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By Mark E. Gershon

A mixed-integer formulation of the mine scheduling problem is discussed and applied for the purpose of optimizing both the mine production sequencing and the mill blending and processing problems simultaneously. Previous attempts at solving these problems separately, although successful, fail to take into account the interrelationships between these problems. Project structure serves as the outline of this paper, which is directed towards a mining engineering audience. Generalized in its organization, this concept is useful for long, intermediate and short range scheduling. Actual applications are mentioned which show that the concept is also applicable to mining a variety of ores.

Jan 1, 1982

By D. W. Struhsacker

Mineral exploration has evolved into a sophisticated science which uses powerful scientific tools to make mineral discoveries. In addition to their usefulness in performing mineral exploration, these scientific tools can assist the exploration geologist in assessing environmental conditions at exploration sites. During exploration, environmental data acquisition should focus on data collection efforts which can be easily integrated into exploration activities, and should provide information needed for pre-feasibility and preliminary engineering design studies. Environmental studies performed during exploration should also include an environmental liabilities audit and a fatal flaw analysis to assess whether there are any unresolvable environmental or regulatory issues affecting the project. Performing extensive environmental baseline studies during exploration and project evaluation is neither necessary nor recommended. This paper describes opportunities to integrate environmental data collection with mineral exploration activities. This paper also examines how political and communication issues can affect the outcome of permitting efforts, and recommends a strategy to improve the industry's ability to respond to political challenges and to communicate with the public. This strategy integrates technical and political issues, and implements programs to convince the public of the mining industry's technological achievements and its commitment to resource stewardship and environmental protection.

Jan 1, 1994

By R. W. Sims

"He?s an SOB, but he's my SOB." Many of us have heard this line in reference to attorneys, and can appreciate the humor. However, the thought reflects a deeper attitude that lawyers should be used for attack purposes in the legal system or the regulatory process. Often, more permitting progress can be made with tact and flexibility than with inflexible, overly aggressive strategies. Usually, administrative hearings or other litigation work to the disadvantage of the applicant. Thus, I have concerns about approaching any permitting system with a hard-line attitude. On the other hand, the project team must always be prepared to defend permit applications and present a legally adequate case at public meetings, administrative hearings, or judicial proceedings. This paper discusses a number of strategies intended to increase the probabilities for successful permitting, whether opposition is informal or highly organized.

Jan 1, 1990

By Jeffrey M. Christian

Gold prices are rising, in what is coming to be seen as the beginning of a longer term upward trend. After languishing between $325/oz and $364/ oz from early 1991 into early 1993, prices began rising in the first half of 1993. Gold rose from a low of $326/oz in March 1993 to $414/oz on an intraday basis in early August. There was a speculative sell-off at that point, which took gold prices quickly back down to $350/oz briefly in October 1993. At that time, there still was a fair degree of skepticism about gold's price prospects. Many banks believed that gold prices could not mount a sustained rally. As prices dropped in August and September of last year, these suspicions seemed to be confirmed. Gold prices quickly rebounded, however, reaching $395/oz by early January 1994. The strength of this renewed increase led many banks, investors and others that had held negative views of gold to grow more positive. They began buying gold and trading it from the long side of the market. The result was that gold prices remained strong during the first quarter of 1994, trading between $375/oz and $390/oz.

Jan 1, 1994

By Lorraine B. Burgin

The extensive lead time to develop most Arizona copper deposits commenced with initial production efforts before the turn of the century, when the first attempts were made to recover gold and silver and later copper from the high-grade vein deposits of the territory. Each of these discoveries, prospects, and early operations had its own lead time and life cycle as economic production was attempted. Because prices of the metals fluctuated and the higher grade material was depleted, economics forced operations to close and companies to fail. Renewed interest in the property because of improved conditions, different interpretation of the geologic structure, or new promotional ability frequently resulted in the formation of yet another company to finance the exploration and, hopefully, the development of the property. This cycle of renewed activity and subsequent abandonment was and is common, accounting for many lead times and for the long period of time from the initial location of claims to large-scale production. In order to gain a perspective on the lead-time interval necessary to achieve development of a large-scale operation, the histories of several major Arizona mines were examined, rather than a simple listing of discovery and production dates of many mines to arrive at a statistical average. The Miami, Castle Dome, Copper Cities, San Manuel, and Twin Buttes properties were studied, and as much data as possible obtained on the Pinto Valley, Esperanza, Sierrita, Pima, and Mineral Park-Ithaca Peak properties.

Jan 1, 1974

By W. A. Haley

As far back as 1939 state laws have required reclamation of mined lands. Reclamation has been the topic of many discussions and presentations, especially since the late 1960's. In the past ten years many states have added legislation concerning the reclamation of coal-mined lands. In the near future, it seems certain that some federal regulations will be passed that will set minimum guidelines for the states to regulate. Besides the requirement of returning the land to the approximate original contour, future regulations will more than likely demand replacing topsoil from one to five feet thick. As regulations become more stringent, costs will rise accordingly. Since no one has developed a machine that can do all reclamation work by itself, it is necessary to review in detail the tools available and to select the most economical means.

Jan 1, 1976

By Daniel M. Flanagan

"Editor’s note: Each year, Mining Engineering features an industrial minerals review. Several people put in a fair amount of time in developing the material for this issue, all the while doing their own jobs. Thank you to the industrial minerals annual review editor, to the Industrial Minerals & Aggregates Division technical committee chair and vice chairs, and to the authors of the individual commodity profiles. Jim Norman, member SME, of Tetra Tech, is the industrial minerals annual review editor.Joe Garska, member SME, of Imerys, is chair of the Industrial Minerals &Aggregates Division’s Technical Committee.The technical committee vice chairs include:• Hyunjung Kim, member SME, of Chonbuk National University, agricultural materials.• Xihui Lin, member SME, of Kemira, ceramics and refractory materials.• Nikhil Gupta, member SME, of Virginia Tech, chemical raw materials.• Adam Rodriquez, member SME, of Penn State, construction aggregates.• LeDeana Roberts, member SME, of Imerys, fillers and pigments.• Harsha Kolla, member SME, of ChemEOR, sorbents, filters and process aids.• Edgar Blanco, member SME, of FLSmidth, specialty minerals.Their help makes possible this July industrial minerals issue. On behalf of ME readers, the editors thank them.During the past 25 years, U.S. ball clay production (the quantity sold or used by domestic producers) increased from 788 kt (869,000 st) in 1990 to an alltime high of 1.31 Mt (1.44 million st) in 2003 (Fig. 1). Housing construction within the United States, a leading market for ball clay-based ceramics and sanitaryware, began to decline in 2005, which resulted in a considerable decrease in sales of ball clay that continued through the 2008-2009 economic recession. After bottoming out at 831 kt (916,000 st) in 2009, ball clay production steadily increased through 2015 (Fig. 1). Estimated sales in 2015 were 36 percent higher than those in 1990 and 18 percent lower than those in 2003.Four companies (H.C. Spinks Clay Co., Imerys S.A., Old Hickory Clay Co., and Unimin Corp.), mined ball clay in five states during 2015. An estimated 1.7 Mt (1.18 million st) of ball clay valued at an estimated $47.5 million was sold or used by U.S. producers, a 4-percent increase from 1.03 Mt (1.14 million st) valued at $45.2 million in 2014. Approximately 65 percent of total ball clay production was air-float, 25 percent was crude or shredded and 10 percent was water-slurried"

Jul 1, 2016

By Harrison A. Schmitt

During .the past five decades or so we have passed from a time when it was difficult to point to a mine or an ore body and verify that it had been discovered by geological methods, through the. Twenties when the common saying was, "Who ever heard of a mine found by a geologist?", to recent decades when hundreds of mines and ore bodies are acknowledged geological discoveries and the above query can be ignored. Recently, however, the application of mining geology appears to have been downgraded, or so it seems to me. Basic geology in mining has been cheapened and glossed over in favor of geophysics and outcrop sampling, even though the latter is merely one technique of mining geology and, to some extent anyhow, has been used for a. long time. (Locke, 3, pp 81-87). Geophysics by itself and in conjunction with geology has had success in certain geological provinces, but limited attainment in mountainous terrane except in those few cases where strongly magnetic minerals are associated with ore. Nevertheless, in the Cordillera .many experimental techniques are offered as proved ones. This is not an intent to try to depreciate honest geo- physics. Continued experimentation and use of it is approved by all, but at the same time it is foolhardy to throw mining geology overboard, Generally both approaches should be considered and usually, at first anyhow, geology is the most direct one.

Jan 1, 1960

"The mining industry suffers from a number of incorrect perceptions, one of which is that it is an outdated industry that has not changed for hundreds of years. But the truth of the matter is that mining is a vibrant, highly complex industry that not only employs highly skilled and educated professionals but is also often on the cutting edge of technology. It is an industry with projects that are ever-evolving and among the most challenging engineering feats in the world.Take for instance the U.S. 53 Highway Relocation project in Virginia, MN. While more of a civil engineering job than a traditional mining project, it is still a complex engineering challenge taking place in a mining environment that has called on the skills of eight state agencies, three federal agencies, a host of contractors and many consultants, including many from the local mining industry in the Iron Range of Minnesota.In 1960, the Minnesota Department of Transportation (MnDOT) constructed U.S, Highway 53 on a private easement owned by US Steel that cut across a massive taconite deposit. MnDOT constructed the highway with the agreement that if the highway needed to be moved to access the taconite deposit before 1987, US Steel would foot the bill. And if the move was required after 1987, the responsibility would fall to MnDOT. In 2010, MnDOT received the notice that the highway would have to move as property owner United Taconite planned to access the ore, setting in motion one of the greatest engineering challenges, and the highest risk project, in the history of the states’ transportation department.Pat Huston, U.S. Highway 53 Relocation project manager, opened the 90th SME Minnesota Section Conference in Duluth, MN on April 19 with a presentation about the project that includes 5 km (3.2 miles) of fourlane highway and a new 345-m (1,132-ft) bridge that will be the tallest in Minnesota when it is completed later this year.“This project was not business as usual,” Huston told the packed crowd. “Highway 53 connects Canada and the Iron Range to Duluth and Lake Superior. It is an important highway.”During his presentation he spoke about many topics that were familiar to the more than 1,100 mining professionals who attended the conference. In his keynote speech,"

Jan 6, 2017

By James L. Patton

Automation of mining increases the productivity of labor, thereby reducing the unit cost of labor. Such cost constitutes the largest portion of the direct or variable costs of producing coal. Therefore, any increase in productivity directly reduces variable cost. The large investment in mechanical equipment carries with it the burden of increased fixed charges. As the proportion of fixed cost to the total cost increases, the effects on the cost of production changes are amplified. Therefore, equipment must be fully utilized at all times. Averaged fixed costs rise with any decline in production. Such a situation forces coal companies to seek every means of main¬taining full production. Figure I will reflect the story on the relationship of production to cost.

Jan 1, 1962

By Michael E. Berndt

Asbestos first became an issue to Minnesota?s iron industry when it was revealed that mineral fibers similar to those in Reserve Mining?s tailings were being found in drinking water for several communities that used Lake Superior as their primary water source. This discovery turned what had largely been an environmental court battle into a case concerning public health. The courts listened to much conflicting and uncertain scientific testimony on the size and distribution of the mineral fibers and on the potential health effects imposed by them. In April 1974, the plant was ordered to shut down by a federal judge but the company quickly appealed the decision. The appeals court granted a stay and ultimately ruled that the plant?s closure could not be justified based on the unknown health effects of the mineral fibers since the consequences of such an action would have immediate and severe social and economic impacts. The plant was allowed to continue operation, but ordered to abate emissions to air around the plant and to switch to a land-based tailings disposal system. Much of the scientific uncertainty and public concern over mineral fibers in Minnesota?s taconite industry remain today. ©2007 Elsevier Inc. All rights reserved. Keywords: Minnesota; Iron ore; Taconite; Asbestos; Amphibole; Reserve Mining; Tailings; Mesabi Iron Range

Jan 1, 2007

By Ray Nivens, Umit Turunc, Caroline Sui, Nick Morrison, Douglas Steiner

"In most copper mines and concentrators, mill water is continuously recovered and reused, with fresh water added to make up for losses. When mixed, these water chemistries can lead to severe scaling, especially in pipes, tanks and pumps on the mill water supply side, reducing flows and causing significant production losses.At KGHM Robinson Nevada Mining Company, increases in the fresh water addition ratios resulted in severe scaling problems and premature pump failures thereby jeopardizing plant production. What initially appeared to be a few isolated scaling events eventually unfolded into a recurring pattern of water supply-related production losses with increasing severity. Through completion of detailed root cause analysis, chemistry modeling, laboratory work, in-plant testing and system engineering, the mechanisms of scaling were identified and addressed.Advancements in fresh water addition practices and antiscalant application methods resulted in a stepwise reduction of the mill water scaling. Cost savings and production benefits were significant to the plant’s financial metrics.IntroductionThe production of mineral and metal concentrates using the flotation process requires large quantities of water. Flotation is utilized as the primary means for beneficiation with sulfide ores. Mined ores are crushed and ground into a slurry of 20-55% solids. For each ton of ore, 400-900 gallons of water1 are needed to supply the grinding mill. Additional water is needed in the flotation circuit as well. With many modern mills operating at2 11,000-165,000 tons/day, water supply volumes can be upwards of 3,000 gpm to 100,000 gpm of flow.For plants operating at or above capacity, disruptions and restrictions in water supply flow can have a direct impact on the production and recovery of the metal. Water supply flow can be limited for a wide variety of reasons but of interest are those limitations that are due to mineral scaling. Mineral scaling is the selective point precipitation of inorganic species above saturation concentrations. Precipitated species form flow-restricting deposits in the mill water system (tanks, pumps, pipe and valves), that will eventually impact water supply to the concentrator."

Jan 1, 2017

By Robert C. Edmiston

"Further, we search for the veins by observing the hoar-frosts, which whiten all herbage except that growing over the veins, because the veins emit a warm dry exhalation which hinders the freezing of the moisture, for which reasons such plants appear rather wet than whitened by the frost," Georgius Agricola, De Re Metallica, 1556 In view of Agricola's statement, made in 1556, the concept of using the heat released by oxidizing sulfides as an ore guide can hardly be considered a product of twentieth-century technology. In fact, thermal exploration has received relatively little attention in modern times compared to other potential field geophysical methods. There have evolved, however, two basic approaches to thermal exploration for subsurface heat sources. These are 1) the measurement of surface temperatures by infrared, thermal imagery and 2) the measurement of geothermal gradients in exploratory drill holes.

Jan 1, 1974

By G. H. K. Schenck

Weather changes of a daily, weekly, or seasonal period affect mineral production and cause significant losses that are considered unavoidable. Private weather forecasting services are available on a contract basis that can significantly reduce the uncertainty associated with weather-induced changes in the production of and demand for minerals. This paper provides examples of current practice and reviews the opportunities that await those producers who incorporate weather services as an integral part of their operating, scheduling, and planning procedures. Private weather forecasts can be highly accurate because atmospheric trends such as conditions and movement tend to persist and are related to previous meteorological events. Commercial meteorological services are prepared to deal specifically with a mineral producer's special problems (Table 1). Tactical use of private forecasts is a major advance over the severely restricted value of public forecasts which, of necessity, are general in nature and cover a dispersed geographic territory. Private weather services provided on a consulting fee basis offer the mineral producer the opportunity for tactical and strategic response to weather conditions at an acceptable cost. This contrasts with the too-frequent current tendency to view weather as a random variable the costs of which are unknown and about which nothing can be done.

Jan 1, 1970

By Thomas B. Dellinger

Since 1950, rotary-drilled, large-diameter holes, "big holes", with depths to over 300 feet and diameters of over 30 inches have become numerous and widespread. Fifty such holes have been drilled for access shafts to LPG mined caverns, Over 70 holes have been drilled for various other commercial activities. Over 150 holes have been drilled by the AEC for atomic testing purposes. These holes have ranged up to 300-inch diameters with 1600-foot depths, 120-inch diameters with 570-foot depths, and 72-inch diameters with 4800-foot depths. Equipment is now available to drill a wide range of ?big holes? for varied requirements. At least a dozen drilling contractors are participating or have participated in the drilling of "big holes". The accompanying tables show pertinent historical, technical and economic data on over 250 holes. The illustrations to be presented concurrently with this paper show the various equipment and accessories now in use. (See Appendix I for captions of illustrations.)

Jan 1, 1966

By R. M. Barker

The historic Getchell property is currently being mined from the Getchell Main Underground workings, a foot wall extension of the Getchell open pit deposits along the Getchell fault. Drift-and-fill techniques are used to extract the ore through a ramp access. The adjacent Turquoise Ridge deposit is currently under development via two vertical shafts. Together, the two mines will continue to provide feed to the Getchell's 3,200 tpd mill/autoclave circuit, taking Getchell Gold from its current production rate of 200,000 ounces (Au) per annum, to over 400,000 ounces (Au) per annum by 1999.

Jan 1, 1997

By H. R. Hammond

The situation of The Consolidated Mining and Smelting Company of Canada Limited, or Cominco, may be somewhat unique in that the Company is not only a manufacturer of ammonium nitrate, but as a mining company is a major user of its own product. This situation has resulted in highly successful application of ammonium nitrate-oil explosives. Several noteworthy techniques have been developed and others have been improved. Use of this material in the mining industry has led ammonium nitrate producers to adopt the term nitro-carbo-nitrate or INN for ammonium nitrate-oil blends. A small blending plant at Cominco's largest mining property, the Sullivan Mine, at Kimberley, B.C., is producing more than 80% of all the explosive used at the Sullivan, and is supplying two other Cominco mines. Application has required intensive research to determine the best forms of ammonium nitrate for use in small holes drilled for development and long-hole stoping. It has led not only to experiments to determine the best blending oil, but also to development of loading techniques to the point where NCN is being moved through loading tubes over 700 feet. It has required research into mining practices such as hole arrangement and blasting of development cuts. It has resulted in the development of a special product for secondary breaking. All this has been accompanied by the recognition of the importance of insuring safe practices at every stage.

Jan 1, 1963

The Global Mining Standards and Guidelines Group (GMSG) is building an international, multi-stakeholder community to advance the availability and use of standards and industry guidelines for the global mining community. Standards and guidelines are key strategic tools for operational excellence, enabling companies to move forward with efficient, innovative operations with reduced risk. Launched in May 2012, the GMSG is the first international center to bring together information, resources and collaborative projects for mining standards and guidelines, in an open, knowledge-sharing forum. The GMSG is supported by five partner organizations providing outreach and helping to guide GMSG activities: the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), the Society for Mining, Metallurgy and Exploration (SME), the Australasian Institute of Mining and Metallurgy (AusIMM), the Southern African Institute of Mining and Metallurgy (SAIMM) and the Surface Mining Association for Research and Technology (SMART). GMSG was formed under the CIM Surface Mining Society, though its mandate extends to include underground mining as well. ?SME is supporting the GMSG as a key international activity to advance the implementation of standards and guidelines in our industry, and to provide a forum for our members to access, and contribute to, projects and information to assist their operations,? said SME Executive Director David Kanagy. ?We see the GMSG as a good example of ways the major mining associations can work together for the benefit of all our members.? The GMSG charter encompasses all standards and guidelines that apply to mining; however, a number of subject areas are now being spearheaded by six working groups, namely: ? Access and usage of data from mobile mining equipment onboard systems. ? Operational safety. ? Situational awareness (namely, a unified equipment operator interface). ? Underground operations. ? Asset management and operations data definitions and KPIs. ? Energy in communition.

Oct 1, 2013

By R. J. Hickson

The Grasberg copper-gold deposit was discovered in Spring 1988, just one year prior to the planned closure of Freeport Indonesia's original Ertsberg open pit copper mine. In spite of Grasberg's remote location, 600m above the Ertsberg, atop a hitherto inaccessible mountain, Freeport-McMoRan brought their latest open pit mine into production in the last week of 1989, less than two years after discovery. This paper describes the start-up of the operation, highlighting synergies drawn from both the original Ertsberg experiences and the current Freeport Indonesia underground mines.

Jan 1, 1991

By Brian Gettinger, Jared Barber, Richard Weatherly, Shannon Dunne, Jeff Masek, Chuck Wolf, Fazle Rabbi, Jack Canfield

During Hurricane Harvey over 60% of the 39 WWTPs, including the low-lying 25 MGD Sims North WWTP, and one third of the 382 lift stations owned and operated by the City of Houston were flooded resulting in extensive facility damage, loss of service and uncontrolled release of untreated wastewater into bayous and creeks. In response, the City has embarked on an effort to improve system resiliency by consolidating at-risk facilities with a network of deep sewer tunnels. These tunnels will provide secondary benefits to the collection system of augmenting the capacity of the existing 6,000 miles of sewer mains and lowering the collection system profile in poor performing areas. Investigations on the cost to mitigate the flood damages by raising the liquid stream processes at the Sims North WWTP is estimated at nearly $450 million. Instead of spending $450 million to raise the plant, the funds will be directed to providing a more robust and resilient wastewater system for the Sims basin area of Houston. The backbone of this new system is a 4.5-mile-long, 110 inch diameter deep gravity sewer tunnel that will convert a system heavily reliant on distributed lift stations to a majority gravity system with a deep consolidated lift station at the Sims South WWTP. This will also allow the City to address the flood prone infrastructure at Sims North and consolidate its operations into a single permitted outfall for this collection system. This approach is the outcome of a team effort focused on maximizing system resiliency and sustainability for the next 100 years. By thinking outside the box, the City of Houston will not only mitigate the flooding risk at Sims North WWTP, but also solve regulatory and operational challenges throughout the sewershed and deliver a winwin on multiple levels.

Jun 13, 2021