Gold Cyanidation Plant Cyanide Wastewater Treatment Njira

In Chomera cha Gold Cyanidations, ngakhale zina Madzi a Cyanide ndi zobwezerezedwanso, zilipobe cyanide madzi oipa kapena zotsalira za cyanide zikutayidwa. Cyanide ndi yapoizoni kwambiri, choncho chithandizo chaukatswiri chamadzi otayira a cyanide n'chofunika asanatulutsidwe kuti apewe kuwononga chilengedwe komanso kuwononga thanzi la anthu ndi nyama. Pakadali pano, zotsatirazi ndi njira zodziwika bwino zochizira madzi a cyanide muzomera zagolide za cyanidation.

Njira Zochizira Madzi Otayira a Cyanide Apakati ndi Otsika

Njira ya Alkaline Chlorination

Njira yogwiritsira ntchito alkaline chlorination ndi njira yomwe imagwiritsidwa ntchito kwambiri. Mu njira iyi, chlorine oxidant yokhala ndi mphamvu yowonjezereka imawonjezeredwa ku madzi otayira a alkaline cyanide. Ma oxidant wamba ndi ClO₂, Cl₂ (gasi ndi madzi), ufa wothira, sodium hypochlorite, calcium hypochlorite, ndi chlorite. Mu yankho la alkaline, OCl⁻ kapena chloride yokhala ndi mphamvu yowonjezereka nthawi zambiri imapangidwa. Choyamba, cyanide imasungunuka kukhala cyanate, kenako imasungunukanso kukhala Carbon dioxide ndi nayitrogeni.

• Ubwino : Ma reagents amapezeka kwambiri ndipo ndi otsika mtengo. Zotsatira zake ndi zabwino, ndipo zida zomwe zimagwiritsidwa ntchito ndizosavuta, zomwe ndizosavuta kuzikonza zokha.

• Zoyipa : Popeza cyanogen chloride yopangidwa ndi poizoni, ndi yoopsa kwambiri kwa ogwiritsa ntchito. Cyanogen chloride ikakhudzana ndi madzi imatha kutulutsa utsi wowononga, zomwe zimapangitsa kuti zipangizo ziwonongeke kwambiri.

Njira ya Inco

Njira ya Inco inapangidwa ndi Inco Ltd. mu 1982. Zimaphatikizapo kuwonjezera chisakanizo cha SO₂ ndi mpweya kumadzi onyansa a cyanide ndikuwongolera pH mtengo pakati pa 8 - 10. Ma ions amkuwa a divalent amachititsa kuti okosijeni wa cyanide awonongeke m'madzi onyansa.

• Ubwino : Njira ya Inco ndi yosavuta, ndipo zida zomwe zimagwiritsidwa ntchito sizovuta. Zotsatira zake nthawi zambiri zimakhala bwino kuposa njira yopangira chlorine (popanda kuganizira za poizoni wa thiocyanate). Magwero a reagent ndi otakata, ndipo ndalama zomwe zimagwiritsidwa ntchito ndi zochepa kuposa njira yopangira chlorine ya alkaline.

• Zoyipa : Njira ya Inco imakhala ndi vuto lopangitsa kuti SCN⁻ ikhale yosungunuka, ndipo SCN⁻ imatha kusokoneza CN⁻ pambuyo pake, kotero siyoyenera kuchiza madzi otayira a cyanide ndi SCN⁻ yochuluka. SO₂ ndi chinthu choipitsa mpweya ndipo chimatha kutuluka ndikutuluka madzi panthawi yochitapo kanthu, zomwe zimaipitsa chilengedwe.

Njira ya H₂O₂ Oxidation

Pansi pa mtengo wa pH wa 9.5 - 11. kutentha kwabwino, ndi ma ions amkuwa (Cu²⁺) monga chothandizira, H₂O₂ imatulutsa cyanide kupanga CNO⁻. CNO⁻ idzapangidwanso hydrolyzed kuti ipange NH₄⁺ ndi CO₃²⁻, ndipo kuchuluka kwa hydrolysis kumadalira pH.

• Ubwino : Mphamvu ya mankhwala a madzi otayira a cyanide ndi yabwino, ndipo njira yake ndi yosavuta. Njira yothira okosijeni ndi yoyenera pochiza madzi otayira a cyanide ochepa, ndipo kuchuluka kwa cyanide pambuyo pa chithandizo kumakhala kochepera 0.5mg/L.

• Zoyipa : H₂O₂ ndi poizoni komanso yowononga, kotero mayendedwe ake ndi kugwiritsidwa ntchito kwake ndi koopsa. Njira yothira okosijeni imakhala ndi vuto lopangitsa kuti SCN⁻ ikhale yosungunuka m'madzi otayidwa, ndipo madzi otayidwa omwe akonzedwa amakhalabe ndi poizoni.

Njira ya Ozone Oxidation

Ozone ili ndi mphamvu yamphamvu kwambiri ya okosijeni, yokhala ndi mphamvu ya elekitirodi ya 2.07mV, yachiwiri pambuyo pa fluorine. Imatha kuwola mosavuta zigawo zomwe sizingawonongeke ndi ma okosijeni ena. Kapangidwe kake kachitidwe ka ozoni oxidation ndikuti ozoni imakumana ndi cyanide kupanga cyanide, yomwe imapangidwa ndi hydrolyzed kuti ipange nayitrogeni ndi carbonate.

• Ubwino : Zimangofunika zida zopangira ozoni ndipo sizifunika kugula ndi kunyamula mankhwala. Njirayi ndi yosavuta komanso yosavuta, yopanda kuipitsa kwina.

• Zoyipa : Chifukwa cha kukwera mtengo kwa majenereta a ozone komanso kuvutika kukonza zida, pali zoletsa zina pakugwiritsa ntchito mafakitale. Njira yothira ozone imagwiritsa ntchito magetsi ambiri, kotero zimakhala zovuta kugwiritsa ntchito m'malo omwe alibe mphamvu zokwanira.

Njira Zochiritsira Zapamwamba - Kuyika kwa Madzi a Cyanide

Njira ya Acidification

Njira ya acidification imatha kuchiza njira zambiri zamtundu wa cyanide (60 × 10⁻⁶ + NaCN) zotulutsidwa m'mafakitale. Kuchuluka kwa ayoni a cyanide aulere mu yankho kumatha kuchepetsedwa kukhala 1 × 10⁻⁶.

• Ubwino : Imatha kubwezeretsa cyanide bwino, kubwezeretsanso zinthu, komanso ili ndi phindu lalikulu pazachuma.

• Zoyipa : Ndalama zomwe zimayikidwa kamodzi kokha ndi zazikulu kwambiri, ndipo mabizinesi ena ang'onoang'ono ndi apakatikati sangakwanitse. Ntchito yake ndi yovuta, ndipo zamkati zomwe zakonzedwazo zikuvutikabe kukwaniritsa miyezo yotulutsira madzi.

Njira Yowonongera Zachilengedwe

Njira yowonongeka kwachilengedwe ndi njira yoyeretsera yomwe imawononga cyanide pogwiritsa ntchito zinthu zachilengedwe monga kuwala. Zimaphatikizapo zotsatira za cyanide volatilization, decomposition, oxidation, photochemical degradation, biodegradation, precipitation, and adsorption, zomwe zimakhala chifukwa cha zovuta zowonongeka za thupi, photochemistry, ndi biochemistry.

• Ubwino : Njira yoyeretsera mwachilengedwe imatha kukwaniritsa cholinga chochotsa cyanide popanda zida kapena mankhwala aliwonse, kotero mtengo wake ndi wotsika kwambiri.

• Zoyipa : Njirayi ndi yochedwa kwambiri, ndipo madzi otayidwa omwe akonzedwa sangakwaniritse miyezo yotulutsira madzi.

Awiri - Njira Yakugwetsa Kwamagawo

Njira ziwiri zoyambira mpweya ndi njira yotsekedwa bwino - kuzungulira kwathunthu - njira yozungulira yopangidwira zomera zazing'ono ndi zazing'ono - zazikulu zagolide za cyanidation zokhala ndi SCN⁻ madzi onyansa, omwe amatha kutulutsa "zero discharge" yamadzi onyansa. Njira ziwiri za mpweya wa siteji zimaphatikizapo kuwonjezera chothandizira ndi mpweya wokwanira ku cyanide m'madzi onyansa, ndiyeno kuchotsa cyanide kudzera muzotsatira zotsatirazi pa golide.

2Cu⁺ + 2SCN⁻→Cu₂(SCN)₂↓

Ca²⁺ + SO₄²⁻→CaSO₄↓

Pb²⁺ + SO₄²⁻→PbSO₄↓

H⁺ + CN⁻→HCN

• Ubwino : Imatha kuchotsa ma ayoni achitsulo cholemera mu yankho ndikupangitsa kuti madzi otayira agwiritsidwenso ntchito.

• Zoyipa : Gawo loyamba la mvula liyenera kukhala lokwanira. Kupanda kutero, powonjezera alkali, cuprous rhodanate idzasungunukanso, zomwe zimakhudza zotsatira za mankhwalawa. CaSO₄ yosagwa ingayambitse kutsekeka kwa valavu.

Izi ndi njira zodziwika bwino zoyeretsera madzi a cyanide muzomera zagolide za cyanidation. Kuphatikiza pa cyanide yomwe ili pamwambapa - njira zochotsera, kuchepetsa kugwiritsa ntchito cyanide mu ndondomeko ya golide ya cyanidation kungathenso kuchepetsa kutuluka kwa madzi onyansa a cyanide.