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Over the last 15 years working in the mining, construction and extractive industries, one of the areas that has always concerned and at the same time drawn the author to it is the application of drilling and blasting in the underground development mining and civil construction tunnelling fields. In that time, the author has come across many drives and tunnels that are larger than design or badly damaged in the perimeter or both. When the question is asked as to why this is the case, the reply is generally æthatÆs the way it is and always has beenÆ. Sometimes it is blamed on bad ground, bad drilling, bad explosives, bad initiation or just plain bad. Most operators build a dilution factor into development and tunneling costs as an acceptance of overbreak and similarly pattern bolt everything to overcome excessive perimeter damage. This paper will attempt to unravel some of the mysteries behind perimeter drilling and blasting in underground drives and tunnels and discuss methods to reduce overbreak and therefore reduce costly dilution and to minimise perimeter damage which in turn will allow more cost-effective ground support. It should not be assumed that better drilling and blasting alone would automatically allow an operation to reduce ground support. The operator must still æreadÆ the ground and its characteristics in order to ensure sufficient ground support is placed to allow the operation to progress safely. This paper will not go into the intricacies of bolting, meshing, shotcreting, concreting and other ground support, but it will use indicative costs for the primary areas of drilling, explosives, excavation and labor to show the magnitude of cost-efficiencies which can be obtained through improved drilling and blasting applications. Drill and blast remains the most flexible and cost-effective method of underground excavation as long as it is applied safely and effectively.

Jan 1, 1999

By Rudyard Kipling

Through the courtesy of the British Museum of Natural History we have received a copy of an address delivered by Rudyard Kipling at Folkestone, Feb. 15, 1918. We take pleasure in reproducing it in full, because its sentiments are just as appropriate here and now as they ever were. If you will allow me. I will tell you a story. Once upon a time, a. hundred years ago, there was a large and highly organised community in India who lived by assassination and robbery. They Were educated to it from their infancy; they followed it

Jan 9, 1918

By O. Gunaydin

Performance measurements of large-diameter circular saws were conducted on eight different carbonate rocks in marble factories located in some areas of Turkey. Rock samples were collected from these factories for laboratory tests. Uniaxial compressive strength, tensile strength and impact strength were determined in the laboratory. The brittleness of B3 (the ratio of compressive strength minus tensile strength to compressive strength plus tensile strength), the brittleness of B5 (the product of percentage fines in the impact strength test and compressive strength) and the brittleness of B8 (half of the product of compressive strength and tensile strength) were calculated from the test results. Hourly slab productions were correlated with brittleness indexes. It was concluded that sawability of carbonate rocks can best be predicted from the brittleness of B8.

Jan 1, 2004

By D. N. Thompson, R. L. Sayer, K. S. Noah

Economical remediation of acid rock drainage (ARD) at secluded high-altitude western ore mines is difficult given the current treatment technology. Several passive-engineered systems that are based on wetland technology were tested in the laboratory with three western ore mine ARDs (Co, Cu and Fe mines) and with a copper leachate effluent. These systems used well-weathered lodgepole pine sawdust as the sole carbon source and mud from a pond at one of the mine sites as the source of sulfate-reducing bacteria (SRB). Simple one-pass flow-through systems removed 44% to 99% of the vari¬ous heavy metals front the Co and Cu mine ARDs and increased the pH from 3 to 7 after 28 days of SRB acclimation with a five-day residence time. Carbohydrate utilization rates were generally low, except for one 437-day run, which consumed 25%, 30% and 21 % of the cellulose, hemicellulose and lignin, respectively. Initial pH, amounts of toxic heavy metals and the degree of predegradation of the sawdust were found to significantly affect both remediation potential and acclimation time. Engineered SRB systems, alone or in combination with other passive technologies, offer promise for the economical remediation of western US ore mine ARDs.

Jan 1, 2000

By Jason Swartz, Gerardo Gomez, Henry Leighton

San Antonio has experienced sustained growth for decades, putting increased pressure on existing wastewater infrastructure. In June 2013, San Antonio Water System (SAWS) reached a Consent Decree agreement that requires significant improvements to the wastewater system over a 10-year period to reduce Sanitary Sewer Overflows. One of the critical projects was the W-6 Upper Segment Tunnel project to reduce sanitary sewer overflows on an existing sewer main running through Lackland Airforce Base. The replacement project consisted of a new tunnel nearly 29,000 LF of primarily 104" FRP. The project also includes nine shafts and multiple trenchless crossings to make near surface connections to the new works.

Jun 23, 2024

Saxonvale mine is a multi bench open pit coal mine developed to its Stage I capacity of 1.75 Mt/y of run of mine coal. Detailed engineering studies for the mine commenced in April 1980, approval to proceed with the development was received in July 1980 and first coal shipments were made in April 1982. The engineering and project management of the mine development was carried out by BHP Engineering. This paper outlines the design and site administration for the development and describes both the organisation structure and the control and administration procedures used by BHP Engineering to ensure that the project was Successful.

Jan 1, 1983

By Juliene Beatriz de Oliveira Ragonesi

O objetivo do trabalho é criar um método capaz de gerar indicadores de inspeção preditiva dos ativos de instrumentação, utilizando dados colhidos de recursos existentes (PIMS – Plant Information Management System) através de técnicas estatísticas. Esses indicadores serão capazes de destacar os ativos prioritários e informar para as áreas os instrumentos que necessitam de intervenções, evitando parada de ativos críticos em corretivas. O conceito de ativo crítico para o projeto é de um instrumento cuja falha paralisa a produção.

Aug 17, 2017

By Patrick Edward Connell

The next generation of the well-established 3-roll Reducing & Sizing Block (RSB), the RSB SCS® is the latest milestone in reducing and sizing technology for SBQ products. It offers enhanced bar quality, improved productivity, mill availability and economy as well as a simplified, safe and environmentally friendly operation. A newly developed modular drive concept of the RSB SCS® grants a smaller footprint in the layout, a reduced oil-lubrication volume and a simplified maintenance schedule. Intelligent engineering leads furthermore to reduced hydraulic functions of the RSB SCS®, which ensures a safe and environmentally friendly rolling. Another integral part of the RSB SCS® is an innovative stand changing concept, which allows automatic stand changing within three minutes. The new RSB SCS® also includes a Fast Remote Control (FRC) which enables the immediate adjustment of the roll gap against the rolling force (under load) within milliseconds. Size changes along the free-size range can also be made within the traditional billet gaps in less than five seconds. At the core of the future-oriented RSB SCS® is a real-time closed-loop control system called Size Control System (SCS®) acting with 3-roll stands adjustable under load (AUL) and / or the heavy duty stands. These features remarkably further improve the rolled tolerances and their reproducibility, and at the same time simplify the operation by means of an automated optimization of the process parameters for the rolled bars.

Aug 16, 2017

By D Clarke, I Minniakhmetov

This paper describes the application of the SBRE framework to model the Olympic Dam deposit, one of the largest copper and uranium deposits in the world. Geostatistical simulations are the best practice for quantifying uncertainty in the mineral value chain and estimating resources. However, these simulations are currently undertaken on an ad hoc basis in the mining industry due to the high requirements in computing resources and capabilities in advanced geostatistics. The SBRE project provides a standard framework to test, build, and run conditional simulation workflows, which has been applied to the Olympic Dam deposit. Conventional geostatistical methods face challenges when modelling the Olympic Dam deposit, such as non-stationarity, non-linear correlations, and a large number of grid blocks to simulate. To address these challenges, a combination of methods was used, including projection pursuit multivariate transform, trend-residual decorrelation, pluri-Gaussian simulations, and turning-bands simulations. Various tools and applications were used to build the model, including in-house developed applications, Autovariogram software (Varify), and the RMSP python library. All computations were accomplished on the AWS cloud using the EC2-Batch service. The final set of simulations was validated using various methods, such as grade-tonnage curves, histograms, swath plots, and variogram reproductions, as well as validation using historical samples back-testing. The study highlights the importance of an automated, modular, and scalable framework in the development of conditional simulation workflows and describes the learning gained from trials of different combinations of methods and software

May 24, 2023

By J Ashford, Minniakhmetov

Geostatistical simulations are the best practice for uncertainty quantification in non-linear systems. Simulations are currently undertaken on an ad hoc basis in the mining industry due to high requirements in computing environments and advanced geostatistics. In contrast to the estimation process, multivariate simulations can be performed using different methods, tools, and computational environments, similar to data science. For large companies with multiple commodities it is important to have a standard framework to test, build, and run workflows using different methods, applications and computational environments. This work presents an auditable, modular and scalable framework to create geostatistical simulation workflows where the workflow is abstracted from the implementation. Key aspects: automation – workflows should be able to run automatically given updated data (if hands on modelling is not required); auditability – workflows should document key considerations and parameters; modularisation – workflows should permit swapping out components, for example substituting domaining in Leapfrog software with automated domaining using machine learning scripts; scalability – easy, repeatable, portable deployments on diverse infrastructure (for example, experimenting on a laptop, then moving to an on premise cluster or to the Cloud); reproducibility – parameters should be archived to permit re-running and reproduction of workflows in future years; and sensitivity analysis – any component of a workflow should be able to run with multiple scenarios of parameters and data to enable global uncertainty quantification and sensitivity analysis. The presented framework can be used to create different workflows for geostatistical simulations in multiple assets to quantify uncertainty in the value chain for resource categorisation, reserves uncertainty, value of information and robust mine planning amongst others.

Mar 22, 2022

By Ashley Woodward, S. Katharine Hammond, Mayela Padilla-Salas

This paper presents a scalable framework for worker safety assessments. The paper focuses on uranium mine reclamation in underserved communities, specifically Cove Chapter of the Navajo Nation. By integrating field observations, OSHA data analysis, systems mapping, and a hierarchical occupational health pyramid, this framework identifies site-specific hazards while addressing broader socio-cultural dynamics. The approach improves upon existing safety programs by suggesting actionable, locally sensitive solutions that prioritize higher-order controls such as hazard engineering interventions and administrative controls. This study contributes to enhanced worker safety, efficient environmental restoration, and engagement in marginalized communities with abandoned mine lands.

Feb 22, 2026

By W. R. Finney

THE formation of scale in boilers and other industrial equipment, and the corrosion of such equipment, are closely related problems. Since in the petroleum industry these problems cover a very broad field, this paper has been confined to the effects of scale and corrosion on gas engines, compressors, pipes and fittings, used in plants extracting gasoline from natural gas, and the steps taken in arriving at a workable plan for combating these evils at the Midwest Refining Co.'s plants in the Salt Creek field, Wyoming. Eliminating, or at least minimizing, the many deleterious effects occasioned by the use of bad water in jackets and cooling systems of gas engines and compressors has been the subject of much study for many years but no generally accepted plan has been evolved. The problem was unusually difficult at Salt Creek, as the severe winters of Wyoming bring operating conditions quite different from those encountered in warmer states, and the water available was especially bad. While the conditioning of water to prevent scale and to lessen corrosion may not be a particularly difficult problem in plants in large industrial centers, it becomes much more difficult when attempted at plants remote from railroads and by men without previous experience to guide them. In fact this difficulty has been so great in the Wyoming oil fields that until comparatively recently it has been the practice to allow much equipment to be ruined rather than to attempt corrective measures. At the Midwest plants this problem was given attention first by the plant men and later by both plant men and laboratory staff. To the latter it was simply one of many problems which arise in connection with field and plant operations, which must be studied and, if possible, solved. Many mistakes were made during the course of this investigation, but since mistakes, properly interpreted, are of value in guiding one's steps aright, it is believed that a review of the different stages of development which have led up to the present method of handling this problem will prove of interest to the industry.

Jan 12, 1926

By Brian K. Failon

Scale formation is a problem that affects many mineral processing systems because the processes require the use of large volumes of water. Scale composition may vary from circuit to circuit, but the scale deposition mechanisms and needs for prevention are often somewhat similar. Likewise, there is a degree of commonality in the prediction, detection, and elimination of scaling conditions in various water systems. This paper briefly reviews some of the conditions which lead to scale formation, as well as some of the common problems associated with unchecked scale growth. The primary focus of the paper is on the variety of chemical scale inhibitors available for use in mineral processing circuits, and the actions of each type. The means of predicting and detecting scaling tendencies are also addressed, and include both direct and indirect methods, i-e., stability index determination and chemical analysis of deposits.

Jan 1, 1986

By N. Fardin, O. Stephansson, L. Jing

A pair of silicon rubber replicas of size 250 mm by 250 mm, from a natural rock joint, was used to produce several high strength concrete fracture replicas of different sizes, from 50 mm by 50 mm to 200 mm by 200 mm. The morphology of the concrete fracture replicas were digitized at the laboratory using a 3D-laser-scanning machine with high accuracy and resolution. The scale dependency of the geometrical properties, including surface roughness and aperture, of the samples were investigated using fractal method. The investigation was extended to study the scale effect on the mechanical properties of the concrete fracture replicas. Four concrete replicas having same geometry from each sampling size were sheared under four different normal loads. The results show that normal and shear stiffness and peak shear strength decrease with increasing sample size and decreasing normal stress. It is concluded that for accurate determination of geometrical and mechanical properties of rock joints in the laboratory and field scales, samples with size equal to or larger than stationarity limit are required. Silikongummiabdrücke der Größe 250 mm x 250 mm einer natürlichen Kluft dienten als Vorlage für mehrere Hochfestbeton Rissreplikas verschiedener Größe. Die Morphologie der Beton Rissreplikas wurde mittels eines 3D-Laserscanners hoher Genauigkeit und Auflösung im Labor digitalisiert. Die Skalenabhängigkeit der geometrischen Eigenschaften, dies inklusive Oberflächenrauhigkeit und Öffnungsweite, wurden mittels Fraktalen bestimmt. Die Studie wurde durch die Untersuchung der mechanischen Eigenschaften der Betonrepliken erweitert. Hierbei wurden vier Betonrepliken der selben Geometrie jeder Probengrösse unter vier verschiedenen normalen Belastungen abgeschert. Die Ergebnisse zeigen das sowohl Normal- und Schersteifigkeit als auch die Spitzenscherfestigkeit mit zunehmender Probengrösse und abnehmender Normalspannung abnehmen. Es hat sich gezeigt, daß für eine genaue Bestimmung der geometrischen und mechanischen Eigenschaften von Felsklüften im Labor und im Feld Proben einer Größe gleich oder größer des stationären Limits verlangt werden. Deux répliques en gomme de silicone d’une fracture naturelle, de dimension 250 mm par 250 mm, ont été utilisées pour produire des répliques en béton de haute résistance de dimensions allant de 50 mm par 50 mm à 200 mm par 200 mm. La morphologie de ces répliques a été digitalisée au laboratoire à l’aide d’un laser-scanner 3D haute résolution et haute précision. L’influence de l’échelle des propriétés géométriques, incluant rugosité et ouverture, a été étudiée en utilisant la méthode des fractales. Des essais complémentaires ont été réalisés afin d’étudier l’effet d’échelle sur les propriétés mécaniques des répliques de fracture en béton. Quatre répliques béton de même géométrie pour les différentes tailles d’échantillons ont été cisaillées sous quatre valeurs de contrainte normale. Les résultats montrent que la rigidité normale et tangentielle ainsi que la résistance de pic diminuent en proportion de l’augmentation de la taille de l’échantillon et de la diminution des contraintes normales. On peut en conclure que, pour une détermination précise des propriétés géométriques et mécaniques des fractures au laboratoire et sur le terrain, des échantillons de taille égale ou supérieure à la limite stationnaire sont nécessaires.

Jan 1, 2003

By N. Shi, T. G. Joseph

ABSTRACT: A prototype test dipper (at 1/20th volume and a geometric operating scale of 2.85) was compared during field trials against a conventional dipper with the same tare weight using the same test shovel. Both dippers followed similar dig trajectories, invoked by the shovel operator. A Microsoft® Visual Basic-embedded spreadsheet was used to interpret qualitative visual and quantitative numerical loading data collected on the hoist and crowd dig response. Overall the concept dipper, even with a 50% greater capacity, provided indications of a smoother dig cycle with lower peak hoist loading events and a lower energy per unit excavated.

Jan 1, 2011

By Michael N. Allenby

One of the least discussed areas in the ever-improving technologies of gold recovery from ore bodies and tailings is the chemistry of the waters used in the plants. Carbon-in­ pulp, carbon-in-leach, heap/dump leaching and iological oxidation processes are all affected by water quality. The remoteness of a lot of the plants means that the large water requirements can often only be met by a ground water source. The chemistry of waters from different sources poses different problems, but generally a lot of these waters are scale forming. Scale-forming tendencies can be described by calcium, magnesium, barium and strontium assays. They can be notated by Langelier and Ryznar indices. They can be plotted by computer programmes that print out scaling indices at different conditions. The propensity to scale can -be readily determined. The prevention of scaling -or at worst minimisation of scaling -is the ambition of the suppliers of scale inhibition programmes. This prevention/minimisation technology is discussed below.

Jan 1, 1993

By C. Michael Dickinson

In support of the DNA Deep Basing Program, SRI International has been performing scale model experiments on protective structures since 1973. The SRI program includes field and laboratory tests of mini- structure models with surrounding natural or simulated geology. This paper contains a synopsis of some of the results of this research.

Jan 1, 1984

By Smith S. F, Terezopoulos N. G

This paper discusses experimental results of physical scale models employed to study the stability of a pillar between rectangular roadways. A programme of laboratory investigations utilising a bi-axial test rig has been undertaken to examine the influence of various stressfields on the stability of pillars between mine roadways. The effect of pillar height/width ratio on the overall stability is studied. Observations of failure characteristics in and around pillars are discussed especially in relation to the various stressfields applied to the models.

Jan 1, 1992

By K. Goshtasbi Goharizi

This paper discusses experimental results of physical scale models employed to study the stability of a pillar between rectangular roadways. A programme of laboratory investigations utilising a bi-axial test rig has been undertaken to examine the influence of various stressfields on the stability of pillars between mine roadways. The effect of pillar height/width ratio on the overall stability is studied. Observations of failure characteristics in and around pillars are discussed especially in relation to the various stressfields applied to the models.

Jan 1, 1992

By Dennis V. Woods, J. Duncan Crone

"In order to determine its capabilities and to aid in the interpretation of fie ld results, a scale model study and field tests were carried out on the Crone borehole pulse electromagnetic (PEM) system. The model results indicate that if a borehole passes in the vicinity of a tabular conductive body, the system will not only detect the presence of the body, but will also return information as to its conductivity-thickness product, size, altitude and position.The effect of variation of these electromagnetic and geometric factors on the shape of the response curve from a borehole PEM survey is displayed by a number of suites of scale-model response curves. These model curves can be used directly as type curves in the interpretation of field results. Field tests of a prototype PEM system provide a check on the scale-model results and also summarize the procedure of interpreting field data using the model type curves.The borehole pulse EM system can be effectively used as a follow-up geophysical instrument for locating and delineating known conductive bodies. It can also be profitably utilized as a primary geophysical exploration tool in areas of deep mineralization below the depth limit of conventional airborne and ground geophysical systems. The probed area of a diamond drill hole in these cases is increased from a 1- inch drill core to a zone extending hundreds of feet from the hole."

Jan 1, 1980