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By Kym L. Morton

Ground water and associated pore pressure represent elements which can have a negative impact on surface mining and slope stability. Ground water flow and deformation within a slope influence each other. An increase in pore pressure will result in a decrease of effective stress; and conversely if the pore pressure decreases, the effective stress increases. Slope analysis and slope design calculations require good information on pore pressure distribution around an open pit excavation. Until recently very little pore pressure data was available and assumptions had to be used. Location and design of measuring points depend on geological and structural setting, geotechnical domains and practicality. Good planning and the use of sensitive point piezometers to measure in situ pore pressures means that real-time data can be collected and used for the construction of flow nets, the determination of pore pressure distribution around an open pit mine, the validation of the dewatering/depressurization requirements, the calculation of the efficiency of the dewatering system and finally the use of pore pressure data in slope stability analysis. The recommended layout for a monitoring system, types and design of piezometers, data collection and use of the pore pressure data are presented.

Jan 1, 2008

By J H. Sullivan

Contents Background information Locality of Kumba?s Iron Ore Mines Sishen?s Product Specifications Geological Description of boreholes Sample Preperation Block delineations Production Geology Process Laboratory information Turnover times reached Inter Laboratory Comparisons Quality control activities in lab Purpose of laboratory Results attained Standard samples Monitoring of processes with QA/QC standards Mean paired difference of duplicates Duplicate samples Conclusion

Jan 1, 2005

By D. P. Power

The development of an accounting code for the metallurgical industry has been debated for many years. Following the series of tumultuous economic events in the nineties and earlier this century that have affected business, there was much need for legislation to be passed to minimize potential risk. One of the consequences to affect the mining industry was the enhancement of existing geological codes for reporting. In parallel the sponsors of AMIRA have taken the brave step to develop a generic code for metal accounting that embraces the full gamut of industry. In this paper the code will be reviewed in the context of metallurgical accounting as it applies to coal preparation. This paper provides the background for this development and an insight into the mechanism for the debate for the generation of this code. The key elements of the code as it applies to the coal industry are explained but most importantly the key opportunities are highlighted.

Jan 1, 2010

By R. Ajalloian, L. Karimzadeh

This paper describes the engineering properties of Givi dam foundation. Givi dam will be built across the Givi River on the andesitic rocks (Karaj formation) in Ardabil province (northeast of Iran). Geotechnical investigations including drilling, pumping tests, sampling for laboratory testing and discontinuity survey. Physical and mechanical properties of andesitic rocks such as density, water absorption, porosity, uniaxial compressive strength, triaxial compressive strength, durability and direct shear tests are evaluated in this paper. Discontinuity data are process for the determination of dominant sets and for the rock mass characterization in terms of classification systems ( RMR, Q and RSR ). Correlations between these three classifications are discussed. Le barrage doit être construit sur la rivi_re givi qui cou_e sur les andesites (formation de Karaj)dans la province d_ Ardebile situee_ a Nord- Ouest de l_ _Iran. Les études géophsique commesondage, Pompage. Et échantillonnage afin de verifier les discontinutés out éte_ effectuées. Lesproprietés physique et méchanique des roches andesifique ont éte_ verifieés. Les informations concernaüt aux discontinuitiés afin de montrer leur principale direction ont éte_ verifieés, les proprietés des roches dans leurs ensemble ont éte_ etudieés. Les divers classifications(RMR,Q,RSR ) ont éte_ comparés et analyseés. Dieses Schreiben ist zur Erklaerung der Ingenieureigenschaften ueber Baugrund des Givi Deiches.Dieser Deich soll im Givi fluss auf Andesitgesteine (Karaj formation) gebaut werden. Der platzdes Deiches legit im Ardebil Provinz nordwestlich von Iran. Geotechnische Untersuchungen Sind:Bohrungen, pumpen Versuche, Probenentnahme fuer Laborversuche, BrechbarkeitBestimmungen, physikalische und mechanische Eigenschaften der Andesitgesteine wurde hierausgewertet, wie Z.B.: Wasserleitfahigkeit, Porositaet, Scherfestigketswiderstand, Informationenueber Brechbarkeiten der Gesteine wurde gesamelt, und die meisten Brechbarkeiten bestimdamitman die Gesteine besser klassifizieren kann. In Endefekt wrid die Resultate verschiedeneKlassifizierung wie RMR, Q, und RSR besser geachtet und zusammen vergliechen.

Jan 1, 2003

By W. Wittke, D. Schröder, H. Polczyk

ABSTRACT: The Urft dam, the Diemel dam and the Eder dam are three old masonry damslocated in Germany. The paper describes the rehabilitation measures and the correspondingstability analyses carried out to adjust the dams to today's standards. Remedial works such as theexcavation of inspection galleries, the installation of a grout curtain with a downstream drainagescreen as well as the installation of pre-stressed permanent tendons were carried out. In all threecases the stability of the upgraded dam could be proven on the basis of finite element analyses. ZUSAMMENFASSUNG: Die Urft-, Diemel- und Edertalsperre sind drei alte deutscheSchwergewichtsmauern aus Bruchsteinmauerwerk. Im Beitrag werden Instandsetzungsmaß-nahmen und Standsicherheitsnachweise beschrieben, die erforderlich waren, um die Staumauernan den heutigen Stand der Technik anzupassen. Hierzu wurden Kontrollgänge aufgefahren,Dichtungsschleier mit luftseitiger Dränage sowie vorgespannte Daueranker hergestellt. In allendrei Fällen konnte unter Berücksichtigung der Instandsetzungsmaßnahmen die Standsicherheit derMauer auf der Grundlage von Berechnungen nach der Methode der finiten Elemente nachgewiesenwerden. RÉSUMÉ: Les barrages de Urft, Diemel et Eder sont trois barrages-poids vieux allemandsconstruit de maçonnerie de moellon. Dans cet article, opérations de remise en état et preuves destabilité sont décrits, qui étaient nécessaires pour adapter les barrages à l'état de la techniqueactuelle. À cet effet, des galeries de contrôle étaient creusés, voiles d'étanchéité avec des drains àla face aval et tirants précontraints permanents étaient fabriqués. Dans tous les trois cas, tenantcompte des opérations de remise en état, la stabilité de la barrage pouvait être prouvée à partir decalculs selon la méthode des éléments finis.

Jan 1, 2003

By A. Mitchell

On 25 August 2011, Andrew Mitchell, Lucas Moalusi, and Matthew van der Want of Bell Dewar hosted a presentation on Mining and Communities in Mooinooi, in the North-West Province. The conference was attended by traditional leaders in the North-West Province, officials from the Department of Local Government and Traditional Affairs, and executives from the mining industry. The presentation concerned traditional governance in mining, communities? rights in terms of applicable legislation, and the corporatization of community affairs.

Jan 1, 2012

A modified germanium recovery process in conventional zinc metallurgy, based on the understanding that ferric hydroxide has strong ability to coprecipitate germanium element, was presented. The relaxed lab-scale experiments were conducted to evaluate its technological feasibility. The experimental results obtained show the new process has great competitive advantage over the conventional one.

Jan 1, 2008

By A. C. Wingrove

The paper outlines the selection of a dewatered tailings backfill system for the Johannesburg Consolidated Investment Gold Division, and covers the following aspects: (i) 16 Shaft pilot testwork; (ii) engineering design problems relating to the Cooke 3 Shaft backfill operation; (iii) in-line mixing - applications with respect to the Randfontein Estates Gold Mine and Western Areas Gold Mine backfill operations; and (iv) pipeline friction losses.

Jan 1, 1988

By W. J. C. Pothas

This paper describes the state of the art in backfilling techniques used on East Driefontein Gold Mine. Areas covered are the preparation plant, the distribution plant, the pipeline network and finally placement techniques. The in-situ performance of placed backfill has been assessed by the Chamber of Mines Research Organization, and results to date will be shared. Details of the backfill expansion programme that will enable this facility to be made available to all working places are included. Benefits obtained by the introduction of backfilling are described, together with certain management aspects to be considered in the control of quality and quantity of support supplied via a pipeline.

Jan 1, 1988

By I. Zemanek, A. Rozsypal

Mrazovka tunnel was excavated under one building whose subsurface space was not possible to reinforce against additional settlements induced by digging. In the presented contribution the risk analysis, warning levels and results of deformation measurements are described. Lespace souterrain d‘un des bâtiments sous lequel le tunnel Mrazovka a été creusé n‘a pu être renforcée contre l‘affaissement supplémentaire provoqué par l‘emplacement du tunnel. Le matériel présenté décrit l‘analyse des risques, le niveau des limites et les résultats des mesures des déformations. Der Untergrund eines der Gebäude, unter dem der Tunnel "Mrazovka" ausgeschachtet wurde, war es nicht möglich, gegen nachträgliches Setzen zu versteifen, hervorgerufen durch die Untertunnelung. Im vorliegenden Beitrag sind Gefahrenanalyse, Grenzwerte und Ergebnisse von Deformationsmessungen beschrieben.

Jan 1, 2003

By D. E. Kraushaar

Ruhrkohle in West Germany evaluates and compares the net present values of long-term periods from its coal mines by a computer assisted long-term planning system. Two main parts of this system are computer programs for the prediction of: (a) mineable reserves and their distribution in longwall panels as a function of dependent geological variables; (b) daily outputs and costs of longwall panels as a function of dependent geo- logical, layout and operational variables. This paper describes the investigations, which ended in the above computer programs: ? the collection of information from past workings and their organization in databases; ? the statistical evaluation of the databases, and ? the resulting correlation formulas. The correlation formulas vary the mean dependent variables as a function of independent variables which can be indicated with high reliability for planning projects in the long run. The system thus serves the purpose of facilitating long-term planning and excluding biased individual judgement of local planning staffs.

Jan 1, 1987

By R. M. G. Machunter

The use of testwork to establish an economically feasible separating plant has been a long established practice in the mineral processing industry. However, uncertainties in orebody characteristics and equipment/plant operation can have a significant impact on the separation performance of a given project. This paper explores the impact of uncertainties derived during testwork at key processing stages on the overall performance of mineral processing flowsheets. Case studies for both mineral sand and iron ore projects will be used to illustrate the concepts studied in this paper.

Jan 1, 2007

By S. Özgen

In this study, the possibility of beneficiation of chromite tailings in the Uckopru/Fethiye-Turkey region by a combination of hydrocyclone and multigravity separator (MGS) was investigated. The two significant operational parameters of hydrocyclone, which were diameter of the apex and diameter of the vortex, and the three significant operational parameters of the MGS, which were drum speed, tilt angle, and wash water, were varied and the results were evaluated with the central composite rotatable design. In order to produce a chromite concentrate by hydrocyclone and MGS, mathematical model equations were derived by computer simulation programming, applying the least-squares method using Minitab 15. Second-order response functions were produced for the grade and recovery of chromite concentrates.

Jan 1, 2012

By S. Özgen

In this study, the possibility of beneficiation of chromite tailings in the Uckopru/Fethiye-Turkey region by a combination of hydrocyclone and multigravity separator (MGS) was investigated. The two significant operational parameters of hydrocyclone, which were diameter of the apex and diameter of the vortex, and the three significant operational parameters of the MGS, which were drum speed, tilt angle, and wash water, were varied and the results were evaluated with the central composite rotatable design. In order to produce a chromite concentrate by hydrocyclone and MGS, mathematical model equations were derived by computer simulation programming, applying the least-squares method using Minitab 15. Second-order response functions were produced for the grade and recovery of chromite concentrates.

Jan 1, 2012

By H. Sasao, Y. Obara, A. Hirata

In the upper part of the planned location of the portal of a highway tunnel, there was a steep rock cliff with several unstable rock blocks. It seemed that the risk of those rock blocks to fall was very high. The cut-out to stabilize the rock cliff was monitored with various measuring instruments to prevent the sudden fall of the rock blocks. This paper discusses the measurement of acoustic emission and interpretation of its result during excavation of the rock cliff. We calculated displacements by integrating the accelerogram twice in terms of time, and demonstrated that slight displacements can be calculated from the measured AEs. Dans la partie supérieure de l’emplacement prévu pour le portail d’un tunnel autoroutier, il y avait un escarpement rocheux raide avec plusieurs blocs rocheux instables. Le risque de chute de ces blocs semblait très élevé. Lors de la coupe pour stabiliser l’escarpement rocheux, le suivi a été effectué avec différents instruments de mesure pour éviter la chute brutale des blocs rocheux. Cette thèse présente les mesures d’émission acoustique (EA) et l’interprétation de leurs résultats pendant l’excavation de l’escarpement rocheux. Nous avons calculé des déplacements en intégrant l’accélérogramme deux fois par rapport au temps, et montré que de petits déplacements sont calculables à partir des EA mesurées. Im oberen Teil des geplanten Ortes des Stollenmundes eines Autobahntunnels gab es einen steilen Felsen mit mehreren instabilen Felsenblöcken. Die Gefahr schien sehr groß zu sein, dass diese Felsenblöcke einstürzen können. Beim Abbau um die Stabilisierung des Felsens wurde das Monitoring mit verschiedenen Messinstrumenten zusammengestellt, um den plötzlichen Verfall der Felsenblöcke zu verhindern. Das vorliegende Papier diskutiert die Akustische Emission und die Auslegung deren Ergebnisse während des Abbaus des Felsens. Wir berechneten die Verschiebungen durch zweimalige Integrierung der Accelerogrammen in Bezug auf die Zeit. Die dargestellten kleinen Verschiebungen können aus den gemessten akustischen Emissionen berechnet werden.

Jan 1, 2003

By J. E. Quintanilha de Menezes, L. Ribeiro e Sousa, I. Ferreira

The Paradela dam has a spillway that makes it possible to discharge a maximum flow of 400 m3/s, the water discharges being on the river Sela, about 2km upstream the river Cávado. After the first use of the spillway, some landslides have occurred on the right bank of the river Sela as a result of the erosion generated on its base about one hundred meters near some houses of a small village. This paper presents a study performed for the slope stability where finite element results are taken into account. A monitoring program was established that essentially consisted of measuring sub-horizontal displacements in points located in boreholes at different depths and also phreatic levels. Some monitoring results are presented. Le barrage de Paradela a une décharge d’eau avec un débit maximal de 400 m3/s sur le fleuve Sela dans un endroit situé environ 2km sur l'amont du fleuve Cávado. Après la première utilisation de cette décharge, quelques glissements se sont vérifiés sur le versant droit du fleuve Sela résultant de l’érosion générée sur sa base dans une zone à 100 mètres de quelques maisons d’un petit village. Ce travail présente une étude réalisée concernant la stabilité du versant avec la considération des résultats des éléments finis. Un programme d’auscultation a été mis en place pour mesurer les déplacements sub-horizontales sur des points situés en forages à des différentes profondeurs. Quelques résultats de cette monitorization sont présentés. Der Ueberlauf des Padela Dammes ermoeglicht das Ablassen einer max. Wassermenge on 400 m3/s in den Sela Fluss, ca. 2 km flussaufwaerts des Cávado Flusses. Nach Inbetriebnahme des Ueberlaufes traten in ca. hundert Meter Entfernung zur Wohnbebauung eine Dorfes Erdrutschungen am rechten Ufer des Sela Flusses auf, die auf Erosionen am Flussbett zurückzuführen waren. In der vorliegenden Studie wurde die Boeschungsstabilitaet unter Beruecksichtigung von Berechnungsergebnissen der Finiten Element Methode untersucht. Es wurde ein essprogramm ausgearbeiten, das im Wesentlichen auf Messungen der Untergrundverformungen in verschiedenen Bohrlochteufen sowie auf Grundwassermessungen beruht. Im Folgenden sind einige Messergebnisse dargestellt.

Jan 1, 2003

By R. Tabanrad

This article examines the stability analysis of intake tunnels of Karun III dam & power plant. The tunnels have been excavated with a 3-dimensional and fairly complicated geometry in Pabdeh weak formation rocks at Zagros region. Due to the particular excavation geometry and inapplicability of plane-strain status, the stability of these excavations has been analyzed using both the 3D elastic software Examine 3D and the 2D non-elastic software UDEC simultaneously. The geomechanical parameters have been estimated by back analyzing the measured displacements from instruments, which were installed in the tunnels, and the parameters have been used in non-elastic numerical model. The results of the analysis show that the strains occurred in surrounding rock mass are less than the allowable failure strain and that the tunnels are stable. In addition, considering the results of non-elastic 2D analysis, the areas with unstable potentiality were identified and after the instability occurred at the areas predicted by the model , it was stopped up to the allowable strain limit through installing additional support . Bei diesem Artikel handelt es sich um eine Analyse der Festigkeit der Eingangstunnel des Damms und Elektrizitätswerks “Karoon III”.Die Tunnel haben drei Dimensionen und eine sehr schwierige Form und sind in brüchigen Felsen in “Pabedeh ,in Zagrossgebirge”eingebohrt.Aufgrund besonderer Form der Bohrung wurde ihre Festigkeit durch elastische dreidimensionale Soft-ware analysiert,die gleichzeitig die drei-und zweidimensionale unelastische Soft-ware UDEC benutzt hat.Die geometrische Parameter sind mit Ausnützung der Analyse berechneter eingesetzter Versorgungen,die in Tunnel aufgebaut sind,bewertet.Und diese Parameter sind in Zahlen-Analyse benutzt.Die Ergebnisse dieser Analyse zeigen,dass die Drücke an Felsen weniger als problematischer Grad der Drücke sind und die Tunnel fest sind.Ausserdem wurde mit einem Einblick auf die Ergebnisse der unelastischen zweidimensionale Analyse die eventuellen unfesten Teile bestimmt.Nach entstandener Unfestigkeit an diesen Teilen wurde die problematischeDrücke für Aufbau mehrere Anlagen gestoppt. Cet article examine l'analyse de la stabilité de tunnels de la prise de Karoun barrage III et centrale électrique. Les tunnels ont été excavés avec une 3 dimensionnel et compliqué géométrie dans Pabedeh que la formation faible balance à région Zagros équitablement. Dû à la géométrie de l'excavation particulière et inapplicabilite de statut de tension plane, la stabilité de ces excavations a été analysée en utilisant les deux le 3D logiciel élastique Examen 3D et le 2D logiciel non - élastique UDEC simultanément. Les paramètres du geomechanical ont été estimés en analysant le déplacement mesuré d'instruments qui ont été installés dans les tunnels et les paramètres en arrière a été utilisé dans les modèles numériques non - élastique. Les résultats de l'analyse montrent que les tensions se sont produites dans masse du roc environnante est plus petit que la tension de l'échec admissible et que les tunnels sont stables. De plus, les régions avec potentialité instable ont été identifiées étant donné les résultats de 2D analyse non - élastique, et après que l'instabilité se soit produite aux régions prédites par le modèle, il a été arrêté jusqu'à la limite de la tension admissible à travers installer du support supplémentaire.

Jan 1, 2003

By K. Sinding

This paper discusses reasons for mining company mergers that have become the fashion, the role of the ?Juniors? and asks what the motives might really be. It examines changes in company concentration over the last 20 years in key mineral segments. Data at different stages of a project are examined to attempt to elucidate the role of the ?Juniors?. Areas for further research are suggested.

Jan 1, 2009

By A. J. Barrett

Backfilling at Vaal Reefs during the experimental phase has been carried out using cyclone-separated tailings which are transported underground hydraulically by means of a borehole. The selected tailings are piped from the borehole to the stope and then, after the addition of a flocculant, deposited in place via single or multiple nozzles. The successful performance of the backfill/stope system relies not only on the actual quality of the placed material, but also on the effective operation of stope filling. The success of stope filling relates to the complex, time- dependent interaction of backfill, stope and barricade materials, and the transport and placement procedures used. A comprehensive laboratory testing programme was carried out on backfill materials at Vaal Reefs in conjunction with the experimental stope- filling operation. The range of testing techniques corresponds to the requirements of each stage of the backfilling process. Where necessary, new or alternative techniques were sought during the course of the experiment to satisfy and facilitate better understanding of the different processes. These techniques comprise both routine quality control testing and research-oriented testing. The laboratory testing techniques appropriate to each stage of the backfill process are briefly discussed. This paper presents the main conclusions of the study and identifies areas for further research.

Jan 1, 1988

By A. J. Reynolds

In recent years, rapid depletion of the higher grade reserves, allied to decreases in paylimits, has led to the exploitation of secondary, erratically mineralized placer horizons on various marginal and low grade gold mines. On Blyvooruitzicht Mine, the rich Carbon Leader Reef has limited reserves, necessitating exploration of the lower grade Middelvlei Reef. This placer has always presented evaluation and exploration problems, to such an extent that it was, at one stage, considered uneconomic. Despite an extensive underground drilling programme no ore reserve targets of reasonable size were apparent. However, when a certain degree of parallelism between sedimentological trends in the Middelvlei Reef and the underlying Carbon Leader was recognized, a meaningful exploration model could be developed. Firstly, all historical sampling records for the Carbon Leader were entered into a computerized system; the database comprised in excess of 340 000 data points. Variables captured consisted of gold value, uranium value, con- glomerate thickness and total reef thickness. The raw data were then averaged into blocks, and plots of different variables were computer-generated for further analysis. This enabled the Carbon Leader to be modelled sedimentologically and, thereby, exploration targets for the Middelvlei Reef were generated, based on the Carbon Leader facies trends. Geostatistical analysis of sampling data in exposed areas of the Middelvlei Reef underground has confirmed the sedimentological breakdown of the placer into distinct facies areas. A facies model relating value distribution patterns to depositional trends, both for the Carbon Leader and the Middelvlei Reef, has thus been incorporated into a mine planning strategy.

Jan 1, 1987