Mvetsetsani ntchito ya sodium cyanide pakupanga golide wa ore leaching

M'dziko lovuta la Kukumba golide, kuchotsedwa kwa chitsulo chamtengo wapatalichi kuchokera ku miyala yake ndi njira yodzazidwa ndi kulondola kwa sayansi ndi luso lamakono. Mankhwala amodzi omwe amawonekera kwambiri munjira iyi ndi Sodium cyanide, chigawo chomwe chakhala chikugwiritsidwa ntchito ku migodi ya golide kwa zaka zopitirira zana. Nkhaniyi ikufotokoza za udindo wa Sodium Cyanide mu migodi golide, makamaka pa leaching ndondomeko, kuwunika ake mankhwala, ntchito, ndi miyeso anatengedwa kuonetsetsa ntchito yake motetezeka ndi zisathe.

The Chemical Reactivity ya Sodium Cyanide Ndi Golide

Sodium cyanide (NaCN) ndi yoyera, yolimba ya crystalline yomwe imasungunuka kwambiri m'madzi. Pankhani ya migodi ya golide, chinthu chake chofunikira kwambiri ndikutha kuchitapo kanthu ndi golide pamaso pa okosijeni kuti apange golide wosungunuka. Izi ndi maziko a Cyanidation ndondomeko, yomwe yakhala njira yayikulu yopangira golide kuyambira m'ma 1890.

The chemical equation for reaction between gold, sodium cyanide, mpweya, ndi madzi ndi motere:

4 Au + 8 NaCN + O₂ + 2 H₂O → 4 Na[Au(CN)₂] + 4 NaOH

Pochita izi, golidi amapangidwa ndi okosijeni ndikupanga zovuta ndi ayoni a cyanide. Mpweyawu umagwira ntchito ngati oxidizing, kumathandizira kusungunuka kwa golide. Zotsatira zake, sodium aurocyanide (Na[Au(CN)₂]), imasungunuka m'madzi, kulola golide kupatulidwa ndi matrix ore.

Kusungunuka kwapamwamba kwa sodium cyanide m'madzi ndikofunikira kwambiri kuti igwire bwino ntchito pa leaching. Imathandizira kufalikira mwachangu kwa ayoni a cyanide kudzera mu ore, ndikuwonjezera kulumikizana pakati pa reagent ndi tinthu tagolide. Izi, nawonso, timapitiriza mlingo wa zimene anachita ndi bwino wonse dzuwa m'zigawo golide.

Kugwiritsa Ntchito Njira Zosiyanasiyana za Golide Leaching

Kuchuluka kwa Leaching

Heap leaching ndi njira yomwe imagwiritsidwa ntchito kwambiri pokonza miyala yagolide yotsika. Akamachita zimenezi, miyalayo imaphwanyidwa n’kusanjika mu milu ikuluikulu ya chitsulo chosatha kulowa mkati. Mankhwala osungunula a sodium cyanide, omwe amakhala pakati pa 0.01% mpaka 0.05%, amawapopera pa muluwo. Njira ya cyanide imadutsa mu miyala, imachita ndi golide ndikuyisungunula. Njira yothetsera mimba, yomwe ili ndi golidi wosungunuka, imasonkhanitsidwa pansi pa mulu ndikukonzedwanso kuti itenge golide.

Mulu wa leaching ndi njira yotsika mtengo yochizira milingo yayikulu ya ore yotsika. Kugwiritsiridwa ntchito kwa sodium cyanide pochita izi kumapangitsa kuti golide atulutsidwe kuchokera ku miyala yomwe ikanakhala yopanda phindu kuti ipangidwe. Komabe, pamafunikanso kuyang'anira mosamala kuti zisawononge chilengedwe, chifukwa cyanide yankho limatha kulowa munthaka ndi madzi ozungulira ngati silili bwino.

Njira za Carbon-in-Leach (CIL) ndi Carbon-in-Pulp (CIP).

Njira za CIL ndi CIP nthawi zambiri zimagwiritsidwa ntchito pokonza golide wapamwamba kwambiri kapena kuyika golide. Munjira izi, miyalayi imayamba kukhala pansi kenako imasakanizidwa ndi yankho la sodium cyanide pamndandanda wa akasinja ovutitsidwa. Golide amasungunuka mu cyanide solution, kupanga golide wosungunuka.

Munjira ya CIL, kaboni wokhazikitsidwa amawonjezedwa mwachindunji ku akasinja a leach. Mpweya wa carbon umatulutsa golide, ndikulekanitsa bwino golide ku yankho. Mpweya wopakidwayo umachotsedwa m'matanki ndikukonzedwanso kuti atenge golide. Mu ndondomeko ya CIP, slurry yowonongeka imasiyanitsidwa poyamba ndi yankho, ndiyeno yankho limadutsa muzitsulo za carbon, kumene golide amakongoletsedwa pa carbon.

Njira zonse za CIL ndi CIP zimapereka mitengo yayitali yobwezeretsa golide ndipo ndizothandiza kwambiri potengera kugwiritsa ntchito reagent. Kugwiritsiridwa ntchito kwa sodium cyanide m'njirazi kumapangitsa kuti golide asungunuke mwapadera, kuchepetsa kuchotsedwa kwazitsulo zina zomwe zilipo mu miyalayi.

Zomwe Zimakhudza Kuchita Bwino kwa Sodium Cyanide mu Leaching

Kuchita bwino kwa sodium cyanide mu Kutulutsa golide ndondomeko imakhudzidwa ndi zinthu zingapo:

1. Makhalidwe a Ore: Mtundu ndi kapangidwe ka miyalayi imakhala ndi gawo lalikulu pakuwongolera. Ores okhala ndi golide wambiri komanso mineralogy yabwino, monga omwe ali ndi sulfide yochepa, amakonda kutulutsa golide wambiri. Kuonjezera apo, kukula kwa tinthu tating'onoting'ono kumakhudzanso malo omwe alipo kuti achite. Mwala wothira bwino nthawi zambiri umapangitsa kuti madzi azituluka bwino.

2. Kukhazikika kwa Cyanide: Kuchuluka kwa sodium cyanide mu leaching solution ndikofunikira kwambiri. Kuchuluka kwa cyanide kumatha kuwonjezera kuchuluka kwa kusungunuka kwa golide, komanso kumawonjezera mtengo wa reagent komanso chiwopsezo cha chilengedwe. Kuwongolera ndende ya cyanide ndikofunikira kuti muzitha kuyendetsa bwino ntchito yochotsa golide komanso malingaliro azachuma ndi chilengedwe.

3. Kupezeka kwa oxygen: Monga okosijeni amafunikira pakutulutsa golide, kupezeka kwake m'makina a leaching ndikofunikira. Aeration yokwanira kapena kuwonjezera ma oxidizing agents amatha kupititsa patsogolo ntchito ya leaching. Nthawi zina, ma okosijeni ena monga hydrogen peroxide kapena ozone angagwiritsidwe ntchito kuti azitha kuchita bwino.

4. pH ya Solution: pH ya yankho la leaching imakhudza kukhazikika kwa ayoni a cyanide komanso kusungunuka kwa golide. PH ya alkaline pang'ono, yomwe imakhala pakati pa 10 mpaka 11. ndi yabwino kwambiri pakupanga cyanidation. Kusintha pH kungathandize kupewa hydrolysis ya cyanide ndikuwonetsetsa kusungunuka kwa golide.

Kuganizira Zachilengedwe ndi Chitetezo

Sodium cyanide ndi chinthu chapoizoni kwambiri, ndipo kugwiritsidwa ntchito kwake mumigodi ya golidi kumafuna njira zokhazikika zachitetezo ndi chilengedwe:

Mphamvu Zachilengedwe

Chodetsa nkhaŵa chachikulu cha chilengedwe chokhudzana ndi kugwiritsa ntchito sodium cyanide mu migodi ya golide ndi kuthekera kwa kutulutsidwa kwa cyanide m'chilengedwe. Cyanide ikhoza kukhala poizoni ku zamoyo zam'madzi, zomera, ndi zinyama ngati ilowa m'madzi kapena m'nthaka. Pofuna kuchepetsa ngoziyi, ntchito za migodi zimagwiritsa ntchito njira zosiyanasiyana zoyendetsera chilengedwe, kuphatikizapo kugwiritsa ntchito madamu okhala ndi mizere kuti akhale ndi zitsulo zokhala ndi cyanide, kuthira madzi otayira kuti achepetse kuchuluka kwa cyanide, komanso kukhazikitsa mapologalamu owunika kuti azindikire kutayikira kapena kutayikira kulikonse.

Njira Zachitetezo kwa Ogwira Ntchito

Ogwira nawo ntchito yokumba golide, makamaka omwe amagwiritsa ntchito sodium cyanide, ali pachiwopsezo chokhudzidwa ndi mankhwala oopsawa. Pofuna kuonetsetsa kuti ali otetezeka, makampani opanga migodi amatsatira ndondomeko zotetezeka. Izi zikuphatikizapo kupatsa ogwira ntchito zipangizo zodzitetezera, monga magolovesi, magalasi, makina opumira, ndi kuwaphunzitsa kusamalira ndi kusunga bwino sodium cyanide. Kuonjezera apo, machitidwe otetezera ali m'malo kuti ateteze kutayika kwangozi komanso kuyankha mwamsanga pakagwa mwadzidzidzi.

Regulatory Framework

Kugwiritsiridwa ntchito kwa sodium cyanide mu migodi ya golide kumayendetsedwa ndi malamulo okhwima m'mayiko ambiri. Malamulo amayang'anira kupanga, kuyendetsa, kusunga, ndi kugwiritsa ntchito sodium cyanide, komanso kasamalidwe ka zinyalala zomwe zili ndi cyanide. Makampani opanga migodi akuyenera kutsatira malamulowa kuti awonetsetse kuti migodi yawo ikuyenda bwino komanso mokhazikika.

Njira zina za Sodium Cyanide

M'zaka zaposachedwa, pakhala chidwi chofuna kupanga njira zina zochotsera golide zomwe sizidalira kugwiritsa ntchito sodium cyanide. Zina mwa njira zomwe zingatheke ndi izi:

Thiosulfate Leaching

Thiosulfate leaching ndi njira yomwe imagwiritsa ntchito ayoni a thiosulfate, monga sodium thiosulfate, kuti asungunuke golide. Njirayi imapereka maubwino angapo kuposa cyanidation, kuphatikiza kutsika kawopsedwe, kuthamanga kwambiri kwa leaching, komanso kutha kukonza miyala yomwe imakhala yovuta kuchiza ndi cyanide. Komabe, thiosulfate leaching ilinso ndi zovuta zake, monga kufunikira kowongolera mosamalitsa mikhalidwe ya leaching komanso kukwera mtengo kwa reagent.

Bioleaching

Bioleaching ndi njira yachilengedwe yomwe imagwiritsa ntchito tizilombo toyambitsa matenda kuti tichotse golide ku miyala. Njirayi ndi yothandiza pa chilengedwe ndipo ingagwiritsidwe ntchito pochiza miyala yamtengo wapatali. Komabe, bioleaching ndi njira yapang'onopang'ono, ndipo kugwiritsa ntchito kwake kumangokhala kumitundu ina ya ore.

Ma Emerging Technologies ena

Palinso matekinoloje ena omwe akubwera, monga kugwiritsa ntchito zakumwa za ayoni ndi zamadzimadzi zowoneka bwino, zomwe zikuwonetsa kulonjeza kutulutsa golide. Matekinolojewa akadali pagawo loyesera, koma ali ndi kuthekera kopereka njira zogwirira ntchito komanso zachilengedwe zogwiritsa ntchito njira zachikhalidwe za cyanidation.

Kutsiliza

Sodium cyanide yakhala ikugwira ntchito yofunikira kwambiri pantchito yamigodi ya golide kwazaka zopitilira 100, zomwe zapangitsa kuti golide atuluke m'miyala yake. Kuthekera kwake kupanga ma soluble complexes ndi golide pamaso pa okosijeni kumapangitsa kuti ikhale yothandiza kwambiri pakupanga leaching. Komabe, kugwiritsa ntchito sodium cyanide kumabweranso ndi zovuta zazikulu zachilengedwe ndi chitetezo, zomwe zapangitsa kuti pakhale njira zoyendetsera bwino komanso kufufuza njira zina zochotsera golide.

Pamene migodi ya golide ikupitabe patsogolo, ndizotheka kuti tidzawona kutsindika kwakukulu pa chitukuko ndi kukhazikitsidwa kwa umisiri wokhazikika komanso wosamalira chilengedwe. Komabe, m'tsogolomu, sodium cyanide ikuyenera kukhalabe gawo lofunika kwambiri pakuchotsa golide, ngakhale kuwunika kowonjezereka komanso kukhazikitsa njira zowongolera zachilengedwe ndi chitetezo.