I-Bauxite Beneficiation Electrostatic

Aluminium yisona esikhulunywa abantu abaningi isici metal wathola Emhlabeni, ingqikithi mayelana 8% uqweqwe eMhlabeni. Nokho, i-aluminium njengengxenye iyasebenza futhi ngenxa yalokho ayenzeki ngokwemvelo – idinga ukucolisiswa ukukhiqiza insimbi ye-aluminium. Okuxhunyanwa sokuqala zethu ezingokwenyama aluminium yokucwenga kuyinto bauxite, umthombo emhlabeni main commercial-aluminiyamu. I-Bauxite iyidwala elisetshenzisiwe, futhi iqukethe ikakhulukazi i-aluminium mineral gibbsite (Al(OH)3), boehmite (c-Alo(OH)) futhi diaspore (a-Alo(OH)), futhi ivame ukuxutshwa nezinsimbi ezimbili ze-oxide goethite ne-hematite, i-aluminium yobumba yamaminerali kaolinite kanye namanani amancane we-anatase (TiO2) kanye / noma ilmenite (FeTiO3).

bauxite beneficiation

ezifakwa bauxite kukhona ukusabalala emhlabeni wonke, ikakhulukazi okwenzeka ezindaweni ezinamahlathi emvula noma nakwezifudumele. Yize okulondoloziwe okutholakele kwe-bauxite kulindeleke ukuthi kuhlale iminyaka eminingi, izinga lezokuvikela ukuthi kungenziwa kwezomnotho afinyelelwe liyancipha. Ukuze refiners, who are in the business of bauxite processing to make alumina, nensimbi ekugcineni aluminiyamu, lokhu kuyinselele kokubili nemithelela zezimali kanye nezemvelo.

Inqubo yokuhlanza i-metallological bauxite ku-alumina ifaka okulandelayo:

  • I-Bauxite ore
  • I-Caustic soda – sodium hydroxide amakhemikhali (NaOH)
  • Amandla (inqubo yokuhlaziya idinga ukushisa kanye nengcindezi)
  • Amanzi amasha

Imiphumela elandelayo iyenziwa:

  • Alumina (Al2O3)
  • Izinsalela zokuhlanza i-Alumina (Fika) noma udaka obomvu
bauxite processing

Inqubo esetshenziswa kakhulu yamakhemikhali yokuhlanza i-bauxite ibe yi-alumina, inqubo yeBayer, kufaka phakathi ukucibilika kwe-Al2O3 edwaleni le-bauxite nge-caustic soda (NaOH) emazingeni okushisa aphakeme nengcindezi. Ingxenye ye-Al2O3 ye-bauxite ichithwa isixazululo, ukuze kamuva kukhishwe njenge-alumina. Nokho, i-bauxite ebangeni eliphakeme iqukethe kuze kube 60% Al2O3, futhi imali eningi esebenza nge-bauxite ingaphansi kwalokhu, ngezinye izikhathi njengoba low 30-40% Al2O3. Ngoba umkhiqizo owuthandayo ungukuhlanzeka okuphezulu kwe-Al2O3, the oxides ezisele bauxite (Fe2O3, SiO2, TiO2, Izinto eziphilayo) zihlukaniswe ne-Al2O3 futhi zenqatshwa njengokuhlala indawo yokuhlanza i-alumina (Fika) noma udaka obomvu. Ngenjwayelo, ikhwalithi ephansi bauxite (okungukuthi okuqukethwe kwe-Al2O3 okuphansi) udaka obomvu xaxa lwenziwa ithoni ngayinye yomkhiqizo we-alumina. Ngaphezu kwalokho, ngisho namaminerali athile we-Al2O3 athela amaminerali, ephawuleka kaolinite, ukhiqize ukusabela okuvela eceleni okungafuneki ngesikhathi senqubo futhi kuholela ekwandeni kwesizukulwane sodaka obomvu, kanye nokulahlekelwa ezibizayo caustic soda chemical, kwenombolo izindleko ezinkulu kule bauxite yokucwenga inqubo.

udaka olubomvu noma Fika simele esikhulu ku-uya inselele ngemboni aluminium. udaka olubomvu iqukethe abalulekile caustic asalile okusalile chemical ekucwengisisweni, futhi ane-alikhali kakhulu, ngokuvamile line-pH 10 - 13. Kukhiqizwa ngamanani amakhulu emhlabeni jikelele – ngokusho kwe-USGS, Kulinganiselwa ukukhiqizwa alumina global kwaba 121 amathani ayizigidi ezingu-e 2016. Lokhu kungenzeka kuholele kokunye 150 amathani ayizigidi ezingu udaka olubomvu elakhiwe phakathi nenkathi efanayo. Naphezu ucwaningo okuqhubekayo, udaka olubomvu okwamanje Imbalwa izindlela elizimele ukuba nenzuzo kabusha ukusetshenziswa. Kulinganiselwa ukuthi kakhulu kancane udaka olubomvu kuyinto ngokunenzuzo kabusha esetshenziswa emhlabeni wonke. Esikhundleni salokho udaka olubomvu luyaphonswa kusuka ekuchumeni kwe-alumina lube yimigodi yokugcina izinto noma ekuchithekeni komhlaba, lapho agcinwe futhi ziqashwe ngezindleko ezinkulu.

Ukulahleka ezibizayo soda caustic (NaOH) kanye nesizukulwane sodaka obomvu kuhlobene nekhwalithi ye-bauxite esetshenziselwa inqubo yokucoca. Ngenjwayelo, engezansi okuqukethwe kwe-Al2O3 kwe-bauxite, elikhulu ivolumu udaka olubomvu ukuthi lizokhiqizwa, njengoba izigaba ezingezona i-Al2O3 zenqatshwa njengodaka obomvu. Ngaphezu kwalokho, ukuphakama kokuqukethwe kwe-kaolinite noma okusebenzayo kwe-bauxite, odakeni elibomvu ngaphezulu lizokhiqizwa. Okuqukethwe kwe-silica okusebenzayo kungakhuphulisi umthamo wodaka obomvu, kodwa futhi idla i-caustic soda reagent futhi inciphise isivuno se-Al2O3 esibuyiselwe ku-bauxite. Ngakho-ke, kukhona zombili impikiswano yezomnotho nezemvelo okufanele yenziwe ukuze kuthuthukiswe ikhwalithi ye-bauxite ngaphambi kokucwengwa.

Inqubo STET ezomile ngokwahlukana izipesheli bauxite abakhiqizi noma refiners bauxite ithuba ukwenza pre-Bayer-inqubo ngcono ore bauxite ukuthuthukisa ikhwalithi. Le ndlela kunezinzuzo eziningi:

  • Ukuncishiswa kwezindleko zokusebenzisa ka femu ngenxa ukusetshenziswa aphansi of soda caustic ngokunciphisa okokufaka Silica esisheshayo.
  • Ukonga amandla ngesikhathi sokucwilisa ngenxa yevolumu ephansi yama-inert oxides (Fe2O3, TiO2, I-SiO2 engasebenzi) engena bauxite. Ukugeleza okuncane kwesisindo se-bauxite kuya ekuhlanzeni kuholela emandleni amancane okushisa nokuxineka.
  • Ukwehliswa kwevolumu yokudala udaka obomvu (okungukuthi – obomvu odakeni alumina isilinganiso) ngokususa i-silica esebenzayo kanye ne-inert oxides.
  • Ukulawulwa okuqinile kwekhwalithi yokufaka ye-bauxite yokuhlanza kunciphisa inqubo yokuphakama futhi kuvumela abahlaziyi ukuthi babhekise izinga elifanelekile le-silika elisebenzayo ukuze bandise ukwenqatshwa okungcolisiwe.
  • Ukulawulwa kwekhwalithi okuthuthukisiwe kokuphakelayo kwe-bauxite kuya ekuhlanzeni kunciphisa inqubo yokuphakama, kwandisa isikhathi nesikhathi nokukhiqiza.
  • Ukwehliswa kwethamo lodaka olubomvu kuhumusha ekuphathweni okuncane nezindleko zokulahla kanye nokusetshenziswa okungcono kokulahlwa komhlaba okukhona.
  • Ngokungafani udaka olubomvu, tailings inqubo ezomile electrostatic awuqekethe amakhemikhali futhi ungameli wesikhathi eside kwemvelo isitoreji isibopho sezomthetho.
  • Ngokungafani udaka olubomvu, dry by-products/tailings from a bauxite processing operation can be utilized in cement manufacture as there is no requirement to remove the sodium, okuyinto elimaza usimende womshini. Empeleni – I-Bauxite isivele iyinto evamile eluhlaza okwenziwe ngayo ePortland usimende.
  • Nwebisa impilo yokusebenza kwemayini ekhona ye-bauxite ngokuthuthukisa ukusetshenziswa kwe -ryry nokukhulisa ukululama.
  • I-STET yindleko ephansi yokusebenza, inqubo ephezulu yokuqhubeka. Akukho manzi noma amakhemikhali adingekayo.

Ngokufigqiwe, ukucutshungulwa ezomile kanye namathuba STET isihlukanisi izipesheli ukukhiqiza value kubakhiqizi bauxite futhi refiners. Pre-ukucutshungulwa bauxite ngaphambi yokucwenga kuzonciphisa izindleko chemical, wehlise ivolumu udaka olubomvu elakhiwe futhi unciphise inqubo izinkinga.

Izinkomba:

  • Raju, K. S. 2009. Imithombo ye-Bauxite eNdiya, I-Aluminium Association of India, I-Bangalore, India
  • IHausberg, J., Thabile, U., Meyer, F.M. 1999. Ikhwalithi ye-Bauxite kanye nomphumela wayo ku-Red Mud Ekhiqizwa ngesikhathi se-Alumina Production, 1999, I-International Symposium Yezingqinamba Zezemvelo Nezezomnotho, Ukraine, Juni 1999.
  • I-USGS Minerals Yearbook 2016, Umqulu I, Umbiko Wempahla, I-Bauxite ne-Alumina 2016.
  • IBagshaw, A. N., Indaba ye-Aluminium, I-Bauxite eya ku-Alumina: Inqubo yeBayer, Umbhalo wesingeniso, Okthoba 2017
  • Bangani, A., Kildea, J., The, T., noPhillips, E., Ukuphathwa nokulawulwa kweSilica kwinqubo yeBayer, Ukuqhubeka kwe-9th International Alumina Quality Workshop, 2012, kk 93-97

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