Tailings tafkunan wasu manyan gine-ginen injiniya ne a Duniya, duk da haka manufarsu da gininsu sun kasance abin ban mamaki ga mutane da yawa a wajen masana'antar hakar ma'adinai. Waɗannan ba tafkuna masu sauƙi ba ne; wurare ne masu rikitarwa masu mahimmanci don ayyukan hakar ma'adinai na zamani.

Wannan jagorar tana ba da cikakken bayyani na yadda ake gina tafkunan wutsiya, daga zaɓin wurin farko zuwa rufewa na dogon lokaci. Za mu bincika matakan injiniya masu mahimmanci, hanyoyin gini, da kayan da aka yi amfani da su-musamman geosynthetics-don gina ginin da ke da ingantaccen aiki da tsaro.

Menene Tafkin Tailings Da Manufarsa

Da farko, bari mu fayyace abin da muke ginawa. Tafkin wutsiya, ko Wurin ajiya na wutsiya (TSF), is a large engineered dam and containment structure used to store the waste byproducts of mining operations. "Tailings" su ne dutsen da aka nitse da kuma sarrafa ruwa da ya rage bayan an fitar da ma'adanai masu mahimmanci. Wannan slurry, cakuda ruwa da ƙananan barbashi, ana tura su zuwa TSF don ajiya na dindindin.

Babban manufar tafkin wutsiya abu biyu ne:

1. Abun ciki: Don adana ɗimbin ɗimbin kayan sharar gida lafiya har abada.
2. Gudanar da Ruwa: Don ƙyale ƙaƙƙarfan ƙaƙƙarfan ɓangarorin su daidaita, don haka ana iya fayyace tsarin ruwa da sake yin fa'ida a cikin aikin hakar ma'adinai, rage buƙatar ruwa mai daɗi.

Saboda wutsiya na iya ƙunsar ragowar sinadarai da karafa, hana duk wani kutsawa cikin muhallin da ke kewaye shine babban aikin injiniya da fifikon muhalli.

Zaɓin Yanar Gizo da Ƙirƙirar Injiniya na Farko

Nasarar da amincin tafkin wutsiya suna farawa tun kafin a motsa kowane datti. Zaɓin wurin da ya dace shine mataki na farko mai mahimmanci, wanda ya haɗa da ƙima mai yawa. Injiniyoyi suna tantancewa:

• Yanayin Geological da Geotechnical: Kwanciyar ƙasa da dutsen da ke ƙasa shine mafi mahimmanci. Shafukan da ke da tushe mai rauni ko babban haɗarin zaizayar ƙasa ana kaucewa.
• Hoton hoto: Ana fi son kwaruruka na yanayi ko kwanukan ruwa saboda za su iya rage adadin ginin dam da ake buƙata.
• La'akarin Seismic: A cikin yankunan da ke fama da girgizar ƙasa, dole ne wurin da zayyana madatsun ruwa su iya jure girgizar ƙasa. Wannan al'amari yana tasiri sosai akan nau'in dam da za'a iya ginawa.
• Kimiyyar Ruwa: Fahimtar magudanar ruwa da ruwa na ƙasa yana da mahimmanci don hana ginin daga mamayar ruwan sama da kuma kare albarkatun ruwa na gida.
• Kusa da Ayyukan Ma'adinai: Dole ne wurin ya kasance kusa da ma'adinan don sa yin famfo wutsiya mai yuwuwar tattalin arziki.

Da zarar an zaɓi wani wuri, an ƙirƙiri cikakken ƙirar injiniyanci, wanda ke bayyana girman ginin wurin, nau'in dam ɗin da za a yi, da na'urorin da ake buƙata da na'urorin da ake buƙata.

Shirye-shiryen Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarfafawa

Tare da zane a wurin, shiri na site fara. Wannan yayi kama da shirya harsashin kowane babban tsarin farar hula. Tsarin ya ƙunshi:

• Sharewa da Gwozawa: Dukkan sawun kayan aikin an share shi daga duk ciyayi, ƙasan sama, da manyan duwatsu.
• Hakowa da Matsayi: An tono ƙasa kuma an ƙididdige shi zuwa ƙirar ƙirar ƙira.
• Ƙarfafawa: Ƙasar ƙasa an haɗa ta zuwa ƙayyadadden ƙima don ƙirƙirar ƙaƙƙarfan, tsayayye, da tushe iri ɗaya don tsarin layin da dam.
• Maganin Ƙasa mara ƙarfi: Idan an gano wasu aljihu na ƙasa mai rauni, ana cire su kuma a maye gurbinsu da injin cikawa.

Wannan matakin yana da mahimmanci saboda duk wani sulhu na tushe na gaba zai iya sanya damuwa a kan tsarin layin da kuma lalata mutuncinsa.

Gina Rumbuna da Dams

Dam ɗin dam ɗin ya kasance mafi shaharar yanayin tafki na wutsiya. Hanyar ginin da aka zaɓa ta dogara sosai akan haɗarin girgizar ƙasa, halayen wutsiya, da kasafin kuɗi. Akwai hanyoyi na farko guda uku don haɓaka dam ɗin a tsawon rayuwarsa:

Hanyar Haɓakawa

This is the oldest and least expensive method. After a small "starter dam" An gina shi, an fitar da slurry na wutsiya daga ƙugiya. Ƙaƙƙarfan barbashi sun zauna kusa da dam, suna kafa rairayin bakin teku, wanda ya zama tushe don mataki na gaba na haɓaka dam. Ƙaƙƙarfan dam ɗin yana motsawa a hankali sama, sama da wutsiya da aka kafa. Duk da yake yana da tsada, wannan hanyar tana da saurin kamuwa da gazawa daga lalatawar girgizar ƙasa kuma yanzu an hana ta ko kuma an iyakance ta sosai a ƙasashe da yawa.

Hanyar ƙasa

Wannan ita ce hanya mafi aminci amma mafi tsada. An gina dam ɗin kuma an ɗaga shi ta hanyar sanya sabbin abubuwa a gefen ƙasa, don haka tsarin ba a kafa shi akan wutsiya da kansu ba. Yawanci ana gina madatsar ruwa tare da ingantacciyar inzara, madaidaicin magudanar ruwa, masu tacewa, da wuraren magudanar ruwa, kamar madatsar ruwa ta al'ada. Wannan hanyar tana buƙatar ɗimbin girma na kayan gini da kuma ƙaƙƙarfan sawun ƙasa.

Hanyar Tsakiya

Wannan hanyar ita ce haɗakar hanyoyin sama da ƙasa. Ƙwararren madatsar ruwa yana tasowa a tsaye, tare da layin tsakiya ya rage a matsayi ɗaya. Sau da yawa yana amfani da guguwa don raba wutsiyoyi zuwa cikin yashi mai ƙaƙƙarfan don gina madatsar ruwa da ƙananan barbashi waɗanda aka ajiye a cikin tafki. Yana ba da mafi kyawun kwanciyar hankali fiye da hanyar sama a farashi mai arha fiye da hanyar ƙasa.

Tsarin Tsarin Liner don Tafkunan Tailings

Don hana gurɓataccen ruwa shiga cikin ƙasa, ana gina tafkunan wutsiya na zamani tare da ingantattun na'urori masu launi iri-iri. Manufar ita ce a ƙirƙiri shingen haɗe-haɗe tare da ƙarancin ƙarancin ƙarfi.

Tsarin layi na yau da kullun, daga ƙasa zuwa sama, na iya haɗawa da:

• Ƙwararren Clay Liner (CCL): An sanya wani kauri mai kauri na yumbu mai ƙarancin ƙarfi a kan shirye-shiryen da aka shirya kuma an haɗa shi don cimma shinge na hydraulic.
• Geosynthetic Clay Liner (GCL): A yawancin ƙirar zamani, ana amfani da GCL a maimakon ko ƙari ga CCL. GCL samfuri ne na masana'anta wanda ya ƙunshi sirin yumɓun yumɓu na bentonite sandwiched tsakanin geotextiles biyu. Ya fi sauƙi don shigarwa kuma yana ba da ƙarin aiki mai daidaituwa fiye da CCL mai kauri.
• Geomembrane: Wannan shi ne shinge na farko. A lokacin farin ciki (yawanci 1.5 mm zuwa 2.5 mm) High-Density Polyethylene (HDPE) geomembrane an shigar a kan laka liner. An zaɓi HDPE don kyakkyawan juriya na sinadarai, dorewa, da ƙarancin ƙarfi.

This combination of a geomembrane and a GCL/CCL creates a "composite liner" wanda ya fi tasiri wajen hana zubewa fiye da ko wane bangare da aka yi amfani da shi kadai.

Shigar da Magudanar ruwa da Tsarukan tattarawa

Sama da layin farko, an shigar da tsarin magudanar ruwa da ɗigogi. Manufarsa ita ce tattara duk wani leach ɗin da ke ratsa wutsiya da sauri ganowa da kama duk wani ɗigogi mai yuwuwa daga layin farko.

Wannan tsarin yawanci ya ƙunshi:

• Layin Ruwan Ruwa: Yashi mai tsafta ko tsakuwa, ko fiye da haka, a magudanar ruwa geocomposite. Geocomposite yana haɗa babban magudanar ruwa na filastik (geonet) tare da matatar geotextile da ke ɗaure da ita. Geocomposites galibi ana fifita su saboda sun fi sauƙi, mafi tsada-tasiri don shigarwa, da kuma samar da injiniyoyi, aikin magudanar ruwa mai tsinkaya.
• Bututun Tattara Rarraba: Ana shigar da hanyar sadarwa na bututu mai ratsa jiki a cikin magudanar ruwa don tattara ruwan da kuma kai shi zuwa wani tudu, daga inda za a iya fitar da shi.

Wannan tsarin gaba ɗaya yana zaune a tsakanin layin layi da wutsiya, yana samar da tsarin tattarawa da farfadowa (LCRS).

Tailings Deposition da Tsarin Gudanar da Ruwa

Da zarar an gina tsarin ɗaukar hoto, lokacin aiki zai fara.

• Adadin Tailings: The tailings slurry is pumped from the processing plant and discharged into the pond, usually from spigots placed along the dam's perimeter. The goal is to deposit the coarse particles along the dam to form a stable "beach" yayin da finer barbashi zauna a tsakiyar kandami.
• Gudanar da Ruwa: Yayin da daskararrun ke daidaitawa, ruwa mai tsabta yana samuwa a saman kandami. Ana tattara wannan ruwa ta hanyar a decant tsarin- sau da yawa jirgin ruwan famfo mai iyo ko hasumiyar kankare a tsaye - kuma a mayar da shi zuwa masana'antar sarrafa don sake amfani da shi. Hakanan ana gina maɓuɓɓugan gaggawa don sakin ruwa mai yawa a cikin aminci yayin bala'in guguwa.

Matakan Kariya na gangara da Yazara

Dole ne a kiyaye gangar jikin dam ɗin na waje daga zaizayar ƙasa da iska da ruwan sama ke haifarwa. Wannan yana da mahimmanci don kiyaye amincin tsarin dam ɗin na dogon lokaci.

Ana amfani da kayan aikin geosynthetic iri-iri don wannan dalili:

• Geotextiles: Za a iya sanya Layer na geotextile mara saƙa ko saƙa a saman gangara don hana asarar ƙasa kafin a kafa ciyayi.
• Geocells: Za a iya shigar da tsarin geocell mai girma uku a kan gangara, cike da ƙasa, da ciyayi. Tsarin saƙar zuma na geocell yana taƙaita ƙasa, yana hana ta wankewa ko da a kan tudu masu gangare.
• Bargon Kula da Yazara: Ana amfani da barguna masu lalacewa ko dindindin da aka yi da zaruruwan yanayi ko kayan roba don daidaita saman da haɓaka ci gaban ciyayi.
• riprap: A cikin wuraren da ruwa ya tattara, manyan duwatsu masu kusurwa (riprap) ana sanya su a kan wani geotextile don yin sulke ga gangaren da za a yi.

Kulawa, Kayan aiki, da Kula da Tsaro

A tailings pond is not a "build and forget" tsari. Wuri ne mai ƙarfi wanda ke buƙatar ci gaba da sa ido a duk rayuwarsa. An shigar da hanyar sadarwa na kayan aiki don bin diddigin ayyukanta da kuma ba da gargaɗin farko game da duk wata matsala mai yuwuwa:

• Piezometers: Ana shigar da waɗannan kayan aikin a cikin dam ɗin don auna matsa lamba na ruwa (matsi na pore), wanda shine maɓalli na alamar kwanciyar hankali.
• Inlinometers da Monuments na Bincike: Ana amfani da waɗannan don ganowa da auna duk wani motsi a kwance ko a tsaye na dam.
• Duban Tarin Shafi: Ana auna ƙarar ruwan da aka tattara daga tsarin magudanar ruwa a hankali don gano duk wani karuwa wanda zai iya nuna yabo.

Binciken gani na yau da kullun kuma muhimmin sashi ne na ka'idar aminci.

Rufewa, Gyarawa, da Gudanar da Tsawon Lokaci

Lokacin da ma'adinan ya daina aiki, tafkin wutsiya dole ne a rufe shi har abada kuma a cikin aminci. Makasudin rufewa shine a ƙirƙiri wani tsari na sinadari da kwanciyar hankali na jiki wanda ke buƙatar ƙaramin kulawa na dogon lokaci.

Tsarin rufewa yawanci ya ƙunshi:

1. Dewatering: Cire ruwa mai yawa kamar yadda zai yiwu daga wurin.
2. Ƙarfafawa: Ba da izinin wutsiya don daidaitawa da ƙarfafawa.
3. Tsarin Rufin Ƙarshe: Capping duka kayan aiki tare da tsarin rufewa mai nau'i-nau'i masu yawa, kama da layin tushe. An tsara wannan murfin don hana ruwan sama shiga cikin wutsiya da kuma tallafawa ciyayi mai dorewa.
4. Gudanar da Ruwan Sama: Gina tashoshi na dindindin da magudanar ruwa don amintar da ruwan sama a kashe da kewayen wurin.
5. Farfadowa: Ƙirƙirar murfin ciyayi mai dogaro da kai don sarrafa zaizayar ƙasa da dawo da aikin muhallin wurin.

An ci gaba da sa ido kan kwanciyar hankali da ingancin ruwa bayan rufe madatsar ta tsawon shekaru da dama.

Takaitawa

Gina tafki mai wutsiya babban aikin injiniya ne wanda ya haɗa ilimin ƙasa, ilimin ruwa, da injiniyan farar hula da na geotechnical. Tsarin yana bin tsari mai ma'ana: zaɓin wuri a hankali, ƙira mai ƙarfi da gina madatsar ruwa, shigar da babban aikin haɗin gwal da tsarin magudanar ruwa, da sadaukar da kai ga tsauraran matakan aiki da kuma ɗorewa na ƙarshe. Ta hanyar tsarin aikace-aikacen ƙa'idodin injiniyan sauti da kuma amfani da kayan haɓaka kamar geomembranes, GCLs, da geocells, masana'antar hakar ma'adinai na iya gina wuraren da suka dace da buƙatun buƙatun aiki biyu da kariyar muhalli na dogon lokaci.