Bincike kan Ra'ayin Tsakanin Sulfide na Azurfa da Sodium Cyanide

1. Gabatarwa

Halin da ke tsakanin Azurfa sulfide ((Ag_2S \)) da Sodium cyanide (\(NaCN \)) yana da tasiri mai mahimmanci a fagage daban-daban, musamman wajen fitar da azurfa daga ma'adinan sa. Fahimtar wannan martani yana da mahimmanci don haɓaka hanyoyin masana'antu da kuma zurfin fahimtar daidaiton sinadarai da motsin motsi a cikin sarƙaƙƙiya tsarin.

2. Ka'idojin amsawa

2.1 Daidaiton Sinadarai

A dauki tsakanin azurfa sulfide da sodium Cyanide za a iya wakilta

b ma'aunin sinadarai mai zuwa a gaban iska:\(2Ag_2S + 8NaCN + O_2 + 2H_2O = 4Na[Ag(CN)_2] + 4NaOH + 2S\)

A cikin wannan yanayin, sulfide na azurfa yana amsawa da sodium cyanide. Azurfa a cikin azurfa sulfide ya zama hadadden ion, azurfa cyanide hadadden ion \([Ag(CN)_2]^{-} \), yayin da sulfur a cikin azurfa sulfide aka oxidized zuwa elemental sulfur. Oxygen a cikin iska yana shiga cikin amsawa, yana aiki a matsayin wakili na oxidizing.

2.2 Complex ion Formation

Azurfa yana da ƙaƙƙarfan hali don samar da hadaddun ions tare da ions cyanide. Samuwar \([Ag(CN)_2]^{-} Matsakaicin ma'auni don samuwar \([Ag(CN)_2]^{-} \) yana da girma sosai, wanda ke nufin cewa amsawar ions na azurfa tare da ions cyanide don samar da wannan hadaddun yana da kyau sosai. Hadadden ion \ ([Ag(CN)_2]^{-}\) ya fi narkewa a cikin ruwa idan aka kwatanta da sulfide na azurfa, wanda ba ya narkewa. Wannan bambance-bambancen narkewa shine maɓalli mai mahimmanci a cikin tsarin ɗaukar hoto gabaɗaya.

2.3 Oxidation na Sulfur

Sulfur a cikin azurfa sulfide yana cikin yanayin oxidation -2. A lokacin dauki tare da sodium cyanide a gaban iska, sulfur ne oxidized. Oxygen daga iska yana ba da ikon oxidizing. Rashin iskar oxygen na sulfur daga -2 zuwa 0 (sulfur elemental) wani muhimmin sashi ne na tsarin amsawa. Hanyar amsawa don hadawan abu da iskar shaka na sulfur ya ƙunshi jerin electron - matakan canja wuri, waɗanda ke da alaƙa da haɗin kai gabaɗaya da haɓakar samfuran.

3. Yanayin Amsa

3.1 La'akari da Thermodynamic

Thermodynamically, da kai tsaye dauki na azurfa sulfide tare da sodium cyanide ba tare da kasancewar wani oxidizing wakili kamar iska yana da tabbatacce Gibbs free makamashi canji (\(\Delta G>0 \)). Wannan yana nuna cewa amsawar ba ta tashi ba ne a ƙarƙashin daidaitattun yanayi. Matsakaicin ma'auni (\(K \)) don amsawar \(Ag_2S + 4NaCN\rightleftharpoons 2Na[Ag(CN)_2]+Na_2S \) kadan ne. Koyaya, lokacin da aka gabatar da iskar oxygen, yanayin gabaɗayan ya zama na kwatsam. Rashin iskar oxygen na sulfur ta hanyar iskar oxygen yana ba da ƙarfin motsa jiki don shawo kan rashin jin daɗi na farkon dauki tsakanin sulfide na azurfa da sodium cyanide.

3.2 Abubuwan Bukatun Tattara

Domin amsawar ta ci gaba da kyau, ana buƙatar isassun taro na sodium cyanide. Tun da azurfa sulfide ba shi da narkewa a cikin ruwa, ana buƙatar babban taro na ions cyanide don hadaddun tare da ions na azurfa waɗanda a hankali aka saki daga sulfide na azurfa. Lissafi sun nuna cewa don \ (0.1mol \) na \ (Ag_2S \) don narkewa a cikin \ (1L \) na \ (NaCN \) bayani, mafi ƙarancin maida hankali na \ (NaCN \) da ake buƙata shine kusan \ (12.97mol / L \). Wannan babban abin da ake buƙata na maida hankali shine saboda ƙarancin solubility na sulfide na azurfa da buƙatar matsawa ma'auni na hadaddun - haɓakar haɓakawa zuwa ga samuwar azurfa - cyanide complex ion.

3.3 Zazzabi da Matsi

Ko da yake abin da ya faru tsakanin sulfide na azurfa da sodium cyanide na iya faruwa a cikin dakin da zafin jiki, karuwa a zafin jiki na iya ƙara yawan yawan dauki. Maɗaukakin yanayin zafi yana ƙara ƙarfin motsa jiki na ƙwayoyin masu amsawa, wanda ke haifar da ƙarin haɗuwa da kuzari. Duk da haka, matsanancin zafin jiki na iya haifar da halayen gefe, kamar ruɓar mahadi na cyanide. Matsi ba shi da wani tasiri mai mahimmanci kai tsaye ga wannan amsa a ƙarƙashin yanayi na al'ada, kamar yadda yake amsawa a cikin wani bayani mai ruwa da ruwa ba gas ba - yanayin lokaci inda canje-canjen matsin lamba zai yi tasiri sosai.

4. Reaction Kinetics

4.1 Ƙayyadaddun Ƙimar Maɗaukaki

Ana iya ƙayyade ƙimar sulfide na azurfa tare da sodium cyanide ta hanyoyin gwaji. Ta hanyar auna canji a cikin maida hankali na masu amsawa (kamar sulfide na azurfa ko sodium cyanide) ko samfuran (kamar azurfa - cyanide complex ion ko sulfur) akan lokaci, ana iya ƙididdige ƙimar amsawa. Alal misali, a cikin gwajin reactor na batch, ana iya ɗaukar samfurori a lokaci-lokaci, kuma za'a iya auna ma'auni na azurfa - cyanide complexion a cikin maganin ta amfani da fasaha na nazari irin su spectrophotometry ko ion - electrodes masu zaɓi. Adadin samuwar azurfa - cyanide hadaddun ion ana amfani da shi don ƙididdige ƙimar amsawar gabaɗaya.

4.2 Rate - Ƙayyade Matakai

Hanyar amsawa na cyanidation sulfide na azurfa yana da rikitarwa kuma ya ƙunshi matakai da yawa. Matsakaicin ƙididdige matakin ƙila shine mafi ƙarancin mataki a cikin jerin martani. Ɗaya daga cikin mahimman matakai shine narkar da sulfide na azurfa, wanda ya haɗa da sakin ions na azurfa da sulfur ions. Haɗin ions na azurfa tare da ions cyanide yana da sauri idan aka kwatanta da narkar da sulfide na azurfa. Rashin iskar oxygen na sulfur ta hanyar iskar oxygen kuma yana taka muhimmiyar rawa a cikin yawan amsawar gabaɗaya. Idan samar da iskar oxygen yana da iyaka, zai iya zama ƙima - ƙididdiga factor. Bugu da kari, yaduwar kwayoyin reactant (kamar cyanide ions da oxygen) zuwa saman tarkacen sulfide na azurfa kuma na iya shafar adadin dauki, musamman a lokuta inda girman kwayar sulfide na azurfa ya girma.

4.3 Samfuran Lissafi

An ƙirƙira ƙirar lissafin lissafi don bayyana halayen halayen sinadarai na sulfide na azurfa. Ɗayan samfurin da aka saba amfani da shi shine ƙirar ƙira - core. Wannan samfurin yana ɗauka cewa abin da ya faru yana faruwa a saman tsayayyen barbashi na sulfide na azurfa, kuma yayin da martanin ya ci gaba, ainihin tushen sulfide na azurfa wanda ba a yi shi ba yana raguwa. Samfurin yana yin la'akari da dalilai kamar watsawar masu amsawa ta hanyar samfurin samfurin (sulfur da sauran samfuran amsawa waɗanda zasu iya tasowa a saman ɓangarorin sulfide na azurfa), ƙimar amsawar sinadarai a saman, da ma'auni mai rikitarwa a cikin lokacin bayani. Ta amfani da wannan ƙirar, ana iya yin tsinkaya game da ƙimar amsawa a ƙarƙashin yanayi daban-daban, kamar bambancin yawan adadin sodium cyanide da oxygen, girman barbashi na sulfide na azurfa, da zafin jiki. Sakamakon gwaji gabaɗaya an gano yana da ingantacciyar yarjejeniya tare da tsinkayar irin waɗannan ƙirar lissafi.

5. Aikace-aikace

5.1 Cire Azurfa daga Ores

Halin da ke tsakanin sulfide na azurfa da sodium cyanide ana amfani dashi sosai a cikin masana'antar hakar ma'adinai don hakar azurfa daga ma'adinan sulfide. A cikin tsari na cyanidation na yau da kullun, azurfar da aka murƙushe - ana bi da tama mai ɗaukar nauyi tare da dilution bayani na sodium cyanide. Sulfide na azurfa a cikin ma'adinai yana amsawa tare da sodium cyanide don samar da azurfa mai narkewa - hadaddun cyanide. Bayan amsawa, maganin da ke dauke da azurfa - cyanide hadaddun ya rabu da ragowar ragowar. Ana iya dawo da azurfar daga maganin ta hanyoyi daban-daban, kamar raguwa tare da wakili mai ragewa (misali, ƙurar zinc). Wannan tsari yana da inganci sosai kuma yana ɗaya daga cikin hanyoyin da aka fi amfani da su don manyan sikelin Hakar Azurfa.

5.2 Tunanin Muhalli

Duk da haka, yin amfani da sodium cyanide a cikin aikin hakar azurfa yana haifar da matsalolin muhalli. Cyanide abu ne mai guba sosai, kuma duk wani ɗigowa ko zubar da bai dace na cyanide ba - wanda ke ɗauke da mafita na iya yin mummunan tasirin muhalli. Sabili da haka, ana aiwatar da tsauraran ƙa'idodin muhalli don tabbatar da amintaccen kulawa da zubar da cyanide a cikin masana'antar hakar ma'adinai. Yawancin kamfanonin hakar ma'adinai kuma suna haɓaka wasu hanyoyin da za su rage amfani da cyanide ko don magance cyanide - mai ɗauke da sharar gida yadda ya kamata. Duk da waɗannan ƙalubalen, abin da ya faru tsakanin sulfide na azurfa da sodium cyanide ya kasance muhimmin tsari a cikin masana'antar hakar azurfa saboda babban ingancinsa na hakar azurfa.

6. Kammalawa

Halin da ke tsakanin sulfide na azurfa da sodium cyanide wani tsari ne mai rikitarwa tare da aikace-aikace masu mahimmanci a cikin hakar azurfa. Fahimtar ƙa'idodin amsawa, yanayi, motsin motsa jiki, da aikace-aikace suna da mahimmanci don haɓaka hanyoyin masana'antu da magance matsalolin muhalli masu alaƙa da amfani da cyanide. Ƙarin bincike a cikin wannan yanki na iya mayar da hankali kan haɓaka ingantaccen yanayin amsawa, inganta zaɓin amsawa, da kuma gano wasu hanyoyin da za a maye gurbin ko rage amfani da cyanide a cikin hakar azurfa.