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By Clayton A. Signor

Abstract: Expansive soils cause more damage to structures annually than a combination of other major natural disasters. Because of the cost to our society, all means and methods need to be fully explored to mitigate the problems associated with expansive soils. This study will present a foundation design approach that is underutilized in this application, driven piles. The main objective of the study is to present pile test results and analysis from four driven pile project sites in three types of expansive soils found in central Texas: Del Rio formation, Taylor/Navarro formation, and expansive alluvium. High strain dynamic pile tests were conducted on each of the four studies with rigorous signal matching analysis from the CAse Pile Wave Analysis Program (CAPWAP). Ultimate pile capacities ranged from 73 to 311 kips with an average of 61% of the total capacity coming from the pile shaft and were two to six times the structural capacity needed. Allowable loads calculated from Modified Gates dynamic formula best modeled allowable test results. Average unit skin frictions ranged from 0.50 to 4.71 ksf. Restrike pile tests of 1 to 17 days after initial driving reported 30 to 100% shaft capacity gain. All open-ended pipe piles driven produced soil plugs ranging from 4 to 14 feet thick. Small diameter, thick-walled, open-ended pipe piles reached penetration of twice the depth of designated zone of seasonal moisture change without problem. The observed production rate of the driven piles was on average 8 minutes, which implied daily production of 15 to 40 piles. Predrills or augered holes should be specified for underground obstructions found in soil investigation.

By R Dimitrakopoulos, R Goodfellow

One of the primary objectives when optimising a mining complex is to maximise its value for the primary stakeholders. In order to achieve this objective, it is necessary to holistically optimise all aspects of the mining complex, including decisions of when to extract materials from the available sources, how to blend or stockpile these materials and how to best use the available processing streams to satisfy customer demand. Existing methods for global, or holistic, optimisation ignore the compounded effects that risk has on the performance of a mining complex. Over the past decade, several stochastic optimisation approaches have been proposed to integrate various forms of uncertainty into the open pit mine design and production scheduling. These methods, however, are limited in their ability to simultaneously optimise the production schedules for the portfolio of mines, material destination policies, the use of the available processing streams and the various products that are produced at each location of the mining complex.This paper aims to discuss a new method for the global optimisation of open pit mining complexes with geological uncertainty. The proposed generalised methodology is capable of modelling and holistically optimising mining complexes, including aspects related to production scheduling, blending, stockpiling and non-linear interactions that often occur in practice, but are over-simplified in existing models. Two case studies are discussed to highlight the need for these complex, stochastic optimisers. First, a case study for a nickel laterite blending operation highlights the need to integrate geological uncertainty into the optimisation in order to ensure product quality constraints are respected. Second, a case study for a copper-gold mining complex highlights the added value when simultaneously optimising the production schedule and the stockpiling and treatment of extracted materials.CITATION:Goodfellow, R and Dimitrakopoulos, R, 2014. Stochastic optimisation of mineral value chains – developments and applications for the global optimisation of mining complexes with uncertainty, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 13–22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By O. H. Metzger

This is the second of two papers dealing with the construction and use of aerial tramways in the metal-mining industry. The first paper3/described aerial tramways in a general way and discussed the engineering principles used in tramway design. The purpose of this paper is to give a more detailed description of equipment and material rind to discuss construction and operating costs. ACKNOWLEDGMENTS The paper is based largely on data from actual operations. Metal-mine operators from many parts of the United States, Canada, Alaska, and Mexico contributed liberally.

Jan 1, 1940

By H. V. S. Tingley

My topic today is future trends in compensation for the mining industry. I seldom get the chance to speak about a subject of such immediate interest to an audience, so I would like to make the most of this opportunity by telling you that everybody in this room will become rich beyond his wildest dreams in the next few years. I would like to open my talk that way, but in compensation, like everything else, there is a great gap between dreams and reality. Back to reality. When we talk about compensation, we?d better define our terms because the compensation is really an umbrella for five basic types of payment made to management personnel. Slide 1 identifies these elements of compensation.

Jan 1, 1980

The Graham Farmer Freeway Project in Perth, Western Australia, is the largest urban infrastructure project ever carried out in the State. At a project cost of over $360 million, it also ranks as one of the largest in Australia and is even large by world class standards. The project provides a much needed east-west freeway bypass around the CBD of Perth, linking the Great Eastern Highway in the east with the Kwinana and Mitchell Freeway system in the west. The Bypass will have 6.5 kilometres of freeway, a major bridge over the Swan River, several pedestrian overpasses and underpasses, dual use paths, interchanges and flyover bridges and a rail tunnel. The whole project is being carried out over a four-year time frame, due to be complete and open to traffic in June 2000. The project has been divided into two stages, with Stage 1 including the 1.63 kilometre long Northbridge Tunnel, the subject of this paper.

Jan 1, 1999

By John C. Machisak

INJURY and employment figures for nonmetal mines and mills in 1959 are presented in this publication. Data for nonmetal mines are presented separately from those for nonmetal mills. The Bureau of Mines is authorized to send questionnaires to the nonmetal mining industry each year requesting their voluntary submission of injury experience and employment data. The voluntary response to these requests has contributed greatly toward the promotion of safety in the industry, and every effort has been made to make the information as complete as possible.

Jan 1, 1963

By O. Babak, J. G. Manchuk

ABSTRACT A significant factor in evaluating bitumen recovery from an oil sands mine is the particle size distribution (PSD). Increased understanding of mined ore quality and improvement in predictions of recovery can be achieved through PSD modeling. This paper addresses PSD modeling using geostatistics. PSDs may be described using many discrete particle sizes, making this a challenge. The approach parameterizes PSDs with a few statistics. A lookup table is used to reconstruct the PSDs based on models of the statistics. The workflow is applied to Total E&P Canada’s Joslyn Lease and yields good results that reproduce input statistics without introducing artifacts.

Jan 1, 2013

By Paul R. Weber

Open-pit mines are constructed in materials characterized by the complete range of geologic materials from the most recent alluvial sediments to hard intact crystalline rock. The determination of stable slopes in recent alluvium is in the realm of soil mechanics, an established engineering discipline, well founded on theoretical development and years of substantiating experience. The analytical tools of the soils engineer are chiefly derived from continuum mechanics wherein load-deformation response is governed by mass properties of the substance. At the other end of the spectrum, slopes in hard unweathered rock can generally be analyzed in a straightforward manner by the methods of discontinuum mechanics wherein the properties and orientations of joints control the response of the material. This approach is exemplified by the classical work of Terzaghi (1962). In between these two extremes is a gray area of material types which are composed of stiff soil and incompetent rock. This area is of importance to the mining engineer, since a large portion of open-pit mines is excavated wholly or in part into incompetent rock. This paper describes an approach to pit slope design in incompetent rock in which the material behaves essentially as a continuum. A wide range of geologic materials from stiff soil to poorly indurated sandstone and shale to crushed or weathered crystalline rock appear to fit in this category. These materials all possess certain mechanical properties which must be accounted for in a realistic assessment of slope stability. These properties include nonlinearity, s tress -dependency, and inelasticity. Further considerations involve residual stresses and time-dependent seepage pressures where groundwa.ter is present.

Jan 1, 1971

By Sherwin F. Kelly

THIS is intended as a simple review of the principles and practice of geophysics, so will not be of interest to the geophysicist, who is hereby warned of its elementary character. The engineers for whom it is written are those who, having glimpsed the formidable formulas and discussions of the geophysicists, give all publications on the subject a wide berth. For a few years now the geo-physicists have had a tendency to be ingrowing at their meetings, going deeper and deeper into theory and instrument construction, and forgetting to present the topics that would interest the practicing engineer who desires merely to know how geophysics can help him, not why.

Jan 1, 1934

By LeRoy D. Loy

To facilitate effective land reclamation and comply with existing state regulations, surface coal mine operators have in recent years adopted new mining techniques and equipment utilization for steep-terrain mining. In contrast to direct spoiling with draglines or shovels, these new mining methods require some form of overburden haulage from the excavation face to the point of reclamation. Although current mining methodologies such as Block-Cut, Modified Block-Cut, and Mountaintop Removal with Head-of-Hollow Fills have proven effective in achieving reclamation objectives, some production problems have resulted from pit congestion and excessive equipment delays. Recognizing this problem, the United States Bureau of Mines contracted Skelly and Loy to design innovative mining concepts utilizing conveyor haulage in place of trucks, loaders, dozers and scrapers. Project objectives required definition of current bottlenecks and development of mining systems to: alleviate bottlenecks; increase production potential; facilitate additional resource recovery; enhance reclamation; reduce safety hazards; and improve mining economics. Successful completion of project goals within a four year program involves systematic implementation of the following separate work phases: 1) Develop Concepts for Block-Cut Mining Systems; 2) Determine the Economic and Technical Feasibility of Concepts; 3) Prepare Detailed Design and Specifications of Concepts; and 4) Prepare Specifications for Conducting Field Tests of the Most Promising Concepts. At the time of this publication, Phases 1 and 2 are finalized with Phase 3 efforts well underway.

Jan 1, 1977

By Roberto Carneiro da Silva, José Geraldo da Silva Moreira, Eder Quental de Araújo, Patrick Petronio de Castro Andrade

Os fornos de reaquecimento são equipamentos comumente utilizados na indústria siderúrgica para aquecimento de produtos intermediários produzidos pelo processo de lingotamento. A operação correta desses equipamentos pode ser medida através de sua produtividade, seu consumo específico e seu rendimento metálico. Isso se torna ainda mais desafiante quando se trata de fornos multicombustível, e de uma siderúrgica integrada de grande porte como é o caso da Gerdau Ouro Branco, que possui 5 fornos de reaquecimento para atender a 5 diferentes laminações onde a disponibilidade de gases combustíveis é variável para cada forno. Dessa forma, esse trabalho traz uma metodologia de otimização capaz de determinar qual a melhor mistura de combustíveis e Poder Calorífico Inferior do Gás Misto (PCIGM) para operar os fornos de reaquecimento em diferentes situações e necessidades operacionais e de produção.

Aug 1, 2019

By J-P Franzidis

Mill operators have traditionally been forced to rely on grade-recovery curves and overall flotation rate constants when analysing proposed improvements to plants. This has led to loss in money and time when a proposed change that showed potential in laboratory scale tests failed to show improvement in the plant. Frequently, this is a result of the operators being unable to gain insight into how and why the proposed change affected the flotation performance. This is due to the classical models not including any description of the subprocesses of flotation and their individual contribution to the overall flotation performance. A new flotation model has been developed as part of the AMIRA P9 project that separates the flotation process into subprocesses and includes the contribution of both the pulp phase and froth phase to the overall flotation recovery. It is not possible to determine the individual components of this new model on traditional pilot plants as they lack the required flexibility and scale. Therefore a new pilot plant has been developed known as the Floatability Characterisation Test Rig (FCTR) that has the flexibility and features required for the determination of the flotation subprocesses. The flexibility and features of the FCTR also make it an ideal tool for investigations into many different aspects of flotation research. These include the effect of reagents, grinding, and power on the flotation performance. This paper will describe the methodology for using the FCTR in these fields of research and highlights the advantages of using the FCTR over traditional methods.

Jan 1, 2000

By Gordon W. Hines

This paper, dealing with network planning in an industrial complex, discusses the type and size of project that can be handled on a manual basis. After a review of the fundamentals of network planning, and specifically of the Critical Path Method, the author analyses several different types of projects, each with its own characteristics. Some can be handled in conjunction with a computer, but others can be dealt with equally well without one. Among the projects discussed are a blast furnace reline, the installation of a billet mill flying shear, and routine maintenance-type operations.

Jan 1, 1967

By C Mpodozis

Central Andean (22¦S to 34¦S latitude) Miocene giant ore deposits share common features that reveal their origin. Tectonic and magmatic features include a relation to a shallow subduction zone, an association with the waning or initiation of a magmatic episode, emplacement at the time of uplift associated with crustal thickening and formation at times of major magmatic changes along the Andean margin. Rare Earth Element (REE) signatures in magmas erupted near the time of mineralisation indicate a progressive change from equilibration at depth with a hydrous, intermediate-pressure amphibole-bearing mineral residue to equilibration with an anhydrous high-pressure garnet-bearing assemblage. These features point to a common history. First, a relatively shallow subduction zone leads to hydration of a cool mantle wedge providing a source of fluids which builds up over at least several million years. Arc magmas formed at this time equilibrate with a hornblende-bearing residual mineralogy. Second, a compressive tectonic regime leads to crustal shortening and thickening that facilitates entrapment of arc magmas in the crust. Eventually, the magma-weakened crust yields to horizontal compression causing rapid crustal thickening. Fluids required for mineralisation are liberated as amphibole-bearing assemblages break down to garnet-bearing ones and over pressured fluids are released from plutons. Mineralisation subsequently ceases in the region unless continued dehydration of the slab and mechanical thinning of the continental lithosphere causes the previous conditions to repeat. The type of mineral deposit generated depends on the pre-existing continental lithosphere and the distance from the trench.

Jan 1, 1999

By M. M. Barr

Rapid expansion of the titanium-metal industry focused attention upon ilmenite as a possible substitute for the more expensive and less abundant rutile in producing titanium tetrachloride. Most of the rutile available for this use is imported. Preliminary studies were undertaken to determine the chlorination characteristics of high-titanium slags produced by electric-arc furnace smelting of alluvial Idaho ilmenite at the Federal Bureau of Mines Northwest Electrodevelopment Experiment Station, Albany, Oreg. Low silicon, calcium, and aluminum contents of the slags enhanced their potential value for chlorination.

Jan 1, 1958

By A. C. Fieldner

In 1927 the Carbonization Committee of the American Gas Association proposed cooperation with the Bureau of Mines in the development of suitable methods for determining the carbonizing properties of American coals. It was further proposed to apply these methods in the testing of representative coals and to make the information obtained available to the public through Government publications. A cooperative agreement was signed whereby the Gas Association contributed part of the funds necessary for beginning the project and appointed a committee to consult and advise the Bureau in the work. The Advisory Committee has been reappointed each year, and the Bureau has had the benefit of its advice. The composition and carbonizing properties of 33 coals previously tested have been given in technical papers of the Bureau of Mines and in short reports published for the most part in the Proceedings of the American Gas Association. A complete list of publications on the work previous to 1937 is appended to this report. The present report gives the composition and carbonizing properties of seven additional coals from West Virginia. The data include results of blending tests in which Beckley led low-volatile coal was used with all the high-volatile coals except the Alma coal, with which Pocahontas No. 4 coal was used.

Jan 1, 1938

By L. E. Cardwell

This publication contains routine analyses and related source data for 475 natural gas samples from 17 States and two foreign countries. Of this total, 454 samples were collected during calendar year 1971. The remaining 21 samples were collected during previous years, but releases granting permission to publish the analyses were not received until 1971. All samples were collected as part of a continuous survey of the free world for occurrences of helium in natural gas. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4863 and 576.4 Thirteen previous publications have presented the results of 9,427 gas analyses prior to 1971. The first three, Bulletins 486,5 576,6 and 617,7 contain analyses and related source data on 5,218 gas samples collected from

Jan 1, 1972

By G Lane, S La Brooy

A century ago, new mines were often accompanied by smelters. In Australia, smelters were built at the Daydream mine near Broken Hill, at Kuridala and Mount Elliott near Mount Isa, Broken Hill, Mount Lyell, Mount Morgan, Mount Isa, and more recently at Tennant Creek, Kalgoorlie and Olympic Dam. Now the big miners eschew site-based processing in favour of shipping concentrate to smelters in Europe and Asia. As Chip Goodyear was in the process of vacating his leadership role at BHP Billiton, he was quoted as saying that BHP should concentrate on mining ore and leave æto others the skill set of processing that materialÆ. Yet there are times when on-site processing clearly makes sense. Few companies ship gold ore or concentrate to China for gold extraction. New smelters are being built in Zambia. Solvent-extraction and electrowinning plants frequently produce copper from oxide ores and concentrates while pressure leaching is increasingly being considered for copper sulfide ores. Some argue that on-site processing is best because the waste products can be returned to the ground from whence they came, avoiding potentially large disposal costs in more-populated areas. Copper treatment and refining charges will not remain at $45 per tonne and 4.5 cents per pound forever. This paper examines when it makes sense to use on-site pyro- or hydrometallurgical processes in todayÆs environment and comments on how current trends might alter the balance in future.

Jan 1, 2008

Greater automation of facilities is probably the best hope of the mining industry in its efforts to surmount continually rising labor costs. Underground mining, with its inherently low unit labor output, is especially vulnerable to rising costs, and here maximum automation is becoming increasingly important. One area of such operations that has been receiving a great deal of investigation is that of ore haulage and hoisting, two steps that often account for 10-35% of underground operating costs. Innovations and experimentation by mining firms and manufacturers over the past few years have resulted in larger, faster and more efficient tramming and hoisting equipment, but the White Pine Copper Co., at its operation in the Upper Peninsula of Michigan, is preparing to start up an entirely new concept in haulage later this summer. Known as the Dashaveyor System, it consists of individually powered modules (cars) that run on tracks inside a rectangular tube or on an open trackway at predetermined speeds up to 50 mph. At White Pine the Dashaveyor will be used to carry ore (crushed underground to -10 in.) from the mine to the concentrator. Dr. James Boyd, president of Copper Range Co., which is a 25% shareholder in The Dashaveyor Co., has indicated that if the Dashaveyor meets the expectations for surface operation, it will also be used underground for ore transport in place of the several miles of conveyor belts currently in use (Business Week, July 29, 1967).

Jan 7, 1968

The flotation of nickel sulphide minerals is normally difficult in the presence of serpentine minerals due to the coating of serpentine particles on the nickel mineral surface. To improve the flotation, dispersants such as polyphosphate and carboxy methyl cellulose are normally used to remove the slime coating. However, in the flotation using high ionic strength process water, these dispersants are invalid due to their ionic nature. In this study, a new type of non-ionic dispersants, Pluronic triblock copolymers were examined with an objective of improving the flotation of ultrafine pentlandite (a nickel sulphide mineral) in the presence of lizardite (a serpentine mineral) in saline water. Three Pluronic triblock copolymers varying in solubility and hydrophile-lipophile balance (HLB) values were studied by flotation tests, settling tests and froth measurement. It was found that two of the copolymers improved pentlandite flotation against lizardite, and one copolymer deteriorated the flotation. The effect of Pluronic triblock copolymers on the flotation was actually linked to their dispersibility and foamability, which were governed by their physical properties. The two copolymers with a higher solubility or HLB value produced more stable mineral suspensions and more stable froth in the flotation resulting in better nickel grade and recovery in both rougher and cleaner flotation. Keywords: ultrafine particle, flotation, slime coating, dispersion, saline water, triblock copolymers

Sep 1, 2012