Direct Electrowinning of Gold kuchokera ku Cyanide Solution

Introduction

Kwa nthawi yayitali, kusakaniza golide ndi cyanide kwakhala njira yayikulu yopezera golide kuchokera ku miyala. Pambuyo pa njira yochotsera golide kuchokera ku cyanide , golideyo amapezeka mu yankho la cyanide , lotchedwa njira ya pregnant leach. Mwachikhalidwe, njira monga Carbon adsorption (monga njira ya Carbon-in-Column - CIC) ndi zinc cementation (njira ya Merrill Crowe) zakhala zikugwiritsidwa ntchito pobwezeretsa golide kuchokera ku yankholi. Komabe, kupeza golide mwachindunji kuchokera ku njira za cyanide kwakhala njira ina yabwino, yopereka zabwino zingapo pankhani ya magwiridwe antchito, mtengo, komanso kuwononga chilengedwe.

Mfundo ya Direct Electrowinning

Kupambana ma electrode mwachindunji ndi njira yamagetsi. Pankhani yochotsa golide kuchokera ku mayankho a cyanide, pamene magetsi amagetsi amadutsa mu yankho la cyanide lomwe lili ndi golide mu mawonekedwe a aurocyanide complexes ( Au(CN)_2^- ), zotsatirazi zimachitika pa ma electrode:

• Pa cathode : Au(CN)_2^- + e^- \rightarrow Au + 2CN^-

Ma ion a golide mu aurocyanide complex amapeza ma elekitironi ndipo amayikidwa ngati golide wachitsulo pamtunda wa cathode.

• Pa anode : Kutengera ndi momwe zinthu zilili, kusungunuka kwa madzi kapena kusungunuka kwa mitundu ina mu yankho kungachitike. Mwachitsanzo, 2H_2O \rightarrow O_2 + 4H^+ + 4e^-

Ubwino wa Direct Electrowinning

1. Kuphweka : Poyerekeza ndi njira zambiri monga kulowetsedwa kwa kaboni kutsatiridwa ndi kuchotsedwa ndi kuchotsedwa kwa electro (pa nkhani ya CIC), kuchotsedwa kwa electro mwachindunji kumachepetsa kuchuluka kwa ntchito za unit. Izi zimapangitsa kuti ntchito yonse ikhale yosavuta, zomwe zimapangitsa kuti ikhale yosavuta kuyigwiritsa ntchito ndikusamalira.

2. Kugwiritsa Ntchito Mtengo : Ndi njira zochepa zogwirira ntchito, pali kuthekera kochepetsa ndalama zogwirira ntchito komanso ndalama zogwirira ntchito. Palibe chifukwa choyika ndalama m'malo akuluakulu okonzanso mpweya wa kaboni (monga momwe zilili ndi CIC) kapena kugula ufa wambiri wa zinc (monga momwe zilili ndi njira ya Merrill Crowe).

3. Chogulitsa Choyera Kwambiri : Kuyika kwa golide mwachindunji kungapangitse kuti golide woyera kwambiri asungidwe pa cathode. Izi zitha kuchepetsa kufunikira kwa njira zambiri zoyeretsera pambuyo pake, zomwe zingapulumutse ndalama zambiri.

4. Ubwino wa Zachilengedwe : Pochotsa kugwiritsa ntchito zinc mu njira ya Merrill Crowe, pamakhala kuchepa kwa kupanga zinyalala zokhala ndi zinc. Kuphatikiza apo, kuphweka kwa njirayi kungayambitse kuchepa kwa kugwiritsa ntchito mankhwala onse komanso kupanga zinyalala.

Malingaliro a Njira

1. Kuchuluka kwa golide mu yankho la cyanide ndi chinthu chofunikira kwambiri. Ngakhale kuti electrowinning mwachindunji ingagwiritsidwe ntchito pa mayankho okhala ndi kuchuluka kwa golide kosiyanasiyana, kuchuluka kwakukulu nthawi zambiri kumapangitsa kuti pakhale kuchuluka kwa golide mwachangu. Komabe, kuchuluka kwa golide kochuluka kwambiri kungafunike mapangidwe apadera a ma electrode kuti zitsimikizire kuti malo osungiramo zinthu ndi ofanana.

2. Zipangizo za Electrode : Kusankha zipangizo za electrode n'kofunika. Ubweya wachitsulo wosapanga dzimbiri nthawi zambiri umagwiritsidwa ntchito ngati zinthu za cathode chifukwa cha malo ake okwera, zomwe zimathandiza kuti golide azisungidwa bwino. Pa anode, zinthu zomwe sizingawonongeke ndi dzimbiri mu yankho la cyanide, monga ma anode okhazikika (DSA), ndi zomwe zimakondedwa.

3. pH ndi Kutentha : pH ya yankho la cyanide iyenera kulamulidwa mosamala. pH ya alkaline pang'ono nthawi zambiri imasungidwa kuti ipewe kuwonongeka kwa cyanide. Kutentha kwa yankho kungakhudzenso kuchuluka kwa magetsi, ndipo kutentha kwakukulu nthawi zambiri kumawonjezera liwiro la reaction komanso kungayambitse chiopsezo cha kuwonongeka kwa cyanide.

Njira ikuyenda

1. Kukonzekera kwa Yankho : Yankho la cyanide leach lomwe lili ndi pakati lomwe limachotsedwa mu heap leaching kapena njira zina zochotsera cyanidation limayamba layamba kuchitidwa chithandizo chisanachitike. Izi zitha kuphatikizapo kusefedwa kuti zichotse zinthu zolimba zomwe zimapachikidwa, chifukwa izi zitha kusokoneza njira yopezera magetsi ndikupangitsa kuti ma electrode achepe pakati pa ma electrode.

2. Selo Yopambana ndi Magetsi : Yankho lomwe lakonzedwa kale limalowetsedwa mu selo yopambana ndi Magetsi. Seloyo imakhala ndi anode ndi cathode. Pamene magetsi akugwiritsidwa ntchito, golide amayamba kuyikidwa pa cathode.

3. Kubwezeretsa Golide : Golide wokwanira akayikidwa pa cathode, cathode imachotsedwa mu selo. Golideyo amatha kuchotsedwa mu cathode mwanjira yamakina kapena mankhwala, kutengera mtundu wa zinthu za cathode. Golide wochotsedwayo amayengedwanso kuti apeze golide woyera kwambiri.

Zovuta ndi Chiyembekezo Chatsogolo

1. Kasamalidwe ka Cyanide : Ngakhale kuti kuponya mwachindunji kwa magetsi kumapereka ubwino, kugwiritsa ntchito cyanide pochotsa golide kumaikabe zoopsa zachilengedwe komanso chitetezo. Kafukufuku wamtsogolo angayang'ane kwambiri pakuphatikiza kuponya mwachindunji kwa magetsi ndi njira zina zochotsera poizoni.

2. Kugwiritsa Ntchito Mphamvu : Njira yopezera mphamvu zamagetsi imafuna mphamvu zamagetsi zambiri. Kupanga zipangizo zamagetsi zogwiritsa ntchito mphamvu zambiri komanso mapangidwe a maselo ndi gawo lofufuza mwachangu.

3. Kukula : Monga momwe zilili ndi ukadaulo uliwonse watsopano, kukulitsa luso lamagetsi mwachindunji kuchokera ku ntchito za labotale mpaka mafakitale kuyenera kukonzedwa bwino kuti zitsimikizire kuti magwiridwe antchito ndi mtengo wake ndi wogwirizana.

Kupeza golide mwachindunji kuchokera ku njira zothetsera cyanide kukuwonetsa kupita patsogolo kwakukulu kwaukadaulo mumakampani opanga migodi ya golide. Ndi kafukufuku wowonjezereka komanso chitukuko chothana ndi mavuto omwe alipo, ikhoza kukhala njira yodziwika bwino yopezera golide posachedwa.