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By John K. Hammes

This paper has been written as one of a group of papers dealing with the subject "Cost Elements in Mining". What are cost elements in mining? The mine operator thinks of direct mining costs in terms of labor, materials, supplies and power, and we might define cost more generally as the price paid to acquire or produce something. Economic theory also has its concepts of cost. From one point of view, that of the consumer, the cost of mineral commodities might be viewed as the total price industry pays for mine output. Similarly, the mining company engaged in the on-going business of finding, developing and operating new mines is concerned very much today with the distribution of all the revenue paid for mine output and not just with its direct or controllable cash costs. In other words, what will the labor force, the supplier of energy, explosives, and reagents, and the supplier of government services, management, capital and the ore reserves receive for their contribution to production.

Jan 1, 1974

By Charles Vaught

The U.S. Bureau of Mines evaluated the self-contained self-rescuer (SCSR) donning proficiency of 243 miners. These workers were from eight underground coal mines in the eastern United States. The objectives of the study were (1) to gather information on skill levels, since all miners in the study had prior instruction and opportunity to practice donning the apparatus, and (2) to summarize a quality control procedure useful in conducting periodic evaluations of donning proficiency. The sampling procedure used proved to be both reasonable and efficient in gathering information on training effectiveness_ It also provided a good statistical base for making informed site-specific decisions regarding SCSR training needs. Results from the observed samples at each of the eight mines indicate a wide variability across sites. The rate at which miners failed to isolate their lungs varied from 33 to 40.0 pct. Concomitantly, proficiency rates (miners either performing adequately or demonstrating a perfect 3+3 sequence) ranged from 13.3 to 63.3 pct.

Jan 1, 1991

By AIME AIME

STEADY advance has been made in the art of lead smelting and refining during the year. The bringing of natural gas to the Salt Lake valley has led to its adaptation to lead smelting operations. The Tooele plant of the Anaconda Copper Mining Co. has put into practice the high blast pressure and constant volume for lead blast furnaces, which we understand was first advanced by John F. Austin. It would appear that within limits, capacity is nearly proportional to the volume of air. If the charge is dense, a constant pressure, as in the old practice. did not get much air through the charge and the furnace slowed up. The constant volume idea makes the charge smelt at the same rate as if the charge were porous. The cost of a little additional power insures capacity operation at all times.

Jan 1, 1932

By Yanske TR, Lane WL

The Doc Run Company and its predecessors have been mining for over 130 years utilising the room and pillar mining method. This method has left approximately 20 per cent of the orebody in the remaining pillars. The original design and planning for the mines did not include extensive pillar extraction. This paper summarises the introduction of the pillar extraction and backfill techniques which have been implemented since 1991. These techniques include the use of low cost fill walls up to 20 in in height and the use of stinger trucks for topping off the fill. In conjunction with these accomplishments, much experience and confidence has been gained in the use of numerical modelling as a method of predicting pillar stability as the mining of pillars progresses. These advances have led to pillar extraction hecoming a major portion of the overall production and have added to the mine life of Doe Run's six operating mines.

Jan 1, 1998

By J. Pohlig

It is with more than ordinary pleasure that I have complied with the request of the President of the Verein Deutscher Eisenh?tten leute, to read before this meeting and in this country a paper on a system of transport by wire ropeways which, during the past twenty years, has advanced with rapid strides in Europe, and more partic ularly in Germany. America, with its immense network of railways and water communications, should offer peculiarly favorable oppor tunities for the introduction of these ropeways as feeders, more par ticularly in the mining districts, where, as in Europe, a hilly or mountainous region frequently opposes serious obstacles to the em ployment of surface railroads. The importance of the aerial ropeway as a factor in the develop ment of mineral resources deserves the consideration of every mining engineer. As a case in point, the rich iron-ore of the sierra de Bedar in southern Spain, would probably remain untouched to this day but for an aerial ropeway, 15.6 km. (9 3/4 miles) long, which con nects the mines with the shore of the Mediterranean near the town of Garrucha, affording cheap carriage to the nearest shipping point. A railway would have cost about $480,000 (£100,000), but such a heavy outlay would have more than absorbed all prospective profits on the sale of ore. As the aërial ropeway could be built for a little more than one-fourth of that amount, or $124,800 (£26,000), its erection furnished the successful solution of a profitable mining enterprise. This line has been in satisfactory operation for over two yearn; its details will be referred to later. But beside their importance as feeders, ropeways are valuable as a means of conveyance between works and distant warehouses, and between separate buildings in the same works. Their rapidly spreading introduction for such purposes indicates how keenly the necessity of effecting economies is felt under the stress of an everaccentuating competitiop.

Jan 1, 1891

By Robertson AC

Studies by Tennent, Isokangas Pty Ltd (TIP) have indicated that underground quarrying of backfill may be a cost competitive option for providing backfill for specialised situations in underground mining. Situations where suitable bulk fill material may not be available on the surface, and where the total cost of setting up a fill distribution system are prohibitive, could favour the mining of fill material underground adjacent to the stopes being mined. Considerations include environmental impact, scheduling, surface constraints and total costs. The examples quoted in this paper, and the case studies are based on the authors' personal observations and experience.

Jan 1, 1998

By Peter Fischer

Between 45,000 and 50,000 claims for subsidence are submitted each year to the German hard coal industry. In order to improve the service to claimants a quality management was established in 2005. This paper describes the process now used for handling these claims. A quality check has also been carried out by way of a customer survey, which was performed by an independent research agency. The results of the survey are presented in this paper. In Germany, research into mining subsidence mainly involves the prediction of ground movements caused by deep mining operations. Special areas of research are subsidence reducing aspects of the extraction panel planning, especially from the point of view of mining dynamics, as well as securing and restoration measures. This work seeks to prevent or minimize mining-induced damages close to the surface, for instance, buildings or infrastructure installations (such as pipelines), or underground mine openings (e.g. shafts). Roof collapses and surface fractures caused by shallow mine workings of an earlier era currently constitute a special area of investigation.

Jan 1, 2006

By L. M. Lowe, D. G. Feasby, J. R. Goode

"Rare earth resources usually contain minor amounts of radioactive elements. The most widely recognised sources of radioactivity are associated with thorium and uranium. However, also present in the resources are isotopes of rare earth elements (REE) that are themselves radioactive, including lanthanum (La-138), lutetium (Lu-176) and samarium (Sm-147). These radioisotopes, as well as remnants of the natural thorium (Th-232) and uranium (U-238, U-235) decay series, can contribute to significant levels of radioactivity in mixed REE concentrates and in separated products. Levels such as these can present challenges for transport, transboundary movement, product storage, workers’ health and safety, as well as waste management issues at the facilities that separate out the individual REE’s. These are discussed in this paper. A particularly challenging radioactive isotope is Ac-227 (a decay product in the U-235 decay series). Actinium behaves chemically similar to lanthanides and hence normally concentrates with REE multi-element composites. Reliable analysis of Ac-227 is not widely available and the methodology required to deal with this challenge is briefly described. A principle reason for minimization of radioactive content throughout REE processing is restrictive specifications by concentrate purchasers in order to reduce waste management challenges. Approaches to the minimization of radioisotope content in REE concentrates and separated products are outlined in this paper."

Jan 1, 2014

By E R. Hassall

Discussiong the importance of minerals and mining, impacts on the environment and remediation, and the need to foster interest in science among young people.

Jan 8, 1997

By Tom Martin

Mega projects present unique challenges with regard to estimating costs. With such projects, which may span decades, these challenges often begin as soon as a project is conceived. The importance of having a sound, resource based estimate avail-able early in the process cannot be overstated because it provides the basis for ongoing project decisions. For the final phase of providing an updated cost estimate, often while bidding by contractors is underway, the Engineer?s Estimate (EE) must incorporate present market conditions; account for possible volatile material price swings; be based on actual labor and fringe costs; rely on meaningful productivity rates; and accommodate any recent technology advances while identifying and allowing for risk factors. This paper explains the benefits associated with consultants adopting a contractor?s estimating approach when preparing the Engineer?s Estimate on mega projects like the various tunneling projects in New York City.

This publication contains four papers presented at a seminar on mine subsidence control held in Pittsburgh, PA, on September 19, 1985. The seminar was designed to keep the mineral industry informed of new technology developed by the Bureau of Mines that permits reliable and accurate prediction of mine subsidence. The papers describe actual field studies undertaken by the Bureau to monitor surface subsidence over longwall panels. Topics discussed include the efects of subsidence on water table levels, the development of subsidence pre calculation methodology suitable for use with the specific lithological conditions of the Pittsburgh coalbed, an engineering comparison of technologies used in surveying for longwall mine subsidence, and a comparison of the process of subsidence over two different longwall panels.

Jan 1, 1985

By J. L. Bowlby

The heats of combustion of fuels are determined in the laboratory by means of a calorimeter, usually of the oxygen bomb type. A known weight of the fuel is burned in an atmosphere of oxygen under approximately 400 pounds pressure in a heavy metal container-the bomb- and the heat evolved is imparted to a definite quantity of water. From the rise in temperature, measured by means of a Beckmann thermometer, and other data incidental to the determination, the heat value of the sample can be calculated. On paper, the method appears simple indeed, but in practice the determination of the heat of combustion is one of the most difficult of the various coal analyses. This h as led to considerable investigational work in order to obtain formula: whereby calorific values of solid fuels could be calculated from proximate analysis data al one. The proximate analysis of a fuel consists of the determination of moisture, ash, and volatile matter, with fixed carbon by difference. Sulphur determinations properly belong to the ultimate analysis, but in this section of the country, where the sulphur content of the coal is comparatively high, a request for the proximate analysis of a fuel implies the determination of the sulphur as well.

Jan 1, 1929

By Liu Yong

A complex rare metal ore, containing various valuable elements is used in this study. The mineralogy results indicate that the mineral composition of the raw ore is complex, and there are more than thirty-eight kinds of minerals in the raw ore, and the elements, such as Nb, Ti, Fe, REO, Be etc, always form isomorphism relationship. The REO content of the raw ore is 0.45%, and the contents of other rare metals Nb, Ta, Ti and Zr are 0.33%, 0.02%, 0.93% and 2.00% respectively, and the main gangue elements are Si and Al, and their contents are 71.84% and 8.5% respectively. The beneficiation-metallurgy combination process of ?preconcentration-reduction and magnetic separation-acidification and leaching-precipitation? is used to treat the raw ore. The preconcentration of raw ore is realized through high intensity magnetic separation, and the magnetic field intensity is 1.0T, and the rough concentrate with 2.88% REO and 1.95% Nbresidue can be obtained, and the iron recovery is 92.83%, and the REO recovery is 95.87%, and the Nbresidue is treated by hydrometallurgy process of ?acidification-leaching-precipitation?, then the rare earth oxide, niobium concentrate and zircon-bearing residue can be obtained, and the REO recovery is 80.10% and the Nbresidue and the gangue obtained from the high intensity magnetic separation process is separated by gravity separation, and then the zirconium concentrate can be obtained. The indexes of the beneficiation-metallurgy combination process used to treat the complex rare metal ore are as follows. The REO content of the rare earth oxide is 92.58% and the recovery is 58.44%. The Nb2O5 and 27.42% TFe can be obtained. Iron in rough concentrates is removed after reduction and low intensity magnetic separation, then the iron powder with Fe content over 88% and nonmagnetic rare-metal 2O5 recovery is 94.77%. The rare-metal 2O5 recovery is 80.04%. The mixture of the zircon-bearing 2O5 content of niobium concentrate is 28.34% and the recovery is 54.02%. The ZrO2 content of zirconium concentrate is 28.43% and the recovery is 52.35%. The TFe of iron powder is 89.53% and the recovery is 78.13%. Keywords: rare metal ore, separation and extraction, beneficiation-metallurgy combination, comprehensive utilization

Sep 1, 2012

By T. H. Etsell, P. Kerr

Over the past 50 years, there have been a number of geological, mineralogical and metallurgical studies carried out on the Clear Hills ironstone deposits in northern Alberta, Canada. Due to the low grade and complex mineralogy, previous metallurgical studies have achieved limited success. After rejecting some of the more ‘conventional’ techniques for iron ore beneficiation, the authors chose to investigate the grain enlargement/iron segregation process for the beneficiation of the Clear Hills ironstone. The segregation reactions for iron have not been explored in as much detail as they have for copper and nickel. Iron segregation roasting involves the addition of a carbonaceous reductant and a chloride transport agent to an iron oxide ore, and heating the mixture to an appropriate temperature. The benefit of this process is that it allows ores in which the value minerals are intimately associated with gangue minerals to be processed in circumstances where conventional iron ore processing techniques are not suitable or capable of upgrading the material. As iron is one of the few elements that can be transported through this process, a clean high purity metallic concentrate can be achieved.Through the use of crucible testing followed by Davis tube magnetic separation, scanning electron microscopy, X-ray diffraction and atomic absorption spectroscopy analysis, characterization of the reaction products has been made with an improved understanding of the reaction mechanism.

Jan 1, 2015

A wide range of drill holes and process streams are sampled for resource estimation, grade control, and contractual purposes in the minerals industry. However, despite the availability of training courses, conferences and both national and international standards on correct sampling practices, it is still surprising how often little attention is given to ensuring that representative samples are collected for analysis. The reason for this is that the responsibility for sampling is often entrusted to personnel who do not appreciate the significance and importance of sampling, with cost being the main driving force rather than whether the sample is representative of the material from which it was extracted. This seriously undermines the precision and accuracy of the analyses subsequently generated and can render the analysis process a total waste of time and money and expose mining companies to serious, potential, financial losses. Company management needs to reverse this situation and ensure that sampling is given the attention it deserves to generate representative samples for analysis.

Jan 1, 2010

By M. R. Samis

The great variability of mineral and energy prices has motivated some governments to incorporate a windfall profits tax into their mineral taxation regimes. Windfall profits taxes are a means for governments to capture additional mineral revenue when mineral prices are considered higher than some historic level. Governments need to be aware of the effects of such contingent taxes on the exploration, development and operating decisions of mining companies. Mining companies need to be able to calculate the full impact of windfall profits taxes on the economics of their projects. This paper examines the valuation of a multi-phase copper-gold project in the presence of a windfall profits tax. Real options Monte Carlo simulation is used to characterise the different exposures of the mine owner and of the government to the risky cash flow streams that they receive from the project. The results highlight that Monte Carlo simulation paired with the real option valuation method is able to account appropriately for the differing risk exposures, while the traditional discounted cash flow valuation model is not. Our key conclusion for governments and mining companies is that the impact of contingent tax and royalty terms can and should be assessed using advanced valuation techniques, and the results used to improve contract designs under the constraint of actual and perceived fiscal system stability.

Jan 1, 2007

By J. F. Barkley

The following questions and answers were prepared principally to supply information in answer to general inquiries received by the Bureau from those contemplating the use of propane and butane fuels . Primary or basic information only is covered; this usually gives enough guidance for most inquirers . To those who wish information of the treatise type , the handbook , Butane- Propane Gases , published by the Jenkins Publications , Inc. , 1709 West 8th Street , Los Angeles 14, Calif . , is suggested .

May 1, 1949

By J. K. Brimacombe

Since the Peirce-Smith converter was introduced to the non-ferrous industry in the early part of this century, there has been a paucity of research on process-engineering aspects of the reactor such as gas injection. This paper reviews studies conducted at UBC over the last decade on gas discharge dynamics, high-pressure injection, bath slopping, oxygen/bath reaction kinetics and out-of-stack heat transfer within the converter. The ultimate objectives of this work have been to extend refractory life and to increase converter productivity.

Jan 1, 1985

By Tamás Megyeri, Dániel Borbély, Vera Szánto, László Kovács

"Upon completion, the Bátaapáti deep underground radioactive waste repository complex (National Radioactive Waste Repository - NRWR) will provide safe final disposal for low and medium-level radioactive waste from the Paks Nuclear Power Plant in Hungary. The waste emplacement is in progress and one of the main concerns related to the development is ensuring a feasible plan is in place for permanent repository closure. Detailed hydrogeological observations and safety assessments revealed that the clay filled fault zones penetrated with the access tunnels play determinant role in the long-term confinement performance of NRWR, so they need to be plugged. Detailed mechanical analysis and numerical modelling of the tunnel constructed through a fault zone is presented here to gain a better understanding of the rock mass and rock support behavior. The effect of stress reflection is demonstrated and its consequences are described in detail. A recommendation is given for tunnel support design in such conditions. INTRODUCTION Crossing fault zones is a challenging task during tunnel construction and can lead to failure if not properly accounted for during design and construction. These failures are can be caused by high water inflow or stability loss of the rock mass surrounding of the tunnel (examples can be found in CEDD, 2015). The prediction of the magnitude and development of displacement has a considerable impact on issues during tunnel construction. Changes of rock mass stiffness or structure ahead of the face, to a great extent influencing stresses in the vicinity of the tunnel and thus deformations (Steindorfer, 1998). Further research with numerical simulations was carried out, and the qualitative and quantitative evaluation of displacement vector is presented in (Grossauer et al, 2005). The concern associated with crossing fault zones was considered during the design of the Bátaapáti deep underground radioactive waste repository complex (NRWR) in Hungary. In the case of NRWR project, the fault zones have an impact on maintaining the stability of the surrounding rock mass as well as the final sealing of the repository. As part of the final closure design, a complex numerical modelling program was completed to gain a better understanding of the mechanical behavior of the rock mass and the monitoring observations during construction. Even though the need for the presented study is closely related to the NRWR project, the results can be used in any project related to fault zone crossing. The methodology used to better understand the impact of crossing fault zones for the NRWR project is presented in this paper. First the project background is introduced including an overview of the underground facilities, the aim of the repository, and the construction experience gained from the first crossings of the fault zones. After that the in-situ and laboratory testing is summarized. The numerical modelling methodology is detailed in the next section. Not only the outcome of the model is presented, but the results are compared with the experience and observations made on site. Since a good agreement is found between the actual and the modelled behavior, the conclusions are based on the validated result. To fulfill the aim of the paper, the stress reflection concept is introduced to explain the mechanical behavior of the fault zone and the rock support; furthermore straightforward suggestions are made for rock support design."

Jan 1, 2016

By L. J. Barnes, R. O. Koch, J. H. Versteegh, P. J. H. Scheeren, F. J. Janssen

Following two years of laboratory research with bench scale reactors, a 9 m3 experimental process demonstration reactor was installed at Budelco's zinc refinery to treat their underlying groundwater. A 600-fold scale-up was successfully achieved. It has demonstrated that this anaerobic microbial process can remove a wide range of heavy metals and sulphate to the required levels. Extended operation of the demonstration unit has shown that the process is robust, can withstand wide variations in feed composition, rapidly recovers from operational upsets and is easy to start up and shut down. The metal sludge produced can be processed in a metal refinery to recover both metals and sulphur.

Jan 12, 1992