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The earliest caveman, very much a minority group, in the face of great adversity and person- al peril, had to take his livelihood by stealth or force of arms - aided by some degree of reas- on and ingenuity. He was pretty much a law unto himself. As time went on, his type became more numerous; and, after bumping heads with the- tough bloke who lived in the cave across the valley, he decided that perhaps he ought to try to get along with him. Perhaps he could trade some over-ripe emu meat for that `roo skin that he had tried to take. Then too, next time he wants a woman, he had better use a lighter club and just stun her a little - that last one was pretty badly bashed. Perhaps he should keep her around the cave and train her to keep the fire going, gather some roots, and skin the game. Those joeys of hers are kind of cute too. Of course they eat, and it would necessitate bringing in more food. So man gained increasing responsib- ilities to his family and neighbours. He domesticated animals, learned that he could cultivate certain plants that were palat- able and would supplement the meat diet, and found that he could modify earth materials to make tools - he became a grazier, a farmer, a miner and a manufacturer. He ceased to be nom- adic and community life came into being. This complicated life and made more rules essential.

Jan 1, 1974

In the early days of minimal environmental protection awareness and unreasoning economy development pressures, little attention was paid to growing environmental concerns in Fuxin colliery, especially the air pollution problem due to the long term mining activities. In order to determine air quality concentration levels, a new technique for synthetic assessment of ambient air quality by using the extension of matter-element method is proposed in this paper. The air pollutants data such as Sulphur Dioxide (SO2), Carbon Monoxide (CO), Nitrogen Oxides (NOx), Total Suspended Particulates (TSP), Particulate Matter (PM10), and dustfall collected at four different air quality monitoring stations located in four districts of Fuxin colliery is used. The results obtained indicate that TSP, PM10, dustfall and SO2 are the predominant pollutants. Other pollutants such as CO and NOx are also detected in Fuxin colliery. The air pollution comes mainly from industrial emissions, mining activities and the abandoned gangue stockpiles. Compared to those applied to other mathematical assessment methods, it is demonstrated that the extension of matter-element model is quite appropriate for air quality assessment.

Jan 1, 2006

By Dennis Ortega, Rich Kramer

After several operational improvements to FMC's Westvaco Mine Longwall, an ergonomic and operational bottleneck resulted at the mobile belt tail/rigid conveyor junction. Ergonomic hazards, cutting time losses, and spillage problems near the belt tail were identified and targeted for improvement. FMC Westvaco, consulting with FMC Material Handling Division, corrected the bottleneck using an expandable/retractable conveyor system to fill the gap between the mobile belt tail and the rigid conveyor structure. This paper explains the operational expectations, defined before; the challenges, encountered during; and the real outcomes, measured after the installation of an expandable/retractable conveyor system.

Jan 1, 2002

By James P. Hambleton, Anastasia Nally

This work focuses on the numerical simulation of multi-plate anchor systems (e.g., helical anchors) in sand subjected to vertical loading. In assessing the stiffness and capacity of these multi-plate anchor systems, full awareness of the abilities and limitations of the various analysis methods must be understood. This work first summarizes studies completed by others and then goes on to assess the failure mechanisms of multi-plate anchors in sand and the influence of (1) plate width-to-depth ratio, (2) number of plates, and (3) relative positioning of plates. The analysis makes use of (1) conventional limit analysis, (2) so-called modified limit analysis that employs reduced strength parameters to account for the influence of soil dilatancy, and (3) the displacement-based finite element method, which considers elastic as well as plastic deformation leading to failure. The work critically reflects on limitations in the current analysis methods for helical ground anchors. INTRODUCTION Helical anchors are a relatively low cost foundation type, typically consisting of a steel rod and single or multiple plate attachments. In recent decades, they have seen rapid growth, and as outlined by Merifield and Sloan (2006) and Hambleton et al. (2014). Design techniques for helical anchors have previously been predominately empirical, as much of the past research in this field is experimentally based. It is common practice for helical anchors to be modeled as horizontally oriented plate anchors in both numerical and experimental analysis. This work focuses on analysis based on the finite element method, including so-called finite element limit analysis and the conventional displacement-based finite element method, with some comparisons made to experimental studies. Numerical simulation of anchor pull-out capacity in cohesionless soils is stunted by the many difficulties faced when using numerical analysis with cohesionless soils. Additional variations can be seen when comparing the serviceability based load capacities to the ultimate load. In this work, both the force-displacement response (stiffness) and the ultimate anchor capacity are assessed, with more focus on the latter. This work focuses only on analysis techniques for multi-plate anchors with vertical loading in cohesionless soils. Many studies have been completed in this area, some of which assume a rectangular plate in a plain strain model (Rowe & Davis, 1982; Merifield & Sloan, 2006; Cerfontaine et al., 2019). Whereas others use axisymmetric conditions (Baker and Kondner, 1966; Saeedy, 1987; Murray & Geddes, 1987; Ghaly & Hanna, 1994; Sakai & Tanaka, 1998; Merifield et al., 2006;) and minimal studies considered both axisymmetric and plane strain in the one study (Vesic, 1971; Tagaya et al., 1988; Murray & Geddes, 1987; Sarac, 1989).

Jan 1, 2019

By Hossaini SMF

The applicability of four empirical strength criteria for rock masses, namely, Hoek and Brown, Bieniawski - Yudhbir et al., Ramamurthy - Arora and Johnston - Sheorey et al. has been tested against the triaxial test data for jointed plaster of Paris of Arora. The following modified Bieniawski criterion shows best agreement with the triaxial test data for jointed plaster of Paris: 611=1+B(63)O.825 acm 6cm where a1= axial compressive stress at failure, MPa; a3 = confining pressure, MPa; acm = uniaxial compressive strength of jointed plaster of Paris, MPa; and B = - 3.988 + 9.674 (aim ) -0.185 The modified Bieniawski strength criterion can be used to estimate the strength of a coal pillar, based on a knowledge of stress distribution in it.

Jan 1, 1992

The applicability of four empirical strength criteria for rock masses, namely, Hoek and Brown, Bieniawski - Yudhbir et al., Rarnamurthy - Arora and Johnston - Sheorey et al. has been tested against the triaxial test data for jointed plaster of Paris of Arora. The following modified Bieniawski criterion shows best agreement with the triaxial test data for jointed plaster of Paris:- where st = axial compressive stress at failure, MPa; s3 = confining pressure, MPa; scm = uniaxial compressive strength of jointed plaster of Paris, MPa; and B = - 3.988 + 9.674 (scm )-0? 185 The modified Bieniawski strength criterion can be used to estimate the strength of a coal pillar, based on a knowledge of stress distribution in it.

Jan 1, 1992

By H J. J Boshoff

Pit lakes, as a final void after completing open cut mining, are in most cases unavoidable. Initial mine designs and approvals require consideration and assessment of closure objectives, legislation and stakeholder acceptance to ensure suitable understanding of the closure liability. Mining companies undertake studies and engineering during the planning, operational and closure stages of mining to identify closure options for the final voids, which would be sustainable. Without adequate planning prior to and during the life of the mine, options during the closure stage become limited resulting in costly closure works or long-term liabilities. Engineering consultants provide a specialist service in the assessment of long-term pit lake water levels and characteristics. Ongoing advances in mining methodology and technology, coupled with improved data collection and data management aid in a better understanding of the complexities in estimating long-term pit lake water levels and characteristics. Closure objectives developed during the planning stage sets the requirements for long-term pit lake water levels, which could require maintaining a water level and pit water or discharge water quality. A variety of approaches could be used to assess these closure scenarios each requiring specific data and methodologies. Typically, limited data is available during the planning stage, which results in assumptions based on past experience and relevant case studies. Closure assessments are revisited during the life of mine and leading up to the closure stage, during which additional site-specific data is available improving the accuracy of the assessments.CITATION:Boshoff, H J J, 2018. Assessment of approaches, data requirements and methodologies for estimating long-term pit lake water levels, in Proceedings Life-of-Mine 2018, pp 28–31 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By Renata Cristina Teixeira

The lubricant oil is a complex mixture of different basestocks and additives. Engine oils evolved from the use of pure mineral basestocks back in the early years of automotive industry to the advent of synthetic, fully formulated, low ash lubricants. This evolution was driven by a number of factors, such as new engine designs, extended durability needs, increased fuel economy needs, environmental concerns, feedstock prices and availability and legal issues. This paper uses technology prospecting on literature and patents databases to allow an investigation on the historical evolution of engine oils. Main basestocks (mineral, hydrotreated, polyalphaolefins, esters) and additives (antioxidants, antiwear, friction modifiers, detergents and dispersants) are characterized according to their research effort. Technology prospecting data is crosschecked against the evolution of engine oil classes, allowing an analysis of how the main drivers push the development of lubricant oil quality. A research effort was identified in late 1990’s until mid-2000’s and related to the adoption of chemical limits for lubricants. Different patterns for the articles and patents publication account for the high value technological knowledge has in this industry. Technology prospecting is seen as a useful methodology for the understanding and forecast of lubricant technology movements.

Jul 31, 2018

By C. E. Dunn

Paper presented at the 28th International Geological Congress held in Washington DC, July 1989 (International geochemical mapping sessions). Evidence is accumulating that reconnaissance-level biogeochemical sampling can provide valuable insight into the chemistry of the substrate. Problems such as seasonal variations in plant chemistry and the lack of a universal biogeochemical sample medium may be circumvented by adopting normalising procedures. The planet can be divided into a few climatic zones, each of which is characterised by one or two common plant genera. If it can be demonstrated that the chemical differences between certain species of a single genus are small - as is suggested by studies of boreal forests - it would seem feasible to apply biogeochemistry as a low-density geochemical mapping tool. The technique could prove particularly useful for assessing the substrate chemistry of areas of dense forest, rugged terrain and difficult access by employing airborne sampling of trees from helicopters

Jul 1, 1991

By M. S. Dotto

The knowledge of the explosive/ rock mass interaction process is important in predicting blast performance. It includes understanding rock properties, energy usage, and attenuation in the rock mass. The paper proposes a method to quantify blast-induced rock mass damage from the field measurements and apply it to modeling blast fragmentation.

Feb 1, 2020

By Ajoy K. Ghose

INTRODUCTION Longwall mining made its debut in Indian coal mining scene around 1900. Despite this headstart, the application of the method has been slow and halting. Currently, there are some 16 operating longwall faces only in different Indian coalfields contributing to perhaps less than 3 percent of the total underground coal production. Ambitious plans for expansion of longwall mining notwithstanding, apprehensions on the cavability of Indian coalmeasure roof rocks and some unsavoury experiences with face collapses in caved longwalla have impeded wider adoption of the technique. Between 1960 and 1983, some 41 caved longwall faces were worked in Jharia, Raniganj, Karanpura and Korba Coalfields in India, of which 6 faces reportedly had collapsed(1). The first powered support longwall face was started in August 1978 at Monidih colliery which marked a major step forward in the introduction of advanced technological system in Indian coal industry. This paper attempts to analyse critically the experiences with longwall ground control in caved longwall faces in India. Experiences from powered support faces at Monidih, Dhemomain and Pathakhera are synthesized to provide an appraisal of the present status of caved longwall faces under the Indian coalmeasure roofs, which thus far have been characterised as “massive”. The geotechnical site factors at the powered support faces are evaluated and conclusions drawn on the pre-assessment of caving characteristics and support resistance required at the faces.

Jan 1, 1984

By E. M. Cukrowska

The evaporative pan complex consists of two adjacent seasonal pans. These pans carry an exceptionally high salt (TDS) load due to over 50 years of effluent discharge via the pipeline from mines. The nutrient, heavy metal, radionuclide load in the water and sediments of the pans are very high affecting groundwater around the pans. The groundwater in the region contains TDS > 40 000 mgl-1 and sulphates > 7000 mgl-1, whereas groundwater in areas assumed to be unpolluted by mining activities have TDS < 500 mgl-1 and sulphates < 200 mgl-1. The extent of continuity between the pans and the groundwater is unknown, although there appears to be seepage of contaminated groundwater into the river system.

Jan 1, 2006

By M Allen

By its nature, the mining industry is energy and emissions intensive. In the future, the world will still require the outputs of mining but the industry will need to adapt to the low emissions economy. Understanding the risks of climate change to a particular site or at a company level is key to managing this transition.CITATION:Allen, M, 2018. Assessment of climate risk in the Australian mining industry, in Proceedings Life-of-Mine 2018, pp 13–16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By D. Stone, M. Le Roux, Q. P. Campbell, M. Fofana

Float-and-sink analysis is widely used in the coal industry to obtain washability data, yielding important information about beneficiation potential and performance. This method is associated with health and environmental problems, and research into alternative densimetric methods is important. The RhoVol is a new technology developed by De Beers Group Technology South Africa (DebTech) for the image-based generation of densimetric data from ores. The analysis is done on a per-particle basis, within a size range of +3 mm –8 mm. In this paper we compare the established methods used for the float-and-sink analysis of coal with a new method using RhoVol. The aim of the study was to determine the validity of the information obtained from the RhoVol analyser by performing comparative densimetric analysis on three different coal samples. The results showed that the RhoVol method was more rapid, safe, and precise, but tended to consistently underestimate the density of the coal sample, probably due to varying coal porosity.

Oct 3, 2023

By J. W. Oberholzer

Problems with gravimetric sampling have led to the establishing of a computer linked tyndallometer dust measuring system. Preliminary tests conducted with the system indicate that the system can be used to do correlative exercises between mining activities and dust levels. The system also allows occurrence characteristics of dust levels to be determined. Use of this equipment will enable dust allaying methods to be tailored to the specific underground situation.

Jan 1, 1987

By A. Nhasengo

Paper written on project work carried out in partial fulfilment of B. sc. Eng (Mining Engineering) The purpose of this investigation was to assess the mining strategy for steep reefs at Mine A mine in 2005 and 2006. Reefs steeper than 35° were discovered when production commenced at the mine. At that time reefs steeper than 35° were not popular in South African tabular gold mines, therefore new techniques of mining them had to be developed. The underhand mining method was chosen for this purpose. The project was about assessing ventilation, support costs, local support cycles, adherence to the mine?s support standards, mine planning and efficiencies of the underhand mining method. The project work was covered by doing a literature research for underhand mining methods and performing a literature review of the mining methods, support methods, ventilation standards at Mine A. Underground visits were conducted at Mine A mine for data collection, and Mine B was visited to obtain information on support costs and efficiencies. During the investigation it was realized that the underhand mining method was an appropriate method for mining steep reefs; however, there were some challenges related to ventilation and support installation. Efficiencies could be realized with the underhand mining method and planning and scheduling were not different from breast mining.

Jan 1, 2007

By Dal Sun Kim, Michael K. McCarter

"Comminution (crushing and grinding) of rock materials is energy-intensive and expensive. Mucheffort has been directed to improve the efficiency of conventional milling practice, but relatively littleattention has been given to the potential benefits of blast-induced damage on comminution processes. To help assess this effect, research has been conducted at the IRECO Laboratory and the Generic Center for Comminution at the University of Utah. The objective of this research is to investigate the effect of shockinduced “crack-like” damage on rock properties and subsequent breakage efficiency for three petrologically different rock materials under laboratory conditions. In order to evaluate the effect of shockinduced damage, a quantitative measure of rock damage is needed. For this purpose, a scalar variable (0) is proposed."

Jan 1, 1993

By V. Voller

A relatively simple model of grinding which incorporates both the Bond grindability equations and the population balance equations has been extended to form a comprehensive simulation package that can describe most kinds of conventional grinding circuits. The package has two programs, with the first consisting of an input program which helps the user to specify the prescribed circuit, while the second program performs the actual simulation. The package serves two main purposes - i) as a check on mill design, with the output providing not only predictions for the product passing size but also of the full product size distribution, and ii) as a means to assess the likely effects on the product size distribution of operating under different sets of conditions.

Jan 1, 1981

By J. P. Mogan

As diesel exhaust contains a mixture of several materials of varying degrees of toxicity which interact to a currently undefined extent in their effects on health, the prescription of a quantity of ventilating air to dilute the exhaust to a safe level is necessarily, to some extent, arbitrary. Some jurisdictions rely on the application of a safety factor to a single "governing" component (usually nitric oxide for most modern diesel engines). Others specify that the total of the "adjusted" concentrations (actual concentration divided by maximum permissible concentration) not exceed "one" for related constituents (irritant gases for example). Neither of these approaches, however, takes account of the interaction of the gaseous constituents with diesel soot (although many studies verify such interactions), nor do they provide any economic incentive for reducing pollutants which are not included in the criteria for ventilation. Because of these factors, the Canadian Department of Energy, Mines and Resources awarded a contract for a study of the current literature bearing on the "Health Implications of Exposure of Underground Mine Workers to Diesel Exhaust Emissions" (1). One goal of this study was the formulation of a new ventilation criterion. The contractors, Ian W. French and Associates, studied more than 1500 literature citations which they interpreted in a 350 page report and summarized in a companion 1600 page annotated bibliography. In the recommendations section of the report, they defined a new &apos;health effects index&apos; or ventilation criterion "V" as follows: [ ] The contractors consider that a "V" between 3.0 and 4.0 poses a moderate threat to health which could be alleviated by the use of protective equipment such-as filter helmets. If V exceeds 4.0, an increase in ventilation quantity to reduce the pollutant levels is indicated. In the case of mines with a quartz content in excess of 20% in the ore, the contractor recommends that a term. [Quartz]/ [Threshold Limit Value Quartz] be added to the equation, and [2.0 = ?v? = 30] be the range justifying protective equipment, with added ventilation if "v" exceeds 3. A degree of pragmatism was inherent in the development of the equation, as the contractors recognized that the components of the index, if it is to be useful in the near term, should be within current routine underground environmental assay capability.

Jan 1, 1980

By T Huynh, V Matanitobua, J Zheng, B N. Noller, J C. Ng, H H. Harris

A risk assessment was undertaken of the aquatic ecosystem and bioaccumulation of metals and metalloids in fish at the Leichhardt River, Mount Isa, Queensland. Residual contamination of metals and metalloids in Leichhardt River sediment was assessed and arose from mine practices using river discharge in the 1940s. The ecological risk assessment of sediments involved comparison of the concentrations of heavy metals and arsenic with those of the ANZECC/ARMCANZ (2000) Interim Sediment Quality Guidelines (ISQG). Results indicated that all sites including the background site exceeded one or both the ISQG-high and ISQG-low trigger values based on total concentrations. A lesser number of sites exceeded the ISQG-low trigger values following the 1 M hydrochloric acid extract step, which was used as an indication of bioavailability. An additional risk from particulate matter in river sediment is that acute human toxicity from the consumption of fish contaminated with metals and metalloids is unlikely. The potential risk was assessed by comparing with the maximum levels set by FSANZ (2010) for fish consumption by children and adults. In general, the liver of the fish have higher heavy metal and metalloid concentrations compared to the muscle. Frequent or regular consumption of fish from the Leichhardt River that exceed maximum levels (ML) of heavy metals and metalloids is not recommended. Risk analysis showed that an adult can consume up to 5 kg of fish fillets every day from fish caught at the man-made Lake Moondarra downstream on Leichhardt River and still be within safe consumption levels whilst a child can eat up to 1 kg daily.CITATION:Noller, B N, Ng, J C, Matanitobua, V, Harris, H H, Zheng, J and Huynh, T, ?2014. Assessment of ecotoxicology and health risk from bioaccumulation in fish of heavy metals and metalloids from historical mine practices in the Leichhardt River, Queensland, Australia, in Proceedings Life-of-Mine 2014 , pp 337–348 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014