Maɓallin Maɓalli a cikin Tsarin Leaching na Cyanide: Yadda Suke Shafar Farfaɗowar Zinare

A cikin ma'adinai masana'antu, da cyanidetsarin leaching ya kasance ɗaya daga cikin hanyoyin da aka fi amfani da su don hako zinari daga ma'adinai. Wannan tsari ya dogara ne akan iyawar ions cyanide don samar da hadaddun da aka soluble tare da zinariya, yana ba da damar rabuwa da matrix na ma'adinai. Koyaya, ingancin wannan tsari, musamman ma dawo da zinari, ya dogara sosai akan sigogi masu mahimmanci da yawa. Fahimtar waɗannan sigogi da tasirin su akan dawo da zinariya yana da mahimmanci don inganta tsarin leaching cyanide da tabbatar da ingantaccen tattalin arziki.

Cyanide Concentration

Ƙaddamar da cyanide a cikin maganin leaching shine mahimmancin ma'auni wanda ke tasiri sosai ga dawo da zinariya. A mafi girma maida hankali na cyanide gabaɗaya yana haifar da saurin rushe adadin gwal. Wannan saboda ƙarar ƙwayar cyanide yana samar da ƙarin ions na cyanide da ke samuwa don amsawa da zinari, yana haifar da halayen sinadaran gaba. Alal misali, a cikin tsarin leaching na cyanide na yau da kullum, ƙara yawan ƙwayar cyanide daga 0.05% zuwa 0.1% na iya haifar da karuwa mai mahimmanci a cikin adadin narkar da zinariya. Duk da haka, akwai mafi kyawun maida hankali na cyanide wanda ya wuce wanda ƙarin haɓaka baya haɓaka dawo da gwal daidai gwargwado. Yawan maida hankali na cyanide zai iya haifar da batutuwa da yawa. Da fari dai, yana iya haifar da samuwar halayen da ba a so. Misali, wasu karafa da ke cikin taman, kamar jan karfe, zinc, da iron, na iya mayar da martani da cyanide, suna cinye cyanide da rage samuwar hakar zinare. Abu na biyu, babban adadin cyanide yana haɓaka farashin aikin saboda buƙatar ƙarin reagent na cyanide. Bugu da ƙari, yana haifar da haɗarin muhalli kamar yadda cyanide abu ne mai guba sosai, kuma mafi girma yawan adadin yana buƙatar ƙarin tsaro mai ƙarfi da matakan sarrafa muhalli.

Darajar PH

pH na maganin leaching yana taka muhimmiyar rawa a cikin tsarin leaching na cyanide. Mafi kyawun pH don cyanidation na zinari yawanci jeri daga 9.5 zuwa 11. A wannan kewayon pH na alkaline, cyanide yana wanzuwa galibi a cikin nau'in ions cyanide na kyauta (CN-), waɗanda sune mafi yawan nau'ikan amsawa don rushewar gwal. Kula da pH mai dacewa yana da mahimmanci saboda a cikin yanayin acidic, ana iya samar da iskar hydrogen cyanide (HCN). HCN yana da rauni kuma yana da guba sosai, ba wai kawai yana haifar da babban haɗari na aminci ga ma'aikata ba har ma yana rage yawan adadin cyanide da ake samu don hakar gwal. A gefe guda kuma, idan pH ya yi yawa, toshewar wasu ƙarfe na hydroxides na iya ƙaruwa, wanda zai iya haifar da samuwar hazo da za su iya rufe ɓangarorin zinare, yana hana haɗin gwiwa tsakanin cyanide da zinariya kuma ta haka ne rage yawan dawo da zinariya. Misali, a cikin ma'adinan da ke ɗauke da ƙarfe mai yawa, a ƙimar pH masu girma, haɓakar ƙarfe na hydroxide na iya haifarwa kuma ya rufe barbashi na gwal, yana sa su kasa samun damar cyanide.

Lokacin Leaching

Tsawon lokacin leaching wani muhimmin siga ne wanda ke yin tasiri kai tsaye akan dawo da gwal. Gabaɗaya, yayin da lokacin leaching ya ƙaru, ƙarin zinari yana narkar da kuma ana dawo dasu. Da farko, adadin narkar da zinare yana da sauri da sauri yayin da sabon cyanide yake amsawa da filayen zinare da aka fallasa. Duk da haka, bayan lokaci, adadin hakar gwal yana raguwa a hankali. Wannan saboda yayin da abin ya ci gaba, ɓangarorin gwal suna ƙarami, kuma wurin da ake samu don amsawa yana raguwa. Har ila yau, ƙaddamar da cyanide a cikin maganin yana raguwa yayin da ake cinye shi a cikin amsawa, kuma tarin samfuran amsawa na iya rage saurin amsawa. Alal misali, a cikin rijiyar da aka ƙera leaching na cyanide, yana iya ɗaukar sa'o'i 24 - 48 don cimma babban matakin dawo da zinariya. Amma idan lokacin leaching ya yi guntu, adadi mai yawa na zinariya na iya zama wanda ba a cire shi ba. Sabanin haka, tsawaita lokacin leaching fiye da mafi kyawun ma'ana bazai haifar da karuwa mai yawa a cikin dawo da zinariya ba amma zai kara yawan farashin aiki, kamar amfani da makamashi don tayar da hankali da kuma yin famfo, kuma yana iya haifar da lalacewa na maganin cyanide saboda tsayin daka ga iska da sauran abubuwan muhalli.

Zafin jiki

Hakanan zazzabi na aikin leaching yana rinjayar ƙimar dawo da gwal. Ƙara yawan zafin jiki gabaɗaya yana haɓaka halayen sinadarai tsakanin cyanide da zinare, yana haifar da mafi girman adadin narkar da zinariya. Maɗaukakin yanayin zafi yana ƙara ƙarfin motsa jiki na ƙwayoyin masu amsawa, yana ba su damar yin karo akai-akai kuma tare da ƙarin ƙarfi, don haka haɓaka halayen. Koyaya, tasirin zafin jiki kuma yana ƙarƙashin iyakancewa. A aikace, ana kiyaye yawan zafin jiki a cikin kewayon matsakaici, yawanci a kusa da 20 - 30 ° C. Wannan saboda haɓaka zafin jiki yana buƙatar ƙarin shigarwar makamashi, wanda ke ƙara farashin aiki. Bugu da ƙari, a yanayin zafi mafi girma, rashin daidaituwa na cyanide yana ƙaruwa, yana haifar da asarar cyanide mafi girma ta hanyar evaporation. Bugu da ƙari, yawan zafin jiki na iya haɓaka sake kunna sauran abubuwan da ke cikin ma'adinan, wanda ke haifar da ƙarin halayen gefen da ke cinye cyanide kuma yana rage haɓakar hakar gwal. Alal misali, a cikin wasu ma'adinan da ke dauke da ma'adanai na sulfide, yanayin zafi mai girma zai iya haifar da oxidation na sulfide, wanda ba kawai yana cinye oxygen da cyanide ba amma kuma yana iya haifar da sulfuric acid, wanda zai iya rage pH na maganin leaching kuma ya rushe tsarin cyanidation.

Samun Oxygen

Oxygen wani abu ne mai mahimmanci a cikin leaching cyanide na zinari. Halin da ke tsakanin zinari, cyanide, da oxygen ana iya wakilta ta ta hanyar sinadari mai zuwa: 4Au + 8NaCN + O₂+ 2H₂O → 4Na[Au(CN)₂]+ 4NaOH. Isasshen iskar oxygen yana da mahimmanci don fitar da wannan matakin gaba. A cikin aikin leaching, ana iya shigar da iskar oxygen ta hanyar iska, ko dai ta hanyar kumfa iska ko kuma iskar oxygen mai tsabta a cikin maganin leaching. Matsakaicin canja wurin iskar oxygen zuwa wurin amsawa yana rinjayar adadin narkar da zinariya. Idan samar da iskar oxygen bai isa ba, za a iyakance halayen, kuma adadin dawo da zinari zai ragu. Duk da haka, yawan iskar oxygen kuma yana iya haifar da matsaloli. Misali, a wasu lokuta, yawan iskar oxygen na iya haifar da iskar shaka na cyanide zuwa cyanate (CNO⁻) ko wasu mafi girma - oxidation - mahadi na jihar, rage yawan adadin cyanide da ake samu don hakar gwal. Bugu da ƙari, a cikin ma'adinan da ke ɗauke da wasu nau'o'in ma'adanai na sulfide, yawan iskar oxygen na iya haifar da oxidation na sulfides, wanda zai iya haifar da sulfuric acid da sauran - samfurori waɗanda zasu iya tsoma baki tare da tsarin cyanidation.

A ƙarshe, tsarin leaching na cyanide don hakar gwal wani tsari ne mai rikitarwa wanda ke tasiri ta hanyar maɓalli masu yawa. Matsakaicin Cyanide, ƙimar pH, lokacin leaching, zafin jiki, da wadatar iskar oxygen duk suna hulɗa don tantance ingancin dawo da gwal. Masu aikin hakar ma'adinai suna buƙatar haɓaka waɗannan sigogi a hankali bisa halayen ma'adinai da ake sarrafa su. Ta hanyar sarrafa waɗannan abubuwan daidai gwargwado, yana yiwuwa a ƙara girman dawo da zinari yayin da rage farashi da tasirin muhalli, tabbatar da dorewar ayyukan hakar gwal na dogon lokaci.p