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By Wi11iam I. Rau

In the recent past, there have been numerous projections of the capital requirements for additional mine and processing capacities required to meet projected non-Communist World demand for minerals during the next 15 years. A consensus judgment would place this currently at $14 billion per year, with the largest expenditures required for increases in aluminum and copper production. Until the early 1960's, internally-generated funds were used to finance nearly all of the large mining companies' capital requirements. Since that time, however, the enormous rise in capital costs per ton of capacity, accompanied by a relative stagnation in the financial condition of many of the major mining companies, have caused the industry to begin to rely on external sources for financing expansion, most notably, project financing from commercial banks and institutional lenders. Seven years ago, it was estimated that, in the five-year period 1972-1976,75% of the total capital requirements of $10 billion per year would come from internally-generated funds, with the balance to be provided by external sources. l There is little doubt that, in the coming decade, the percentage provided by external sources will increase. There should be little difficulty in attracting the necessary investment within the U.S., particularly in view of the expected continuation of companies in diverse industries seeking mineral investment opportunities. The more serious question lies in the availability of internal and external sources of funds for the expansion of mine and smelting capacity in the developing countries. Recently, R. F. Mikesell projected an average annual investment of $4.7 billion (in 1977 prices) over the 1977-1990 period would be required from foreign sources to expand metal producing capacity in developing countries. Mikesell concluded that external financing of mining projects in the developing world has averaged less than $1 billion per year over the past five years, thereby requiring more than a quadru1ling of this financing over the next decade.

Jan 1, 1978

By Jeff Fontana, Daniel Ebin, Eric Westergren, William Currier

The PMott MacDonaldlane Train Tunnel West Extension (PTTWE) Project at HartsfieldJackson Atlanta International Airport includes the extension of the existing automated people mover system and terminal renovations at the baggage claim station. To assist with design, pricing, and assessment of risk on this progressive design-build project, 3D design models were prepared to increase visibility into realities of construction. This paper will focus on the original intent of the models and explore the additional, unforeseen value they provided throughout the design and construction process.

Dec 1, 2022

By Paul D. Tomlingson

The difficult and often harsh working environment of the mining industry can stress both personnel and equipment to the extreme. Often, the unintended consequences of this environment lead to confrontations between departments, as each goes about its tasks of mining, maintaining or supporting these activities. On occasion, the confrontations may result in criticism of other departments for perceived or real sins or omissions. The offended department may not be able to change the circumstances, but can only complain while frustration persists. The most effective solutions are the actions of the mine manager. By establishing mutually supporting roles of each department and specifying conditions for the interactive conduct of maintenance, the mine manager can better assure that the inherent problems of the mining environment are neutralized.

Jan 1, 2011

By Louis M. Perlman

Quantitative methods are, by now, a standard tool of the mining industry, and are commonly used by Research Departments in their evaluation of production methods and schedules, and their associated costs. Indeed, much sophisticated computer work has been devoted to such evaluation of controllable costs and capital requirements. These data are an important input into the project evaluation formula, which is probably the most important single calculation per formed by a mining company, since the result decides whether a particular project is viable. It is instructive to summarize the broad principles of project evaluation, since they are crucial to the remaining sections of this paper. PROJECT EVALUATION The most widely used method of appraising projects is known as Discounted Cash Flow (DCF) method. Two main variants are used; they are known as the 'not present value' (NPV) approach and the 'internal rate of return' (IRR) approach respectively. The difference between the two is that the former takes the firm's interest rate as given and uses this knowledge to calculate the present value of the project; whereas the latter calculates the highest interest rate the project could tolerate and still just breaks even. The technique is more simply discussed in terms of the first method (NPV).

Jan 1, 1972

By Bruce Hern

The last 10 years have seen a dramatic increase in the requirements for product coal quality control. This has led to electric utility sulfur scrubbing, metallurgical blast furnace optimization and coal producer blend and yield optimization. To achieve this improved level of control, coal producers are designing facilities that emphasize new technology. New facilities will be designed and existing facilities will be retrofitted with state-of-the-art technology to meet quality control standards that are dictated by the market. The first step in designing for process control requires the identification of those parameters to be controlled and the upsets that can cause variances in the final shipped product quality. The most common parameters that require control are the surface moisture (%), ash (%), pyritic sulfur (%) and gross calorific value (Btu). Total moisture is that moisture that exists on the surface of the particle and is inherent in the particle itself. For the purposes of control, the total moisture is monitored, while surface moisture is controlled. Ash is the inorganic residue remaining after all other constituents are burned away at 75O°C( 1382°F)(ASTM, 1992). Sulfur is the amount of total sulfur that exists either as pyrite (FeS2), inorganic sulfate (FeS04), or organic sulfates (C4H4S) (Leonard, 1979). Currently, pyrite is controlled and total sulfur is monitored. The gross calorific value is the amount of heat produced when a unit quantity of coal is ignited under specified conditions. In this case, a l-g (0.03-oz.) sample of coal is ignited in an isoperibol waterbath and the temperature rise of the water bath is observed. The moisture and ash-free (MAF) Btu is relatively constant for a given seam, resulting in the whole calorific value being a function of the moisture and ash levels (Leonard, 1979).

Jan 1, 1994

By J. Slivnik, A. Stergarsek

[The site] [Z]irovski vrh uranium ore deposit is located in the extreme north-western part of Yugoslavia, some fourthy kilometers from the capital of Socialist Republic of Slovenia, Ljubljana, not far from the Italian and Austrian border. The sandstone type deposit of uranium ore with medium grade is located in a foothill of Julian Alps. The site shows some typical conditions for this region, which demand special attention in respect to the incorporation of an uranium treatment facility into environment. Among these specific conditions the following site characteristics should be mentioned: - populated area of agricultural and recreational value, - unconvenient climatic conditions with excessive rainfall and long lasting temperature inversions in the winter time, - very pure surface and underground waters which supply the drinking water reservate for large area including the capital of Slovenia, - sharp relief, - unconvenient geological structure. The choise of technology The intention to produce uranium and at the same time respecting the natural characteristics and existing uses of the site made the design of the ore treatment facility relatively difficult one. In general, there were two basic alternatives available perform the task. First alternative was to adopt the usual technological flowsheet with wet tailings disposal and with discharge of used water i.e. liquid effluents into the river. In order to prevent the negative impact of such technology on the sourrounding area sophisticated water purification installation and costly measures in wet tailings disposal e.g. impermeabilisation of large areas by concrete injections, large dam constructions, uncertain capturing of the water sources should be employed. Second alternative was to modify the usual flowsheet by employing the maximal recycling of liquid effluents to the process and to dispose the solid

Jan 1, 1980

By Kevin Schraden, Andrea Pezzi

environmental and social/political changes the world is currently experiencing. Three of major challenges facing the mining industry today are: water scarcity, unpredictable weather conditions that generate a risk of tailings dam failures as well as the correlating social pressure and government regulations that prevent the development of new or expanded tailings dam projects. It is estimated the total number of active, inactive and closed storage facilities globally is over 8,500 containing over 217 km3 of tailings (46% are from copper mining)1 which at some point will need to be addressed. Technologically, there are several solutions for tailings management, including conventional ponds, thickened tails, paste backfill and filtered dry stack tailings. The use of pressure filters, for tailings dewatering is currently being evaluated and often selected as the preferred technology where dry stacking is the chosen solution for residue disposal. This is mainly due to the pressure filters ability and flexibility to address and achieve the current challenging aspects of tailings processing including: • Extremely high capacities of >80,000 dry tons/day • Lower ore grades which require finer grinding and result in a higher amount fine fractions and clay content • Residual moisture targets required for the geotechnical specifications for dry stacking

Feb 1, 2024

By Fabio Mielli

Encompassing between 20 and 40 percent of the typical mining operational costs, energy in mining operations is a growing concern for the industry. However, this concern is a complex, multi-faceted variable that involves government regulations, societal pressures, cost and competitiveness. Managing energy efficiency is becoming a keystone of successful companies. The suggested energy strategy in mining and mineral processing operations must follow a well-structured approach to include the following: ? Understanding where energy is being used and why. ? Recommending and implementing energy conservation measures. ? Driving visibility to targets and results. ? Leveraging the energy spent across the enterprise. ? Developing a robust energy and sustainability strategy. Additionally, it must ensure that all decisions support the financial and operational integrity of the business.

Jan 1, 2012

By W. C. Lacy

It is the responsibility of educators to look ahead and prepare young engineers and scientists to cope with industrial and social problems of the future. We are faced with a review of history as well as prophesy of the future. The mining industry exists in a "bubble" with little interaction or communication with the outside. This isolation must be broken down if the industry is to survive in the U.S. and Canada. The ability to communicate with the general public and public officials is essential. Many changes are occurring that will require readjustments in technology and staffing. Aging population will result in raising retirement and increasing available workforce. This may force shorter working weeks to supply additional jobs. Environmental concerns will likely direct more attention not only to these concerns during mining, but to planning for post-mining land usage. Retraining and up-dating educational programs are required to cope with these changes.

Jan 1, 1994

By T. R. Ley

"RELIABILITY & SAFETY – TOGETHER. REALLY? I was starkly reminded of the challenges facing by the coal industry while talking with a number of senior mining executives. One said to me: “Safety is the #1 priority in our organization but of course, dollars are very, very important!!!” A coal mine worker at the Bluefield Coal Show claimed: “We know our equipment is bleeding hydraulic fluid all over the place but all that matters is getting the coal out”. We all understand. We want our people to go home safely at the end of the day but the coal industry is bleeding – fluids, dollars and real blood. An issue getting plenty of buzz these days is equipment reliability – in mining too! Achieving an optimal return from the massive investments in equipment is a critical requirement for success within a capital intensive industry like coal mining. You can cut costs by scrimping on maintenance, scavenging used parts and downsizing. Or, you can save money by being smarter with your asset management processes. Can we afford to spend money on both safety and reliability? Is one more important than the other? Many leading edge companies from a variety of industries will tell you that you can’t just cost-cut your way to profitability - or even survival. You need to systematically improve the effectiveness of your business. Do reliability and safety both have a place in improving the performance of the coal industry? According to Ron Moore, of The RM Group, the answer is emphatically YES! Ron says: “If you believe in safety, then you MUST believe in reliability and, more importantly, have the appropriate policies, systems, practices and measures in place. If you want lower costs, you must get your processes right. Simple cost cutting will remove resources from your system without changing the underlying system design, and performance will likely deteriorate.” Figure 1 shows the 5+ year results of a large manufacturing company. When plants are running well (high Asset Utilization), then injuries are less likely. Figure 2 plots data from a number of manufacturing plants. If you want sustainably lower costs get your reliability processes right. But these are manufacturing companies, not coal mining operations! It doesn’t matter. The fundamentals still apply. Mining industry thought leaders tell us that manufacturing is 20-30 years ahead of us and we need to learn from them – and do so quickly. Leading companies, no matter the industry, think in terms of operational excellence. They see this as the meshing of people, process and technology to achieve optimal results. Safety and reliability go hand-in-hand. People and equipment are different – but only to the extent that each requires its own relevant, but related, policies, practices, systems and metrics to achieve effective performance."

Jan 1, 2016

By Kelly Sands

"Mitigation may be considered a hurdle when it comes to environmental permitting. For complex projects with site specific mitigation plans, the time to devise those plans and get them approved can be a long and costly endeavor. However, mitigation options are expanding and the mitigation banking industry has grown tremendously over the last two decades, helping projects move forward with less debate. Mining companies are recognizing the value that mitigation banks provide in helping to shore up project timelines and costs. Where possible, companies are taking advantage of the opportunities to buy credits from thirdparty providers offering mitigation bank credits. In some instances, mining companies are taking matters into their own hands by establishing mitigation banks to realize their own mitigation freedom. That can have its advantages and disadvantages, as discussed below. All in all, the expansion of mitigation options has streamlined the permitting process, introduced flexibility, improved project permitting timelines and loosened the permitting girdle.Compensatory mitigationCompensatory mitigation involves actions taken to offset unavoidable adverse impacts to wetlands, streams and other aquatic resources and authorized by Clean Water Act section 404 permits and other permits. As such, compensatory mitigation is a critical tool in helping the federal government meet the longstanding national goal of ‘‘no net loss’’ of Waters of the U.S., both in acreage and function.Section 314 of the National Defense Authorization Act for Fiscal Year 2004 required the Secretary of the Army, acting through the Chief of Engineers, to issue regulations “establishing performance standards and criteria for the use, consistent with Section 404 of the Clean Water Act, of on-site, offsite, and in-lieu fee mitigation and mitigation banking.” The provision also required that those regulations ‘‘maximize available credits and opportunities for mitigation, provide flexibility for regional variations in wetland conditions, functions and values, and apply equivalent standards and criteria to each type of compensatory mitigation’’ (73 FR 19595). The result was the Final Rule on Compensatory Mitigation for Losses of Aquatic Resources issued in 2008 (33 CFR Parts 325 and 332).”"

Jan 6, 2017

By Jean-Michel M. Rendu

Increasingly, geologists use geostatistical methods to evaluate drilling programs. The complexity of the methods varies with the nature of the available sample information, the objective of the statistical analysis and the geologist's experience. Occasionally, estimating the average sample grade is all that is required. In other instances a semivariogram calculation may be considered. If sufficient data is available, the geologist may wish to estimate blocks or panels of complex shape, using the kriging method of evaluation. Historically, the use of geostatistics by geologists has been limited by a number of factors, most significant being the difficulty in accessing and using computer programs needed to complete the necessary studies. Geologists are often working in remote areas from which electronic communication is unreliable, if not impossible. Even when access to computer programs is technically possible, the costs incurred in accessing and using these programs are often considered prohibitive. In many instances using the programs requires an understanding of computer systems far beyond that which a field geologist can justifiably be interested in acquiring and maintaining.

Jan 1, 1984

By Chee Theng

"Getting minerals out of ores is messy, but mineral processors learn to have fun with it. Celebrating the innate joys of the industry was the theme of this year’s Colorado MPD Conference. At the same time, attendees dug deeper for insights into problems that continue to dog the community, including tailings dam crises, water resource challenges, and a dwindling number of academics to teach and train the workforce (see box).Tailings dam crisesMatt Fuller of Tierra Group International Ltd. brought some of the audience to tears with his impassioned talk on “The Infamous Legacy of Upstream Tailings Dams,” which won the conference’s Lou Cope award for best paper. The talk was especially poignant coming on the heels of the January tailings dam failure in Vale S.A.’s Córrego do Feijão iron ore mine in Brazil, the latest in a series of catastrophic dam failures over the past decade that includes the Fundão dam failure in 2015.Noting that the two dams share a common characteristic — both are upstream tailing dams — Fuller explained the three basic dam construction methods and why certain upstream tailing dams are susceptible to failure (Fig. 1). The downstream, centerline and upstream methods denote the direction the centerline of the dam crest moves with each successive raise in elevation of the dam. With the downstream dam, the foundation for future raises is essentially the same as that of the starter dam, he explained. With the centerline dam, half of the dam is constructed on the same foundation as the starter dam, and with the upstream dam, each successive raise is built out over the top of the tailings.“Downstream dams are expensive to build because each successive raise is bigger, so the sustaining capex to build them keeps growing,” Fuller said. Many decades ago, mine owners realized they could construct a starter dam, put their tailings through a hydrocyclone, generate a coarse sand fraction and stack the sand over the top of the tailings to build the next raise. “Then, there is no sustaining capex, it all comes out of operations,” Fuller added. The footprint is smaller, and it is a favorable means of retaining the tailings."

Jul 1, 2019

By Donald Towse

Portland cement is a basic building material in every country in the world, and, fortunately, the raw materials required in its manufacture are widely distributed. It is a low-priced bulk commodity (price one cent a pound or less, with a density of 100 pounds per cubic foot.) Table 1. Approximate price per pound of selected mineral products. Copper 48 cents per pound Aluminum 27 Lead and zinc 15 Asbestos 3 to 18 Pumice 6 Sulfur 2 Bauxite (abrasive) 1.8 Barite 1 to 1.6 Cement 1 Primitive regions may get along without any Portland cement, but most countries use some, and it is one of the most widespread building materials, even if used in small quantities. Use of cement begins early in a country's development, and, because of local availability of raw materials, cement manufacture is one of the first heavy industries many countries desire. Use and manufacture of cement usually precedes other industrial materials such as steel and heavy chemicals, and consumption levels off for a long period during development of infrastructure and an economic base. With a mature economy comes a very high consumption. Per capita consumption varies ten times or more between nations (Figure 1).

Jan 1, 1970

By R. L. Miller

Two samples of iron enriched basalt (IEB) containing simulated nuclear fuel and having two distinct microstructures were prepared and tested for uranium recovery. The IEBs are refractory towards leaching by ground water. However, the uranium content (15.8%) is high enough that if aggressive leaching techniques are used for uranium recovery, these materials could be considered as man-made uranium ores. The IEBs discussed in this report were prepared to simulate Three Mile Island-2 core debris. The crushed IEBs were treated using three different methods simulating potential industrial scale processes. In one method the IEBs were fused with sodium hydroxide then the cooled mass leached first with water then with dilute sulfuric acid; about 52% of the uranium was recovered in this case. In the second method the IEBs were treated with a sulfuric acid/hydrogen peroxide lixiviant and about 13% of the uranium was recovered. In the third technique the IEBs were leached with a sodium carbonate/sodium bicarbonate/hydrogen peroxide solution. Only about 0.1% of the uranium was recovered. The results of these screening tests suggest that the IEBs can be successfully treated for recovery of the contained uranium. Other studies would be required to determine if other values, such as zirconium or silver, could be recovered from the IEBs.

Jan 1, 1984

By Felicia F. Peng

Flotation process is particle hydrophobic surface-based separation technique. To improve the essential flotation steps of collision and attachment, and reduce detachment probabilities between air bubbles and hydrophobic particles, a selectively designed cavitaion venture-tube can be used to generate very high numbers of pico-nano bubbles to flotation column. Fully embraced by those high numbers of tiny bubbles, hydrophobic particles are readily attracting those tiny bubbles to their surfaces. The results of column flotation of Pittsburgh No.8 seam coal are obtained in a 50 cm ID and 162cm height flotation column equipped with static-mixer and cavitation-venture tube, using kerosene as collector and MIBC as frother. Design of experiment procedure combined with statistical two-stepwise analysis method are applied and attempted to made the optimizing the grade and recovery. The effect of independent variables on response has been explained. Combustible material recovery of 85-90% at clean coal product of 10-11 % ash are obtained from feed of 29.6% ash, with reduced amount of frother and collector than that used in conventional column flotation. The column flotation process utilizing the pico-nanobubbles can also be extended to the lower limit and upper limit of particle size ranges for better recovery minus 75 µm and 300-600 µm, respectively.

Jan 1, 2013

By J. P. Morgan

The Vesta Preparation Plant of the Jones & Laughlin Steel Corporation is located on the Monongahela River, eight miles south of Brownsville, Pennsylvania. This plant is capable of cleaning 2400 NT/hr of a mixture of Pittsburgh seam high volatile coals from the Vesta and Shannopin mines to produce a metallurgical coal of 6.75% ash and a steam coal containing 14% ash. Heavy media vessels are utilized to upgrade the coarse coal while launders and tables. handle the -1/4" fraction of the raw coal feed. Cleaned -coal goes to boot classifiers where the +48 mesh material settles and is removed by bucket elevators. This 1/4 x 48 mesh material is then sent to centrifugal driers for dewatering. As designed, the minus 48 mesh fraction overflows the boot as a 7 to 8% solids slurry and is recovered by cyclones and a thickener and dewatered by filtration. The-products of the heavy media circuit, the launder-table-boot-drier circuit and the cyclone-thickener-filter circuit are combined to constitute the shipped metallurgical coal. This Vesta-Shannopin mix is combined at J&L's Pittsburgh and Aliquippa Works with purchased low and medium volatile coals for the production of metallurgical coke.

Jan 1, 1962

By Stanley J. LeFond

After two disappointing years where most industrial minerals posted decreasing production, 1981 saw an increase in production over 1980, or at least in status quo. Several commodities did, however, post significant gains. For example, bromine posted a 14% increase; fluorspar production dropped 21% in 1980, but gained 24% in 1981; and sulfur production increased. However, perlite was off 13% and manufactured sodium sulfate off 18% in 1981, while natural sodium sulfate production remained almost even with 1980. In fact, many industrial minerals production either remained constant, increased, or decreased only slightly over 1980. Increasing energy costs had their impact on industrial minerals in 1981. Hopefully, the recent downward trend in energy costs, at least gasoline, will financially help some of the more marginal plants. The 1979 shortage of rail cars that did not carry through 1980 also did not carry through in 1981. Rail rates increased 12.8% over-all last year, while average freight rates for industrial minerals increased 15.5%, according to Neil Johnson, consultant. Also, the trucking industry posted a 5-6% decrease in rates due to deregulation. All in all, we in the industrial minerals section seem to be holding our own at least. Stanley J. Lefond Contributing Editor

Jan 5, 1982

By Donald Towse

The Permanente plant of Kaiser Cement & Gypsum Corporation is located at a unique thick deposit of Calera Limestone (Figure 1) on the southwest side of San Francisco Bay. Limestone is rare in the eugeosynclinal Franciscan assemblage, constituting less than 0.1 percent of the total volume. On the northwest part of the San Francisco peninsula Calera Limestone is present as isolated masses from the type sect ion near Rockaway Beach southeastward for ten miles, where the belt is truncated by the San Andreas fault. The large Permanente deposit is sixteen miles south of the truncated belt, on the northeast side of the San Andreas fault. Scattered small exposures are known for about twenty miles southeasterly from Permanente. (1,2) Most deposits of Calera are thin; the type section is about two hundred feet thick. At Permanente, however, the normal limestone section contains at least four hundred feet of limestone; and, due to folding and extensive faulting, the total vertical thickness of the limestone section is over 1400 feet. The unusual thickness of limestone is due to low angle thrust faulting. This fortuitous structure formed a deposit of limestone that supplies an 8,500,000 barrel cement plant in a major metropolitan market.

Jan 1, 1966

By D. A. Peterson

Laboratory testing was completed to determine the effectiveness of a fiberglass cable bolt (FCB) as a cuttable rock support for a continuous, hard-rock mining method. The FCB consists of four Polystal tendons combined in a node/antinode fashion, with polyvinyl chloride (PVC) spacers forming the anti-nodes. The largest ultimate pull-out load achieved by the FCB was 22 t (48,400 lb) at 89% of the tendons' theoretical pullout load. This premature tendon failure is accredited to: • differential stresses within the tendons and • differential tendon displacement. An increase in pull-out resistance for a given embedment length is due to: • increased bond area, • reduced interfacial shear and • "wedge" effect. The critical embedment length was found to be 40% less than for conventional steel cable bolts (SCB) at a 127-mm (5-in.) node spacing. An FCB can have up to a 92% increase in load-carrying capacity over a conventional SCB at equal embedment lengths. The load carrying capacity is equivalent to SCB at a 960-mm (37.8-in.) embedment length. Though the FCB is 7.5% more expensive than the conventional SCB (installed), this cost may be offset by increased performance. FCBs are a potentially viable support alternative for continuous hard-rock mining.

Jan 1, 1993