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By D. W. Smellie

This paper is a review of technological progress in mining geophysics during the past decade. This has been the most significant period in the history of mining geophysics. Among the already existing; techniques, instruments for ground -magnetic and electromagnetic prospecting, were developed that are more, portable and faster to operate. Induced polarization equipment came into widespread use. Airborne instruments of various types became available and were used to survey large areas. Drillhole instruments were developed and have had some use, and it is to be hoped will be used to a greater extent in the future. Two revolutionary new methods, the AFMAG and INPUT, were developed. The wisdom of attempting to cover such a broad field in a single paper might be questioned. There is the inevitable problem that each topic must be discussed very briefly. However, while papers describing individual instruments have appeared, many have yet to be described in the technical literature. The evolution of the ground magnetometer and electromagnetic instruments has not been discussed. It is only recently that a review article has appeared on airborne EM. The existence of review literature on some topics has meant that they are given less emphasis in this review than those topics inadequately covered. It will also be observed that stress is laid on "chose instruments that are generally available to the mining industry rather than those developed by individual exploration companies for their own use.

Jan 1, 1963

By A. Delgado-Jimenez, O. J. Restrepo-Baena

"Sustainability is a concept that involves several aspects like social, economy and environment. For the concept of sustainable mining is an action that involves to do more in social acceptance, distribution of welfare, an stable economy and the environment. Understanding the mining operation that creates a new state that is necessary to prepare and conduct searching for the best results in sustainability. The results of sustainable mining could be directed to achieve less net environmental impacts, more economic development through the transformation of the natural capital and the social acceptance as the result of good negotiations with the communities in the surroundings. To do that, one option is to create frameworks to planning the regional mining developments that allows the stakeholders to decide and develop different strategies to addresses the sustainability in a mining environment. Strategies based on the understanding of the whole mining business, the environment in which it operates, composed for a natural resources network that interact in a complex system, social system composed by different groups, communities and economies that could be subject to big transformations. INTRODUCTION The mining sector represents one of the most significant challenges for sustainable development, given the magnitude of the impacts that it has on the social and natural systems and the potential to generate welfare associated with its exploitation. Some of the main challenges of mining to contribute to sustainable development are the reduction of the environmental and social impacts of mining operations, to advance in the distribution of benefits in the community and the investing in the development of substitutes. To help in this direction it is necessary to integrate more actors than those who have been considered traditionally in the development of the mining business, and consider the natural environment, communities and the several dynamics generated by the interaction of these elements that contribute to sustainable development. This work provides some useful considerations for sustainable development of mining operations in regions with mining vocation, through the convergence of objectives and the finding of synergies between the existing conditions in the territories and the potential conditions that are generated by new mining developments. A DEFINITION FOR SUSTAINABILITY IN MINING The definition of the Brundtland Commission in 1987 established that sustainable development is ""the ability to ensure that it meets the needs of the present generations without compromising the ability of future generations to meet their own needs""."

Jan 1, 2015

By D. E. Traut

A fluidized countercurrent ion-exchange system was developed, operated, and evaluated by the Bureau of Mines. The system consisted of integrated multiple-compartment absorption and elution columns in which the solution flows are continuous except for short periods when resin increments are withdrawn. The exchange of uranyl sulfate between a simulated acid leach uranium solution and a strong-base, ion-exchange resin together with the subsequent elution with an acidified sodium chloride solution was studied. The effects of the number of sections, section heights, amount of resin withdrawal, and solution flow rates were investigated. Also examined were the kinetic and equilibrium relationships for the absorption step. The experimental data indicate a strong interdependence between variables. Solution retention time appears to be a major limiting variable. The column was efficient over a range of conditions, but close control was needed for optimum operation.

Jan 1, 1975

By R. L. Grayson, R. C. Althouse, M. J. Klishis

The health and safety of employees, efficiency of the operating system, and production are paramount goals in underground coal mining. The section foreman assumes responsibility for making his part of the total system function to meet these goals. However, section foremen often have not been prepared to assume the full range of their responsibilities upon becoming a supervisor. This paper addresses the full range of section foreman responsibilities and concomitant authority. Management principles that must be mastered by him are presented, and performance expectations as well as criteria for their evaluation are examined. The benefits realized from effective foreman training are discussed.

Jan 1, 1987

By T. B. Linde

The Morenci In-pit Crusher and Conveyor System has been designed with safe production and cost savings in mind. Large open pit mines around the world have been installing semi-mobile crushers and linking them with a pit conveyor system to lower unit cost. At Morenci two 60/89 in. gyratory crushers are incorporated into the semi-mobile crushing plants. The ore is reduced to -8 in. and transported out of the mine on a 60 in. steel cable belt. This paper includes an overview of the Morenci In-pit Crusher and Conveyor System from the drawing board to open pit installation and finally a discussion on operating and repair considerations.

Jan 1, 1990

By Andrzej Luszczkiewicz, Kazimierz S. Sztaba

Flotation tailing of Polish copper sulfide ores represents more than 90% of the mass of run-of-mine ore. The tailing contains mainly quartz, dolomite, clay minerals, traces of sulfides, and some accessory minerals. Almost all minerals of the tailing are well liberated and, therefore, any further beneficiation process applied to the tailing is expected to be inexpensive. In this work, results of investigations on utilization of flotation tailing using classification and gravity concentration are presented. It is shown that due to classification of flotation tailing in hydrocyclones, the coarse fraction becomes suitable material for gravity separation providing backfill material for underground mines as well as heavy minerals, a source of valuable rare elements. It was also found that heavy minerals separated by gravity methods contain a significant amount of rare elements such as zirconium, titanium, silver, rare earth metals, and uranium. The light fraction of the gravity separation contains well deslimed quartz particles and meets strict requirements for hydraulic filling material ked for structural support in underground mines. Evaluation of the cost of the proposed technology indicated that investment to implement the method would provide a return within 2-4 years.

Jan 1, 1995

By Adam Bedell, Paul Derby, Brad Crenshaw

Modified contact grouting was introduced almost 15 years ago as a methodology combining traditional contact grouting and consolidation grouting to address groundwater infiltration into hard rock tunnels that utilize cast-in-place concrete as permanent tunnel support. This process has been used on additional tunnels (since initially presented) as a measure to mitigate both groundwater infiltration and exfiltration. During this time, self-sealing grouts have been developed and have been added to the process to further reduce groundwater infiltration that occurs through cracks and discontinuities within the concrete liner itself. This modification is presented and additional results from the grouting process are discussed.

Jun 13, 2021

In this paper, response surface methodology was applied to optimize the experimental conditions for the wet grinding of synthetic rutile. The effects of parameters such as rotation speed, solids concentration and duration of grinding on grinding efficiency were systematically investigated and the process conditions were optimized, using a nonlinear regression model based on central composite design. The statistical analysis of the results showed that in the range studied, the grinding efficiency of synthetic rutile was significantly affected by the rotation speed of the conical ball mill. According to results from analysis of variance, the value of the determination coefficient (R2=0.9989) indicates that the predicted values are found to be in good agreement with experimental values. The optimized experimental conditions were as follows: a rotation speed of 350 rpm, a solids concentration of 27.31% and a grinding time of 50.31 min, respectively. Under optimum conditions, the predicted grinding efficiency of 94.79% is obtained. The experimental values from the validation experiments were well within the predicted value of the model.

Jan 1, 2011

By G. E. McKelvey

A group of gold deposits in southeastern Ecuador, near the town of Zamora, have become the focus of intensive mining activity, due to their extremely high gold grade (unconfirmed reports of about 50 g/t or 1.4 oz per st, or more). The deposits at Nambija and other prospects in the district are hosted by a sequence of sedimentary and volcanic rocks that are present within a large xenolith orpendant within alkalic phases of the Jurassic Zamora Batholith. The xenolith, unknown in size, is composed of various island arc lithologies (limestones, shales, sandstones, tuffs and flows). All have been altered to some degree by skarn-hornfelde alteration assemblages. Mineralized areas appear to be localized within a linear zone containing tectonic and intrusion breccias that cross-cut a complex calcic skarn assemblage developed within the xenolith. Although the nature of the host rocks appears to have exerted some control on mineralization, the high-grade ore is concentrated along north-northeast trending breccias, faults and dikes that crosscut the flat-lying stratigraphy and skarn alteration as suggested by the strong linear trend of workings in the district.

Jan 1, 1991

By W. Hu

Gravity concentration has been the main method for tin ore beneficiation, based on the significant difference of density between cassiterite and gangue in the tin ore. However, with the exhaustion of rich and coarse reserves, the proportion of tin distribution in slime be-comes as high as 50 to 70% and has a size range of -19 urn. In some sulfide tin ore, most of the tin is of the minus 10-urn size fraction, and thus slime processing has gained importance in tin ore processing. Some innovations are being developed, such as the centrifugal cone separator, belt concentrator, slime table, B-M separator, and slime flotation. Direct flotation with tolyl arsonic acid has been practiced with success.

Jan 1, 1989

Factors which cause thiourea consumption in gold-leaching systems include adsorption by gangue mineral particles, complexation with base metal ions, thermal degradation, and oxidation by air/ferric iron. Of these factors oxidation by ferric iron is the most significant factor. Of course, ferric sulfate is desired as an oxidant for the gold leaching reaction, but an excess of ferric sulfate leads to high thiourea consumption. In this regard, the rate of gold leaching by thiourea must be balanced against the rate of thiourea decomposition. It is important to note that the thiourea decomposition reaction in ferric sulfate solution is relatively slow in pure solutions and has been found to be first order with respect to both thiourea concentration and total ferric iron concentration. However, when mineral particles from gold-bearing ores or concentrates are present, the decomposition rate can become quite significant. As might be expected, the catalytic activity of mineral surfaces varies with particle composition and size. Experimental results are discussed with respect to the consumption of thiourea.

Jan 1, 1997

By P. Somasundaran, S. Venkatachalam, N. K. Khosla, K. Khosla

Froth flotation of alumina particles was studied by employing and hydrogen gas bubbles. The effect of current density was studied over a range of 0.1 to1.6 kA/m2. Compared to hydrogen, the use of oxygen bubbles at any given gas evolution rate resulted in a higher flotation recovery. The existence of an optimum current density, for each given particle size was indicated. Flotation at higher current densities resulted in better flotation kinetics, while flotation at lower current densities resulted in better Spas utilization.

Jan 1, 1996

By Jie Li, Longxiang Li, Wenbing Guo, Gaobo Zhao, Yuhang Hu

Surface subsidence caused by underground longwall mining is a very complicated process in time and space, influencing building and structures on the surface of the mining area, including houses, pipelines, and highway. The field monitoring data of surface subsidence are essential for protecting them. This study investigated the dynamic and residual subsidence characteristics of both the surface and the highway over a 730-day monitoring period on a longwall panel. Three monitoring lines (Lines 1–3) were established to monitor the subsidence process, and three stages were identified: initial stage of surface subsidence, active period of surface subsidence, and residual subsidence deformation stage. The maximum subsidence value on the highway (1,786 mm) was smaller than that on the surface (2,094 mm), and the maximum subsidence velocity on the highway (41.7–50.8 mm/day) was also lower than that on the surface (66.7 mm/day). During the residual subsidence deformation stage, both the surface and highway subsidence velocities decreased to below 0.6 mm/day. Furthermore, differences in subsidence characteristics between the surface and the highway were analyzed, with the subsidence value on the highway always being less than that on the surface, while the subsidence velocity during the residual deformation stage was not always lower. This could be attributed to the influence of dynamic loads from vehicles, which could induce additional residual subsidence on the highway. Further investigation into this phenomenon will be conducted in future research.

Jul 1, 2023

By Laurence B. James

The California Department of Water Resources is concerned with the development, distribution, and protection of the State's water resources. Geologic activities of the Department relate to planning, construction, and operation of water projects, supervision of the safety of over 900 dams under state jurisdiction, and investigation and control of ground water supply. The Department is engineering oriented, and the role of the geologist is to assist with the solution of engineering problems. Some of these problems require the integration of many talents, including not only those of geologists and engineers, but also those of economists, lawyers, seismologists, chemists, geophysicists, and hydrologists, Frequently, a task force of several disciplines will attack a problem as a team.

Jan 1, 1965

By J. C. Reid

Computer-aided lithogeochemistry was used to "prospect" for stratabound scheelite (a tungsten ore) that occurs in many Precambrian clastic and chemical rocks, northeastern Brazil; The district is a metallogenic province covering about 5000km2. Exploration bedrock lithogeo-chemistry was applied at regional, local, and mine scales to identify regional tungsten trends and dispersion halos associated with economic tungsten mineralization. Regional coarse-mesh sampling (Cu,Mo,W) in 25km2 cells "found" all major mines and significant prospects using objective and cost objective computer mapping of bedrock geochemical data. The method is efficient ; of the 3600km2 study area only 9% of the original area remained after the initial pass. Of this area, the geo- chemically highest ranked (4%) cells contained the mines and prospects. Similar computer-aided treatment was applied to Cu,Mo,W,F, and Be lithogeochemical data from several mining concessions and prospects with outcropping and subsurface W mineralization. At a local scale out-cropping W mineralization was recognized at a distance of 500m. Fracture zones through which hydrothermal solutions traveled were identified; these were related to W mineralization at a depth of 200m.

Jan 1, 1986

By N. S. Margaris

The vegetation of Mediterranean ecosystems is distinguished by its resistance to adverse environmental conditions, and that is the reason for examining the possibility of growing species of this flora in waste disposal sites (WDSs). The survival and growth of vegetation established at a waste disposal site is dependent to a large extent on the qualitative and quantitative characteristics of the material used in the final soil cover. In the Ano Liossia WDS, where extensive remediation work is under way, three areas were examined, which met certain criteria in relation to the age of the underlying waste and the existence of impermeable material in the final soil cover. Laboratory analyses have determined soil parameters and nutrient and heavy metal content. Alongside this, at all three sites a network has been installed to monitor the qualitative characteristics of the gaseous phase of the soil cover material. The results showed the existence of a soil material containing few nutrients and the prevalence of oxygen-poor conditions, accompanied by large concentrations of CH4, CO2 and H2S, at depths of up to about one meter.

Jan 1, 2002

By Peter F. Howard

The lower Middle Cambrian phosphorite deposits of the Georgina Basin shown in Figure 1 were found in the period 1966-1968 by three companies, namely, International Minerals and Chemical Corporation, Continental Oil Corporation and Broken Hill South Limited. Of these deposits the significant ones are Duchess, Sherrin Creek, D Tree, Lady Annie, Lady Jane, and Wonarah which together aggregate several billion tons reserves of phosphate. Due to the economic factors of freight costs to the coast and softening of the world market price for rock phosphate, none of them is in production, nor is any in the development stage. This paper reviews the historical background to the discovery of these deposits and then deals principally with the discovery of non-outcropping phosphorites in the Barkly Tablelands of Northern Territory by the interpretation of gamma radiation logs of abandoned water bores.

Jan 1, 1971

Significant economic deposits (> 4,000 ha) of heavy mineral sands (ilmenite, rutile and zircon) were discovered in the Atlantic Coastal Plain of Virginia and North Carolina in 1989. The majority of these lands support highly productive row crop agriculture, and the development of restoration protocols that would return these lands to agricultural use was deemed to be critical to the long-term sustainability of mining operations. Virginia Tech worked closely with all stakeholders to develop appropriate restoration protocols and to coordinate their implementation. Full-scale mining operations at the Old Hickory Project in Virginia were initiated in 1997 by Iluka Resources Inc., and restoration protocols have continued to evolve in response to a variety of economic, technical, and social issues. Return of these lands to agricultural row-crop production has been complicated by lateral variability in soil physical conditions in the reclaimed pits and limited topsoil return. Approximately 150 ha of land are in various phases of reclamation, and approximately 25 ha have been released back to landowners to date. Currently, the reclaimed pits are returned to pasture vegetation, but return to more intensive agricultural production practices may be possible as soil reconstruction procedures are improved over time.

Jan 1, 2003

By Peter J. Tarkoy

The art of predicting rock excavating machine performance has become increasingly detailed and refined. Researchers using laboratory experiments and machine manufacturers using field observations have identified and defined mechanisms of failure, rock and tool interaction, and relevant design principles affecting them. Concurrently, practitioners have developed index tests which reflect rock properties relevant to machine performance. Empirical relationships between index properties and machine performance (penetration rate, cutter consumption, and machine utilization) have been established from past experience and are currently used throughout the industry. Contractors have used such relationships for estimating throughout the world. The detail in which geological, geotechnical, test, and project data, empirical relationships, and construction experience are utilized, is limited by time constraints imposed by the bidding period. To fully utilize all available data, methods of analysis, and construction experience, a simple computer program was developed for a microcomputer costing less than $7500. As a result, 1. machine performance predictions are detailed & reliable, 2. construction alternatives may be examined, 3. anticipated conditions & performance are graphically, documented & easily comparable to those encountered, and 4. results include a listing of assumptions & results of performance analyses & a graphic performance summary.

Jan 1, 1979

By W. W. Hartley

Following a Major underground coal mine incident there followed a review of the role of mines rescue ? the Queensland Mines Rescue Brigade. It wasn?t until 2002 that the real change started to happen. The issue of geographical distance was addressed by mines rescue sub stations being located on the mines sites with parent rescue stations in a central location. The funding was by means of a levy on the mining industry with legislative standards and performance included. The previous Rescue Brigades were not well organised (central districts) and the application of recognised quality management practices within local management was lacking. The structure was based on other nations models and miners managing miners was an issue for the organisation. The reform was some what painful and the QMRS organisation will still evolve with continuous improvement. Queensland has the National Champion mines rescue team for the eighth year. QMRS is participating at the level in the industry of influencing emergency systems and training senior mine management in ?Emergency Mine Management? coaching the industry in emergency response systems. We have come a long way. We have had some success and there is always the challenge of setting the standards, those we should aspire to and the courage to influence the industry to higher goals of a safer future.

Jan 1, 2010