Ngā Tikanga mō te Whakamahi i ngā Konganuku Utu Nui pērā i te Koura me te Hiriwa
He tukanga nui te whakamahine i ngā konganuku utu nui pērā i te koura (Au) me te hiriwa (Ag) hei whakanui ake i te parakore o ngā konganuku mai i ngā konganuku, ngā mea kua whakaemihia, ngā rauemi hangarua rānei (hei tauira, ngā whakapaipai kua whakamahia, ngā para hiko, me ngā para ahumahi). Nā te nui o te uara ōhanga me te whakamahinga whānui i roto i ngā whakapaipai, ngā hikohiko, te rongoā, me te haumi, he maha ngā wā ka hiahiatia kia tino teitei ngā paerewa parakore o te koura me te hiriwa, hei tauira, 99,9% (3N) tae atu ki te 99,99% (4N). Hei whakatutuki i ēnei taumata, ka whakamahia ngā tikanga whakamahine maha, i tīpakohia i runga i te momo rauemi mata, te nui o te paru, te tauine whakaputa, ngā utu, me ngā whakaaro haumaru me te taiao.
1. Ngā Wāhanga Whānui o te Whakamaeneene: Mai i te Mea Kukū ki te Mea Parakore
I te nuinga o te wā, he maha ngā wāhanga o te whakangawari i te koura me te hiriwa. Ko te tuatahi ko te whakarite rauemi: te kuru, te huri, te wehenga ā-tinana (hei tauira, te kaha ā-papa, te whakamātao rānei), me te whakamaroke. Kātahi ka tukatukahia te rauemi mā te tango (te horoi, te whakarewa rānei) hei tango i te konganuku utu nui mai i te toka, i te hanganga koranu rānei. Muri iho, ka mahia te whakangawari hei tango i ngā paru e toe ana kia tae rā anō ki te taumata e hiahiatia ana.
Ka taea te whakahaere i te whakangao koura me te hiriwa mā te whakamahi i te pyrometallurgy (te wera/te whakarewa), te hydrometallurgy (te waihanga matū), te electrometallurgy rānei (te electrolysis). I roto i te mahi, he maha ngā tikanga ka whakamahia e te umanga hei whakatutuki i te whai huatanga me ngā hua kounga teitei.
2. Te Whakamahinga mā te Pyrometallurgy (Te Whakarewa me te Wehewehe)
a) Te Wehenga o te Whakarewa me te Para (Te Whakarewa)
I roto i ētahi konganuku, i ētahi matū whakapūmau rānei, ka whakapūmauhia ngā konganuku utu nui mā te whakarewa i aua konganuku ki te wai. Ko te whāinga he hanga i tētahi konganuku wai, i tētahi konganuku matte rānei e kawe ana i te koura/hiriwa, ā, ka whakawhitia ngā paru ki te para. Ko tēnei wāhanga te "whakapūmautanga tuatahi," engari i te nuinga o te wā kāore e puta he konganuku tino parakore.
b) Te whakakākahu hei wehe i te hiriwa/koura mai i te mata
Ko tētahi tikanga matarohia e whakamahia whānuitia ana ko te cupellation, arā, ko te whakamahana i tētahi koranu mata (Pb) me tētahi konganuku utu nui i raro i ngā āhuatanga waikura. Ka waikura te mata ki te PbO2 (litharge) ka mimiti ki roto i te rauemi porous (cupel), ko te koura me te hiriwa utu nui ka mahue iho. He whai hua tēnei tikanga mō ētahi tauira, ā, e whakamahia ana hoki i roto i te whakamātautau, engari ko tōna whakamahinga i runga i te tauine ahumahi hou he iti noa iho i ngā take tukunga me te hiahia mō te whakahaere tukanga.
c) Te Wehewehe: Te Wehe i te Koura me te Hiriwa
Mena kei roto te koura me te hiriwa hei koranu (hei tauira, i roto i ngā koranu hikohiko, i ngā koranu whakapaipai rānei), me wehe te koura hei wehewehe i a rāua. Ko te tikanga, ko te wehewehe ko te whakarewa i te hiriwa ki tētahi waikawa motuhake, kia kore ai e wairewa te koura. Mai i reira, ka taea te whakahoki anō i te hiriwa, ā, ka tukatukahia anō te koura kia parakore ai.
He pakari te pyrometallurgy mō te whakahaere i ngā rahinga nui me ngā rauemi uaua, engari ko te whakapaunga pūngao me te whakahaere tukunga ngā āwangawanga matua.
3. Te Whakamahinga mā te Hydrometallurgy (Te Whakarewatanga Kōwhiringa me te Ua)
Ka whakamahia e te hydrometallurgy ngā tauhohenga matū i roto i te wairewa hei whakarewa i te koura/hiriwa, kātahi ka wehea mai i ngā poke. Ko ōna painga ko te tino whiriwhiri me tōna whakamahinga ki te whānuitanga o ngā rauemi mata, tae atu ki ngā rauemi hangarua.
a) Te Cyanidation mō te Koura (Cyanidation)
Ko tētahi o ngā tikanga tino rongonui mō te tango koura ko te cyanidation, arā, ka whakarewaina te koura ki roto i te wairewa cyanide i te aroaro o te hāora, ka hanga he matū wairewa. Kia tae te koura ki roto i te wairewa, ka mahia te whakaora mā roto i:
– Te mimiti waro whakahohe (CIP/CIL): ka herea te koura ki te waro, kātahi ka tukuna (whakapūtātanga) ka whakapūtā.
– Te whakapūtanga konutea (Merrill–Crowe): ka whakapūtangatia te koura mai i te wairewa mā te āwhina o te konutea, he mea e tika ana mō ngā wairewa mārama he nui te koura kei roto.
I muri i te whakaoranga o te koura, me whakapai tonu te koura (hei tauira, mā te whakarewa kia rite ki ngā pae koura, kātahi ka whakapai ake mā te hiko-matū).
He kōrero nui: he tino whakahaeretia te whakamahinga o te cyanide nā tōna paitini, nō reira ka whakamahia e ngā whare hou ngā pūnaha kati, te tango paitini para, me te aroturukitanga pakari i te taiao.
b) Te Whakarewatanga Hiriwa: Nitrate me te Thiosulfate
He māmā noa te hanga tote/pūhui wairewa o te hiriwa. I ētahi tukanga, ka taea te waimeha te hiriwa hei nitrate hiriwa i roto i tētahi pāpāho motuhake, kātahi ka whakahokia mai mā te whakapūnga (hei tauira, hei AgCl) mā te whakaheke rānei ki te konganuku. Ko ētahi atu huarahi ko ngā pūnaha uaua pēnei i te thiosulfate i raro i ngā āhuatanga whakahaere. Ko te whiriwhiri i te matū ka pāngia e te momo rauemi me ngā poke o reira.
c) Te Whakapūtanga Ua me te Whakamaematanga Wairewa Whiriwhiri
I muri i te rewa o te konganuku, he maha ngā poke kei roto i te otinga (te parahi, te rino, te konutea, te nikara). Ko ngā tikanga e whakamahia ana ko:
– te whakatikatika i te pH hei whakapiki i ngā hauwaiwai poke.
– Te tāpiri i ngā matū whakapakeke hei hanga i ētahi matū kore e rewa.
– Te whakawhiti katote hei hopu kōwhiri i ngā matatini whakarewa.
– Te tango whakarewa i roto i ētahi kaupapa ahumahi.
Ko te angitu o te hydrometallurgy kei roto i te whakahaere i te matū otinga: te pH, te pūmanawa redox, te pāmahana, me te kukū o te matū matū.
4. Te Whakamahi Hiko: Ngā Paerewa Teitei mō te Parakore
Hei whakatutuki i te parakore tino teitei, ka whakamahia whānuitia e te umanga te whakamahine hikohiko. Ko te kaupapa matua: ka whakamahia ngā konganuku poke hei anode, ka rewa i te wā e hikohiko ana. Kātahi ka tau ngā konganuku parakore ki runga i te cathode, i te mea ka noho tonu ētahi poke, ka mimiti rānei ki roto i te paru.
a) Te Tukanga Wohlwill mō te Koura
He tukanga whakapūmau hiko koura a Wohlwill e taea ai te whakaputa koura tino parakore (tae atu ki te 99,99%). Ka whakamahia te koura dore (koura mata) hei anode, ā, ka tau te koura parakore ki runga i te cathode. Ko ngā poke pēnei i te hiriwa ka hanga he tau kore e rewa, ka kohia hei paru anode, kātahi ka tukatukahia hei whakaora i ētahi atu konganuku utu nui (tae atu ki te hiriwa me ngā konganuku rōpū platinum).
Ko te painga o tēnei tukanga ko te kounga hua tino teitei, engari me whai mana pai te whakahaere i ngā irahiko me ngā hanganga.
b) Te Tukanga Moebius mō te Hiriwa
Mō te hiriwa, ko tētahi tikanga whakapūmau hiko rongonui ko te tukanga Moebius. Ka rewa te hiriwa anode, ka puta hei tioata hiriwa parakore i runga i te cathode. Kāore e rewa ngā poke pēnei i te koura, ā, ka kohia hei paru anode, ka taea te tukatuka motuhake. He pai tēnei tukanga, ā, he mea noa te whakamahi i roto i ngā whare whakapūmau hiriwa.
He tino pai te whakamahine hiko ki te whakaputa i te "kōeke puru" me ngā "konganuku pai" rānei, engari me whai pūtake hiko, me whakahaere otinga, me te whakahaere i te paru anode kei roto ngā konganuku utu nui me ngā poke kino.
5. Te Whakamahinga mai i ngā Rauemi Hangarua (Keritanga Tāone)
I te pikinga ake o ngā para hiko, kei te piki haere te hiranga o te purenga o te koura me te hiriwa mai i ngā "maina o te tāone". Kei roto i ngā papa porowhita (PCB), ngā hononga, me ētahi wāhanga he iti noa te koura/hiriwa engari he nui te uara. Ko te tikanga o te tukanga ko:
1. Te maimoatanga ā-mīhini: te whakarōpū, te kuru, te wehenga aukume/au hurihuri.
2. Te tango i te konganuku taketake i te tuatahi (hei tauira, te parahi), kātahi ka tangohia te koura/hiriwa.
3. Te whakamahine anō: te whakatauira i te matū, te whakamahine hiko rānei.
Ko ngā wero matua o te hangarua ko te uaua o ngā rauemi (kirihou, kapia, ārai mura brominated) me te kaha o te whakaputa para kino. Nō reira, ko ngā tukanga hangarua hou e aro nui ana ki ngā pūnaha kati, te tātari, me te tukatuka para tino pakari.
6. Mana Kounga: Whakamātautau Ihirangi me te Tiwhikete
Ko ngā hua koura me te hiriwa parakore ka manatokohia mā roto i ngā tikanga tātari pēnei i:
– Whakamātautau ahi (hei whakatau tika i te nui o te koura/hiriwa).
– XRF (whakapūtanga hihi-X) mō te tātaritanga hanganga tere.
– ICP-OES/ICP-MS mō te tino tika i ngā taumata poke iti.
Hei tāpiri, ko te koura parakore mō te mākete haumitanga e hiahiatia ana he tiwhikete, he tānga wheketere (mint/refinery), he tau rangatū, me ētahi paerewa parakore.
7. Ngā Āhuatanga Haumaru me te Taiao
Ka tūpono te ahumahi ki ngā matū waikura me ngā matū paitini i te whakamahine i ngā konganuku utu nui, tae atu ki ngā tukunga pea. Ko ngā mahi pai ko:
– Pūnaha hauhautanga me te mīhini horoi hau.
– Te maimoatanga wai para me te tango paitini mai i ngā matū.
– Te whakamahi i ngā taputapu tiaki whaiaro me ngā tikanga whawhati tata.
– Ngā arotake taiao me te tutuki i ngā ture.
Ka akiakihia hoki e ngā huarahi hou ngā tauhohenga e pai ake ana ki te taiao, te whai huatanga o te pūngao, me te whakaora matū mai i te tukanga.
Whakamutunga
Ko ngā tikanga whakamahine koura me te hiriwa he whakakotahitanga o te pyrometallurgy, te hydrometallurgy, me te electrometallurgy, ko te whakamahine hiko te mea nui ki te whakatutuki i te parakore teitei. Ko te whiriwhiri i te tikanga e whakawhirinaki ana ki te rauemi pūtake—ahakoa he konganuku, he kukū, he para hangarua rānei—me ngā whāinga parakore me te whai hua o te utu. I tēnei wā ahumahi hou, ehara i te mea ko ngā konganuku utu nui kounga teitei anake te mea e hiahiatia ana mō te whakamahine, engari ko te haumaru, te tutuki i ngā ture, me te kawenga taiao. I roto i ngā whanaketanga hangarau, kei te neke tonu ngā tukanga whakamahine ki ngā pūnaha whiriwhiri, whai hua i te pūngao, me te pumau, me te kore e whakararu i te kounga o te koura me te hiriwa e whakaputaina ana.
