Ukusetshenziswa Kwesodium Cyanide Ekukhishweni Kwegolide Kuchaziwe

Enqubweni yokukhipha igolide kuma-cyanide compounds, I-sodium cyanide idliwe ngezindlela eziningi. I-sodium cyanide isetshenziswa kakhulu i-ejenti yokuhlanza ekukhishweni kwegolide, futhi ngokwethiyori, amagremu angu-0.5 kuphela I-Sodium Cyanide iyadingeka ukuze leach 1 gram yegolide. Kodwa-ke, ezitshalweni eziningi zegolide ze-cyanidation, ukusetshenziswa kwangempela kwe-cyanide kuphakeme kakhulu, ngokuvamile kudlula izibalo zethiyori izikhathi ezingu-50 kuya kweziyi-100.

Izici eziyinhloko ezinomthelela ekusetshenzisweni okuphezulu kwe-cyanide emzimbeni inqubo yegolide ye-cyanidation zihlanganisa:

1. Ukusetshenziswa Kwe-Cyanide Enqubweni Yokuchithwa Kwegolide

Izitshalo ze-cyanide bezilokhu zisetshenziswa i-sodium cyanide ukuncibilikisa igolide etsheni ukuze kutholwe igolide kumvukuzi. Ukusabela kwamakhemikhali okuhilelekile kumi kanje:

• [2Au+4NaCN+O2+2H2O→2Na[Au(CN)2]+2NaOH+H2O2]

• [ 2Au+4NaCN+H2O2→2Na[Au(CN)2]+2NaOH]

Kusukela ekuphenduleni kwe-electrochemical, kuyaziwa ukuthi ukuncibilikisa igremu elingu-1 legolide kudinga ukusetshenziswa kwamagremu angu-0.92 we-sodium cyanide.

2. Ukusetshenziswa kwe-Cyanide Ekuphenduleni Ngezinsimbi Eziyisisekelo Ezihlangene

(1) Amanye amatshe egolide aqukethe amaminerali ahlobene njenge-pyrite, i-magnetite, i-chalcopyrite, amaminerali e-sulfate, ama-hydroxides, nama-oxides. Phakathi nesigaba sokuchotshozwa, i-iron powder ikhiqizwa, esabela kancane kancane nge-sodium cyanide, ikhula ukusetshenziswa kwe-cyanide. Ukusabela kungokulandelayo:

• [ FeS2+NaCN→FeS+NaCNS]

• [ Fe(OH)2+2NaCN→Fe(CN)2+2NaOH]

• [ Fe+6NaCN+2H2O→Na4Fe(CN)6+2NaOH+H2↑]

• [S+NaCN→NaCNS]

(2) Uma i-ore yegolide iqukethe izinhlobo ezahlukene zamaminerali ethusi, zizophinde zihlangane ne-sodium cyanide ukuze zenze ama-copper cyanide complexes, adle i-cyanide kule nqubo. Ukusabela kungokulandelayo:

• [ 2CuSO4+4NaCN→Cu2(CN)2+2Na2SO4+(CN)2↑]

• [ 2Cu2S+4NaCN+2H2O+O2→Cu2(CN)2+Cu2(CNS)2+4NaOH]

Ngenxa yokusebenza kabusha okuqinile kwe-sodium cyanide enamaminerali ethusi amaningi, ngokuvamile, amagremu angu-2.3 kuya kwangu-3.4 e-cyanide ayadingeka ukuze kuncibilike igremu elingu-1 lethusi.

(3) Uma i-ore yegolide yoqobo iqukethe i-sphalerite noma i-smithsonite, zizophinde zihlangane ne-sodium cyanide ukwenza i-zinc cyanide ne-carbonates. Ukusabela kungokulandelayo:

• [ZnS+4NaCN→Na2[Zn(CN)4]+Na2S]

• [ ZnCO3+4NaCN→Na2Zn(CN)4+Na2CO3]

(4) Uma i-ore yegolide iqukethe i-arsenopyrite, i-mercury, i-selenium, i-tellurium, njll., izophinde isabele nge-sodium cyanide. Lapho umzimba we-ore uqukethe amatshe e-carbonaceous, ikakhulukazi lawo anothe nge-organic carbon, i-adsorption ye-cyanide iba namandla, okwenza i-cyanide leaching yegolide ibe nzima kakhulu.

3. Hydrolysis of Cyanides

Ngesixazululo, ama-cyanides zithola amazinga ahlukene e-hydrolysis kuye nge-pH, nenani le-hydrogen cyanide elikhiqizwayo lihlobene ne-alkalinity yesisombululo. Ukusabela kungamelwa kanje:

• [NaCN + H2O → NaOH + HCN↑]

• [CN⁻ + 2H2O → HCOO⁻ + NH3]

Ngemva kwe-hydrolysis, ingxenye ye-cyanide ikhiqiza i-hydrogen cyanide, kuyilapho enye ingxenye i-oxidatively hydrolyzed, kancane kancane ikhiqize i-formic acid ne-ammonia. Ku-100°C, i-CN⁻ ilahlekelwa ngu-50%, futhi ku-130°C, ilahlekelwa ngu-85%.

Enqubweni ye-cyanidation yokumbiwa kwegolide, i-hydrogen cyanide iyigesi enobuthi obukhulu. Uma ingaphathwa ngendlela efanele, ingaholela ekusetshenzisweni okwandisiwe kwe-NaCN, ukukhulisa izindleko zokukhiqiza, nokudangala ukungcoliswa kwemvelo, kanye nokubeka ubungozi bezempilo kubasebenzi. Inani le-HCN elikhiqizwayo liyahlukahluka nge-pH yesisombululo: ku-pH 10.5. kuphela i-6.1% ye-hydrogen cyanide ekhiqizwayo; ku-pH 10. inyuka ibe ngu-17%; ku-pH 9.5. ifinyelela ku-39.2%; kanye ne-pH 9.0. kungu-67.1%. Ngakho-ke, ezitshalweni zegolide ze-CIP (i-Carbon-in-Pulp), i-pH ngokuvamile ilungiswa ibe phakathi kuka-11 no-12 ukuze kulawulwe i-hydrolysis yama-cyanides.

4. I-oxidation ye-cyanide (CN-) nge-oxygen encibilikile (O2)

Ukuze kuthuthukiswe izinga lokuncibilika kwegolide, kokubili i-CN- ne-O2 kufanele ibandakanyeke ekuphenduleni. Ezingeni lokushisa legumbi nokucindezela, ukuncibilika okuphezulu komoyampilo kungu-8.2 mg/L. Ukwengezwa kwe-ejenti eqinile ye-oxidizing kungakhuphula ukuhlushwa komoya-mpilo esixazululweni, kusheshise kakhulu inqubo yokukhishwa. Nokho, isilinganiso somoya-mpilo ne-cyanide kufanele silingane; kungenjalo, izinga leaching lingancipha. I-oxygen encibilikisiwe ihlangana ne-cyanide yenze i-cyanate, ezinzile ezixazululweni ze-alkaline. Nokho, ku-pH engaphansi kuka-7. i-hydrolyzes ukuze ikhiqize i-ammonia ne-bicarbonate. Izibalo zokusabela zimi kanje:

• [1/2 O2 + CN– → (CNO)–]

• [(CNO)– + 2 H2O → HCO3– + NH3]

Ngakho-ke, lokhu kusabela kungase kuholele ekusetshenzisweni kwe-cyanide phakathi nezinqubo ze-leaching noma i-electrolysis.

5. I-Adsorption yeCyanide ngoClay

Ngesikhathi senqubo ye-cyanidation, i-iron sulfide ensimbi ikhiqiza i-iron hydroxide, kuyilapho ama-silicates e-ore enza i-colloidal silica endaweni ye-alkaline. Zombili lezi zinto zinamandla athile okukhangisa i-cyanide, okuholela ekulahlekeni kwe-cyanide kanye nensalela yokucwilisa.

6. Ukusetshenziswa kwe-cyanide ngezinye izinto

(1) Lapho i-slurry inyakaziswa futhi igcwaliswa ngomoya, i-CO2 izoqukethwe kwisixazululo. I-CO2 nayo izosabela nge-cyanide.

• [2NaCN+CO2+H2O→Na2CO3+2HCN↑]

(2) Amaminerali e-sulfide afana ne-pyrite ku-ore yasekuqaleni asabela nge-oxygen encibilikile (O2) ku-pulp ye-ore, futhi ama-sulfite aphumayo nama-sulfate nawo azosabela nge-cyanide.

• [FeS+2O2→FeSO4]

• [FeSO4+6NaCN→Na4Fe(CN)6+Na2SO4]

Inani elincane le-CaO noma i-Ca(OH)2 lingangezwa ngaphambi kokuvuzwa ukuze kuncishiswe i-asidi futhi kuvinjwe ukusabela okungenhla ukuthi kungenzeki.

Ekuphetheni

Okungenhla yizici eziyisi-6 zokusetshenziswa kwe-cyanide kunqubo yegolide ye-cyanidation. Ngaphezu kwe-cyanide edingekayo ekuhlakazweni okujwayelekile kwegolide, kuningi ukusetshenziswa okungabalulekile, njengokusabela kwethu namanye amaminerali ahlobene, i-self-hydrolysis, njll. 

Uma unanoma yimiphi imibuzo mayelana nokuqukethwe okungenhla, noma ufuna ukwazi, ungathintana nesevisi yamakhasimende aku-inthanethi noma uthumele umlayezo, sizokuthinta ngokushesha ngangokunokwenzeka!