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By Ted T. Biddle

The world energy crisis has created a greatly expanded exploration program for energy fuels. The demand for materials required for drilling operations such as barite, which is the primary component of drilling fluids, has increased proportionally. As in the case of many other minerals, existing high grade barite mines are no longer capable of producing the required tonnage. Consequently, exploration and development of lower grade ore bodies has been increased. The need to produce a high quality product at maximum recovery rates, along with the ever changing economics affecting both selling price and production costs has triggered accelerated research programs toward more sophisticated and efficient beneficiation methods. Taking into account the specific gravity differential between barite (4.5) and the normal gangue minerals such as silica and calcite (2.7), gravity concentration methods are the prime consideration with flotation as a scavenging process. Greater emphasis on particle size liberation, size reduction and concentration is also indicated. In order to accomplish these objectives, it has been necessary to revert back to the old adage, "Recover your minerals as soon as they are free."

Jan 1, 1980

By F. Calizaya

A booster fan is an underground ventilation device installed in the main airstream to handle the total quantity of air circulated to one or more working districts. It is installed in a permanent stopping and equipped with airlock doors, a monitoring system and interlocking devices between the main fan and the booster fan. When adequately installed, a booster fan can be used to reduce the main fan pressure, reduce leakage and decrease the power consumption. However, an inadequate installation can increase the likelihood of mine fies and recirculation of air contaminants. This study identifies hazards associated with the operation and maintenance of booster fans. It analyzes the accompanying risks and recommends control measures to reduce those risks to acceptable levels. The ventilation network of an existing coal mine was updated to include a booster fan. The hazards associated with the operation of this fan were identified, the risks analyzed and the esponse to each failure mode established.

Mar 1, 2014

By Roger N. Kust

Because ammonia can form complex ions with certain of the transition metals, such as copper and nickel, it has long been of interest to extractive metallurgists interested in leaching or separating these metals. Although it is a relatively expensive reagent, ammonia is amenable to recycle because of its volatility. In development of processes utilizing ammoniacal leaching or separation schemes, information regarding solution vapor pressures, pH and solubility limitations is needed. There is voluminous literature on ammonia-water systems generated by the urea industry. However, frequently the systems of interest to metallurgists differ significantly in concentrations of ammonia used, the temperatures of interest. Furthermore, the differences arising from the presence of metal values in solution must be comprehended. There is surprisingly little information readily available regarding systems of practical interest to metallurgy. As a result, those interested in ammonia-based processes end up either doing expensive laboratory research to obtain necessary data or overdesigning the process. Another approach to obtaining desired information about ammoniacal systems is to attempt to calculate from first principles the various solution properties. This paper is being presented to illustrate what can be accomplished by estimating the state of equilibrium in an ammoniacal carbonate system from available thermodynamic information making simplifying assumptions when needed.

Jan 1, 1976

By Carl-Henrik Knudsen, Rolf Tore Arnesen, Eigil R. Iversen

Recovery of iron and copper from acid mine drainage was studied in pilot scale at a continuous treatment plant at the mine site of the King's mine in Roeros, Norway. The average load on the plant was 1 m3/h. The process tested in this project is a three-step process consisting of: 1) Fe(OH)3 precipitation at pH 3.5, dewatering of iron sludge and transport to ferric chloride plant; 2) after filtration precipitation of residual metals at pH 9, concentration of metal sludge by flotation; 3) extraction of metals from the sludge with sulphuric acid followed by recovery of copper by electrolysis. The copper could be used for local production of different crafts, but this condition needs a further evaluation. The process economy at a full scale plant is evaluated.

Jan 1, 2000

By A. Tobey Yu

The smelter is the heart of a copper producing operation. Its principal function is to reduce and convert raw copper concentrates and/or leach plant precipitates into blister copper before it is refined. In addition to concentrates and precipitates, typical feed to a smelter also encompasses matte chips, flue dust, flux and lime. By nature, the characteristics of these materials are extremely variable, ranging from sub-micron to lumps, from slurry to dust, from abrasive to corrosive and free-flowing to adhesive. Furthermore, as a result of geological formation, most of the world's open pit copper mines are located in a semi-arid zone, where precipitation is minimal. This particular climate compounds the problem of handling these materials.

Jan 1, 1976

Tables

Jan 1, 1973

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 Yi Luo, Jian Yang, Hua Jiang

Surface subsidence induced by underground coal mining activities, especially longwall mining operations, can cause various problems to interstate highways ranging from structural integrity to drivability to safety. Accurate subsidence prediction, correct influence assessments and effective mitigation measures are the keys to ensuring the safety of highway traffic. The surface subsidence prediction program, called comprehensive and integrated subsidence prediction model (CISPM), was developed based on the principle of influence function method and has been validated with a large number of subsidence measurements. In this paper, the techniques to use the predicted final surface movements and deformations for assessing their influence on the integrity and functionality of highway structures — such as road surface pavements, concrete slabs and transverse joints — vehicle dynamics, comfort level and drivability are presented. A number of mitigation measures to protect the highway structures and to ensure traffic safety are proposed, along with an application case.

By Iga Trisnawati, Fitria Puspita, Himawan Tri Bayu Murti Petrus, Gyan Prameswara, Idi Amin, Andi Nurfaadhilah Ulfah

Laterite ore is a valuable resource due to its high content of metals essential for modern technology, including nickel, iron, and cobalt. However, extracting nickel from laterite ores is challenging due to their complex mineral composition and low nickel concentrations. This study examined the leaching behavior of pre-roasted laterite ore and the effect of roasting on leaching kinetics. The ore was roasted at temperatures of 280°C and 610°C for 3 h, followed by sulfuric acid atmospheric leaching. The results demonstrated that pre-roasting at 610°C significantly enhanced nickel leaching recovery, with up to 93% nickel successfully recovered. The leaching process of pre-roasted laterite ore was found to be controlled by diffusion through the ash layer, with activation energy values of 20.97 and 18.97 kJ/mol for laterite roasted at 280°C and 610°C, respectively. These findings indicate that pre-roasting can improve the leaching performance of laterite ore, potentially leading to more efficient and sustainable nickel extraction processes.

Feb 27, 2024

By Frank A. Jerabek

Pneumatic stowing was first introduced in longwall mining in the middle twenties. Since that time it has advanced through many stages of development, particularly abroad, which have greatly improved its efficiency and contributed to its growing use. Pneumatic stowing originated in coal mining but has also been adopted in metal mining. This paper discusses the techniques of pneumatic conveying of. stowing material and equipment and applications of pneumatic stowing.

Jan 1, 1966

By Ernest F. Giovannitti

A couple of years ago, one of the major television networks produced a series on the environment. One episode in the series dealt with the nation's solid waste problem and some of the research being done to solve it. It was interesting to listen to one researcher who was attempting to develop a glass that when broken would dissolve in water. It was said that using this glass would eliminate over 100 million tons of solid wastes each year. At first glance, it would appear that this research-effort would make a significant contribution to environmental pollution control; however, if one pauses to consider the water, he can see that this solution to the solid waste problem may well contribute to a water pollution problem. The dissolved material must either end up in our surface streams or be removed in waste treatment systems. Either alternative may have a more adverse effect on the environment than the original problem. With today's emphasis on the environment, it is important that the effects of our activities be studied in depth. Then, by properly planning the activity, the adverse effects can be minimized. The coal mining industry 100 years ago was in the same boat, as our glass maker, is today. Unfortunately, it too failed to consider all the effects of its activities and as a result, in Pennsylvania, there are over 5000 miles of streams adversely affected by coal mine drainage. The situation is improving, however, because mine operators are beginning to recognize and accept the methods for controlling coal mine drainage. The purpose of this paper is to discuss the measures for the control of coal mine drainage and to set forth the factors that affect these controls.

Jan 1, 1972

By Brendan Demich, Brendan Macdonald, Timothy J. Orr, Jason Navoyski, Jennica L. Bellanca, William J. Helfrich

Recent advances in computing, rendering and display technologies have generated increased accessibility to virtual reality. Virtual reality allows for the creation of dynamic, high-fidelity environments to simulate dangerous situations and test conditions and to visualize concepts. Consequently, numerous products have been developed, but many of these are limited in scope. Therefore, U.S. National Institute for Occupational Safety and Health (NIOSH) researchers developed a virtual-reality framework, called VR Mine, to rapidly create an underground mine for human data collection, simulation, visualization and training. This paper describes the features of VR Mine, including mine generation, simulated networks, proximity detection systems, and the integration and visualization of real-time ventilation models.

By Charles Kocsis, Pedro Nascimento, W. Patrick Arnott, Samuel J. Taylor

Respirable crystalline silica (RCS) is an inhalation health hazard for mining and industrial work environments and must be monitored. We provide theoretical analysis of real-time measurements for determining RCS mass concentration without the use of filters by using photoacoustic spectroscopy. The suspended dust in the mine air can be continuously sampled by the photoacoustic instrument. A tunable quantum cascade laser is the light source, allowing for determination of interferences such as kaolinite, coal dust, and water vapor. The most useful spectral region is found to be between 11 and 13 μm. Absorption by water vapor, and, to a lesser extent, carbon dioxide, in this spectral region has gaps that allow for quantification of the aforementioned dust species as well as a convenient check on the calibration of the instrument. This work brings photoacoustic measurement of aerosol to the mid infrared range where spectrally dependent light absorption can be used to quantify dust composition and mass concentration.

Jul 31, 2022

By J. K. Whyatt

In situ stress on the scale of a tunnel or mine may be distorted by geologic structures. The resulting variations of in situ stress have a direct bearing on the potential for mining-induced seismicity. New evidence from the Lucky Friday Mine collected by U.S. Bureau of Mines researchers, as well as a review of case studies, demonstrates that in situ stress variations affect the spatial distribution of mining-induced seismicity. Although overcore stress measurements have been useful in these studies, they are too expensive and, depending on conditions, may be too difficult, to use routinely in mapping stress variations. However, information from borehole and raisebore breakouts; deformation of mine openings; and patterns of seismicity, ground control problems, and rock burst damage can be used to build a stress database. This database can then be used in con-junction with maps of mine structure and geology and models of rock mass behavior to build a map of in situ stress variations. Such a map provides a means to anticipate patterns of mining-induced seismicity that are likely to be encountered and, hence, provide a means for planning appropriate measures to ameliorate rock-burst hazards.

Jan 1, 1995

By A. K. Gangopadhyay

This paper discusses the effect of grinding media composition, mineral type and slurry environment on the wear rate of various grinding media (balls). Sufficient wear data have been obtained and correlated with the modes of wear determined from examination of the ball surfaces using scanning electron microscopy. Five modes of wear have been identified to be operative under certain slurry conditions for the various ball compositions studied.

Jan 1, 1984

By Michael F. Werneke

While the use of synthetic polymers for solid/liquid separation is not raw technology (1)(its history goes back to the mid 1950's), its importance has increased dramatically over the past decade. This can be attributed to two major factors. The first of these was a change to mechanized mining (strip mining and continuous underground miners) which resulted in a lower quality (higher reject) preparation plant feed, as well as a higher percentage of smaller size particles in the feed. The second factor has been the greater restrictions imposed by governmental agencies on effluent discharge and solids impoundment, requiring pre-treatment of recirculating water before reuse and treatment of refuse before disposal. Today, synthetic polymers find utility in almost all applications requiring separation of solids from aqueous suspension, including "in-process" as well as waste treatment applications. In spite of the fact that there are over several hundred commercially different flocculants available in the marketplace (2), there are a limited number of chemically different materials available which are useful from a cost/performance standpoint. The potential reasons for using flocculants in a coal preparation plant are summarized in TABLE 1.

Jan 1, 1979

By J. C. Cawley, G. T. Homce

The U.S. National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) conducted a study of mining industry electrical injuries reported to the U.S. Mine Safety and Health Administration (MSHA) for the years 2000 to 2009. The findings of that study are detailed in this paper, and serve to characterize the circumstances surrounding electrical injuries and identify causal factors. The study included three tasks: 1) a direct review of mining industry occupational injury data compiled by MSHA, 2) interpretation of the narrative descriptions available for the injuries (from MSHA data) and 3) a separate examination of fatal electrical injuries. Eight-hundred sixty-five electrical injuries were reported during the 10-year period studied, with 39 of those being fatalities. This makes electrical injuries disproportionately fatal with respect to most other types of injuries in mining. Electrical injury rates were higher in coal mining than noncoal mining and, within the coal sector, rates were higher in underground operations than in surface operations. Of the 865 total cases, electrical and machine maintenance or repair activities were involved in 580 (69%), and electricians and mechanics were injured in 362 cases (42%). Of the 39 fatal electrical injuries, 27 (69%) involved electrical maintenance or repair work, and in 21 of these 27 cases, the failure to de-energize, lock-out and tag the circuit was the cause or a contributing factor. Also, contractor employees had a much greater chance of an electrical injury being fatal than did mine operator employees. The top three root causes for fatal electrical injuries were 1) no or inadequate lock-out and tagging, 2) failure of power system components and 3) contact of overhead electrical power lines by mobile equipment.

Jan 1, 2013

By O. Tranbarger

In aging tunnels, wall and roof deterioration can eventually result in defects that must be detected and repaired to maintain safe structural conditions. In investigating tunnel defect conditions, a specialized FM radar system was developed with a programmable VHF and UHF operating sweep range for optimizing the penetration and measurement capabilities. The new FM radar technology was tested in two aging brick-lined tunnels in New York City. Test results showed that FM radar signals could penetrate eight courses of water-saturated brick and that the original steel liner outside the tunnel walls was intact.

Jan 1, 1985

By R. A. Wyman

What unusual features are there about finding, winning, and using the industrial minerals of Canada which may be of interest and yet not widely known. Have you, for example, ever wondered where the raw material for those distinctive greenish grey statuettes, so readily recognizable as Eskimo carvings, comes from? Although stone suitable for carving is obtained at several northern locations, in recent years the Federal government, the Quebec government, and one or two private companies have shipped supplies of various rock types from other sources to central distribution points in the Canadian north for the express purpose of providing Eskimo artists with raw materials for carving. Canada is well endowed with industrial minerals, the extent and variety of which may be observed by a perusal of Table 1. In this table, materials currently produced are shown in the left-hand column; materials which are bordering upon economic viability are listed in the middle column; and materials which have been found in Canada in possible exploitable quantity, but for which [ ]

Jan 1, 1970

By Jr. Smith

Industrial minerals are just other rocks, except for the unique characteristics that make them useful in an industrial process. There is not a ready market for this type mineral and one or more uses must be developed to sustain production. The name "olivine" is a generic term used to indicate a group of orthosilicate minerals in a solid solution series, with forsterite (Mg2SiO4) and fayalite (Fe2SiO4) as endpoints. Since neither is found alone in nature, the mineral is always a combination of the two. The commercial deposits are high in magnesium and on the high end of the melting scale in the series. The name comes from the olive-green color.

Jan 1, 1992