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By B. J. Arnold

During the past three years, coal samples covering a range of coal rank, ash content, size consist, grindability, and moisture content have been tested for their flow properties using a triaxial shear tester that measures the unconfined yield strength in a compressed sample of coal. The ratio of this unconfined yield strength to the sample bulk density is part of the equation used by handling system manufacturers to calculate the critical arching or critical ratholing diameter needed to ensure that coal will flow from bunkers or bins. This ratio also serves as an index to compare the flow tested. To test the applicability of the index to predicting problems with coal flow, a series of tests were conducted at CO Inc.'s Coal Quality Development Center (CQDC) in Homer City, Pennsylvania. Tests covering ranges in size consist, moisture content, and ash content were conducted by first filling a small two-ton bin with coal and then emptying the bin at a pre-set discharge rate. The actual discharge rate from the bin under the various conditions tested was measured. Samples of the coal discharging from the bin were collected. One sample was analyzed for ash, moisture, and size consist; another sample was sent to the Iowa state University for trivial shear tests (supplying an index measurement). Actual flowability results from the bin were then compared to the measured index to determine the applicability of the handleability index in actually predicting coal flow problems. This paper describes the correlation between handleability index and bin flow and explains the next stages of the project.

Jan 1, 1992

By LaTasha R. Swanson, Jennica L. Bellanca

Proximity detection systems (PDSs) for mobile machines have the potential to decrease injuries and fatalities. Early adopters of the technology have identified some challenges, which present an opportunity to explore and improve the integration of mobile PDSs in underground coal mines. The current research study applied the task-technology fit framework to investigate the fit between mobile PDS technology and mining relative to health and safety, from the perspective of leaders at two coal mines. Quantitative results from the study show that mine leaders evaluated mobile PDS favorably for training and ease of use, system feedback, user authorization and experience, and less favorably for safety, compatibility, task completion, and reliability. Qualitative results reveal specific task, mine, and system characteristics that may have influenced leaders’ evaluations. The study includes considerations and suggestions for safe technology integration

By M. J. Gula, S. S. Xue, E. P. Horwitz

A study has been conducted to remove iron from sulfate solutions using Eichrom's Dipexo® extractant, P,P'-di(2ethylhexyl) methanediphosponic acid (H2DEH[MDP]). It is found that this extractant can effectively and selectively extract ferric ion from highly acidic solutions. Ninety-nine percent of the iron was extracted from a simulated feed solution in a single stage. The separation factor, Fe/Zn, was 106. Over 90% of the iron in a loaded organic can be recovered in an aqueous solution by reductive stripping. This paper presents the experimental results. A new process for iron removal using Dipex extractant is described and discussed.

Jan 1, 1999

By D. M. Schubert

As a clean and renewable energy carrier, hydrogen is an important component of most alternative energy portfolios. Hydrogen combines very high energy content by weight with excellent environmental attributes. Since hydrogen reacts with oxygen to produce only water with release of energy, it can be used to power fuel cells, combustion engines, and turbines, without production of greenhouse gases at point of use. However, because of its low volumetric density, storing pure hydrogen is impractical. Thus implementation of hydrogen technologies requires materials that can safely store and release large amounts of hydrogen (1,2). In recent years, the U.S. Department of Energy (DOE) and other governmental agencies around the world sponsored extensive research on hydrogen storage materials, including those based on boron. These efforts have resulted in significant advances in hydrogen storage technologies. Boron materials stand out as leading candidates for hydrogen storage among the many options investigated. Combining excellent hydrogen densities, release rates, and safety characteristics, some boron materials can hold substantially more hydrogen by weight and volume than even pure liquid hydrogen (3-5).

Jan 1, 2010

By S. A. Diatchkov

There is a misconception that mineral-project economic evaluations in the former Soviet Union are either nonexistent or very limited. This is not the case. In fact, there are at least two basic methods that can be utilized to evaluate the vast mineral resources of the Commonwealth of Independent States (CIS). Evaluation procedures are based either on a comparison to known projects, which may rely on limited available data, or on potential-profit calculations, which generally uses more extensive databases. Significant philosophical differences between these systems and those utilized in the Western world include the following: •Under the centralized-government system, the economic evaluation of a mineral project was based on artificially determined mineral prices and costs. Every ten to 12 years, prices for concentrates and metals were established by the Council of Ministers and remained unchanged until the next reconsideration of prices .

Jan 1, 1995

By J. C. Norman

The United States was the world’s largest producer and consumer of boron compounds during 1995. According to estimates from the US Geological Survey(USGS), boron mineral concentrate and chemical production in the United States totaled an estimated 1.1 Mt(1.2 million st) yielding 602 kt (663,000 st) of B2O3 for an estimated value of $462 million. This level of production exceeded 1994 revised production figures by about 9%. The United States continued to provide nearly all its own boron supply while maintaining a strong position as a source of sodium borate products and boric acid to foreign markets. During 1995, about 900 people worked in domestic boron mines and plants, about the same as in1994. USGS estimated total world production of boron during 1995 to be about 3 Mt (3.3 million st), yielding about 1.6 Mt (1.8 million st) of B2O3. World production in 1995 was about equal to revised 1994 levels.

Jan 1, 1996

By Henry R. Linden

The demand for natural gas continues to increase at higher than anticipated rates, partly because of its widening price advantage over most other fossil fuels when the cost of air pollution control is included. However, there are clear indications that natural gas supply from the contiguous 48 states and continental shelves will not indefinitely keep up with this rapid growth in demand. Projections are presented which define the extent of potential deficiencies from the 1970's to the year 2000. Among the sources of supplemental gas - imported pipeline natural gas from Canada and Mexico, tanker import of liquefied natural gas, and synthetic pipeline gas from coal and oil shale - by far the most abundant at potentially competitive costs is pipeline gas from coal. The state of development and relative economics of the various coal gasification processes are reviewed. It is shown that synthetic pipeline gas could become a very substantial market for bituminous coal and lignite at current minemouth prices - 60-70 million' tons of coal for each trillion cubic feet of synthetic pipeline gas produced. This corresponds to only slightly more than the current annual increase is gas demand.

Jan 1, 1969

By John Rajala

The Otjikoto Gold Mine in the Republic of Namibia is located approximately 300 kilometers north of the capital city of Windhoek. The project features surface mining with a modern gravity/carbon-in-pulp mill for ore treatment and recovery of gold. Initial mill design capacity was 2.5 million tonne per annum but then expanded after 9 months of operation to 3.1 million tonne per annum. The technical steps to establish the Otjikoto mill design from process selection in the due diligence stage, through flowsheet development in the feasibility study followed by detailed engineering design are reviewed in this paper along with mill performance during start-up and in 2019.

Oct 30, 2020

By Paul B. Valenti

The Nevada Moly Operation of Anaconda Minerals Co., (a molybdenum/copper ore body) was initiated in 1978, with a contract to Bechtel Civil and Minerals Inc. for construction of a mining and milling facility near Tonopah, NV. Ground was broken on the concentrator portion of the project in August 1979$ with a multi-phased startup of the mill beginning in June 1981. Processing design tonnage of 20 000 t/d (22,000 STPD) was reached in early 1982. Major pitfalls of rapid design and implementation of engineering, construction, and startup are considered. The operation of the concentrator including SAG milling, ball milling, bulk rougher flotation, copper/moly separation, moly regrinding and cleaning, thickening, and product loadout are discussed.

Jan 1, 1983

Mining is big business in Ontario. The province is Canada?s leading mining region. It consistently ranks among the top 10 jurisdictions worldwide for exploration spending, reaching about C$1 billion in 2011. More than 26 percent of all exploration and appraisal dollars spent in Canada are invested in Ontario. Minerals produced include nickel, copper, platinum group elements (PGE), cobalt, zinc, diamonds, gold and silver. It was reported that there are more than 600 mining exploration projects in the province. And, recent discoveries of chromite in northern Ontario?s Ring of Fire will add to the province?s mineral production in the coming years.

Jan 1, 2013

By Rameshwar Sah, Basavaraja Maribasappanavar, Sangamesh Desai, G. Balachandran, Ravi Kant Sagar

The present research work deals with the effective utilization of hematite ore containing goethite, kaolinite and gibbsite losson- ignition (LOI) phases in pellet making without deteriorating product pellet properties by optimizing the induration cycle especially drying and preheating of pellets. Adequate drying and preheating of pellets before sintering is of prime importance to sustain the desired properties of pellets. Green pellets of + 8 to − 16 mm size were prepared in a laboratory disc pelletizer and indurated by varying drying and preheating temperatures in a laboratory Raising Hearth Furnace (RHF). Produced pellets were assessed for physical and metallurgical properties. Improvement in drying and preheating temperature simultaneously helped in mitigating fired pellets’ property deterioration. Drying at 300 °C and preheating at 750 °C helped in the maximum removal of matrix LOI from the pellets before firing and enabled the production of pellets of desired properties. Laboratory scale findings successfully implemented at existing 4.2 MTPA capacity pellet plant of JSW Steel Ltd. Vijayanagar and high LOI iron ores (IOs) utilised which resulted in reduction of average monthly pellet fines generation by ~2 wt. %.

Jun 4, 2022

By G. F. Revey

All underground operations have limiting factors that influence overall profitability. Hoisting, hauling, available headings, labor, milling capacity and other factors limit how much material can be removed from an underground mine. Consequently, when mines use limited labor to handle the additional rock from overbreak and to perform extra ground support tasks, productive activity is replaced by non-productive work. Mining economics are further penalized when overbreak causes dilution of ore grades. This paper reviews organizational systems that mines have used to create environments which foster the creation of successful overbreak control programs. Actual case histories document the various quality improvement techniques, worker incentives, and practical project management systems used by these mines. A brief review of controlled blasting technology sources and overbreak measurement tools is also included.

Jan 1, 1997

By Chen-Luh Lin, Jan D. Miller, Sindhoora Puvvada

Most of the future phosphate resources in Florida, which accounts for 70  percent of production in the United States, are contaminated with too much dolomite that is difficult to remove with existing industrial practices. The low-grade ore quality coupled with increased phosphate demand is of concern to the Florida phosphate industry. In order to resolve the dolomite issue, various beneficiation technologies were designed and evaluated, but none have been sufficiently successful [1]. 

By Franziska Wolf, Rainer Ellmies, Helmut Mischo

"Mining is an important part of the economy of Namibia. In 2016, 11.1 percent of the GDP was the result of mining activities with 22 active mines (The Chamber of Mines of Namibia, 2016). Only one of them consists of an underground mining operation.The global annual production of fluorspar is approximately 5.4 to 6.3 Mt (6 to 7 million st) (U.S. Geological Survey National Minerals Information Center, 2017). Okorusu has produced on average about 45 kt/a (50,000 stpy) in recent years (U.S. Geological Survey National Minerals Information Center, 2015).The Okorusu Mine is Namibia’s only fluorspar mine. Fluorspar was mined in an openpit mine with four individual pits (A-D) since 1980. In 2014, the mine closed due to the increased stripping ratio and beneficiation problems. The mine assets were bought by Gecko Namibia. Currently, Gecko uses parts of the processing plant for beneficiation of graphite from a neighboring mine. Figure 1 shows a panoramic view with the four pits and the mine village.The intent is to develop a concept for the further underground development of the mine. There are still about 6.3 Mt (7 million st) of measured resources left in the deposit, with an average grade of 27.5 percent CaF2. This study focuses on the underground mine design. The above-ground plant and facilities are considered as remaining unchanged.For solving the task to design the mine, a site visit for data collecting was conducted. Resource estimations were calculated based on existing drill data, and consequently, block models were created. The development of the mine design included the selection of the most suitable mining method, mining technology and mine organization. Moreover, some economic considerations are pointed out, followed by a profitability assessment."

Jan 2, 2018

By Rudrajit Mitra, Erik Hulthén, TOBIAS HARTMANN, ELISABETH CLAUSEN, Aarti Sörensen

There has been an ongoing debate on how to transform engineering education to better prepare students for today`s professional world that is characterized by increasingly complex problems and challenges that engineers are tasked with upon entering the industry. Within the conceive–design–implement–operate (CDIO) framework, entrepreneurship education presents a valuable pedagogical approach to foster the necessary skills of the students through integrated, hands-on, active learning experiences. While numerous publications have addressed possibilities of how experiential, problem-based, project-based and active learning can be integrated into engineering curriculum, there has been hardly any attention on mining engineering with respect to adopting this approach. This paper will address the possibilities of integrating entrepreneurship education into mining engineering programs in particular. This paper will enhance and foster discussion among academics from mining engineering on how to integrate elements of entrepreneurship education on a course, program and departmental level to infuse value creation experiences across the curriculum.

May 25, 2022

By Paul E. Rosten

This paper describes some of the latest improvements that have been incorporated or planned by the Cleveland-Cliffs Iron Company to reduce operating costs and improve pellet quality. The Cleveland-Cliffs Iron Company operates and manages mining, beneficiation, and pelletizing operations in Michigan, Canada, and Western Australia. This paper deals with the grate-kiln pelletizing operations at Republic, Humboldt, Tilden, Empire, and Pioneer in Michigan, and the Adams and Sherman in Ontario, Canada. Table I characterizes .each operation in regard to location, ore type, pellet capacity and date that pellets were first produced. All of the operations with the exception of Pioneer and Tilden, utilize downdraft-two-pass grate cycles of drying followed by preheating. Pioneer utilizes an all-downdraft, three-pass grate cycle which consists of three drying zones followed by the preheat zone. The Pioneer and Tilden cycles have been described previously. (1) (2)(3) Tilden utilizes a three-pass grate cycle with a stage of updraft drying, followed by two downdraft drying stages. Recuperation systems which supply hot gases to a drying zone from second stage cooling were designed and furnished for Tilden I. Tilden II will be identical. Empire IV will also be furnished with a recuperation system. The Adams grate-kiln system was retrofitted with a recuperation system. This paper will summarize some of the efforts that are in effect or planned for grate-kiln pelletizing systems to (1) reduce operating and maintenance costs, (2) reduce energy requirements, (3) improve product quality, and (4) meet environmental standards.

Jan 1, 1977

By J. de Bakker

It hardly needs to be repeated that if coal is to continue as America’s premier source of cheap energy, it is absolutely necessary that the carbon dioxide from its combustion somehow be sequestered. A promising method proposed to accomplish this is the “indirect” carbonation of serpentine in a concentrated magnesium chloride brine. Indirect carbonation could be also applied to precipitate magnesium in lateritic nickel processing: this would not only solve magnesium-control problems in laterite hydrometallurgy, but also reduce its energy requirements and create CO2-sequestration credits. Fifty-five percent of the electricity generated in the United States comes from coal-fired power plants, and American coal reserves can last over 500 years at 1990-level consumption1. Coal is therefore both abundant and cheap: it could (and in fact probably will) continue to be an affordable source of energy, both for producing electricity and as a feedstock for liquid hydrocarbon production by Fischer-Tropsch reactions. As a result, it is important to find a workable method of permanently sequestering CO2.

Jan 1, 2007

By J. G. Craig

This paper initially was to be on the design, construction and operation of the Lucky Friday mill. However, this subject has been pretty well covered in some of the mining publications in the past few years - specifically Mining Congress Journal for April, 1961 and Mining World for March, 1962- : In order to avoid too much repetition, we decided to present in this paper a comparison of the Lucky Friday mill constructed in 1959, and the Mayflower mill built by us in 1962. During the past three years Hecla Mining Company has constructed two relatively small mills: The Lucky Friday mill at Mullan, Idaho 750 T/day; and the Mayflower mill at Heber, Utah - 450 T/day. These mills were engineered, designed and constructed by Hecla, using principally our own personnel, with very little outside (contractor) labor employed. This paper presents a comparison of some of the interesting features of these mills, and where differences occur, it discusses the reasons for the various differences. It compares such points as the testing program, physical layout of the plant, construction costs, the grinding section, the flotation section, tailings disposal, metallurgy, recovery, grades, operating costs, etc. To help illustrate, and to compare these features, we will project pairs of slides showing each of the two mills. First a little background and history on the properties ---

Jan 1, 1964

By R. A. Wyman

"The froth flotation process was patented by E.L. Sulman, H.F.K. Pickard, and John Ballot in 1906 . . . . . . . . . .James M. Hyde installed the first froth flotation process in the U.S., about August 1, 1911, at the Basin Reduction Co. plant, Basin, Montana . . . . . . . . . .By 1914, 42 mining companies were operating or experimenting with the flotation process . . . . . . . . . .The period 1930 to 1960 saw the application of flotation spread to nonsulphide ores and become the key factor in the economic production of many industrial minerals". So states FROTH FLOTATION, 50th Anniversary Volume, published by AIME in 1962. It is interesting, to observe that the Mines Branch, now part of the Canadian Department of Energy, Mines and Resources, was established in 1907 through an act of Parliament entitled, "The Nines and Geology Act". In 1911, a mineral dressing group was formed and a laboratory was constructed. By 1921, an engineer was devoting full time to industrial mineral processing problems.

Jan 1, 1971

By C. L. Jiang, B. K. Parekh, X. Shao

Among the impurities present in phosphate ore, dolomite is the most difficult to remove. This is because dolomite and phosphate have similar chemical compositions and because the dissolved species of dolomite is adsorbed on the surface of the phosphate mineral. A new amphoteric surfactant was found to be a suitable collector for the separation of dolomite and phosphate. Flotation results showed that the new amphoteric collector had a high flotation selectivity for dolomite over a wide pH range. studies on the flotation of francolite and dolomite in each other's supernatant demonstrated that the dissolved ions had little effect on the selectivity of the new collector. It was found, however, that the dissolved ions were detrimental to the flotation separation using sodium oleate as collector. From a mixture offrancolite and dolomite containing 26.2% P2O5, a phosphate concentrate containing 35.2% P205 with a 90% recovery was obtained using 290 g/t of the amphoteric collector. The rejection of MgO was 81.41 %.

Jan 1, 1999