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By T. Harrison

Surface coal mines in West Virginia are receiving stringent NPDES discharge limits for total recoverable selenium. With limits in the low parts-per-billion range, selection and implementation of proper sample collection and analytical methods are imperative for quality assurance and control and for consistency in results. Given the typical oxidized form of selenium in the water, the low limits and the large and variable flow rates from the watersheds, end-of-pipe treatment is difficult and cost-prohibitive to implement. Discharge locations in the remote and steep terrain exacerbate the problem. To evaluate options for end-of-pipe treatment at a Patriot Coal Corporation surface mining operation in West Virginia, CH2M HILL performed wastewater characterization for a range of key constituents and selenium species at three outfalls for selection and preliminary sizing of appropriate treatment processes. A preliminary evaluation of base and wet-weather flows was done to understand flow variability considerations for discharges. A conceptual evaluation of technologies to treat selenium to permitted levels was conducted in con-junction with order-of-magnitude life-cycle cost estimates.

Jan 1, 2010

By Liming Yuan, Wei Tang, RICHARD THOMAS, JOHN SOLES, DAVOOD BAHRAMI

The abstract discusses the issue of mine equipment fires caused by hot surface ignition of flammable liquids. The research investigates the ignition probability of liquid fuels (diesel, engine oil, hydraulic fluid) on different metal surfaces (stainless steel, cast iron, carbon steel) under various ventilation speeds. The results show that the type of metal and ventilation speed influence the ignition temperature, with diesel being the most easily ignited fuel and carbon steel requiring a higher ignition temperature. The study provides data for understanding equipment mine fires and developing mitigation strategies.

May 4, 2022

By J. W. Furlan

Due to the time consuming nature of froth testing in a laboratory environment, it is required, due to practical limitations, to develop a method of applying a single set of performance test data (Visintainer & Whitlock, 2012) obtained for a single froth pump at a given speed, to a range of froth pump speeds and sizes, % air contents, and liquid viscosities. Head, efficiency, and flow all vary as functions of both liquid viscosity and air content. As such, it is necessary to develop a technique which can be used to interpolate from existing test data in order to predict froth pump performance for pumps of various sizes running at variable speeds. Details of the technique developed in order to achieve this goal as well as the insights gained from analysis of the resulting regressions are discussed. Additionally, comparisons are made between the performance predictions of this test-derived method and those of the Hydraulic Institute Standard for the effects of liquid viscosity on centrifugal pump performance (ANSI/HI 9.6.7-2010).

Feb 27, 2013

By Christine M. Kammer

In 1852, six barrels of iron ore were loaded aboard the steamer Baltimore at Marquette, MI, after a trip by mule wagon from the nearby Cleveland Iron Mining Co. Shipped to Sault Ste. Marie, they were portaged around rapids and reloaded onto another ship for the final journey to the steel mills of Cleveland. In 1855, the same company-the predecessor of Cleveland-Cliffs Iron Co.-chartered the brigantine Columbia to carry the first iron-ore cargo through the newly opened Soo locks. In 1981, about 2,190 iron-ore shipments in the form of taconite pellets were transported by water from US Great Lakes-ports. The total volume during the 284-day shipping season was 63 Mt (62 million It). Counting Canadian ship¬ments, almost 76 Mt (75 million It) of iron ore were moved on the lakes last year. The five Great Lakes-Superior, Huron, Michigan, Erie, and Ontario-contain 20% of the world's fresh water. The area surrounding the lakes has 26% of the nation's populations, 47% of its steel production, and over 80% of the raw materials required to make steel. That figure includes 71% of the country's iron ore and 40% of its limestone. Only the availability of low-cost water transportation of raw materials has kept the heartland steel producers competitive. Iron ore shipped on the lakes originates in the Lake Superior district's Mesabi and Marquette iron ranges. Major mines and their principal partners are Cleveland-Cliffs Iron Co.'s Empire, Republic, and Tilden; Armco and Republic's Reserve Mining Co.; Oglebay Norton Co.'s Eveleth; Hanna Mining Co.'s National and Butler; Inland Steel Co.'s Minorca; Pickands Mather & Co.'s Erie and Hibbing, the latter operated in conjunction with Bethlehem Steel Corp.; and US Steel Corp.'s Minntac. Pelletized ore products at these facilities is shipped through seven principal ports on the upper lakes: Duluth, Two Harbors, Silver Bay, and Taconite Harbor, MN; Superior, WI, and Marquette, MI, on Lake Superior; and Escanaba, MI, on Lake Michigan. In 1981, tonnage volumes ranged from 13.3 Mt (13.1 million It) shipped from Duluth, to Marquette's total of 5.4 Mt (5.3 million It). The ore docks, with two exceptions, are operated by railroads, most of which are owned by mining companies. Table 1 illustrates US iron-ore shipments in 1981. In the lower lakes, ore is discharged at dock facilities close to the great steel-producing centers of Chicago, Detroit, Cleveland, Pittsburgh, and Buffalo. Between the mines and mills, lakes and connecting waterways form one of the country's most effective transportation systems. Each year, vessels on the Great Lakes transport about 181 Mt (200 million st) of bulk industrial and agricultural materials-a greater quantity at a lower cost than can be achieved by any other transportation mode. Major commodities in Great Lakes trade are iron ore, coal, grain, limestone, cement, sand, and petroleum products. About 125 US flag vessels serve this trade, among them 13 "1,000-

Jan 10, 1982

By S. Deming

Coal is China's main source of energy. In 1988, 76.1% of commercial energy consumption was supplied by coal. To provide a rational utilization of its coal resources, China has paid considerable attention to coal preparation over the last 10 years. In 1980, there were only 105 washeries treating about 100 million tonnes of coal, but by 1988 there were 151 washeries treating 171 million tonnes per year. This paper describes the development of China's coal preparation industry; its growth, the equipment, and the technology. Statistics and information on the current status of the industry are also be presented.

Jan 1, 1991

By J. Kretschmann, R. Amiri

"The Sangan iron ore mines (SIOM) in Iran are located in a remote area near the Afghanistan border. The SIOM deposit contains a geological resource of 1.1 Gt (1.2 billion st) of mostly magnetite with an iron (Fe) grade ranging from 27 to 61 percent. The Iranian government plans a stepwise development of SIOM in cooperation with private companies to satisfy the growing demand of the Iranian steel industry. Sustainable development is an influential ethical concept in mining all around the world. However, a successful realization of a sustainable development plan is not possible without a foundation on the core values and regarding the specific circumstances of the individual mining country. This paper introduces SIOM and describes sustainable development activities undertaken during its development. From the early stages, these activities have been realized to secure the acceptance of the stakeholders in the region. To evaluate their effects, indicators were filtered to the ones with the highest priority for the stakeholders. Moreover, Islamic values and Iranian regulations and their influences on SIOM were analyzed.Mining industry in Iran The Islamic Republic of Iran holds 68 types of minerals, including salt, sand and gravel, gypsum, chrome, lead, zinc, copper, coal, gold, iron, etc., with 33.5 Gt (37 billion st) of proven reserves and more than 51.7 Gt (57 billion st) of potential resources. Iran is ranked among the 15 major mineral rich countries (1). In accordance with the statistics published by Statistical Center of Iran (SCI), there were 5,316 active mines and 84,922 employees in the whole country in 2012-2013 (2) and, according to the statistics published by Central Bank of Iran (CBI) in 2011, the share of this sector in the gross domestic product (GDP) of the country was 1.2 percent (3)."

Jun 1, 2016

By Connor Langford, Murray Gant, Ken Massé

For public organizations, preparing accurate project cost estimates is a critical component in capital project planning. Project delivery methods provide a structured approach to moving projects through the design and construction lifecycle, and typically use cost estimates as key inputs at each stage to determine if the project will advance. As design stages can occur years or even decades before construction contracts are awarded, estimates need to make reasonable assumptions about how the work may be executed (means and methods) as well as potential future market trends so that appropriate values for material pricing, labour costs, escalation, and owner’s costs can be included. This process is challenging enough during stable markets, as historic trends can often be misleading and require a suitable understanding of economic factors to use appropriately. When you mix in the market volatility that has been observed since 2020, developing accurate project cost estimates becomes even more challenging. In cases such as this, having a structured approach to cost estimating that includes an adequate risk-based reserves cannot be overstated as it provides the basis for ongoing project decisions. This paper explores some of the historic and more recent market trends that have impacted key aspects of project cost estimates for capital project planning. It also provides recommendations on how to develop cost estimates for infrastructure projects, with examples from Metro Vancouver, which plans for and delivers regional-scale services to 2.6 million residents. A brief commentary on the use of escalation clauses in contracts is also presented.

Jun 13, 2023

By T. A. E. Breen

A new high intensity grinding technology has been developed and is now being commercialized by Hicom International of Australia. This has led to the development and manufacture of Hicom 120 grinding mills which are now being sold internationally for a range of mining industry applications. The first commercial process application has been for the diamond sector, where the ability of the mill to remove host kimberlite rock by attritioning, with no damage to the thereby liberated diamonds, is seen to be a most beneficial attribute. There are, however, many other mineral industry applications for this mill.

Jan 1, 1999

By J. W. Keck

Pilot plant grinding and concentration test results indicate that conglomerate native copper ore can be ground and concentrated using conventional techniques. Single stage autogenous grinding and rod mill-ball mill grinding required the same amount of energy far the required comminution. Metallurgical results were comparable for both types of grinding investigated.

Jan 1, 1973

By Raymond A. Bradbury

Martin County Coal Corporation's operations are located on Wolf Creek in Martin County in the eastern part of Kentucky. The mining complex was started in 1971 and has grown to a 2.273 Mt/a steam coal operation. All of the production goes to Duke Power Company's Belews Creek electric generating station in North Carolina. Production comes from four seams that are mined by deep and surface mining methods. Surface mining accounts for 55% of the production and the remainder comes from 2 underground mines. Continuous miners are used exclusively underground. The preparation plant was originally designed to take coal at the rate of 907 Mt/h but that has gradually been increased to 1134 Mt/h. Other cleaning equipment includes Daniels DMS vessels, Model 77 Deister tables, 355.4-mm R. & S. Hydro- cyclones, Krebs 254-m classifying cyclones, Daniels froth cells and in 1980, 3 Krebs 508-mm heavy media cyclones were added to recover some lost and misplaced material. CMI centrifugaldryers and a Hey1 & Patterson size 100 thermal dryer are also part of the coal preparation equipment.

Jan 1, 1981

By Martin Langenderfer, Catherine Johnson, Alexander Douglas

Mine haul roads degrade rapidly due to extreme loads on sub-optimal construction materials. Unmanned aerial vehicles (UAV) are suited to quantify large-area road-network conditions, such as surface roughness, defects, and grade to optimize remediation of poor conditions and reduce overall costs. Mine haul roads present unique challenges, such as material type and edge characteristics, to automatic road detection that often fail, requiring manual road input. This research proposes a new method for analysis using the road center determined by principal curve analysis of a haul truck’s Global Navigation Satellite System (GNSS) traces; analysis grids were created from this center line. A dense point cloud from UAV photogrammetry was generated, and multiple linear regression analysis was conducted on each individual grid. The root mean square error in each grid indicates the surface roughness, and the change of slope between grids indicates the road grade inconsistencies. This method was applied to 26 road sections, and the results were validated by images taken from the truck operator’s vantage point. Critical defects were identified including excessive pothole formation, corrugation, depressions retaining water, and narrowing of travel lane. The results demonstrate this is a valid method of road identification and quantification of road defects at a mine site.

Dec 19, 2023

By Eugene A. Lang

Mr. Chairman, ladies and gentlemen. As a member of the uranium and coal producing community, I am pleased to participate in a session dedicated to a look at these and other mineral markets.(title slide) before sharing some of my thoughts with you, let me tell you a little bit about rocky mountain energy company. It was established as a subsidiary of union pacific corporation in 1971 with responsibility for coal, uranium, and industrial minerals. We participate in four coal mining operations and a uranium mine and mill all in Wyoming, and an aggregate and an abrasive operation in Utah.

Jan 1, 1984

By James J. Scott

In 1910 the United States Bureau of Mines was created. It was the outgrowth of a social problem stemming from the fact that 25,000 men were killed in coal mining accidents for the period 1900-1910. Something had to be done and congress responded to the people's demands by creation of this new regulatory agency. At that time mine operators felt the new agency was too strict but nonetheless new rules were developed and enforced and results were obtained by the industry which reduced fatal accidents to less than 250 per year by 1970.*Social reaction by the general public brought about legislation which created the Federal Coal Mine Health and Safety Act of 1969 This legislation was a direct reaction to the Farmington Disaster. Operators and miners alike said "we cannot operate under this law. It is too strict, requirements are unrealistic, production will suffer, .there will not be any improvement in health and safety, etc." Consider the facts: 1. Health and safety have improved. The 1972 frequency and severity rate was the best ever for the bituminous coal mining industry, Figure 1. 2 .Production per manshift has dropped in underground coal mines. For example, in West Virginia from near 16 tons/m.s. in 1967 to nearly 11 tons/m.s. in 1971-72. However, not all of this loss can be attributable to the Act, but certainly some is. (2) The betterment of the safety of coal mining was a prime motivation behind the coal law and from that standpoint the law has been partially successful, but the loss in productivity has been a real burden to the mine operator. Everyone should recognize that the law says little in regard to production--it only relates to health and safety. Production is management's responsibility.

Jan 1, 1973

By S. G. Sawyer

The Pittsburgh Safety and Health Technology Center (PSHTC) of the Mine Safety and Health Administration (MSHA) provides engineering and scientific support to the inspectorate personnel of MSHA. One of the Center's myriad roles is to assist in the investigation of mining accidents, especially those involving fatalities. Center personnel utilize forensics to help uncover the causes of accidents and to make technical recommendations on the prevention of future similar mishaps. To exemplify a typical forensic investigation, this paper documents the methodology used in determining the reasons for a boat sinking, which resulted in a double fatality on a mine company pond.

Jan 1, 1997

By T. A. Farr, I. A. Gibbs, F. Guevara, S. R. Simms, G. Nojima

This paper describes an installation of a medium-voltage adjustable frequency motor drive (AFD) on a high starting torque regrinding mill. This type of application is typically found in the mineral industry dealing with hard ore. The AFD electrical architecture is introduced from line to load. The type of closed loop encoder feedback motor control algorithm is briefly described. The results of the AFD motor identification auto-tuning are compared against the manufacturer’s supplied data. The motor drive performance results are shown for pre-ramp DC fluxing, high starting torque with overload current, excessive load torque stall condition, and blocked rotor. The instrumentation and arrangement for the two watt-meter method to capture low frequency data are presented. The data shown is from the input power quality meter, the AFD computer tool, the output motor protection relay, an oscilloscope, and load shaft connected strain gauge (rotating telemetry for torque assessment). These types of high starting torque constant torque loads are found in mining and process industry applications employing AC adjustable frequency drives. Using field results should help demystify the use of voltage matching output transformers in AFD applications including constant torque loads

Mar 2, 2022

By Staff

In 2012, the estimated value of mineral production increased in the United States for the third consecutive year. Production and prices increased for most industrial mineral commodities mined in the United States. While production for most metals remained relatively unchanged, with the notable exception of gold, the prices for most metals declined. Minerals remained fundamental to the U.S. economy, contributing to the real gross domestic product (GDP) at several levels, including mining, processing and manufacturing finished products. Minerals? contribution to the GDP increased for the second consecutive year. Trends in other sectors of the domestic economy were similar to those in mineral production and consumption rates (Table 1). After continued decline following the 2008-2009 recession, the construction industry began to show signs of improvement late in 2011 and throughout 2012, with increased production and consumption of cement, construction sand and gravel, crushed stone and gypsum, mineral commodities that are used almost exclusively in construction.

May 1, 2013

By J. Morris, R. Sellaro

Petro-diesel is a common collector for coal flotation, but the partitioning of diesel range organics (DROs) in process streams has not been widely studied. Preliminary research suggested that under normal dosing schemes total residual DRO contents in process waters should be limited to the sub-ppm water-soluble fraction (WSF). Further, polycyclic aromatic hydrocarbons (PAHs) should partition proportionately with DROs. The purpose of this study was to confirm these findings in laboratory flotation tests. Total DRO and specific PAH contents were measured in the waters associated with the concentrate and tailings streams. The results show that concentrate waters consistently had higher amounts of DROs than tailing waters. Moreover, the DRO contents in both streams generally increased with increasing diesel dosage. In line with preliminary research, DROs appeared to be limited to the WSF, and PAHs tended to partition proportionately with DROs. Under typical operating conditions, it appears that residual DROs should not present an environmental concern, but conditions should be avoided that allow significant overdosing of diesel.

Jan 1, 2014

By J. Morris, R. Sellaro

El petrodiesel es un colector común para la flotación de carbón, pero la partición de compuestos orgánicos de diesel (DRO por sus siglas en inglés) en corrientes de proceso no ha sido ampliamente estudiada. Investigaciones preliminares sugieren que bajo esquemas de dosificación normales los contenidos residuales totales de DRO en aguas de procesos deben estar limitados a la fracción soluble en agua (WSF por sus siglas en inglés) sub-ppm. Es más, los hidrocarburos aromáticos poli-cíclicos (PAH por sus siglas en inglés) debería segmentarse de manera proporcional con los compuestos orgánicos de diesel (DRO). El propósito de este estudio fue confirmar estos resultados en pruebas de flotación realizadas en laboratorio. Se midieron los contenidos totales de DRO Y PAH en aguas asociadas con los flujos o corrientes de concentrados y relaves. Los resultados muestran que las aguas con concentrados tenían de manera consistente mayores cantidades de DRO que las aguas de relaves. Es más, los contenidos de DRO en ambos flujos generalmente se incrementaban con el aumento de la dosis de diesel. De acuerdo con la investigación preliminar, los DRO parecían estar limitados a la fracción soluble en agua (WSF) y los PAH tendían a segmentarse proporcionalmente con los DRO. Bajo condiciones de operación típicas, los DRO residuales no deberían representar una preocupación medioambiental, pero deben evitarse situaciones que permitan una sobredosis significativa de diesel.

Jan 1, 2014

By S. J. Jung

Determining the correct combination of mix components and water for high-density paste backfills with the transport and deposition properties necessary in a mining operation is a difficult task. Rheologic properties cannot be determined without conducting full-scale pumping tests, and data from existing tests are very limited. The following presents the findings of investigations undertaken to determine if paste backfill rheology can be determined using existing techniques and which mix and system variables have the greatest influence on transport pressure loss. Data from lab-oratory-scale pumping tests were used to produce a rheologic model of flow behavior for comparison, and a statistical analysis was conducted to determine the most significant factors affecting transport pressure loss.

Jan 1, 1994

As noted by D.W. Fuerstenau in his Plenary Lecture at the Conference on Extractive Metallurgy of Gold and Base Metals, Kalgoorlie, Australia, "Com¬minution of solids is surely one of the oldest technologies that, even in this day and age of DNAs, chips and space exploration, continues to challenge our scientific acumen and engineering ingenuity." Thus, the fundamentals of comminution continue to receive a great deal of attention in the literature. This was particularly true in 1992 with the publication of the proceedings from the SME-sponsored symposium, Comminution Theory and Practice. Papers covering topics ranging from liberation to comminution fundamentals to novel size reduction techniques are included in this review. Liberation Liberation continued to be a prime area of research interest, not only in terms of liberation modeling, but also in understanding the basic mechanisms involved in mineral liberation. King (Comminution - Theory and Practice, pp. 3-15) described a method for determining the interphase area between mineral grains. He showed how the mea¬surement of interphase area before and after comminution could be used to determine the presence or absence of intergranular fracture. Lin, Miller and Cortes (Kona, Vol. 7) discussed the use of computed tomography (CT) as a nondestructive means of investigating three-dimensional particle composition. The use of this technique in constructing coal washability curves from CT data was presented.

Jan 1, 1993