Reducing accidents in the mining industry an integrated approach

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1 Syopi Reducig ccidet i the miig iduty itegted ppoch by J.C. Je* d A.C. Bet* The pltium miig iduty h expeieced igifict icee i ftl ccidet. Mie ccidet e i piciple pevetble, d thee i eomou peue o employe to evee thi ted. Thi ppe eview fety mgemet ytem (SMS) well behviou-bed fety (BBS). Bed o the eview, SWOT lye e pefomed o the SMS d BBS pocee d model of itegted fety mgemet ytem (ISMS) i itoduced. A umbe of ftl ccidet i lyed to idetify fcto tht cotibuted to ccidet i the miig iduty. Theefte the potetil wekee of SMS of pltium mie e expoed d the potetil beefit of implemetig the ISMS fo thi ce tudy e demotted. o the employe. Employe deped get del o fety mgemet ytem (SMS) i thei edevou to elimite ufe coditio. Thi, howeve, doe ot effectively dde t-ik behviou tht, ccodig to Schutte3, cotibute to 88% of wokplce ccidet. To combt thi thet, my ogiztio e implemetig wht i efeed to behviou-bed fety (BBS) pogmme. The pupoe of thi eech poject w to develop itegted fety mgemet ytem (ISMS), which icopote the pect of BBS with covetiol fety mgemet pctice. Litetue eview T c t i o P p e Sfety mgemet ytem Itoductio Ftl ccidet i the Noth-Wet miig egio of South Afic hve iceed igifictly ice 1999 (ee Figue 11). Duig 2002 the Noth-Wet egio expeieced the wot eve ye i tem of totl ftlitie, which i oe idicto of fety pefomce*. The ftlity te (deth pe employee) iceed fom 0.61 i 2001 to 0.86 i I 2003 it w gi Howeve, the pltium iduty, which i motly bed i the Noth-Wet Povice, h bee expdig i the pt few ye d i ubequetly fcig the ik ocited with iceed miig depth well loge tmmig ditce. Figue 2 how the umbe of ftl ijuie ocited with pltium mie i South Afic1. While expio i citicl fo employmet d ecoomic gowth i South Afic, it cot be doe t the expee of helth d fety. Ude the Mie Helth d Sfety Act (MHSA)2, the pimy epoibility fo euig helthy d fe eviomet et *It mut be oted tht thee e othe idicto of fety pefomce, e.g. dy lot, d omlizig goup of idicto would povide fo moe meigful compio of fety pefomce The Itetiol Lbou Ogitio (ILO) h developed voluty guidelie4 tht ought to cotibute to the fegudig of woke fom hzd log with the elimitio of wok-elted ijuie, ill helth, diee, icidet d deth. Howeve, it i ecey to etblih occuptiol fety d helth (OSH) policie to povide diectio fo deciio-mkig though fomlized fety mgemet ytem (SMS). Hemu5 emphize the impotce of ivolvig woke d thei epeettive diectly i the OSH deciio-mkig poce. The ecey OSH competece equiemet mut be defied d gemet etblihed d mitied to eue tht ll peo e competet to cy out the fety d helth pect of thei dutie d epoibilitie. Meuble pecific OSH objective coitet with the OSH policy hould be etblihed fo the ogiztio. Thee objective hve to be coitet with elevt d pplicble tiol lw d egultio, well the techicl d buie obligtio of the * Deptmet of Egieeig d Techology Mgemet, Uiveity of Petoi, Petoi. The South Afic Ititute of Miig d Metllugy, SA ISSN X/ Ppe eceived J. 2005; evied ppe eceived Sep The Joul of The South Afic Ititute of Miig d Metllugy VOLUME 105 REFEREED PAPER NOVEMBER

2 Reducig ccidet i the miig iduty itegted ppoch Figue 1 Numbe of ftlitie i the Noth-Wet egio of South Afic Figue 2 Numbe of ftlitie i South Afic pltium mie ogiztio with egd to OSH. Hzd d ik to the fety d helth of woke hould be idetified d eed o ogoig bi. Pevettive d potective meue hould be implemeted i the followig ode of pioity6: Elimite the hzd/ik Cotol the hzd/ik t ouce, though the ue of egieeig cotol o ogiztiol meue Miimize the ik/hzd by the deig of fe wok ytem, which iclude dmiittive cotol meue Whee eidul hzd/ik cot be cotolled by collective meue, the employe hould povide fo ppopite peol potective equipmet d implemet meue to eue it ue d mitece. The impct o OSH of itel chge, uch thoe i tffig o due to ew pocee o wokig pocedue, well extel chge, fo exmple eult of medmet of tiol lw o developmet i techology, hould be evluted d ppopite pevettive tep tke to mitigte ik pio to the itoductio of chge. Emegecy pevetio, pepede d epoe gemet hould be etblihed d mitied. Pocuemet pocedue hould be etblihed d mitied to eue tht complice with fety d helth equiemet fo the ogiztio i idetified, evluted d icopoted ito puchig d leig pecifictio. Agemet hould lo be etblihed d mitied fo euig tht the fety d helth equiemet of the ogiztio e pplied to cotcto d thei woke. Pocedue to moito, meue, d ecod OSH pefomce o egul bi hould be developed, etblihed d peiodiclly eviewed. The ivetigtio of the oigi d udelyig cue of wok-elted ijuie, ill helth, diee d icidet hould idetify y filue i the OSH mgemet ytem d hould be documeted. Coective ctio eultig fom uch ivetigtio hve to be implemeted to void ecuece. Agemet to coduct peiodic udit hould be etblihed i ode to detemie whethe the OSH mgemet ytem d it elemet e i plce, dequte d effective i potectig the fety d helth of woke d pevetig icidet. Regul mgemet eview hould evlute the ovell ttegy of the OSH mgemet ytem to detemie whethe it meet pled pefomce objective. Agemet hould be etblihed d mitied fo pevettive d coective ctio eultig fom OSH mgemet ytem pefomce moitoig d meuemet, OSH mgemet ytem udit d mgemet eview. Thee gemet hould iclude idetifyig d lyig the oot cue of y ocofomity, well the iititig, plig d implemetig of coective d pevettive ctio i ppopite d timely me. Agemet hould be etblihed d mitied fo the cotiul impovemet of the elevt elemet of the OSH mgemet ytem d the ytem whole. The fety d helth pocee d pefomce of the ogiztio hould be comped with othe ogiztio i the me miig ecto to impove helth d fety pefomce. Behviou-bed fety The phe behviou-bed fety (BBS) efe to the ue of pplied behviou lyi method to chieve impovemet i fety pefomce7. To ctully chieve log-tem cotiuou impovemet, thee method eed to be coupled with igifict employee ivolvemet. Oce it h bee etblihed, the behviou-bed cotiuou impovemet fety poce epeet cloed loop, idicted i Figue 3. The eo to focu o behviou i tht whe icidet occu, behviou i the cucil fil pthwy tht big othe fcto togethe i dvee outcome. Theefoe, ogoig, uptem meuemet of citicl tik behviou povide the mot igifict idicto of wokplce fety7. The t-ik behviou i quetio e the wok pctice of the ogiztio, which e eceily itewove with mgemet ytem, icludig fety ytem. A the fequecy of t-ik behviou eclte, the pobbility tht ijuie will occu icee. Kue7 futhe miti tht the behviou-bed ppoch impove fety ttitude d cultue by idetifyig d the mgig chge i the behviou tht e citicl to fety. 720 NOVEMBER 2005 VOLUME 105 REFEREED PAPER The Joul of The South Afic Ititute of Miig d Metllugy

3 Reducig ccidet i the miig iduty itegted ppoch Figue 3 The behviou-bed fety poce Attitude e fomed by peceptio, the poce by which people elect, ogize, itepet, eceive d epod to ifomtio fom the wold oud them. Fomlly defied8, ttitude i pedipoitio to epod i poitive o egtive wy to omeoe o omethig i oe eviomet. Attitude focu o pecific people o object. A ttitude eult i iteded behviou; thi itetio my o my ot be cied out i give cicumtce. Figue 4 illutte ttitude ccompied by peceptio d behviou. Mot people tully egite the equece of ttitude chge followed by chge i behviou, but Lud d Ao9 put fowd moe compeheive model idictig tht behviou chge lo cue chge i ttitude (ee Figue 5). Becue behvioul ciece povide method fo meuig d mgig the m of behviou, it cut though the idiecte of idividul ctio. Kue7 theefoe gue tht thee i o eed fo detou tht ddee ttitude fit to get to behviou lte. Behvioul om e the vey het of cultue, o chge i behvioul om i cetl to y ucceful cultue chge effot. Kue futhe clim the bic tool of pplied behviou lyi i kow ABC (Atecedet, Behviou d Coequece) lyi. I tem of thi lyi, tecedet i evet tht tigge obevble behviou. A coequece i y evet tht follow fom tht behviou. Although the tecedet i impott, pplied behviou lyi demotte tht coequece e moe poweful detemit of behviou th tecedet. O it ow, the tecedet doe ot diectly detemie the behviou. Ited tecedet elicit ceti behviou becue they igl o pedict coequece. It i the gol of ABC lyi to dicove which tecedet d coequece e ifluecig pticul behviou. Oce thee fcto e kow, they c be chged; d whe the tecedet d coequece chge, behviou chge. I ummy, tecedet d coequece ifluece behviou i diffeet wy. Coequece hve poweful d diect ifluece o behviou, whilt tecedet hve idiect ifluece o behviou, pimily evig to pedict coequece. I dditio to dicoveig tht coequece e toge th tecedet, ome coequece e toge th othe. Thee e thee fetue tht detemie which coequece e toge th othe7: Timig coequece tht follow oo fte ctio ifluece behviou moe effectively th coequece tht occu lte Cetity coequece tht i ceti ifluece behviou moe powefully th upedictble o uceti coequece Sigificce poitive coequece h toge ifluece th egtive coequece. Thee thee ule me tht the coequece, which hve the mot powe to ifluece behviou, e thoe which e imulteouly oo, ceti d poitive. By cott, the weket coequece e the oe tht e lte, uceti d egtive. It i ot the poit of BBS mgemet to chge hum tue, but the to chge the fety cultue i ode to ue the tue of behviou i fvou of fety ited of git it. Thi mout to deviig coequece fo fety tht e oo, ceti d poitive. The iitil oo-ceti-poitive coequece i fvou of fe behviou build ew ttitude towd fety. Thee ew ttitude, i tu, become the ouce of both bode d moe fiely tued ttetio to fety, bigig ew oo-ceti-poitive coequece to be o the fety pefomce of the ogiztio. I thi wy, cotiuou impovemet poce i etblihed, becomig fety mechim. Alogy betwee tditiol SMS d the BBS pocee Bed o the litetue eview of SMS d BBS pocee, SWOT lye hve bee pefomed9 o both pocee to eve bi fom which the imilitie d diffeece betwee the SMS d BBS pocee e highlighted. Tble I d II ummize the SWOT lye10. Cocluio fom the SWOT lyi The litetue eview of the mjo ted i the field of fety mgemet evel tht the tditiol ytem ppoch to occuptiol helth d fety tem fom the ide tht withi compie, juio mge, upevio d woke T c t i o P p e The Joul of The South Afic Ititute of Miig d Metllugy VOLUME 105 REFEREED PAPER NOVEMBER

4 Reducig ccidet i the miig iduty itegted ppoch Figue 4 Behviou impct Figue 5 Model fo ccidet pevetio o the floo tke thei cue fom the top. Reductio i the icidece of occuptiol ijuy d diee i ought by doptig ytemtic ppoch to pevetio, which ivolve the idetifictio of hzd, the plig d moitoig of pevettive meue, d itegtig helth d fety elted citei ito outie wok d deciio t ll level of the ogiztio. Although employee ivolvemet povide the me though which woke develop d expe thei ow commitmet to fety d helth, fety mgemet ytem e ofte too ytem focued, with ot eough egd fo hum fcto. Thi c be coected by itegtig the poitive pect of behvioul-bed fety pocee ito thee tditiol fety mgemet ytem. Coceptul model of itegted fety mgemet ytem It i popoed to itegte the poitive pect of SMS d BBS to fom itegted fety mgemet ytem (ISMS), idicted i Figue 610. The tditiol fety mgemet ytem i eviged to fom the bckboe of the ISMS. The fety mgemet ytem tdd would povide the me fo ogiztio to mge d cotol ik. The poitive pect ocited with BBS will be exploited to develop employee pticiptio itegl compoet of the etie ytem. Lewi11 clim tht pticiptive mgemet i oe wy tht ogiztio c etblih uppotive eviomet. Schutte3 foud tht ubttil pt of the wokfoce peceive tht the wy they e teted impct egtively o thei job ttitude. A commitmet to good copote buie d ocil pctice i theefoe fudmetl to povidig the bi fo the popoed ISMS. The wokfoce i lo le tolet of tditiol hiechicl tuctue. Applyig hd-oed tctic to ubodite become demolizig. Fot-lie upevio coequetly hve get del of ifluece ove fety effot d fety cultue. Lede mut hve the bility to lig, motivte d ecouge employee i wy tht will cete d ehce hmoiou d motivtig wok eviomet, coducive to committed d empoweed wok foce. 722 NOVEMBER 2005 VOLUME 105 REFEREED PAPER The Joul of The South Afic Ititute of Miig d Metllugy

5 Reducig ccidet i the miig iduty itegted ppoch Tble I SWOT lyi of SMS pocee Stegth Diect compy towd complice Stog emphi o tiig, icidet ivetigtio d ik emet Mge key ik d theeby decee the potetil fo icidet d ijuie Povide the poce to mge chge Stog focu o plt d equipmet Wekee Oppotuitie Move towd cotiuou impovemet though implemetig ecommedtio fom ik emet d icidet ivetigtio Collbotio betwee mgemet d woke o egultoy complice iue Cotibute towd ccomplihig cceptble fety cultue Sfety-elted icidet e viewed oppotuity to idetify ytem filue d theefoe impove the ytem Idequte employee pticiptio big bout little, if y, fotlie owehip Alwy t ik of becomig mee ppe execie Too ytem focued with ot eough egd fo hum fcto A ifeio SMS c hve detuctive ifluece o ogiztio Ove-elit o tiig fety cultue, fo exmple whe: Meue lggig idicto Icidet lyi cete i of mitut d fult-fidig - Sfety icetive pogmme dicouge ijuy epotig Accoutbility pocee fil to ecogize idividul fo thei ccomplihmet The bece of ijuie led my mge to coclude eoeouly tht people e wokig fely Thet T c t i o P p e Tble II SWOT lyi of BBS pocee Stegth Povide focu o helth d fety Ehce itel gol chievemet Povide the oppotuity fo high level of employee ivolvemet Povide employee with cle udetdig of fe/ufe behviou Ucove bie to fe behviou Pee peue ct towd, the th git fety (d i elly pee uppot) Utilize the bic mgemet piciple of meuemet to elize impovemet. Wekee Oppotuitie Cete et of fety ule tht e ccepted though ivolvemet Chge the woke poo peceptio of fety Set cotiuou impovemet i motio Get moe employee ctively ivolved. Thet Behvioul item tht e ucceptble to the wokfoce e likely to Mot uio e likely to eet effot fom mgemet to be eeted d igoed commuicte diectly with the employee Lw of mplig could be diegded duig the dt collectio poce. The cuet low level of eductio of employee my pevet the Cptuig of dt ofte poblemtic mjoity of woke fom becomig obeve Scheme ted to focu o type of ik tht e eily obevble d epetitive. Supevio my fil to uppot the poce ice the iitil chge Qulity of feedbck deped o commitmet of upevio itelf i diuptive to thei miio Chllegig to implemet without mkig ue of coultt. Sytem tht Supevio my eet the tk of obeve uwted deped o extel uppot time d gi fil oce the coultt withdw itefeece The o blme tue of the BBS ppoch doe ot del with the poblem of If mgemet doe ot ewd obeve fo collectig dt, they cotiul offede who eit pee peue will top tkig obevtio If mgemet doe ot ppecite good uggetio d ide, obeve will oo tie of offeig them. Occuptiol fety d helth mgemet i the miig iduty Alyi of ftl ccidet i the miig iduty The mi objective of thi pt of the ivetigtio w to idetify the bic d idiect cue of ftl ccidet i miig i ode to detemie whee cuet fety mgemet ytem fll hot. A ue-fiedly ytemtic ivetigtio techique hd bee developed to look beyod the eo d violtio of idividul by me of exmiig the cotibutig fcto ledig to thee occuece12. The im w to idetify locl fcto d filue withi the bode ogiztio d poductive ytem, e.g. tiig, commuictio, opetig pocedue, icomptible gol, ogiztiol cultue, equipmet, etc., tht cotibuted to the icidet. The lyi i boud to icidece i the Rutebug e of the Noth-Wet Regio fo 2003, obtied fom the tiol Deptmet of Miel d Eegy. Ifomtio bout the ge of the deceed, thei wok expeiece, the time of the ccidet, well the depth below ufce w obtied fom the Deptmet of Miel d Eegy. A epeettive pecetge of thee ccidet (69%) w futhe lyed by goig though the officil equiie ito the ccidet. Fll of goud o cve-i wee foud to be the highet cue of ftlitie, followed by tmmig, exploive d mchiey. The mjoity of ccidet occued duig the The Joul of The South Afic Ititute of Miig d Metllugy VOLUME 105 REFEREED PAPER NOVEMBER

6 Reducig ccidet i the miig iduty itegted ppoch Popeou Buie Supeviio, Mgemet d Ledehip Sfety Mgemet Sytem Stdd Employee Pticiptio Soud Copote Buie d Socil Pctice Figue 6 Popoed itegted fety mgemet ytem (ISMS) moig hift whe ely exmitio tke plce d wokig plce e beig mde fe. A ditubig fct i tht 33% of the ftlly ijued wee i upevioy poitio, idictig poible idequte fety wee. The vege wok expeiece of the ftlitie w detemied to be ppoximtely 6 ye. The let expeieced employee e how to be t highet ik. Thi ot oly cete chllege to expdig mie, but lo whee mediclly icpcitted employee hve to be ubtituted, e.g. though the HIV pdemic, which will excebte thi poblem. Attetio i lo dw to the icee i ik employee become moe complcet oce they hve bee doig the job fo exteded peiod, i.e. fo moe th 10 ye (ee Figue 7). The oot cue of the ftl ccidet wee detemied ccodig to the ctegoie, which e coideed i the pltium miig iduty: Complice (64%) Complice d ytem (12%), i.e. pect tht e ctegoized eithe complice iue, o ytem iue Stdd (6%) Sytem (18%), which iclude pocedue. Complice iue epeeted bout 70% of ll the ftl ccidet. Sytem filue cotibuted to 24% of the ftl ccidet. Stdd eem to be bette i hd. Although ytem filue eem to cotibute much le to ftl ccidet th complice iue, it would be pudet to ivetigte fety mgemet ytem i moe detil. The fety mgemet ytem of pecific pltium mie w ubequetly udited d the eult lyed ce tudy. Alyi of the pltium mie fety mgemet ytem The cuet SMS of the ce tudy mie w evluted git the popoed foml ISMS13. A itel tem ude the guidce of extel led udito coducted the udit. Thee i bolutely cle policy tht pomote fety d helth. It w obviou tht compeheive hzd eview poce exit d tht hzd cotol e i plce. Although oppotuitie e povided fo ll employee to ifluece the fety d helth pogmme opetio, oly few pticipte d moe employee ivolvemet ought to be ecouged. A highe level of viible mgemet ivolvemet i equied to demotte commitmet. Membe of mgemet t ll level hould dde the fety behviou of othe by cochig d coectig poo behviou. The eifocemet of good behviou theefoe eed to be give moe ttetio. A fety d helth tiig pogmme fo mgemet doe ot exit. Recommedtio fo ucceful implemettio of the ISMS t the pltium mie Etblihig cultue fvouble towd fe behviou i poible if the ledehip withi the ogiztio i peped to embk o poce to chge the exitig ogiztiol cultue. Thi chge poce h to be popely mged, becue it i ofte extemely difficult fo mge to give up uthoity d fo employee to tlte tht uede of powe ito ltig impovemet i qulity d poductivity. At-ik behviou, the fil pthwy to ccidet d ijuie, e obevble, meuble d mgeble evet. Fll of goud, tmmig, exploive d mchiey wee idetified the mot igifict ik i pltium miig. At-ik behviou ocited with thee key ik hould be moitoed to povide ledig idicto of wokplce fety. I dditio, et of ule hould be ceted to del with ech of thee hzd. The mie mut ctively puue the idetifictio d emovl of bie to fe behviou. A tted elie, ytem behviou e dive by coequece. Whe wokfoce outiely egge i t-ik behviou, oe c be ceti tht the behviou i beig eifoced by tully occuig coequece tht uppot tht behviou. Thoe coequece epeet bie to fe behviou, which geelly fll ito oe of the followig eight ctegoie: Hzd ecogitio Digeemet o fe pctice 724 NOVEMBER 2005 VOLUME 105 REFEREED PAPER The Joul of The South Afic Ititute of Miig d Metllugy

7 Reducig ccidet i the miig iduty itegted ppoch Numbe of employee <2 Ye 2 d <4 Ye 4 d <6 Ye 6 d <8 Ye Wok expeiece Figue 7 Ted i the wok expeiece of ftlly ijued employee 8 d <10 Ye <10 Ye T c t i o P p e Peol choice Peol fcto Cultul bie Ieffective buie ytem Ippopite ewd Egoomic bie. The exitig SMS of the mie i emi-foml ytem tht evolved ove the ye. Implemetig the ISMS peet the mie with ll the dvtge of foml SMS. I dditio, it offe ttig poit fom which to fote gete employee pticiptio. Ltly, it give the eio mgemet tem the oppotuity to embce the mot ppopite ledehip tyle to poitio the mie potetil lede i the field of fety mgemet i the pltium iduty. Cocluio To etblih fety wokfoce lifetyle d key pioity cete mjo d excitig chllege to the miig iduty. Thee i tog evidece tht ogiztiol cultue i mjo pecoditio foteig fe behviou. Employee e moe likely to go beyod thei job deciptio if they e tified with thei job, peceive tht thei upevio e uppotive d coidete, d believe tht they e teted fily by the ogiztio. Effective lede c ipie thei people, d mke eveybody feel poud to be pt of the ogiztio. Cetig uch climte ivolve multifceted mgemet chllege d excellece co bod ge of kill, d ophiticted ogiztiol uppot i equied to mge the poce effectively. At-ik tk elted behviou e the fil commo pthwy fo lmot ll icidet. Sfe behviou loe, howeve, i ot eough. Foml mgemet ytem povide the me fo ogiztio to mge d cotol ik. The bet ik mgemet ttegy i oe tht pemetly elimite the hzd the th elyig o woke ctio to educe the ik. A ik mgemet ttegy become moe depedet o pocedue, wig d PPE, it elibility i geelly coideed to be lowe. A thi occu, employee behviou become iceigly impott compoet of the fety ytem. Filly, lthough the potetil vlue of popoed itegted fety mgemet ytem (ISMS) i decibed i the cotext of oe pltium mie ce tudy to dde thee cocluio, the tue log-tem vlue of uch ISMS mut be demotted d veified i the miig ecto t lge. Refeece 1. DEPARTMENT OF MINERALS AND ENERGY (DME). Aul Repot 2002/ DEPARTMENT OF MINERALS AND ENERGY (DME). Regultio ude the Mie Helth d Sfety Act, 1996 (Act 29 of 1996). Regultio umbe 786, Govemet Gzette, No SCHUTTE, P. A ucce fcto model to etblih d mge hmoiou d motivtig wok eviomet, coductive to committed d empoweed wok foce, utied helth, fety d cofomce. SIMRAC Poject N GEN 511, INTERNATIONAL LABOUR ORGANISATION (ILO). Guidelie o occuptiol fety d helth mgemet ytem. ILO-OSH 2001, Geev, Itetiol Lbou Office, HERMANUS, M.A. Ted i occuptiol helth d fety policy d egultio iue d chllege fo South Afic. Tkemi Pogm i Itetiol Helth, Hvd School Public Helth, pp LONMIN PLATINUM. SHEC Rik Aemet d Mgemet KRAUSE, T.R. The Behviou-Bed Sfety Poce. Secod Editio, New Yok, Joh Wiley & So, SCHERMERHORN, J.R., HUNT, JG., d OSBORN, R.N. Ogiztiol Behvio. Seveth Editio, New Yok, Joh Wiley & So, pp LUND, J. d AARO, L.E. Accidet pevetio. Peettio of model plcig emphi o hum, tuctul d cultul fcto. Sfety Sciece, vol. 42, pp JANSEN, J.C. Reducig ccidet i the miig iduty A itegted ppoch. Deptmet of Egieeig d Techology Mgemet, Uiveity of Petoi, pp LEWIS, P.S., GOODMAN, S.H., d FANDT, P.M. Mgemet: Chllege i the 21t cetuy. Thid Editio, Ohio, South-Wete College Publihig, JANSEN, J.C. Reducig ccidet i the miig iduty A itegted ppoch. Deptmet of Egieeig d Techology Mgemet, Uiveity of Petoi, pp JANSEN, J.C. Reducig ccidet i the miig iduty A itegted ppoch. Deptmet of Egieeig d Techology Mgemet, Uiveity of Petoi, pp u The Joul of The South Afic Ititute of Miig d Metllugy VOLUME 105 REFEREED PAPER NOVEMBER

8 726 NOVEMBER 2005 VOLUME 105 REFEREED PAPER The Joul of The South Afic Ititute of Miig d Metllugy