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By A. Lashgari, V. Kecojevic

This paper presents research on the environmental impact of digging and loading equipment used in surface coal mining. Environmental impact was assessed through the measurement of equipment exhaust and dust emissions, and sound level. In this study, exhaust emission refers to carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx) and volatile organic compounds (VOCs). Dust generation refers to fine particles (PM2.5), inhalable particles (PM10) and total suspended particulate matter (TSP). Sound level refers to the sound pressure level at different distances from the equipment. Modeling of the environmental impact of digging and loading equipment was conducted using the Microsoft Visual Studio.NET software package. This research was a part of a broader project involving the development of a software system for the selection of productive, cost-efficient and ecofriendly mining systems, sponsored by the Appalachian Research Initiatives for Environmental Sciences (ARIES). This research may assist mining professionals in quantifying the environmental impact of digging and loading equipment, and developing strategies for reducing the overall impact of such equipment in surface mining.

Jan 1, 2013

By T. Faulkner, S. A. Richards

"The Scale-Distance formula is one of the primary means of determining the maximum amount of explosives that can be safely detonated at one time by a single delay. This paper describes a method of applying the Scale-Distance formula to the entire mining area using gridded surfaces. Using this technique, the operator can better determine the economic impact of nearby structures on the mine plan. INTRODUCTION As the surface mining of coal and stone encroaches near populated areas, precautions must be taken to minimize blast vibration damage to protected structures. The common method employed to minimize vibration damage is not to reduce the total amount of explosive in the hole (which would negatively affect fragmentation), but rather to introduce delays to reduce the amount of explosive detonated at any point in time. The Scale-Distance formula, an industry-accepted standard, may be used to calculate the maximum weight of explosive that can be detonated at one time without damaging the structure. This information may then be used to determine the number of delays required for each hole. Detonators make up a large part of the cost of blasting. At roughly $15 per detonator an additional detonator in the hole can be significant. It is normal to set off hundreds of holes at in one shot. An additional detonator in each hole can cost additional thousands of dollars per shot. The number of detonators is also a function of the depth of the holes and the hole spacing. Being able to accurately forecast the economic impact of blasting near structures improves a company’s ability to make informed decisions on how to approach property owners. Operators basically have three options when dealing with property owners: 1. Buy the property and blast without restriction 2. Negotiate with property owner for a waiver to allow unrestricted blasting 3. Comply with the legal blasting restrictions This paper proposes a method for the engineer to forecast for all points in the proposed mining area the impact of nearby structures upon the blast design. Being able to create a contour map and ultimately estimate the number of delays required for the entire forecasted mining area, the engineer can create accurate economic forecasts of the cost of blasting. The objective is to reduce the level of uncertainty in the forecast of the blast component portion of the forecast."

Jan 1, 2016

By I. H. Douglas

All grade control methods in use currently by the mining industry are imprecise. The methods suffer from being locally inaccurate, leading to are loss and contact dilution. An ore/waste indicator variable can be used to predict the probability of ore occurrence at a given location, Po. Then, an ore grade Zo for an ore location and a waste grade Zw for a waste location are obtained. The expected revenue is calculated at each location, based on its probability of being are or waste, the corresponding grade, and on the cost of mining and processing the ore or the waste. Finally, the decision of whether to recover the block is based on the expected revenue value for that block. The method is illustrated with an example taken from the Jerritt Canyon district in northeastern Nevada.

Jan 1, 1994

By Zhiyuan Shen, Dan Zhao

The abstract discusses the importance of reliable mine monitoring systems for preventing accidents. It focuses on diagnosing ventilation system failures caused by roadway faults that alter airflow resistance. The paper proposes using an improved Support Vector Machine (SVM) method to identify the fault location based on changes in air volume detected by wind speed sensors. The approach involves building a sensitivity 0-1 matrix and establishing a roadway fault scope library. The improved SVM method is tested on the Daming coal mine, demonstrating its effectiveness in diagnosing fault locations, reducing training time, and improving accuracy compared to traditional SVM.

Apr 5, 2022

By E. Bonates

Dispatching systems have attracted considerable attention in the last years due to substantial gains in productivity achieved through their implementation. These systems will be extensively used in the future by mine operators as a means of optimizing productivity. This paper describes a computer simulation model designed to study the feasibility of continuously dispatching trucks in open-pit mines based on different operating procedures. The system developed is semi-automated and performs an active role by suggesting to the dispatcher the best assignment according to each specific circumstance. It is modeled based on an advance-clock increment to reduce computing time and allows the insertion of heuristic dispatching policies and equipment real-locations when breakdowns occur. Dispatching procedures taking into account long-term production objectives are considered in system development.

Jan 1, 1988

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 Richard A. Thomas, Liming Yuan, Wei Tang, JOHN SOLES

Lithium-ion battery applications are increasing for battery-powered vehicles because of their high energy density and expected long cycle life. With the development of battery-powered vehicles, fire and explosion hazards associated with lithium-ion batteries are a safety issue that needs to be addressed. Lithium-ion batteries can go through a thermal runaway under different abuse conditions including thermal abuse, mechanical abuse, and electrical abuse, leading to a fire or explosion. The NIOSH Mining program is conducting research to prevent and respond to lithium-ion battery fires for battery electric vehicles in the mining industry. In this study, experiments were conducted to investigate the effectiveness of different suppression systems including dry chemical, class D powder, and water mist for lithium iron phosphate battery pack fires. The effects of activation time and release time of the water mist system on the suppression of lithium-ion battery fires were studied. The results of this study may be helpful for developing strategic firefighting and response plans for battery-powered vehicles used in mining.

Feb 17, 2024

By Lewis J. Patterson

In the period of time allotted to this paper, an attempt will be made to cover a great deal of territory, figuratively speaking, as far as our experience with ammonium nitrate is concerned. In giving this subject the "broad-brush" treatment, it will be necessary to generalize on the major points which at the same time will permit me to avoid, to a great extent, any involvement in the purely technical and theoretical aspects of blasting. The practice of theorizing before a new idea is tried has practically been discontinued in our organization simply because experience has shown that, almost without exception, theories have fallen aside as some new development takes its place. In regard to blasting, logic and experience seem to have little place in this phase of quarry operations. As the use of low cost blasting agents was introduced in our operating practice, a man who had no previous experience in the field of blasting but with sound knowledge in safety procedures was given the responsibility of supervising the drilling and blasting operations. A total lack of experience is not ordinarily recommended as a prerequisite to assuming the responsibilities of a supervisory position. However, in this case it was obviously a wise decision because there were no pre-conceived ideas as to what techniques would or would not be successful.

Jan 1, 1958

By A. Dell’Era, E. Ciro, C. Lupi

The paper explores the recovery of indium via electrowinning from sulfate baths, focusing on the impact of different cathodic supports (AISI 316L and nickel) on process parameters such as electrolyte composition, current density, and temperature. The study compares productivity, morphology, and structure of indium deposits on both cathodes, finding that nickel cathodes generally yield better results.

Nov 1, 2023

By Jonathan G. Price

The 2011 report titled ?Energy Critical Elements: Securing Materials for Emerging Technologies? by the American Physical Society?s Panel on Public Affairs and the Materials Research Society surveys potential constraints on the availability of these elements and identifies five specific areas of potential action by the United States to ensure their availability: 1) federal agency coordination; 2) information collection, analysis and dissemination; 3) research, development and workforce enhancement; 4) efficient use of materials and 5) market interventions. Energy-critical elements (ECEs) are a class of chemical elements that currently are critical to one or more new energy-related technologies. A shortage of these elements would significantly inhibit large-scale deployment, which could otherwise be capable of transforming the way in which energy is produced, transmitted, stored or conserved. The report addresses elements that have not been widely extracted, traded or used in the past, and therefore are not the focus of well-established and relatively stable markets (such as carbon in coal or uranium as fuels, copper, aluminum, nickel and iron, all of which are clearly vital in energy applications).

Jan 1, 2011

By A. G. Provost

On April 3, 1981, Harrison Western Corporation was awarded a contract by Amax Alloy - A Division of Amax Inc., to sink the Henderson #5 ventilation shaft. The project was located on the Henderson Mine site 88 kilometers west of Denver near the town of Empire, Colorado (Figure I). The Henderson No. 5 Shaft, located in an Alpine environment at an elevation of 3145 meters, was a 9.8 meter diameter concrete lined shaft with a total depth of 793 meters. Work started and continued with Harrison Western employees until January 15, 1982. At that time, Amax made the decision to continue the shaft-sinking with their own labor, and with Harrison Western providing supervision under a management service contract. Shaft sinking continued under this arrangement to October 1, 1982, at which time Amax put the Henderson No. 5 project on standby status until further notice.

Jan 1, 1986

By Yuanhong Qi, KUN CUI, Tao Fu, XUNFU WANG, Yingyi Zhang, Jie Wang, Junmao Qie

Indonesia is the world’s largest supplier of nickel ore, with its nickel laterite resources mainly distributed in the Moluccas and Sulawesi regions. However, there is scant research on the mineralogical characteristics of nickel laterite deposited in southeast Sulawesi, Indonesia. This study aims to investigate the mineral phase structure, chemical analysis, thermal properties and element distribution characteristics of the middle and lower part of the rotten rock zone located in the southeast Sulawesi ophiolite belt.

By P. Malozemoff

Discussion by P. Malozemoff I have no objection to using mathematics in the value appraisal of properties. The factor that is not emphasized in the paper is that very few important properties have a lifetime that reflects the initial ore reserves of the property divided by the rate of production adopted. In the majority of cases, major properties mine out several times the initial reserves. How much more will be mined out is not known, and only exceptionally gifted geologists can predict that additional reserves will be found. There is the further factor of metals price, which, over the long term, is not predictable. Another factor vitiating making calculations on initially established ore reserves is the speculative nature of exploration success. In my judgment, the life of a property, in addition to an established ore reserve, should include ample time for exploration to find additional reserves. The likelihood of additional reserves is based on the geological promise of the general area where the mine is established. This is especially important because of various risk factors associated with small orebodies, the economic life of which is about five to seven years. In underground mines, it is not economic to develop reserves beyond a certain depth, so the life of initially established reserves must be limited. In these cases, it is especially important to have a good geological understanding of the orebody and its continuity. To accommodate these concepts and present proof of economic soundness for a mining enterprise, a mathematical analysis should yield a life long enough to allow exploration and the development of additional reserves that would ensure a longer mine life and a more profitable result.

Jan 1, 1994

By E. J. Karges

The use of pulverized coal for generating power and performing industrial processes has made an important contribution to our industrial economy during the past half century. Actually, the burning of coal in powdered form is a subject that has held the attention of engineers for a century or longer. Its widespread use, however, is comparatively recent, As early as 1866 patents were granted to Messrs. Whelpley and Storer for a method of feeding pulverized coal into a furnace as an auxiliary to the grate fuel. In the many tests made during the subsequent years with various kinds of apparatus, the experimenters were handicapped in not getting the coal fine enough to obtain complete combustion and to prevent excessive formation of slag.

Jan 1, 1965

By W. C. Yates

Lack of visibility from cabs of the large haulage trucks used in open-pit mines has become a serious safety problem. This Anaconda research program was conducted to develop a low-cost system for alerting haulage truck operators of the presence of small vehicles in their blind areas. Several systems, developed and tested to help solve this problem, are summarized and evaluated in this paper. As the size of the haulage trucks used in large open-pit mines has increased, so have the blind areas. Mine utility vehicles, pickup tucks and cars become concealed within these blind areas and, thus, become a serious safety hazard. Figure 1 shows the typical blind areas of a 150-ton haulage truck. The areas of greatest concern are those at the rear center and front right corner of the truck. It is within these areas of "no visibility" that numerous small vehicles over the years have been crushed by the large haulage trucks at various mine sites. Although the occupants in most instances, have escaped the vehicle before it was destroyed, injuries and deaths have occurred. The accidents, in most cases, were attributed to negligence or carelessness on the part of the driver of the smaller vehicle, but the problem of limited visibility still exists, and a solution is needed.

Jan 1, 1982

By Norman Haber

The Haber Gold Process (HGP) is a proprietary. hydrometallurgical extraction methodology that was developed in 1983-1984 by Norman Haber and Dr. John Lee of Haber, Inc., a small public company in Towaco, New Jersey specializing in hydrochemical process development for precious metals. It was pilot tested repeatedly in 1985 at our pilot plant in Tombstone, Arizona, with different types of gold bearing mineralization. Both Pincock, Allen and Holt (USA), and PA Technology (Australia) were involved with some of these pilot tests. The ores tested included easily cyanide-extractable oxide type gold ore from Australia, marginal heap-leach type ore from Cripple Creek, USA, and a hematite bearing ore from California. In all cases, extraction time was 6 hours or less yielding 90-99% recoveries of assayed gold values. The HGP operates as a lixivient which parts the gold from the rock matrix, yielding gold in solution in a fully recoverable form. Both precipitation methods, such as zinc participation or Carbon in Leach systems ( or Carbon in Pulp) have been shown to be feasible with this technology for the recovery of gold from the pregnant solution. Both batch vat leaching as well as continuous processing are realistic for use with the HGP. It has also been considered that the HGP might also benefit heap leaching due to several advantageous factors over cyanide. One such consideration is that the HGP can operate effectively with acidic ore types. The use of cyanide with such ores often requires attention to pH and neutralization with lime. This tends to reduce and even clog the permeability of the leach bed.

Jan 1, 1998

By T. W. Martin

In 1973 the percentage of total coal production mined by surface methods in the United States again increased, reflecting a long term trend. Barely three decades ago less than 10 percent of the U.S. coal was produced in this manner. Last year surface coal mines produced 299 million tons, 50.7 percent of our nation's coal. At present there are about 2450 strip mines producing coal in 23 states. While accident rates for surface coal mines are less than underground coal mining rates, surface coal mining is certainly one of the more hazardous occupations. Figure 1 shows the injury rates (fatal and non-fatal accidents) of major U.S. industries. Note that surface coal mining is more hazardous than all other industries except contract construction. Accident rates are about the same as the contract construction industry which uses similar equipment. A limited amount of detailed data was available on elements of surface coal mining jobs and this lack of compiled information made it difficult to assess the significance of the conditions contributing to accidents and to make recommendations that would reduce accident frequency. Therefore as part of the Bureau of Mines continuing research efforts related to the health and safety of the coal miner, a contract was awarded to Theodore Barry and Associates of Los Angeles to conduct an "Industrial Engineering Study of Hazards Associated with Surface Coal Mines."

Jan 1, 1974

By K. J. Ma, L. Ma, J. Stankus

The paper’s intent is to evaluate pumpable foamed cementitious mine seal material by determining the shear strength of a generic foamed cement in the laboratory. The tests were conducted on three scales: small-size specimens, consisting of cylinders 4 in. in diameter or 3-in. prisms; double shear medium- size specimens, measuring 13 in. by 10 in.; and large-size specimens, measuring 6 ft by 4 ft by 4 ft. The small-specimen shear tests resulted in average peak and residual shear strengths of 128 psi and 56 psi, respectively. These values are fairly consistent with published shear strengths of foamed cementitious material. However, the other two types of shear tests did not achieve the shear strength of a typical pumpable foamed cementitous mine seal material. Based on the test results, the paper concluded that the structural analysis of cement foam seals should be based on their residual shear strengths, approximately 20 psi, determined from small laboratory-scale tests of the cement foam/concrete or rock interface, and not be based on their peak strengths.

Jan 1, 2015

By Peter Halbach

Cobalt-rich ferromanganese crusts are one type of the two oxidic metallic mineral resources in the deep ocean that incorporate metals supplied and transported from both land (aerosols, continental run-off) and sea sources (oxygen-minimum zone, hydrothermal alteration of the oceanic crust). The substances directly precipitate from cold seawater under more or less oxic conditions and form thin layers (2 up to 25 cm thick) on hard substrate rocks like volcanic hyaloclastites, weathered basaltic rocks and/or carbonate-fluorapatite; in the crusts many metals therefore exist in the highest state of oxidation. Deposits of the Co-rich ferromanganese crusts are found throughout the global oceans on the flanks, terraces and summits of seamounts and submerged volcanic mountain ranges and platforms, where the ocean currents have kept the seafloor more or less free of sediment for millions of years. The process of hydrogenetic precipitation is basically an inorganic colloidal-chemical and surface-chemical mechanism. Elements in seawater may occur as dissolved hydrated ions or as inorganic as well as organic complexes which in general have either a positive or a negative surface charge depending on the pH of the respective aqueous environment. Those complexes may form hydrated colloids that interact with each other and with other dissolved hydrous metal ions. Hydrated cations such as Co, Ni, Zn, Sn are, for example, attracted by the negatively charged surfaces of colloidal hydrous Mn-oxide particles, whereas hydrated anions (e.g. oxyanions) and elements forming larger complexes with low-charge densities (e.g. U, As, Th, Hf, REE) are attracted by the slightly positively charged hydrous Fe oxihydroxide particles.

Jan 1, 2008

By J. Hanna, H. R. Gonzalez

Discussion by N.L. Hargett Dear Dr. Hanna: As discussed in our phone conversation, we are enclosing a suggested revision to the paper, "Application of Bentonitic Clays in Suspension Fertilizer Formulations," published in MINERAL & METALLURGICAL PROCESSING, May 1990. The revision will replace the second paragraph in the article. The reason for the revision is that suspensions have decreased in market share since 1984 and at present comprise an estimated 25% to 30% of fluid mixtures. This represents 6% to 7% of all fluids and only 2% to 3% percent of all fertilizers. Based on national surveys conducted by the Association of American Plant Food Control Officials (AAPFCO), suspensions comprised an estimated 25% of all fluid mixtures in 1974, 33% in 1976, 35% in 1980, 40% in 1984, and 36% in 1988. Revision to "Application of Bentonitic Clays in Suspension Fertilizer Formulations." Suspension fertilizers are an important segment of the fertilizer industry in the United States. Suspensions allow higher concentrations of nutrients (N, P2O5, K2O) than clear liquid solution fertilizers. K20 content of solutions is limited to about 10%, while suspensions can contain more than 30% K2O. Suspensions can tolerate greater variations in temperature than solutions. In suspensions, if crystallization occurs, the crystals can remain suspended in a clay jell instead of settling as they would in solutions. Solubility is not a limiting factor in suspensions, since complete solubility of phosphate is not required. This allows a wider range of phosphate materials to be used. Also, materials commonly used in formulating suspensions are less expensive and more widely available than those for clear liquids (Getsiner et al., 1984).

Jan 1, 1992