Melao-motheo ea Motheo ea Khauta ea Cyanidation Leaching

Ho ntšoa ha khauta ka letsoai, e leng ts'ebetso ea bohlokoa ea hydrometallurgical, e bile lejoe la motheo la ho ntšoa ha khauta ka lilemo tse fetang lekholo ho tloha ha e rekisoa ka bo-1890. Sengoloa sena se hlahloba mekhoa ea mantlha ea lik'hemik'hale le ea 'mele e tšehetsang ho ntšoa ha khauta ka letsoai, e fanang ka kutloisiso e felletseng ea mokhoa ona oa bohlokoa indastering ea merafo ea khauta.

Liphetoho tsa Lik'hemik'hale: Pelo ea Cyanidation

Ts'ebetso ea cyanidation e itšetlehile ka ts'ebetso e ikhethang ea khauta moo ho nang le li-ion tsa cyanide (CN⁻) le oxidant, eo hangata e leng oksijene e tsoang moeeng. Karabelo ea motheo ea lik'hemik'hale e ka akaretsoa ka tsela e latelang: Li-moles tse 'ne tsa khauta (Au), tse arabelang le li-moles tse robeli tsa Sodium Cyanide (NaCN), mole e le 'ngoe ea oksijene (O₂) e tsoang moeeng, le li-moles tse peli tsa metsi (H₂O), li hlahisa li-moles tse 'ne tsa sodium dicyanoaurate(I) (Na[Au(CN)₂]) le li-moles tse 'ne tsa sodium hydroxide (NaOH).

Karabelong ena, liathomo tsa khauta li oxidized ho ea boemong ba oxidation ea +1 'me li theha li-complexes tse tsitsitseng tsa dicyanoaurate(I) \([Au(CN)_2]^- \). Li-ion tsa cyanide li sebetsa e le li-agent tse rarahaneng, li tsitsisa li-ion tsa khauta ka har'a tharollo, ha oksijene e sebetsa e le moamoheli oa lielektrone, e khanna oxidation ea khauta. Mokhoa ona oa redox - complexation o nolofalletsa ho qhibiliha ha khauta ka khetho ho tsoa lirafshoeng tsa eona, esita le maemong a tlaase a cyanide (0.01 - 0.1%).

Mekhoa ea 'Mele: Phetisetso ea Boholo le Leaching Kinetics

Ka nqane ho dikarabelo tsa dikhemikhale, bokgoni ba ho ntsha kgauta bo laolwa ke ditshebetso tsa mmele tse kang phetiso ya bongata le ho hasana. Sekgahla sa ho ntsha kgauta ka kakaretso se susumetswa ke ho hasana ha di-reactants (cyanide le oksijene) ho ya bokahodimo ba kgauta le ho hasana ha di-complexes tse bopilweng tsa dicyanoaurate hole le bokahodimo. Ho ya ka mohlala wa ho fokotseha ha kgauta, ho ntsha kgauta ho etsahala ka mehato e meraro e latellanang:

1. Phetiso ea boima ba kantle : Cyanide le oksijene lia ata ka lera la moeli le potolohileng karoloana ea khauta.

2. Karabelo ea bokaholimo : Ho oksida le ho rarahana ho etsahala sebakeng sa khauta le tharollo.

3. Ho hasana ha ka hare : Metswako ya kgauta e bopilweng le cyanide e hasanya ka ntle ho karoloana. Mehato e liehang ka ho fetisisa ho ena e etsa qeto ya sekgahla sa ho dutla ha metsi ka kakaretso, hangata e le phetiso ya boima ba kantle kapa karabelo ya bokahodimo, ho itshetlehile ka maemo a tshebetso.

Lintlha tse nang le Tšusumetso ho Matla a Cyanidation

Lintlha tse 'maloa tsa bohlokoa li ama haholo ts'ebetso ea khauta ea cyanidation:

• Ho Hlohlelletsa ha Cyanide : Ho hlokahala cyanide e lekaneng ho theha metsoako e tsitsitseng, empa bongata bo feteletseng bo ka lebisa litšenyehelong tse eketsehileng le matšoenyehong a tikoloho. Ho hlohlelletsa hantle ho fapana ho latela litšobotsi tsa tšepe.

• Ho fumaneha ha oksijene : Phepelo e lekaneng ea oksijene e bohlokoa bakeng sa karabelo ea oxidation. Mekhoa ea ho kenya moea, joalo ka ho sisinyeha ha mechini kapa ho fokotsa moea, e sebelisoa ho ntlafatsa phetiso ea oksijene.

• Taolo ea pH : Ts'ebetso ena hangata e etsoa ka pH e phahameng (9 - 11) ho thibela ho thehoa ha khase e chefo ea hydrogen cyanide (HCN). Kalaka e sebelisoa hangata ho boloka boemo ba pH bo lakatsehang.

• Mineralogy ea Maruo : Boteng ba li-sulfide, thepa ea aceous ea carbon , le liminerale tse ling li ka sitisa cyanidation. Mohlala, li-sulfide li ka ja cyanide le oksijene, ha lintho tse nang le carbonaceous li ka monya metsoako ea khauta le cyanide, tsa baka "ho monya" lintho tse ling.

Mekhoa ea ho Ntlafatsa Ts'ebetso ea Cyanidation

Ho ntlafatsa ts'ebetso e ntle ea ho ntšoa ha khauta, mekhoa e fapaneng ea ntlafatso e sebelisoa:

• Pele ho kalafo : Ho besa, ho oxidation ka kgatello, kapa ho oxidation ka bio ho ka sebediswa majweng a kgahlanong le kgatello ho tlosa diminerale tse sitisang le ho pepesa bokahodimo ba kgauta.

• Lintho tse eketsoang : Metswako e kang thiourea kapa ammonia e ka eketsoa ho ntlafatsa sekhahla sa ho qhibiliha kapa ho thibela dikarabelo tse ka thoko.

• Moralo o Ntlafaditsweng wa Disebediswa : Di-reactor tse tswetseng pele tsa ho ntsha metsi tse nang le bokgoni bo ntlafetseng ba ho kopanya le ho fetisetsa bongata, jwalo ka di-reactor tsa ditanka tse sisinyehileng kapa ditsamaiso tsa ho ntsha metsi tse ngata, di ka ntlafatsa tshebetso yohle ya tshebetso.

Qetellong, khauta ea cyanidation leaching ke ts'ebetso e rarahaneng empa e sebetsa haholo e kopanyang karabelo ea lik'hemik'hale, phetiso ea boima ba 'mele, le taolo e hlokolosi ea liparamente tse ngata tsa ts'ebetso. Ho utloisisa melaoana ena ea mantlha ho bohlokoa bakeng sa ho ntlafatsa ts'ebetso ea ho rala khauta, ho netefatsa ts'ebetso ea moruo, le ho fokotsa litlamorao tsa tikoloho indastering ea merafo ea khauta. Ha tlhoko ea khauta e ntse e tsoela pele, lipatlisiso tse tsoelang pele li shebane le ho nts'etsapele mekhoa ea cyanidation e sebetsang hantle haholoanyane, e tšoarellang, le e baballang tikoloho.