I-Cyanide Gold Extraction Inqubo Yokuhlanza Amanzi Angcolile

Okwamanje, i i-cyanide indlela yokukhipha igolide ingenye yezinqubo ezivuthiwe zokuncibilikisa igolide eChina. Isebenzisa isixazululo se-cyanide ukukhipha igolide ku-ore, enezinga eliphezulu lokululama, ukuguquguquka okuqinile kuzakhiwo ze-ore, kanye nekhono lokukhiqiza igolide esizeni. Kusukela ekusetshenzisweni kokuqala kwesisombululo se-cyanide ukuze kukhishwe igolide kusuka ezinsimbi ngo-1887. le ndlela iye yasetshenziswa kabanzi kuze kube manje. Kodwa-ke, ukukhishwa kwegolide kwe-cyanide kukhiqiza inani elikhulu lezinto ezinobuthi neziyingozi, kube usongo olukhulu endaweni ezungezile nakubantu. Ngakho-ke, ukuze kuncishiswe umonakalo, kuyadingeka ukutadisha izindlela zokwelashwa kwamanzi angcolile e-cyanide gold extraction. Inani elikhulu labacwaningi lifingqe izindlela zokwelapha, izimiso zamakhemikhali, kanye nezitayela zokuthuthukiswa kwe-cyanide - equkethe amanzi angcolile, kodwa iningi labo lixoxa ngendlela eyodwa noma ezimbili kuphela. Ngakho-ke, lesi sihloko senza ukuhlaziya okuningiliziwe kwezindlela ezihlukahlukene zokwelashwa kwamanzi angcolile e-cyanide ekhipha igolide esetshenziswa embonini, iqhathanisa izinzuzo, ububi, nezimo zokusetshenziswa zendlela ngayinye, enokubaluleka okuthile okuyisiqondiso kwezinhlelo zokusebenza ezifanayo ekukhiqizeni kwangempela.

I. Imithombo Nezingozi Ze-Cyanide Gold Extraction Amanzi Angcolile

Umgomo oyinhloko wokukhishwa kwegolide le-cyanide ukuthi endaweni ye-aerobic, i-sodium cyanide iphendula negolide ukuze yakhe ama-complex egolide, abese encibilika. Ngemva kwalokho, igolide lingakhishwa ngokucebisa ngokusebenzisa i-activated I-Carbon ukumuncwa noma ukushintshwa yi-zinc powder evela ku-gold cyanide. Ngesikhathi esifanayo, ezinye izinsimbi ezisindayo njengesiliva, ithusi, kanye ne-zinc nazo zakha ama-complexes futhi zincibilike.

The ama-cyanides esetshenziswa ekuphenduleni kanye nezakhiwo ezikhiqizwayo zonke ziyizinto ezinobuthi neziyingozi. I-sodium cyanide igaywa kalula i-hydrolyze futhi iyisithako esinobuthi esiseSigabeni 1, esinomthamo obulalayo ongu-0.10g. Nini Ama-cyanides Ukuvuza emanzini, kuyingozi kakhulu ezintweni eziphila emanzini, futhi kuzodala ingozi enkulu kubantu nasezindaweni ezizungezile. Ngakho-ke, ukwelashwa kwamanzi angcolile e-cyanide gold extraction kubaluleke kakhulu.

II. Izindlela Zokwelapha Eziyinhloko Zokukhipha Igolide Le-Cyanide Amanzi Angcolile

Indlela ye-Alkaline Chlorination

Indlela ye-alkaline chlorination okwamanje ingenye yezindlela ezivame ukusetshenziswa kakhulu zokwelapha i-cyanide - equkethe amanzi angcolile aphuma ekukhishweni kwegolide le-cyanide. Ikakhulukazi isebenzisa ama-oxidant asuselwa ku-chlorine ukuze i-cyanide ikhiphe emanzini angcolile ngaphansi kwezimo ze-alkaline, iwaguqule abe izinto ezingezona ezinobuthi. Inqubo yokuphulwa kwe-cyanide ye-alkaline chlorination ihlukaniswe izigaba ezimbili:

Isigaba sokuqala siwukwenza i-cyanide ibe yi-cyanate, ebizwa ngokuthi "i-oxidation engaphelele". I-CN⁻ isabela nge-OCl⁻ ukwenza i-CNCl kuqala, bese i-hydrolyzes ibe yi-CNO⁻. Kumele kuqashelwe ukuthi i-CNCl iguquguquka kakhulu futhi inobuthi ngaphansi kwezimo ze-acidic. Ngakho-ke, ngesikhathi sokusebenza, inani le-pH kufanele lilawulwe ngokuqinile ukuze libe sesimweni se-alkaline.

Isigaba sesibili ukuqhubekisela phambili i-oxidize i-cyanate ku-carbon dioxide ne-nitrogen, ebizwa ngokuthi "isigaba se-oxidation esiphelele". Ngesikhathi senqubo yokuphulwa kwe-cyanide, inani le-pH linomthelela omkhulu ekuphenduleni kwe-oxidation. Inani le-pH le-oxidation yesiteji sokuqala kufanele lilawulwe ku-10 - 11. futhi isikhathi sokusabela siyimizuzu eyi-10 - 15. Inani le-pH ye-oxidation yesiteji sesibili kufanele ilawulwe ku-6.5 - 7.0. futhi isikhathi sokuphendula siyimizuzu eyi-10 - 15.

Imayini ethile isebenzisa indlela ye-alkaline chlorination ukwelapha i-supernatant ye-cyanide tail slurry (ngokuqukethwe kwe-cyanide engu-200mg/L) kanye namanzi agelezayo asuka ethangini le-sedimentation (nokuqukethwe kwe-cyanide okungu-5mg/L). Inani le-pH lilawulwa ku-10 - 11. futhi i-bleaching powder yengezwa ngesilinganiso sama-35 - 40 izikhathi zokuqukethwe kwe-cyanide ukuze kuxutshwe futhi kuxutshwe. Ngemuva kokufakwa kwe-sedimentation ku-thickener, inani eliphelele le-cyanide lingancishiswa libe ngu-0.1mg/L.

Indlela ye-alkaline chlorination iyindlela evame ukusetshenziswa kakhulu yokwelapha i-cyanide - equkethe amanzi angcolile, futhi impushana emhlophe iyona esetshenziswa kakhulu i-chlorine - oxidant esekelwe. Le ndlela ilungele ukwelapha amanzi angcolile e-cyanide ekhishwa ngegolide ngokugxila okuphezulu noma okuphansi. Ingase futhi isuse i-thiocyanate ne-cyanide - equkethe izakhiwo (ngaphandle kwe-ferrocyanide complexes). I-medicament itholakala kabanzi, izinsalela zemfucuza ezikhiqiziwe kulula ukuzihluza, futhi ukusebenza kulula. Kodwa-ke, indawo yokusebenza inokhahlo uma kusetshenziswa impushana emhlophe ukugeza amanzi angcolile. Manje amanye amabhizinisi asebenzisa uketshezi olumhlophe noma i-chlorine dioxide esikhundleni salokho, okuthuthukisa indawo yokusebenza ngezinga elithile. Kodwa amagesi anobuthi akhiqizwa phakathi nenqubo yokusabela, futhi inokugqwala okukhulu kwemishini. Izindleko zomuthi kanye nezindleko zokuwulungisa ziphezulu uma kuqhathaniswa.

Indlela Yokuhlanganisa Usawoti Ewumbi

Indlela yokuhlanganisa usawoti oyinsimbi iyindlela yokwelapha yokukhipha amanzi angcolile e-cyanide evele eminyakeni yamuva nje. Ngokulawula ukusabela kwevelu ye-pH ku-7 - 8. Ama-ion ayoni asabela nge-cyanide yamahhala nezinye izakhiwo ze-cyanide emanzini angcolile e-cyanide ekhishwa igolide ukuze enze imvula.

Ukuhlola kubonise ukuthi ngokuvamile, ukungeza i-ferrous sulfate kuphela ukwelapha amanzi angcolile e-cyanide ekhishwa igolide akukwazi ukwenza amanzi angcolile ahlangabezane nezindinganiso zokukhishwa. Ngakho-ke, i-oxidant evamile idinga ukungezwa emanzini angcolile ahlanzekile ukuze kukhishwe i-cyanide ejulile. Uma nje izimo zilawulwa kahle, i-oxidant ingafakwa ngokuqondile ukuze iphathwe ngaphandle kokuhlukanisa i-precipitate, futhi izinga lokukhipha lingafinyelelwa. Lokhu kunokubaluleka okuhle uma kuqhathaniswa nendlela yendabuko yokuhlukanisa kuqala bese kuba ukwelashwa.

Isincibilikisi esithile segolide sisebenzisa indlela ye-sodium sulfide - ferrous sulfate ukwelapha i-cyanide - uketshezi olubi. I-influent inokuqukethwe kwe-cyanide okungu-2500mg/L. Ngemuva kokwelashwa, ukungcola kunokuqukethwe kwe-cyanide okungaphansi kuka-20mg/L, nesilinganiso sokukhipha esingu-99.2%, okubonisa imiphumela emangalisayo. Ukujula okulandelayo - ukwelashwa kusebenzisa i-sodium metabisulfite - indlela yomoya ukunciphisa isamba se-cyanide sibe ngaphansi kuka-0.4mg/L.

Indlela yokuxuba usawoti okusansimbi iyindlela yokwelapha esanda kuvela, esetshenziswa kakhulu ukwelapha i-cyanide ephezulu - equkethe amanzi angcolile. Inqubo yayo ilula, ukutshalwa kwezimali ngesikhathi esisodwa kuncane, kulula ukuyisebenzisa, umuthi (ikakhulukazi i-ferrous sulfate) utholakala kabanzi, awubizi, futhi kulula ukuwusebenzisa. Nokho, ngenxa yokuthi i-ferrous sulfate solution ine-asidi, lapho ixutshwa namanzi angcolile e-cyanide ekhipha igolide, indawo yendawo iba ne-asidi, futhi kunethuba lokukhiqiza igesi ye-hydrogen cyanide. Ngaphezu kwalokho, ayikwazi ukususa i-thiocyanate, futhi amanzi angcolile ahlanzekile asadinga ukwelashwa okujulile ukuze ahlangabezane nezindinganiso zokukhishwa.

I-Sodium Metabisulfite - Indlela Yomoya

I-sodium metabisulfite - indlela yomoya ithuthukiswa kusuka ku-sulphur dioxide - indlela yomoya. Ikakhulukazi isebenzisa umthelela we-synergistic we-sodium metabisulfite nomoya kuma-cyanides emanzini angcolile ngaphakathi kwebanga elithile le-pH, nomthelela we-catalytic wama-ion ethusi, ukuze kufakwe i-CN⁻ ku-CNO⁻.

Uma okuqukethwe kwe-cyanide ku-cyanide - equkethe amanzi angcolile kuphezulu, ukwelashwa kwangaphambili kungenziwa kuqala ukuze kuncishiswe inani eliphelele le-cyanide libe ngaphansi kuka-100mg/L. Khona-ke, i-metabisulfite ye-sodium ne-copper sulfate yengezwa, kwethulwa umoya owanele, futhi inani le-pH liyalawulwa (ngokuvamile lilawulwa ku-7 - 8), ukuze i-cyanide ifakwe i-cyanide ibe yi-cyanate, bese i-hydrolyzed ukuze yakhe i-bicarbonate ions ne-ammonia.

I-sodium metabisulfite - indlela yomoya ilungele ukwelapha amanzi angcolile e-cyanide ekhishwa ngegolide eliphansi. Isilinganiso somuthi sincane, amandla okusebenza aphansi, kodwa ukutshalwa kwezimali kwangaphambili kukhulu, futhi amathuluzi afana nama-blowers adinga ukwengezwa. Izidingo zezinkomba zenqubo ziqinile, futhi ukulawula inani le-pH kubaluleke kakhulu. I-Copper sulfate nayo idinga ukungezwa njenge-catalyst. Isikhathi sokuphendula side. Uma ukwelashwa kungalungile, kuzokwenziwa inani elikhulu lama-ammonium ion, futhi i-slag ekhiqiziwe akulula ukuyihlunga. Kunenani elincane legesi ye-ammonia elakhiwe esizeni, futhi alinawo umthelela ekukhipheni ama-thiocyanides.

I-Hydrogen Peroxide Oxidation Indlela

Indlela ye-hydrogen peroxide oxidation iwukwenza i-cyanides ibe yi-CNO⁻ ngaphansi kwezimo zezinga lokushisa elivamile, i-alkaline (pH = 10 - 11), nge-Cu²⁺ njengesisusa, bese iwafaka emanzini angenabuthi. I-cyanides eyinkimbinkimbi (i-complexes ye-Cu, i-Zn, i-Pb, i-Ni, i-Cd) nayo ihlukaniswe ngenxa yokubhujiswa kwama-cyanides kuwo. Ama-ion e-Ferrocyanide namanye ama-ion ensimbi esindayo akha usawoti oyinkimbinkimbi we-ferrocyanide futhi ayasuswa. Okokugcina, inani eliphelele le-cyanide emanzini angcolile ahlanzekile lingancishiswa libe ngaphansi kuka-0.5mg/L.

Le ndlela ilungele ukwelapha i-low-concentration cyanide - equkethe amanzi angcolile. Imishini yokwelapha ye-hydrogen peroxide ilula futhi kulula ukuyifinyelela ukulawula okuzenzakalelayo. Nokho, i-cyanate ekhiqiziwe idinga ukuhlala isikhathi esithile ukuze ibole ibe yi-CO₂ ne-NH₃. Okubi ukuthi ukusebenzisa ithusi njenge-catalyst kungabangela ithusi emanzini akhishiwe ukuba lidlule izinga, izindleko zempahla eluhlaza ziphezulu uma kuqhathaniswa, i-thiocyanides ayikwazi ukufakwa i-oxidized, futhi ama-ion ammonium akhiqizwa. Eqinisweni, amanzi angcolile asenobuthi obuthile. Ngaphezu kwalokho, njengoba i-hydrogen peroxide iyi-oxidant, inokugqwala okukhulu, futhi kunobunzima obuthile nezingozi zokuhamba nokusetshenziswa.

Indlela ye-Acidification

Uma usebenzisa indlela ye-acidification ukwelapha i-cyanide - uketshezi olungenamandla, indlela yokusabela kwayo iyinkimbinkimbi, ikakhulukazi ihlanganisa izinqubo ezintathu: inqubo ye-acidification ye-cyanide - equkethe amanzi angcolile, inqubo yokuhlubula nokumuncwa kwegesi ye-HCN, kanye nenqubo yokunciphisa uketshezi oluhlutshiwe.

(1) Ukusabela kwe-Acidification: I-cyanide - uketshezi olumpofu lufakwa i-asidi futhi luhlanzwe nge-asidi. I-cyanides eyinkimbinkimbi oketshezini olumpofu izokwakha amanzi angancibiliki njenge-CuCN, i-CuSCN, ne-Zn₂Fe(CN)₆ futhi isuswe, ngesikhathi esifanayo, i-hydrogen cyanide iyakhiqizwa.

(2) Ukuguquguquka nokumuncwa: Uketshezi olungeluhle lufudunyezwa ngaphambi kokuthi lufike ku-30 ​​℃ ngaphambi kokwenziwa kwe-asidi. Njengoba indawo yokubilisa ye-HCN ingu-26.5℃ kuphela, iyaguquguquka ngokwedlulele. Ngakho-ke, umbhoshongo ogcwele usetshenziswa njengenqwaba - imishini yokudlulisa ukuxhumana phakathi kwegesi - uketshezi lwesibili - isigaba sendlela ye-acidification, okulula ukufeza ukukhumula nokumuncwa kwe-HCN.

(3) Ukusabela kokungathathi hlangothi: I-lime noma i-alkali ewuketshezi isetshenziselwa ukwenza i-asidi ingasebenzi - uketshezi oluyinsalela oluhlutshiwe. Ama-molecule e-HCN asele esixazululweni azoguqulwa abe yifomu le-CN⁻. Indlela ye-acidification ingalulama I-Sodium Cyanide kusuka ku-cyanide - equkethe amanzi angcolile futhi ibone ukutholwa kwezinsiza. Kodwa-ke, inezidingo eziphakeme zokuvalwa kwemishini, ukutshalwa kwezimali kwangaphambili okukhulu, kudinga amakhono okusebenza asezingeni eliphezulu, kanti nokugcinwa kwemishini kunzima. Kukhona nezingozi ezithile zokuphepha. Amanzi angcolile akhiqizwa ngemva kokululama asadinga ukwelashwa okujulile ukuze ahlangabezane nezindinganiso zokukhishwa.

Indlela ye-Electrolysis

Indlela ye-electrolysis isebenzisa ukusabela kwe-electrochemical redox ukucekela phansi ama-cyanides emanzini angcolile. Ngesikhathi se-ion electrolysis, ama-cyanides alahlekelwa ama-electron ku-anode futhi afakwe i-oxidized ku-cyanate, carbonate, nitrogen, noma ammonium. I-Cyanate iphinde ifakwe i-CO₂ ne-H₂O. Ukusabela okuyinhloko yilezi:

CN⁻ + 2OH⁻ - 2e → CNO⁻ + H₂O (24)

2CN⁻ + 4OH⁻ - 6e → 2CO₂ + N₂ + 2H₂O (25)

Ukuhlolwa kwe-electrolysis kusetshenziswa i-ceramic eyenziwe ngokwayo - based lead lead electrode electrode rod kanye ne-stainless - steel cathode plate kufakazele ukuthi ngokusebenzisa indlela ye-electrolysis ukwelapha i-cyanide - equkethe amanzi angcolile, ngemva kwamahora angu-2 e-electrolysis, ukugxila kwe-CN⁻ kungehliswa ukusuka ku-385mg/L kuye ku-58mg/L, futhi ukugxiliswa kwe-Cu²⁺ kusuka ku-450mg/L kuya ku-48mg/L kungancipha. Ngaphezu kwalokho, i-Hunan Zhongnan Gold Smelter isebenzisa indlela ye-electrochemical ukwelapha amanzi angcolile e-cyanide ekhishwa igolide, enganciphisa ingqikithi ye-cyanide isuka ku-4g/L iye ku-0.8g/L. Umehluko kulokhu okungenhla ukuthi kokubili amapuleti e-anode ne-cathode enziwe ngamapuleti ensimbi. Phakathi nenqubo yokusebenza, akugcini nje ukudliwa amandla kagesi, kodwa futhi amapuleti ensimbi ayadliwa.

Indlela ye-electrolysis isetshenziswa kakhulu ukwelapha i-cyanide ephezulu - equkethe amanzi angcolile. Imishini ithatha indawo encane, inqubo ilula futhi kulula ukuyilawula, kodwa idla inani elikhulu lamandla kagesi, futhi izindleko zokusebenza ziphakeme kunendlela ye-alkaline chlorination. Izinga lokususwa kwe-cyanide liyisilinganiso, futhi alinawo umthelela ekukhipheni ama-cyanide complexes.

Njengamanje, phakathi kwezindlela zokwelashwa zamanzi angcolile e-cyanide gold extraction, indlela ye-alkaline chlorination, indlela ye-acidification, kanye ne-sodium metabisulfite - indlela yomoya isetshenziswa kabanzi. Indlela ye-electrolysis kanye ne-ferrous salt complexation method izindlela ezintsha ezisanda kuvela ezisetshenziswe ngempumelelo ekwelashweni kwezimboni. Indlela ye-hydrogen peroxide oxidation ngokuyinhloko iyindlela yokwelapha ephuthumayo. Ziningi ezinye izindlela zokwelapha zokwelapha amanzi angcolile e-cyanide yokukhipha igolide, njengendlela yokuhlanza yemvelo, indlela yezinto eziphilayo, indlela yokuhlukanisa ulwelwesi, indlela ye-ion - exchange, njll. Nokho, njengezicelo zezimboni, zonke zinemikhawulo ethile futhi zisadinga ukuthuthukiswa okuqhubekayo.