Ngā Tikanga me ngā Tikanga mō te Tukatuka Koura mai i te Kohatu
Ko te tukatuka koura mai i te konganuku he raupapa o ngā tukanga hangarau hei wehe me te pure i te koura mai i ngā rauemi toka kei roto ngā kohuke utu nui. Nā te mea kāore te koura e kitea i te nuinga o te wā i roto i te āhua "parakore" e wātea ana i roto i te taiao, me whai tikanga tika—mai i te whakarite konganuku, te wehenga ā-tinana, te tango wai, me te whakamahine whakamutunga. E matapakihia ana e tēnei tuhinga ngā tikanga me ngā tikanga noa mō te tukatuka koura mai i te konganuku, me ōna mātāpono mahi, ngā painga me ngā ngoikoretanga, me ngā āhuatanga nui o te haumaru me te taiao.
1. Ngā Āhuatanga o te Koura me te Hiranga o te Whakamātautau Tuatahi
I mua i te whiriwhiri i tētahi tikanga tukatuka, he mea nui te mārama ki ngā āhuatanga o te kōura. Ka taea e te kōura te:
– Ngā konganuku waikura (he māmā ake te tukatuka).
– Ngā konganuku whanariki (he maha ngā wā ka "aukati" te koura nā te mea ka mau te koura i roto i ngā konganuku whanariki pērā i te pyrite/arsenopyrite).
– Te konganuku waro, te tango rānei i te koura i mua i te wā (ka mimitihia e te waro tūturu te koura, ā, ka whakaitihia te whakaora).
– Te whenua whakatō/te whenua whakatō (ngā kōura kore utu i roto i te onepū/kirikiri awa).
I roto i ngā mahi ahumahi, ka whakahaerehia ngā whakamātautau whakarewa pēnei i te tātari i te ihirangi koura (whakamātautau ahi), te whakamātautau kohuke (mākairotiro/XRD), me ngā whakamātautau tango wai i te taiwhanga hei whakatau i te whakaoranga me te whakatau i te huarahi tukanga tino whai hua.
2. Te Whakarite i te Kohatu: Te Kuru me te Huri
Ko te wāhanga tuatahi o te tukatuka he whakaiti i te rahi o te konganuku kia watea ai ngā kohuke koura i ngā toka poke.
1) Te kuru
He nui te rahi o te konganuku mai i te maina, kātahi ka kuruhia mā te whakamahi i te mīhini kuru kauae, i te mīhini kuru kōne rānei, kia kotahi henimita te rahi.
2) Te huri/mira
Whai muri i tēnā, ka hurihia te konganuku mā te whakamahi i te mira pōro, i te mira SAG rānei kia iti ake te rahi (hei tauira, 80% ka hipa i te 75–150 maikorona), i runga anō i ngā whakaritenga tukunga.
Ehara i te mea ko te whakamahine noa i te rauemi te whāinga, engari kia tutuki te rahi tino pai. Mēnā he matotoru rawa te rauemi, ka uaua te tango i te koura, ā, ki te mea he maeneene rawa, ka nui ake te whakamahinga o te matū, ā, ka uaua hoki te wehenga totoka-wai.
3. Te Kukū o te Āhua-ā-Toi: Te Whakamahi i ngā Rerekētanga o te Āhua-ā-Toi Motuhake
Mena he koura kore-matotoru kei roto i te konganuku, he tino whai hua te tikanga ā-papatipu nā te mea he teitei te taumaha motuhake o te koura.
Ngā taputapu noa:
– Pouaka parai (he mea noa i runga i te tauine iti/paraihe).
– Pūwhakakotahi porowhita.
– Tēpu rūrū.
– Pūwhakakotahi Knelson, pūwhakakotahi Falcon rānei (pūwhakakotahi tohanga).
Ko ngā painga o te tikanga tātai taumaha ko tōna māmā noa iho, he iti ngā utu whakahaere, ā, kāore e whakawhirinaki ki ngā matū. Ko ngā ngoikoretanga ko tōna koretake mō te koura tino pai, mō te koura rānei e herea ana ki ngā kohuke whanariki.
4. Te Whakarewatanga: Te Whakakotahi i ngā Kohuke e mau ana i te Koura
Mō ngā konganuku whanariki, he maha ngā wā ka honoa te koura ki te pyrite, te chalcopyrite, te arsenopyrite rānei. I ēnei wā, ka taea te whakamahi i te whakapūngā hei whakaputa i ngā kukū whanariki kounga teitei, ka whakaiti i te rahinga o ngā rauemi e hiahia ana kia tukatukahia atu.
Te mātāpono o te rere:
– Ka hangaia ngā matūriki kohuke kia kore ai e wai te wai mā roto i ngā kaikohi (hei tauira, te xanthate).
– Ka pupuhihia te hau kia piri ngā kohuke wai-ātete ki ngā mirumiru, kia mānu ai hei pahuka (he kukū).
– Ka toe tonu ētahi atu kohuke i roto i te penupenu hei para.
Ko ngā hua whakapūmau (ngā mea kukū) ka tukatukahia anō mā roto i ngā tukanga tātā, waikura rānei (ina koa mō ngā konganuku ātete-waikura).
5. Te Whakarewa: Te Whakarewa Matū i te Koura
Ko te horoi te ngākau o ngā mira koura o ēnei rā. Ka whakarewaina te koura kua wetekina hei matū wairewa, kātahi ka whakahokia mai.
a) Te whakapūmautanga
Ko te tikanga ahumahi e whakamahia whānuitia ana ko te tango i te cyanide, nā te mea he whai hua, he whiriwhiri hoki mō ngā konganuku maha. Ka hangaia e te koura he matū wairewa i roto i ngā wairewa cyanide i raro i ngā āhuatanga pH kawakore me te aroaro o te hāora.
E rua ngā whirihoranga noa:
– CIL (Waro-i-te-Tae): ka whakanohoia te waro whakahohe ki roto i te tāke tāe hei mimiti i te koura kua rewa.
– CIP (Waro-i-te-Pulup): ka oti te tango waro i te tuatahi, kātahi ka oti te whakawaro i te wāhanga e whai ake nei.
Ngā Painga: he nui te whakaora i runga i ngā konganuku e tika ana, ā, kua whakamātauhia i runga i te tauine nui.
Wero: me tino whakahaere i ngā tawhā tukanga me te whakahaere para haumaru.
b) Te Whakarewa Puranga
Mō te konganuku iti te kounga me te ngāwari ki te tango, ka whakamahia te tango puranga:
– Ka kuruhia te konganuku, ka whakaemihia i ētahi wā, kātahi ka whakatakotoria ki runga i tētahi papa hiri.
– Ka ringihia (ka whakamakukuhia) te wai rētihi mai i runga.
– Ka kohia te wai hapū i raro, kātahi ka tukatukahia kia riro mai ai te koura.
He iti ake ngā utu whakapaipai o tēnei tikanga i ngā tipu CIL/CIP, engari he puhoi ake te nuinga o te wā, ā, he iti ake te whakaora.
c) Ngā Huarahi Whakakapi Kore-Cyanide (Kei te Whaihua)
He iti noa iho ētahi huarahi kē atu kua rangahaua/kua whakatinanahia:
– Te tangohanga o te thiosulfate (te kaha ki te tango i te konganuku i mua i te tīmatanga o te mahi keri).
– Te tātā i te hauhā (te hauota/te pūromāota i raro i ētahi tikanga).
Heoi, i te nuinga o te wā, he uaua ake te whakahaere tukanga mō tōna whakamahinga, ā, kāore i te rite te noa ki te cyanidation mō te maha o ngā maina.
6. Te Tukatuka Kohatu Ātete: Te Waikura i mua i te Whakarewa
Ko ngā konganuku ātete-wai he konganuku e "maukati" ana te koura ki roto i ngā kohuke whanariki, e āraihia ana rānei e tētahi matihiko motuhake, ā, ka kore e whai hua te cyanide me te kore e tukatukahia i mua. Ko ngā tikanga tukatuka i mua ko:
1) Te tunu
Ka waikuratia ngā whanariki i ngā pāmahana tiketike, ka nui ake te kitea o te koura. Me whakahaere te tukunga (hei tauira, SO₂/As).
2) Te Whakahāora Pēhanga (POX)
Te waikura i roto i te autoclave pēhanga me te hāora. Tērā pea he nui te whakaora, engari he nui ngā utu whakapaipai.
3) Te Whakahāora-koiora (BIOX)
Te whakamahi i ngā huakita hei whakawairakau i ngā whanariki i raro i ngā āhuatanga whakahaere. He "mātao ake" i te tunu, engari me roa te wā tukatuka me te whakahaere i te bioreactor.
I muri i te whakahāora-mua, ka horoia te konganuku/te konganuku kukū (te nuinga o te wā ki te cyanide) hei whakarewa i te koura.
7. Te Whakaora Koura mai i te Wairewa: Waro Whakahohe, Resin, me te Ua
Kia rewa te koura, ko te mahi e whai ake nei ko te tango mai i te wairewa.
– Te mimiti waro whakahohe (CIP/CIL): ka mimiti te waro i te koura. Kātahi ka tangohia te waro mā te whakamahi i tētahi otinga motuhake hei tuku i te koura.
– Te Kapia-i-roto-i-te-Pulp (RIP): ka whakakapia te waro e te kapia whakawhiti katote i raro i ētahi āhuatanga, i ētahi wā ka ātete ake ki te poke.
– Te whakapūtanga konutea (Merrill–Crowe): ka whakamāramatia te wairewa momona, ka tangohia te hāora, kātahi ka whakapūtangatia te koura mā te whakamahi i te paura konutea. He pai tēnei tikanga mō ngā wairewa ma.
Ko te mutunga iho he paru/he konganuku kukū, ka rewahia hei doré (he koranu koura-hiriwa) i mua i te whakapainga anō.
8. Te Whakarewa me te Whakamahinga
Ka whakamaroketia te hua i whakahokia mai (hei tauira, te matū elution, te Merrill-Crowe rānei) kātahi ka rewa mā te whakamahi i te flux hei whakaputa i te doré bar. Kātahi ka purea te doré i roto i te whare hanga para mā te:
– Ngā tukanga hikohiko (hei tauira, Wohlwill mō te koura parakore teitei).
– Te tukanga Miller (te whakamahi i te chlorine hei wehe i ētahi poke).
Mā te whakamahine ka puta te koura kounga teitei (hei tauira, 99,99%) e ai ki ngā paerewa tauhokohoko.
9. Te Whakahaere i ngā Parapara, te Wai Tukanga, me ngā Āhuatanga Taiao
Ko te tukatuka koura ka puta tonu mai ngā paru (ngā toenga totoka) me te wai tukatuka, me whakahaere haumaru ēnei. Ko ngā mahi noa ko:
– Te whakamātotoru me te penapena i ngā para ki roto i te TSF (whare penapena para) me te hoahoa hangarau whenua.
– Hangarua anō te wai tukatuka hei whakaiti i te whakapaunga wai.
– Te tango paitini i ngā toenga matū (hei tauira, te whakaiti i ngā toenga cyanide mā roto i ētahi tukanga waikura mēnā e tika ana).
– Te aro turuki i te kounga o te wai, te pumau o ngā tāpae para, me ngā mahere kati maina.
He mea nui anō hoki ngā āhuatanga Hauora me te Haumaru Mahi (K3): me whakauru te whakamahinga o ngā matū hohe, te whakahaere puehu, te ārai i te pānga ki ngā rauemi morearea, me ngā tikanga ohorere ki roto i te pūnaha whakahaere.
10. Whakamutunga
Ko ngā tikanga me ngā tikanga mō te tukatuka koura mai i te konganuku e whakawhirinaki ana ki te momo konganuku, te rahi o te tukunga, me ngā āhuatanga o te kohuke. Ko ngā huarahi tukatuka noa ko te kuru me te huri, te kukū me te/ranei te whakatārewatanga o te kaha ā-papa, te tango (he maha ngā wā ko te cyanidation i roto i te CIL/CIP, te puranga rānei), te whakaora koura mai i te otinga, kātahi ka whakarewa me te whakamahine. Mō ngā konganuku ātete-waikura, me mahi ngā mahi i mua i te waikura pēnei i te tunu, te POX, te waikura-koiora rānei kia pai ai te tango i te koura. I runga ake i ngā mea katoa, ko te angitu o te tukatuka koura hou ka whakatauhia hoki e te whakatinanatanga o ngā mana whakahaere tukanga pakari, te whakahaere i ngā paru me te wai, me te whakapau kaha ki te haumaru mahi me te tiaki taiao.
Ki te hiahia koe, ka taea e au te whakarerekē i tēnei tuhinga ki tētahi horopaki tauine ahumahi (me ngā pepa rere me ngā tawhā whānui), ki tētahi tauine iti/waenga rānei (e aro nui ana ki te kukū o te kaha ā-papa me ngā mahi whakahaere taketake) kia rite ki ō hiahia.
