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By J. D. Patsey

A computer program has been developed for use by the mining engineer for analyzing drum-type hoists prior to the modification of an existing system or the designing of a new one. Its use permits the preliminary evaluation of a system before seeking the technical assistance of mine hoist designers and manufacturers. Compatible with an IBM-PC, the user-friendly program accepts a variety of data and can analyze hoisting systems for any balance state. The extensive program can be used to: (1) calculate skip capacity to yield a desired production rate; (2) solve for required drum face width; (3) select a permissible wire rope from a menu of 50 available rope types: (4) estimate total horsepower of the hoist plant; and (5) estimate power cost. An example of the model's use in evaluating a hoisting system will conclude the paper.

Jan 1, 1986

Exploration for SX-EW copper deposits and plant operation depend largely on the copper and gangue mineralogy inasmuch as? they govern the feasibility of leaching. Mineralogical parameters are pivotal in identifying if an ore is suitable to dump, heap, thin layer, vat or agitated leaching and/or if the ore requires curing, bioleaching or alternate lixiviants. Problems in metallurgical testing, production leaching and recovery forecasting are very often related to lack of mineralogical data. This presentation will illustrate the use of quantitative mineralogical analysis for exploration, acquisition assessment and optimization of copper leach operations.

Jan 1, 1996

By Margaret Fuller Boos

Precambrian granitic pegmatites on the west, south west, south and southeast slopes of Storm Mountain, Larimer County, northern Colorado, were explored and mapped geologically 1956-1959. The area between Crystal Mountain Mining District on the north and Hyatt pegmatite mine area on the south was nearly inaccessible until a company built an access road, which was completed in 1959, into Roosevelt National Forest and its jeep-type roads. The area is extremely rugged, rising from some 6,000 feet on the highway at Drake, on Big Thompson River, to an altitude of over 10,000 feet at the summit ridge of Storm Mountain. Almost innumerable pegmatites of every possible type of granitic pegmatite intrusion infest the Precambrian gneisses and schists of the southwest-tilted fault block of Storm Mountain. The major bodies stand at least 100 to 200, feet high above the surrounding forest floor. Core drilling has shown that some extend to at least 200 feet below the surface. They blunt out at the southwest, some keel out below and others are faulted out at their southwest ends. Strike length ranges from 200 to 600 feet. The massive bulky bodies have nearly vertical walls. Contents are zoned or ribboned and layered. They consist of local commercial bodies of beryl, potash feldspar, mica, uranium minerals and quartz. As yet no lithium minerals have been encountered.

Jan 1, 1960

By C. O. Petter

This paper, in its first part, compares the profile and economic weight in the extraction of industrial minerals and aggregates to the so called conventional mining activities (metals, coal, gas and oil extraction) in Brazil. In its second part, a descriptive analysis of the present situation of the education in Brazil is made, emphasizing the graduation and post-graduation formation especially in engineering. The curricular structure of the schools that prepare the mining workforce is discussed and the presence of specific subjects in industrial minerals is evaluated. Finally, considerations are made on the actions being taken in the main universities and companies, aiming to improve the formation of the specialized workforce. The Brazilian mining production, comparing 2010 to 2011 showed an expansion of more than 3% (IBGE, 2012). Not bad, but nothing to do with the 13% growth between 2010 and 2009 (influenced by a recovery effect from the 2008 commodities? nightmare). The commodities that had a rising behavior were titanium, gypsum, nickel, graphite, bauxite, phosphate, chrome and chrysotile. All of them were eclipsed by the impressive growth of iron ore production. Some decreases could be noticed, eg. in zinc, kaolin, magnesite and salt production (DNPM, 2012). In fact, the mining activities followed the positive growth of the country these last 5 years. The commercial balance (exports against imports) was not spectacular (positive in US$ 30 billion in 2010). It is important to notice that the mineral commodities balance was US$ 35 billion, representing 27.4% of the total exports and 15.6% of the total imports of Brazil (DNPM, 2012). In this positive environment, the workforce in Brazil showed progress in number of formal jobs and average revenues.

Feb 23, 2014

By F. Calizaya, M. G. Nelson

This paper presents a summary of basic requirements for the design, installation and operation of booster fans in coal mines, especially in deep and/or extensive mines. It includes a brief description of the major steps that should be followed to ensure that these units are used in coal mines safely and efficiently. The guidelines were prepared based on the standards and regulations adopted by two prominent coal mining countries, the best practices developed by the mining industry, and the applicable standards used in the United States for the fail-safe operation of main fans.

Jan 1, 2015

By Guillermo V. Borquez

The economics of open pit mine design are dictated by three basic elements: cut-off grade, stripping ratio and slope angle. Although these elements are functions of a number of independent parameters, they are interrelated through their influence on the overall economics. The optimum slope angle is the most uncertain element to determine, because rock mass properties are difficult to obtain. However, for preliminary estimation, the slope angle can be determined from the relationship between the probability of failure and the safety factor. The economics of the slope selected will depend on a profit versus risk judgment. In this paper, the author will present an actual case of application of this postulate.

Jan 1, 1977

By D. D. Gertenbach

"The successful commercialization of a pressure oxidation (POX) process for recovering metal values, including gold, copper, zinc, nickel and molybdenum, is the result of a carefully planned development program. The initial task involves developing one or more conceptual flowsheets, including the POX autoclave and downstream purification and recovery steps. A laboratory program is completed to determine the technical viability of the flowsheets, define the operating parameters for each step and provide information for an initial economic assessment of the process. The process is then confirmed during a continuous pilot plant program, providing engineering design data and other information for the commercial design. A well-thought-out development program has been shown to be critical for reducing the risk of commercializing POX processes. Experiences developing POX processes for refractory gold ores and copper concentrates are briefly discussed. IntroductionPressure oxidation (POX) has become a common commercial operation for processing sulfide-bearing feedstocks. These feedstocks include gold ores and concentrates; copper concentrates; nickel concentrates and mattes; zinc concentrates; and molybdenum concentrates. Drivers for the development and commercialization of POX processes include:• The high cost for pyrometallurgical processing of sulfide ores, much of which is attributed to environmental controls.• The motivation to implement safe and more environmentally attractive alternatives for sulfide ores.• The need to process increasingly difficult ores with complex mineralogy.• Improvements made over the last 25 years in POX equipment design and experience operating commercial POX plants.Although the capital and operating costs for commercial POX processing can be high, this technology is capable of rapid oxidation of most sulfides and arsenic minerals in the feed, with little noxious gases and environmentally stable iron arsenate and other iron compounds in the POX residue (Marsden and House, 2006).In POX operations, sulfides are oxidized to either sulfates or elemental sulfur in an autoclave at elevated temperature and pressure with oxygen gas. An example is the overall oxidation reactions of chalcopyrite when sufficient oxygen is present, shown in the following reactions:"

Jan 1, 2016

By Robert Kimutis, Heather Dougherty, Eric Watkins

Gas wells have often intersected mining resources, but unconventional shale well drilling has more recently challenged mines to balance the risk of interaction due to higher pressures and larger quantities of gas. Full extraction mining, such as the longwall method, induces ground movement that may influence the casings if wells are drilled within the mining area. The possibility of a casing shear would lead to the risk of unplanned gas migration into the mine. This has the potential to quickly overcome the ventilation system and reach the explosive range which, if ignited, can have catastrophic consequences on the health and safety of underground workers. The utilization of network software to model mine ventilation is a common practice in the mining industry as a predictive tool for planning and monitoring and can assist with a well breach scenario over a large mining area. This work focuses on a well breach in between two longwall panels after second panel mining with gas entering primarily through the gobs of the adjacent longwall panels. Applying the network software Ventsim, a gob zone and ventilation network were created to better understand the distribution of gas within the mine and the limitations and effectiveness of a ventilation system. The model shows both a transient flow simulation and steady state concentrations throughout the mine ventilation system. Using a standard Pittsburgh coal seam longwall ventilation scheme, we find that the system can dilute a significant inflow of up to 700 cfm of methane.

Oct 12, 2023

By Ana Chiquini, Clayton V. Deutsch

The most common approach used in the mining industry for mineral resources modeling is to estimate the grades using ordinary kriging and report the recoverable resources based on this deterministic estimated model. Mineral resources calculated with kriging are a smooth representation of the actual distribution of grades and do not provide an assessment of uncertainty. Unlike kriging, simulation reproduces the variability of the grades in the mineral deposit and provides an assessment of uncertainty. Reporting mineral resources directly on high-resolution simulation results would assume perfect knowledge of the grade at the time of mining and selectivity at the scale of the data. There will always be uncertainty left at the time of mining, so assuming perfect knowledge of the grade in the future is incorrect. There are two concerns when geostatistical simulation is used for resources modeling: the information and the mining selectivity effects. A new framework for resource estimation is proposed with two separate modules to address those concerns. The information effect is accounted for by anticipating the additional production data that will be available at the time mining to guide the destination for the mined material. The mining selectivity effect is addressed by mimicking the grade control procedure to get mineable dig limits at a chosen selectivity, represented by a minimum mineable unit size. In addition to a prediction of recoverable resources that will be closer to the material mined in the future, the framework proposed provides an assessment of local and global uncertainty for risk management.

May 26, 2020

By G. Mbuyi Kamba

Literature is rather abundant on the topic of steady-state network analysis programs. Many versions exist, some of them have real extended facilities such as full graphical manipulation, fire simulation in motion, etc. These programs are certainly of great help to any ventilation planning and often assist the ventilation engineer in his operational decision making. However, what ever the efficiency of the calculation algorithms might be, their weak point still is the overall validity of the model. This numerical model, apart from maybe the questionable application of some physical laws, depends directly on the quality of the data used to identify its most influencing parameters such as the passive (resistance) or active (fan) characteristic of each of the branches in the network. Considering the non-linear character of the problem and the great number of variables involved, finding the closest numerical model of a real mine ventilation network is without any doubt a very difficult problem. This problem, often referred to as the parameter adjustment problem, is in almost every practical case solved on an experimental and "feeling" basis. Only a few papers put forward a mathematical solution based on a least square approach as the best fit criterion. The aim of this paper is to examine the possibility to apply the well-known simplex method to this problem. The performance of this method and its capability to reach the global optimum which corresponds to the best fit is discussed and compared to that of other methods.

Jan 1, 1995

By Badiozamani Khosrow

Introduction The mining industry has been using computers since the late 1950s. Despite this early start, the use of mine planning software is not a common practice in many operations. But the trend might be changing because of the availability of relatively inexpensive personal computers (PC). The introduction of these machines has generated unprecedented interest by mine managers to computerize their planning operations. However, some managers have become disappointed with the PC's lack of adequate software and the inability to handle the massive amounts of information required for modeling. This paper is an attempt to shed some light on the future of computers in the mining industry. It will examine: • historical progress in the computer industry, • future advances in the computer industry, • historical usage of computers in mining, and • future alternatives available to mining. Historical Progress The computer industry has come a long way since the first full-fledged electronic digital computer Electronic Numerical Integrator And Calculator (ENIAC) was built in 1946. This machine weighed more than 27 t (30 st). It contained 19,000 vacuum tubes, occupied 139 m2 (1500 sq ft), and could perform 5000 additions per second. By contrast, today's fastest, commercially available computer is the CRAY-X. It weighs less than 5 t (6 st), has no vacuum tubes, occupies less than 9 m2 (100 sq ft), and performs over 100 million operations per second. This is an incredible advancement in less than 40 years. One person commented on the rate of advancement in the computer industry. He suggested that if the auto industry had advanced at the same rate as the electronics industry, we could buy a Rolls Royce for $2.75 and it would run

Jan 9, 1984

By Andrew Scogings

The current edition of The Australasian Joint Ore Reserves Committee (JORC) Code was published in 2012 and, after a transition period, the 2012 edition came into mandatory operation on Dec. 1, 2013. There is a significant change between JORC 2004 (Clause 44) and JORC 2012 (Clause 49) for the reporting of industrial mineral resources and reserves, which should be addressed by ASX-listed players in the industrial minerals space.

By J. M. Elegante

A belt drive attendant was working underground during his shift at the junction of two belt drives. He worked alone, but communicated with others at the mine by underground phone. At noon his shift foreman stopped by his workstation. At 2:00 p.m. he was contacted by phone by a fellow belt drive attendant. At 5:00 p.m., he was found dead by the oncoming evening shifter.

Jan 1, 1989

By R. A. Young

Effective October 1, 1958, President Eisenhower imposed, by Presidential Order, fixed import quotas on lead metal and lead concentrates and also on zinc metal and zinc concentrates. He did this in response to an escape clause case under the Trade Agreements Act filed by many of the large and small lead and zinc mining companies in September 1957. It is the purpose of this paper to give the experience of the lead-zinc industry under this order during its first two years and some observations on what might have come about under different conditions of U.S.A. consumption. Before considering these various experiences and observations, it seems wise to first outline briefly the basic problem which prompted such an order. Under the Tariff Act of 1930, the duty on pig lead was fixed at 2-l/8¢ per pound and slab zinc at 1-3/4e; per pound. The ores, concentrates and closely related products of these metals carried closely related duty rates. The Trade Agreements Act of 1934 and succeeding similar acts had given the, President the power to lower these and other duties. As a result-of various negotiations with foreign nations, by 1951 these duties had been lowered to their present day rates of 1-1/16 per pound on' pig lead and 7/10o, per pound on slab zinc. Related ores, concentrates and semi-fabricated forms of the metals received commensurate treatment. Under these acts, the Tariff Commission has the right to recommend to the President duty increases, specific quotas or both if find that imports have injured the affected industry. He has the right to accept or reject such recommendations, in whole or in part, in the light of the national interest,

Jan 1, 1961

By W. E. Threlkeld, J. A. Treacy, L. J. Stewart, J. C. Ruckmick

The Mustang Draw sulfur deposit is developed in a dolomite reef complex in the Permian San Andres Formation on the eastern margin of the Midland basin in Glasscock County, Texas. Interpretation of the genesis is dependent upon coincidence of a NE-trending fault system with the NW- trending reef complex. The reefs, reef talus, and oolites contained up to 30% interstitial anhydrite. It is indicated that artesian ground waters, hydrocarbons, and bacteria circulated into the reef complex along the fault zone. Bacterial consumption of hydrocarbons and anhydrite created extensive porosity, permeability, and deposition of sulfur in vugs and cavities, and along fractures in the dolomite.

Jan 1, 1992

By R. L. Grayson, S. B. Bealko, L. L. Chasko, D. W. Alexander

In response to recent mining disasters and new mine rescue team legislation, NIOSH researchers conducted meetings across the United States with mine emergency response experts to investigate current needs and issues. Some of the issues include emergency response preparedness, mine rescue contests, real-life training capabilities and training facilities. Many new teams are being formed that must be trained for mine rescue team competitions as well as be ready to respond to a variety of mine emergencies, including a fire or explosion, a massive roof collapse, mine inundations or vertical shaft rescue situations. Therefore, it is important that these teams are adequately prepared and trained. This paper presents a summary of domestic and international coal mine rescue training facilities and identifies those that provide unique, real-life and/or state-of-the-art training. Research findings from this report will be used in further NIOSH investigations to improve coal mine rescue training.

Jan 1, 2010

By Adam Bedell, Jack Raymer, Brad Crenshaw

Tunnel contracts often include provisions for pre-excavation probing and grouting for areas ahead of the tunnel heading. If grouting triggers are met, tunneling stops, and grouting is performed. There is substantial variation within the underground industry on what criteria are applied to the grout verification hole that is drilled post-grouting and before excavation resumes. The criteria for determination of the effectiveness should be dependent on the geology and local hydrogeologic conditions. The purpose of this paper is to present specific criteria that can be used by a practitioner to determine whether tunneling can resume or if additional grouting is required.

Dec 1, 2022

By R. Quintero

The HYL Direct Reduction Process was the first in the world to operate successfully at industrial scale. The results were so innovative and attractive that other steelmaking companies acquired licenses for the HYL Process. Now in its 40th year of commercial operation, the HYL process has evolved into a modem, highly efficient and economical technology -HYL III. The technology offers high productivity, minimum energy and water consumption, electricity co-generation, raw material flexibility, premium quality DRI/HBI, and is highly versatile for meeting the specific needs of each user. A historical review as well as recent developments and future plans are presented in this paper.

Jan 1, 1998

Amid some of the worst economic conditions that the mining industry has been faced with in more than a decade, the mood among the large crowd at the 114th Annual Northwest Mining Association?s annual meeting was surprisingly upbeat. More than 2,200 attendees showed up at John Asuaga?s Golden Nugget Casino in Reno, NV for the conference held Dec. 1-5. And more than 200 companies exhibited in 240 spaces, including SME and the Minerals Information Institute. The number of attendees and exhibitors were the most for the conference in more than 10 years. The conference was held in Reno/Sparks for just the second time in its illustrious history but began under the cloud of global financial turmoil. Prior to, and during the conference, the industry news headlines were grim, to say the least. An alarming number of mine plans and expansions had been put on hold; hundreds of miners across the United States had been or were in the process of being laid off; commodity prices were falling and some of the biggest mergers in the industry fell through while miners around the world put the brakes on to take a wait-and-see approach. It was a painful time for many, but the downsizing actions taken by many mining companies was exactly what needed to happen, according to Industry Outlook Luncheon featured speaker Frederick Sturm. He is the executive vice president and chief investment strategist and member of Mackenzie?s Investment team. He has earned a reputation as one of Canada?s leading investors in natural-based companies and he also manages the Ivy Global Natural Resource Fund in the United States Sturm said that the mining industry has fallen hard and that he expects it to bounce back quickly, before falling hard again. In these tough times, he said, the companies that have pulled back on production early are doing the right thing in the long run.

Jan 1, 2009

By W. M. Tuddenham

It would be most difficult to place a date on the beginning of the revolution in analytical techniques that we have witnessed in recent years; but there is no question that the period since the end of World War II has seen a major change in thinking with respect to control and accounting analyses. For reasons relating to competition, much of this change was brought about in the chemical industries and only more recently has begun to affect directly the mineral industries. In considering the subject outlined in the title of this paper, one might well be tempted to discuss solely the more exotic methods of control and automation which have come into being in the past short while. In this paper, however, an attempt will be made to take a broader view and consider not only the application of newer purely physical methods of control but also those phases of chemical plus physical analyses that have bearing on our industry.

Jan 1, 1962