Sodium cyanide Leaching in Gold Mining

Introduction

Kukopa kwa Golide ndi Udindo wa Cyanide Leaching

Golide wakopa anthu kwa zaka zikwi zambiri, kukongola kwake ndi kusoweka kwake kumapangitsa kukhala chizindikiro cha chuma, mphamvu, ndi kukongola m'zikhalidwe zosiyanasiyana. Kuchokera ku zinthu zakale za golide zakale za ku Egypt kupita ku malo osungira golide amakono omwe amasungidwa ndi mabanki apakati, kufunikira kwa golide pachuma chapadziko lonse lapansi ndi chikhalidwe sikungatsutsidwe. Imagwira ntchito ngati sitolo yamtengo wapatali, mpanda wolimbana ndi kusatsimikizika kwachuma, komanso gawo lofunikira pazambiri zodzikongoletsera, zamagetsi, ndi mafakitale apamlengalenga.

Mu ufumu wa mgodi wagolide, cyanide leaching yawoneka ngati njira yayikulu yochotsera. Chiyambireni kukhazikitsidwa kwa mafakitale kumapeto kwa zaka za m'ma 19, cyanide leaching yasintha kwambiri migodi ya golide, zomwe zapangitsa kuti golide atulutsidwe kuchokera ku miyala yamtengo wapatali yomwe poyamba inali yopanda ndalama kuti ipangidwe. Njirayi imagwiritsa ntchito mankhwala apadera a cyanide kuti asungunuke golide kuchokera ku ore, kupanga golide wosungunuka wa cyanide complexes omwe amatha kupatukana ndi kuyeretsedwa mosavuta.

Chemistry Kumbuyo kwa Cyanide Leaching

Kuchitanso kwa Cyanide ndi Golide

Njira ya cyanide leaching imatengera kukhazikika kwapadera kwamankhwala pakati pa ma cyanide ion ndi golide. Liti Sodium cyanide (NaCN) imasungunuka m'madzi, imasiyanitsidwa kukhala sodium ions (Na⁺) ndi cyanide ions (CN⁻). Ma cyanide ions awa amagwira ntchito kwambiri ku golidi, ndipo pamaso pa okosijeni, amayamba kuchitapo kanthu movutikira.

The chemical equation for reaction between gold, Sodium Cyanide, mpweya, ndi madzi ndi motere:

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

Pochita izi, maatomu agolide omwe ali mu ore amakhudzidwa ndi ma cyanide ions kupanga chosungunuka chosungunuka, sodium dicyanoaurate (Na[Au(CN)₂]). Mpweya womwe umapezeka mu yankho umakhala ngati wothandizira oxidizing, womwe umathandizira zomwe zimachitika popereka ma elekitironi ofunikira kuti apange golide - cyanide complex. Mamolekyu amadzi amathandizanso pakuchitapo kanthu, kutenga nawo gawo pakupanga zovuta komanso zopangira, sodium hydroxide (NaOH).

This reaction is a redox process. Gold is oxidized from its elemental state (Au⁰) to a +1 oxidation state in the complex [Au(CN)₂]⁻, while oxygen is reduced. The formation of the soluble gold - cyanide complex is crucial as it allows the gold, which was initially in a solid, insoluble form within the ore, to be dissolved into the solution. This dissolved gold can then be separated from the remaining ore components through subsequent processing steps, such as adsorption onto Carbon Woyendetsa or precipitation using zinc powder.

Chifukwa chiyani Cyanide? Makhalidwe Apadera a Sodium Cyanide

Sodium cyanide ili ndi zinthu zingapo zomwe zimapangitsa kuti ikhale njira yabwino yopangira golide pamakampani amigodi:

1. Kusankhidwa Kwakukulu kwa Golide: Ma cyanide ions ali ndi kuthekera kodabwitsa kusungunula golide pamaso pa mchere wina wambiri womwe umapezeka mu golide wonyamula miyala. Kusankha kumeneku n'kofunika chifukwa kumapangitsa kuti golide atulutsidwe kuchokera ku miyala yamtengo wapatali kumene golide nthawi zambiri amaphatikizidwa ndi mchere wambiri wa gangue. Mwachitsanzo, mu miyala yomwe ili ndi quartz, feldspar, ndi mchere wina womwe si wamtengo wapatali, cyanide imachita bwino ndi golide, kusiya mchere wambiri wa gangue osakhudzidwa komanso wolekanitsidwa mosavuta ndi golide - womwe uli ndi yankho.

2. Kusungunuka Kwambiri M'madzi: Sodium cyanide imasungunuka kwambiri m'madzi, yomwe ndiyofunikira kuti igwiritsidwe ntchito pakupanga leaching. Kusungunuka kwapamwamba kumatsimikizira kuti ma ion a cyanide amatha kumwazikana mwachangu mumatope a ore, kukulitsa kulumikizana pakati pa cyanide ndi tinthu tagolide. Kubalalitsidwa kofulumiraku kumabweretsa kufulumira kwakuchitapo kanthu komanso kubweza golide. Mwachitsanzo, pa firiji, kwambiri kuchuluka kwa sodium cyanide imatha kusungunuka m'madzi, ndikupatsanso ma ayoni ambiri a cyanide mu njira ya leaching.

3. Mtengo wofananira - Kuchita bwino: Poyerekeza ndi zopangira zina zomwe zingagwiritsidwe ntchito pochotsa golide, sodium cyanide ndi yotsika mtengo. Kukwera mtengo kumeneku ndi chifukwa chachikulu chomwe chimagwiritsidwa ntchito kwambiri m'migodi ya golide, makamaka pantchito zazikulu. Ogwira ntchito m'migodi amatha kupeza sodium cyanide yochuluka pamtengo wokwanira, zomwe zimathandiza kusunga mtengo wonse wa kutulutsa golide mkati mwazochita zachuma.

4. Kukhazikika mu Alkaline Solutions: Cyanide ndi yokhazikika muzitsulo za alkaline, zomwe zimakhala zopindulitsa mu ndondomeko ya leaching. Posunga njira yotulutsa madzi pa pH yokwera (nthawi zambiri pafupifupi 10 - 11), kuwonongeka kwa cyanide kukhala hydrogen cyanide (HCN), mpweya wapoizoni kwambiri komanso wosakhazikika, kumatha kuchepetsedwa. Kukhazikika kumeneku kumatsimikizira kuti cyanide imakhalabe mawonekedwe ake okhazikika kwa nthawi yayitali, zomwe zimapangitsa kuti golide asungunuke bwino. Laimu nthawi zambiri amawonjezeredwa ku yankho la leaching kuti asunge malo amchere komanso kuti cyanide ikhale yokhazikika.

Njira Yapang'onopang'ono ya Cyanide Leaching mu Migodi ya Golide

Kuchiza: Kuphwanya ndikupera

Njira yotulutsa cyanide isanayambe, miyala yokhala ndi golide imadutsa gawo lofunikira kwambiri lokonzekera bwino. Gawo loyamba pagawoli ndikuphwanya, komwe kuli kofunikira kuti muchepetse tinthu tating'onoting'ono ta miyala yamtengo wapatali. Izi zimatheka pogwiritsa ntchito ma crushers angapo, monga ma nsagwada, ma cone, ndi ma gyratory crushers. Mwachitsanzo, chophwanya nsagwada, chimakhala ndi dongosolo losavuta komanso chiŵerengero chophwanyidwa kwambiri. Imatha kuthana ndi miyala ikuluikulu ndikuyamba kuwaphwanya kukhala tizidutswa tating'ono.

Akamaliza kuphwanyidwa, chitsulocho amachipera. Akupera ikuchitika kuti kuonjezera kuchepetsa tinthu kukula kwa ore, kawirikawiri mu mpira mphero kapena ndodo mphero. Pamphero, mipira yachitsulo imagwiritsidwa ntchito pogaya zitsulo. Pamene mphero ikuzungulira, mipirayo imatsika, kukhudza ndikupera tinthu tating'onoting'ono. Njira imeneyi ndi yofunika chifukwa imachulukitsa pamwamba pa miyala. Malo okulirapo amatanthauza kuti pali kukhudzana kwambiri pakati pa golidi - wokhala ndi tinthu tating'onoting'ono mkati mwa ore ndi njira ya cyanide panthawi ya leaching.

Mwachitsanzo, ngati chitsulocho sichinaphwanyidwe bwino ndi kuphwanyidwa bwino, tinthu tating'ono ta golide tingatsekere m'kati mwa tinthu tambirimbiri ta chitsulo. Njira ya cyanide ikadakhala yovuta kufikira tinthu tagolide tating'ono, zomwe zimapangitsa kuti achuluke kwambiri. Pochepetsa miyalayo kukhala ufa wabwino pogaya, golidiyo amakhala wofikirika kwambiri ndi ma cyanide ions, kumapangitsa kuti ntchitoyo ikhale yabwino.

The Leaching Stage: Stirred Leaching vs. Heap Leaching

Mwala ukakonzedwa bwino, siteji yokhomerera imayamba, ndipo pali njira ziwiri zazikulu: kusonkhezera ndi kukhetsa milu.

Kuthamanga kwa Leaching

Posonkhezera, miyala yamtengo wapatali imasakanizidwa ndi yankho la cyanide mu thanki yaikulu, yomwe nthawi zambiri imatchedwa tank leaching kapena tank agitator. Makina oyambitsa, monga ma impellers, amagwiritsidwa ntchito kulimbikitsa kusakaniza mosalekeza. Kugwedezeka kosalekeza kumeneku kumagwira ntchito zingapo zofunika. Choyamba, zimawonetsetsa kuti yankho la cyanide limagawidwa mofanana pamatope ore. Kugawa ngakhale kumeneku ndikofunikira chifukwa kumapangitsa kuti tinthu tating'ono tokhala ndi golide tikhale ndi mwayi wofanana wochita ndi ma cyanide ions. Kachiwiri, mukubwadamuka kumathandiza kuti particles ore mu kuyimitsidwa, kuwalepheretsa kukhazikika pansi pa thanki. Izi ndizofunikira chifukwa ngati tinthu tating'ono takhazikika, zomwe zimachitika pakati pa golide ndi cyanide zitha kuletsedwa.

Kuthamanga kothamanga nthawi zambiri kumakondedwa ndi ore apamwamba kwambiri kapena pamene kuchira kumafunika nthawi yochepa. Ndiwoyeneranso ku ma ore omwe ndi ovuta kutsika, chifukwa chipwirikiticho chimatha kukulitsa kulumikizana pakati pa chitsulo ndi cyanide solution. Komabe, kusonkhezera leaching kumafuna mphamvu zambiri chifukwa cha ntchito yosalekeza ya oyambitsa. Ilinso ndi mtengo wokwera chifukwa imafunikira zida zazikulu komanso kuchuluka kwa cyanide solution.

Kuchuluka kwa Leaching

Kuchulukirachulukira, kumbali ina, ndi njira yotsika mtengo - yothandiza, makamaka ya ore otsika. Pochita izi, ore wophwanyidwawo amawunjikidwa mumilu yayikulu, nthawi zambiri pamtambo wosasunthika kuti cyanide solution isatayike. Mankhwala a cyanide amawapopera kapena kudonthezedwa pamwamba pa mulu wa miyalayo. Pamene yankho likuyenda mu mulu, limakumana ndi golide mu ore, ndikulisungunula ndikupanga golide - cyanide complex. Nkhokwe, yomwe imakhala ndi golidi wosungunuka, imakhetsa pansi pa mulu ndipo imasonkhanitsidwa m'dziwe kapena thanki kuti ikonzedwenso.

Mulu wa leaching ndi njira yoyenera kwambiri pochita ntchito zazikulu zokhala ndi ore otsika, chifukwa zimafuna ndalama zochepa pazida poyerekeza ndi zowotchera. Ilinso ndi mphamvu zochepa zomwe zimafunikira chifukwa palibe chifukwa chokhalira kugwedezeka. Komabe, leaching ya mulu imakhala ndi nthawi yotalikirapo yotsatsira poyerekeza ndi kugwedezeka kwamphamvu, ndipo kuchuluka kwa kuchira kumatha kutsika pang'ono. Kupambana kwa milu ya milu kumadaliranso zinthu monga kupenya kwa mulu wa miyala. Ngati muluwu sunamangidwe bwino ndipo tinthu tating'ono tomwe tadzaza kwambiri, yankho la cyanide silingathe kulowa molingana, zomwe zimabweretsa kutsika kosagwirizana ndikutsitsa golide.

Post-leaching Processing: Kupeza Golide ku Njira

Golidi atasungunuka mu njira ya cyanide panthawi ya leaching, chotsatira ndikubwezeretsanso golide ku yankho ili. Pali njira zingapo zomwe zimagwiritsidwa ntchito pazifukwa izi, ziwiri mwazofala kwambiri ndi activated carbon adsorption ndi zinc fumbi simenti.

Adayambitsa Carbon Adsorption

Mpweya wokhala ndi activated uli ndi malo akulu komanso ogwirizana kwambiri ndi golide - ma cyanide complexes. Mu activated carbon adsorption process, yomwe imadziwikanso kuti carbon - in - pulp (CIP) kapena carbon - in - leach (CIL) process, activated carbon imawonjezeredwa ku leachate. Golide - cyanide complexes mu yankho amakopeka pamwamba pa mpweya wopangidwa ndi mpweya ndipo amawakomera pamenepo. Izi zimapanga carbon "yodzaza" kapena "yoyembekezera", yomwe imasiyanitsidwa ndi yankho.

Kupatukana kwa carbon yodzaza ndi yankho kungapezeke mwa kuwunika kapena kusefera. Akalekanitsidwa, golidiyo amachotsedwa ku carbon yopakidwayo. Izi kawirikawiri zimachitika kudzera mu njira yotchedwa elution kapena desorption, kumene golide amachotsedwa mu carbon pogwiritsa ntchito njira yotentha, yokhazikika ya sodium cyanide ndi sodium hydroxide. Zotsatira zake, zomwe zimakhala ndi golide wambiri, zimasinthidwanso kudzera mu electrolysis kuti golideyo asungidwe pa cathode, zomwe zimapangitsa kupanga golide weniweni.

Zinc Fumbi Cementation

Simenti ya zinc fumbi, yomwe imadziwikanso kuti Merrill - Crowe process, ndi njira ina yomwe imagwiritsidwa ntchito kwambiri pobweza golide ku leachate. Pochita izi, fumbi la zinki limawonjezeredwa ku yankho lomwe lili ndi golide - cyanide complex. Zinc imakhala yotakasuka kwambiri kuposa golide, ndipo imachotsa golide kuchokera kuzovuta motengera zotsatirazi:

2Na[Au(CN)₂] + Zn → Na₂[Zn(CN)₄] + 2Au

Golide ndiye amachotsedwa mu yankho ngati cholimba, kupanga golide - zinc precipitate. Mpweya uwu umasefedwa ndikulekanitsidwa ndi yankho. Golide amayengedwanso mwa kusungunula madziwo kuti achotse zinki ndi zonyansa zina, zomwe zimapangitsa kupanga golide weniweni. Simenti ya fumbi la Zinc ndi njira yosavuta komanso yowongoka, koma imafunika kuwongolera mosamala pH komanso kuchuluka kwa yankho la cyanide kuti zitsimikizire kuchira kwagolide.

Zomwe Zimakhudza Kuchita Bwino kwa Cyanide Leaching

Makhalidwe a Ore

Mkhalidwe wa golide wokhala ndi miyala ndi chinthu chofunikira kwambiri chomwe chimapangitsa kuti cyanide leaching igwire bwino ntchito. Mitundu yosiyanasiyana ya ore, monga golide wa sulfide ndi oxidized ores golide, ali ndi mawonekedwe apadera omwe amatha kukhudza kwambiri njira yolowera.

Mafuta a Sulfidi Gold Ores: Ores golide wa sulfide nthawi zambiri amakhala ndi mchere wambiri wa sulfide, monga pyrite (FeS₂), arsenopyrite (FeAsS), ndi chalcopyrite (CuFeS₂). Michere ya sulfide iyi imatha kubweretsa zovuta zingapo panthawi ya cyanide leaching. Mwachitsanzo, pyrite ndi mchere wamba wa sulfide mu golide - wokhala ndi miyala. Pamene pyrite ilipo mu ore, imatha kuchitapo kanthu ndi yankho la cyanide ndi mpweya m'malo otsetsereka. Kuchuluka kwa okosijeni wa pyrite pamaso pa okosijeni ndi cyanide kumatha kupangitsa kuti pakhale zinthu zosiyanasiyana, monga sulfuric acid (H₂SO₄) ndi ma iron - cyanide complexes. Mapangidwe a sulfuric acid amatha kutsitsa pH ya njira ya leaching, yomwe imawononga kukhazikika kwa cyanide. Kuphatikiza apo, zomwe mchere wa sulfide wokhala ndi cyanide zimatha kudya cyanide yambiri, ndikuwonjezera mtengo wa reagent. Mwachitsanzo, mu miyala ya sulfide yomwe ili ndi sulfide wambiri, kumwa kwa cyanide kumatha kuwirikiza kangapo kuposa komwe kulibe miyala ya sulfide.

Oxidized Gold Ores: Komano, oxidized golide ores, nthawi zambiri amakhala ndi malo abwino otsetsereka poyerekeza ndi miyala ya sulfide. Ma orewa adakumana ndi nyengo komanso kutulutsa okosijeni, zomwe zatulutsa kale mchere wambiri wa sulfide kukhala mawonekedwe okhazikika a oxide. Zotsatira zake, mavuto okhudzana ndi sulfide - cyanide amachepetsedwa. Golide wokhala ndi oxidized ores nthawi zambiri amapezeka mosavuta ku cyanide solution popeza kapangidwe kake kamakhala kochulukira komanso kocheperako. Mwachitsanzo, mu golide wa laterititic ore, womwe ndi mtundu wa oxidized ore, golide nthawi zambiri amapezeka mu mawonekedwe obalalika komanso ocheperako. Izi zimathandiza kuti ayoni a cyanide afikire mosavuta tinthu tating'ono ta golide, zomwe zimapangitsa kuti pakhale kutulutsa bwino kwambiri. Komabe, oxidized ores angakhalenso ndi zosafunika zina, monga chitsulo oxides ndi hydroxides, amene akhoza adsorb golide - cyanide zovuta kapena kusokoneza ndondomeko leaching pamlingo wina.

Kukula kwa tinthu ting'onoting'ono kwa golide mkati mwa miyalayi kumathandizanso kwambiri. Tinthu tating'onoting'ono tomwe timakhala ndi golide timakhala ndi malo okulirapo - mpaka - kuchuluka kwa voliyumu, zomwe zikutanthauza kuti amatha kuchitapo kanthu mwachangu ndi yankho la cyanide. Mosiyana ndi izi, tinthu tating'ono ta golide tating'onoting'ono tingafunike nthawi yotalikirapo kapena mikhalidwe yoyipa kwambiri kuti muchepetse kuchira. Mwachitsanzo, ngati tinthu tagolide tating'onoting'ono kwambiri, cyanide yankho silingathe kulowa mkati mozama mu tinthu tating'onoting'ono, ndikusiya golide wina osakhudzidwa.

Kukhazikika kwa Cyanide

Kuchuluka kwa sodium cyanide mu leaching solution ndi gawo lofunikira lomwe limakhudza mwachindunji kutulutsa golide komanso mtengo wonse wantchitoyo.

Zotsatira pa Leaching Mwachangu: Pamene ndende ya cyanide ikuwonjezeka, mlingo wa zomwe zimachitika pakati pa golide ndi cyanide poyamba umawonjezeka. Izi zili choncho chifukwa kuchuluka kwa ma cyanide ion kumapereka mamolekyu ambiri omwe amatha kulumikizana ndi tinthu tagolide. Mwachitsanzo, pakuyesa kwa labotale, pamene ndende ya cyanide ikuwonjezeka kuchokera ku 0.01% kufika ku 0.05%, kusungunuka kwa golidi kumatha kuwonjezeka kwambiri, zomwe zimapangitsa kuti golide abwererenso pakapita nthawi yochepa. Komabe, ubalewu suli wa mzere mpaka kalekale. Pamene ndende ya cyanide ifika pamlingo wina, kuwonjezereka kwina sikungabweretse kuwonjezereka kwa chiwerengero cha kusungunuka kwa golide. M'malo mwake, ndende ya cyanide ikakwera kwambiri, imatha kuyambitsa hydrolysis ya cyanide. Cyanide hydrolysis imachitika pamene cyanide imachita ndi madzi kupanga hydrogen cyanide (HCN) ndi ayoni a hydroxide (OH⁻). Zomwe zimachitika ndi izi: CN⁻+H₂O⇌HCN + OH⁻. Hydrogen cyanide ndi mpweya wokhazikika komanso wapoizoni kwambiri. Kupangidwa kwa HCN sikungochepetsa cyanide yomwe ikupezeka pakupanga golide - leaching reaction komanso kumabweretsa chiwopsezo chachikulu chachitetezo komanso chilengedwe.

Kuganizira za Mtengo: Cyanide ndi reagent yokwera mtengo, makamaka poganizira ntchito zazikulu za migodi ya golide. Kugwiritsa ntchito kuchuluka kwa cyanide kuposa kufunikira kumatha kukulitsa mtengo wopangira. Mwachitsanzo, pakuchulukirachulukira - ntchito yotulutsa cyanide, ngati kuchuluka kwa cyanide kumachulukitsidwa ndi 0.05% kuposa momwe mulingo woyenera, mtengo wapachaka wa cyanide ukhoza kuwonjezeka ndi kuchuluka kwakukulu, kutengera kuchuluka kwa yankho la leaching ndi kukula kwa ntchitoyo. Kumbali inayi, kugwiritsa ntchito ndende yotsika kwambiri ya cyanide kumabweretsa kuchepa kwapang'onopang'ono, komwe kungafunike nthawi yotalikirapo kapena kuchulukira kwa yankho la leaching kuti mukwaniritse kuchira kwa golide. Izi zitha kuonjezeranso mtengo wonse chifukwa cha nthawi yayitali yokonza, kugwiritsa ntchito mphamvu zambiri, komanso kutsika kwapang'onopang'ono.

Nthawi zambiri, pazantchito zambiri za golide - migodi, mtundu woyenera wa cyanide uli pakati pa 0.03% ndi 0.1%. Komabe, mitundu iyi imatha kusiyanasiyana kutengera mtundu wa ore, kupezeka kwa zonyansa, komanso njira yomwe imagwiritsidwa ntchito. Mwachitsanzo, pakugwedezeka kwa golide woyengedwa bwino, kutsika kwa cyanide pakati pa 0.03% - 0.05% kungakhale kokwanira. Mosiyana ndi izi, chifukwa cha sulfide yovuta - yokhala ndi miyala ya golide mu mulu - ntchito ya leaching, ndende yokwera pang'ono ya cyanide, mwina pafupi ndi 0.08% - 0.1%, ingafunikire kulipira cyanide ndi mchere wa sulfide.

pH Mtengo wa Solution

Phindu la pH la yankho la cyanide leaching ndilofunika kwambiri pakupanga golide - cyanide leaching process, chifukwa imakhudza kukhazikika kwa cyanide, kusungunuka kwa golide, komanso dzimbiri la zida.

Kukhazikika kwa Cyanide: Cyanide imakhala yokhazikika m'malo amchere. Pamene pH ya yankho ili m'kati mwa 10 - 11. hydrolysis ya cyanide, yomwe imapanga mpweya wa poizoni wa hydrogen cyanide (HCN), imachepetsedwa. Monga tafotokozera kale, hydrolysis reaction ya cyanide ndi CN⁻+H₂O⇌HCN + OH⁻. Mu njira ya alkaline, kuchuluka kwa ayoni a hydroxide (OH⁻) kumasinthira kufananiza kwazomwezi kumanzere, kumachepetsa mapangidwe a HCN. Mwachitsanzo, ngati pH ya njira yothetsera leaching ikugwera ku 8 kapena kutsika, mlingo wa cyanide hydrolysis udzawonjezeka kwambiri, zomwe zimabweretsa kutaya kwa cyanide ndi chiopsezo chowonjezereka cha kumasulidwa kwa HCN, zomwe sizongowonongeka za reagent komanso chiopsezo chachikulu cha chitetezo kwa ogwira ntchito ndi chilengedwe.

Kusungunuka kwa Golide: Kusungunuka kwa golide - cyanide complex kumakhudzidwanso ndi pH mtengo. Pa pH yoyenera ya alkaline, mapangidwe a golide wosungunuka - cyanide complex, monga Na[Au(CN)₂], amakondedwa. pH ikakhala yotsika kwambiri, zovutazo zimatha kuwola, kuchepetsa kuchuluka kwa golide mu yankho ndikuchepetsa mphamvu ya leaching. Kuonjezera apo, m'malo a acidic, ma ion ena achitsulo omwe amapezeka mu ore amatha kusungunuka mosavuta, kusokoneza ndondomeko ya golide. Mwachitsanzo, ayoni ayironi (Fe³⁺) ochokera ku chitsulo - okhala ndi mchere mu ore amatha kupanga ma precipitates kapena ophatikizana ndi cyanide mu acidic solution, kupikisana ndi golide wa ma cyanide ayoni.

Kuwonongeka kwa Zida: Kusunga pH yolondola ndikofunikiranso pakuteteza zida zomwe zimagwiritsidwa ntchito poyendetsa. M'malo okhala acidic, yankho la cyanide limatha kuwononga kwambiri zida zachitsulo, monga matanki otulutsa, mapaipi, ndi mapampu. Mwachitsanzo, akasinja opangidwa ndi chitsulo amatha kuwononga mwachangu mu njira ya acidic cyanide, zomwe zimapangitsa kuti pakhale kutayikira komanso kufunikira kosinthira zida pafupipafupi, zomwe zimawonjezera mtengo wopanga komanso nthawi yocheperako. Mosiyana ndi izi, yankho la alkaline silingawononge zinthu zambiri zomwe zimagwiritsidwa ntchito pazida zagolide.

Kuti pH ikhale yoyenera, laimu (CaO) kapena sodium hydroxide (NaOH) nthawi zambiri amawonjezedwa ku yankho la leaching. Laimu ndi chinthu chomwe chimagwiritsidwa ntchito kwambiri posintha pH pakuchita migodi - chifukwa chotsika mtengo komanso kuchita bwino. Imachita ndi madzi kupanga calcium hydroxide (Ca(OH) ₂), yomwe imatha kusokoneza zigawo zilizonse za acid mu yankho ndikuwonjezera pH. Kuonjezera laimu kumakhalanso ndi phindu lowonjezera la zitsulo zazitsulo, monga chitsulo ndi mkuwa, zomwe zingachepetse kusokoneza kwawo mu ndondomeko ya leaching.

Kutentha ndi Leaching Time

Kutentha ndi nthawi ya leaching ndi zinthu ziwiri zogwirizana zomwe zimakhudza kwambiri mphamvu ya cyanide leaching.

Zotsatira za Kutentha: Kuwonjezeka kwa kutentha nthawi zambiri kumabweretsa kuwonjezeka kwa kuchuluka kwa cyanide - golide. Izi zili choncho chifukwa kutentha kwapamwamba kumawonjezera mphamvu ya kinetic ya mamolekyu a reactant, kuphatikizapo ma cyanide ions ndi maatomu a golide pamtunda wa ore. Zotsatira zake, kugundana kwapakati pakati pa reactants kumawonjezeka, ndipo kuchuluka kwa zomwe zimachitika kumathamanga. Mwachitsanzo, mu kuyesa kwa labotale, pamene kutentha kwa njira ya leaching kwakwera kuchokera pa 20 ° C mpaka 40 ° C, kusungunuka kwa golide kumatha kuwirikiza kawiri kapena katatu nthawi zina. Komabe, pali zolepheretsa kuonjezera kutentha. Pamene kutentha kumakwera, kusungunuka kwa okosijeni mu yankho kumachepa. Popeza mpweya ndi wofunikira wothira oxidizing mu golide - cyanide reaction, kuchepa kwa kusungunuka kwa okosijeni kumatha kuchepetsa kuchuluka kwa zomwe zimachitika. Pa kutentha kwambiri, pafupi ndi 100 ° C, kusungunuka kwa okosijeni kumakhala kochepa kwambiri, ndipo njira yotulutsa mpweya imakhala yochepa. Kuphatikiza apo, kutentha kwambiri kungayambitsenso kuchuluka kwa cyanide hydrolysis, monga tanena kale, zomwe zimachepetsa cyanide yomwe ilipo pakupanga golide - leaching reaction. Kuphatikiza apo, kutentha kokwezeka kumatha kufulumizitsa kuwononga kwa zida, kuonjezera mtengo wokonza ndikuchepetsa moyo wa zida. Nthawi zambiri migodi ya golide, kutentha kwa leaching kumasungidwa pamlingo wocheperako, nthawi zambiri pakati pa 15 ° C ndi 30 ° C. Kutentha kumeneku kumapereka kulinganiza pakati pa momwe zimachitikira, kusungunuka kwa okosijeni, kukhazikika kwa cyanide, ndi kulimba kwa zida.

Zotsatira za Leaching Time: Nthawi ya leaching imakhudzana mwachindunji ndi kuchuluka kwa golidi komwe kumatha kuchotsedwa muzitsulo. Kawirikawiri, pamene nthawi ya leaching ikuwonjezeka, golide wochuluka adzasungunuka mu njira ya cyanide. Komabe, mgwirizano pakati pa leaching nthawi ndi kuchira golide si mzere. Poyambirira, mlingo wa kusungunuka kwa golide ndi wokwera kwambiri, ndipo golide wochuluka akhoza kuchotsedwa pakanthawi kochepa. Koma pamene ndondomeko ya leaching ikupitirira, mlingo wa kusungunuka kwa golide umachepa pang'onopang'ono. Izi ndichifukwa choti tinthu tating'ono ta golide timasungunuka poyamba, ndipo pakapita nthawi, golide wotsalayo amakhala ovuta kufikako chifukwa cha zinthu monga kupanga zinthu zomwe zimachitikira pamtunda wa ore zomwe zimatha kukhala chotchinga. Mwachitsanzo, poyambitsa ntchito ya leaching, gawo lalikulu la golide likhoza kusungunuka mkati mwa maola 24 - 48 oyambirira. Pambuyo pake, kuwonjezereka kwa nthawi yowonongeka kungapangitse kuwonjezeka kwapang'onopang'ono kwa kubwezeretsa golide. Kutalikitsa nthawi ya leaching kwambiri kungakhale kopanda ndalama chifukwa kumawonjezera mtengo wogwirira ntchito, kuphatikiza kugwiritsa ntchito mphamvu, kugwiritsa ntchito ma reagent, ndi mtengo wantchito. Panthawi imodzimodziyo, zingayambitsenso kusungunuka kwa zonyansa zambiri, zomwe zingasokoneze golide wotsatira - kuchira.

Kuti muwongolere bwino kupanga bwino, kuyenera kukhazikika pakati pa kutentha ndi nthawi ya leaching. Izi nthawi zambiri zimafunikira kuyeserera kwa labotale - kuyezetsa kwakukulu pazatsanzo zinazake za ore kuti mudziwe kuphatikiza koyenera kwa magawo awiriwa. Mwachitsanzo, pamtundu wina wa ore, zikhoza kupezeka kuti kutentha kwa leaching kwa 25 ° C ndi nthawi ya leaching ya maola 36 kumapangitsa kuti golide abwezeretsedwe pamtengo wotsika kwambiri.

Kuganizira za Chitetezo ndi Zachilengedwe

Kuopsa kwa Cyanide: Kusamala ndi Kusunga

Cyanide, mu mawonekedwe a sodium cyanide omwe amagwiritsidwa ntchito pochotsa golide, ndi chinthu chapoizoni kwambiri. Ngakhale pang'ono pang'ono akhoza kupha anthu ndi zamoyo zina. Sodium cyanide ikakumana ndi zidulo, imatha kutulutsa mpweya wa hydrogen cyanide, womwe umakhala wosasunthika kwambiri ndipo umatengedwa mwachangu ndi thupi kudzera mu mpweya. Kulowetsedwa kapena kukhudzana ndi khungu ndi sodium cyanide kungayambitsenso poizoni woopsa. Kuopsa kwa cyanide kumachitika chifukwa chakutha kumangirira ku cytochrome oxidase m'maselo, kusokoneza kupuma kwabwino kwa ma cell ndikupangitsa kuti ma cell asathe kugwiritsa ntchito mpweya, zomwe zimapangitsa kuti maselo afe mwachangu.

Chifukwa cha kawopsedwe kake kwambiri, kusamala koyenera ndi kusungitsa ndikofunikira. Ogwira ntchito yogwiritsira ntchito sodium cyanide ayenera kuphunzitsidwa mokwanira za chitetezo asanagwiritse ntchito mankhwalawa. Zida zodzitetezera, kuphatikizapo magolovesi opangidwa ndi zinthu zoyenera monga nitrile kuteteza khungu, magalasi otetezera maso, ndi zipangizo zotetezera kupuma monga mpweya - masks okhala ndi zosefera zoyenera za hydrogen cyanide, ayenera kuvala nthawi zonse pogwira.

Malo osungiramo sodium cyanide ayenera kukhala pamalo olowera mpweya wabwino, wakutali kutali ndi magwero a kutentha, kuyatsa, ndi zinthu zosagwirizana. Malo osungiramo ayenera kulembedwa momveka bwino ndi zizindikiro zosonyeza kukhalapo kwa mankhwala oopsa kwambiri. Sodium cyanide iyenera kusungidwa muzitsulo zomata zolimba zopangidwa ndi zinthu zomwe sizingawonongeke ndi cyanide, monga mitundu ina ya mapulasitiki kapena zitsulo zosapanga dzimbiri. Zotengerazi ziyenera kusungidwa m'chipinda china chosungiramo zinthu zina, monga thireyi yotsimikizira kutayika kapena kabati yosungiramo yomwe imapangidwira kuteteza kufalikira kwa kutayika kulikonse. Kuyang'anitsitsa nthawi zonse malo osungiramo zinthu ndi zotengera ndizofunikira kuti zitsimikizidwe kuti palibe kutayikira kapena zizindikiro zowonongeka.

Poyenda, sodium cyanide iyenera kunyamulidwa motsatira malamulo okhwima. Magalimoto apadera oyendera omwe ali ndi zida zachitetezo kuti asatayike ndipo amalembedwa momveka bwino kuti amanyamula zinthu zowopsa. Kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe kabwino kake kuti pakhale ngozi.

Environmental Impact and Waste Management

Kugwiritsa ntchito cyanide pakutulutsa golide kumatha kukhala ndi vuto lalikulu la chilengedwe, makamaka chifukwa chotulutsa cyanide - yomwe ili ndi zinyalala. Zowonongeka kwambiri ndi cyanide - madzi oipa ochuluka omwe amapangidwa panthawi ya leaching. Ngati madzi oipawa sanasankhidwe bwino ndipo amatulutsidwa m’chilengedwe, akhoza kukhala ndi zotsatirapo zoipa pa zamoyo za m’madzi.

Cyanide ndi poizoni kwambiri kwa zamoyo zam'madzi. Ngakhale m'malo otsika kwambiri, imatha kupha nsomba, zamoyo zopanda msana, ndi zamoyo zina zam'madzi. Mwachitsanzo, kuchuluka kwa cyanide kutsika mpaka 0.05 mg/L m'madzi kumatha kupha mitundu yambiri ya nsomba. Kukhalapo kwa cyanide m'madzi kungathenso kusokoneza chakudya m'zamoyo zam'madzi, chifukwa zimatha kupha omwe amapanga ndi ogula, zomwe zimapangitsa kuti pakhale zotsatirapo zoipa pa zamoyo zapamwamba. Kuonjezera apo, madzi oipitsidwa akagwiritsidwa ntchito pa ulimi wothirira, amatha kusokoneza nthaka komanso kuwononga mbewu.

Kuti muchepetse zovuta zachilengedwezi, kuwongolera bwino zinyalala za cyanide - zomwe zili ndi madzi oyipa ndikofunikira. Pali njira zingapo zoyeretsera madzi oipawa:

Njira za Oxidation: Chemical oxidation ndi njira yomwe imagwiritsidwa ntchito kwambiri. Chimodzi mwazinthu zodziwika bwino za okosijeni ndi mankhwala a klorini, monga sodium hypochlorite (bulichi) kapena mpweya wa chlorine. Pamaso pa malo amchere, ma okosijeniwa amatha kuchitapo kanthu ndi cyanide kuti asandutse mankhwala ochepetsa poizoni. Mwachitsanzo, zomwe zimachitika ndi sodium hypochlorite mu njira ya alkaline zimatha kusintha cyanide (CN⁻) poyamba kukhala cyanate (CNO⁻) kenako kupitilira ku carbon dioxide (CO₂) ndi mpweya wa nayitrogeni (N₂) kudzera muzochita zingapo. Zomwe zimachitika zonse zitha kuyimiridwa motere:

2CN⁻+5OCl⁻ + H₂O→2HCO₃⁻+N₂ + 5Cl⁻

Njira ina yothirira okosijeni ndiyo kugwiritsa ntchito hydrogen peroxide (H₂O₂). Hydrogen peroxide imatha kutulutsa cyanide kukhala cyanate pamaso pa chothandizira. Njirayi nthawi zambiri imakonda nthawi zina chifukwa sichipereka zowonjezera zowonjezera monga njira zina zopangira chlorine.

Neutralization ndi Mvula: Nthawi zina, cyanide - yomwe ili ndi madzi oipa imathanso kukhala ndi zitsulo zolemera - cyanide complexes. Posintha pH ya madzi onyansa ndikuwonjezera mankhwala oyenera, zitsulo zolemerazi zimatha kutulutsidwa. Mwachitsanzo, kuwonjezera laimu (CaO) m'madzi otayira kumatha kukweza pH ndikupangitsa mvula yazitsulo zolemera monga mkuwa, zinki, ndi chitsulo monga ma hydroxides awo. Cyanide imatha kuthandizidwanso ndi njira zothirira zitsulo zolemera zitachotsedwa.

Chithandizo cha Zachilengedwe: Tizilombo tating'onoting'ono tating'onoting'ono timatha kutsitsa cyanide. M'machitidwe azachilengedwe, monga ma activated - sludge process kapena biofilm reactors, tizilombo tating'onoting'ono timeneti titha kugwiritsidwa ntchito kuphwanya cyanide kukhala zinthu zochepa - zoyipa. Komabe, chithandizo chachilengedwe ndi choyenera kwambiri pamadzi otayirira a cyanide otsika - mpaka - ochepa, chifukwa kuchuluka kwa cyanide kumatha kukhala poizoni kwa tizilombo. Tizilombo tating'onoting'ono timagwiritsa ntchito cyanide ngati gwero la nayitrogeni ndi kaboni, ndikusandulika kukhala ammonia, mpweya woipa, ndi zina zopanda vuto ndi - zopangidwa kudzera munjira zawo zama metabolic.

Kuphatikiza pa kuthira madzi otayira, kuyesetsanso kuchepetsa kuchuluka kwa cyanide yomwe imagwiritsidwa ntchito pochotsa golide ndikubwezeretsanso ndikugwiritsanso ntchito cyanide - yomwe ili ndi mayankho ngati kuli kotheka. Izi zingathandize kuchepetsa kukhudzidwa kwa chilengedwe chonse cha ntchito za migodi ya golide yomwe imadalira cyanide leaching.

Maphunziro a Nkhani ndi Zochita Zamakampani

Nkhani Zopambana: Kuchita Bwino Kwambiri kwa Cyanide Leaching Operations

Ntchito zingapo za migodi ya golidi padziko lonse lapansi zapambana modabwitsa pakukhetsa kwa cyanide, kuyika chizindikiro pamakampani potengera momwe ntchitoyo ikuyendera bwino, yotsika mtengo, komanso kusamalira zachilengedwe.

Chitsanzo chimodzi chotere ndi mgodi wa Yanacocha ku Peru, umodzi mwa migodi yayikulu kwambiri ya golide padziko lonse lapansi. Mgodi wakhazikitsa njira zingapo zatsopano zowonjezeretsera ntchito yake yotulutsa cyanide. Pochita maphunziro atsatanetsatane okhudzana ndi miyala ya miyalayi, mainjiniya a mgodiwo adatha kumvetsetsa bwino momwe chitsulocho chilili. Izi zinawalola kuti azitha kusintha ndende ya cyanide ndi mikhalidwe ya leaching kuti igwirizane ndi makhalidwe enieni a ore. Mwachitsanzo, adapeza kuti pamtundu wina wa ore wokhala ndi sulfide wambiri, kuchuluka pang'ono kwa cyanide pafupifupi 0.08% - 0.1% kumafunika kubweza kuwononga kwa cyanide ndi mchere wa sulfide. Kusintha kolondola kumeneku kwa kuchuluka kwa cyanide sikunangowonjezera kuchuluka kwa golide komanso kunachepetsa kugwiritsa ntchito cyanide pa tani iliyonse ya ore.

Pankhani ya chitetezo cha chilengedwe, mgodi wa Yanacocha wapanga ndalama zambiri m'malo opangira madzi onyansa. Atengera njira yochizira masitepe ambiri yomwe imaphatikiza ma oxidation amankhwala, neutralization, ndi chithandizo chachilengedwe kuti achotse bwino cyanide ndi zonyansa zina m'madzi onyansa. Madzi oyeretsedwawa amawagwiritsanso ntchito pobowoleza, kuchepetsa kudalira kwa mgodi ku magwero a madzi abwino komanso kuchepetsa kuwonongeka kwa chilengedwe.

Nkhani ina yabwino ndi mgodi wa Porgera ku Papua New Guinea. Mgodi uwu wayang'ana kwambiri pakusintha kwazinthu mosalekeza komanso luso laukadaulo. Iwo akhazikitsa dongosolo la state - of - the - art automated control system ya akasinja awo ogwedezeka - leaching. Dongosololi limayang'anira mosalekeza ndikuwongolera magawo monga kuthamanga kwamphamvu, kuthamanga kwa njira ya cyanide, komanso kutentha kwa leaching slurry. Pokhala ndi mikhalidwe yabwino nthawi zonse, mgodi wapeza chiwongola dzanja chambiri chobwezeretsa golide wopitilira 90% m'ntchito zina. Kuphatikiza apo, mgodi wa Porgera wakhala ukuchita nawo kafukufuku ndi chitukuko kuti apeze zopangira zina zomwe zingachepetse kuwonongeka kwa chilengedwe cha njira ya cyanide leaching. Akhala akuyesa mitundu yatsopano ya cyanide - yaulere leaching agents, ngakhale kuti cyanide leaching ikadali njira yayikulu chifukwa chakuchita bwino komanso mtengo wake.

Mavuto Omwe Amakumana Nawo ndi Mayankho Amatengedwa

Ngakhale kuti imagwiritsidwa ntchito kwambiri, kukhetsa kwa cyanide m'migodi ya golidi sikuli kopanda mavuto. Migodi nthawi zambiri imakumana ndi zovuta zosiyanasiyana zomwe zingakhudze momwe ntchitoyi ikuyendera, mtengo wake, komanso kukhazikika kwa chilengedwe.

Complex Ore Properties

Ores ambiri okhala ndi golidi amakhala ndi nyimbo zovuta, zomwe zimatha kuyambitsa zovuta pakutulutsa kwa cyanide. Mwachitsanzo, miyala yamtengo wapatali yokhala ndi arsenic wochuluka, monga yomwe ili m’madipoziti ena kumadzulo kwa United States, ikhoza kukhala yovuta kwambiri kukonza. Arsenic - yokhala ndi mchere, monga arsenopyrite, imatha kuchitapo kanthu ndi cyanide ndi okosijeni, kuwononga cyanide yambiri ndikuchepetsa golide - kutulutsa mphamvu. Kuonjezera apo, kupezeka kwa arsenic mu leachate kungapangitse kuti madzi owonongeka akhale ovuta komanso ovuta chifukwa cha poizoni wa mankhwala a arsenic.

Pofuna kuthana ndi vutoli, migodi ina yatengera njira zochizira. Njira imodzi yodziwika bwino ndiyo kuwotcha, kumene miyalayo imatenthedwa ndi mpweya. Kuwotcha kumawonjezera mchere wa arsenic, kuwasandutsa kukhala okhazikika omwe sangasokoneze njira ya cyanide - leaching. Akawotcha, ore amatha kulowetsedwa bwino ndi cyanide. Njira ina yochizira isanakwane ndi bio-oxidation, yomwe imagwiritsa ntchito tizilombo toyambitsa matenda kuti ipangitse sulfide ndi arsenic - kukhala ndi mchere. Njira imeneyi ndi yabwino kwambiri pa chilengedwe kusiyana ndi kuwotcha chifukwa imagwira ntchito pa kutentha kochepa ndipo imatulutsa mpweya wochepa kwambiri.

Kuonjezera Malamulo a Zachilengedwe

Pamene chidziwitso cha chilengedwe chikukula, ntchito za migodi ya golide zikuyang'anizana ndi malamulo okhwima okhudza kugwiritsa ntchito ndi kutaya cyanide. M'mayiko ambiri, malire ovomerezeka a cyanide m'madzi oipa komanso mpweya wotulutsa mpweya akhwimitsidwa kwambiri. Mwachitsanzo, ku Australia, akuluakulu oyang'anira zachilengedwe akhazikitsa malire okhwima pa kuchuluka kwa cyanide m'madzi onyansa omwe amatulutsidwa m'migodi ya golide. Migodi imayenera kukwaniritsa malirewa kuti apewe chindapusa chambiri komanso kutsekedwa komwe kungachitike.

Kuti atsatire malamulowa, migodi ikugulitsa njira zamakono zoyeretsera madzi oipa. Ena akugwiritsa ntchito njira zotsogola za okosijeni, monga kugwiritsa ntchito kuwala kwa ozone kapena ultraviolet (UV) kuphatikiza ndi hydrogen peroxide, kuti aphwanye bwino cyanide m'madzi onyansa. Njirazi zimatha kukwaniritsa zotsalira zotsalira za cyanide m'madzi oyeretsedwa. Kuphatikiza apo, migodi ikugwiritsanso ntchito njira zowongolera bwino kuti cyanide isatayike ndi kutayikira. Izi zikuphatikizapo kukonza mapangidwe ndi kukonza malo osungiramo zinthu, kugwiritsa ntchito maiwe okhala ndi mizere iwiri ya cyanide - okhala ndi mayankho, ndikugwiritsa ntchito machitidwe owonetsetsa nthawi yeniyeni kuti azindikire kutayikira kulikonse komwe kungatheke mwamsanga.

Mtengo - Kuchita bwino pa Msika Wosakhazikika Wagolide

Mtengo wa ntchito za migodi ya golidi, kuphatikizapo cyanide leaching, ndizovuta kwambiri, makamaka pamsika wa golide wosasunthika. Kusinthasintha kwa mtengo wa golidi kungakhudze kwambiri phindu la migodi. Cyanide, monga reagent yofunika kwambiri pakupanga leaching, imatha kuthandizira kwambiri pamtengo wonse wopanga.

Kuti athane ndi mtengo - magwiridwe antchito, migodi nthawi zonse imayang'ana njira zochepetsera kugwiritsa ntchito reagent ndikuwonjezera magwiridwe antchito. Migodi ina ikugwiritsa ntchito kusanthula kwapamwamba komanso njira zoyendetsedwa ndi data kuti ziwongolere njira zolesekera. Pakuwunika kuchuluka kwazinthu zama ore, mikhalidwe yotsitsa, komanso kubweza golide, amatha kuzindikira magawo omwe amagwirira ntchito pamtengo uliwonse. Izi zimawathandiza kuti achepetse kuchuluka kwa cyanide omwe amagwiritsidwa ntchito popanda kupereka nsembe ya golide. Mwachitsanzo, migodi ina yakhazikitsa makina ophunzirira makina omwe amatha kuneneratu kuchuluka kwa cyanide ndi nthawi yotulutsa potengera kapangidwe kake ndi kagayidwe kake. Kuonjezera apo, migodi ikuyang'ananso kugwiritsa ntchito njira zina, zotsika mtengo - zowonjezera zowonjezera kapena zowonjezera zomwe zingathe kupititsa patsogolo ndondomeko ya leaching ndikuchepetsa kudalira cyanide.

Zam'tsogolo mu Cyanide Leaching Technology

Zamakono Zamakono Zofuna Kupititsa patsogolo Kuchita Bwino ndi Kuchepetsa Zowopsa

Tsogolo laukadaulo wa cyanide leaching uli ndi lonjezo lalikulu ndiukadaulo wambiri wamtsogolo. Chimodzi mwazinthu zofunikira kwambiri ndikukhazikitsa zida zotsogola komanso zogwira ntchito bwino za leaching. Mwachitsanzo, ofufuza akugwira ntchito yokonza matanki a m'badwo watsopano wa leaching omwe ali ndi machitidwe oyendetsa bwino. Machitidwewa amafuna kupititsa patsogolo kusakaniza kwa ore slurry ndi yankho la cyanide, kuonetsetsa kugawidwa kofanana kwazomwe zimapangidwira. A chitukuko posachedwapa ndi ntchito computational madzimadzi dynamics (CFD) kukhathamiritsa kamangidwe ka mukubwadamuka impellers mu akasinja leaching. Potengera njira zoyendetsera slurry ndi yankho, mainjiniya amatha kupanga zotulutsa zomwe zimapereka kusakaniza bwino, kuchepetsa kugwiritsa ntchito mphamvu, komanso kukonza magwiridwe antchito a leaching.

Mbali ina yazatsopano ndikupanga njira zopititsira patsogolo. Traditional batch - mtundu leaching njira nthawi zambiri amavutika ndi kulephera chifukwa cha kufunikira koyambira pafupipafupi - kuyimitsa ndi kutseka - ntchito. Njira zopititsira patsogolo, kumbali inayo, zimatha kugwira ntchito mosalekeza, kuchepetsa nthawi yocheperako ndikuwonjezera zokolola. Makampani ena amigodi akuwunika kale kugwiritsa ntchito ma tank reactors (CSTRs) potulutsa cyanide. Ma reactors awa amatha kugwira ntchito mosasunthika, zomwe zimapangitsa kuti pakhale njira yokhazikika komanso yothandiza. Kuphatikiza apo, njira zotsatsira mosalekeza zitha kuphatikizidwa mosavuta ndi ntchito zina zamagawo munjira ya migodi ya golide, monga kugaya miyala yamtengo wapatali ndi kuchira kwa golide, zomwe zimapangitsa kuti pakhale ntchito yowongoka komanso yothandiza kwambiri.

Pankhani yochepetsa kuopsa kwa chilengedwe ndi chitetezo, matekinoloje atsopano akupangidwa kuti athe kusamalira bwino cyanide - yomwe ili ndi zinyalala. Mwachitsanzo, pali chidwi chochulukirachulukira pakupanga matekinoloje olekanitsa a membrane opangira ma cyanide - madzi oipa ochuluka. Kusefedwa kwa membrane kumatha kuchotsa bwino cyanide ndi zonyansa zina m'madzi otayira, kupanga mtsinje wamadzi waukhondo womwe ungathe kubwezeretsedwanso munjira yotsitsa. Izi sizimangochepetsa kuwonongeka kwa chilengedwe pa ntchito ya migodi komanso zimapulumutsa pakugwiritsa ntchito madzi. Makina ena opangidwa ndi nembanemba adapangidwa kuti aziyenda, kulola chithandizo cha cyanide pamalo - chokhala ndi zinyalala, zomwe zimakhala zothandiza makamaka pantchito zamigodi zakutali.

Kusaka Ma Alternative Leaching Agents

Kusaka kwa njira zina zochotsera ma leaching m'malo mwa sodium cyanide kwakhala gawo lochita kafukufuku m'zaka zaposachedwa. Zomwe zimayendetsa kafukufukuyu ndikufunika kuchepetsa kuopsa kwa chilengedwe ndi chitetezo chokhudzana ndi kugwiritsa ntchito cyanide ndikupeza njira zogwirira ntchito komanso zotsika mtengo.

Chimodzi mwazinthu zodalirika kwambiri zoperekera leaching ndi thiosulfate. Thiosulfate ndi reagent yopanda poizoni yomwe imatha kusungunula golide pamikhalidwe ina. The leaching mechanism ya thiosulfate imaphatikizapo kupanga zovuta pakati pa golide ndi thiosulfate ions pamaso pa oxidizing agent. Poyerekeza ndi cyanide, thiosulfate ili ndi zabwino zingapo. Ndizowopsa kwambiri, zomwe zimachepetsa chitetezo ndi zoopsa zachilengedwe zomwe zimagwirizanitsidwa ndi kugwiritsidwa ntchito kwake. Kuphatikiza apo, thiosulfate leaching sichimakhudzidwa ndi kukhalapo kwa zonyansa zina mu miyala, monga mkuwa ndi chitsulo, zomwe zimatha kusokoneza njira ya cyanide - leaching. Komabe, thiosulfate leaching ilinso ndi zovuta zina. Njira ya leaching nthawi zambiri imakhala yovuta kwambiri ndipo imafuna kuwongolera mosamala pH, kutentha, komanso kuchuluka kwa ma reagents. Mtengo wa thiosulfate ndiwokweranso kwambiri, zomwe zingachepetse kugwiritsidwa ntchito kwake m'migodi yayikulu.

Njira inanso ndiyo kugwiritsa ntchito ma halide-based leaching agents, monga bromide ndi chloride. Othandizira awa amatha kusungunula golide kudzera mu oxidation ndi zovuta. Bromide - based leaching, mwachitsanzo, awonetsa golide wokwera - ziwopsezo zotayika m'maphunziro ena. Komabe, ma leaching agents a halide alinso ndi zovuta zawo. Zitha kukhala zowononga zida, zomwe zimawonjezera mtengo wokonza. Kuonjezera apo, kutaya zinyalala zopangidwa kuchokera ku halide - based leaching process kungakhale kovuta chifukwa cha kuwonongeka kwa chilengedwe kwa halide - yomwe ili ndi zinyalala.

Ma biological leaching agents akufufuzidwanso. Tizilombo tating'onoting'ono, monga mabakiteriya ndi bowa, timatha kupanga ma organic acid kapena zinthu zina zomwe zimatha kusungunula golide. Biological leaching ndi njira yabwino kwa chilengedwe chifukwa sichiphatikiza kugwiritsa ntchito mankhwala oopsa. Komabe, njirayi ndi yochedwa, ndipo mikhalidwe ya kukula kwa tizilombo toyambitsa matenda iyenera kuyang'aniridwa mosamala. Kafukufuku akupitilira kuti apititse patsogolo luso la leaching yachilengedwe ndikupangitsa kuti ikhale njira yabwino yogwirira ntchito zazikulu zamigodi ya golide.

Kutsiliza

Kubwereza Kwa Kufunika ndi Zovuta za Cyanide Leaching mu Migodi ya Golide

Leaching ya cyanide yakhala, ndipo ikupitilizabe kukhala yofunika kwambiri pamakampani amigodi ya golide. Kutha kwake kutulutsa golide kuchokera ku miyala yamtengo wapatali kwapangitsa kuti migodi ya golide ikhale yopindulitsa kwambiri pazachuma. Makhalidwe apadera a sodium cyanide, monga kusankhidwa kwake kwa golide, kusungunuka m'madzi, mtengo - wogwira mtima, komanso kukhazikika kwazitsulo zamchere, zapangitsa kuti ikhale njira yabwino yopangira golide kwa zaka zopitirira zana.

Komabe, ndondomekoyi si yophweka. Kuchita bwino kwa cyanide leaching kumakhudzidwa ndi zinthu zambiri. Makhalidwe a ore, kuphatikiza mtundu wa ore (sulfide kapena oxidized), kupezeka kwa zonyansa monga mchere wa sulfide, ndi kukula kwa tinthu tagolide mkati mwa chitsulocho, kumatha kukhudza kwambiri ntchito yotulutsa. Kuchuluka kwa cyanide mu njira ya leaching, mtengo wa pH wa yankho, kutentha komwe kumatulutsa, komanso nthawi yotulutsa, zonse ziyenera kukonzedwa mosamala kuti zitheke kubweza golide wambiri ndikuchepetsa kugwiritsa ntchito ma reagent komanso kuwononga chilengedwe.

Kuphatikiza apo, poizoni wa cyanide umabweretsa zovuta zazikulu zachitetezo komanso zachilengedwe. Kusamala kolimba ndi kusungirako ndikofunikira kuti muteteze ogwira ntchito ku zotsatira zakupha za cyanide, komanso kuyang'anira zinyalala moyenera ndikofunikira kuti cyanide yomwe ili ndi zinyalala isatuluke m'chilengedwe, zomwe zitha kukhala ndi zotsatira zowononga zachilengedwe zam'madzi komanso thanzi la anthu.

Kuyitanira Kuchitapo Ntchito Zokhazikika komanso Zotetezeka za Migodi ya Golide

Pamene migodi ya golide ikupita patsogolo, ndikofunikira kuti makampani amigodi aziika patsogolo machitidwe okhazikika komanso otetezeka. Izi sizikutanthauza kukhathamiritsa njira yoyendetsera cyanide kuti ikhale yogwira bwino ntchito komanso kuyika ndalama pakufufuza ndi chitukuko kuti tipeze njira zina zomwe zingachepetse kuopsa kwa chilengedwe ndi chitetezo chokhudzana ndi kugwiritsa ntchito cyanide.

M'kanthawi kochepa, makampani amigodi akuyenera kuyang'ana kwambiri pakukhazikitsa njira zoyendetsera chilengedwe. Izi zikuphatikiza kukweza malo opangira madzi oyipa kuti awonetsetse kuti cyanide - yomwe ili ndi zinyalala imakonzedwa bwino isanatayidwe. Makina owunikira nthawi yeniyeni akhazikike kuti azindikire ngati cyanide ikutha kapena kutayikira nthawi yomweyo, kuti ayankhe mwachangu ndi kuchepetsa. Ogwira ntchito akuyenera kuphunzitsidwa mokwanira zachitetezo komanso kupeza zida zaposachedwa zodzitetezera.

Pakapita nthawi, makampani akuyenera kugwirizana ndi mabungwe ochita kafukufuku ndi mayunivesite kuti apititse patsogolo chitukuko cha umisiri wina wa leaching. Kafukufuku wodalirika wa thiosulfate, halide-based, ndi biological leaching agents ayenera kufufuzidwanso ndikuyengedwa. Kuphatikiza apo, ukadaulo wopitilira muyeso wa zida ndi njira zamigodi, monga kupanga matanki otsetsereka ogwirira ntchito bwino komanso njira zotsatsira mosalekeza, zitha kuthandiza kupititsa patsogolo kukhazikika kwa migodi ya golide.

Ogwiritsanso ntchito ali ndi gawo lofunikira. Pofuna golide wotengedwa moyenera, amatha kukopa msika ndikulimbikitsa makampani amigodi kuti atsatire njira zokhazikika komanso zotetezeka. Kupyolera mu zoyesayesa zonsezi, malonda a migodi ya golide akhoza kupitiriza kuyenda bwino pamene akuchepetsa malo ake a chilengedwe ndikuwonetsetsa chitetezo ndi umoyo wa onse omwe akukhudzidwa nawo.