Nri Sodium Cyanide na Mwepụta ọla edo kọwara

N'ime usoro mwepụta ọlaedo site na ngwakọta cyanide, a na-aṅụ sodium cyanide n'ọtụtụ ụzọ. Sodium cyanide bụ ihe a na-ejikarị ewepụ ọlaedo, n'echiche, naanị gram 0.5 nke Sodium Cyanide ka achọrọ iji chụpụta gram 1 nke ọlaedo. Agbanyeghị, n'ọtụtụ osisi cyanide ọlaedo, oriri cyanide n'ezie dị elu nke ukwuu, na-agafekarị mgbakọta echiche site na ugboro 50 ruo 100.

Isi ihe ndị na-eme ka a na-aṅụ cyanide nke ọma n'usoro cyanidation ọlaedo gụnyere:

1. Oriri nke Cyanide na Usoro Mgbasa ọla edo

Osisi Cyanide ejirila sodium cyanide gbazee ọlaedo site na ọla iji nweta ọlaedo site na mmiri mmiri. Mmeghachi omume kemịkalụ dị na ya bụ ndị a:

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

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

Site na mmeghachi omume electrochemical, a maara na ịgbari gram ọla edo chọrọ 1 grams nke sodium cyanide.

2. Oriri nke Cyanide na mmeghachi omume na Associated Base Metals

(1) Ụfọdụ ọla edo nwere mineral ndị metụtara ya dịka pyrite, magnetite, chalcopyrite, sulfate minerals, hydroxides, na oxides. N'oge a na-egwepịa ya, a na-emepụta ntụ ígwè, nke na-emeghachi omume nwayọ nwayọ na sodium cyanide, na-eme ka oriri cyanide dịkwuo elu . Mmeghachi omume ndị a bụ ndị a:

• [FeS2+NaCN→FeS+NaCNS]

• [Fe(OH)2+2NaCN→Fe(CN)2+2NaOH]

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

• [S+NaCN→NaCNS]

(2) Ọ bụrụ na ọla edo nwere ụdị ọla kọpa dị iche iche, ha ga-emeghachikwa omume na sodium cyanide iji mepụta ogige cyanide ọla kọpa, na-eri cyanide na usoro ahụ. Mmeghachi omume ndị a bụ:

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

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

N'ihi mmeghachi omume siri ike nke sodium cyanide nwere ọtụtụ mineral ọla kọpa, n'ozuzu, a chọrọ 2.3 ruo 3.4 grams nke cyanide iji gbarie gram ọla kọpa.

(3) Ọ bụrụ na ọla edo mbụ ahụ nwere sphalerite ma ọ bụ smithsonite, ha ga-ejikwa sodium cyanide meghachi omume iji mepụta zinc cyanide na carbonates. Mmeghachi omume ndị a bụ:

• [ZnS+4NaCN→Na2[Zn(CN)4]+Na2S]

• [ ZnCO3+4NaCN→Na2Zn(CN)4+Na2CO3]

(4) Ọ bụrụ na ọla edo nwere arsenopyrite, mercury, selenium, tellurium, wdg, ha ga-emeghachi omume na sodium cyanide. Mgbe ahụ ore nwere nkume carbonaceous, karịsịa ndị bara ụba na carbon organic, adsorption nke cyanide na-esiwanye ike, na-eme ka cyanide leaching nke ọla edo sie ike karị.

3. Hydrolysis nke Cyanides

N'ime mmiri, cyanides na-enweta oke hydrolysis dị iche iche dabere na pH, yana ọnụọgụ hydrogen cyanide emepụtara na alkalinity nke mmiri ahụ. Enwere ike igosi mmeghachi omume ahụ dị ka ndị a:

• [NaCN + H2O → NaOH + HCN↑]

• [CN⁻ + 2H2O → HCOO⁻ + NH3]

Mgbe hydrolysis gasịrị, akụkụ nke cyanide na-emepụta hydrogen cyanide, ebe akụkụ ọzọ na-eme ka oxidatively hydrolyzed, jiri nwayọọ nwayọọ na-emepụta formic acid na amonia. Na 100°C, CN⁻ na-atụfu 50%, na 130°C, ọ na-atụfu 85%.

N'ime usoro cyanidation maka igwu ọla edo, hydrogen cyanide bụ gas na-egbu egbu nke ukwuu. Ọ bụrụ na ejighị ya nke ọma, ọ nwere ike ibute ịba ụba nke NaCN, na-ebuli ọnụ ahịa mmepụta ihe, na ịkpata mmetọ gburugburu ebe obibi, yana itinye ihe ize ndụ ahụike nye ndị ọrụ. Ọnụ ego nke HCN mepụtara dịgasị iche na pH nke ngwọta: na pH 10.5. naanị 6.1% nke hydrogen cyanide na-emepụta; na pH 10. ọ na-abawanye ruo 17%; na pH 9.5. ọ ruru 39.2%; na pH 9.0. bụ 67.1%. Ya mere, na osisi CIP gold (Carbon-in-Pulp), a na-edozi pH n'etiti 11 na 12 iji chịkwaa hydrolysis nke cyanides.

4. The oxidation nke cyanide (CN-) site etisasịwo oxygen (O2)

Iji welie mgbasa nke ọla edo, ma CN- na O2 ga-etinyerịrị aka na mmeghachi omume ahụ. N'ime ụlọ okpomọkụ na nrụgide, ihe kachasị solubility nke oxygen bụ 8.2 mg / L. Mgbakwunye nke onye na-ahụ maka oxidizing siri ike nwere ike ime ka ntinye nke oxygen na ngwọta ya dịkwuo elu, na-eme ka usoro nkwụsị ahụ dịkwuo ngwa ngwa. Otú ọ dị, ọnụ ọgụgụ nke oxygen na cyanide ga-edozirịrị; ma ọ bụghị ya, ọnụ ọgụgụ leaching nwere ike ibelata. oxygen gbazere na-emeghachi omume na cyanide iji mepụta cyanate, nke kwụsiri ike na ngwọta alkaline. Otú ọ dị, na pH dị ala karịa 7. ọ na-emepụta amonia na bicarbonate. Nha nhata mmeghachi omume bụ ndị a:

• [1/2 O2 + CN– → (CNO)–]

• [(CNO)– + 2 H2O → HCO3– + NH3]

Ya mere, mmeghachi omume a nwere ike iduga oriri cyanide n'oge usoro leaching ma ọ bụ electrolysis.

5. Adsorption nke Cyanide site na Clay

N'oge usoro cyanidation, ígwè sulfide na ore na-emepụta iron hydroxide, ebe silicates na ore na-emepụta colloidal silica na alkaline ọkara. Ihe abụọ ndị a nwere ikike nke ịgbasa cyanide, na-eduga na mfu nke cyanide yana ihe fọdụrụ na leaching.

6. Nri nke cyanide site na ihe ndị ọzọ

(1) Mgbe slurry na-akpali ma jupụta na ikuku, CO2 ga-adị na ngwọta. CO2 ga-emeghachi omume na cyanide.

• [2NaCN+CO2+H2O→Na2CO3+2HCN↑]

(2) Sulfide mineral dị ka pyrite na mbụ ore na-emeghachi omume na etisasịwo oxygen (O2) na ore pulp, na sulfites na sulfates pụta ga-emeghachi omume na cyanide.

• [FeS+2O2→FeSO4]

• [FeSO4+6NaCN→Na4Fe(CN)6+Na2SO4]

Enwere ike ịgbakwunye obere obere CaO ma ọ bụ Ca (OH) 2 tupu ịsa ahụ iji wepụ acid ahụ ma gbochie mmeghachi omume dị n'elu ime.

na ngwụcha

Ihe dị n'elu bụ akụkụ 6 nke oriri cyanide na usoro cyanidation ọla edo. Na mgbakwunye na cyanide achọrọ maka ịgbasa ọla edo nkịtị, enwere ọtụtụ oriri na-adịghị mkpa, dị ka anyị mmeghachi omume na mineral ndị ọzọ metụtara, onwe-hydrolysis, wdg. 

Ọ bụrụ na ị nwere ajụjụ ọ bụla gbasara ọdịnaya dị n'elu, ma ọ bụ chọọ ịma , ị nwere ike ịkpọtụrụ ndị ahịa n'ịntanetị ma ọ bụ nyefee ozi, anyị ga-akpọtụrụ gị ozugbo enwere ike!