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By Michael Harris, David Mosch

The numerous small high grade gold and silver deposits of the Front Range Mineral Belt have been uneconomical because of the high costs of mill construction, transportation, and smeltering. Processing of these ores must be simple, cheap, with satisfactory recoveries, and be environmentally acceptable. Vat leach with direct electrolytic recovery satisfies these parameters. A battery of testing was conducted utilizing bottle and bucket tests. A five ton vat leach with direct electrolytic recovery gave excellent results while a five ton heap leach proved impractical due to channeling.

Jan 1, 1987

Petroleum exploration in the Australian arid zone has been proceeding at an ever-increasing pace, subject to financial fluctuations, since the 1960's. The impacts of petroleum exploration in the arid zone are less than they would be for corresponding operations in. e.g. a forest area: in this context, Australia is fortunate in that its major petroleum producing (and prospective) , basins are offshore or in the arid zone. In addition. the other major sources of impact in the Austrlian arid zone, namely pastoralism, tourism, and rabbits, tend to be concentrated around areas of particular conservation significance, whereas petroleum exploration is not. Despite this, the cumulative impacts of exploration are sufficient to have caused concern to government regulatory authorities and some sectors of the general public. Exploration is now subject to a range of environmental constraints with various degrees of legal enforceability. To enable exploration to continue without public opposition, the industry, and government agencies charged with regulating or supervising it, must demonstrate that the net benefits of exploration exceed net costs, including environmental costs. One particularly simple and cost-effective technique for increasing the net benefit/cost ratio of exploration is to reduce the net environmental costs by minimising and mitigating the impacts, both primary and secondary, of seismic acqisition. This is best achieved by a combination of preventive and restorative techniques: careful line positioning and low-impact (or zero) line clearance, coupled with simple rehabilitation of bladed lines. Line clearance without bulldozer blading - e.g. by rolling or simply pegging and trafficking, perhaps with tracked rather than rubber-tyred vibroseis - is one promising approach currently coming into use. Rehabilitation by grading soil banks ("windrows") back on to bladed tracks, though not yet in widespread use, has proved very successful in the limited areas where it has been applied to date.

Jan 1, 1987

By R. Kuhns

The western coast of South Africa hosts a significant diamond resource within gravels associated with paleo-shorelines, channels and transgressive lag deposits. Diamonds were transported from the Kaapvaal Craton to the coast largely during the late Cretaceous via the paleo-Orange river systems. On shore and near shore environments are underlain by Proterozoic metamorphic and granitic rocks which provide gully and pot hole-type traps associated with paleo-channels, basins, bays and beaches. Inner and mid-shelf environments are covered by diamondiferous, poorly lithified upper Cretaceous and Tertiary sediments. The upper Cretaceous gravels were reworked along the sediment-starved coast during much of the Tertiary. Reworking was mainly achieved during marine flooding events which produced lag gravels along the paleo-shorelines. This process reworked the diamonds from low-grade Cretaceous gravels and concentrated them in higher-grade Tertiary gravels.

Jan 1, 1995

By J Jones

A common problem in the mining industry is that company exploration groups operate in relative isolation to the rest of the company; resulting in poor knowledge transfer (Qureshi and Briggs, 2006) and often priority conflicts with mine geology, operations and project departments. In recognition of this problem, Newcrest created a Minerals Division responsible for stewardship and governance of mineral assets across the value chain from reconnaissance to rehabilitation. It was recognised at an early stage that effective collaboration both internally and externally would be required to improve decision making, deliver faster cycle times and improve governance.Collaboration in companies is generally associated with the introduction of new IT functions. However, modern IT-based collaboration systems and practices are relatively simplistic compared to the long-standing practices associated with collaboration and knowledge management in science and engineering disciplines such as geology and mining.The authors of this paper have started a trial of a 12-point plan for effective collaboration, which recognises that significant efficiencies can be gained and barriers to future success removed if more effective collaboration can be achieved between science and engineering divisions in a company along with external professionals and with the collective intelligence (Tapscott and Williams, 2006) of the outside world. To meet growth aspirations some companies, like Newcrest Mining Ltd, are adopting this comprehensive, step change approach by moving from a closed model the isolates mine geologists to an open and collaborative model that uses IT visualisation systems strategically. The paper describes how an open model provides people with the right work environment and the right information at the right time, which will help individuals and workgroups to work more collaboratively day-to-day. The aim is to achieve speed, focus and mitigate risk through an environment where everyone and anyone can contribute effectively (Cisco, 2008).

Aug 22, 2011

By Robert L. Lagace

The objective of this task was to perform theoretical analyses related to identifying and increasing the understanding of wireless propagation mechanisms in mines, and for predicting the performance ranges and limitations of proposed systems. This was to be achieved by building on and extending previous ADL work* and utilizing experimental data as they became available in the radio frequency bands of interest. B. TASKS Theoretical radio wave propagation investigations undertaken on this task centered on three areas. The first area dealt with extending previous UHF wireless propagation results*: to estimate the losses caused by the presence of haulage vehicles such as trains in coal mine tunnels; to estimate the propagation losses and wireless communication ranges expected along a longwall coal face tunnel; and to assess the applicability of previous analytical approximations to tunnels having reduced crossectional dimensions, such as those found in low coal and in the presence of haulage vehicles. The second area dealt with the development of a suitable propagation model to adequately explain the unexpected, highly favorable LF to MF band wireless radio wave propagation behavior experimentally observed in Consolidation Coal Co.'s Ireland mine. The third area dealt with the formulation of a model for evaluating the overall system transfer function and transmitter requirements for a hoist shaft LF communications system, taking into account the hoist rope/shaft transmission line characteristics, the cage and sheave wheel line terminations, the signal inductive couplers, and hoist shaft signal and noise data.

Jan 1, 1975

By Juan J. Monsalve, AMAN SONI, Nino Ripepi, Richard Bishop

The design and strength of pillars are important parameters when implementing the room-and-pillar mining method in a limestone mine. The process becomes complex with the presence of karst voids, which are frequent phenomena in carbonate rock formations. This research continues a previous study aimed at studying the effect of karst voids on the strength of a particular limestone pillar. Using calculated pillar strength and estimated redistributed stresses, it was assessed that the pillar can counter more stress than currently imparted on it. Numerical modeling studies combining in situ stress determination and excavation sequencing were used to estimate the existing stresses on the pillar. Different possibilities of modification to existing pillar design were simulated using distinct element method (DEM) modeling to determine a better design.

Jun 1, 2023

By A Dennis, T Hunter, R Coleman

For metallurgical plant design, it is necessary to progress through successive phases of test work, piloting and process development before involving all the other engineering disciplines and “freezing” the process design criteria and flow sheet. This process usually relies upon the experience, skills and personal preferences of various technology providers, study and engineering entities, test work and metallurgical laboratories and, most importantly, the owner’s team and its operators. Current industry trends include lower grades, more complex orebodies, geometallurgy in defining orebody variation and design envelopes, more common “hybrid” plant processes and the market demands for more reliable, timely and predictable early plant performance.This paper will discuss interaction of these trends and provide guidelines for the level of detail and technical complexity required for a number of different “typical” examples. The paper will pay particular attention to the study definition level translated into the required detail and certainty needed by the overall process “owner” and original equipment manufacturer (OEM) equipment suppliers to ensure the best real plant performance. Some recent case studies will be discussed. In many projects, at a late stage of project definition, it has become common practice to undertake a “value engineering” phase. Although it could be argued that this should be undertaken earlier, it is largely driven by an overall need to reduce capex and “optimise” the perceived “fat” built into the project during the detailed design process. This value engineering can be very counterproductive to project timing and operational performance and warrants discussion.The paper is intended to promote discussion on a topic of wide interest. The authors’ diverse backgrounds and experiences are integral to the views in this paper.CITATION:Dennis, A, Coleman, R and Hunter, T, 2017. Critical process design considerations from test work to operations, in Proceedings MetPlant 2017, pp 12–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By W. J. Bennett

WHEN Dr. Horace Fraser, your President, invited me to speak to you today I advised him in confidence that I was leaving my present positions on April 30th. In the circumstances it seemed to me that this audience might prefer to have as its speaker one who wo.uld J1ave a continuing association with the atomic energy programme. Dr. Fraser was kind enough to suggest that my re-marks might he of special interest to you, since I would be able to sum up my views on the atomic energy programme. I hope that I will not disappoint him or you on that score. I am particularly pleased that my last public appearance in my present positions should be at the Annual Convention of the C.I.M. since, as all of you know, a very important part of my work has been in the mining field. As it happens, my first public address on the subject of atomic energy and its raw material -uranium -was made at your Annual Convention in Montreal in April, 1949. It seems fitting that my final address should also be made at this convention -nine years later.

Jan 1, 1958

"Accelerated expansion of Western Canada's metallurgical coal industry has again stimulated considerable exploration activity in the Rocky Mountain Foothills Belt and influenced much of the R&D related to transportation, processing and carbonization. Preparation R&D has included further pilot-plant work on desulphurization, spherical agglomeration and modified compound cyclones (which are also proving themselves in other mineral beneficiation studies). Combustion research, aside from increasingly stressing control of combustion source pollution, has directed special attention to lignite PF firing and problems arising from lignite ash. Studies directed toward the non-fuel utilization of coal have centered on such diverse topics as active carbons, carbonaceous filter media, plant nutrients and industrial applications of humic acid derivatives. In addition, a number of long-range research projects related to such matters as coal chemistry and pyrolysis have been actively pursued, and further attention has been given to improved sampling techniques and analytical methods."

Jan 1, 1969

By S. James Campbell

Ladies and Gentlemen: Never in the history of our mining industry has the emphasis on public relations been accelerated as much as it has in the last few years. Knowing of your keen interest in this subject I consider it a great privilege that your program committee has asked me here to discuss the crushed stone segment of our industry approach to this important part of our daily business lives. As you are aware, crushed stone operations are present in almost every segment of the country wherever aggregates for construction projects are required. The tonnage of crushed stone produced is second only to sand and gravel - another source of aggregates - and this together with sand and gravel amounts to over half of the tonnage of all mined products in the United States. What is unique about this industry that will be of interest to all of you in analyzing how they have approached Public Relations? The fact that it is so wide-spread is of course obvious, but perhaps a more significant nature of this segment of the mining industry that has brought it more in the limelight of public interest and on a larger scale is the location of a large part of the quarries quite close into the urban area and population centers where you have the greatest demand for aggregate products.

Jan 1, 1969

By Abbas Zaidi, Betty L. W. Ou

Wastewaters generated during the extraction of gold from the ore can contain a variety of contaminants such as cyanide, heavy metals and arsenic. Proper management of these wastewaters is therefore necessary to minimize the negative impact of gold mining and milling operations on the environment. The Wastewater Technology Centre (WTC),located in Burlington, Ontario, Canada, has been involved in several studies related to the evaluation of various effluent treatment technologies which are relevant to the treatment and proper management of gold mill effluents. These studies have included bench and pilot scale tests, and the evaluation offull-scale systems. Furthermore, the WTC staff developed protocols for cyanide analysis in gold mill effluents, and a mathematical model for predicting the degradation of cyanide in tailings ponds. The information generated by the WTC staff has been referenced in several reports and papers published over the last ten years (Schmidt et.al. 1982, Simovic & Snodgrass 1989, Whittle et.al. 1989, Zaidi et.al. 1989, Zaidi et.al. 1991). Recently, the WTC has started to develop a micro­computer based expert system for use by decision makers in the gold mining industry and relevant government agencies who are involved in process design, process evaluation, costing, evaluation of the best practicable technology, approval of suggested effluent management systems, and so on. This paper presents some relevant background information and a discussion of the latest version of the expert system being developed by the WTC.

Jan 1, 1992

By Cody Giroux, Homer Scurlock, Michel Wasag

Silica and Crystalline Quartz exposure continues to be a serious health threat to nearly 2 million workers in the United States, including more than 100,000 working in high risk jobs such as abrasive blasting, foundry work, stonecutting, rock drilling, quarry work, mining and tunneling. The primary focus of this study is to identify the best methodology to reduce particulate-laden air and limit/eliminate exposure to respirable dust with silica/crystalline quartz during tunneling operations. This study focuses on two de-dusting systems employed on similar tunnel construction projects. The first project is the Coxwell Bypass Tunnel located in Toronto, Ontario Canada. The second project is the Westerly Storage Tunnel located in Cleveland, Ohio. The Toronto project is utilizing a wet de-dusting system. The Cleveland project is using a dry de-dusting system. The objective is to determine which system provides the best protection and suitability to capture, remove and ultimately reduce respirable concentrations of silica/ crystalline quartz to safety and healthy levels in underground tunneling activities.

Jun 13, 2021

By J. W. Thompson

The term "minerals" when employed in a conveyance in the State of West Virginia is understood to include every inorganic substance which can be extracted from the earth for profit, whether it be solid, as rock, fire clay, the various metals and coal, or liquid, such as salt, and other mineral waters and petroleum oil and gas. Horse Creek Land & Mining Co. v. Midkiff (West Virginia), 95 Southeastern 26, p. 27. TERM INCLUDES OIL AND OAS. The term "minerals" used to describe the interest in land granted or reserved bona fide includes petroleum oil and natural gas. Horse Creek Land & Mining Co. v. Midkiff (West Virginia), 95 Southeastern 26, p. 27. INJUNCTION TO PREVENT RElllOVAL. The removal of ore from the premises of another without his consent will be enjoined. Barnes v. Esch (Oregon), 169 Pacific, 512, p. 518. TITLE TO MEXICAN BULLION-JURISDICTION OF FEDERAL COURTS TO DETERMINE. Where bullion within the jurisdiction of the Mexican Government was seized, condemned, and sold for war supplies by the Constitutionalist forces in the revolution acting under authority from Gen. Carranza, claiming to be the provisional President of the Republic of Mexico, a United States district court of Texas, into which State the bullion has been imported from Mexico, has jurisdiction to try and adjudge as to the validity of the title acquired by and through the seizure, appropriation, and sale by the Carranza forces as against an American citizen claiming ownership of such bullion prior to its seizure.

Jan 1, 1919

By J St George

Much of AucklandÆs transport infrastructure has been developed on surface with little or no consideration of underground options. Current and planned transportation routes are now facing high costs due to land values and increasing environmental resistance to surface development. The option of utilising underground space becomes a feasible investment decision for these links as well as being the only option to develop the rail network within the inner city area. Transportation tunnels offer a quieter, more energy efficient means of getting around with minimal impacts on the surface environment. One of the major impediments to tunnelling is the high construction cost, which is partly related to the risks of encountering unexpected ground conditions and/or the possibility of causing surface ground deformations which could damage structures. The geology of Auckland has had substantial investigation through various studies and projects. The sediments of the East Coast Bays Formation (ECBF) underlie most of the Auckland urban area. It is classified as a soft rock and is a suitable material to tunnel through using either a tunnel boring machine or a roadheader. This paper reviews the limited amount of tunnelling completed in the urban Auckland area, together with the international advancements that have been made in the tunnelling industry. From the known features of the local geology and the problems encountered historically, the likely risks of tunnelling in Auckland are presented and ways in which those risks could be reduced and managed, are discussed. In addition, contractual arrangements between client and contractor are assessed with respect to complicated projects (such as tunnelling), so that the risks can be managed to create efficient infrastructure routes with reduced costs.

Jan 1, 2008

By D. M. Conner

An innovative patented process has been developed to convert high volume wastes--fly ash from coal-fired power plants, municipal solid waste (MSW) ash from incineration, solids from waste water treatment and paper mill sludge into a high value and environmentally benign product in the form of a lightweight aggregate. Lightweight Aggregate is widely used in the building construction industry in the United States, Europe and some Asian countries. This paper will present the development of the process, the process itself and details on the first commercial scale plant. The commercial plant is owned and operated by Wisconsin Electric Power (WEPCO).

Jan 1, 1997

By M. I. Mabala, B. P. Watson, M. J. Kanda

A failed and stable Upper Group 2 chromitite pillar database was collected in 2007 as part of the PlatMine 1.2 pillar strength project. The database consisted of 177 pillars, of which 33 had failed. Most of the data were collected from various intermediate-depth mines near the town of Thabazimbi. Spans between rows of chain pillars were about 30 m. Pillar loads were estimated using pseudo-3D, elastic, boundary element modelling software. The pillar-load data were evaluated using a maximum likelihood regression analysis to determine strength parameters, following a similar approach to historically acceptable practice. The original formula was named the PlatMine Formula. This paper describes re-evaluations of the database, using a linear formula and several variations of the power formula. The formula providing the lowest standard deviation to the data in the database was considered the best representation of the pillars in the database. Through this rigorous process, a new formula for peak pillar strength was developed for Upper Group 2 chromitite pillars, which is unaffected by volume. The small standard deviation provided by this formula suggests a reliable relationship between strength and w/h ratio, in the w/h ratio range between 1.5 and 4.7. Accuracy, precision, and recall analysis confirmed the efficacy of this equation to the data in the database. Importantly, the new formula provided in the paper does not predict a significantly different strength to the current PlatMine formula, within the confines of the database.

Nov 27, 2024

By Michaela Dina Stanescu, Emilia Visileanu, Eftalea Carpus

"The recovery and reintroduction into the economic circuit of the textile material resources must be considered as component parts of the strategies of harmonizing the relationships between the economic growth, consumption of natural resources and environmental protection of the existing socio-economic system.The waste recovery for ensuring a sustainable development is a major concern of all industrial researches. In the textile domain, the concern in this matter is becoming more evident. An important role in manufacturing textile products it has the notion of eco-design, which has grown considerably over the last twenty years with increasing awareness of environmental and social problems in the industry.Introduction“Humanity must learn from the global financial and economic crisis experience""- is the conclusion of the policy makers who should develop a strategy designed to reinvigorate the economy and make possible an"" intelligent, sustainable and favourable to inclusion” growth, by a better coordination of national and European policies.The new vision for social market economy is based on three priority areas: smart economic growth, the development of an economy based on knowledge and innovation; sustainable economic growth, the promotion of a competitive economy with low carbon emissions and an efficient use of resources, as well as an inclusive economic growth, the promotion of an economy with high degree labour employment, which would generate social cohesion. The recovery and reintroduction into the economic circuit of the textile material resources must be considered as component parts of the strategies of harmonizing the relationships between the economic growth, consumption of natural resources and environmental protection of the existing socio-economic system.The waste recovery for ensuring a sustainable development is a major concern of all industrial researches. In the textile domain, the concern in this matter is becoming more evident. It is obvious that at the origin of pollution there are the technological processes of textile processing with impact on air, water, soil, as well as the storage processes. In all phases of obtaining a product, a series of secondary products and textile wastes with impact on the environment occur. The product used becomes also a factor of environmental pollution, which in most cases fails to assimilate."

Jan 1, 2012

By A. Panteleyev, C. S. Ney, R. J. Cathro, A. Sutherland Brown

The general distribution of metal deposits in the Canadian Cordillera can be related to its tectonic evolution. The Canadian Cordillera is naturally divisible into five longitudinal tectonic belts within which rocks are broadly similar in type, age and history. From west to east they are the Insular, Coast Crystalline, Intermontane, Omineca and Eastern Marginal belts. Seven classes of metal deposits in the Canadian Cordillera are defined and their characteristics described. These classes are skarn, porphyry, massive sulphide, stratiform, magmatic, copper in basic lavas, and vein deposits. Maps showing the distribution of medal and metal-group concentrations serve to illustrate the relations in space and time between mineralization and geologic evolution.

Jan 1, 1971

By R. R. Sayers

Under compuision of the present urgency to implement the President's promise to make the United States the arsenal for the democracies there is a tendency to demand a relaxation of restrictions on hours of labor and to speed up all industrial processes. The pressure is the more insistent with growing realization of the importance of the time factor in the success- ful prosecution of the war effort and the lack of skilled workers due to (2) operation of the draft, lack of an apprentice system in industry, and loss of skill by workers unemployed for long periods during the depression. With "total" war such as it is today the probabilities are that everyone will be required to exert greater effort (in many instances in activities to which they are unaccustomed) for longer periods than ever before has been necessary. The question arises, "What will be the aftereffects as well as the immediate effects on health, safety, and efficiency?" A review of the literature leaves the impression that this question has not been an- swered completely, especially as regards the ultimate effects. Mechanization, speeding up of industrial processes, mass produc- tion, and the small industrial concerns present many problems to indus- trial medicine. Does the tendency to expect the worker to produce at full speed all the time he is on the job decrease the effectiveness of the shorter working hours and cause undue fatigue, loss of efficiency, and increased accident proneness? The answer is important as this condition is likely to be intensified by the exigencies of the present emergency. According to Viteles (1)3, The increased tension under such conditions of work appears to offset the savings in muscular force made pos- sible by the machine. The tension, the speed, the subject- tion to specialization of work and a rhythm uncontrolled by the individual promote fatigue, characterized by a "decrease in the power to work, a decrease in pleasure taken in work, and a decrease in the enjoyment of the hours spent away from work."' The crowding of workers in temporary structures without proper provision for comfort and health may add greatly to the general fatigue factors already present in many industrial establishments. In 1932 Lockhart (2) stated that the production and maintenance of a healthy, satisfied industrial population is the most urgent necessity, involving problems so serious as to constitute a national task too great economically to be relegated to industrial concerns. If this was true in 1932, it must be doubly so today.

Jun 1, 1942

By A G. Tomkins

"Approximately 32 per cent of the worldÆs total gold production has come from greenstone belts (Frimmel, 2008). In these regions numerous small to large, quartz vein-associated gold deposits are hosted in metamorphic rocks ranging from lower greenschist to granulite facies. Historical exploration has focused its efforts on rocks of greenschist to lower amphibolite facies because these seem to contain the most deposits. Consequently, these regions are now reaching mature brownfield status, particularly in developed nations, and finding new deposits is becoming progressively more difficult. In comparison, regions of similar tectonic setting, but instead containing high-grade metamorphic rocks of mid-amphibolite to granulite facies, have received little attention because the first explorers found fewer deposits there.However, these regions certainly do contain some very significant gold deposits such as Hemlo in Canada (~684 t Au), Renco in Zimbabwe (~31 t Au mined since 1980), the very profitable Challenger deposit in South Australia (~36 t Au; recovered + reserve + resource), and the most recently discovered Tropicana deposit in Western Australia (~182 t Au; reserve + resource). High-grade metamorphic terrains therefore offer explorationists an excellent opportunity to move onto relatively green fields within developed nations, which carry less risk associated with development. However, explorationists have comparatively little knowledge of the geological controls on gold distribution in high-grade terranes because: industry experience lies in traditional lode-style gold deposits these gold deposits are geologically more complex there has simply been minimal research conducted on these deposits as a holistic group.Furthermore, research conducted in the last five years has shown us that the previous widely accepted model for gold genesis in these terranes, the crustal continuum model, is incorrect. Here, I discuss features from several gold deposits hosted in high-grade metamorphic rocks and use these to define two categories for explorationists to consider: deposits that formed prior to peak metamorphism (metamorphosed gold deposits) deposits that formed well after peak metamorphism (post-metamorphic gold deposits). There are none that have been convincingly shown to have formed during peak metamorphism.CITATION:Tomkins, A G, 2013. Gold deposits in highly metamorphosed terranes, in Proceedings World Gold 2013, pp 23-26 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 26, 2013