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By M. R. Paterson

Operational and economic factors tend to favor the application of continuous processes in preference to batch processes in the majority of mineral processing applications. In this paper, the requirement for a Continuous Elution Process is established and the development of a large-scale pilot plant is described. It is based on a Continuous Elution apparatus which has a number of special features. These are the subject of various patent applications. The apparatus is suitable for adaptation to the AARL, Zadra and other methods of elution. The performance of the Atmospheric Continuous Elution System (ACE) is concluded to have significant advantages over the batch process.

Jan 1, 1986

By Edward R. Mueller

As an alternative to a million dollar, sensor based, computer dispatching system, Cyprus Pima Mining Company has installed a home¬made analog computer. The device is used in conjunction with a standard radio-dispatching system; it is inexpensive and very simple to build and operate. It enables the dispatcher to make near opti¬mum dispatching decisions and to identify all off schedule haulage trucks. Since installation, Cyprus Pima has experienced significant increases in pit productivity.

Jan 1, 1977

By R. J. Sawyer

The Greens Creek underground polymetallic mine restarted production in 1996 from a newly discovered high grade ore zone. Efforts to improve payable gold recovery have focused on gravity separation. The paper compares testwork and plant results for a newly installed gravity circuit.

Jan 1, 1997

By Georgene Renner

With more than 800 booth spaces sold and 540 exhibiting companies displaying their wares, there was something for everyone on the exhibit floor of the 2014 SME Annual Meeting in Salt Lake City, UT Feb. 23-26. The following is a sample of what was offered at the 2014 meeting.

By Leandro Augusto Viana Teixeira, Angela Avelar, Ruberlan Gomes Silva, Virginia S. T. Ciminelli, Daniel Majuste

Rare earth elements are essential for modern life products and green technologies. Recent supply constraints have boosted the development of rare earth projects after the price peak of 2011. The feasibility of a project depends on the definition of a processing route, which in turn depends primarily on the rare earth mineral, with monazite and bastnaesite representing the two most relevant minerals. Monazite-type ores usually contain high acid consumption impurities, such as iron, aluminum, calcium, magnesium, and phosphates, and may also contain prohibitive levels of radioactive thorium in its composition. This work presents a thermodynamic analysis of a monazite system and discusses the fundamentals of a selective process route for rare earth extraction from monazite ores with high iron content. This process involves sulfation by means of concentrated sulfuric acid and roasting at a high temperature. The route yields high rare earth extraction with low iron and thorium extractions and low acid consumption. Rare earth extractions as high as 80% were achieved, while iron and thorium extractions were lower than 1%, and acid consumption was lower than 0.34 kg of sulfuric acid per kg of ore. The operational window was compared to the one predicted by thermodynamic modeling, with 700 °C representing the optimal roasting temperature

By L. R. Berry

The successful selection of a slurry pump depends on the accuracy and completeness of the information provided for the application. Inaccurate or incomplete information can result in incorrect pump selection and / or operational problems. Some information is more critical to the selection process than other information. A full description of the slurry (liquid -solid mixture) including the particle size distribution and maximum concentration, the flow, head and NPSH requirements are most important for successful slurry pump selection and operation. Common problems resulting from improper slurry pump selection will be discussed to illustrate the need for correct selection requirements.

Jan 1, 1996

By M. D. Johnson

Mina Santa Rosa, in west central Panama, is the first large-scale gold mine in Panama and will soon be the largest single-mine gold producer in central America (Fig. 1). At full production, the mine will process 1.8 Mt/a (2 million stpy) of ore and produce more than 1.8 t/a (60,000 oz/year) of gold and 9.3 t/a(300,000 oz/year) of silver. Mina Santa Rosa is a subsidiary of Greenstone Resources of Toronto, Ontario. Freeport-McMoRan geologists first visited the area in 1985. Their rock chip sampling adjacent to old shafts and adits confirmed widespread gold and trace element geochemistry anomalies. Surface mineralization appeared to be localized in and adjacent to narrow veinlets. However, they recognized astructural setting similar to the Nevada Tertiary volcanic-hosted epithermal gold systems.

Jan 1, 1996

By Fouad Faraj

For every blast pattern, zones of unique material types need to be classified before mining. Most material types can be summarized into different kinds of ore and waste. Blocks generated from blasthole assays are too small to be selectively mined so areas with a single material classification meeting the mine’s selective mining unit must be defined. Current industry standard practices are to manually draw ore/waste dig limits but this process is subjective and results in quantities of dilution and ore loss which can be improved upon to enhance the profitability of mining operations. Two weeks production data from a homogeneous Cu porphyry and heterogeneous Manto-type Cu deposit are used to assess the variability in the hand-drawn dig limits for 20 geologists, mining engineers, or ore control specialists and are compared with the optimal ore/waste delineation. The profit for 20 distinct hand-drawn dig limits for the homogeneous mine ranged by 3.7% from $10.5 million to $10.9 million averaging at $10.8 million. The percent range nearly doubled for the more heterogeneous mine at 5.9% from $17.9 million to $19.0 million averaging at $18.6 million. Using the optimal ore waste delineation, the profit increased to $11.0 million (1.9% increase) and $19.3 million (7.0% increase) for the homogeneous and heterogeneous deposits respectively. The natural variability, diggability requirement, and selectivity are identified as the main drivers of ore loss and dilution. Recommendations are provided for reducing the subjectivity in manual hand-drawn dig limits by integrating dig limit optimization algorithms as a tool to assist practitioners.

Feb 23, 2024

"A long-term mine production schedule optimization based on stochastic integer programming is presented that manages the risk due to geological variability and uncertainty while jointly considering mine profitability, truck fleet requirements and waste management. The evolution of the pit is controlled so that space within the mined-out pit is continuously provided to allow for tailings and waste rock to be replaced, thus minimizing the project’s environmental footprint. The method is applied at a taconite iron ore deposit and has a project net present value that is 16.9 percent higher than that of a conventional schedule and has a higher chance of meeting production forecasts. The stochastic schedule reduces equipment requirements by delaying waste mining and by mining selectively in order to meet plant ore feed requirements without stockpiling material, resulting in 23.7 and 26.2 percent lower mining capital and operating costs, respectively. IntroductionThe LabMag iron ore deposit is part of the Millennium Iron Range, a 210-km (130-mile) belt of taconite in northern Quebec and Labrador, Canada. LabMag has significant economic potential. It contains more than 3.3 Gt (3.6 billion st) of proven reserves at an average total iron content of 29.8 percent and is very low in impurities. However, on a project basis of 23 Mt/a (25 million stpy) of product, the required capital expenditure is estimated at more than $5 billion (SNC-Lavalin, 2014), which necessitates careful evaluation of all sources of risk. Resource estimation is one of the main sources of risk in a mining project as knowledge of the orebody is primarily based on drilling, which is often sparse because it is expensive. If the expected ore tonnages and qualities are not obtained when mining, the project cash flows are directly affected. The expected quantities and qualities of ore and waste are defined by the mine production schedule, which specifies the sequence of extraction and is dependent on the resource estimation. The goal of mine production scheduling is thus to maximize the expected profit, while also meeting all production targets and constraints, by creating an extraction schedule that is robust in the face of geological risk and has the highest chance possible of actually being realized."

Jan 10, 2017

By J. K. Pandey, ebashish Mishra, D. P. Mishra, N. K. Mohalik, S. K. Ray

The increasing demand for coal and depletion of shallow depth reserves are pushing towards deeper mining. In deeper coal mines with multiseam workings, the problem of ventilation surges many folds primarily related to air quantity requirement, heat, humidity and spontaneous heating/fire in goaved (gobbed) out areas. The paper describes the design of a new approach to improve the ventilation system of a real-life deep underground coal mine with multiseam workings. For this, the ventilation problem of one deep underground coal mine 6&7 pits Bhutgoria Amalgamated Colliery of Tata Steel Ltd. with multiseam workings has been studied in detail to determine an appropriate solution. A ventilation survey of the mine and computer simulation of the ventilation network has been carried out to reach a practical solution. Ventilation survey results have been analysed to develop a representative ventilation network of the mine for both qualitative and quantitative analysis. Further, computer simulation of the ventilation network of the mine has been performed to virtually verify the application of a highcapacity booster fan in the present ventilation circuit without disturbing the vulnerable areas. Field validation is also carried out after the implementation of the solution in the mine to determine its efficacy. Thus, the findings of this paper can be directly applied for the installation of booster fans to achieve the required air quantity in deep underground coal mines with multiseam workings having spontaneous combustion liabilities of upper seam goaved out areas.

Jun 2, 2022

By Robert D. Hansen, Basil S. Fee, Richard R. Klimpel

Despite the importance of froth flotation to the mineral industries as a means of separating various minerals, the commercial flotation reagents used have varied little in the last twenty years. Numerous articles and books are available describing existing flotation chemistry and its application, e.g., Fuerstenau (1962), Fuerstenau (1976), Aplan (1980), Somasundaran (1980), King (1982), Leja (1982), Ackerman, et. al. (1984), Crozier (1984), Hansen and Klimpel (1985). There are many reasons for this lack of significant new reagent development including the general utility and relative cheapness of collectors, such as xanthates, and frothers, such as methyl isobutyl carbinol and the glycol ethers. Another important reason is the inherent complexity of the flotation process itself coupled with highly variable and difficult to standardize feed materials which make reliable reagent comparisons difficult and seriously limit the use of theoretically based studies to "predict" new or optimal reagents. In addition, the higher cost of "specialty flotation reagents demands that their performance attributes be significantly greater than existing general all- purpose commercial reagents – something often difficult to prove in practice. Faced with this situation, a detailed applications research pro- gram [Klimpel (1980 ab, 1982, 1984 ab), Klimpel, et. al. (1982)] was organized from 1979-1985 on mineral flotation with the following goals: 1) the development of appropriate batch laboratory flotation testing techniques sensitive enough and statistically reliable enough to identify small differences in performance between different flotation tests (i.e., between various reagents, even those with relatively minor chemical structural changes); 2) the identification of mathematical models with appropriate numbers and types of parameters that have maximum statistical power to statistically distinguish between various time-recovery profiles; 3) the generation of laboratory and corresponding plant scale data in sufficient quantity and consistency so that the highly interactive nature of the "flotation system9' of chemistry/ equipment/operating conditions could be quantified; and 4) the invention and development of really new and unique reagents for giving improved flotation performance. The goal #1 was achieved [Klimpel (1980b. 1984b), Meyer and Klimpel (1984)l by basically using a simple automated paddle device for consistent

Jan 1, 1986

By Todd Wanless

This paper addresses the challenges experienced by the designer and three government agencies during implementation of major improvements for the Turkey Creek Tunnel in Kansas City, Kansas. The tunnel serves as a vital stormwater conveyance system for upstream flood control. Major structural deficiencies were identified within the tunnel including complete loss of sidewall and invert. Without immediate attention, complete loss of the tunnel arch could lead to blockage and extensive remedial repairs under difficult conditions. Considering that tunnel flows must be maintained during construction, a phased design and construction process has been implemented to expedite stabilization of the erosion cavities followed by tunnel liner repairs.

Jan 1, 2008

By Joseph D. Drew

Oregon Resources Corp. (ORC) has developed and permitted a new mining operation that incorporates a process design that will allow the unique paleo-beach placer deposits of southwestern Oregon to be extracted efficiently and economically, creating the only domestically mined source of a unique foundry grade chromite and specialty de-veining sand for precision casting. The operation will also provide an additional domestic source of garnet and zircon. Engineering design has been guided by the variable geology and mineralogy of the paleo-beach placer deposits as well as the need for a dry tailing scheme that resolves a lack of water resources at the placer locations and at the same time eliminates the need for slurry settling ponds, typical of paleo-beach placer operations in North America.

Jan 1, 2010

By D. A. Longhurst

Improper size distribution of the grinding media in a multicompartment mill can be a source of many operation problems encountered. Inefficient use of the power expended for grinding, and an undesirable product size distribution are two frequent resultants. It is necessary to resize the grinding media in the leading mill compartment at time intervals related to the abrasive nature of the material being processed. In practice, this is done when time permits and with sketchy guidelines, if any. Maintenance of the grinding media size distribution can be scheduled, and would be, with a realistic method supplied to the user.

Jan 1, 1984

By Joseph J. Yancik

An exchange of coal mine specialists was made with the USSR under an "Agreement on Exchanges and Cooperation in Scientific, Technical, Cultural, and other Fields for 1972-73," which was signed by President Nixon and Chairman Breshnev on April 11, 1972.* This exchange, in the field of coal mine safety and scientific research in hazard control technologies, was one of 16 technical exchanges covered under the above agreement. A six-man USA delegation visited the Soviet Union from September 9 to September 21, 1973. The delegation visited four deep mines, three in the Donets Basin and one in the Moscow Basin, a State Safety Research Institute, a Mine Research Station and associated Research and Design Institute, two Research and Design mining equipment institutes, and a Trade Union-sponsored health sanitarium. In Moscow, the delegation received a briefing on the Soviet coal industry from First Deputy Minister Vladimir Fedanov. A similar briefing was given to us on the Donets coal basin by the Deputy Minister S. Saratikyanz of the Ukrainian Coal Ministry. Lengthy technical discussions were held with the mines staff and research personnel at the institutes we visited. In addition, we had detailed discussions with key staff members of two combinats "Donetskugol" and "Tulaugol." In all these meetings, principal topics were matters of safety related to hazards associated with face mechanization, coal transport, methane gas control measures, gas outbursts, coal and rock outbursts, fire fighting add control, explosion suppression and control measures and other related hazard factors. There was also much discussion on miner training, miner's attitudes toward safety and accident prevention practices, and preparation and enforcement of safety rules and regulations. The delegation was very warmly received and constant attention was given to our needs. Our numerous questions were answered with candor although quite often in not as much detail as we would have liked.

Jan 1, 1974

By E. C. Speers

The Ray Mines Division has a long and illustrious history beginning in 1911, as one of the early underground block caving copper mining operations. The tonnage mined from the beginning of operations, increased from about 8, 000 TPD in the early years to the present daily tonnage of 22, 500 tons, mined by open pit methods. The Ray basic milling practice has been relatively unchanged since 1927 when the sulphide-flotation process was introduced at Ray. The leach-precipitation-flotation process introduced in 1956 has been the only major process change. The change from underground to open pit' mining was accompanied by a renewed drilling and exploration program which developed large tonnages of low grade copper ores both in the porphyry and the diabase. The ore bodies as outlined were of such a grade and size that it soon became apparent that economical operations could not be developed with the lower tonnage rate. Also that in order to develop these newly proven ores, it would be necessary to move the Ray crushing plant, the Ray. supporting shops, offices, a substantial part of the Ray townsite, and would also involve the rerouting of Mineral Creek, a typical Arizona stream which is dry most of the year but can flow as high, as 8, 000 second feet in the rainy season. This paper describes those changes in flow sheet made necessary both by the increased tonnage .and the requirement to move as much of the crushing facilities from the Ray area as practical in order to free the mine for the extension of its physical limits.

Jan 1, 1961

By Robert H. Hooff

The Vor-Siv Dewatering and Classifying Unit was developed by the Polish Coal Industry because of a need for a unit that would dewater and classify high volumes of solids in water slurry. To be practical, the unit needed to be relatively small in size, simple in design, involve low operating costs, and be able to give a dewatered product of less than 30% moisture. The answer to the above mentioned criteria was the Vortex Dewatering Sieve or, as we refer to it, the Vor-Siv. The original installation of the unit, as we know it today, began in 1963 when the Pols installed the unit in a full scale pilot application. By 1966, at least 30 of these units were installed throughout the Polish Coal Industry. This equipment was originally introduced in the United States in 1966 at the Fifth International Coal Preparation Meeting in Pittsburgh, Pennsylvania. The first installation in the United States was not achieved until 1970, when Mr. Fred Sachs of The Valley Camp Coal Company, Triadelphia, West Virginia, installed a Vor-Siv in a retrofit application. To date, there are 36 Vor-Sivs installed in this country and 29 in the process of being installed or delivered.

Jan 1, 1976

By Cory Bolen, Nadav Bar-Yaakov, Eric Zimmerman, Gregory Raines

The Chimney Hollow Reservoir Project broke ground in August 2021, constructing the tallest Asphalt Core Dam in North America, intending to improve reliability of drinking water supply to Northern Colorado communities. Aiming to expedite and streamline the geological mapping process in the tunnel, Stantec’s teams have developed a mobile and web-based GIS application for digital mapping input and rock mass evaluation, allowing real time decision making for assigning tunnel support class and resulting in a faster more efficient process. The following article presents and demonstrates the GIS mobile and web application-based process, the mapping results and review additional uses of the database created.

Jun 13, 2023

By Matthew S. Sanchez, Richard J. Lee, Matthew D. Zock, Drew R. Van Orden, Yumi Kamiya, Edward B. Ilgren

In many developing countries, asbestos is still used for friction products, insulation, and asbestoscement products. However, there is very limited modern data evaluating the airborne concentrations of asbestos fibers in operating asbestos plants. We have conducted an Industrial Hygiene survey, using state of the art PCM and TEM analysis, of a Bolivian asbestos cement plant that uses crocidolite during the production of roofing shingles and water tanks. The study is the first to use modern analytical measurements in an uncontrolled asbestos environment. Thus, this study offers insight into the historical airborne exposures at asbestos plants operating before modern dust control measures were introduced or airborne fiber levels regulated. The results suggest that fiber concentrations are far in excess of those for which current models would predict the onset of asbestos disease and mesothelioma. Significantly, the plant and community do not have an elevated incidence of asbestos disease or mesothelioma. Airborne fiber levels during comminution and fiber sizing ranged from 100 to as much as 1,000 f/cc. Fiber levels in the mixing, forming and finishing areas ranged from 0.5 to 9 f/cc. Based on the number of overloaded samples and estimates of their concentration, historical estimates of exposure may be underestimated by an order of magnitude. Also, an excellent correlation (1:1) between the PCM and TEM fiber concentrations (for fibers _0.25 um diameter) were obtained, raising questions about the conventional wisdom that the PCM systematically undercounts fibers. The results of this study further indicate that current models may overestimate the risk of asbestos disease and mesothelioma.

Jan 1, 2012

By J. T. Crawford

A comprehensive strategic planning model has been developed for the phosphate strip mining and chemical operations at White Springs, Florida. The computerized model covers ore body modeling, production simulation and financial analysis. Several innovative features in the model include using NPV techniques in ore body block economics, adapting the floating cone method to a floating template for generating dragline mining units automatically, using interactive graphics for designing mining units, and a dragline move economics algorithm for automatic scheduling of mining unit assignments and moves. Simulation of chemical plant production uses linear programming and concentrate inventory levels control mine operating schedules.

Jan 1, 1997