Amfanin Sodium Cyanide a cikin Haɗin Zinare An Bayyana

A cikin aikin hako zinari daga mahadi na cyanide. Sodium cyanide ana cinye ta hanyoyi da yawa. Sodium cyanide shine mafi yawan amfani leaching wakili a cikin hakar zinariya, kuma a ka'idar, kawai 0.5 grams na sodium Cyanide ana buƙatar don leach gram 1 na zinariya. Duk da haka, a yawancin tsire-tsire na cyanidation na zinari, ainihin amfani da cyanide yana da girma sosai, sau da yawa ya wuce ƙididdiga na ka'idar sau 50 zuwa 100.

Babban abubuwan da ke haifar da yawan amfani da cyanide a cikin zinariya cyanidation tsari sun hada da:

1. Amfani da Cyanide a cikin Tsarin Rushe Zinare

An yi amfani da tsire-tsire na Cyanide sodium cyanide don narkar da zinari daga tama domin a kwato zinare daga leda. Abubuwan sinadaran da ke tattare da su sune kamar haka:

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

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

Daga halayen electrochemical, an san cewa narkar da gram 1 na zinariya yana buƙatar amfani da 0.92 grams na sodium cyanide.

2. Yin amfani da Cyanide a cikin Haɗin kai tare da Ƙarfa na Ƙarƙashin Ƙarfafawa

(1) Wasu ma'adanai na zinariya sun ƙunshi ma'adanai masu alaƙa kamar pyrite, magnetite, chalcopyrite, ma'adinan sulfate, hydroxides, da oxides. A lokacin mataki na murkushe, an samar da foda na baƙin ƙarfe, wanda sannu a hankali ya amsa tare da cyanide sodium, yana ƙaruwa amfani da cyanide. Abubuwan da suka faru sune kamar haka:

• [FES2+NaCN→FeS+NaCNS]

• [Fe(OH)2+2NaCN→Fe(CN)2+2NaOH]

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

• [S+NaCN→NaCNS]

(2) Idan ma'adinan zinare ya ƙunshi nau'ikan ma'adanai na tagulla daban-daban, za su kuma yi da sodium cyanide don samar da rukunin cyanide na jan karfe, suna cinye cyanide a cikin tsari. Abubuwan da suka faru sune kamar haka:

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

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

Saboda karfi reactivity na sodium cyanide tare da yawa jan karfe ma'adanai, kullum, 2.3 zuwa 3.4 grams na cyanide ake bukata don narkar da 1 gram na jan karfe.

(3) Idan asalin gwal ɗin ya ƙunshi sphalerite ko smithsonite, za su kuma amsa da sodium cyanide don samar da zinc cyanide da carbonates. Abubuwan da suka faru sune kamar haka:

• [ZnS+4NaCN→Na2[Zn(CN)4]+Na2S]

• [ ZnCO3+4NaCN→Na2Zn(CN)4+Na2CO3]

(4) Idan ma'adinan zinare ya ƙunshi arsenopyrite, mercury, selenium, tellurium, da dai sauransu, za su kuma mayar da martani da sodium cyanide. Lokacin da jikin tama ya ƙunshi duwatsun carbonaceous, musamman waɗanda ke da wadataccen carbon carbon, adsorption na cyanide ya zama mai ƙarfi, yana sa ƙwayar cyanide na zinare ya fi wahala.

3. Hydrolysis na Cyanide

A cikin bayani, cyanides sha daban-daban matakan hydrolysis dangane da pH, tare da adadin hydrogen cyanide samar da alaka da alkalinity na bayani. Ana iya wakilta martanin kamar haka:

• [NaCN + H2O → NaOH + HCN↑]

• [CN⁻ + 2H2O → HCOO⁻ + NH3]

Bayan hydrolysis, wani yanki na cyanide yana haifar da hydrogen cyanide, yayin da wani sashi kuma yana samar da ruwa mai oxidatively, a hankali yana samar da formic acid da ammonia. A 100°C, CN⁻ ya yi hasarar 50%, kuma a 130°C, ya rasa 85%.

A cikin tsarin cyanidation don hakar gwal, hydrogen cyanide gas ne mai guba sosai. Idan ba a kula da shi yadda ya kamata ba, hakan na iya haifar da karuwar amfani da NaCN, da kara tsadar kayayyaki, da haifar da gurbatar muhalli, tare da haifar da illa ga lafiya ga masu aiki. Adadin HCN da aka samar ya bambanta da pH na maganin: a pH 10.5. kawai 6.1% na hydrogen cyanide aka samar; a pH 10. yana ƙaruwa zuwa 17%; da pH 9.5. ya kai 39.2%; da pH 9.0. ya canza zuwa +67.1%. Sabili da haka, a cikin tsire-tsire na CIP (Carbon-in-Pulp), pH yawanci ana daidaita shi zuwa tsakanin 11 da 12 don sarrafa hydrolysis na cyanides.

4. A oxidation na cyanide (CN-) ta narkar da oxygen (O2)

Don haɓaka adadin narkar da gwal, duka CN- da O2 dole ne su shiga cikin aikin. A dakin da zafin jiki da matsa lamba, matsakaicin solubility na oxygen shine 8.2 mg / L. Bugu da ƙari na wakili mai ƙarfi mai ƙarfi zai iya ƙara yawan iskar oxygen a cikin maganin, yana hanzarta aiwatar da aikin leaching. Duk da haka, dole ne a daidaita rabon oxygen zuwa cyanide; in ba haka ba, yawan leaching na iya raguwa. Narkar da iskar oxygen yana amsawa tare da cyanide don samar da cyanate, wanda ya tsaya a cikin maganin alkaline. Duk da haka, a wani pH kasa da 7. shi hydrolyzes don samar da ammonia da bicarbonate. Matsalolin amsawa sune kamar haka:

• [1/2 O2 + CN– → (CNO)–]

• [(CNO) – + 2 H2O → HCO3 – + NH3]

Sabili da haka, wannan halayen na iya haifar da amfani da cyanide a lokacin leaching ko hanyoyin lantarki.

5. Adsorption na Cyanide ta Clay

A lokacin aikin cyanidation, baƙin ƙarfe sulfide a cikin tama yana haifar da baƙin ƙarfe hydroxide, yayin da silicates a cikin tama suna samar da silica colloidal a cikin matsakaici na alkaline. Duk waɗannan abubuwa biyu suna da takamaiman ƙarfin da za su iya haɓaka cyanide, wanda ke haifar da asarar cyanide tare da ragowar leaching.

6. Amfani da cyanide ta wasu abubuwa

(1) Lokacin da slurry ya motsa kuma ya cika da iska, CO2 zai kasance a cikin maganin. CO2 kuma za ta mayar da martani da cyanide.

• [2NaCN+CO2+H2O→Na2CO3+2HCN↑]

(2) Ma'adinan Sulfide kamar pyrite a cikin ma'adanin asali suna amsawa tare da narkar da iskar oxygen (O2) a cikin ƙwayar tama, kuma sakamakon sulfites da sulfates za su yi amsa tare da cyanide.

• [FeS+2O2→FeSO4]

• [FeSO4+6NaCN→Na4Fe(CN)6+Na2SO4]

Ana iya ƙara ƙaramin adadin CaO ko Ca (OH) 2 kafin yin leaching don kawar da acid kuma hana abin da ke sama daga faruwa.

a ƙarshe

Abubuwan da ke sama sune abubuwan 6 na amfani da cyanide a cikin tsarin aikin cyanidation na zinariya. Baya ga cyanide da ake buƙata don narkar da zinari na al'ada, akwai yawancin abubuwan amfani da ba su da mahimmanci, irin mu mu amsa tare da sauran ma'adanai masu alaƙa, kai-hydrolysis, da dai sauransu. 

Idan kuna da wasu tambayoyi game da abubuwan da ke sama, ko kuna son sanin , kuna iya tuntuɓar sabis na abokin ciniki na kan layi ko aika saƙo, za mu tuntuɓe ku da wuri-wuri!