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The current paste backfill system at the Gwalia gold mine in Western Australia has been in operation since 2009 and involves blending harvested mine tailings with water and a binder consisting of a mixture of cement and blast furnace slag and discharging into a gravity-driven reticulation system. The backfill plant operates at about 130 m3/h of paste fill to a depth of about 1 500 m below surface. Backfill is conveyed underground through a borehole, and in 2011 a second backup borehole was installed. The first borehole suffered a blockage in in October 2013 which was cleared by flushing with water and air but the hole immediately became blocked again. The second borehole was then put into operation and a third borehole installed, with the first borehole being abandoned. A complete review of the system was undertaken, and a life of mine review was also conducted to consider the requirements and implications of extending the reticulation system to 1 800 m below surface. The reasons for the high wear in the first borehole were investigated, and a number of changes proposed, including increasing the flow rate of the paste fill to ensure full flow conditions in the borehole pipe, increasing the concentration of the paste fill and reducing the pipe diameter of the reticulation system when extending it to deeper levels. It is proposed to install a reduced pipe diameter for future extensions. Recommendations are made for backfill system management, including tracking the reasons for downtime by area, designating a backfill coordinator, effective use of instrumentation and development of a wear monitoring programme and database., The current paste backfill system at the Gwalia gold mine in Western Australia has been in operation since 2009 and involves blending harvested mine tailings with water and a binder consisting of a mixture of cement and blast furnace slag and discharging into a gravity-driven reticulation system. The backfill plant operates at about 130 m3/h of paste fill to a depth of about 1 500 m below surface. Backfill is conveyed underground through a borehole, and in 2011 a second backup borehole was installed. The first borehole suffered a blockage in in October 2013 which was cleared by flushing with water and air but the hole immediately became blocked again. The second borehole was then put into operation and a third borehole installed, with the first borehole being abandoned. A complete review of the system was undertaken, and a life of mine review was also conducted to consider the requirements and implications of extending the reticulation system to 1 800 m below surface. The reasons for the high wear in the first borehole were investigated, and a number of changes proposed, including increasing the flow rate of the paste fill to ensure full flow conditions in the borehole pipe, increasing the concentration of the paste fill and reducing the pipe diameter of the reticulation system when extending it to deeper levels. It is proposed to install a reduced pipe diameter for future extensions. Recommendations are made for backfill system management, including tracking the reasons for downtime by area, designating a backfill coordinator, effective use of instrumentation and development of a wear monitoring programme and database.

English:Background: Historically characterized by a high prevalence of alcohol addiction and dependency, South Africa has in recent years experienced an unprecedented increase in illicit drug use, linked to organized criminal activities. While internationally, the role of pharmacotherapy in the multi-disciplinary treatment of addiction/dependency becomes more important based on an increasing body of evidence revealing the biological nature of the condition, major transformation in the Health and Social delivery systems are taking place locally. Aim: The study aims to provide a critical analysis of current treatment practices regarding pharmacotherapy for drug addiction/dependency in the Free State against the background of the biological processes involved in the addiction/dependency state as well as aspects of health service delivery that may influence the use of pharmacotherapy. The analysis forms the basis for the development of a framework for the treatment of substance addiction and dependence regarding pharmacotherapy, taking into account the findings of the literature study and local context. Material and Methods: Both quantitative and qualitative methods were used. A questionnaire and structured interview were conducted with 121 health care professionals that could reasonably be expected to be confronted by patients with addiction and dependency. The population included a randomized sample of general practitioners selected from regional, district and basic environments in the Free State; purposely selected representatives of state hospitals and private treatment centres, as well as private psychiatrists and therapists in the corresponding towns. Results: Help-seeking for addiction occurs in a distinguishable pattern across the various professional groups. Private general medical practitioners are an important conduit into treatment for alcohol addiction and dependency. Depending on the local organization of services, they are also actively involved in the me, Afrikaans: Agtergrond: Histories gekenmerk deur „n hoë voorkoms van alkoholverslawing en afhanklikheid, het Suid-Afrika oor die afgelope aantal jare „n ongekende toename in onwettigemiddelgebruik beleef, gekoppel aan georganiseerdemisdaadaktiwiteite. Terwyl die rol van farmakoterapie in die multidissiplinêre behandeling van verslawing/afhanklikheid internasionaal toeneem weens die groeiende bewyslas van die biologiese aard van die toestand, is daar major transformasie van Gesondheidsorg- en Maatskaplikediensleweringsisteme plaaslik. Doel: Die studie het „n kritiese analise van huidige behandelingspraktyke aangaande farmakoterapie vir alkohol- en dwelmverslawing en afhanklikheid in die Vrystaat ten doel. Die analise geskied teen die agtergrond van die biologiese prosesse betrokke by die toestand van verslawing sowel as die aspekte van gesondheidsorg dienslewering wat die gebruik van farmakoterapie beïnvloed. Die analise vorm die basis vir die ontwikkeling van „n raamwerk vir die behandeling van substans verslawing en afhanklikheid betreffende farmakoterapie, met die inagneming van die bevindinge uit die literatuur en lokale konteks. Materiaal en Metodes: Beide kwantitatiewe en kwalitatiewe metodes is gebruik. „n Vraelys is voltooi en „n gestruktureerde onderhoud is gevoer met 121 professionele gesondheidsorgwerkers wat redelikerwys verwag kan word om gekonfronteer te word met verslawing en afhanklikheid. Die populasie bestaan uit „n lukraak geselekteerde monster van algemene praktisyns uit streeks-, distriks- en basiese omgewings in die Vrystaat; doelmatig geselekteerde verteenwoordigers van staatshospitale en private behandelingsentra, en private psigiaters en terapeute in ooreenstemmende dorpe. Resultate: Hulpsoeking vir verslawing kom voor in „n waarneembare patroon oor die onderskeie professionele groepe. Private algemene mediese praktisyns vorm „n belangrike toegangspunt vir behandeling vir alkohol verslawing en afhanklikheid. Afhangend van die lokale organisasi