Cyanide Gold Extraction Wastewater Treatment Process

Parizvino, nzira yekubvisa goridhe recyanide ndiyo imwe yenzira huru dzekucheneswa kwegoridhe muChina. Inoshandisa cyanide solution kubvisa goridhe kubva mumatombo, ine mwero wepamusoro wekudzoreredza, kugona kushanduka kwakasimba kune matombo, uye kugona kugadzira goridhe panzvimbo yacho. Kubva pakatanga kushandiswa cyanide solution kubvisa goridhe kubva mumatombo muna 1887, nzira iyi yave ichishandiswa zvakanyanya kusvika pari zvino. Zvisinei, cyanide gold extraction inogadzira huwandu hwakawanda hwezvinhu zvine chepfu uye zvinokuvadza, zvichikonzera njodzi huru kunharaunda yakapoteredza nevanhu. Naizvozvo, kuti kuderedza kukuvara, zvakakosha kudzidza nzira dzekurapa cyanide gold extraction wastewater. Nhamba huru yevaongorori vakapfupikisa nzira dzekurapa, misimboti yemakemikari, uye mafambiro ekuvandudza cyanide - ine mvura yakasviba, asi vazhinji vavo vanongokurukura nzira imwe kana mbiri chete. Naizvozvo, chinyorwa chino chinoita ongororo yakadzama yenzira dzakasiyana dzekurapa cyanide gold extraction wastewater dziri kushandiswa muindasitiri, ichienzanisa zvakanakira, zvakaipa, uye mamiriro ekushandiswa kwenzira yega yega, iyo ine kukosha kwakati kwekushandisa kwakafanana mukugadzirwa chaiko.

I. Zvitubu uye Njodzi dzeCyanide Gold Extraction Wastewater

Pfungwa huru yekuburitsa goridhe recyanide ndeyekuti munzvimbo ine aerobic, sodium cyanide inobatana negoridhe kugadzira goridhe, iro rinozonyungudika. Mushure meizvozvo, goridhe rinogona kuburitswa nekuwedzerwa kweCarbon adsorption kana kubviswa ne zinc powder kubva kugold cyanide. Panguva imwe chete, dzimwe simbi dzinorema dzakadai sesirivha, mhangura, uye zinc dzinoumbawo complexes uye dzinonyungudika.

MaCyanides anoshandiswa mukuita uye macomplexes anogadzirwa ese ari zvinhu zvine chepfu uye zvinokuvadza. Sodium cyanide iri nyore kunyungudika uye chinhu chine chepfu cheClass 1, chine dose inouraya ye0.10g. Kana maCyanides akadonhera mumvura, anokuvadza zvikuru zvipenyu zviri mumvura, uye anokonzeresa njodzi huru kuvanhu nenzvimbo dzakatenderedza. Nokudaro, kurapwa kwemvura yakasviba inobviswa goridhe yeCyanide kwakakosha zvikuru.

II. Main Kurapa Nzira dzeCyanide Goridhe Kuchera Mvura Yakasviba

Alkaline Chlorination Method

Iyo alkaline chlorination nzira pari zvino ndiyo imwe yenzira dzinonyanya kushandiswa pakurapa cyanide - ine tsvina yetsvina kubva mucyanide goridhe kutorwa. Inonyanya kushandisa chlorine - based oxidants kuti iite oxidize ma cyanides mumvura yetsvina pasi pemamiriro ealkaline, achiashandura kuita asiri - chepfu. Iyo cyanide - breaking process yealkaline chlorination yakakamurwa kuita nhanho mbiri:

Nhanho yekutanga ndeyekuita oxidize cyanide kuita cyanate, iyo inonzi "incomplete oxidation" nhanho. CN⁻ inopindirana neOCl⁻ kutanga kuumba CNCl, yobva yaita hydrolyzes kuCNO⁻. Izvo zvinofanirwa kucherechedzwa kuti CNCl yakanyanya kushanduka uye ine chepfu pasi pemamiriro e acidic. Naizvozvo, panguva yekushanda, iyo pH kukosha inofanira kunyatsodzorwa kuti ive mune alkaline state.

Nhanho yechipiri ndeyekuwedzera oxidize cyanate kucarbon dioxide uye nitrogen, inonzi "complete oxidation" nhanho. Munguva yecyanide - breaking process, iyo pH kukosha ine simba rakakura pane oxidation reaction. Iyo pH kukosha kwekutanga - nhanho oxidation inofanira kudzorwa pa10 - 11. uye nguva yekuita ndeye 10 - 15 maminitsi. Iyo pH kukosha kwechipiri - nhanho oxidation inofanira kudzorwa pa6.5 - 7.0. uye nguva yekuita ndeye 10 - 15 maminitsi.

Mumwe mugodhi unoshandisa nzira yealkaline chlorination kurapa supernatant yecyanide tail slurry (ine cyanide inokwana 200mg/L) uye mvura inobuda kubva mudhangi resedimentation (ine cyanide inokwana 5mg/L). Iyo pH kukosha inodzorwa pa 10 - 11. uye bleaching powder inowedzerwa pachiyero che 35 - 40 nguva ye cyanide yezvinhu zvekuvhenganisa nekukurudzira. Mushure mekuita sedimentation mune thickener, iyo yakazara cyanide yemukati inogona kuderedzwa kusvika 0.1mg/L.

Iyo alkaline chlorination method ndiyo inonyanya kushandiswa pakurapa cyanide - ine tsvina, uye bleaching powder ndiyo inonyanya kushandiswa chlorine - based oxidant. Iyi nzira yakakodzera kurapa cyanide goridhe kudhirowa mvura yetsvina ine yakakwirira kana yakaderera. Inogonawo kubvisa thiocyanate uye cyanide - ine complexes (kunze kweferrocyanide complexes). Iyo medicament inowanikwa zvakanyanya, iyo yakagadzirwa tsvina inosara iri nyore kusefa, uye kushanda kuri nyore. Nekudaro, nharaunda yekushanda ine hutsinye kana uchishandisa bleaching poda kuchenesa mvura yetsvina. Iye zvino mamwe mabhizinesi anoshandisa bleaching fluid kana chlorine dioxide panzvimbo iyo, iyo inovandudza nharaunda yekushanda kusvika pamwero wakati. Asi magasi ane muchetura anogadzirwa panguva yekuita maitiro, uye ine corrosiveness yakakura kumidziyo. Mutengo wemishonga uye mutengo wekugadzirisa wakakwira zvakati.

Ferrous Salt Complexation Method

Iyo ferrous salt complexation nzira inzira yekurapa yecyanide goridhe yekubvisa tsvina yemvura yakabuda mumakore achangopfuura. Nokudzora kuita pH kukosha pa 7 - 8. ferrous ions inobata ne cyanide yakasununguka uye mamwe ma cyanide complexes mu cyanide goridhe rinotora tsvina yemvura kuti iite mvura.

Ongororo dzakaratidza kuti kazhinji, kuwedzera ferrous sulfate chete kurapa cyanide goridhe kudhirowa mvura yetsvina haigone kuita kuti mvura yetsvina isangane nezviyero zvekuburitsa. Naizvozvo, general oxidant inoda kuwedzerwa kumvura yakasviba yakagadziriswa kuti yakadzika - cyanide kubviswa. Chero bedzi mamiriro acho akanyatsogadziriswa, iyo oxidant inogona kuwedzerwa zvakananga kurapwa pasina kuparadzanisa mvura, uye chiyero chekubuda chinogona kuwanikwa zvakare. Izvi zvine zvazvinoreva zvakanaka zvichienzaniswa nemaitiro echivanhu ekuparadzana kutanga uyezve kurapwa.

Imwe goridhe inonyungudutsa inoshandisa sodium sulfide - ferrous sulfate nzira kurapa cyanide - isina mvura mvura. Iyo inofurira ine cyanide inokwana 2500mg/L. Mushure mekurapa, tsvina ine cyanide yemukati isingasviki 20mg/L, ine chiyero chekubvisa che99.2%, inoratidza mhedzisiro inoshamisa. Iyo inotevera yakadzika - kurapwa inoshandisa sodium metabisulfite - mhepo nzira yekudzikisa iyo yakazara cyanide kusvika isingasviki 0.4mg/L.

Iyo ferrous salt complexation nzira ichangobva kubuda nzira yekurapa, inonyanya kushandiswa kurapa yakakwirira-concentration cyanide - ine tsvina. Maitiro ayo ari nyore, iyo-nguva yekudyara idiki, iri nyore kushanda, iyo medicament (kunyanya ferrous sulfate) inowanikwa zvakanyanya, isingadhuri, uye iri nyore kushandisa. Nekudaro, nekuti iyo ferrous sulfate solution ine acidic, kana yakasanganiswa necyanide yegoridhe yekubvisa tsvina, nzvimbo yeko inova acidic, uye pane mukana wekugadzira hydrogen cyanide gasi. Uyezve, haikwanise kubvisa thiocyanate, uye mvura yakacheneswa ichiri kuda kurapwa kwakadzama kuti isangane nemiyero yekuburitsa.

Sodium Metabisulfite - Air Method

Iyo sodium metabisulfite - nzira yemhepo inogadzirwa kubva kune sulfur dioxide - mweya nzira. Inonyanya kushandisa synergistic mhedzisiro ye sodium metabisulfite uye mhepo pane cyanides mumvura yakaraswa mukati meimwe pH renji, ine catalytic mhedzisiro yecopper ions, kuokisisa CN⁻ kuCNO⁻.

Kana iyo cyanide iri mucyanide - ine tsvina yemvura yakakwira, pre-kurapwa kunogona kuitwa kutanga kuderedza huwandu hwecyanide kusvika pasi pe100mg/L. Zvadaro, sodium metabisulfite nemhangura sulfate inowedzerwa, mhepo yakakwana inounzwa, uye pH kukosha inodzorwa (kazhinji inodzorwa pa7 - 8), kuitira kuti cyanide ioxidized kuita cyanate, iyo inobva yagadziriswa nehydrolyzed kuti iite bicarbonate ions uye ammonia.

Iyo sodium metabisulfite - nzira yemhepo yakanakira kurapa yakaderera - concentration cyanide goridhe kuburitsa tsvina. Kuyerwa kwemushonga idiki, kuwanda kwevashandi kwakaderera, asi mari yepamberi yakakura, uye midziyo yakaita semafuridziro inoda kuwedzerwa. Zvinodiwa zvezviratidzo zvemaitiro zvakaomesesa, uye kudzora pH kukosha kwakakosha. Copper sulfate inodawo kuwedzerwa semushonga. The reaction time yakareba. Kana kurapwa kusina kunaka, huwandu hwakawanda hweammonium ions huchagadzirwa, uye slag yakagadzirwa haisi nyore kusefa. Iko kune hushoma hweammonia gasi inogadzirwa pane - saiti, uye haina mhedzisiro pakubvisa thiocyanides.

Hydrogen Peroxide Oxidation Nzira

Iyo hydrogen peroxide oxidation nzira ndeyekuita oxidize cyanides kuCNO⁻ pasi petembiricha yakajairwa, alkaline (pH = 10 - 11) mamiriro, neCu²⁺ sechinhu chinokonzeresa, wozoaisa muhuroyi muzvinhu zvisiri muchetura. Complex cyanides (complexes yeCu, Zn, Pb, Ni, Cd) inoparadzaniswawo nekuda kwekuparadzwa kwe cyanides mavari. Ferrocyanide ions uye mamwe maion anorema esimbi anoumba ferrocyanide yakaoma munyu uye anobviswa. Pakupedzisira, huwandu hwe cyanide mumvura yakasvibiswa inogona kudzikiswa kusvika pasi pe0.5mg/L.

Iyi nzira yakakodzera kurapa yakaderera - concentration cyanide - ine tsvina yemvura. Iyo hydrogen peroxide mishonga yekurapa iri nyore uye iri nyore kuwana otomatiki kutonga. Nekudaro, iyo cyanate inogadzirwa inoda kugara kweimwe nguva yenguva kuti iparare kuita CO₂ neNH₃. Izvo zvisingabatsiri ndezvekuti kushandisa mhangura sechinhu chinokonzeresa kunogona kukonzera mhangura mumvura inoburitswa kuti ipfuure mwero, mutengo wezvinhu zvakasvibirira wakakwira zvakanyanya, thiocyanides haigone kuve oxidized, uye ammonium ions inogadzirwa. Muchokwadi, mvura yetsvina ichine imwe huturu. Uyezve, sezvo hydrogen peroxide iri oxidant, ine corrosiveness yakakura, uye pane mamwe matambudziko nenjodzi mukufambisa nekushandiswa.

Acidification Method

Paunenge uchishandisa nzira yeacidification kurapa cyanide - mvura isina kunaka, maitiro ayo ekuita akaomarara, kunyanya kusanganisira matatu maitiro: iyo acidification process yecyanide - ine tsvina, kubviswa uye kunyura kweHCN gasi, uye maitiro ekusaurura kwemvura yakabviswa.

(1) Acidification reaction: Iyo cyanide - isina mvura mvura inogadziriswa uye inonatswa neasidhi. Iyo yakaoma cyanides mumvura ine urombo inoumba insoluble precipitates yakadai seCuCN, CuSCN, uye Zn₂Fe(CN)₆ uye inobviswa, uye panguva imwe chete, hydrogen cyanide inogadzirwa.

(2) Volatilization uye absorption reaction: Mvura isina kunaka inofanopisa kusvika pa30 ℃ isati yaitwa acidification. Sezvo nzvimbo yekubikira yeHCN ichingori 26.5 ℃, inoshanduka zvakanyanya. Naizvozvo, shongwe yakarongedzwa inoshandiswa seyakawanda-yekuchinjisa michina yekubatana pakati pegasi - mvura mbiri - chikamu mune acidification nzira, iri nyore kuwana kubviswa uye kunyura kweHCN.

(3) Kusashanda zvakanaka: Lime kana alkali yemvura inoshandiswa kudzima mvura yakasara yakabviswa acid. Mamorekuru eHCN akasara ari mumushonga anozoshandurwa kuita CN⁻ form. Nzira yekusimbisa acid inogona kudzosa Sodium Cyanide kubva mumvura yakasviba ine cyanide uye kuita kuti zvinhu zvidzoke. Zvisinei, ine zvinodiwa zvakanyanya zvekuvhara michina, mari yakawanda yekutanga, inoda hunyanzvi hwepamusoro hwekushanda, uye kugadzirisa michina kwakaoma. Kunewo dzimwe njodzi dzekuchengetedza. Mvura yakasviba inogadzirwa mushure mekudzoserwa ichiri kuda kurapwa kwakadzika kuti isangane nezvinodiwa zvekuburitsa mvura.

Electrolysis Method

Nzira ye electrolysis inoshandisa electrochemical redox reactions kuparadza ma cyanides mumvura yakasviba. Munguva yeion electrolysis, macyanides anorasikirwa nemaerekitironi pane anode uye anoiswa oxidized kuita cyanate, carbonate, nitrogen, kana ammonium. Cynate inowedzerwa oxidized kuCO₂ uye H₂O. Zvinonyanya kuita ndezvi:

CN⁻ + 2OH⁻ - 2e → CNO⁻ + H₂O (24)

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

Electrolysis kuyedza uchishandisa self-yakagadzirwa ceramic - based lead lead electrode rod uye stainless - simbi cathode plate yakaratidza kuti nekushandisa nzira ye electrolysis kurapa cyanide - ine tsvina, mushure memaawa maviri eelectrolysis, iyo CN⁻ concentration inogona kudzikiswa kubva pa2mg/L kusvika 385mg/L, uye Cu²⁺ kubva ku58mg/L kusvika ku450mg/L inogona kuderedzwa. Pamusoro pezvo, Hunan Zhongnan Goridhe Smelter inoshandisa nzira ye electrochemical kurapa cyanide goridhe kuburitsa tsvina, iyo inogona kuderedza iyo cyanide yakazara kubva pa48g/L kusvika 4g/L. Musiyano kubva pamusoro apa ndewekuti ese anode uye cathode mahwendefa anogadzirwa nesimbi mahwendefa. Munguva yekushanda, kwete chete simba remagetsi rinopedzwa, asiwo mahwendefa esimbi anopedzwa.

Iyo electrolysis nzira inonyanya kushandiswa kurapa yakakwirira - concentration cyanide - ine tsvina. Iyo midziyo inotora nzvimbo diki, iyo nzira iri nyore uye iri nyore kudzora, asi inopedza huwandu hukuru hwemagetsi emagetsi, uye mutengo wekushandisa wakakwira kupfuura weiyo alkaline chlorination nzira. Iyo cyanide yekubvisa mwero ivhareji, uye haina mhedzisiro pakubvisa cyanide complexes.

Parizvino, pakati penzira dzekurapa dzecyanide goridhe kuburitsa tsvina, iyo alkaline chlorination nzira, acidification nzira, uye sodium metabisulfite - mhepo nzira inoshandiswa zvakanyanya. Iyo electrolysis nzira uye ferrous munyu kusanganisa nzira ichangoburwa nzira dzakashandiswa zvinobudirira mukurapwa kwemaindasitiri. Iyo yehydrogen peroxide oxidation nzira inonyanya nzira yekurapa yekukurumidzira. Kune dzimwe nzira dzakawanda dzekurapa dzekurapa cyanide goridhe kudhirowa mvura yetsvina, yakadai senzira yekuchenesa nzira, nzira yehupenyu, nzira yekuparadzanisa membrane, ion - kuchinjana nzira, etc. Zvisinei, semashandisirwo emaindasitiri, vose vane zvimwe zvinogumira uye vachiri kuda kuvandudzwa kunoramba kuripo.