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By Steve Wiig

In 1987, the Rock Springs, WY district office of the US Bureau of Land Management (BLM) began to develop an automated system to store, maintain and manipulate more than 14,000 drill hole logs contained in the district's office files for various solid leasable minerals. The development of this system was based predominantly on a trial-and-error basis, with many procedural changes incorporated over time. The current Automated Drill Hole Database and Analysis System will continue to evolve with new software developments and increased personal expertise in this field. The mission of the BLM's Branch of Solid Minerals is mandated by a series of federal laws. The most important are The Mineral Leasing Act, the Federal Land Policy and Management Act, the Federal Coal Lease Amendments Act and the Surface Mining Control and Reclamation Act. Several regulations, promulgated from these laws, dictate that BLM must perform certain tasks and functions as part of its specific duties. The regulations that apply to the BLM Solid Minerals program are codified at 43 Code of Federal Regulations (CFR) 3400 for coal, and at 43 CFR 3500 for non-energy solid leasable minerals, such as sodium, phosphate and potash. Specific functions required of the Branch of Solid Minerals necessitates the use of geologic and drill hole data analyses. These functions can be divided into pre-lease and post-lease. Examples of pre-lease functions that normally require some level of drill hole data analyses include:

Jan 1, 1992

By 1980, the U.S. mining community had reached a broad consensus regarding coal pillar design. The pillar load could be estimated from tributary area theory, and the pillar strength from empirical formulas and laboratory coal strength testing. Then the growth of longwall mining required new thinking. Recently, powerful design methods have emerged from analysis of large data bases of real-world pillar successes and failures. These include the Analysis of Retreat Mining Pillar Stability (ARMPS), the Analysis of Longwall Pillar Stability (ALPS), the Mark-Bieniawski rectangular pillar strength formula, and guidelines for preventing massive pillar collapses. Sophisticated numerical models have also helped transform the pillar design landscape. In the process, our understanding of pillar mechanics has been greatly enriched.

Jan 1, 1999

By William R. Yernberg

The combined 80th Annual Minnesota Section of SME Meeting and 68th Annual University of Minnesota Mining Symposium was held April 17 and 18, 2007, in Duluth, MN. About 350 mining industry professionals attended the conference, including engineers, executives, mining managers and suppliers from the United States, Canada, Australia, Finland and Brazil. This year’s theme was “Consolidation – Growth – Technology.” The 80th Annual Minnesota Section of SME meeting included concurrent technical papers sessions, a keynote session that featured two distinguished speakers and a general managers session in which taconite mine operators provided updates on their operations. The Minnesota Section meeting also offered an SME short course titled “Control the Feed, Control the Mill.” More than 50 individuals at-tended the short course.

Jan 1, 2007

By A. E. Koski

Two of the largest industries in northern Michigan, pulp and paper manufacturing and iron mining, formed a mutually beneficial partnership and collaborative research program to utilize paper mill residuals for waste rock stockpile reclamation. Historically, the majority of the paper industry’s residuals have been disposed of in landfills. The beneficial use of paper mill residuals for mine reclamation provides an environmentally sound recycling solution for the solids generated at northern Michigan paper mills and eliminates the need to strip additional overburden (glacial till) for final mine reclamation. Residuals offer a cost-effective source of organics and nutrients necessary for successful reclamation and waste rock stockpiles offer an economical and environmentally sound solution for disposal of residuals. The goal is to successfully pioneer technical development of paper mill residuals to accomplish vegetation of steep waste rock stockpile slopes and benches to establish a self-sustaining plant community that meets final reclamation requirements. Of the various types of iron mining wastes, rock stockpiles pose the greatest reclamation challenge. Success depends on incorporating sufficient organic matter into the rock stockpiles to produce a growth medium that can sustain vegetation without the need of overburden. This is an ongoing research program that is evolutionary in nature with numerous field trials, greenhouse studies, data collection and monitoring over multiple growing seasons. The program is a combination of innovative ideas and accepted reclamation practices that is proving to be a beneficial and economic approach to paper mill residual management and mine reclamation that will eventually lead from research to standardized reclamation procedures.

Jan 1, 2006

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.

By J. T. Bartlett

Life-of-mine process simulation is an interdisciplinary effort and a useful means of thoroughly evaluating mining and minerals projects. Communication between geologists, mine planners, miners, metallurgists, and managers not only benefits each discipline but facilitates design of an efficient operation and allows for accurate forecasting of productions and cash flow. By focusing on the key areas: geology; mine design; waste dumps; stockpiles; metallurgy; weather data; tailings disposal; using contours, block models, mine plans, process flowsheets, design criteria, operating and control strategies, maintenance schedules, and operating costs to perform detailed daily simulation from start-up to shut-down; a comprehensive understanding for all disciplines is achieved. Construction of a METSIM model that includes all test work and project data from drill holes through net present value calculations brings the pieces together to achieve optimum process design, minimize operating problems and eliminate the term ?black box? from project meetings and discussions.

Feb 27, 2013

By Richard J. Stoehr

In his time on earth, man has mined about 93.3 kt (3 billion oz) of gold. About one-half of this has been produced in the past 35 years. Roughly one-third of this gold is held as reserve in Central Banks. One-third held is in personal reserves. And one-third is held as jewelry or other fabricated products. The world per capita availability of mined gold is increasing. There are many forces shaping gold's future. Gold currently has a favorable exchange ratio. This is encouraging many new gold mining developments. Production is increasing and new recovery techniques are surfacing. The use of gold in the financial markets is increasing in some unique ways. And gold is again fulfilling its role as a universal money, making its future predictable. Gold Today Man is currently mining gold at the rate of about 1.4 kt/a (44 million oz per year). This adds about 1.5% of newly mined gold to the total supply each year. This production plays a small role in the pricing mechanisms since much of the 93.3 kt (3 billion oz) mined is available to the market in some form. The 31.1 kt (1 billion oz) held by central and international banking

Jan 11, 1984

By William R. Yernberg

The 2002 Arizona Conference was held Dec. 8 and 9, 2002, at the Doubletree Hotel at Reid Park in Tucson. The annual conference is organized by the Arizona Conference Board of Directors, which represents SME sections in Arizona and adjacent areas. The conference provides an opportunity for individuals and corporations associated with mining in the region to get together once each year to discuss the status of the industry. The meeting featured a keynote address, a distinguished lecture and about 30 technical papers. As was the case at the 2001 meeting, the economy, the price of copper and foreign competition continue to be the hot topics of discussion among the attendees. The domestic copper industry still faces challenges due to low copper prices dictated by the world market and because of a weakened domestic economy. There continues to be concern about the Arizona region’s copper industry in light of the mergers, downsizing and shutdowns that have occurred during the past several years.

Jan 1, 2003

MINExpo International is billed as the largest exposition for the mining and mineral processing industry. And the 2012 edition, scheduled for Sept. 24-26 in Las Vegas, NV, is no exception. Put on by the National Mining Association (NMA), attendance at this year?s show is expected to be significantly more than the 38,500 who attended the last MINExpo in 2008. The exhibit will also be quite a bit larger in 2012 than it was at the previous MINExpo. More than 1,800 companies, representing more than 30 countries, will fill the Las Vegas Convention Center. The more than 850,000 sq ft of exhibit space will include the North and Central halls as well as South Halls Nos. 3 and 4. And the Silver Lot outside of the front door, under construction in 2008, will be filled with more exhibitors. The 2008 show attracted about 1,220 exhibitors occupying more than 600,000 sq ft of exhibit space.

Jan 1, 2012

By M. Hancer, J. D. Miller

It is known from soluble salt flotation practice that the K, Mg double salts of kainite (KClMgSO43H2O), and carnallite (KClMgCl26H2O) are difficult to float and must be converted to other salts such as schoenite (K2SO4MgSO46H2O) and sylvite (KCl) in order to recover potash values. The flotation characteristics of these double salts have now been confirmed in some detail by carefully controlled laboratory experiments with both cationic and anionic collectors. The experimental results are discussed in view of recent experimental findings regarding the flotation characteristics of simple salts, in which the flotation response was shown to be determined by the interfacial water structure and whether the salt could be considered to be a water structure maker or a water structure breaker. The same approach can be use to explain the flotation response of the potassium double salts ; schoenite, kainite, and carnallite. In addition, the sign of the surface charge of schoenite (K2SO4MgSO46H2O), was determined as a function of pH from nonequilibrium electrophoretic mobility measurements. Schoenite appears to exhibit three charge reversals (CR) which can be explained based on surface hydrolysis reactions. The flotation behavior of schoenite is further considered based on solution chemistry calculations, electrophoretic mobility measurements, and microflotation results.

Jan 1, 2001

By E. M. Hill, H. K. Lin, J. L. Oleson

When activated carbon is used for recovering gold in gold industry, carbon fine materials are generated in stripping, acid-washing and kiln regeneration circuits. The carbon fines at the Fort Knox mine, Fairbanks Gold Mining, Inc., contain up to 0.68 kg/t (20 oz/st) of gold. In laboratory tests, gold in the carbon fines was effectively transferred to coarse virgin carbon when the carbon fines were mixed with virgin carbon in cyanide solution at a cyanide concentration higher than 0.10%. A plant-scale test conducted at the Fort Knox mine also shows effective gold transfer from the carbon fines to virgin carbon with a 95% gold recovery in a two-stage gold transfer process.

Jan 1, 2002

Coal that meets customer specifications is often stored in silos before being loaded into cars. It is often found that coal in a particular car does not meet customer specifications due to the mixing of coal inside the silo. Some new contracts require meeting specifications on a per car basis. Silo flow models are used to predict quality in such cases. However, coming up with an accurate silo flow model for each case is very difficult and time consuming. This paper examines the viability of using an online analyzer at the loading end of the silo in conjunction with a feedback circuit, to optimize the quality of the coal being loaded into trains, so that each car meets quality specifications.

Jan 1, 2000

By S. Mishra, C. Shon, D. Saylak

Only 40% of fly ash generated by the power plants in US are recycled and used for commercial applications. Of these, the high lime, Class C ash had been preferred. Systematic laboratory and field-scale studies have shown that, by including calcium chloride in the mix design of stabilization of roadbed materials, both Class C and Class F fly ashes can be effectively utilized. Test data reveal that the addition of calcium chloride to the system accelerates its curing rate, thereby increasing early strength and long term durability of the constructed road. For road construction, a preblended Class F fly ash–CaCl2 system tends to be more forgiving than the Class C fly ash–CaCl2 system. The former system produces more durable roads. The role of calcium chloride as an accelerator in these systems is discussed along with a mathematical model developed for fly ash- CaCl2 stabilized roadbed systems.

Jan 1, 2007

By Robert M. Miller, Judy Milligan

A computerized "Decision Support System" was used to evaluate an "Underground Platform Approach to Oil Recovery". Over a billion calculations were required to model the mine layouts; learning curves for shaft, tunnel, and well drilling scenarios; detailed cost, schedule, and resource data; complex oil production and material balance data; varying reservoir parameters; and complex oil pricing curves. Simplified "optimum" solutions were defined in terms of muck hoisting capacity, barrels of oil per day, and present worth. Complex "optimum" solutions were defined in terms of minimal exposure scenarios during development followed by shortest time to full production.

Jan 1, 1987

By Lynn B. Hales

There is a large economic opportunity associated with improving metallurgical performance in mineral processing plants that use process control. Thus, future control systems will be developed towards more sophisticated user friendly, computer-based systems that use powerful software analysis and control techniques. Auto-tuning, adaptive control and process models will gain expanded use because of their transparent availability to the system designer. Control of individual unit operations will be optimized and coordinated through expert systems that monitor economic conditions and management directives and direct operations accordingly. Plant areas, once considered cost centers, will be integrated into plant-wide control systems for economic control and optimization. This article looks at new control hardware, process sensors, control strategies and software development tools. It also looks at the economics driving the continued development of advanced process control systems. Process control systems routinely used in the mining industry were born when the microprocessor was invented. They have continued along an evolutionary path from vendor specific processing hardware and proprietary operating systems to computer industry standard "open architecture" systems. The many economic forces that drive the development and functionality of these process control systems will cause this evolutionary process to continue. Two of the broadest categories are the needs of the end users and the desire of the system manufacturers to distinguish their products from one another. More

Jan 1, 1994

By A. Robles-Vega

In recent years, tellurium has been extensively used in the manufacture of semiconductor materials. For this type of application, high-purity tellurium is required. Selenium, lead and silicon are usually the main impurities in tellurium. During the electrolytic refining of copper, tellurium gold and silver are collected in the anode slimes. A pyrometallurgical treatment is used to recover gold and silver from the decopperized anode slimes whereas tellurium is oxidized and skimmed off from the refining furnace as a Na2CO3-based slag. In the slag, tellurium is present as sodium tellurite (Na2TeO3), which is further water-leached from the slag. The first step in the conventional process for tellurium recovery consists of the precipitation of the tellurium contained in the leaching solution as tellurium dioxide (TeO2). The solid TeO2 is then dissolved under acidic conditions for its further reduction with sulfur dioxide gas (SO2). In this paper, an alternative route for tellurium production is presented in which a sodium tellurate [Na2TeO4] intermediate is obtained by oxidation of the sodium tellurite in an alkaline solution following the water leaching step. Sodium tellurate is then dissolved in acid media and high-purity tellurium is obtained by reduction with SO2 gas. Experimental tests under laboratory conditions indicate that the novel process yields higher precipitation selectivity for tellurium than the conventional process. A comparison of its efficiency concerning impurities co-precipitation with respect to the conventional process is discussed.

Jan 1, 2009

By B. Law, M. Menabde, B. Baird

Blasor is a new mine planning tool which is being used in the long and medium-term optimization of multi-open-pit operations throughout BHP Billiton’s Base Metals and bulk commodities portfolio. It is not just a scheduler, nor even only a schedule optimizer—although this function lies at the heart of the tool’s functionality—but a pit development plan optimizer, used from ultimate pit design and process plant capacity sizing right through to mining phase design and optimal panel scheduling. The tool uses a mixed-integer-linear-programming optimization engine to determine when material should be excavated and where it should be sent to optimize discounted operating cash flow over the life of operation. The core software design concept of Blasor is to provide a tool which is intuitive and flexible enough so that a competent mine planner can perform a pit development plan optimization without assistance from optimization specialists. To this end, a generalized graphical user interface has been implemented which allows full configuration of the optimization problem, including the definition of all inputs and constraints, specification of the material flow topology, bin and destination class definitions and full specification of the economic model encompassing prices and costs. This paper describes the capability of Blasor and outlines the design concepts underlying its design philosophy.

Jan 1, 2007

By Madan M. Singh

This section is unique to the Handbook in that it is the only section that deals with underground excavations for nonmining purposes. The editors were of the opinion that the section should be incorporated because the subject matter covered by the chapters is closely related to mining, and many mining engineers are currently involved in these activities. As we enter the decade of the 1990s activities in this category will increase, enhancing the relevance and utility of the material discussed. As the population increases, especially in metropolitan areas, the necessity to go underground will be greater. At the present time, not only are subsurface shopping malls and pedways connecting buildings becoming commonplace, but structures as diverse as the Civil and Mining Engineering Building on the University of Minnesota campus, a road-and-fleet maintenance facility in Multnomah County, OR, and even an ice cream parlor (Dairy Queen) in northern Wisconsin have been constructed underground. Placing utilities below the surface has numerous advantages and is now customary. Rapid transit and highways through tunnels in urban areas have been the norm for many years, but subterranean stormwater reservoirs, power plants, industrial warehouses, and food storage silos are relatively new innovations. The philosophy of underground defense installations is ancient, but their requirements and designs have trans-formed radically as technology advances. The use of under-ground space for disposition of wastes is modern, since it is recently that environmental concerns and waste disposal costs have assumed increased significance.

Jan 1, 2008

By D. Mohapatra

The possibility of using 2,2,4-trimethyl-1,3-pentanediol dissolved in tetrachloromethane as extractant for boron recovery is discussed. The parameters optimized for this purpose are contact time, boron concentration in the aqueous phase, extractant concentration, equilibrium pH and phase ratio. NaOH is used as stripping agent for boron recovery from the loaded organic phase. Boron extraction is found to be a slow process (equilibrium time 20 minutes) compared to boron stripping, which is reasonably fast (equilibrium time 5 min). Maximum boron extraction is possible at a broad pH range from 1.0 to 6.0. Using 1.0M extractant concentration, a 1:1 phase ratio (organic: aqueous) and two stages, ~99% boron extraction is achieved. More than 97% boron stripping is possible using 0.5M NaOH at a 1:1 (organic: aqueous) phase ratio in two stages. Overall, a 95.6% boron recovery was achieved. Loss of solvent into the aqueous phase and co-extraction of Ca, Na and K into the organic phase at higher equilibrium pH are two major concerns in his process.

Jan 1, 2008

By M. Hamarat

Freeport-McMoRan Copper & Gold (FCX) is committed to preserving and enhancing biodiversity in the areas in which we operate. As a member of the ICMM, FCX is committed to implement the 10 Sustainable Development (SD) Principles throughout our business. FCX is also a member of the Wildlife Habitat Council (WHC), a nonprofit coalition dedicated to protecting and enhancing wildl ife habitat. In alignment with ICMM SD Principle 7 and our Environmental Policy, FCX has set a performance goal to prepare a biodiversity inventory in 2010 and land management plan by end of 2011 for all active mining sites. In 2010 FCX established a Biodiversity Task Force to assist sites in biodiversity management; optimize use of resources around the globe; implement FCX goals and targets; and align biodiversity programs with ICMM principles and guidance. The task force consists of Environment and SD Department management, scientists and engineers from FCX sites, and WHC staff. The Task Force recently issued a biodiversity inventory guidance document to set expectations and provide consistency across the sites when developing a biodiversity inventory and land management plan.

Jan 1, 2011