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By J. A. Hrabik

The feasibility of mining deep phosphate deposits by a borehole mining system was compared with mining by proven conventional techniques. An economic comparison of the borehole mining system with conventional dragline and bucket wheel excavator mining systems was completed at various mining depths and production rates. Hypothetical phosphate deposits, with various overburden thicknesses and reserve tonnages, were defined. Geologic conditions necessary for the application of the borehole system were identified. Discounted cash flow analyses based on derived capital and operating costs were used to generate rates of return and product prices. Borehole mining was found to be more economical where overburden thickness was 46 m (150 ft) or greater. However, at 15- and 30-m (50- and 100-ft) thicknesses, conventional surface mining was more economical. Overburden thickness has a great effect on the economic feasibility of the conventional mining systems but less effect on the economics of borehole mining. Economies of scale are only realized in conventional mining, since larger equipment is used to achieve greater production, whereas increased production from borehole mining is achieved using additional equipment units. A comparison of the environmental effects of borehole and conventional surface mining systems showed that borehole mining is environmentally more desirable.

Jan 1, 1987

By Kevin R. Burns, William A. Depree, John J. Jansky

This paper presents some of the work associated with the reduction of employee exposure to diesel and blasting contaminants at an underground salt mine. The purpose of the paper is to outline the procedures recommended in resolving the problems associated with these contaminants. The first stage consists of a complete mine ventilation survey. The purpose of the survey is to identify any problems in the mine. The survey consists of air quality, air quality and ventilating pressure measurements taken throughout the mine. After completing the survey, the information is analyzed to identify problem areas and the possible causes. All available solutions to reduce the levels of contaminants are then explored and evaluated for feasibility. The PSU Mine Ventilation Simulator is then used to accurately simulate possible changes to the ventilation system. These ventilation projections are a useful tool to illustrate to the company and union personnel the possible benefits of various ventilation changes. This paper will illustrate the phases involved in making important and sometimes expensive ventilation decisions. Through the cooperative efforts of MSHA, company and union personnel, the levels of contaminants have been reduced by approximately 200 percent. As a result of these ventilation improvements, the company can now safely increase production approximately 25 percent.

Jan 1, 1987

By P. Somasundaran, S. E. El-Mofty

A comparison of the IMC Anionic Process and the CLDRI Process, based on pilot plant testing of waste pebble by Jacobs Engineering is presented. Estimated costs for constructing and operating a beneficiation plant utilizing dolomite flotation are given. Research to develop practical flotation processes for removing dolomite from low-grade phosphate rock has been a high priority for the Florida Institute of Phosphate Research. The Institute funded the above pilot plant programs in 1998 and 2000. The Florida Phosphate industry currently deals with the increasing dolomite content of ore reserves by practicing selective mining. Heavy media separation plants installed at two mines to remove dolomite from pebble are not being operated. The flotation separation of dolomite from waste pebble requires that the flotation feed be ground. Grinding liberates the mineral species and produces particle sizes small enough to be floated. Only two dolomite flotation processes, the IMC Anionic Process and the CLDRI Process, have been successfully demonstrated on flotation feed that has not been deslimed after grinding. Deslimed flotation feed, relative to undeslimed feed, has improved flotation performance and reduced reagent consumption. However, for the above mention processes, undeslimed ground feed increases the yield of concentrate because the phosphate desliming losses are avoided.

Jan 1, 2002

By Chas. E. Shumate

There is assembled here this morning in Chicago the heartland of America, what is undoubtedly the greatest concentration of Technical, Scientific and "CAN DO" knowledge ever assembled in America. The participation in this Conference by the representatives of so many nations is particularly impressive and is a further indication of the importance of the subject matter of this conference which you will be discussing in much detail during the next few days. Another impressive feature of this Conference is the participation of a large segment of the construction industry in whose hands fall the job of building what others design. Also strongly represented is the manufacturing industry whose capability is well known throughout the world. They have the resources to design, develop and manufacture the machines and specialized equipment needed to do any job which the world requires. You should not expect to gain any knowledge from my few remarks this morning as I am undoubtedly the least qualified individual in this room on the highly technical and scientific subjects you will be discussing during these next few days. However, I shall offer a few broad suggestions on subject matter which I trust may generate serious thought during your discussions.

Jan 1, 1997

By C. A. Fleming, K. W. Sarbutt, P. K. MacPhail

The SART process has been developed for Teck to treat bar­ren solution from the cyanidation/CIP process that has been developed for the Lobo-Marte project in Chile. The objective of the process is to recover cyanide in a form that is suitable for recycling to the leaching part of the process. The Marte and Lobo ore bodies require a dosage rate of about 2 kg/t NaCN, of which only 0.5 kg/t is truly consumed (as thiocyanate, cyanate and ferrocyanide species). The remaining -1.5 kg/t is present as cop­per cyanide (-1 kg/t) and free cyanide (-0.5 kg/t), and is poten­tially recoverable and recyclable. SART is an acronym that describes the unit operations in this cyanide recovery process; namely, .. Sulphidization .. Acidification .. Recycling of precipitate " Thickening of precipitate The basic chemistry has been applied previously, and has also been the subject of two patents (American Cyanamid Company, 1965, Potter et al., 1986). The process involves the conversion of all free and WAD cyanide in solution to hydrocyanic acid by acidification of the tailings solution to pH :s,4, and the conversion of all copper in solution to cuprous sulphide (synthetic chal­cocite) by the addition of a sulphide salt:

Jan 1, 1998

By P. Tsakiris

The increasing social interest for the environmental issues, forces the authorities to enact more rigorous regulations. The mining industry is one of the sectors that concentrate vigorous remonstrance. It is an absolutely justified reaction, as a result of the numerous contaminated and polluted sites that have been inherited by previous operations and they remain unremedied. The lack of a consolidated global legislation, transfers the burden of decisions to the national level. This paper consists of two parts. At the first part, it discusses the critical role of the state to form an effective environmental policy, feasible for the context of the national economy. Afterwards it analyses two of the main points, which must be considered by the regulator for the excavation activity, the abandoned sites and the duration of the mining investment. The aims are to defuse, in the short-term, the public pressure, protecting the economic growth and, at the same time, to form a basic structure for the development of the corporate social responsibility. The second part presents an alternative financial instrument for the Greek regulatory framework, conformed to the characteristics of the Greek Economy, and analyses the expected benefits both for the business and the social welfare.

Jan 1, 2002

By J. Loredo

In some rural regions of Peru, artisanal gold mining is currently an essential activity as it provides an important source of income. In the Huanca region (Ayacucho Department) gold deposits are not attractive for mining companies due to their reduced size, but they have enough interest for artisanal mining because of the ease and low cost of mining operations. Artisanal gold mining represents an important damage for the environment, because operations related to amalgamation processes using Hg result in special environmental problems besides the typical ones commonly associated to all mining activities. A preliminary sampling has been made in soils, materials from tailing ponds and surface water of the Acarí River, at the site of the Huanca village, according to networks specially designed for the particular conditions of the area. Studies accomplished revealed high mercury concentrations in soils and tailings. Chemical analyses of soils directly collected in the area of the active or abandoned ?quimbaletes? show mercury concentrations ranging from 15.3 mg?kg-1 to 44.2 mg.kg-1. Mercury concentrations in soils decrease as a function of distance from the before mentioned sources. Water quality of the Acarí River that flows through the area does not present important changes as a consequence of the mining and processing operations.

Jan 1, 2006

By Quan Li, Xiang Ren, De Lui, Yumin Zhang

SL-type continuous centrifugal separator with injection flow (Injection Flowing Film Centrifugation, IFFC) for separating fine and ultra-fine minerals has been developed recently in China and it is capable of recovering particles down to one micron in size. In this paper, the principle of its separation is discussed. IFFC is a special transient pulsating film which combines both thin film jigging and thin film concentration functions. It not only can intensify the looseness and stratification of the settled particles, but also create a hydraulic weir effect to improve recovery of fines and ultra- fines and significantly improve the performance of thin film separation. In a Chinese tin gravity concentrator, SL devices, SL-1200s (capacity 1.5-2.0 ton/hr) and SL-600s (capacity 0.5 ton/hr) were applied to treat -1 0 micron cassiterite slime(removed as tailings at the past) and to replace the old tin flotation system(-74+10 micron slime). The plant results show that 50-60% of the cassiterite can be recovered from -10 micron slime with an enrichment ratio of 10-12. Particle down to one micron were recovered. Under optimal conditions, the recovery from -74+10 micron slime can reach more than 85%. The recoverable size range can be determined by calculation.

Jan 1, 1995

By Michael E. Kelahan, Charles Y. Guan, Glenn A. Gruber

A comparison of the IMC Anionic Process and the CLDRI Process, based on pilot plant testing of waste pebble by Jacobs Engineering is presented. Estimated costs for constructing and operating a beneficiation plant utilizing dolomite flotation are given. Research to develop practical flotation processes for removing dolomite from low-grade phosphate rock has been a high priority for the Florida Institute of Phosphate Research. The Institute funded the above pilot plant programs in 1998 and 2000. The Florida Phosphate industry currently deals with the increasing dolomite content of ore reserves by practicing selective mining. Heavy media separation plants installed at two mines to remove dolomite from pebble are not being operated. The flotation separation of dolomite from waste pebble requires that the flotation feed be ground. Grinding liberates the mineral species and produces particle sizes small enough to be floated. Only two dolomite flotation processes, the IMC Anionic Process and the CLDRI Process, have been successfully demonstrated on flotation feed that has not been deslimed after grinding. Deslimed flotation feed, relative to undeslimed feed, has improved flotation performance and reduced reagent consumption. However, for the above mention processes, undeslimed ground feed increases the yield of concentrate because the phosphate desliming losses are avoided.

Jan 1, 2002

By G. Buchan

This paper discusses the design of long panels for longwall mining at Twentymile Coal Company (TCC) from conception to implementation. The case study of the long panels at Twentymile includes extensive mine plan reengineering in the early 1990's to world record production months in 1996 and 1997. The obstacles of subsidence engineering, environmental regulations, conveyance, ventilation, equipment design, and continuous miner (CM) development timing had to be overcome to successfully begin longwall production within a 4 year time frame. The background and some detail for each of these areas listed will be discussed to show how the coordination of many facets must be pulled together to implement a successful long panel mine plan.

Jan 1, 1998

By C. R. Stephan

Explosion-resistant seals in underground coal mines isolate the environment within the sealed area from the active workings of the mine. The current United States Title 30 Code of Federal Regulations (CFR) requires these seals to be constructed of solid concrete blocks. The CFR also allows for alternative methods or materials to be used to create a seal if they can withstand a static horizontal pressure of 138 kpa (20 psi), provided the method of installation and the material used is approved in the ventilation plan. The purpose of this report is to identify those explosion-resistant seals that have been tested and meet or exceed all the requirements of the CFR.

Jan 1, 1997

By Michael Schultz, Gregory Sanders

The City of New Haven is proposing to construct Downtown Storm Sewer Infrastructure Improvement project to mitigate on-going stormwater flooding in the Long Wharf District. The proposed project includes a 200 cubic feet per second (cfs) stormwater pump station; and a 914 meter (3,000 linear feet) long tunnel segment with an internal diameter of 2.1 meters (84-inches). The tunnel alignment will cross under the Long Warf railyard and then continue parallel to the Vison Trail Route. This paper presents the local geology and subsurface conditions, as well as discusses the major project challenges and risks including construction in soft marine soils and encountering remnants of the former wharf.

Jun 13, 2021

By S. C. Sethi

The paper presents an analysis and discussion of the underground ventilation system at the waste Isolation Pilot Plant (WIPP), with particular emphasis on specific repository-related requirements and the gradual evolution of engineering designs relative to the WIPP Project scope. The underground facility has been constructed with three shafts. Additional studies, coupled with actual site-specific experience, have established? the need for construction of a fourth ventilation shaft to double the under-ground airflow. As a research pilot project, and the first of its type in combining mining and nuclear technologies, the WIPP Project is accumulating data and experience that may be fruitfully applied in the future designs of ventilation systems for planned commercial nuclear waste repositories.

Jan 1, 1988

By S. Rideout

As Assistant Director for Program Support for the Office of Surface Mining Reclamation and Enforcement (OSM), a bureau of the U.S. Department of the Interior, I am responsible for the regulatory and abandoned mine land programs under the Surface Mining Control and Reclamation Act of 1977, which governs the environmental impacts of coal mining. My perspective is influenced by my current position and my previous positions in government and private industry. Sustainability is a cooperative effort of many parties and can only be achieved if each assumes their responsibilities for making it happen. I will highlight some of my thoughts on the role of government in achieving sustainability in the mining arena.

Jan 1, 2007

By Roshan B. Bhappu, Sukhendu L. Barua

The economics of developing and operating small precious metal mines are unique and require much more scrutiny than larger mines since a limited tonnage must carry a heavy burden of capital investment as well as operating cost per unit ton to be mined and processed. Moreover, potential operators of small mines do not have the required expertise available to critically evaluate the technical and economic aspects of their projects. In this paper, the authors have attempted to provide technical and economic guidelines for developing and operating small precious metal mines. Capital and operating cost estimates as well as return on investment are provided for various scenarios utilizing different mining and processing techniques.

Jan 1, 1987

By Mucella Ersoy, Nese Celebi

Management Information System (MIS), is a system using formalised procedures to provide management with appropriate information to make timely and effective decisions. Before developing MIS, first functions of the organisation should be defined and grouped into subsystems. After determining the information required and produced by each system and interaction between subsystems, the related data resources should be structured into a series of databases and files. In this study, the MIS developed for Soma Open Pit Mines, Turkey is described in this respect. First, analyses of the existing system including user requirements and scope of the system are given. Then the designed information system, its subsystems, interaction between subsystems and system structure are presented in detail.

Jan 1, 2002

By I. E. Zevgolis

A comprehensive critical review on the subject of sulfates-induced swelling behavior of lime-treated soils is presented in this study. Starting with the description of a well documented case study, the mechanisms behind the swelling behavior and the factors that affect this behavior are discussed. Then, the major experimental methods of sulfates content determination are briefly presented. Finally, an attempt is made to categorize sulfates level and equivalent risk for civil infrastructure. The paper indicates that limited work has been done, not only on identifying safe conditions for use of chemical stabilizers in presence of sulfate rich soils, but also on developing materials and methods to avoid, or at least mitigate, the problem.

Jan 1, 2008

By J. P. Sieverson

The Comprehensive Environmental Response, compensation, and Liability Act (CERCLA -commonly referred to as Superfund) was passed into law in December 1980 in the wake of such incidents as Love Canal and the Valley of the Drums. Superfund was originally perceived as a way of cleaning up spills of hazardous substances and/or cleaning up abandoned hazardous waste dumpsites. In February 1981, Michael Cook, EPA deputy assistant administrator for hazardous emergency response, called Superfund "a tremendously powerful law. It could revolutionize the way the environment is protected, but we certainly don't intend to realize the full potential of the law for some time." These words have proven prophetic for Asarco's East Helena Smelter.

Jan 1, 1988

By F. P. van der Meer

Roller Press grinding has become an accepted technology in the cement industry, and finds a growing application in iron ore processing. Its introduction to the gold industry will depend on anticipated benefits such as a reduction in power requirements, the increase in throughput, and higher gold recoveries from the ground ore. The presentation highlights some of the specific features of the KHD Humboldt Wedag Roller Press and the effects of various operating parameters on the grinding result. Based on recent experiences examples are given on the use of the Roller Press in mineral applications. The anticipated reduction of grinding energy when using the Roller Press is discussed, together with the reduction in Bond Work Index.

Jan 1, 1997

By A. Kaczmarek

As the mining industry is enjoying a much needed and long awaited increase in demand for natural resources, consolidations in both the mining and mining service industries and a generational departure of experienced industry professionals is challenging today’s mining companies, not only in maintaining their existing operations, but also in securing qualified resources for developing new projects. These challenges are compounded for junior mining companies, oftentimes lacking in operating properties to draw from for experienced professionals and having to compete with the majors’ “mega-projects” for experienced project personnel from the reduced ranks of engineering companies. This paper discusses some strategies developed by Anatolia Minerals Development Limited in developing its Çöpler Gold Project in central Turkey.

Jan 1, 2006