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By Thomas P. Kwiatkowski, Len Cobb, Christopher D. Orlandi, Judith H. Jones

The Inland System supplies raw water to the industrial and domestic users in the City of Birmingham, Alabama. The Inland System, which is nearly 60 years old, consists of an approximately 57.9m (190 feet) high earthen dam across the Blackburn Fork of the Black Warrior River, a 39.6m (130 feet) high reinforced concrete intake structure, a 1524mm (60inch) diameter Dresser coupled steel transmission pipeline, and various distribution lines extending into Birmingham. The Inland System was owned, operated and maintained by the Industrial Water Board (IWB) of the City of Birmingham, an agency of the city government, from 1958 until 1994. In 1994, the City of Birmingham consolidated all water and distribution functions under the Birmingham Water Works Board (BWWB). In 1988, the IWB determined that the Inland System had reached a point where its reliability could not be assured without an in-depth evaluation and renovation. The IWB engaged Christy/Cobb, Inc. (CCI) of Birmingham as its consultant for the renovation work. CCI evaluated the Inland System and submitted a report to the IWB in April, 1992. The report contained several recommendations for capital improvements to the system including increasing the emergency spillway capacity, reconstructing the fuse plug, relocating public access to the lake away from the dam area, constructing a new intake structure, and constructing a tunnel through the dam abutment to deliver the water from the proposed intake structure to the existing 1524mm (60 inch) diameter supply line. The new intake structure and tunnel would provide for a future maximum demand flow rate as well as provide bypass and level control capabilities. CCI was authorized in 1992 to proceed with the engineering design for the renovation of the Inland System with emphasis on the spillway and intake structure. PROJECT DESCRIPTION The major component of the renovation of the Inland System was the new intake structure and tunnel through the dam abutment. CCI engaged Jenny Engineering Corporation (JEC) of Springfield, New Jersey as a consultant for the tunnel design. JEC was responsible for the design of the tunnel, the connecting shaft between the intake structure and tunnel, and the steel pipe final lining, while CCI was responsible for the intake structure and the connection to the existing supply pipeline as well as overall project management. CCI and JEC evaluated the project site in order to select the location for the new intake structure and set the alignment for the tunnel. A factor in the evaluation process was that the level of the lake could not be lowered to construct the new intake structure since the supply of water from the Inland System had to maintained. Therefore, a location was required which was

Jan 1, 1997

By R. Mathur

Cu isotope fractionation in low temperature aqueous environments has been well documented. Here we apply Cu isotopes to two distinct, yet related mining problems. First, an exploration geological application where we measured copper isotope fractionation in oxidized leach caps, chalcocite enrichment blankets and hypogene mineralization in 4 porphyry copper deposits located in South western USA. Cu isotope patterns exist in the lateral and vertical distribution within the mines coupled with distinct relationships with Cu grade. Second, a hydrometallurgical application where we measured the leach fluids, feed and residues from a quick leach text of Cañariaco ores. The results indicate the relative proportions of the minerals providing Cu during leaching. Interpretations of the QLT test measurements indicate covellite is the dominant ore mineral providing Cu during leaching. Both applications clearly demonstrate the power and ability of using the Cu isotope technique to understand low temperature aqueous processed involving copper.

Jan 1, 2010

By Christopher J. Bise

INTRODUCTION Traditionally, the purpose of mine ventilation has been defined as diluting, rendering harmless, and sweeping away hazardous gases which may accumulate in the mine workings. In addition, the ventilation sys- tem must keep the mine air as close as possible to the composition of the outside air in order to provide a healthy environment for mineworkers and to prolong the useful life of mine equipment. When plans are being developed for opening a new mine, sound engineering dictates that a calculated estimate be made of both the maximum air quantity requirement and the accept- able mine pressure (head) loss related to the under- ground layout and projections. For efficient mine ventilation, the two problem areas that demand constant attention are (1) the control of fugitive air (through short circuiting or leakage) and (2) the provision of ample airway capacity. Fugitive air is that quantity of air which enters the mine but short-circuits the mine ventilation system through improperly constructed stoppings, doors, overcasts, etc.; it represents an investment in power consumption (to move the air by the fan) while providing little, if any, return on the investment. Typically, efficient mines are those that can deliver 50% of the air handled by their fans to the working faces. Paying close attention to a new mine's ventilation system at the outset can provide numerous benefits during the later stages of mine development. It has often been noted that the main cause of trouble in many mine ventilation systems can be found within a radius of 2500 ft from the fan installation. Ample airway capacity is essential to maintain the mine's head loss within manageable limits. Similar to an industrial ventilation setting, the mine's headings are the ductwork for the handling of air. The difference between normal industrial ventilation and mine ventilation is apparent when more capacity is needed; a plant can install new or larger ductwork, but it is difficult for a mine to install new entries or enlarge existing entries. Air velocities are usually maintained under 800 fpm to limit the stirring up of dust in the intakes. With this in mind, it is usually simple to estimate the number of entries required in the ventilation system. The problem that often arises, though, is when the system's capacity is overestimated and the required head loss to achieve the desired quantity is excessive. Experience has shown that problems are often encountered when the mine's condition requires much more than three inches of water gage to ventilate the mine on a day-to-day basis. Thus, if proper attention is not paid to these parameters in the preplanning and initial development of a new mine, it may take an extremely high water gage to achieve the ultimate quantity. This chapter will not delve deeply into the theory of mine ventilation; many other books have been writ- ten on that subject. Instead, the following sections will point out the important considerations that should take place before the development of a mine ventilation system, as they relate to normal industry practice. FUNDAMENTALS OF AIRFLOW Volume Versus Water Gage The common method of measuring ventilation pressure is in terms of inches of water gage (wg); one inch of water corresponds to a pressure of 5.2 psf (pounds per square foot). Further, airflow follows a square-law relationship between volumes and pressures where, as shown in the previous section, a doubling of quantity requires a quadrupling of pressure. Table 1 shows how heads and quantities are related. Using Table 1, it is readily apparent that, for the same mining conditions, an increase in pressure from one inch wg to three inches wg results in only 34,640 cfm when the initial quantity is 20,000 cfm. Pressure Losses Pressure losses in mine ventilation systems are caused by friction between the heading walls and the air stream and by shock losses due to abrupt changes of the air stream caused by obstructions. The common pressure-loss formula for mine ventilation is: [ ] where H is the pressure loss in inches of water gage, K is the coefficient of friction, L is the length of the airway in feet, 0 is the airway perimeter in feet, V is the air velocity in feet per minute, and A is the cross-sectional area of the airway in square feet. Table 2 lists the US Bureau of Mines schedule of friction factors (K) for mine airways. Recent research indicates that the values of K are slightly less for coal mines than those presented in the USBM Schedule, and Table 3 should be consulted in this instance. It should be

Jan 1, 1986

By T. W. West

INTRODUCTION This paper presents an assessment of conventional flotation technology. In addition it presents some ideas which can be used to change the perception of what may be done with conventional flotation equipment to maximize its efficiency. Perspective of Conventional Flotation Technology 1. Flotation in many coal preparation plants is defined as something between a necessary evil and a non-viable concept because: -Too much art is required on a continuous basis to achieve uniformly acceptable results. -It is expensive, the capital cost in dollars per ton of circuit feed for flotation and dewatering is high. -It is a difficult process to use when SO2 reduction governs system design and equipment selection. -It creates a product (fine coal froth) that is difficult to dewater in the presence of BTU/lb as-received pressures. -It is a difficult process to control from a management standpoint, there are no dependable set points to rely on. 2. Many froth cell circuits are 0.5m x 0 (nominal 28 M x 0) feed which is sourced from screen/cyclone underflows. The original intent was to obtain maximum yield at acceptable product quality and moisture using disc filters. (See Figure #1) 3. An alternate to conventional flotation and its perceived to be limits of efficiency, capital costs, etc. is to move towards such developing flotation technologies as column flotation, reverse flotation, and microbubbles. A lot of work is being done to move these concepts thru pilot stages into full scale, commercial plant operation. The majority of the coal producers and coal preparation plant designers view these concepts as being in the development/pilot plant stages. OBJECTIVES Based on the preceeding comments of the perspectives of the coal producers and plant designers, the options are limited. They can make do with what they have available to them in the way of industry standard equipment and practices or they can move forward with developing technology. I feel there is a third option: what can we really do today with what is available to us, without reinventing the wheel? APPROACH 1. When processing coal against ash and SO2 restrictions, the fine clean coal stream can be the best stream on the clean coal conveyor due to the release by size and the ability to create a high BTU/low sulfur (dry basis) product. 2. Targets: -Consistent raw coal size consist in the plant feed . -Do not put pyrites in the froth cells. -Adjust criteria defining good flotation away from yield towards maximum BTU recovery at minimum ash. -Limit the froth cell feed size consist to 0.15 mm x 0 (nominal 100M x 0). -Establish and maintain a correct, consistent percent solids in the froth cell feed. -Select flotation reagents with care. -Introduce reagents in the proper sequence.

Jan 1, 1988

By Michael L. Nave

Mining belt conveyor elements are becoming larger and more expensive. Conveyor reliability requirements are rising. Conveyor condition monitoring can aid maintenance, reliability, and risk management in conveyor system operation. This paper examines the application of condition monitoring in coal mining belt conveyor systems. Types and form factors of condition sensors are described. Example costs are included. Suggestions for OEM developments are examined. Application problems are discussed. Two simple cost case studies are presented.

Jan 1, 2000

By Robert A. Jankowski, Natesa I. Jayaraman, Jay F. Colinet

The U.S. Bureau of Mines evaluated the dust control effectiveness of two-phase flow systems in a full-scale model mine using a mockup of a Joy 14CM continuous mining machine. In a two-phase flow system, air and water flow simultaneously through the nozzle. Air pressure varies from 10 to 60 psi, and water at 30 to 50 psi. Coal dust was introduced at the face, and dust concentrations were monitored at the operator locations and in the return. When compared with a conventional spray system, a symmetrical two-phase flow system reduced dust levels during the box cut by 43 pct at the operator location, and 30 pct in the face return. Dust levels, however, increased at the off-operator position during the slab cut. A directional two-phase flow system reduced dust levels at both operator locations by more than 90 pct in the box cut mode. While the use of two-phase flow systems will reduce respirable dust levels and water usage, it requires an air supply to the miner. Moreover, the ability of the two-phase flow system to redirect the dust cloud makes nozzle orientation a critical factor.

Jan 1, 1991

By L. Meier, M. Dennis, J. Schieffer, K. Murray

"INTRODUCTION Contrary to popular belief, Arizona State Trust land is not public land. All uses of the land must benefit the Trust, a fact that is considered with the review of each application received for sale, lease, or permit. This includes applications for activities ranging from commercial development to recreation. In 1863, the Territory of Arizona was established by an act of Congress. This act reserved sections 16 and 36 in each township to be held in trust for the benefit of the common schools. Later, the Enabling Act of 1910 allowed the Territory of Arizona to prepare for statehood. This act reserved the additional sections 2 and 32 of each township for the common schools and granted another 2,350,000 acres to be held in trust for other beneficiaries. In all, Congress granted the State of Arizona almost 11 million acres. The State was to manage those lands and maximize revenue for 13 separate beneficiaries. To meet this mandate, the State established the Arizona State Land Department (ASLD) in 1915. During fiscal year 2015, the ASLD contributed $136 million to the permanent fund, bringing the total value to over $5.1 billion, through the sale and leasing of the land and natural products which includes minerals. The current inventory of State Trust lands includes 9.2 million acres representing about 12.7% of the State.The ASLD Minerals Section manages the exploration, development, and leasing of mineral products on State Trust land. We are not a regulatory agency, but a department guided by our fiduciary responsibilities to the Trust. Our mineral programs include: Exploration Permits, Mineral Leases, Mineral Material Leases, Geothermal Leases, Oil & Gas Leases, and Special Land Use Permits. INDUSTRIAL MINERALS ON ARIZONA STATE TRUST LAND Industrial minerals fall under the category of either Mineral or Mineral Materials Leases. Common industrial minerals found on Arizona State Trust land include potash, limestone, gypsum, salt, specialty clays, zeolites, crushed stone, and sand and gravel."

Jan 1, 2016

By Mark C. Holton

The mining industry has recently been. - experiencing a difficult period. Escalating costs, lower grades and deeper level mining, are a few of .the reasons' why interactive graphics or CADD (computer aided design and draughting) systems are increasingly being used. CADD systems which support powerful and flexible mining applications have great potential for making all forms of mining more efficient and effective. There are many application programs which address almost every aspect of mining. Most of these programs originated to satisfy a particular need. Graphics and other features were added until they, reached a point where they were commercially viable as a mining package. Because of their evolution these packages, lack many CADD-type features. Today there are powerful personal computers (PC's) and engineering workstations running the best CADD systems available. These systems, support hundreds of applications in almost every discipline. Mining was until recently not well supported by interactive graphics vendors because of the highly variable nature of mining and the lack of common standards. Users of CADD systems have experienced the benefits of CADD and come to expect similar features from graphic mining packages. Several developers of mining packagers have either attempted to include some CADD features or make their packages compatible with one or other CADD system. Mining can benefit greatly From a combination of interactive graphics (or CADD) and the right mining application software.

Jan 1, 1989

By A. Dale Wunderlich

Introduction Loss prevention programs have become absolutely necessary at any precious metals producing property. In the past eight years, one security company, specializing in precious metals mine, mill, and refinery security, has been involved in investigations at gold and silver properties that have resulted in 62 criminal convictions. Of those, all but five were employees, former employees, contract employees, or vendors for the company. Several of the cases involved losses of more than $1 million. The largest number of employees prosecuted from one investigation was 17. A recent case resulted in 12 criminal prosecutions and, several years ago, one involved an additional 12 criminal prosecutions. The most serious theft problem facing precious metals mines is employee theft. Is is estimated that 95% of the dollar losses from precious metals thefts can be attributed to employees. This does not mean there is no robbery or burglary exposure. There have been successful robberies, burglaries, and extortion cases. Most mining companies, though, provide better protection against external theft than from internal theft. That is one reason employee theft has reached epidemic proportions. Any product can be stolen No product is immune to theft. Precious metals investigations have involved the theft of high grade ore, dore, bullion, concentrates, precipitates, loaded steel wool, loaded carbon, and sump cleanup. Over a period of several years, this author's security agency has documented the theft of more than 22.5 t (25 st) of load carbon. Most mining companies do not protect the number one adsorption tank or the loaded carbon screens, which frequently leads to losses. Precipitates, electrowinning tank sludge, sump material, and concentrates are usually afforded lit¬tle protection because mine management believes it is too difficult to process. There are custom mills throughout the United States that will process any form of precious metals with no questions asked. This has become a particular problem since the certificate of ownership requirement has been eliminated by most states. Due to the large number of gold mines coming on line, many mine managers are being recruited from base metal mines, where primary security problems involve the theft of tools and company property. These managers do not understand the unique security problems associated with precious metals production. Consequently, they usually forego many security needs in the interest of economy. Unfortunately, numerous cases are on file where mining companies have suffered large losses because their physical security and their security procedures were not adequately addressed when the property was in its planning stages. Properly designed and appropriate equipment The most economical time to plan alarm/closed-circuit televi-

Jan 4, 1988

By A. W. Khair

This paper presents an analysis of the dynamics of bit wear on the productivity of the continuous miners. Two field surveys have been carried out. The first survey was to assess the impact of bit wear on productivity and production cost. The second survey was to study the wear characteristics of the cutting tool (i.e. magnitude, forms, and mechanisms of bit wear). Primary factors affecting bit wear is identified and laboratory experiments were carried out to study the effects of some of these primary factors on wear in detail. Results indicate that bit wear has a significant effect on the productivity of the continuous miners. Furthermore under the severe geologic conditions (i.e. cutting rock partings and roof and floor rocks) bit wear not only hampers the productivity, but also increases the production cost due to a higher number of bit consumption. This study also indicated that bit wear accelerates beyond 20% of the conical height loss which corresponds to 7% of the weight loss. This increase rate of wear is an indicative of higher abrasion between bit body and cutting material, resulting in a dustier environment.

Jan 1, 1993

By Matthew A. Omofoma, Andrew P. Hampton

The application of the Cyprus Cyanisorb process was investigated using a pilot scale facility at the NERCO DeLamar Silver Mine (DSM) in Owyhee County, Idaho. The purpose of this process is to remove cyanide from the DeLamar mill tailings slurry prior to its introduction to the tailings impoundment. This will maintain the tailings impoundment solution in a detoxified condition and thus prevent migratory bird mortalities. The cyanide removed is to be collected and recycled to the mill. The process successfully recovered approximately 90 percent of the weak acid dissociable cyanide (WAD), reducing the effluent tailings cyanide concentration from about 300 ppm to less than 20 ppm. This was accomplished by stripping the slurry with air in a packed tower and recovering the volatilized HCN in a packed absorption tower. Data were obtained for the design of the full scale facility including the stripping and absorption towers, currently under construction at the DeLamar Mine site. Finally, test results indicated that the final pH of reneutralization can be optimized to provide for minimal gold and silver losses, while selectively precipitating unwanted metal impurities (Zinc, Selenium, Iron, and Copper) from solution

Jan 1, 1992

By D. M. Thayer

Laboratory and pilot plant investigations have indicated that copper recoveries of 50% can be achieved with fine grinding and flotation of a copper reverberatory furnace slag, Microscopic and microprobe studies indicate that the recoverable copper is in the form of matte, chalcocite, and metallic copper; the percentage of copper in particles appearing to be copper-free was from 0.23 - 0.54%.

Jan 1, 1969

By Sergio Flores, Nate Long, William Hodder, Phil Rhodes, Tim McQueary

The Surface Water Supply Project Segment B3 is a 4 miles section of tunnel that will run East- West in Houston TX, from Hopper St to I-45. The tunnel will be mined by using a 128" Dia refurbished 1987 Lovat Tunnel Boring Machine capable of operating in Open or EPB mode. The tunnel will be temporarily supported with ribs and lagging and a 96" Dia pipe will be grouted into place. All four miles of this project are within Petroleum Pipeline Easements. The project includes seven shafts, 2000' of tunnel in potentially petroleum contaminated ground, crossing the Hardy Toll d, I-45, the nion Pacic ailroad ight of Way and multiple oil and gas pipeline crossings. This paper summarizes the planning and drive performed to date.

Jun 23, 2024

By Tim Neil, O&apos

Finnish mining traditions date back 400 years. The country was then one of Europe's major iron producers. Most of the mines in current operation, however, were started during the last 20 to 30 years. The Finnish mining industry must make do with limited resources. Deposits are usually low grade and small in size. Open-pit methods are used where possible. But thin ore bodies and harsh winters can impose severe restrictions. Underground mining is often the only option. Despite these handicaps, Finnish metal miners produce copper, nickel, zinc, vanadium, iron ore, cobalt, and ferrochrome. Ironically, the success of Finnish mining is rooted in a crisis the industry faced several decades ago. Mining costs were rising. High grade mineral deposits were nearly exhausted. It was vital that Finland develop new mining machinery and methods that afforded higher productivity. Cooperation between the Finnish mining industry and its equipment manufacturers was good. Partly as a result, the Finnish mining industry has turned itself into one of the most modern and efficient in the world. The Finns did this while continuing to meet the stringent safety and environmental requirements in force in the Nordic countries. Today, the share of domestic raw materials used by the Finnish metallurgical industry is decreasing. So the country increasingly depends on imports of ores and concentrates. To better provide these imports, Finnish mining companies have expanded their foreign operations. And, while importing raw materials, the mining industry has been exporting its technological and equipment know-how and expertise. Mining methods Conventional mining methods and machinery are used in surface mines. Drilling is the exception. It is done with Tamrock hydraulic track drills and 100 to 150 mm-diam (4 to 6-in.-diam) drill holes. Pumpable slurry explosives are used in larger open pits. Underground, sublevel stoping with open stopes is the most common mining method. It accounts for about 80% of all underground stoping. The main benefits of this method are low production costs, high mechanization, and easy control. The best productivity figures exceed 10 t (11 st) per man-hour, including all mining personnel. The development of cable bolting has made it possible to use sublevel open stoping even in relatively weak rock. Cut-and-fill methods, such as concrete-pillar stoping, inclined-wall stoping, and traditional cut-and-fill have also been used, combined with sublevel caving and room-and-pillar methods, according to local demands. Various fill materials and stabilization components have been investigated and tested for cut-and-fill methods. Sublevel open stopes are often later filled, to stabilize the surface or to allow pillar recovery.

Jan 10, 1988

By Greg Sanders, Michael Gilbert, James G. Shaughnessy

"A new raw water intake from the South Holston River to the Kingsport water treatment plant is under construction. The exploration for the 335 meter long horseshoe shaped tunnel design took advantage of the site topography along the alignment to better define the complex geology consisting of Knox Limestone and Sevier Shale formations separated by a fault zone. To assess the geological conditions and to determine the extent of the fault zone, a 183 meter long horizontal boring and geophysical investigation was performed along a portion of the tunnel’s horizontal alignment. Explorations defined the fault zone width at approximately 5 meters and packer testing along the alignment provided a means of estimating groundwater inflows. As the tunnel excavation advances, comparisons of exploratory data versus encountered conditions will be made. This paper provides details on the geotechnical investigation, lessons learned, and the influence of the geology on the tunnel design. PROJECT OVERVIEW The Kingsport WTP is supplied with raw water via the South Holston River. The City of Kingsport (City) owns and operates the Kingsport Water Treatment Plant (WTP). The existing raw water intake system, consisting of pumps, power supply, raw water piping and appurtenant facilities has been determined to be vulnerable to failure. The original Raw Water Pump Station (RWPS) was constructed in 1928 as part of the original Kingsport WTP project. The 1928 RWPS operated until 1970 when it was replaced by the existing RWPS. This existing system still utilizes the 1928 piping and piping tunnel. Improvements to the RWPS hydraulics and capacity are required to meet the City’s future water treatment needs. The system extracts water from the South Fork of the Holsten River and coveys it via three pressure pipelines to the WTP. The conveyance piping exits the RWPS, ascends approximately 23 m up a near vertical rock outcropping then enters a 120 m long tunnel. Upon exiting the tunnel the piping continues underground to the WTP. The drill and blast tunnel is horseshoe shaped and nominally 3.3 m high by 3.3 m wide. The easternmost 62.3 m of the tunnel is without any type of support. The remainder is lined with concrete. According to the City of Kingsport, the concrete lining was installed in the 1970’s as part of upgrades to the facility. An evaluation of the current facilities concluded that the conveyance piping was in poor condition and required replacement."

Jan 1, 2016

By K. T. Stafford, N. A. Iverson, V. T. McLemore

Laramide porphyry copper deposits are large, low grade (<0.8% Cu) deposits that contain disseminated copper minerals, breccias, and stockwork veinlets of copper and molybdenum sulfides associated with porphyritic intrusions in Southwestern New Mexico. Critical minerals, such as PGEs, tellurium, indium, germanium, and gallium are recovered from the anode slimes remaining after copper is refined. Detailed age dating, mineralogy, geochemistry, along with geologic mapping could refine the location of critical minerals within specific systems and could identify porphyry systems with elevated critical minerals that could become economic, in addition to the already produced copper, gold and molybdenum.

Feb 1, 2023

By H. M. Conger

I&apos;m really very pleased to be talking with you today about the environmental impacts of gold ore processing as part of this symposium on emerging process technologies for a cleaner environment. But before I talk about some of the newer developments that are coming, I would like to set the stage by reviewing some of the recent past. Over the last decade or so the U.S. gold mining industry has experienced remarkable growth, primarily in heap leaching operations, and not surprisingly there has been parallel growth of environmental regulations. At Homestake, we have had the excitement of bringing on-line a new mine embodying state-of-the-art technology and environmental planning, and during the same period the flagship of our company, the Homestake mine, has been brought into modern day compliance through the application of innovative environmental technology. This has been a learning process; in both cases we found that we had to develop new ways to meet our objectives. At our McLaughlin mine in California a major achievement was pioneering the use of pressure oxidation, or autoclaves, for refractory gold ores, and at the Homestake it was the development of a unique bio-treatment plant for wastewater. These projects were developed balancing operational goals, environmental concerns and costs, and I would submit that being cost-effective is our greatest challenge in the development of new, environmentally sound, process technology. In meeting that challenge, our job has not been made any easier by the myriad environmental laws and regulations that directly affect the design and operation of our facilities. Most of these constraints have evolved through the political process more or less independently, but in their application there often are over-lapping provisions. Adding to this complexity is the fact that action takes place in both state and federal arenas. As a result, state and federal roles sometimes become intertwined, and a good case in point is provided by various cyanide issues faced by gold producers. The vast majority of U.S. gold mining takes place in the so-called "mineral States," the western States that come under the Mining Law of 1872 as amended. This is the basic statute that provides for access and tenure to develop mineral resources on federal lands in those states. There is gold mining outside the defined mineral States, and there is also gold mining in the mineral States on private lands. Our own Homestake mine in South Dakota is one of the best examples of the latter category: located entirely on private land, it is nevertheless subject to at least 13 federal environmental statutes and some 29 federal regulatory requirements. There are also nine significant state statutory and regulatory requirements that apply. On federal lands in the mineral States there are numerous federal statutes and regulations which affect mining, over and above the current Mining Law. These, which are in addition to the laws applying to private land, include the National Environmental Protection Act and the Federal Land Policy and Management Act, among others. Still, those who advocate radical changes in the basic Mining Law would have us believe that sweeping environmental protection and reclamation provisions, not to mention new land use restrictions, are needed. Such changes could effectively prohibit mining on the federal public lands. Strict enforcement of our current Mining Law would have presented most of the abuses cited by the critics but if the Law is to be changed at all, I believe that, at a minimum, the principles of self-initiation and security of tenure embodied in the present statute should be maintained. These are critically important concepts, but there are other statutory and regulatory issues constantly before us as gold miners. Let me cite a few examples: Reauthorization of RCRA There are several bills being considered by Congress to amend the Resource Conservation and Recovery Act (RCRA) that have as their theme

Jan 1, 1992

Numerous underground coal mine ventilation seals have been installed in the United States of America prior to 2006 and after implementation of the Mine Improvement and New Emergency Response (MINER) Act. Seal engineering, design, placement, and construction is regulated in industry, but post-construction monitoring of seals is limited to visual inspection of the outby face and seal perimeter, convergence measurement, and atmospheric monitoring. To monitor seal integrity and to provide safe working conditions, a form of non-destructive testing (NDT) is necessary to accurately reflect the health of the seal by detecting post-construction changes, deterioration, or defects within in-situ seals in underground coal mines. Previous research from the National Institute of Safety and Health (NIOSH) has indicated the potential for utilizing ground penetrating radar (GPR) for assessing in-situ mine seals. This paper provides an update to the assessment of proposed NDT methods for seal evaluation using commercially available GPR technologies and systems. Full-scale free-standing seals and large-scale seal specimens were analyzed with an array of GPR units from various manufactures using multiple frequencies.

Feb 23, 2014

By J. A. Murray

Maintaining satisfactory air quality in electrowinning tankhouses is problematic and costly, particularly as plant operating current densities have increased. Conventional approaches have not proved completely effective. These include the use of beads, hollow spheres, surfactants and coalescer devices. They require powerful ventilation systems to be installed. As workplace and environmental regulations become more stringent, containment of the acid mist at its source is more attractive. An electrode cap system based on this approach has been developed and tested in two commercial copper electrowinning tankhouses.

Jan 1, 1996

By J. Drew

Oregon Resources Corporation (ORC), an industrial minerals mining company, is currently engaged in the development of a new process design that will allow the unique paleo-beach placer deposits of southwestern Oregon to be mined efficiently and economically, creating an additional domestic source for chromite, garnet, and zircon. Engineering design has been guided by the variable geology and mineralogy of the paleo-beach placer deposits as well as the need for a dry tailing scheme that resolves a lack of water resources at the placer locations and at the same time eliminates the need for slurry settling ponds, typical of paleo-beach placer operations in North America. Metallurgical study of the placer material was grouped into four distinct samples based on marine terrace deposition, geological facies, and mineralogy. Because the metallurgical samples represented the extremes likely to be encountered in all future Oregon paleo-beach placer ores, the process design is highly dynamic and will successfully adjust to meet the production needs. Water availability at the mining area is seasonal and will not support a typical placer operation?s water requirement needs for heavy mineral concentration. For this reason, ORC has developed a plan to construct the ore processing facilities near Coos Bay, where a municipal source of water is available. Raw ore will be transported from the mining sites approximately twenty miles one way to the processing facility with return loads hauling tailings back to the active pit. The need to haul dry tailings, return dry material to the pit for reclamation, and limit the amount of water being purchased from the municipality has driven the design of a unique water reclamation system. BACKGROUND Location and Access Economic concentrations of ?black sand? or heavy mineral (minerals with specific gravity greater than 2.85) have been recognized and studied in marine placers from Coos Bay to the mouth of the Rogue River, a distance of approximately 75 miles along the southern Oregon coast (Hornor, 1918; Griggs, 1945)(Figure 1). ORC will begin mining existing reserves approximately 20 miles south of Coos Bay in a region known locally as Seven Devils. Ore will be trucked north to the processing site near Coos Bay via use of existing county and state roads, including U.S. 101. The available facilities at the processing site include highway, rail, municipal water and electricity, natural gas, and a deep water port. At the time of this writing, the rail line had been abandoned, but was being pursued by the International Port of Coos Bay. It is anticipated that this will be serviceable at some time in the future. History The southern Oregon marine placers have garnered the interests of miners since 1852, when present day beaches were exploited for gold. The beach deposits were small and irregular in nature and were easily washed away by the major storms the coast endures during the winter months (Hornor, 1918). [ ] In the 1920?s, deposits at the beach were followed upstream to their paleo-beach terrace origins (Pardee, 1934). These terrace placers were mined, but with little success, as the cost of mining and processing was greater than at the present day beach deposits. The greatest effort to understand and delineate the paleo-beach terrace placers came during World War II. As the need for a domestic source of steel hardening chromite was evident, the heavy mineral bearing placers of southwestern Oregon provided just that. The U.S. Geological Survey, under guidance from the Oregon Department of Geology and Mineral Industries, began exploration drilling of the paleo-beach terraces in 1940 (Griggs, 1945). This work was part of the investigation of strategic mineral deposits and would ultimately supply much needed chromite for the war efforts. The first mining efforts began in 1943 by the Humphreys Gold Corporation and the Krome Corporation (Griggs, 1945). Black sand

Jan 1, 2009