Txoj kev kho cyanide tailings nrog hypochlorite

Introduction

Cyanide siv dav hauv kev lag luam tsuas, tshwj xeeb tshaj yog hauv cov txheej txheem rho tawm kub thiab nyiaj vim nws muaj peev xwm tsim cov khoom sib xyaw ruaj khov nrog cov hlau muaj nqis no. Txawm li cas los xij, qhov muaj cyanide hauv cov tailings ua rau muaj kev pheej hmoo loj rau ib puag ncig thiab kev noj qab haus huv. Cyanide muaj tshuaj lom heev rau cov tsiaj hauv dej, cov nroj tsuag, thiab cov tsiaj txhu, thiab tuaj yeem ua rau cov dej tsis huv yog tias tsis kho kom zoo. Yog li ntawd, cov txheej txheem zoo rau kev tshem tawm cyanide hauv tailings yog qhov tseem ceeb tshaj plaws. Ib txoj hauv kev zoo li no yog kev siv hypochlorite , uas tau pom tias muaj kev cog lus hauv kev rhuav tshem cov tshuaj cyanide thiab txo lawv cov tshuaj lom.

Nkag siab Cyanide hauv Tailings

Qhov chaw ntawm Cyanide hauv Mining Operations

Hauv kev lag luam mining, cyanide feem ntau yog siv rau hauv cov txheej txheem cyanidation, uas yog ib txoj hauv kev rau rho tawm kub thiab nyiaj los ntawm lawv cov ore. Cov txheej txheem cuam tshuam nrog kev tawg ntawm kub thiab nyiaj hauv cov tshuaj cyanide, tsim cov hlau-cyanide complexes soluble. Tom qab cov txheej txheem rho tawm, cov tailings tseem tshuav muaj cov cyanide residual, uas tuaj yeem ua rau hauv daim ntawv dawb cyanide (CN-), complexed cyanide (xws li, hlau-cyanide complexes xws li Cu(CN) 32-), los yog qaug zog cyanide. Qhov concentration ntawm cyanide hauv tailings tuaj yeem sib txawv nyob ntawm seb yam xws li hom ore, txoj kev siv mining thiab extraction, thiab kev ua haujlwm ntawm cyanide rov ua haujlwm.

Environmental and Health Risks of Cyanide in Tailings

Cyanide yog ib yam tshuaj lom neeg uas tuaj yeem cuam tshuam loj heev rau ib puag ncig thiab tib neeg kev noj qab haus huv. Nyob rau hauv ib puag ncig, cyanide tuaj yeem ua rau muaj kuab lom rau cov kab mob hauv dej txawm tias tsawg heev. Nws tuaj yeem cuam tshuam kev ua haujlwm ntawm cov hlwb los ntawm kev cuam tshuam nrog kev ua pa enzyme cytochrome oxidase, ua rau oxygen deprivation thiab thaum kawg tuag. Tsis tas li ntawd, cyanide tuaj yeem hnov ​​​​mob nrog lwm yam khoom hauv ib puag ncig los tsim cov tshuaj lom ntau dua, xws li hydrogen cyanide gas, uas ua rau muaj kev phom sij heev rau tib neeg kev noj qab haus huv.

Rau tib neeg, raug rau cyanide tuaj yeem tshwm sim los ntawm kev nqus pa, noj, lossis kev sib cuag ntawm daim tawv nqaij. Kev raug mob rau cov tshuaj cyanide siab tuaj yeem ua rau cov tsos mob xws li mob taub hau, kiv taub hau, xeev siab, ntuav, ua pa nrawm, thiab mob hnyav, tuaj yeem ua rau coma thiab tuag. Kev cuam tshuam rau cov qib qis ntawm cyanide tuaj yeem ua rau muaj kev noj qab haus huv mus sij hawm ntev, suav nrog kev puas tsuaj rau lub paj hlwb, thyroid caj pas, thiab lub cev xeeb tub.

Hypochlorite: Ib qho Cyanide Destroyer zoo

Hom Hypochlorite siv hauv Cyanide kho

Hypochlorite yog ib qho tshuaj lom neeg uas muaj ClO-ion. Hauv kev kho cov cyanide tailings , ob hom hypochlorite feem ntau siv: sodium hypochlorite (NaClO) thiab calcium hypochlorite (Ca(ClO)2). Sodium hypochlorite yog cov kua ntsuab daj daj uas yooj yim tuav thiab khaws cia. Nws feem ntau siv rau hauv kev siv hauv kev lag luam vim nws cov solubility siab thiab yooj yim ntawm kev siv. Calcium hypochlorite, ntawm qhov tod tes, yog cov khoom dawb uas ruaj khov dua li sodium hypochlorite thiab tuaj yeem siv rau hauv cov xwm txheej uas xav tau qhov chaw hypochlorite ntau dua.

Reaction Mechanism ntawm Hypochlorite nrog Cyanide

Cov tshuaj tiv thaiv ntawm hypochlorite thiab cyanide tshwm sim hauv cov kauj ruam. Hauv thawj kauj ruam, hypochlorite oxidizes cyanide rau cyanate (CNO-). Cov tshuaj tiv thaiv tuaj yeem sawv cev los ntawm kev sib npaug hauv qab no:

CN- + NPO- → CNO- + Cl-

Cov tshuaj tiv thaiv no yog qhov ceev heev thiab tshwm sim nyob rau hauv cov xwm txheej alkaline. Cov cyanate tsim nyob rau hauv kauj ruam no yog tsawg dua lom dua li cyanide, tab sis nws tseem tuaj yeem oxidized ntxiv. Hauv kauj ruam thib ob, cov cyanate yog hydrolyzed thiab ntxiv oxidized los ua Carbon dioxide (CO2), nitrogen gas (N2), thiab chloride ions (Cl-). Tag nrho cov tshuaj tiv thaiv tuaj yeem sawv cev raws li:

2CNO- + 3Cl- + H2O → 2CO2 + N2 + 3Cl- + 2OH-

Kev ua tiav oxidation ntawm cyanide rau cov khoom tsis muaj tshuaj lom yog qhov tseem ceeb rau kev ua kom muaj kev nyab xeeb ntawm cov tailings kho thiab tiv thaiv ib puag ncig.

Cov txheej txheem ntawm Hypochlorite kho rau Cyanide Tailings

Pretreatment ntawm Tailings

Ua ntej cov txheej txheem kho hypochlorite, cov cyanide tailings feem ntau xav tau pretreatment los kho lawv lub cev thiab tshuaj. Qhov no tej zaum yuav muaj xws li cov kauj ruam xws li thickening kom txo qhov ntim ntawm cov tailings slurry, pH hloov los tsim kom tau qhov zoo alkaline tej yam kev mob rau cov tshuaj tiv thaiv nrog hypochlorite, thiab tshem tawm cov khoom hais los yog impurities uas yuav cuam tshuam rau txoj kev kho mob.

Ntxiv ntawm Hypochlorite

Thaum cov tailings yog pretreated, hypochlorite yog ntxiv rau tailings slurry. Tus nqi ntawm hypochlorite yuav tsum tau nyob ntawm ntau yam, suav nrog qhov pib concentration ntawm cyanide hauv tailings, hom hypochlorite siv, thiab qib siab ntawm cyanide puas tsuaj. Feem ntau, ntau tshaj ntawm hypochlorite yog ntxiv los xyuas kom meej oxidation ntawm cyanide. Cov hypochlorite tuaj yeem muab ntxiv rau hauv daim ntawv ntawm cov tshuaj los yog cov khoom, nyob ntawm seb hom hypochlorite thiab kev kho mob.

Cov xwm txheej tiv thaiv thiab saib xyuas

Cov tshuaj tiv thaiv ntawm hypochlorite thiab cyanide tshwm sim nyob rau hauv alkaline tej yam kev mob, feem ntau ntawm pH ntau ntawm 10 - 12. Qhov kub ntawm cov tshuaj tiv thaiv kuj tuaj yeem cuam tshuam cov tshuaj tiv thaiv tus nqi, nrog rau qhov kub thiab txias feem ntau ua rau cov tshuaj tiv thaiv sai. Txawm li cas los xij, nyob rau hauv feem ntau cov ntawv thov kev lag luam, cov tshuaj tiv thaiv yog nqa tawm ntawm qhov kub thiab txias kom txo cov nqi hluav taws xob.

Thaum lub sij hawm kev kho mob, nws yog ib qho tseem ceeb los saib xyuas cov concentration ntawm cyanide, hypochlorite, thiab lwm yam tsis xws li pH thiab kub. Qhov no tuaj yeem ua tiav siv ntau yam kev tshuaj ntsuam xyuas, xws li titration, spectrophotometric, lossis ion-selective electrodes. Kev soj ntsuam tso cai rau kev hloov kho ntawm cov txheej txheem kho mob kom ntseeg tau tias qhov kev xav tau ntawm cyanide kev puas tsuaj tau tiav thiab cov txheej txheem kev kho mob ua haujlwm tau zoo.

Tom qab kev kho mob thiab pov tseg

Tom qab cov tshuaj tiv thaiv ua tiav thiab cov cyanide tau raug puas tsuaj zoo, cov tailings kho tau yuav ua tiav cov kauj ruam tom qab kho. Qhov no tuaj yeem suav nrog kev nruab nrab ntawm pH mus rau ib puag ncig zoo dua, tshem tawm cov khoom seem lossis cov dej nag, thiab kev soj ntsuam zaum kawg kom paub meej tias cov cyanide concentration hauv cov tailings ua tau raws li kev cai tswj hwm. Thaum cov tailings kho tau raws li cov txheej txheem pov tseg, lawv tuaj yeem muab pov tseg kom muaj kev nyab xeeb ntawm qhov tsim nyog, xws li hauv qhov chaw pov tseg lossis qhov chaw pov tseg.

Qhov zoo ntawm Kev Kho Mob Hypochlorite

High Efficiency hauv Cyanide Kev puas tsuaj

Kev kho Hypochlorite tau pom tias muaj txiaj ntsig zoo hauv kev rhuav tshem cyanide hauv tailings. Raws li cov xwm txheej zoo, nws tuaj yeem ua tiav qib siab ntawm cyanide oxidation, txo cov cyanide concentration mus rau qib uas ua tau raws li lossis ntau tshaj cov kev cai. Qhov kev ua haujlwm siab no yog vim muaj zog oxidizing lub zog ntawm hypochlorite, uas tso cai rau nws sai sai nrog cyanide thiab hloov mus rau cov khoom tsis muaj tshuaj lom.

Nqi-ua tau zoo

Piv rau qee txoj kev kho cyanide , xws li electrochemical oxidation lossis ozone kho, hypochlorite kho tuaj yeem tsim nyog tus nqi. Tus nqi ntawm hypochlorite feem ntau qis dua li qee lwm cov neeg sawv cev oxidizing, thiab cov khoom siv thiab cov txheej txheem xav tau rau kev kho hypochlorite yooj yim heev. Tsis tas li ntawd, qhov tshuaj tiv thaiv tuaj yeem ua tiav ntawm qhov kub thiab txias thiab siab, txo cov nqi zog. Txawm li cas los xij, tus nqi tiag tiag ntawm cov txheej txheem kho tuaj yeem sib txawv nyob ntawm cov yam xws li qhov loj ntawm kev ua haujlwm, qhov muaj hypochlorite, thiab tus nqi ntawm kev thauj mus los thiab pov tseg ntawm cov tailings kho.

Yooj yim tuav thiab khaws cia

Sodium hypochlorite, tshwj xeeb, yog ib qho yooj yim los lis thiab khaws cia. Nws yog cov kua uas tau yooj yim pumped thiab dosed rau hauv tailings slurry. Calcium hypochlorite, txawm tias ib qho khoom, tuaj yeem khaws cia thiab ua haujlwm nrog kev ceev faj kom raug. Ob hom hypochlorite yog qhov ruaj khov nyob rau hauv ib txwm cia cov xwm txheej, uas ua rau lawv tsim nyog siv rau hauv kev ua haujlwm tsuas yog qhov chaw khaws cia ntev thiab muaj kev ntseeg siab yog qhov tseem ceeb.

Kev sib tw thiab kev txiav txim siab

Muaj feem cuam tshuam sab nraud

Txawm hais tias kev kho mob hypochlorite ua tau zoo hauv kev rhuav tshem cyanide, tuaj yeem muaj kev cuam tshuam sab nraud uas yuav tshwm sim. Piv txwv li, hypochlorite tuaj yeem hnov ​​​​mob nrog lwm yam khoom muaj nyob hauv cov tailings, xws li sulfides, thiosulfates, thiab organic teeb meem. Cov tshuaj tiv thaiv sab no tuaj yeem haus hypochlorite thiab txo nws cov txiaj ntsig hauv kev puas tsuaj cyanide. Tsis tas li ntawd, qee qhov kev tawm tsam sab nraud tuaj yeem tsim cov khoom lag luam uas tuaj yeem cuam tshuam ib puag ncig lossis kev noj qab haus huv. Piv txwv li, cov tshuaj tiv thaiv ntawm hypochlorite nrog sulfides tuaj yeem tsim cov roj sulfur dioxide, uas yog cov pa phem. Txhawm rau txo qis cov kev cuam tshuam sab nraud, nws yog ib qho tseem ceeb kom ua tib zoo saib xyuas cov tailings thiab optimize cov txheej txheem kev kho tsis zoo.

Kev cuam tshuam rau Tailings Properties

Qhov sib ntxiv ntawm hypochlorite rau tailings kuj tuaj yeem cuam tshuam rau lub cev thiab tshuaj lom neeg ntawm cov tailings. Piv txwv li, cov txheej txheem oxidation tuaj yeem ua rau muaj kev hloov pauv ntawm tus nqi ntawm cov tailings hais, uas yuav cuam tshuam rau lawv cov kev coj cwj pwm thiab kev ua haujlwm ntawm cov txheej txheem sib cais ntawm cov kua. Tsis tas li ntawd, qhov muaj cov hypochlorite residual los yog nws cov tshuaj tiv thaiv cov khoom nyob rau hauv cov tailings kho tej zaum yuav muaj kev cuam tshuam rau lub sij hawm ntev stability thiab ib puag ncig cuam tshuam ntawm tailings. Yog li ntawd, nws yog ib qho tseem ceeb uas yuav tau xav txog cov xwm txheej no thaum tsim thiab siv cov txheej txheem kho hypochlorite.

Kev tswj hwm thiab kev nyab xeeb

Kev siv cov hypochlorite hauv kev kho mob cyanide tailings yog ua raws li kev cai nruj heev. Mines yuav tsum xyuas kom meej tias cov txheej txheem kev kho mob ua tau raws li tag nrho cov kev cai ib puag ncig thiab kev nyab xeeb. Qhov no suav nrog cov kev xav tau rau kev khaws cia, tuav, thiab pov tseg ntawm hypochlorite, nrog rau kev saib xyuas thiab qhia txog cyanide thiab lwm yam kab mob hauv cov tailings kho. Tsis tas li ntawd, hypochlorite yog tus neeg sawv cev oxidizing muaj zog thiab tuaj yeem ua rau muaj kev nyab xeeb yog tias tsis ua haujlwm zoo. Nws yog ib qho tseem ceeb uas yuav tsum tau muab kev cob qhia kom raug rau cov neeg ua haujlwm thiab siv cov kev ntsuas kev nyab xeeb uas tsim nyog, xws li kev siv cov cuab yeej tiv thaiv tus kheej thiab kev teeb tsa cov cuab yeej kev nyab xeeb hauv thaj chaw kho mob.

xaus

Kev kho Hypochlorite yog ib txoj hauv kev siv tau thiab siv tau zoo rau kev rhuav tshem cyanide hauv tailings. Nws muaj ntau qhov zoo, suav nrog kev ua haujlwm siab hauv kev puas tsuaj ntawm cyanide, kev siv nyiaj zoo, thiab yooj yim ntawm kev tuav thiab khaws cia. Los ntawm cov ntaub ntawv tshawb fawb, peb tau pom tias ntau qhov kev ua haujlwm tsuas tau ua tiav cov txheej txheem kho hypochlorite kom ua tau raws li lawv qhov kev ua raws li ib puag ncig thiab txhim kho lawv cov kev ua haujlwm tag nrho.

Txawm li cas los xij, zoo li txhua txoj kev kho mob, kev kho mob hypochlorite kuj muaj qhov nyuaj thiab xav txog. Tej zaum yuav muaj kev cuam tshuam, cuam tshuam rau cov khoom tailings, thiab kev tswj hwm thiab kev nyab xeeb yuav tsum tau ua tib zoo hais. Los ntawm kev nkag siab txog cov xwm txheej no thiab ua kom cov txheej txheem kho kom zoo, cov mines tuaj yeem ua kom muaj kev nyab xeeb thiab siv tau zoo ntawm hypochlorite hauv cyanide tailings kho.

Raws li kev lag luam mining tseem tab tom ntsib kev tshuaj xyuas ib puag ncig, kev txhim kho thiab kev siv cov txheej txheem kev kho mob cyanide kom ruaj khov thiab siv tau zoo, xws li kev kho hypochlorite, yuav ua lub luag haujlwm tseem ceeb hauv kev txo qis ib puag ncig kev cuam tshuam ntawm kev ua haujlwm mining thiab tiv thaiv tib neeg kev noj qab haus huv thiab ib puag ncig.