Ukusetyenziswa kwe-Sodium Cyanide kwi-Gold Extraction echazwe

Kwinkqubo yokukhupha igolide kwiikhompawundi zecyanide, Isodium cyanide ityiwa ngeendlela ezininzi. Isodium cyanide yeyona isetyenziswa ngokuqhelekileyo i-arhente evuzayo ekutsalweni kwegolide, kwaye ithiyori, kuphela 0.5 grams of Isodium cyanide iyadingeka ukukhupha i-1 gram yegolide. Nangona kunjalo, kwizityalo ezininzi ze-cyanidation zegolide, ukusetyenziswa kwe-cyanide kuphezulu kakhulu, ngokufuthi kudlula izibalo zethiyori ngamaxesha angama-50 ukuya kwi-100.

Izinto eziphambili ezinegalelo ekusetyenzisweni okuphezulu kwe-cyanide kwindawo inkqubo yegolide cyanidation ziquka:

1. Ukusetyenziswa kweCyanide kwiNkqubo yokuNcitshiswa kweGolide

Izityalo zecyanide bezisetyenziswa sodium cyanide ukunyibilikisa igolide kwintsimbi ekrwada ukuze kufunyanwe igolide kwileachati. Iimpendulo zekhemikhali ezibandakanyekayo zezi zilandelayo:

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

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

Ukusuka kwi-electrochemical reactions, kuyaziwa ukuba ukuchithwa kwe-1 gram yegolide kufuna ukusetyenziswa kwe-0.92 grams ye-sodium cyanide.

2. Ukusetyenziswa kwe-Cyanide kwiiNxulumano kunye neeNgxowa eziBasekileyo eziManyeneyo

(1) Ezinye iintsimbi zegolide zineeminerali ezinxulumeneyo ezifana nepyrite, magnetite, chalcopyrite, minerals yesulfate, hydroxides, kunye neeoxides. Ngethuba lesigaba sokutyumza, i-iron powder yenziwa, ehamba ngokuthe ngcembe kunye ne-sodium cyanide, ikhula ukusetyenziswa kwecyanide. Iimpendulo zezi zilandelayo:

• [FeS2+NaCN→FeS+NaCNS]

• [ Fe(OH)2+2NaCN→Fe(CN)2+2NaOH]

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

• [S+NaCN→NaCNS]

(2) Ukuba i-ore yegolide iqulethe iintlobo ezahlukeneyo zeeminerali zobhedu, nazo ziya kusabela kunye ne-sodium cyanide ukwenza i-copper cyanide complexes, idla i-cyanide kwinkqubo. Iimpendulo zezi zilandelayo:

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

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

Ngenxa ye-reactivity eqinile ye-sodium cyanide kunye namaminerali amaninzi obhedu, ngokuqhelekileyo, i-2.3 ukuya kwi-3.4 grams ye-cyanide iyadingeka ukuba ichithe i-1 gram yobhedu.

(3) Ukuba i-original ore yegolide iqulethe i-sphalerite okanye i-smithsonite, baya kusabela kwakhona nge-sodium cyanide ukwenza i-zinc cyanide kunye ne-carbonates. Iimpendulo zezi zilandelayo:

• [ ZnS+4NaCN→Na2[Zn(CN)4]+Na2S]

• [ ZnCO3+4NaCN→Na2Zn(CN)4+Na2CO3]

(4) Ukuba i-ore yegolide iqukethe i-arsenopyrite, i-mercury, i-selenium, i-tellurium, njl., Baya kusabela kwakhona nge-sodium cyanide. Xa umzimba we-ore uqulethe amatye e-carbonaceous, ngakumbi lawo atyebileyo kwi-organic carbon, i-adsorption ye-cyanide iba namandla, okwenza ukuba i-cyanide leaching yegolide ibe nzima ngakumbi.

3. Hydrolysis of Cyanides

Kwisisombululo, iicyanides zifumana amaqondo ahlukeneyo e-hydrolysis ngokuxhomekeke kwi-pH, kunye nesixa se-hydrogen cyanide esiveliswayo esinxulumene nealkalinity yesisombululo. Impendulo inokubonakaliswa ngolu hlobo lulandelayo:

• [NaCN + H2O → NaOH + HCN↑]

• [CN⁻ + 2H2O → HCOO⁻ + NH3]

Emva kwe-hydrolysis, inxalenye ye-cyanide ivelisa i-hydrogen cyanide, ngelixa enye inxalenye i-oxidatively hydrolyzed, ngokuthe ngcembe ivelisa i-asidi ye-formic kunye ne-ammonia. Kwi-100 ° C, i-CN⁻ ilahlekelwa yi-50%, kwaye kwi-130 ° C, ilahlekelwa yi-85%.

Kwinkqubo yecyanidation yokwembiwa kwegolide, ihydrogen cyanide yigesi eyityhefu kakhulu. Ukuba ayilawulwa ngokufanelekileyo, inokukhokelela ekusetyenzisweni okwandisiweyo kwe-NaCN, ukunyusa iindleko zemveliso, kunye nokubangela ungcoliseko lwendalo, kunye nokubeka umngcipheko wezempilo kubasebenzi. Isixa seHCN esiveliswayo siyahluka kunye ne-pH yesisombululo: kwi-pH 10.5. kuphela i-6.1% ye-hydrogen cyanide eveliswayo; kwi-pH 10. inyuka ukuya kwi-17%; kwi-pH 9.5. ifikelela kuma-39.2%; kunye ne-pH 9.0. yi 67.1%. Ke ngoko, kwizityalo zegolide zeCIP (iCarbon-in-Pulp), i-pH idla ngokuhlengahlengiswa phakathi kwe-11 kunye ne-12 ukulawula i-hydrolysis ye-cyanides.

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

Ukwandisa izinga lokuchithwa kwegolide, zombini i-CN- kunye ne-O2 kufuneka ibandakanyeke ekuphenduleni. Kwiqondo lokushisa kwegumbi kunye noxinzelelo, ubuninzi be-solubility ye-oxygen yi-8.2 mg / L. Ukongezwa kwe-agent eqinile ye-oxidizing kunokunyusa ukuxinwa kwe-oksijini kwisisombululo, ngokukhawuleza ukukhawuleza inkqubo yokucoca. Nangona kunjalo, umlinganiselo weoksijini kwi-cyanide kufuneka ulinganiswe; kungenjalo, izinga leaching lingahla. Ioksijini enyibilikisiweyo idibana ne-cyanide yenze i-cyanate, ezinzileyo kwizisombululo zealkaline. Nangona kunjalo, kwi-pH engaphantsi kwe-7. i-hydrolyzes ukuvelisa i-ammonia kunye ne-bicarbonate. Ii-equations zokusabela ngolu hlobo lulandelayo:

• [1/2 O2 + CN– → (CNO)–]

• [(CNO)– + 2 H2O → HCO3– + NH3]

Ngoko ke, le mpendulo inokukhokelela ekusetyenzisweni kwe-cyanide ngexesha le-leaching okanye iinkqubo ze-electrolysis.

5. I-Adsorption yeCyanide nguDongo

Ngexesha lenkqubo ye-cyanidation, i-iron sulfide kwi-ore yenza i-iron hydroxide, ngelixa i-silicates kwi-ore ifom ye-colloidal silica kwi-alkaline medium. Zombini ezi zinto zinomthamo othile wokubhengeza icyanide, ekhokelela ekulahlekeni kwecyanide kunye nentsalela yokukhupha.

6. Ukusetyenziswa kwe-cyanide ngezinye izinto

(1) Xa i-slurry ishukunyiswa kwaye izaliswe ngumoya, i-CO2 iya kuqukwa kwisisombululo. I-CO2 nayo iya kusabela kunye ne-cyanide.

• [2NaCN+CO2+H2O→Na2CO3+2HCN↑]

(2) Iiminerali ze-sulfide ezifana ne-pyrite kwi-original ore isabela nge-oksijini echithiweyo (O2) kwi-pulp ye-ore, kunye ne-sulfites kunye ne-sulfates ezibangelwayo nazo ziya kusabela nge-cyanide.

• [FeS+2O2→FeSO4]

• [FeSO4+6NaCN→Na4Fe(CN)6+Na2SO4]

Inani elincinci le-CaO okanye i-Ca (OH) i-2 inokudibaniswa ngaphambi kokuba i-leaching i-neutralize i-asidi kunye nokukhusela ukusabela okungentla ukuba kwenzeke.

ukuququmbela

Oku ngasentla yimiba ye-6 yokusetyenziswa kwe-cyanide kwinkqubo ye-cyanidation yegolide. Ukongeza kwi-cyanide efunekayo ukuchithwa okuqhelekileyo kwegolide, zininzi izinto ezingabalulekanga zokusetyenziswa, ezifana nokusabela kwethu kunye nezinye iiminerali ezinxulumene nazo, i-self-hydrolysis, njl. 

Ukuba unayo nayiphi na imibuzo malunga nalo mxholo ungasentla, okanye ufuna ukwazi i-, ungabonisana nenkonzo yabathengi kwi-intanethi okanye uthumele umyalezo, siya kuqhagamshelana nawe ngokukhawuleza!