan aka kwatanta da ruwa.

Nau’ikan Uranium

Kamar sauran abubuwa, uranium yana samuwa a cikin nau’i-nau’i daban-daban da aka sani da ‘isotopes’. Waɗannan isotopes sun bambanta da juna a cikin adadin ƙwayoyin halitta marasa sinadarin lantarki (neutrons) a cikin tsakiya. Uranium na asali kamar yadda ake samu cikin doron ƙasa na duniya shi ne haɗakar isotopes guda biyu: uranium-238 (U-238), mai ɗauke da kashi 99.3% da uranium-235 (U-235) mai kimanin kashi 0.7%.

Isotope U-235 yana da mahimmanci saboda a wasu yanayi ana iya raba shi da sauri, yana ba da makamshi mai yawa. Don haka za iya cewa shi ne ke zama sinadarin ‘fissile’ wanda ake amfani da kalmar ‘fission nuclear’ a kimiyyance.

A halin yanzu, kamar duk isotopes da ke tsarin radioactive, suna lalacewa. U-238 yana ruɓewa sannu a hankali, rabin rayuwarsa tana kusan daidai da shekarun duniya (shekaru miliyan 4500). Wannan yana nufin cewa yana da ƙarancin radioactives, ƙasa da yawan isotopes a cikin duwatsu da ƙasa. Duk da haka yana samar da kaso 0.1 watts/ton a matsayin zafi, kuma wannan ya isa ya ɗumama duniya. U-235 yana raguwa da sauri.

Makamashi a cikin uranium

A tsakiyar U-235 ya ƙunshi 92 protons da 143 neutrons, wato (92 + 143 = 235). Lokacin da tsakiyar makamshin U-235 ya ɗauki neutron mai motsi ya rabu gida biyu (fissions), kuma ya fitar da wani makamashin a cikin nau’i na zafi, to ana watsar da neutron biyu ko uku. Idan isassun waɗannan neutrons da aka watsar suka haifar da rarrabuwar sauran sinadaran makamshin U-235, za su fitar da ƙarin neutrons, za a iya samun fission wato ‘chain reaction’. Lokacin da wannan ya faru akai-akai sau miliyoyi, zafi mai yawa yana samuwa daga ƙanƙanin adadin uranium.

Uranium da plutonium

Kasancewar U-235 tsakiyarsa shi ne ‘fissile’, na U-238 kuma shi ne ‘fertile’. Wannan yana nufin cewa zai iya kama ɗaya daga cikin neutrons da ke yawo a cikin tsakiyar reactor kuma ya zama  plutonium-239 (amma ba kai tsaye ba), wanda shi ne fissile. Pu-239 yana kama da U-235 sosai, saboda takan yi fissions lokacin da neutron ya buge shi kuma hakan yana haifar da adadin makamshi iri ɗaya.

Saboda akwai da yawa U-238 a cikin reactor core (mafi yawan man fetur), waɗannan reactions suna faruwa akai-akai, kuma a zahiri kusan kashi ɗaya bisa uku na yawan makamashin man fetur ya fito ne ta hanyar ƙonewar Pu-239.

Amma wani lokacin ƙwayar zarra ta Pu-239 kawai tana kama neutron ba tare da tsagewa ba, kuma ya zama Pu-240. Saboda Pu-239 ko dai ya ci gaba da ƙonewa ko kuma ya zama Pu-240, idan mai ya daɗe a cikin reactor yana da ƙarin Pu-240 a ciki. (Mahimmancin hakan shi ne idan aka cire man da aka kashe bayan kimanin shekaru uku, plutonium da ke cikinsa bai dace da ƙera makamai ba amma ana iya sake yin amfani da shi a matsayin mai).

Haƙowa da sarrafa uranium

Ana iya haƙo ma’adinin Uranium ta hanyar ƙarƙashin ƙasa ko wasu hanyoyin gwargwadon zurfinsu. Bayan haƙar makamshin, ana niƙasa da ƙasa. Sa’an nan kuma a bi da shi da sinadarin acid don narkar da uranium ɗin.

Haka nan ana iya haƙar uranium ta hanyar in situ leaching (ISL), inda ake narkar da shi daga wani lallausan ƙarfe na ƙarƙashin ƙasa, a wurin kuma a jujjuya shi zuwa sama-sama.

Matakin ƙarshen na sarrafa makamashin uranium daga haƙowa, shi ne ya koma uranium oxide concentrate (U3O8). Wannan shi ne sigar da ake sayar da uranium.

Uranium zuwa man fetur

Kafin a yi amfani da shi a cikin na’ura don samar da wutar lantarki, dole ne a bi matakan sarrafawa don samar da man fetur mai amfani.

Ga mafi yawan ma’aikatun da ke samar da makamashi a duniya, mataki na gaba na samar da man shi ne a mayar da uranium oxide zuwa gas, uranium hexafluoride (UF6), wanda ke ba da damar inganta shi. Ingantuwarsa tana haɓaka ƙaruwar isotope na uranium-235 daga matakinsa na asali,  wato 0.7% zuwa 4-5%. Wannan yana ba da damar ƙwarewar fasaha mafi girma a ƙirar sinadarin da kuma sarrafawa, musamman a cikin manyan sinadarai kuma yana ba da damar amfani da ruwa a matsayin mai daidaitawa.

Bayan an inganta, iskar UF6 tana jujjuya zuwa uranium dioxide (UO2) wanda aka sanya ya zama pellet ɗin mai. Ana sanya waɗannan pellet ɗin mai a cikin bututun ƙarfe sirara, waɗanda aka sani da fuel rods, waɗanda aka haɗa a tsari dami. A  babbar ma’aikatar sarrafa makamashi ana iya samun fuel rods 51,000 tare da pellet sama da miliyan 18.

Albarkatun Uranium na wasu ƙasashe a cikin shekarar 2021

Manazarta

Admin. (2022a, August 8). Uranium – Uses, Chemical & Physical Properties, Definition, Facts  – Periodic Table. BYJUS.

World Nuclear Association. (n.d.) What is Uranium? How Does it Work?