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By Greg Ford

Each year, companies spend millions of dollars on safety training and on safe equipment, money that is generally well spent. Despite that, we still make mistakes. What happens if the mistakes are made not because of inadequate training, but because we are hard-wired to act in a certain way? If you read any of the ?Because of Human Error? text boxes in this document, situations like these may look familiar in your own workplace. ?The issues of risk, health, safety and the environment are getting more attention now than ever before, at all levels of the organization,? said Calvin Price, vice president of Global Health and Safety at LNC-Lavalin Inc., a company with 21,000 workers worldwide. Most would agree with Price that attention to safety is increasing because responsible companies care about their workers and the workers? colleagues, families and communities. However, cynics might say that the safety spotlight is powered by the corporate bottom line. Direct costs created by workplace injuries total $51.8 billion annually and include workers? compensation payments, medical expenses, civil liability damages and litigation expenses. This sum represents a staggering one quarter of each dollar of pretax corporate profits. Indirect costs may run as much as 20 times the direct costs of on-the-job accidents and illnesses. Examples of indirect costs include training replacement employees, investigating the accident and implementing corrective measures, lost productivity, repairing damaged equipment and property, and costs associated with lower employee morale and absenteeism. What?s interesting is that up to 90 percent of incidents are due to human error, not faulty equipment or other factors.

Aug 1, 2013

By Dave Ragland

The SDSU tunnel and underground station are the first of these type facilities to be constructed by the Metropolitan Transit Development Board. Because there is no previous experience, and because tunneling activities are associated with some risk, he MTDB has undertaken a very proactive and wide reaching program to identify and control risks during construction. Finally, because the tunneling activity and underground station is on the San Diego State University, MTDB is working closely with their staff to identify construction impacts and mitigation’s, and thus ensure a quality project for both agencies.

Jan 1, 2001

By Panshi Xie, Xicai Gao, Yi Luo, Youfu Zeng, Yongping Wu, Shenghu Luo

This research investigates roof deformation and failure characteristics, as well as mechanical interaction between the panels of the roof strata above two adjacent working faces in a steeply inclined coal seam. Physical modeling with photogrammetry measurement method has been employed in this investigation. The movement of roof strata and section pillar, as well as the stratum morphological characteristics, was quantitatively analyzed. Results show that the roof movement direction above the two panels has zoning characteristics, especially in the lower panel. Roof migration in the lower panel of the working face is larger than that in the upper panel. The roof to floor closure perpendicular to the seam direction is larger than the sliding along the seam. The maximum roof concave and convex bending occurred at the middle and upper parts of both panels; the roof bending in the upper panel mining area indicates a larger mining disturbance induced by lower panel mining. The void ratio contour of the lower panel is an asymmetrically arched shape, which is different from that of the upper panel area. The higher roof strata above the upper panel exhibit separation and breaking, whereas the lower roof exhibits compression due to mining in lower panel. The section pillar is compressed and slides slightly, which aggravates the mechanical interaction between the panels and increases the caving height of the roof over the lower panel and the periodic weighting intensity

By Panshi Xie, Xicai Gao, Yi Luo, Youfu Zeng, Yongping Wu, Shenghu Luo

This research investigates roof deformation and failure characteristics, as well as mechanical interaction between the panels of the roof strata above two adjacent working faces in a steeply inclined coal seam. Physical modeling with photogrammetry measurement method has been employed in this investigation. The movement of roof strata and section pillar, as well as the stratum morphological characteristics, was quantitatively analyzed. Results show that the roof movement direction above the two panels has zoning characteristics, especially in the lower panel. Roof migration in the lower panel of the working face is larger than that in the upper panel. The roof to floor closure perpendicular to the seam direction is larger than the sliding along the seam. The maximum roof concave and convex bending occurred at the middle and upper parts of both panels; the roof bending in the upper panel mining area indicates a larger mining disturbance induced by lower panel mining. The void ratio contour of the lower panel is an asymmetrically arched shape, which is different from that of the upper panel area. The higher roof strata above the upper panel exhibit separation and breaking, whereas the lower roof exhibits compression due to mining in lower panel. The section pillar is compressed and slides slightly, which aggravates the mechanical interaction between the panels and increases the caving height of the roof over the lower panel and the periodic weighting intensity

By F. Block, K. Kohli

Outcrop barrier pillars serve to keep mine personnel and the public safe from sudden uncontrolled flows of water accumulated in active and abandoned underground mine workings. When an outcrop barrier fails, the result is an outbreak of water to the surface and is termed as blowout. Mine blowouts are associated with above-drainage mines and can occur through the coal outcrop and sealed portals. A blowout is often catastrophic, a threat to the people on the surface living or working in the path of a potentially large flood. In addition, blowouts can destroy homes, cause landslides and severe erosion and release pollution and acid mine drainage. This paper provides guidance on the planning, design, evaluation and inspection of barriers to address the problem of mine blowouts associated with above-drainage coal mines.

Jan 1, 2007

By Don Phelps, Dean Brox, Peter Procter, Andy Saltis, Tom Morrison, Jeff Pringle

The Greater Vancouver Water District is currently constructing the Seymour-Capilano Water Filtration Project to enhance the quality of drinking water in the Vancouver metropolitan area. The Seymour-Capilano Water Filtration Project comprises the 1,800 million litres per day Seymour-Capilano Filtration Plant, the 1,080million litres per day Capilano Pumping Station, twin tunnels with associated shafts, and the Capilano Energy Recovery Facility. The twin tunnels will convey raw water under pressure from the Capilano Reservoir to the Seymour Filtration Plant and return treated (filtered) water for distribution. The Twin Tunnels component of the project comprises twin, 3.7 m diameter, 7.2 km TBM bored tunnels, the 180 m deep Seymour Shaft as the main launch shaft, and two 4 m diameter, 268 m deep raise bore exit shafts at Capilano. The Twin Tunnels have been planned as predominantly unlined tunnels sited at depth entirely within granitic bedrock and cross under two major buried glacial valleys of breadths in excess of 1500 metres that are filled with glacial sediments to depths up to 200 metres. The maximum overburden along the tunnel alignment is approximately 400 metres. Comprehensive site investigations and studies were completed during the detailed design stage of the project. The construction of the twin tunnels started in the fall of 2004 and is planned to be completed by mid-2008.

Jan 1, 2005

By W. H. Schiffbauer

NIOSH has developed an active proximity warning system called HASARD (Hazardous Area Signaling and Ranging Device) for warning workers as they approach known dangerous areas around heavy mining equipment and other dangerous work zones. HASARD is composed of a transmitter and a receiver. The transmitter generates a 60-kHz magnetic field using one or more wire loop antennas. Each antenna is adjusted to establish a magnetic field pattern for each hazardous area. The receiver, worn by the worker, is a magnetic field strength meter. The received signal is compared against preset levels which are calibrated to identify levels of danger. The receiver outputs can include visual, audible, and vibratory indicators and it can also be made to disable machine functions. HASARD was field tested on a Joy 12 continuous miner, a Komatsu 210 M Haulpak, and on a highwall launch vehicle. Slight modifications were made for each application. HASARD provided warnings as designed and proved to be rugged enough to withstand the harshest of production environments.

Jan 1, 2001

By Eduardo Pimenta de Melo, Rambabu Pothina, Rajive Ganguli

Sensors are everywhere in the mining industry, with sensor information being used to monitor and operate processes. Therefore, when sensor information is wrong, economic losses can occur. Unfortunately, sensor errors are usually not detected till they become large. This is problematic as most calibrate their sensors no more than once a year (Beamex, n.d.). Using principles of data mining, where all relevant information is tapped to glean hidden information, Pothina [8] designed an algorithm to detect errors in temperature sensors in gold stripping circuit in Pogo mine, Alaska. This paper continued his work by analyzing the behavior of the algorithm on baseline data and testing the algorithm in new data and under more rigorous conditions. It also made a change to the algorithm. The modified algorithm performed very well in the new data. It also worked well under the new error conditions. Three types of errors were seeded, a fixed additive error (+ 2%), a fixed subtractive error (− 2%), and a noisy, normally distributed error, with a mean value of + 2%. Artificially seeded errors were detected within about 20 gold stripping cycles. Inherent bias in operation impacted algorithm performance by increasing the number of cycles needed to detect errors. This paper reinforced Pothina’s [8] conclusion that when data mining approach is used, sensor errors can be detected even when they are pretty low. Significant economic losses can thus be minimized.

By None None

Life as a mining/mineral professional doesn’t leave much time for perusing 20-page technical papers. Yet, being technologically savvy is part and parcel of a successful career in this industry. What’s an intelligent, well-informed person to do?

Several industrial-scale HydroFloat separators have recently been installed at Mosaic?s South Fort Meade beneficiation plant for the purpose of improving phosphate recovery and throughput capacity. This technology was implemented after numerous laboratory, bench-scale and on-site, pilot-scale test campaigns. The results from this detailed test work provided sufficient justification for the complete retrofit of the existing coarse and ultra-coarse flotation cells. Data indicate that the metallurgical results obtained with the full-scale separators are consistent with that obtained during both the bench- and pilot-scale evaluations. The benefits, theory of operation and commissioning of the equipment are also discussed.

Jan 1, 2007

By Florence Ntsiful, Eric Stemn

Exposure to whole-body vibration has been recognised as an occupational hazard in the mining industry, especially in the operations of earthmoving equipment. Managing whole-body vibration exposures requires periodic measurement of exposure levels to identify priority areas for implementing controls. However, due to different approaches to collecting exposure values, significant variabilities lie in the results. This systematic review is the first attempt to analyse whole-body assessment methods in the mining industry. The aim was to identify how whole-body vibration has been assessed, including the sources of variabilities to improve future research. The PRISMA methodology was adopted for the review and a total of 152 peer-reviewed journal articles were identified. However, only 24 were included in the review, following the application of some inclusion criteria. Descriptive and thematic analyses were performed on the 24 selected articles. Results indicate that whole-body vibration has been assessed as a function of either equipment characteristics, activity undertaken, operator characteristics, measurement approach or the assessment standards. Due to the multifactorial and dynamic nature of wholebody vibration exposures, the variabilities in results are due to the interrelationships between the risk factors of whole-body vibration and the differences in the sample sizes. To identify the sources of variabilities, a comprehensive assessment of all the risk factors, including equipment characteristics, road conditions, operator characteristics, and activity undertaken, is highly warranted. Finally, research gaps and directions for future research have also been discussed.

Dec 21, 2022

By B. Arvidson

Computer-controlled machine sorting may, if properly applied, have a dramatic effect on overall economics of a mine operation. Radiometric and photometric sorters have been used for many years and new developments will be reported, such as a sorter for fine particles and a conductivity/magnetic sorter. Application examples with emphasis on precious metals will be given. Economics for some of the projects will be reviewed and discussed. Sorting underground is shown to be particularly attractive, but machine sorting would be profitable in most cases based on savings in transportation and milling/beneficiation costs only.

Jan 1, 1987

By Christopher J. Bise

INTRODUCTION The control of nuisance water in a mine is extremely important; left uncontrolled, nuisance water can have a severe effect on haulage, ventilation, production, and the health and safety of miners. To control water in mines, a four-step process is followed: (1) prevention, (2) collection, (3) transportation, and (4) treatment. This chapter will be devoted to the collection and transportation of mine water because prevention is usually dictated by pre-mining conditions and initial planning, while treatment is variable and highly site specific. A mine drainage system is nothing more than a collection of gathering points (sumps), machines that impart energy to the fluid (pumps), transportation ducts (pipes), and control devices (fittings, valves, etc.). A pump does not pull the fluid up the suction pipe; atmospheric or external pressure pushes the liquid up the suction pipe to the pump. All references in this chapter will be to centrifugal pumps, due to their popularity for mine drainage. PUMP CHARACTERISTIC CURVES The performance of a pump is plotted on a graph as an indication of its characteristic. To develop the data points, a test facility similar to that shown in Fig. 1 is established. The calibrated Venturi meter is used to measure quantity, the Bourdon gage measures pressure, and the wattmeter measures power input. Various discharge pressures are obtained by throttling with a gate valve in the discharge pipe. Quantity and power are measured at each of these pressure levels, giving the necessary data for plotting the characteristic curves. Fig. 2 shows a typical characteristic curve for a centrifugal pump. Notice that pressure is measured as so many feet of vertical water column above the outlet level, or head. Knowing the quantity (in gallons per minute), head (in feet), and power input (brake horsepower), the pump's efficiency can be plotted based upon the following relationship:

Jan 1, 1986

By Derek Brennan, Donald Brennan

"The existing Rondout West Branch Tunnel (RWBT) is part of the Delaware Aqueduct which has been in service since 1944 and accounts for more than 50 percent of New York City’s water supply. In early 2015, the New York City Department of Environmental Protection contracted Kiewit-Shea Constructors, AJV (KSC) to construct the Rondout West Branch Bypass Tunnel project (Rondout) in order to mitigate the leakage of 132 million L/ day (35 million gpd) of water from two areas of the existing tunnel; the Roseton and Wawarsing areas.The scope of the Bypass Tunnel 2 project is separated into two distinct phases. Phase 1 consists of completing the shaft sinking to a depth of approximately 274 m (900 ft) at shaft 5B, 213 m (700 ft) at shaft 6B and the excavation of approximately 3,850 m (12,500 linear ft) of tunnel at a diameter of 6.6 m (21 ft 7 in). This phase also includes the installation of 2,804 m (9,200 linear ft) of 4.8 m (16 ft) diameter steel interliner pipe through the new bypass tunnel with cast-in–place concrete liner for a finished diameter of 4.2 m (14 ft). Access chambers at the top of shafts 5B and 6B will be constructed for access and housing of the mechanical and electrical equipment for supporting pumps and valves.Included in phase 2 is the additional excavation from shafts 5B and 6B to the RWBT, and the drainage tunnel to remove ground water infiltration from RWBT. This work will be completed during a scheduled shutdown of the RWBT and will include approximately 31 m (100 ft) of excavation of the two connection tunnels. Additionally, construction of the permanent plugs within the RWBT will be undertaken. Figure 2 shows the layout of the work.Access to the work through the deep shaft at site 5B was critical to the success of the project. The hoisting system needed to be multi-functional to handle the different types of construction from drill and shoot of the shaft, starter and tail tunnel, the assembly of the tunnel boring machine (TBM), the excavation of the TBM tunnel including the supply of the precast segmental liner, the grouting operations, the installation of the steel interliner pipe and the cast-in-place concrete as well as ingress and egress of personnel. The production of the TBM operations was critical to the schedule of the project. This required a quick cycle for muck haulage and supply of the precast segmental liner in order to keep pace with the excavation time of the TBM. For TBM assembly, components were limited to a maximum weight of 104 t (115 st) for a single lift. Various cranes were analyzed for hoisting, however, none would meet all of the citeria. Therefore, the project team selected a specialized hoisting system designed in house in conjunction with Timberland Equipment Ltd. that consisted of a total of 14 separate hoists and winches with a total of more than 2,833 kW (3,800 hp)."

Mar 1, 2019

By L. P. James, W. W. Atkinson

Utah has produced about one billion troy oz. (31.7M tonnes) of silver, more than any U.S. state except Idaho. Several very high grade ore systems, now closed, occur within large polymetallic limestone-hosted districts related to plutonic complexes. These Utah mines fed several major lead smelters for nearly a century. Interaction of magmatic chloride-rich fluids with carbonate rocks localized significant bonanzas within these districts. A low sulfidation state was produced in the fluids by their passage through limestones. The Bingham porphyry mine has also yielded more byproduct silver than other porphyry copper-gold systems. Away from exposed intrusive rocks, some large silver-only systems occur in Mesozoic sandstone and in caldera-related veins in volcano sedimentary rocks. Thick permeable latest-Proterozoic basement meta quartzite sequences present beneath western Utah may have been important, as perhaps they were in the Coeur d’Alene district of Idaho, in providing chloride and silver-rich ore fluids. However, it is clear that specific Tertiary magmatic events played an essential role in the evolution of the Utah silver-rich metallogenic province. The largest silver districts in the state are genetically related to porphyritic plutonic rocks.

Jan 1, 2000

By P. Sangurmath, C. Gundewar, M. Riyazulla, V. Vasudev, N. Shadaksharswami

Dharwar craton in the southern Indian shield, comprises the Neoarchaean foreland in the west and a relatively younger accretionary complex composed of granitoids and intervening gold-bearing volcano-sedimentary belts. The Hutti schist belt hosting a major gold producing mine is situated in the northern part of the eastern Dharwar craton. It is a horse-shoe shaped structure comprising predominantly of pillowed metabasalt of tholeiitic composition with minor amounts of clastic sediments and felsic volcanic rocks. The belt is intruded on all sides by circular to tabular bodies of granites and granodiorite. Important gold deposits are located at Hutti, Hira-Buddini and Uti villages. Felsic volcanics in the Hutti belt occur as tabular bodies of quartz porphyry and breccia. Two of the gold-bearing reefs in the Hutti mine, Viz., Middle and Strike reefs are intimately associated with tabular sub-vertical sheets of mylonitic quartz-feldspar porphyry intruding pillowed metrabasalt. In Uti mine area, the felsic volcanics occurs as a tabular body. At Hira-Buddini, the felsic volcanic occur as a irregularly shaped sheet in pillowed metabasalt. Mineralogical and geochemical studies suggest that the felsic volcanic rock in Hutti mine area is a rhyolite and at Uti and Hira-Buddhini it is of dacite composition. Scheelite occurs as veins, veinlets, stringers and blebs along fracture planes of felsic volcanics in the Hutti mine area, whereas at Uti and Hira-Buddini it is insignificant. On the basis of spatial association of metabasalt and felsic volcanics and on geochemical grounds, we interpret that the felsic volcanics might have originated by the partial melting of basalt. REE patterns of the granite, granodiorite and metabasalt of Hutti are similar to each other indicating that they could be co-magmatic. However, REE in the Hutti felsic rocks is significantly higher than in Uti and particularly Hira-Buddini mine areas. The two felsic volcanic samples drawn away from the mineralized zone from all the three mine areas were analyzed for tungsten. In Hutti one sample assayed 0.15% and another 0.062%. At Uti, in one sample it assayed 0.056% and another less than 1 ppm, whereas at Hira-Buddini, it is less than 1 ppm in both the samples. The spatially associated basalt analyzed 23 to 235 ppm tungsten, whereas granites and granodiorites have very low (<1 ppm) tungsten. Therefore, the source of tungsten in the felsic volcanics of Hutti area could be traced to metabasalt. The absence of significant amount of tungsten in the felsic volcanic of Hira-Buddini could be attributed to the lack of REE enrichment compared to REE in Hutti and Uti felsic volcanics.

Jan 1, 2007

By MATT RENAUD, Mustafa Kumral

Mining corporations have spread their operations worldwide in the last few decades. The reason behind widening operations geographically can be seen as it being part of a risk diversification strategy. Given that the technical, financial and social risks are high, favorable deposits, taxation regimes and legislative frameworks create incentives for international mining operations. On the other hand, international mining activities add the risks of permitting, investing, operating and decommissioning to the corporations. These risks could emerge from defaulting, corruption, resource nationalism, social license to operate, and political and legislative uncertainties and instabilities.

By Georgene Renner, William R. Yernberg, Steve Kral

ABB offers complete electrical revamps of mining shovels with ac or dc drives, drive control, frequency converters with insular gate bi-polar transistor technology, intelligent control packages and visualization. Many of the world’s shovel excavators and draglines (walking excavators) were built in the1980s. After 15 to 20 years of round-the clock operation in openpit mines, these machines start to feel their age. Electrical parts are particularly vulnerable. Their performance deteriorates and availability and productivity fall. Even with regular ser-vice and maintenance, a machine of this age will accumulate 400 hours of unscheduled downtime a year. The need for a replacement becomes pressing, but the expense is often prohibitive.

Jan 1, 2005

By R. Strandahl

As one of the largest private utilities globally, E.ON currently operates hard coal fired power stations in with a total installed capacity of some 20.000 MW: These thermal power plants consume domestic coals but are increasingly dependent on imported seaborne traded coal (in 2009 approx. 17 million t). Knowing that the company’s reputation and credibility depends in part on how E.ON lives up to the responsibilities along the entire energy value chain, E.ON takes a collaborative approach with the various suppliers. Hence, E.ON’s responsible policy also applies to the procurement of coal; the utility launched in 2009 a comprehensive Corporate Responsibility program with special focus on supply-chain audits. One of the first coal audits focussed on the Cerrejón coal mine in North Eastern Colombia. The authors will share the key learning’s and experience from the Colombian audit jointly conducted with an independent auditor and E.ON experts from the Corporate CR and E.ON Energy Trading.

Jan 1, 2011

By Malte J. M. Gurgel, Axel Preusse

Recent three-dimensional surveying techniques have opened up new opportunities for the registration and monitoring of underground cavities. There are essentially two main methods available: Laser scanning, which is used both above surface and increasingly underground, and photogrammetry, which is also experiencing a renaissance with techniques like structure from motion through the algorithm-based orientation of high-resolution images. Both methods provide the capability to reconstruct reality by various 3-D products like points clouds and meshed models. However, they differ significantly in the steps of registration and calculation as well as in the resulting evaluation options.