Họrọ asụsụ:
Lucas Rojas Mendoza, ST Equipment & Technology, USA
lrojasmendoza@steqtech.com
Frank Hrach, ST Equipment & Technology, USA
Kyle Flynn, ST Equipment & Technology, USA
Abhishek Gupta, ST Equipment & Technology, USA
ST Equipment & Technology LLC (STET) azụlitewo a akwụkwọ nhazi usoro dabeere na tribo-electrostatic belt nkewa na-enye ịnweta nhazi ụlọ ọrụ a iji beneficiate ezi ihe na ihe ume-oru oma na kpamkpam akọrọ technology. In contrast to other electrostatic separation processes that are typically limited to particles >75μm na size, na STET triboelectric belt separator na-ruru eru maka nkewa nke nnọọ mma (<1μm) ka moderately Ntụ (500μm) ahụ, na nnukwu elu throughput. The STET tribo-electrostatic technology has been used to process and commercially separate a wide range of industrial minerals and other dry granular powders. Ebe a, bench-scale results are presented on the beneficiation of low-grade Fe ore fines using STET belt separation process. Bench-scale testing demonstrated the capability of the STET technology to simultaneously recover Fe and reject SiO2 from itabirite ore with a D50 of 60µm and ultrafine Fe ore tailings with a D50 of 20µm. The STET technology is presented as an alternative to beneficiate Fe ore fines that could not be successfully treated via traditional flowsheet circuits due to their granulometry and mineralogy.
Iron ore bụ nke anọ kasị mmewere na ụwa jikọrọ ọnụ [1]. Iron dị oké mkpa ka ígwè n'ichepụta ya mere ihe dị oké mkpa ihe n'ihi na zuru ụwa ọnụ aku development [1-2]. Iron na-n'ọtụtụ ebe na-ewu na n'ichepụta nke ugbo ala [3]. Ọtụtụ n'ime ígwè ore ego na-ekewet nke metamorphosed kee ya agbụ ígwè formations (BIF) na nke ígwè na ọtụtụ ndị na-hụrụ na ụdị oxides, hydroxides na a nta ruo n'ókè carbonates [4-5]. A ụdị ígwè formations na elu carbonate ọdịnaya bụ dolomitic itabirites nke bụ a ngwaahịa nke dolomitization na metamorphism nke BIF ego [6]. The kasị ibu ígwè ore ego na ụwa nwere ike dị na Australia, China, Canada, Ukraine, India na Brazil [5].
The chemical mejupụtara nke ígwè ores nwere ihe yiri mbara nso na chemical mejupụtara karịsịa maka Fe ọdịnaya na metụtara gangue minerals [1]. Isi ígwè minerals jikọtara kasị ígwè ores bụ hematite, goethite, limonite na magnetite [1,5]. Isi contaminants na ígwè ores bụ SiO2 na Al2O3 [1,5,7]. Ahụkarị silica na alumina amị minerals ugbu a na ígwè ores bụ quartz, kaolinite, gibbsite, diaspore na corundum. N'ime ndị a ọ na-emekarị kwuru na quartz bụ pụtara silica amị ịnweta ma kaolinite na gibbsite bụ abụọ-isi alumina agba minerals [7].
Iron ore mmịpụta na tumadi rụrụ site emeghe olulu Ngwuputa arụmọrụ, n'ihi na ịrịba tailings ọgbọ [2]. The ígwè ore mmepụta usoro na-agụnyekarị atọ: Ngwuputa, nhazi na pelletizing eme. ndị a, nhazi ana achi achi na ihe zuru ezu ígwè ọkwa na onwu na-enweta tupu pelletizing ogbo. Nhazi agụnye ndinuak, nhazi ọkwa, egwe ọka ma na ịta aiming na-amụba ígwè ọdịnaya mgbe mbenata ego nke gangue minerals [1-2]. Onye ọ bụla ịnweta ego nwere ya pụrụ iche e ji mara na-akwanyere ígwè na gangue agba minerals, ya mere ọ na-achọ a dị iche iche ịta Usoro [7].
Magnetik nkewa na a na-eji na beneficiation nke elu ọkwa ígwè ores ebe kasị ígwè minerals na-ferro na paramagnetic [1,5]. Wet na akọrọ ala-osisi ike magnetik nkewa (LIMS) usoro na-eji hazie ores na ike magnetik Njirimara dị ka magnetite mgbe udu mmiri elu-osisi ike magnetik nkewa na-eji ikewara Fe-amị minerals na-adịghị ike magnetik Njirimara dị ka hematite si gangue minerals. Iron ores dị goethite na limonite ọtụtụ ndị na-hụrụ na tailings na anaghị ikewapụ nke ọma site ma Usoro [1,5]. Magnetik ụzọ ugbu nsogbu na usoro nke ha ala akọ na na okwu nke chọrọ iji ígwè ore inwe susceptible magnetik n'ubi [5].
Flotation, n'akụkụ aka nke ọzọ, a na-eji belata ọdịnaya nke adịghị na ala-ọkwa ígwè ores [1-2,5]. Iron ores nwere ike lekwasị ma site kpọmkwem anionic flotation ígwè oxides ma ọ bụ laa azu cationic flotation nke silica, Otú ọ dị laa azu cationic flotation anọgide ndị kasị ewu ewu flotation uzo eji ígwè ụlọ ọrụ [5,7]. The ojiji nke flotation ya oke site na-eri nke reagents, ọnụnọ nke silica na alumina-ọgaranya slimes na ọnụnọ nke carbonate minerals [7-8]. Ọzọkwa, flotation achọ n'efu na mmiri ọgwụ na ojiji nke downstream dewatering akọrọ ikpeazụ ngwa [1].
The ojiji nke flotation maka ịta nke ígwè na-agụnye desliming ka sere n'elu na ọnụnọ nke Iwu na-arụpụta na-ebelata arụmọrụ na elu reagent akwụ ụgwọ [5,7]. Desliming karịsịa oké egwu maka iwepụ alumina ka nkewa nke gibbsite si hematite ma ọ bụ goethite site ọ bụla n'elu-arụsi ọrụ ike mmadụ bụ nnọọ ihe siri ike [7]. Ọtụtụ n'ime alumina amị minerals pụtara na mma size nso (<20um) allowing for its removal through desliming. n'ozuzu, a high concentration of fines (<20um) and alumina increases the required cationic collector dose and decreases selectivity dramatically [5,7].
Ọzọkwa, the presence of carbonate minerals – such as in dolomitic itabirites- can also deteriorate flotation selectivity between iron minerals and quartz as iron ores containing carbonates such as dolomite do not float very selectively. Dissolved carbonates species adsorb on the quartz surfaces harming the selectivity of flotation [8]. Flotation can be reasonably effective in upgrading low-grade iron ores, but it is strongly dependent on the ore mineralogy [1-3,5]. Flotation of iron ores containing high alumina content will be possible via desliming at the expense of the overall iron recovery [7], while flotation of iron ores containing carbonate minerals will be challenging and possibly not feasible [8].
Modern processing circuits of Fe-bearing minerals may include both flotation and magnetic concentration steps [1,5]. Dị ka ọmụmaatụ, magnetic concentration can be used on the fines stream from the desliming stage prior to flotation and on the flotation rejects. The incorporation of low and high intensity magnetic concentrators allows for an increase in the overall iron recovery in the processing circuit by recovering a fraction of the ferro and paramagnetic iron minerals such as magnetite and hematite [1]. Goethite is typically the main component of many iron plant reject streams due to its weak magnetic properties [9]. In the absence of further downstream processing for the reject streams from magnetic concentration and flotation, the fine rejects will end up disposed in a tailings dam [2]. Tailings disposal and processing have become crucial for environmental preservation and recovery of iron valuables, karị, and therefore the processing of iron ore tailings in the mining industry has grown in importance [10].
Clearly, the processing of tailings from traditional iron beneficiation circuits and the processing of dolomitic itabirite is challenging via traditional desliming-flotation-magnetic concentration flowsheets due to their mineralogy and granulometry, and therefore alternative beneficiation technologies such as tribo-electrostatic separation which is less restrictive in terms of the ore mineralogy and that allows for the processing of fines may be of interest.
Tribo-electrostatic nkewa utilizes eletriki ụgwọ ọdịiche dị n'etiti ihe na-emepụta site n'elu kọntaktị ma ọ bụ triboelectric Nchaji. Na simplistic ụzọ, mgbe abụọ ihe ndị na kọntaktị, the material with a higher affinity for electron gains electrons thus charges negative, mgbe ihe onwunwe na ala elektrọn mmekọrita ebubo mma. Na ntọala, low-grade iron ore fines and dolomitic itabirites that are not processable by means of conventional flotation and/or magnetic separation could be upgraded by exploiting the differential charging property of their minerals [11].
Here we present STET tribo-electrostatic belt separation as a possible beneficiation route to concentrate ultrafine iron ore tailings and to beneficiate dolomitic itabirite mineral. The STET process provides the mineral processing industry with a unique water-free capability to process dry feed. The environmentally friendly process can eliminate the need for wet processing, downstream waste water treatment and required drying of final material. Na mgbakwunye, The STET usoro achọ obere tupu ọgwụgwọ nke ịnweta ma na-arụ ọrụ na elu ikike - ruo 40 aj u kwa hour. Oriri ike bụ ihe na-erughị 2 kilowatt-awa kwa ton nke ihe onwunwe esichara.
Materials
Abụọ ezi ala-ọkwa ígwè ores-eji nke a usoro nke ule. The mbụ ore gụnyere ihe ultrafine Fe ore tailings sample na a D50 of 20 μm na nke abụọ sample nke ihe itabirite ígwè ore sample na a D50 of 60 μm. Ma samples siere ha n'oge ha beneficiation na-apụghị rụọ ọrụ nke ọma esichara site omenala desliming-flotation-magnetik ịta na sekit na sekit ruru ha granulometry na mineralogy. Ma samples e nwetara site na Ngwuputa arụmọrụ ke Brazil.
The mbụ sample bụ enwetara site na otu dị na desliming-flotation-magnetik ịta circuit. The sample e anakọtara site na a tailings dam, mgbe Fikiere, homogenized na juru n'ọnụ. The abụọ sample bụ site na itabirite ígwè kpụọ na Brazil. The sample e gburu na ota site size na ezigbo akụkụ enwetara site na nhazi ọkwa ogbo mesịrị wara ọtụtụ nkebi nke desliming ruo mgbe a D98 of 150 μm rụzuru. The sample ahụ mịrị amị, homogenized na juru n'ọnụ.
Urughuru size nkesa (PSD) kpebisiri ike iji a laser diffraction urughuru size analyzer, a Malvern si Mastersizer 3000 E. Ma n'omume na-ji Loss-on-mgbanye(iWU), XRF na XRD. The ọnwụ na mgbanye (iWU) kpebisiri ike site ịtụkwasị 4 grams nke sample na a 1000 ºC oku maka 60 nkeji na-akọkwara ndị LOI na ihe dị ka natara ndabere. The chemical mejupụtara analysis e dechara eji a wavelength dispersive X-ray Fluorescence (WD-XRF) ngwá na isi crystalline n'ụzọ na-nyochaworo site XRD Usoro.
The chemical mejupụtara na LOI maka tailings sample (Tailings), na maka itabirite ígwè kpụọ sample (Itabirite), gosiri na Isiokwu 1 na urughuru size nkesa ma samples na-egosi na Fig 1. Maka tailings ịlele isi Fe recoverable n'ụzọ bụ goethite na hematite, na isi gangue ịnweta bụ quartz (fig 4). Maka itabirite sample isi Fe recoverable n'ụzọ bụ hematite, na isi gangue minerals na quartz na dolomite (fig 4).
Isiokwu 1. N'ihi nke chemical analysis isi ọcha na tailings na Itabirite samples.
| sample | Grade (wt%) | |||||||
|---|---|---|---|---|---|---|---|---|
| Fe | SiO2 | Al2O3 | MnO | MgO | CaO | LOI** | Others | |
| Tailings | 30.3 | 47.4 | 4.3 | 1.0 | * | * | 3.4 | 13.4 |
| Itabirite | 47.6 | 23.0 | 0.7 | 0.2 | 1.5 | 2.2 | 4.0 | 21.0 |
Urughuru Size nkesa
ụzọ
A usoro nke nwere e mere ka ichoputa mmetụta nke dị iche iche kwa na ígwè ije na ma ígwè samples iji STET proprietary tribo-electrostatic belt separator technology. Nlele e duziri iji a bench-ọnụ ọgụgụ tribo-electrostatic belt separator, ndụ zoro dị ka 'benchtop separator'. Bench-ọnụ ọgụgụ ule bụ nke mbụ na-adọ nke a atọ-adọ technology mmejuputa usoro (Lee Isiokwu 2) tinyere bench-ọnụ ọgụgụ nwale, pilot-ọnụ ọgụgụ ule na azụmahịa-ọnụ ọgụgụ mmejuputa. The benchtop separator na-eji maka screening na-egosi nke tribo-electrostatic Nchaji na-ekpebi ma ọ bụrụ na a na ihe onwunwe bụ ezigbo nwa akwukwo maka electrostatic beneficiation. Isi iche n'etiti onye ọ bụla mpempe akụrụngwa na-adade ke Isiokwu 2. Ezie na ngwá eji n'ime onye ọ bụla na-adọ dị iche na size, ọrụ ụkpụrụ bụ fundamentally otu.
Isiokwu 2. Atọ-adọ mmejuputa usoro eji STET tribo-electrostatic belt separator technology
| adọ | eji maka: | Electrode Dimensions (W x L) cm | Type of Process/ |
|---|---|---|---|
| Bench Scale Evaluation | Qualitative Evaluation | 5*250 | ogbe |
| pilot n'ọtụtụ Testing | Quantitative Evaluation | 15*610 | ogbe |
| Commercial Scale Implementation | Commercial Production | 107 *610 | na-aga n'ihu |
STET Operation Kwuru
The ọrụ ụkpụrụ nke separator na-adabere ná tribo-electrostatic Nchaji. Na tribo-electrostatic belt separator (ọgụgụ 2 na 3), ihe a na nri n'ime warara ọdịiche 0.9 - 1.5 cm n'etiti abụọ yiri planar electrodes. The ahụ na-triboelectrically boro ebubo site interparticle kọntaktị. The ghaghị ebubo ịnweta(s) na-ezighị ezi na ebubo ịnweta(s) na-dọtara na-abụghị electrodes. Inside na separator ahụ na-ekpochapụ site a na-aga n'ihu na-akpụ akpụ na-emeghe-ntupu belt na ekekpepde na-abụghị ntụziaka. The belt ka nke plastic ihe na-akpali ahụ n'akụkụ ọ bụla electrode n'ebe abụghị nsọtụ nke separator. The counter ugbu a eruba nke kewara ahụ na nọgide triboelectric Nchaji site urughuru-urughuru collisions enye maka a multistage nkewa na utịp ke magburu onwe-adị ọcha na mgbake na a otu-ngafe unit. The triboelectric belt separator technology e ji mee ikewapụ a dịgasị iche iche nke ihe gụnyere mixtures nke yiri enyo aluminosilicates / carbon (ofufe ash), calcite / quartz, talc / magnesite, na barite / quartz.
n'ozuzu, na separator imewe bụ dịtụ mfe na belt na metụtara rollers dị ka nanị na-akpụ akpụ akụkụ. The electrodes bụ anyịnya na esịnede ihe n'ụzọ kwesịrị ekwesị inogide ihe. The separator electrode ogologo bụ mkpokọta 6 mita (20 ft.) na obosara 1.25 mita (4 ft.) maka zuru size azụmahịa nkeji. The elu belt ọsọ na-enyere nnọọ elu throughputs, ruo 40 ton kwa hour maka zuru size azụmahịa nkeji. The ike oriri bụ ihe na-erughị 2 kilowatt-awa kwa ton nke ihe onwunwe esichara na ọtụtụ ndị ike gwusia site abụọ Motors ụgbọala belt.
Schematic nke triboelectric belt separator
Ihe nke nkewa mpaghara
Dị ka a pụrụ hụrụ na Isiokwu 2, isi ihe dị iche n'etiti benchtop separator na pilot-ọnụ ọgụgụ na azụmahịa-ọnụ ọgụgụ separators bụ na ogologo nke benchtop separator bụ mkpokọta 0.4 ugboro ogologo nke pilot-ọnụ ọgụgụ na azụmahịa-ọnụ ọgụgụ nkeji. Dị ka separator arụmọrụ bụ a ọrụ nke electrode ogologo, bench-ọnụ ọgụgụ ule apụghị-eji dị ka a dochie anya pilot-ọnụ ọgụgụ ule. Pilot-ọnụ ọgụgụ ule dị mkpa iji chọpụta na-ruo n'ókè nke na nkewa na STET usoro nwere ike nweta, na-ekpebi ma ọ bụrụ na STET usoro nwere ike izute ngwaahịa zaa n'okpuru nyere oriri udu. Kama, na benchtop separator a na-eji achị si nwa akwukwo ihe na-eleghi anya na-egosi na ọ bụla dị ịrịba nkewa na pilot-ọnụ ọgụgụ larịị. Results nwetara na bench-ọnụ ọgụgụ ga-ndị na-abụghị kachasị, na nkewa hụrụ bụ ihe na-erughị nke ga-hụrụ na a azụmahịa sized STET separator.
Anwale na pilot osisi dị mkpa tupu azụmahịa ọnụ ọgụgụ nkenye ọnọdụ, Otú ọ dị, ule na bench-ọnụ ọgụgụ na-ume dị ka ndị mbụ na-adọ nke mmejuputa usoro maka ọ bụla e nyere ihe onwunwe. Ọzọkwa, na ikpe nke ihe onwunwe nnweta a na-ejedebeghị, na benchtop separator enye a bara uru ngwá ọrụ maka echetakwa nke nwere ihe ịga nke ọma oru ngo (i.e., oru na nke ndị ahịa na ụlọ ọrụ quality zaa nwere ike zutere iji STET technology).
Bench-ọnụ ọgụgụ ule
Standard usoro ọnwụnwa ndị rụrụ gburugburu kpọmkwem ihe mgbaru ọsọ na-amụba Fe ịta na iji belata ịta nke gangue minerals. Dị iche iche variables na-enyoba jirichaa ígwè ije na-ekpebi ntụziaka nke ije nke dị iche iche minerals. The direction nke ije hụrụ n'oge benchtop testing bụ indicative nke direction nke ije na pilot osisi na azụmahịa ọnụ ọgụgụ.
The variables nyochaworo gụnyere ikwu iru mmiri (RH), okpomọkụ, electrode polarity, belt ọsọ na etinyere voltaji. ndị a, RH na okpomọkụ na naanị nwere ike a nnukwu mmetụta esi tribo-Nchaji na Ya mere na nkewa na-arụpụta. N'ihi ya, kacha RH na okpomọkụ na ọnọdụ kpebisiri n'ihu nchọpụta mmetụta nke ndị fọdụrụ variables. Abụọ polarity etoju na-enyoba: i) n'elu electrode polarity nti na ii) n'elu electrode polarity ọjọọ. Maka STET separator, n'okpuru a nyere polarity ndokwa na n'okpuru kacha RH na okpomọkụ na ọnọdụ, belt ọsọ bụ isi akara ahụ maka optimizing ngwaahịa ọkwa na uka mgbake. Testing na bench separator enyere wụsịrị ìhè na mmetụta nke ụfọdụ arụmọrụ variables na tribo-electrostatic Nchaji n'ihi na a nyere ịnweta sample, na Ya mere nwetara ihe na ọnọdụ nwere ike ji mee, ụfọdụ ogo, warara ala ọnụ ọgụgụ nke variables na nnwale na-rụrụ na pilot osisi ọnụ ọgụgụ. Isiokwu 3 anatara nso nke nkewa na ọnọdụ na-eji dị ka akụkụ nke na-adọ 1 nwale usoro maka tailings na itabirite samples.
Isiokwu 3 depụtara nso nke nkewa ọnọdụ
| Parameter | Units | Range of Values | |
|---|---|---|---|
| Tailings | Itabirite | ||
| Top Electrode Polarity | - | Positive- Negative | Positive- Negative |
| Electrode Voltage | -kV/+kV | 4-5 | 4-5 |
| Feed Relative Humidity (RH) | % | 1-30.7 | 2-39.6 |
| Feed Temperature | ° F (° C) | 71-90 (21.7-32.2) | 70-87 (21.1-30.6) |
| Belt Speed | Fps (m / s) | 10-45 (3.0-13.7) | 10-45 (3.0-13.7) |
| Electrode Gap | Inches (mm) | 0.400 (10.2 mm) | 0.400 (10.2 mm) |
Ule e duziri na benchtop separator n'okpuru ogbe ọnọdụ, na oriri samples of 1.5 lbs. ule. A iwepụ ọsọ iji 1 lb. nke ihe onwunwe ke ẹkenam ke n'agbata ule iji hụ na ihe ọ bụla o kwere omume carryover mmetụta si aga ọnọdụ e atụle. Tupu ule malitere ihe onwunwe bụ homogenized na sample akpa nwere ma na-agba ọsọ na iwepụ ihe onwunwe e kwadebere. Ná mmalite nke ọ bụla nnwale okpomọkụ na ikwu iru mmiri (RH) e tụrụ iji a Vaisala HM41 aka-ẹkenịmde iru mmiri na okpomọkụ nyocha. The iche iche nke okpomọkụ na RH gafee niile nwere bụ 70-90 ° F (21.1-32.2 (° C) na 1-39.6%, karị. Iji nwalee a ala RH na / ma ọ bụ elu okpomọkụ, ndepụta ma iwepụ samples nọ na a ihicha oven na 100 ° C maka ugboro n'etiti 30-60 nkeji. Na ntule ndịiche, elu RH ụkpụrụ omume ndị imezu site na-agbakwụnye obere mmiri na ihe onwunwe, sochiri homogenization. Mgbe RH na okpomọkụ e tụrụ na onye ọ bụla na ndepụta sample, nzọụkwụ ọzọ bụ ka electrode polarity, belt ọsọ na voltaji ahụ chọrọ larịị. Ọdịiche ụkpụrụ omume ndị nọ mgbe nile na 0.4 sentimita (10.2 mm) n'oge ule mkpọsa maka tailings na itabirite samples.
Tupu ọ bụla ule, a obere oriri sub-sample nwere ihe dị 20g e anakọtara (ẹkedọhọde dị ka 'ndepụta'). N'elu mwube niile na ọrụ variables, na ihe onwunwe e nri n'ime benchtop separator site na iji electric vibratory feeder site center nke benchtop separator. N'omume na-anakọtara na njedebe nke ọ bụla nnwale na igwe nke ngwaahịa na njedebe 1 (ẹkedọhọde dị ka 'E1') na ngwaahịa na njedebe 2 (ẹkedọhọde dị ka 'E2') kpebisiri ike iji a iwu na-ahia-agụta ọnụ ọgụgụ. Esonụ ọ bụla ule, obere sub-samples nwere ihe dị 20 g nke E1 na E2 na-anakọtara. Mass zaa ka E1 na E2 na-kọwara:
ebenaE1 na naE2 bụ uka zaa ka E1 na E2, karị; na bụ sample igwe anakọtara na separator ngwaahịa E1 na E2, karị. N'ihi na ma samples, Fe ịta ama ọkọri ngwaahịa E2.
N'ihi na onye ọ bụla set nke sub-samples (i.e., ndepụta, E1 na E2) LOI na isi oxides mejupụtara site XRF kpebisiri. Fe2 The3 ọdịnaya kpebisiri si ụkpụrụ. Maka tailings sample LOI ga na-iko ka ọdịnaya nke goethite na sample ka ọtọ hydroxyl iche iche na goethite ga oxidize n'ime H2 Theg [10]. N'adịghị, maka itabirite sample LOI ga na-metụtara nwere nke carbonates na sample, dị ka calcium na magnesium carbonates ga-amalite irekasị n'ime ha isi oxides n'ihi na ntọhapụ nke CO2g na sub zipụta ha n'usoro sample ọnwụ ibu. XRF chaplet na-akwadebe site agwakọta 0.6 grams nke ịnweta sample na 5.4 grams nke lithium tetraborate, nke e họrọ ruru ka chemical mejupụtara nke ma tailings na itabirite samples. XRF analysis na normalized maka LOI.
N'ikpeazụ, Fe mgbake EFe na ngwaahịa (E2) na SiO2 jụrụ Qna na-gbakọọ. EFe na-pasent nke Fe natara na uche na nke mbụ oriri sample na Qsio2 bụ pasent nke wepụrụ si mbụ oriri sample. EFe na Qna na-kọwara:
ebe Ci,(oriri,E1, E2) bụ normalized ịta pasent maka sub-sample si i akụrụngwa (eg., Fe, sio2)
samples Mineralogy
The XRD ụkpụrụ na-egosi isi ịnweta n'ụzọ maka tailings na itabirite samples na-egosi na Fig 4. Maka tailings ịlele isi Fe recoverable n'ụzọ bụ goethite, hematite na magnetite, na isi gangue ịnweta bụ quartz (fig 4). Maka itabirite sample isi Fe recoverable n'ụzọ bụ hematite na magnetite na isi gangue minerals na quartz na dolomite. Magnetite na-egosi na Chọpụta kasịnụ ma samples. Pure hematite, goethite, na magnetite nwere 69.94%, 62.85%, 72.36% Fe, karị.
D nakawa etu esi. A - Tailings sample, B - Itabirite sample
Bench-ọnụ ọgụgụ nwere
A usoro nke ule na-agbaba na-rụrụ ọ bụla ịnweta sample iji na Ịnwetacha uru ịrụ Fe na usen SiO2 ọdịnaya. Umu anumanu na osisi na-etinye uche na E1 ga-indicative nke a na-adịghị mma Nchaji omume mgbe umu ịta ka E2 ka a mma Nchaji omume. Higher belt gbapụrụ ọsọ ndị mma na nhazi nke tailings sample; Otú ọ dị, ihe nke a na agbanwe naanị e hụrụ na-erughị ya n'ụzọ maka itabirite sample.
Nkezi pụta maka tailings na itabirite samples na-adade ke Fig 5, nke e gbakọọ si 6 na 4 nwere, karị. fig 5 ọnọde nkezi uka mkpụrụ ma onwu maka na ndepụta ma ngwaahịa E1 na E2. Na mgbakwunye, onye ọ bụla ibé ọnọde mma ma ọ bụ ọnụ ke ịta (E2- ndepụta) maka nke ọ bụla sample akụrụngwa e.g., Fe, SiO2 Positive ụkpụrụ na-metụtara na-abawanye na ịta na E2, mgbe na-adịghị mma ụkpụrụ na-metụtara ka a ọnụ ke ịta ka E2.
Fig.5. Nkezi uka zaa na onwu maka nri, E1 na E2 ngwaahịa. Error Ogwe-anọchi anya 95% obi ike etiti oge.
Maka tailings sample Fe ọdịnaya ama ọkọri si 29.89% ka 53.75%, na nkezi, na a uka mkpụrụ naE2 - ma ọ bụ uwa uka mgbake – nke 23.30%. Nke a kwekọrọ na Fe mgbake ( na silica ojuju (QE2 ) ụkpụrụ nke 44.17% na 95.44%, karị. The LOI ọdịnaya ama ọkọri si 3.66% ka 5.62% nke na-egosi na-abawanye na Fe ọdịnaya na-metụtara na-abawanye na goethite ọdịnaya (fig 5).
Maka itabirite sample Fe ọdịnaya ama ọkọri si 47.68% ka 57.62%, na nkezi, na a uka mkpụrụ naE2 -nke 65.0%. Nke a kwekọrọ na Fe mgbake EFe( na silica ojuju (Qsio2) ụkpụrụ nke 82.95% na 86.53%, karị. The LOI, MgO na CaO ọdịnaya mụbara site 4.06% ka 5.72%, 1.46 ka 1.87% na site 2.21 ka 3.16%, karị, nke na-egosi na dolomite na-akpụ akpụ na n'otu ụzọ ahụ Fe-amị minerals (fig 5).
N'ihi na ma samples,AL2 The3 , MnO na P yie ka odori ke otu direction ka Fe-amị minerals (fig 5). Mgbe ọ na-chọrọ ka ibelata ịta nke atọ ndị a umu, na jikọtara ịta nke SiO2, AL2 , The3 , naE2 MnO na P na-kpukpru usen ma samples, na Ya mere ngụkọta mmetụta enweta iji benchtop separator bụ nkwalite na ngwaahịa Fe ọkwa na a ọnụ na contaminants ịta.
n'ozuzu, benchtop ule gosiri ihe àmà nke irè Nchaji na nkewa nke ígwè na silica ahụ. The na-ekwe nkwa ime nnyocha ọnụ ọgụgụ na-arụpụta na-egosi na pilot ọnụ ọgụgụ ule gụnyere mbụ na nke abụọ gafee ga-rụrụ.
Nkwurịta
The ibuo data-atụ aro na STET separator rụpụtara ihe dị mkpa na-abawanye na Fe ọdịnaya mgbe n'out oge mbenata SiO2 ọdịnaya.
Ebe gosiri na triboelectrostatic nkewa nwere ike ịkpata a ịrịba ama mmụba na Fe ọdịnaya, a okwu na uru nke na-arụpụta, na kacha iru Fe ọdịnaya na na na ndepụta chọrọ nke technology dị mkpa.
Iji malite, ọ dị mkpa iji tụlee ihe ndị yiri Nchaji omume nke ịnweta umu ke ma samples. Maka tailings ịlele na isi mmiri di Fe oxides na quartz na ibuo pụta gosiri na Fe oxides lekwasị ka E2 mgbe quartz lekwasị ka E1. Na simplistic ụzọ, ọ nwere ike kwuru na Fe oxide ahụ enwetara a mma ụgwọ na na quartz ahụ enwetara a na-ezighị ezi ụgwọ. Nke a bụ omume na-agbanwe agbanwe na triboelectrostatic ọdịdị nke ma minerals dị ka e gosiri site Ferguson (2010) [12]. Isiokwu 4 na-egosi na ihe yiri triboelectric usoro maka họrọ minerals dabeere inductive nkewa, na na ọ na-egosi na quartz na-emi odude na ala nke na Nchaji usoro mgbe goethite, magnetite na hematite na-emi odude elu ke nsonso. Mineral na n'elu nke usoro ga-agbasaghị na-ana nti, mgbe minerals na ala ga-agbasaghị nweta a na-ezighị ezi ụgwọ.
N'akụkụ aka nke ọzọ, maka itabirite sample na isi mmiri di hematite, quartz na dolomite na ibuo pụta gosiri na Fe oxides na dolomite lekwasị ka E2 mgbe quartz lekwasị ka E1. Nke a na-egosi na hematite ahụ na dolomite enwetara a mma ụgwọ mgbe quartz ahụ enwetara a na-ezighị ezi ụgwọ. Dị ka a pụrụ hụrụ na Isiokwu 4, carbonates na-emi odude ke n'elu nke tribo-electrostatic usoro, nke na-egosi na carbonate ahụ agbasaghị nweta a mma ụgwọ, n'ihi ya kwa, na-lekwasị ka E2. Ma dolomite na hematite na-lekwasị ke otu direction, na-egosi na n'ozuzu mmetụta maka hematite ahụ na ọnụnọ nke quartz na dolomite bụ iji nweta a mma ụgwọ.
The direction nke ije nke mineralogical umu ke ọ bụla sample bụ nke paramount mmasị, dị ka ọ ga-ekpebi karịa iru Fe ọkwa na ike ga-enwetara site na a otu ngafe na iji tribo-electrostatic belt separator technology.
Maka tailings na itabirite samples karịa iru Fe ọdịnaya ga-ekpebisi ike site ihe atọ: i) The ego nke Fe na Fe-amị minerals; ii) kacha nta quartz (SiO2 ) ọdịnaya na ike ga-enweta na; III) The ọnụ ọgụgụ nke contaminants-akpụ akpụ na n'otu ụzọ ahụ Fe-amị minerals. Maka tailings ịlele isi contaminants na-akpụ akpụ na otu direction nke Fe-amị minerals na- Al2 The3 MnO agba minerals, mgbe maka itabirite sample isi contaminants bụ CaO MgO Al2 The3 agba minerals.
| Mineral Name | Charge acquired (apparent) |
|---|---|
| Apatite | +++++++ |
| Carbonates | ++++ |
| Monazite | ++++ |
| Titanomagnetite | . |
| Ilmenite | . |
| Rutile | . |
| Leucoxene | . |
| Magnetite/hematite | . |
| Spinels | . |
| Garnet | . |
| Staurolite | - |
| Altered ilmenite | - |
| Goethite | - |
| Zircon | -- |
| Epidote | -- |
| Tremolite | -- |
| Hydrous silicates | -- |
| Aluminosilicates | -- |
| Tourmaline | -- |
| Actinolite | -- |
| Pyroxene | --- |
| Titanite | ---- |
| Feldspar | ---- |
| quartz | ------- |
Isiokwu 4. O triboelectric usoro maka họrọ minerals dabeere inductive nkewa. Gbanwetụrụ si D.N Ferguson (2010) [12].
Maka tailings sample, na Fe ọdịnaya e tụrụ na 29.89%. XRD data na-egosi na kpagburuibe adọ bụ goethite, sochiri hematite, na Ya mere kacha iru Fe ọdịnaya ma ọ bụrụ na a ọcha nkewa ekwe omume ga-n'etiti 62.85% na 69.94% (nke bụ Fe ọdịnaya nke dị ọcha goethite na hematite, karị). ugbu a, a ọcha nkewa bụ ekwe omume dị ka Al2, The3 MnO na P na-amị minerals na-akpụ akpụ na otu direction ka Fe-amị minerals, ya mere ọ bụla na-abawanye na Fe ọdịnaya ga-eme na onye na-abawanye nke a contaminants. mgbe, dịkwuo Fe ọdịnaya, ego nke quartz na E2 ga na-budata ebelata ruo n'ókè ya chefuo ije nke , MnO na P na ngwaahịa (E2). Dị ka e gosiri Isiokwu 4, quartz nwere ike ịkwụsị iji nweta a na-ezighị ezi ụgwọ, na Ya mere na-anọghị nke ọzọ minerals na-enwe ihe yiri ọjọọ Nchaji omume ya ga-ekwe omume nke ukwu ibelata ya ọdịnaya ngwaahịa (E2) site a ụzọ ngafe na iji triboelectrostatic belt separator technology.
Dị ka ọmụmaatụ, ma ọ bụrụ na anyị na-ewere ya na niile Fe ọdịnaya tailings sample jikọtara ka goethite (FeO(OH)), na na naanị gangue oxides bụ SiO2, Al2The3 na MnO, mgbe Fe ọdịnaya ka ngwaahịa ga-enye site:
Fe(%)=(100-SiO2 – (Al2 The3 + MnO*0.6285
ebe, 0.6285 bụ pasent nke Fe dị ọcha goethite. Eq.4 gosi mpi usoro na-ewe ebe-etinye uche Fe ka AL2The3 + MnO enwekwu mgbe SiO2 mbelata.
Maka itabirite sample na Fe ọdịnaya e tụrụ na 47.68%. XRD data na-egosi na kpagburuibe adọ bụ hematite na Ya mere kacha iru Fe ọdịnaya ma ọ bụrụ na a ọcha nkewa ekwe omume ga-nso 69.94% (nke bụ Fe ọdịnaya nke dị ọcha hematite). Dị ka ọ na e-atụle maka tailings ịlele a ọcha nkewa na-agaghị ekwe omume dị ka CaO, MgO, Al2 The3 agba minerals na-akpụ akpụ na otu direction ka hematite, na Ya mere ntọt Fe ọdịnaya SiO2 ọdịnaya ga-belatara. Anya isi na niile nke Fe ọdịnaya a sample jikọtara ka hematite (Fe2The3) na na naanị oxides dị gangue minerals na- SiO2, CaO, MgO, Al2The3 na MnO; mgbe Fe ọdịnaya ngwaahịa a ga-enye site:
Fe(%)=(100-SiO2-CaO + MgO +Al2The3+MnO+iWU*0.6994
ebe, 0.6994 bụ pasent nke Fe dị ọcha hematite. Ọ ga-chọpụtara na Eq.5 agụnye LOI, mgbe Eq.4 adịghị. Maka itabirite sample, na LOI jikọtara na ọnụnọ nke carbonates mgbe maka tailings sample a na-ejikọta ka Fe-amị minerals.
O doro anya na, ma tailings na itabirite samples ọ bụ ike budata dịkwuo Fe ọdịnaya site na mbenata ọdịnaya nke SiO2; Otú ọ dị, dị ka e gosiri Eq.4 na Eq.5, kacha iru Fe ọdịnaya ga-abụ nanị site na ntụziaka nke ije na ịta nke oxides metụtara ka gangue minerals.
Na ntọala, ịta nke Fe ma samples ike-n'ihu mụbara site n'aka a abụọ ngafe na STET separator na nke CaO,MgO Al2 The3 na MnOagba minerals nwere ike iche na Fe-amị minerals. Dị otú ahụ nkewa ga-ekwe omume ma ọ bụrụ na ọtụtụ n'ime quartz na sample e wepụrụ n'oge a mbụ ngafe. Na-anọghị nke quartz, ụfọdụ nke ndị fọdụrụ gangue minerals ga na nchepụta ụgwọ na-abụghị uzo nke goethite, hematite na magnetite, nke ga-eme na ụba Fe ọdịnaya. Dị ka ọmụmaatụ, maka itabirite sample na dabere na ọnọdụ nke dolomite na hematite na triboelectrostatic usoro (Lee Isiokwu 4), dolomite / hematite nkewa ga-ekwe omume dị ka dolomite nwere ike ịkwụsị na-ana nti na mmekọrita hematite.
Ebe-atụle na na kacha iru Fe ọdịnaya a ntụle ndepụta chọrọ maka technology dị mkpa. The STET tribo-electrostatic belt separator achọ ndepụta ihe onwunwe na-akọrọ na finely ala. Nnọọ obere mmiri nwere ike a nnukwu mmetụta esi tribo-Nchaji na Ya mere na ndepụta mmiri ga-ebelata ka <0.5 wt.%. Na mgbakwunye, the feed material should be ground sufficiently fine to liberate gangue materials and should be at least 100% passing mesh 30 (600 um). At least for the tailings sample, the material would have to be dewatered followed by a thermal drying stage, while for the itabirite sample grinding coupled with, or follow by, thermal drying would be necessary prior to beneficiation with the STET separator.
The tailings sample was obtained from an existing desliming-flotation-magnetic concentration circuit and collected directly from a tailings dam. Typical paste moistures from tailings should be around 20-30% and therefore the tailings would need to be dried by means of liquid-solid separation (dewatering) followed by thermal drying and deagglomeration. The use of mechanical dewatering prior to drying is encouraged as mechanical methods have relative low energy consumption per unit of liquid removed in comparison to thermal methods. About 9.05 Btu are required per pound of water eliminated by means of filtration while thermal drying, n'akụkụ aka nke ọzọ, requires around 1800 Btu per pound of water evaporated [13]. The costs associated with the processing of iron tailings will ultimately depend on the minimum achievable moisture during dewatering and on the energetic costs associated with drying.
The itabirite sample was obtained directly from an itabirite iron formation and therefore to process this sample the material would need to undergo crushing and milling followed by thermal drying and deagglomeration. One possible option is the use of hot air swept roller mills, in which dual grinding and drying could be achieved in a single step. The costs associated with the processing of itabirite ore will depend on the feed moisture, feed granulometry and on the energetic costs associated to milling and drying.
For both samples deagglomeration is necessary after the material have been dried to ensure particles are liberated from one another. Deagglomeration can be performed in conjunction to the thermal drying stage, allowing for efficient heat transfer and energy savings.
The bench-ọnụ ọgụgụ na-arụpụta n'ihu ebe a na-egosi ihe àmà siri ike odori na nkewa nke Fe-amị minerals si quartz iji triboelectrostatic belt nkewa.
Maka tailings sample Fe ọdịnaya ama ọkọri si 29.89% ka 53.75%, na nkezi, na a uka mkpụrụ 23.30%, nke kwekọrọ Fe mgbake na silica jụrụ ụkpụrụ nke 44.17% na 95.44%, karị. Maka itabirite sample Fe ọdịnaya ama ọkọri si 47.68 % ka 57.62%, na nkezi, na a uka mkpụrụ 65.0%, nke kwekọrọ Fe mgbake na silica jụrụ ụkpụrụ nke 82.95% na 86.53%, karị. Ndị a pụta nọ na-agwụ agwụ on a separator na bụ nta ma obere oru oma karịa STET azụmahịa separator.
Ibuo Nchoputa na-egosi na ma tailings na itabirite samples karịa iru Fe ọdịnaya ga-adabere na nke kacha nta iru quartz ọdịnaya. Na mgbakwunye, ọbọ elu Fe akara ule nwere ike kwe omume site a abụọ ngafe na STET belt separator.
The results nke ọmụmụ a gosiri na ala-ọkwa ígwè ore Iwu nwere ike kwalite site STET tribo-electrostatic belt separator. Ọzọkwa-arụ ọrụ n'ụlọ pilot osisi ọnụ ọgụgụ na-atụ aro iji chọpụta ígwè uche ọkwa na mgbake na ike ga-enweta. Dabere na ahụmahụ, ngwaahịa mgbake na / ma ọ bụ ọkwa ga budata melite na pilot ọnụ ọgụgụ nhazi, ka tụnyere bench-ọnụ ọgụgụ ule ngwaọrụ tinye n'ọrụ n'oge ndị a ígwè ore ọnwụnwa. The STET tribo-electrostatic nkewa usoro nwere ike na-enye ịrịba uru n'elu ot nhazi ụzọ maka ígwè ore Iwu.
