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By Otto Schumacher

Shortcut methods are commonly employed for estimating mining costs for prefeasibility studies. Most of these methods, however, are suitable for earliest stage studies or for internal discussion purposes only. The experts at InfoMine?s CostMine division recommend that any cost estimate completed for purposes of significant decisionmaking or for compliance with Canada?s NI 43-101 requirements be completed using a determinative itemized method. The same basic principles apply for an early stage, intermediate stage, or advanced stage estimate. The only difference is in the level of detail and effort employed. ? Based on the results of a completed resource estimate, an itemized cost estimate begins with development of a conceptual mine plan. Using a surface mine as an example, four elements are crucial no matter what level of study is initiated. Basic geometry of the ore deposit and waste material, with a determination of the expected ratio of waste to ore, a reasonable pit slope angle, possibly requiring the completion of geotechnical studies to predict the waste-to-ore ratio with certainty. ? Determination of the assumed ore and waste production rates. ? Locations of all ore stockpiles and waste dumps. ? Segmental haulage distances and gradients for ore and waste.

Oct 1, 2013

By Jean Rainville

Gold was first discovered in the central region of French Guiana in the mid 1860's. Production was based strictly from placer mining of the various rivers in the region. At the moment, a number of companies are actively engaged in hard rock gold exploration, concentrated in the northern and central regions of the country. The Franc-Or/BRGM joint venture in the Sophie-Repentir region of Central French Guiana offers an exceptional opportu­nity for the discovery of one or more million-plus ounce deposits of gold owing to a highly favorable structural setting in Precam­brian greenstones that host several known vein gold occurrences, some of which appear to occur near the border of a potassic granitoid intrusion. At this point in time, based mostly on predecessors' work, mineable reserves could be estimated to be in the 500,000 ounces range over the length of the property. The exploration campaign under way has the objective to delineate probable reserves of at least 2 million ounces that could be mined by open pit mining methods in the area. The program should be completed in the next 18-24 months. In order to efficiently and effectively evaluate this very large property area, all of the necessary camp, mechanical and drilling equipment has been purchased and is being transported to the property. Most of that equipment was purchased in Canada. The first drill target is the Repentir sector because of its access and the amount of detailed work that has been done by BRGM on that concession, but geological evidence suggests that many areas on the property could offer even more potential.

Jan 1, 1995

By Qiang Wang, Jiaqiang Yu, Chunhui Fan, Yong Wang, Changyu Jin, Jun Bai, Yu Lu

Accurate ore blending necessitates an in-depth understanding of movement trajectories of fragments and the spatial evolution of the displacement field in the bench during blasting, Accurate ore blending is currently one of the most complex challenges faced by mining engineers. In light of this problem, a systematic study was conducted in this paper using neural network and numerical simulation based on field monitoring data. A nonlinear mapping relationship was established between the mechanical parameters of rock mass and the displacements of the monitoring points. The measured displacements of monitoring points under blasting were input into the neural network, which used back-calculation to derive the mechanical properties of the rock mass. These parameters were then applied in a forward calculation to analyze the movement trajectory of the monitoring points. The results showed that the calculated displacements were in good agreement with the monitoring results during the. The average relative errors in the horizontal and vertical displacements were 4.12% and 15.2%, respectively. Furthermore, the muckpile profile was in an inverted recumbent “S” shape after bench blasting, which was consistent with the actual shape of the muckpile. This verified the rationality and accuracy of the method proposed in this study. Finally, the movement trajectories of particles in the bench and the spatial evolution law of the displacement field during bench blasting were determined based on the calculation results, offering theoretical support and fundamental information for accurate ore blending.

Dec 16, 2023

By Robert C. Freas

The summer joint meeting of the East Tennessee and Carolinas Sections of SME was held in Morristown, TN, on July 29 and 30, 1994. The Friday portion of the meeting began with a field trip to Asarco Inc.'s Young Mine and Mill, one of four mines operated by the company in the Mascot-Jefferson City district. The Young Mill processes ore from two other mines as well as its own, first by heavy media separation and then by standard flotation processes. Zinc concentrates are shipped by truck and barge to an electrolytic refinery in Clarksville, TN. The heavy media rejects and the dolomitic limestone tailings are sold through Asarco subsidiary American Limestone Co. Saturday's technical session, organized by Program Chairman Bob Fulweiler of the Tennessee Division of Geology, provided a review and status report of the zinc industry in Tennessee. This article summarizes papers presented, including one on recent developments in underground blasting.

Jan 1, 1994

By David E. Nicholas, Steven R. Dismuke, Paul F. Cicchini

The Buick mine, located 195 kilometers (120 miles) southwest of St. Louis in the Viburnum Trend, is owned and operated by Homestake Mining Company. The mine produces lead and zinc ore from a room and pillar mining method at a depth of approximately 335 m (1 100 ft). The Buick orebody typically averages 60 to 120 m (200 to 400 ft) in width with ore thicknesses ranging from 2.4 to 36.6 m (8 to 120 ft). The mine is divided in two; the halves are referred to as the North mine and South mine orebodies. The North mine orebody contains the higher grade ore; however, the developed reserves for the South mine orebody comprise about 60 percent of the total developed reserves for the Buick property. Existing pillars represent one-third of the total developed reserves.

Jan 1, 1986

By M. Gershon

The article is an excellent one, providing a basis for the conduct of the major tasks in underground mine planning and scheduling. I object to only one word. Since that word is featured in the title, it is a strong objection. The word used erroneously is optimization. There is no optimization performed in the article. By definition, an optimization is an approach that yields the best of all possible solutions. We can limit this definition to its narrowest sense, the optimization techniques of operations research such as linear programming, or broaden it to include less sophisticated search procedures that find the best mine plan or schedule. No such claim is made in the article. No optimization of any kind is performed. The major tool used is a simulation, which, in truth, is probably more appropriate for this problem than any optimization. But simulation does not optimize. It only allows for quick evaluation of many options, leading to the selection of the best plan "of those tried," not "of all possible plans." This article, of course, is not the first mining paper to make this error. It seems that the word optimization is used more to impress people than to refer to any act of optimizing. It is used in a way that implies "try to optimize" or "come close to optimize," but not to really do it. It is usually appropriate to quietly ignore this error. But when Dr. Chatterjee, who has done so much good work in true optimization projects and whose work I have come to admire, makes such an error, it is time to publicly dispute it. Having discussed this very point with him in the past, I am sure that he will agree. If he can support this position in his response, perhaps people will start to listen and we can reduce the number of false claims of optimization. This should be easy for him in this case since the approach he used, simulation, is the more appropriate one anyway.

Jan 1, 1987

By G. Wang

With the depletion of easy-to-treat phosphate resources, low quality phosphate ores with high carbonates, particularly dolomite impurities have to be mined to meet the agricultural demand because of the continued growth of world population. The separation of dolomite from phosphate has been recognized as one of the most difficult subjects in mineral processing due to the similarities in their physical and chemical properties. Flotation is considered the most important approach for beneficiating both easy-to-treat and high impurity phosphate resources. There is no doubt that the development of reagents is the key for achieving satisfactory separation performance through flotation process. In order to separate dolomite from phosphate, Arr-Maz Custom Chemicals has made great efforts in developing flotation reagents for removal of carbonates from phosphate ores of different origins worldwide. This paper describes some flotation reagents and processes for the separation of dolomite or/and calcite impurities from phosphate in the ores from different locations.

Jan 1, 2010

By Ben Sosewitz

The subject of rapid excavation tunneling is one that is extremely important to the people in the Metropolitan area of Chicago. My personal observation is that it is also extremely important to the urban communities around the U.S., to many local and state governments, and to the public officials who are deeply concerned about state affairs and taxes. The Metropolitan Chicago area is in fact, (as are 40 other major urban areas in the U.S.) confronted at the present time with a very serious combined sewer overflow, drainage and pollution problem which accounts for an estimated 40% of the pollutional load on its waterway system. In response to this the District has to date spent some seven millions of dollars in an attempt to find the most economical solution available for the elimination of this problem. This study included extensive investigations of the geological strata, the quantity and quality of storm runoff to be dealt with, and the various methods of storage and treatment available. It has considered solving the overflow problem by a concept involving a series of tunnels, rock tunnels, shafts and storage areas which will collect, retain and subsequently treat that portion of the combined sewer overflow which can be handled in the most cost-effective and economical way, consistent with following the federal and state standards - with which we at the present time agree in principle.

Jan 1, 1997

By J. Sidhom, W. Fourie

"As the mining industry continues to face difficult challenges the need to persistently focus on productivity and utilization of labor and equipment costs will intensify. With these challenges in mind, Joy Global is helping to bring mining performance and analytics to the next level. By evaluating underground haulage, a significant component of the Room and Pillar mining value stream, variables have been identified and sensitivities have been performed to show opportunities to balance and streamline throughput. As a result of applying operational excellence tools to the mining environment, Joy Global is seeking to optimize mining performances by limiting waste, simplifying the process, increasing productivity and machine utilization, as well as removing workers from harm’s way. These days it’s not enough to work harder; mines have to work smarter. Improving efficiency, reducing costs, increasing safety: these are no longer ‘nice to haves’, they are ‘must haves’. Starting with the best products and the right people is a first step, but then what? How do mines take their operations from just OK to being a top performer? By using operational excellence principles aimed at eliminating waste, simplifying processes, automating where possible and removing people from harm’s way. The fundamentals of operational excellence (OpEx) are based upon the DMAIC process, which stands for define, measure, analyze, improve and control. DMAIC is an improvement cycle that helps with, for example, haulage optimization by: defining the issues and problems in the process as well as the areas of improvement; measuring and collecting mining operational data by time study and equipment monitoring system; analyzing through sensitivities and production modelling to determine root causes; then improving the performance and controlling the operation. Joy Global uses Joy OpEx or ‘lean’ principles inside its organization to drive efficiency, but it also helps its customers employ them to achieve new levels of productivity and safety. These same principles can be applied in most situations to streamline processes, improve operations and deliver value. As applied to mining, OpEx is seen as moving the needle on value creation by first identifying the value stream, then analyzing the areas that are not optimized. Once defined, these areas are ‘designed out’ of operational processes to create an automated operational flow. At a US coal mine, Joy Global was brought in to apply Joy OpEx principles to optimize mining and haulage to improve productivity and reduce costs. This multi-phase process started by defining the existing systems challenges to start finding areas for improvement."

Jan 1, 2017

By A. B. Cortes

This research work discusses the development of a two-dimensional model that represents the flow that occurs in the inlet section of hydrocyclones. The governing equations are the two-dimensional, unsteady, incompressible Navier-Stokes equations in cylindrical polar coordinates with primitive variable formulations. In this approach, no assumptions have been made other than independence in the axial direction. The full two-dimensional Navier-Stokes equation in the r-a plane is used. The commonly used simplifying assumption of axisymmetry is not used. A numerical technique based on a newly developed spectral-difference method is used to solve the equations. The spectral-difference method is a multi-domain, and multi-dimensional extension of the Jacobi polynomial collocation technique. The computational grid for the inlet section is composed of 25 sub-domains which result from five partitions in the angular direction and five partitions in the radial direction. Several test cases are used to validate the appropriateness of the numerical model.

Jan 1, 1995

By Edward C. Mabbs

U.S. industry must increase its productivity or lose its competitive position in the rapidly expanding and inter-dependent world markets. Recent improvements in material handling techniques and equipment, coordinated with production processes, provide one of the greatest opportunities to increase productivity. Successful managers must learn how to take advantage of these material handling opportunities to gain competitive position.

Jan 1, 1973

By C. Heckman, M. S. Moats, A. Luyima, W. Cui

"Cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and galvanodynamic and chronopotentiometric techniques were used to characterize the effects of DXG-F7®, a commercial smoothing agent, on copper electrodeposition onto 316L stainless steel from a synthetic electrolyte containing 40 g/L copper (Cu2+), 160 g/L sulfuric acid (H2SO4) and 20 mg/L chloride (Cl-) at 40oC. The findings were compared against results using HydroStar® 4208, a modified polysaccharide. The nucleation overpotential and plating potential observed in cyclic voltammetry and galvanodynamic testing showed that neither DXG-F7 nor HydroStar significantly polarized acidic copper electrodeposition. Subtle differences between the additives were found during EIS testing and modeling, but more research will be needed to fully understand these differences. Surface-roughness measurements of two-hour deposits indicate that DXG-F7 and HydroStar produced smoother deposits as their concentrations in the electrolyte increased. No difference in the surface roughness of deposits was detected between the additives. Based on the experimental evidence resulting from the laboratory testing, no significant difference was found between DXG-F7 and HydroStar at 20 mg/L Cl- concentration, with the exception that DXG-F7 dissolves more easily in water than HydroStar. Introduction Cathode deposits obtained from acidified copper sulfate electrolyte(s) without organic additives are often soft, coarsely crystalline and nodular (Sun and O’Keefe, 1992). Therefore, small amounts of organic additives are added to the electrolyte to produce level and dense cathodes during copper electrowinning. The action of organic additives is thought to be due to their adsorption on the surfaces of the newly formed copper grains. Hence, any copper grain that grows excessively fast adsorbs a layer of organic additive, which inhibits growth. The result is a smoother and harder deposit of suitable purity (Sun and O’Keefe, 1992). In part I of our four-part series on the examining of copper electrowinning smoothing agents, a review of previously published work on organic additives used during copper electrowinning was presented (Moats, Luyima and Cui, 2016). In the review, it was noted that many tankhouses had switched from guar to other saccharide-based products such as HydroStar and DXG-F7."

Jan 1, 2016

By George W. Leney

The iron ore industry might justifiably claim to have originated the science of geophysical prospecting. Their use of geophysical methods was probably the first application of these scientific techniques to the search for economic materials although the exact origin is undoubtedly lost in the unrecorded observations of. some prospector experimenting with compasses or bits of lodestone. Since 1879 when Thalen published "On the Examination of Iron Ore Deposits by Magnetic Measurements" these methods have been a standard supplement to other prospecting techniques. However, many of the great ore bodies of the Precambrian iron ranges were not particularly suitable for geophysical work. The ores were oxidized and enriched through leaching of silica so that they were nearly non-magnetic and other physical properties which distinguished them from the wall rocks were largely destroyed. With the gradual exhaustion of these high grade direct shipping ores, and ores that could be beneficiated by simple means, the iron ore industry turned initially toward the importation of similar high grade foreign ores. At the same time, new processes for concentrating lower grade materials were being developed and older ones improved upon. These concentrates' when pelletized produced such important savings in blast furnace hot metal costs that they now command a premium in the iron ore market and have weakened the competitive position of the remaining high grade ores. The ore bodies now being sought are usually unoxidized and frequently they are also metamorphosed.

Jan 1, 1965

By William S. Brack

The mining industry is very capital intensive. Competition for shareholder investment has never been greater. Among our challenges is the need to meet shareholder expectations (return on investment), and one area of focus lies in our ability to deliver value on our capital investments. Our ability to meet project expectations affects not only the economics associated with the immediate project but also directly influences our ability to finance future projects. Moreover, our ability as individual companies to attract investor capital is influenced by how we have done overall as an industry, and our industry track record has not been that stellar. With safety, scope, cost, schedule, and quality as guiding principles, our project managers today must address high expectations on every project. This paper examines some items that should be on today's project management checklist. PROJECT ENGINEERING Herbert Hoover, himself a mining engineer, said Engineering is a great profession. There is the fascination of watching a figment of the imagination emerge through the aid of science to a plan on paper. Then it moves to realization in stone or metal or energy. Then it brings jobs and homes to men. Then it elevates the standards of living and adds to the comforts of life. That is the engineer's high privilege.

Jan 1, 2004

By Peter Schmäh

Pipe-jacked tunnels are considered for a large variety of applications from water and sewage, cable ducts to challenging pipeline crossings or landfall construction. In most cases, Slurry MTBMs are used to carry out these projects. Continuous further development of technological features for pipe jacking plays a key role to overcome feasibility limits and to meet increased project requirements. As tightened safety regulations in terms of accessibility and escape routes increasingly limit the options of small segment lining tunnels in the diameter range below 4 m, 13 feet, pipe jacking has partially taken over. During the last decades, a growing number of large-diameter and long-distance pipe jacking projects have been completed. Experienced contractors successfully use the technological capacity of the MTBM equipment. The machine and cutting wheel have to be designed according to the ground conditions. Bentonite lubrication and interjacking stations are key factors to keep push forces moderate. For long pipe jacking drives, a so-called push module can be installed in the machine can, to be able to switch from pipe jacking to segment lining in case the machine gets stuck. The overall aim is to provide clients and the tunnel construction industry with safe and economical solu- tions for successful project execution. This presentation will present international milestone projects and will also discuss the latest developments in automation, related opportunities and limitations, and the future of digitization and artificial intelligence in pipe jacking.

Jun 23, 2024

By Bjorn Olsson

"Heavy impact. High frequency hammering. Extreme abrasion. Building on the experience of owning and operating its own mines, Ovako has developed a deep knowledge of how vital the right steel properties are in withstanding the extreme loads encountered in every part of the drill string. That is why Ovako’s product development process is focused on understanding the specific load cases and manufacturing operations associated with rock tools.The punishing conditions of percussive drilling can push the limits of most materials. And heavy mechanical loads are only the beginning. Highimpact energies at high frequency are a major source of fatigue. High temperatures result from impact energy losses. And abrasive, erosive and adhesive wear are constant risks. Handling any of these varying demands at a single point along the drill string is difficult enough — which makes optimizing for the entire drilling system an extremely complex challenge. Engineering for specific loadsOvako has specialized over many decades in analyzing the dominant loads for each of the parts and components used in rock tools, and testing for individual applications in its laboratories. The most critical fatigue properties are controlled through the steel metallurgy, and supported by performance measurements through extensive rotating bending fatigue (RBF) testing, along with special methods that combine impact load with various wear loads. The result is a fit-for-purpose steel with tightly controlled performance properties, making it possible for customers to precalculate the expected life time of their components for highly automated and repetitive processes Tailoring steels for the processing route.The same levels of control and predictability must be carried through to the customer’s own manufacturing processes. By ensuring minimal variations in chemical composition, everything from heat treatment and welding to automated machining can be carried out with high consistency. With precisely controlled material properties based on an existing processing route and exact load case, customers are able to minimize their total tool production costs while ensuring optimal performance for their end products. Development of Hybrid SteelBuilding on this experience in the mining industry, Ovako has developed a new steel family, known as Hybrid Steel, designed to meet the demands of high-stress, elevatedtemperature applications where mechanical and fatigue strength are critical. Traditionally, steels for these applications are produced by expensive small-batch processes. Hybrid Steel, however, enables high volume production at a competitive cost.The world of steel has traditionally been divided into clearly separated categories of tool steel, stainless steel and lower alloy engineering steel. Hybrid Steel is now challenging that division, offering attractive properties from all three categories."

Jan 12, 2017

By Timothy J. Haddon

For the mining industry in general and gold mining in particular, the past few years have been difficult. Economic conditions, coupled with growing regulatory restrictions, have led to increasingly important reasons for managing assets wisely. From a public company perspective, such asset management makes sense because it ultimately provides for an increase in shareholder wealth, and that is why we are in business. Regardless of whether a company is public or not, assets must be managed effectively to remain a player in today's competitive environment. So, as the chief executive officer of a gold mining company, how do we manage our assets to ensure that we are satisfying our obligations to our customer-the Amax Gold shareholder? The gold industry has been under siege. We have just completed the third year with average prices below $12.85/ g ($400/oz). When finding, and/or acquisition costs and development costs to operating costs are added, there isn't much of a profit margin left. What this environment provides, however, is opportunities for growth. In the gold business, you either grow or you die. Today, most North American gold producers have, at most, a 10-year mine life. We are all scrambling to add reserves so we do not become extinct. As prices remain low, opportunities abound for increasing diminishing reserves. This is the time for the opportunistic company to take advantage of market conditions and that is precisely what Amax Gold has done. There are six components to running a successful gold business: • finding reserves through exploration, acquisition or joint venture, • financing the project, • permitting and constructing the project, • operating the project, • cash management and • communication.

Jan 1, 1992

By Steven B. Van Kouteren

Value added is a loosely used qualifier in the industrial minerals industry. What exactly does it mean? What does it take to make a value-added product? More importantly, how does a company maintain the value added to its products? Most people agree that value-added means the value of a mineral minus the cost to produce it. This is misleading, though, because producing value-added products does not necessarily guarantee the profitability of the products. In some cases, firms that make value-added products are not very profitable. It is important not only to understand how to make a value-added product but also how competitive forces in the market can erode the value added. Therefore, when looking at value-added opportunities, producers must understand how to obtain the value added and how to maintain that value. Four major factors limit a company's ability to add value to its products. This paper examines these factors. It uses the ground calcium carbonate and mica industries as examples.

Jan 1, 1990

By K. Terhaar, K. Prisbrey

The objective was to determine operating protocols for a lead and silver column flotation cleaner being considered for installation at Sunshine Precious Metals Inc. 's Kellogg mill in Northern Idaho. In this column, tetrahedrite and galena were floated, and pyrite and other gangue minerals, including siderite and silica, were depressed. The procedure was to develop a dynamic simulation using a linear transfer function approach. The transfer function related cause-and-effect variables such as the influence of collector and depressant dosages on recovery and grades. Bench-scale flotation tests followed by pilot column testing provided the data used to develop a linear transfer function. The transfer function was derived using a spreadsheet. This model was applied to simulate how the flotation column could be made to respond to disturbances in feed grade. The results were that xanthate, zinc sulfate and sodium cyanide were found to be suitable controls for grade and recovery. Simulations showed the best sequence of manipulations of these reagents, and these sequences are useful for future operator training. The conclusion was that linear transfer functions were able to simulate lead and silver recovery, develop scenarios for operator training and provide a foundation for future on-line control.

Jan 1, 2002

By Kerry Spickelmier

A traveler driving across desolate central Nevada to the Round Mountain property can easily identify with turn- of-the-century prospectors seeking a fortune, or at least an existence, from the high desert. But now a shadow passing overhead is as likely a sophisticated fighter aircraft from Stillwater Naval Air Station as a circling bird, and the famous trails west show only as historical markers along the highway. Even the approximately 400- km (250-mile) trip southeast from Reno or northwest from Las Vegas takes hours now, not days. And the camps of Round Mountain’s early prospectors have been replaced by one of the world’s largest gold heap-leaching operations. While Round Mountain’s uniqueness begins with its scale, it doesn’t end there. Consider the mine’s low cutoff grade of 0.2 g/t (0.006 oz/st) gold, made possible by a new dedicated (not reusable) leach pad. Also, the operation’s degree of automation means that ore dropped in the south crusher system is not manually handled until it is stripped from the pads. There is the bonus of a geothermal field that is tapped to heat the leach solutions in the winter. And, of course, there was that “unexpected” hitch expected in all mining operations. For Round Mountain, it meant buying a gravity plant to process the gold nuggets discovered last summer in a fault gouge.

Jan 1, 1993