Kugwiritsiridwa ntchito kwa Sodium Cyanide mu Kutulutsa Golide Kufotokozedwa

Pochotsa golide kuzinthu za cyanide, Sodium cyanide amadyedwa m'njira zingapo. Sodium cyanide ndiyomwe imagwiritsidwa ntchito kwambiri leaching agent m'zigawo za golide, ndipo mwachidziwitso, magalamu 0.5 okha a Sodium Cyanide amafunikira 1 gramu ya golidi. Komabe, m'zomera zambiri zopangira golide, kumwa kwenikweni kwa cyanide kumakhala kokwera kwambiri, nthawi zambiri kumapitilira kuwerengetsa mongoyerekeza ndi nthawi 50 mpaka 100.

Zinthu zazikulu zomwe zimapangitsa kuti cyanide azigwiritsidwa ntchito kwambiri golide cyanidation ndondomeko monga:

1. Kugwiritsa ntchito Cyanide mu Njira Yowonongeka kwa Golide

Zomera za cyanide zakhala zikugwiritsidwa ntchito sodium cyanide Kusungunula golidi kuchokera ku miyala kuti atenge golide ku leachate. Zotsatira za chemical zomwe zikukhudzidwa ndi izi:

• [2Au+4NaCN+O2+2H2O→2Na[Au(CN)2]+2NaOH+H2O2]

• [ 2Au+4NaCN+H2O2→2Na[Au(CN)2]+2NaOH]

Kuchokera pamachitidwe a electrochemical, zimadziwika kuti kusungunula 1 gramu ya golide kumafuna kumwa 0.92 magalamu a sodium cyanide.

2. Kugwiritsa ntchito Cyanide mu Reactions ndi Associated Base Metals

(1) Mafuta ena a golide ali ndi mchere wogwirizana monga pyrite, magnetite, chalcopyrite, mchere wa sulfate, hydroxides, ndi oxides. Panthawi yophwanyidwa, ufa wachitsulo umapangidwa, womwe umakhudzidwa pang'onopang'ono ndi sodium cyanide, kuwonjezeka kugwiritsa ntchito cyanide. Zotsatira zake ndi izi:

• [ FeS2+NaCN→FeS+NaCNS]

• [ Fe(OH)2+2NaCN→Fe(CN)2+2NaOH]

• [ Fe+6NaCN+2H2O→Na4Fe(CN)6+2NaOH+H2↑]

• [S+NaCN→NaCNS]

(2) Ngati miyala ya golide ili ndi mitundu yosiyanasiyana ya mchere wamkuwa, adzachitanso ndi sodium cyanide kuti apange copper cyanide complexes, kudya cyanide panthawiyi. Zotsatira zake ndi izi:

• [ 2CuSO4+4NaCN→Cu2(CN)2+2Na2SO4+(CN)2↑]

• [ 2Cu2S+4NaCN+2H2O+O2→Cu2(CN)2+Cu2(CNS)2+4NaOH]

Chifukwa champhamvu ya sodium cyanide yokhala ndi mchere wambiri wamkuwa, nthawi zambiri, 2.3 mpaka 3.4 magalamu a cyanide amafunikira kusungunula 1 gramu yamkuwa.

(3) Ngati golide woyambirira ali ndi sphalerite kapena smithsonite, adzachitanso ndi sodium cyanide kupanga zinc cyanide ndi carbonates. Zotsatira zake ndi izi:

• [ ZnS+4NaCN→Na2[Zn(CN)4]+Na2S]

• [ ZnCO3+4NaCN→Na2Zn(CN)4+Na2CO3]

(4) Ngati miyala ya golide ili ndi arsenopyrite, mercury, selenium, tellurium, etc., adzachitanso ndi sodium cyanide. Thupi la ore likakhala ndi miyala ya carbonaceous, makamaka yomwe ili ndi carbon organic carbon, kutsekemera kwa cyanide kumakhala kolimba, zomwe zimapangitsa kuti golide wa cyanide ukhale wovuta kwambiri.

3. Hydrolysis ya Cyanides

Mu yankho, cyanides amadutsa mosiyanasiyana hydrolysis kutengera pH, ndi kuchuluka kwa haidrojeni cyanide opangidwa kukhala zogwirizana ndi alkalinity wa yankho. Zomwe zimachitika zitha kuyimiridwa motere:

• [NaCN + H2O → NaOH + HCN↑]

• [CN⁻ + 2H2O → HCOO⁻ + NH3]

Pambuyo pa hydrolysis, gawo lina la cyanide limapanga haidrojeni cyanide, pamene gawo lina ndi oxidatively hydrolyzed, pang'onopang'ono kupanga formic acid ndi ammonia. Pa 100 ° C, CN⁻ imataya 50%, ndipo pa 130 ° C, imataya 85%.

Mu njira yopangira migodi ya golide, hydrogen cyanide ndi mpweya wapoizoni kwambiri. Ngati sizikuyendetsedwa bwino, zitha kuyambitsa kugwiritsa ntchito NaCN, kukweza mtengo wopangira, ndikuwononga chilengedwe, komanso kuyika chiwopsezo chaumoyo kwa ogwira ntchito. Kuchuluka kwa HCN komwe kumapangidwa kumasiyanasiyana ndi pH ya yankho: pa pH 10.5. 6.1% yokha ya hydrogen cyanide imapangidwa; pa pH 10. imawonjezeka kufika 17%; pH 9.5. amafika 39.2%; ndi pH 9.0. ndi 67.1%. Chifukwa chake, muzomera zagolide za CIP (Carbon-in-Pulp), pH nthawi zambiri imasinthidwa kukhala pakati pa 11 ndi 12 kuwongolera hydrolysis ya ma cyanides.

4. The okosijeni wa cyanide (CN-) ndi kusungunuka mpweya (O2)

Kupititsa patsogolo kusungunuka kwa golide, onse a CN- ndi O2 ayenera kutenga nawo mbali pakuchita. Pa kutentha ndi kupanikizika, mpweya wosungunuka kwambiri ndi 8.2 mg/L. Kuphatikizika kwa oxidizing amphamvu kumatha kuwonjezera kuchuluka kwa okosijeni mu yankho, kufulumizitsa kwambiri njira ya leaching. Komabe, chiŵerengero cha okosijeni ndi cyanide chiyenera kukhala choyenera; Apo ayi, mlingo wa leaching akhoza kuchepa. Mpweya wosungunuka umakhudzidwa ndi cyanide kupanga cyanate, yomwe imakhala yosasunthika muzitsulo za alkaline. Komabe, pa pH yotsika kuposa 7. imasungunuka kuti ipange ammonia ndi bicarbonate. Ma reaction equations ndi awa:

• [1/2 O2 + CN– → (CNO)–]

• [(CNO)– + 2 H2O → HCO3– + NH3]

Chifukwa chake, izi zitha kupangitsa kuti cyanide amwe panthawi ya leaching kapena electrolysis.

5. Adsorption ya Cyanide ndi Clay

Pa cyanidation ndondomeko, chitsulo sulfide mu ore amapanga chitsulo hydroxide, pamene silicates mu ore kupanga colloidal silika mu alkaline sing'anga. Zonse ziwirizi zimakhala ndi mphamvu yotsatsa cyanide, zomwe zimapangitsa kuti cyanide iwonongeke pamodzi ndi zotsalira za leaching.

6. Kugwiritsa ntchito cyanide ndi zinthu zina

(1) Pamene slurry ikugwedezeka ndikudzazidwa ndi mpweya, CO2 idzakhala mu yankho. CO2 idzachitanso ndi cyanide.

• [2NaCN+CO2+H2O→Na2CO3+2HCN↑]

(2) Mchere wa sulfide monga pyrite mu ore wapachiyambi amachitira ndi mpweya wosungunuka (O2) mu zamkati za ore, ndipo sulfite ndi sulfate zomwe zimatsatira zidzachitanso ndi cyanide.

• [FeS+2O2→FeSO4]

• [FeSO4+6NaCN→Na4Fe(CN)6+Na2SO4]

Kuchepa kwa CaO kapena Ca (OH) 2 kumatha kuwonjezeredwa musanawonjezeke kuti muchepetse asidi ndikuletsa zomwe zili pamwambapa kuti zisachitike.

Pomaliza

Zomwe zili pamwambazi ndizinthu 6 zogwiritsira ntchito cyanide mu ndondomeko ya golide ya cyanidation. Kuphatikiza pa cyanide yofunikira pakusungunuka kwa golide wamba, pali zinthu zambiri zosafunikira, monga momwe timachitira ndi mchere wina wokhudzana, kudzipangira hydrolysis, ndi zina zambiri. 

Ngati muli ndi mafunso okhudza zomwe zili pamwambapa, kapena mukufuna kudziwa, mutha kufunsa makasitomala pa intaneti kapena kutumiza uthenga, tidzakulumikizani posachedwa!