An approach to confidently predicting jigging performance

Transcription

1 A ch t cfidty dictig jiggig fmc by V. Didé*, A. ks d G. Lvdy Sysis Btm Mis & Mts sis th AIC Tchgis, which icd th d-bd i-sd AIC jig d td tchgis sch s th igsc ct d dvcd mthmtic mds f th jig css. Btm hv dvd mthdgy f dictig css fmc f jigs fm simifid tstig d mdig, bsd btch qimt mtchd t idsti dsigs. Btch tsts cdctd bty-sc i-sd jigs c css sm btchs f mti, sch s ths btid fm di c sms. Th vty cms fm sig dvcd jig css md, ASTRAD, t ik th sts f btch d ctis jigs. Th btch jig std s vty i this hs b dsigd t b hydicy qivt t th f-sc AIC jig, wig th gti f qivt s shs d sig igsc ct. Lm d fi fs mti hv b std i this it d y fd >1 mm c b tstd d xtctd. Th gb tst cd d fth mdig fcs th sttificti f mti, with mhsis ky scts sch s s sh, fd chctistics d sidc tim. Th sittig f jcts fm cctts is itsf m diffict t dc i btch jiggig; hwv, th ASTRAD md icds sti imfcti md, d th AIC Tchgis hv xtcti systms dtd t ch ty f mti. Ai-sd btch jigs vib i sv ctis d ctb. Thy hv b sd t tt sms fm Asti, Sth Afic d Idi s t f stdis it cssig sig jigs. Ech tst y is vib f vis hysic tstig cds (dsity d chmic yss). Tst wk is fmd cs by cs bsis, d ysd sig dvcd md w vib v th Itt. Sm fdmts f i-sd jiggig cd g with sm f th fts f AIC jigs. Th css f dsigig hydicy qivt btch jig tst is th dscibd. Sm sts fm jiggig tsts std s th sts f th ASTRAD dvcd jig md, which ws fist dvd t th KMRC with fs s d c d is w big std d fth dvd d tiizd by Btm. cst d dcd yid tiv t ds mdim csss Th biity t tt s qiig ct dsitis high th SG f 4.0 hysic chctistics f th tht mk hvy mdim sti sitb (f xm, cctb mdi ss i mcscic s). Th is t st div twds th s f i-sd jigs f th bficiti f fs s. This is bcs i-sd jigs cb f gtig th g s mitds qid t fidiz d bd f hvy ticy m i mgs. Dsciti f i-sd jigs Dtid dscitis f th fts f th vis i-sd jig dsigs c b btid fm vds. Hwv, th fdmt ici f i-sd jiggig is th ijcti f w-ss i (<1 b) it chmb with bs, t cct th wt cm thgh th bd f mti big jiggd. Th tw wys i which this ici is immtd (s Fig 1). Eith th i ckt s css th width f th jig bw th sc dck, it is ctd t sid f th jig bd. Th fist immtti is kw s d-bd std jig d th scd s sid std Bm jig. Tw qstis ft skd: Why s i istd f sm mchic ctt? d Why s g vms f bw i istd f cmssd i hydics? Bckgd d histy Th jiggig f fs t dc highgd dcts hs b ctisd f my dcds. Th ss f chsig jiggig bf th csss might icd m f th fwig: A tivy sy sti A bfici td-ff btw tig * Btm Mis & Mts. A Cstig with Btm Mis d Mts Btm Mis & Mts, th Th Sth Afic Istitt f Miig d Mtgy, SA ISSN X/ This ws fist bishd t th SAIMM Cfc, DMS d gvity cctti tis d tchgy i Sth Afic, y Th f Th Sth Afic Istitt f Miig d Mtgy VOLUME 106 NON-REFEREED AER NOVEMBER

2 A ch t cfidty dictig jiggig fmc Fig 1 Sctis thgh tw tys f i-sd jig Th sw t th fist is simy tht th istts w qid t cct th wt cm t th qid vcity is vy high v sht id. A bw syig i t civ ts ctisy t sb vg w dw. Th sw t th scd is tht f giv w qimt, bw is si t miti th cmss hydic ck. Chgs Th chg f miig cmis wishig t s jiggig t bficit thi is tht th i dsity distibti xtds sigificty byd SG f 4, which is th ct imit f hvy iqid stis. This mks it imssib t migfy dict th fmc f jigs sig titi cvs d dsity distibtis gtd by hvy iqids. I dditi, s dd-shd tics bhv vy diffty i hvy iqids d i jigs. Th idictiv fmc f tic is thf hd t dict fm sch ifmti. A bvis sw is t sbjct th sm t jiggig. This is, hwv, ss sim th it might fist. Tw mj jig mts ffct th st f jiggig tst. Thy : th sh f th s, d th id f tim v which th sm is sd. s sh is bd tm sd t dscib my thigs; t mti fw: Th mitd f th s Th fqcy f th s Th shss f th s tyicy fig t th ccti f th wt cm t th bgiig f th s its dviti fm sisid sh. id f tim fs t th sidc tim f th i th jig bd. With th s sh st ccty f timm sttificti t, it is sti cssy t vid gh sidc tim (jig width, dth, gth) t s th diffict mti (fi d gvity mtis) hs tim t migt t th xctd y i th bd. It hs b fd tht chgig th s sh ffcts th t f sti d th qity f th sti. Usy t d qity chgs wk gist ch th d sccssf cmmci jig ss s sh tht givs cctb sti i cmicy fsib sidc tim. A xt chg f th dc is thf t sct with cfidc jig tchgy tht is y sizd d ffs th dqt s sh t s mximm fmc d fxibiity. Th s f xistig jig(s) my wt t chck dict fmc chgs wh fd vis wh it is itdd t bd s. Th chg f th tchgy vid is t tk dt fm bty tsts d dict th fmc f ctis jigs. Th tti f gttig th i-sd jig dsig wg is g wh gic jigs, sch s mchic jigs, sd t fm th tst wk. Awig t g t sht sidc tim, s sh, hs gtiv imictis. By wy f istti, th g f sidc tims (dtmid by s f sti) td i xistig i jigs vis by fct f tw. Th qimt tiizd (wht ty f btch jig t s?), th ittti f th btch tst sts (th vis y dsitis d ssys) d th cct itsf f sig btch jiggig, c ct ctity tht ds t h t dict cfidty jig fmcs. Th ivtiv stis t jig fmc dicti ASTRAD, dtid jig mdig d ysis A sti is t s th ASTRAD md t simt th sttificti i ctis jig bd. ASTRAD is dscibd i dti swh1,2. Th dymic sti i ctis jig diffs i vis scts fm th sti i btch jig. Th mst bvis is tht t ys i ctis jig tv fm th fd d t th vfw wi vy idy. Th sidc tims f ight tics thf vy sht tiv t th vg sidc tim. Cvsy, th w ys tv vy swy, which givs thm mch g sidc tim th th vg. 734 NOVEMBER 2006 VOLUME 106 NON-REFEREED AER Th f Th Sth Afic Istitt f Miig d Mtgy

3 A ch t cfidty dictig jiggig fmc T cct f this bhvi sig dt fm btch jig qis igs mdig ch. Sch ch ws dvd t th KMRC i stdy f Asti cit. Th md is kw s th ASTRAD (Advcd Sttificti Tst Rt Ad Diffsi) md. Btm is fdig th ctid dvmt f this md d hs stbishd th cstcti f th qimt d th cds t s this md. ASTRAD is immtd i Exc itfc i fm ccssib t Btm cits thgh Itt ik t th ASTRAD sv. ASTRAD is mthmtic md f dictig bth th t f sttificti d timt sti f s by dsity d siz i jig. It is ctic mthd f cmbiig miic sts with simifid hysic sti icis. It vids bst d id ccti fmwk f ittig, mss bcig, xttig d scig jig tst wk dt fm sm bty btch jigs thgh t it t tsts d v f-sc idsti jigs. Nms dfid mts dscibig th fd d sidc tim (jig dimsis) tk it cct by th md qtis. Th fcs ctig tics i th jig bd (s Fig 2) smmizd by th tw mi vib mts i ASTRAD: mbiity cfficit, d diffsi cfficit. A ti sis f sttificti tsts f kw fd wshbiity v th cmt g f sidc tims i th jig c sy b smmizd with jst ths tw vib mts. Ths mts dtmid ith by tst wk fm histicy simi wshbiity dt d w th ccti f th fwig sts: titi cvs (sit t dct s fcti f dsity) Gd/cvy cvs (vidd th dsity gd tishi is kw) ig ccity s fcti f th bv cvs d jig dimsis Wht if scis wht if th fd t icss by 10%? wht if th qity dgds by 5%? tc. O f th mi fts f ASTRAD is th biity t dtmi imvmts i jig yid s fcti f jig siz d fd t, which mits cmicy timm jig siz t b sctd. It c s dtmi th g f yids chivb v bdy, which hs vib bt kw wshbiity (dsity distibti), icdig bds. ASTRAD is sd i th tstig d dsig css f jigs s isttd i Fig 3. Th ky fcts i dtmiig th jig ccity f giv thf: Fig 2 Th vis fcs ffctig sttificti i jig bd Fd wshbiity Lbty btch ASTRAD it ctis Idsti ctis titi cvs Gd yid Md mts ig ccity Sttificti tsts Histic dt Wht if scis Fig 3 Th ctxt i which ASTRAD is sd t dict jig fmc Th f Th Sth Afic Istitt f Miig d Mtgy VOLUME 106 NON-REFEREED AER NOVEMBER

4 A ch t cfidty dictig jiggig fmc Rsidc tim f tics i th jig ( fcti f fd t d jig dimsis) Th dsity (d siz) g f th dct d jct cmts f th fd Th sti d mixig t dtmid by th jig s. Th dsig siz f th jig is chs t bst mtch th sidc tim i th jig with tht qid f th mti i th bd t ch qiibim (mximm sti). Th ti it f th jig s is st t mximiz th sti t whi miimizig th tbt mixig ffcts. A xm f this ccti is shw bw i Fig 4. Th ASTRAD md hs w b tstd d sd mtis v wid g f dsitis, fm c t i, i siz gs fm 0.5 mm t 100 mm, with m dt big ddd diy; th imit ASTRAD is sy dtmid by th vibiity f dqt wshbiity dt. Th Fig 5 istts th gd fit btw ASTRAD dicti, md big ifmd with c wshbiity, d th it tst which ws d ittd y by y. Th Aic btch jig Th ivtiv sti i tms f hdw tht hs b dtd by Btm is t bid jig tht is hydicy qivt t cmmci i-sd jig. t simy, jig tht wd b scd dw i scts wd giv s tht is scd dw i scts. Wht is qid is bdy sh i which, cmd t cmmci it: Th tw i-iqid itfcs (bv th bd d i th i skit) th sm vtic discmt fm ch th Th th gth f th wt fm itfc t th th is th sm Th tiv f th wt th s fcti f th th gth is th sm. dct gd Fd Udsizd jig Ccty sizd jig Ovsizd jig Hvy iqid st Fig 4 A xm f ASTRAD dictis sd t simt jigs Mss fcti cvd t dct Cctti MODEL Cctti TEST Bd hight Bd hight Fig 5 Cmis i sttificti, ASTRAD dicti vss tst, jiggig c 736 NOVEMBER 2006 VOLUME 106 NON-REFEREED AER Th f Th Sth Afic Istitt f Miig d Mtgy

5 A ch t cfidty dictig jiggig fmc Ai vvs (Itk/xhst), igsc LC ctd Ai i Bd tb Fixd sc Hight s i idsti jig Ai ckt Fig 6 Th btch Aic d-bd sd jig d its gy with th Aic jig I dditi, th i iig it th i skit z mst b f simi ti t th cmmci it d th i ss sd mst b th sm. Th icis f ths scig citi shw i Fig 6. Th Aic -TUB btch jigs ( -Tb Ud Bd sd btch jig) Tw sizs f sm tyicy std f jiggig sm sight tst sms d g bk sms qiig sti i t fth tst wk. Th -TUB jig is sizd t tt sm sms d s g sms qi mti btchs t b ttd d cmbid. Th jig hs bd dimt f bt 300 mm d c tt m bds t 400 mm d, givig bk btch vm f 30 its, thgh vms f d 22 t 25 its fb. This mks it id f ttig cshd b c sms. Th fist -TUB ws bit i 2002 d cmmissid with fi i fm SA. I 2004 scd -TUB jig ws bit d sd t cdct tst wk Asti. This t tst wk ws iciy qid t gt hysic sms f cctt f chmic ysis. Lys w xtctd fm sm timd tsts s th ASTRAD mthdgy, bt w fd t hv s dsity distibti. This ws t fd t b st f s fcti tht td t middigs bt ws f high gd d cd b icdd i th dct. I 2006 tsts big sig th -TUB jig f i, with th tb dditi f th igsc ct s Btm idsti jigs, t ct d stbiiz th s t th dsid sh d v. Th dsid tt fm btch jig tst is sis f ys f mti, fm th t t th bttm f th jig. Th xtcti f ths ys ticy with m i c b bis d sw. Th mthd tht is sd with th Btm btch Aic jig is t xtct th mti by ms f vcm xtct. Th ys s gtd, c b sd t cct ximt gd-cvy cv f th big tstd, bt th m shistictd tchiqs vib d d ctis dvmt t Btm. Rqid its f ASTRAD tiizti i btch tsts As with y md, th tt is y s gd s th it. F th ASTRAD md th fwig its qid: Siz by dsity distibti f th fd Chmic yss f ch siz by dsity fcti Bk msd dt fm sis f timd btch tsts (dsitis d ssys). F itm 1, it is ssib t s hvy iqid ysis bt, giv th mt f mti i fs s bv dsity f 4, it is fb t fm idivid tic yss. Nt tht ct wk hs dmsttd i scific css tht fd dsity distibti cd b bck cctd by ASTRAD fm sis f btch tsts t difft sidc tims. This is sd t th cmm cd sig ifiit sidc tim which wi wys d dict th shss f th ft d siks cv, v with th bst ssib s. It my w b ssib t s ASTRAD with cfidc wh th y fw ft d siks dt vib t st th ti cv. I th st mthd, btch tsts cdctd f vis dtis (stdd cd dtd t ch cs). Aft ch tst, th bd is xtctd i ys d ch y is scd. Th bk dsity f ch sm is dtmid (sy by wighig i i d wt), d ssys my s b dtmid. This dt is th sd t fit th ASTRAD md mts which dfi th ss f th jig with tic s sh t th ty. Simtis c th b sig y ths md mts f stimtig chgs i dct d t chgs i fd wshbiity d sidc tim. As sid visy, it is fb t s btch jig whs sig chctistics wd b cs t jig i d t fd th md with dt f xistig jig s vt s ssib. ASTRAD md mts my b scd t th w s chctistics bsd histic dt bt it wi wys b m cti th scig btw jigs with simi s chctistics. Th f Th Sth Afic Istitt f Miig d Mtgy VOLUME 106 NON-REFEREED AER NOVEMBER

6 A ch t cfidty dictig jiggig fmc Rsts fm ASTRAD simti, cibtd by btch tsts i s Figs 7 d 8 shws th fit btw th cibtd ASTRAD md, d sttificti dt f difft sidc tims i btch jig (MDS) d AIC it jig sd i btch md. Th bty btch tsts w fmd with 80 t 100 kg f i s f cs d fi fctis, t f difft sidc tims t dtmi th migti f tics fm y t y with tim s fcti f thi dsity. Ath sis f btch tsts ws fmd i f sc it jig, with th fd mti hmgsy distibtd i th bd by hd. Th bd ws th jiggd f sctd sidc tims i d t cct dt fm btch tsts d tig cditis i tm f s sh, wd wt fw, sc dck t, tc. Th sts std gh i Figs 7 d 8, s th dictd vss msd dsity i th jig bd. Ech it th gh is msd dsity f siz fcti (h, -8 mm) fm f th vis ys t difft hights i th btch it f vis ids f sti tim. Th ASTRAD md smmizs th ti g f tsts with jst tw mts. Of cs my m ghs st fm th md shwig viti f dsity d siz distibti i th jig bd with bd dth d sidc tim. Th imfcti f th fit tsts it mximm dvitis f bt 5% t ys dsitis f 4.0 d bt 3.5% t ys dsitis f 3.0. Rsts fm ASTRAD simti, cibtd by it tsts i s Th xt tsts w fmd i ctis Aic jig. Fig 8 shws th ASTRAD md fittd t y dt fm csh st f fis (-3 mm) tst wh y dsitis w msd v th hight f th bd d g th gth f th jig. Th ctis tst vids simi s chctistics t g idsti jig, d th it jig csms bt 10 t/h f i, fis, sms d my, th t vis ccitis t gt dt, h s with vis sidc tims. Th fit shws mximm dvitis f 3.5% t bt 6% t ys dsitis f 4.0/4.5 d f bt 5% t w dsitis. This idicts tht th ASTRAD simti dicts th dsity i th vis ys s ccty i ctis s i btch md. Mv, this dmstts tht this tstig d mdig mthd c dict ccty which dsity ( gd) fi t xct i jig bd, which ds t dict ccti f th sttificti d jiggig fficicy s fcti f jig ccity d wshbiity. Oth tiiztis f ASTRAD simti, cibtd by btch it tsts Th bv bvis fist icti is t sct it tst chctistics (siz fcti, ccity, jig dimsis, tc.) bsd sim btch tsts. Of cs, imiy btch tsts wd s hv cfimd th sid mti ws jigb. Oc th ASTRAD md is cibtd with tst dt, tmds ssibiitis xist t dstd th csqcs f jig ccity d fd chgs th t d qity f th dct. Ths stdis c xtt sigificty fm th fd qity cty sd i th dyig btch tsts, d t jigs f widy vyig ccity. My cs stdis c b csidd wh giig jiggig t, s isttd i Fig 9. A stdy sig ASTRAD ws cdctd wh it ws fd tht by bidig 25% xt ccity it th jig bdy byd iiti dsig ccity, ths jigs wi tyicy tfm by ximty dictd y dsity Act y dsity MDS d Aic it (kg/m3) Fig 7 Fit btw ASTRAD dictd ys dsity d ct btch tst s dsity 738 NOVEMBER 2006 VOLUME 106 NON-REFEREED AER Th f Th Sth Afic Istitt f Miig d Mtgy

7 A ch t cfidty dictig jiggig fmc dictd y dsity Act y dsity MDS d Aic it (kg/m3) Fig 8 Fit btw ASTRAD dictd y s dsity d ct it tst s dsity Act yid mis dsig yid (% t dsig gd) ig siz =Nmi ccity ig siz = 1.25 * Nmi Fig 9 Yid ss vss fd t f difft sizd jigs dsity Fd t t dsig fd t ti 1.5% th bst yid t tgt gd d dsig fd t. Fth, wh fd t 25% bv dsig fd t (fmc d ws th qtifid), th g btw th tw dsigs icsd t bt 2% yid, with f cs th m bst ss f th csvtiv dsig. Ths vs thgh -gigib w tyic figs d shwd tht jigs w fiy w sizd t fist. Sch stdy c tk c bf csty it tsts visgd. It s ws th stdy f th ifc f fd chctistics d thght f dy tig jig t. Cibti f th md tks c fist, fm ith btch jig dt fm th ct idsti jig. Th fd mts d th sidc tim i th md c b vid t wi t mk dictis f hw th jig fmc wi chg d difft scis f fd t d qity. A immdit icti is t dict jig fficicis with fd bds. This c b d t t dsig stg i xistig t, wh th t wishs t his dcti i ticiti f cssig fds difft fm th s. O f th mst xcitig ictis is th ssibiity t s th ASTRAD md d th bk y tis msd fm timd btch jig tsts, s itd t i, t cct th qivt ft d siks ysis f th fd mti; this is th fd tht th md qis i d t ccty dict th timd btch sts, icdig th timt tst tht vis fm ft/sik dt by ifficicis i th jiggig css. Th xct fit btw th ASTRAD md d ct sttificti wd th vid sigifict tity t iby stimt ft d siks dt fm sim jig btch tsts. Rct wk idictd tht this shd b ssib, vig th sbjct f fth stdy. Rfcs 1. Th ASTRAD jig sttificti md, Btm Mis d Mts ft th AIC Tchgis, jiggig@btmbv.cm 2. ONKERS, A., LYMAN G.., d LOVEDAY G.K., Advcs i mdig f sttificti i jigs, XIII Itti C ti Cgss, 1998, G2, v. 1, , Bisb, Asti. Th f Th Sth Afic Istitt f Miig d Mtgy VOLUME 106 NON-REFEREED AER NOVEMBER