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By Jr. Pitts

Elevation of surface charge density on colloidal particles in the presence of a high potential electrostatic field is demonstrated as a viable technique for preventing the accumulation of solids in solvent extraction circuits. The effect of the technique is manifest by relative turbidity measurements between pregnant leach solution and raffinate, by changes in the character of the sludge accumulations, by alteration of the zeta potential of particulates, and by a general reduction in the mass of solids.

Jan 1, 1992

By B. M. Ghadiali, J. B. Putnam, T. P. Smirnoff, M. A. Elioff, P. F. Ryan

Geotechnical investigations for the Mid-City Extension of the Los Angeles Metro revealed high concentrations of toxic hydrogen sulfide (H2S) gas as well as methane. Testing techniques employed to determine the extent of gasses, and to identify potential treatment measures, included gas sampling with cone penetrometers and soil-gas extraction with air injection testing. A gas reservoir model was developed to predict inflows into excavations. Other studies included a hazard evaluation and a general data search for other H2S occurrences and geologic conditions that could facilitate the accumulation of H2S. The paper describes the investigations and proposed design and construction alternatives.

Jan 1, 1995

By C. Pomeroy, J. Weyer, J. Brune

"Mining began in the Erzgebirge (“ore mountains”) region of Saxony, Germany more than 800 years ago, and extensive underground workings cut through the entire area. Some of these old workings are still used today: not for production, but for offering an underground venue for research, tourism and university teaching. One example is the Reiche Zeche mine at the Technische Universität Bergakadamie Freiberg which hosts one of the oldest mining engineering programs in the world. It is imperative to keep all active mine workings well ventilated to make the mine safe for students, visitors and researchers. Since the mine workings at Reiche Zeche are so vast, extensive and, to a large extent unexplored and unmapped, it has been difficult to provide a complete, functioning and adequate mine ventilation model for this mine that accounts for all known and unknown leakage air flows. Researchers at the Colorado School of Mines have cooperation with their colleagues at Freiberg to establish a mine ventilation network model based on a limited number of air readings in known and accessible drifts. In order to balance the measured air quantities, leakage flows were quantified and mapped by comparing input and output flows of mapped drifts, and modelled using Ventsim Visual, a powerful visualization software package. The resulting mine ventilation model is used to locate and quantify the leakage air flows and to examine how much air is lost in each area. With this model, ventilation changes and improvements underground can be documented reflected in the model. This enables the Bergakadamie Freiberg to project air changes required for scientific experiments and to set up mine ventilation in specific areas and for specific needs. The model also enables better ventilation control and monitoring than before. Finally, the model can be used to predict ventilation changes and escape way contamination in case of a fire, ground fall or inundation in the mine. The latter becomes important as the lower mine workings are often flooded during spring runoff, which has created uncertainty about mine ventilation in the past. HISTORICAL BACKGROUND The discovery of silver, lead, zinc, tin and other valuable metal ores in the Erzgebirge region of Saxony, Germany began in the12th century and started a mining boom than lasted for centuries. Surface mines quickly developed underground to access the higher grade veins. Explored by the early geologists and driven by the ingenuity of the miners, the underground works expanded vastly throughout Freiberg and the surrounding region. Development followed the highest grade veins, and engineers developed solutions to drain water and provide limited ventilation to the underground workings. Still, engineered and planned ventilation was usually not a priority in the development of a new drift, which today makes ventilation modeling a significant challenge."

Jan 1, 2015

By N. Sloan Dworian, Alyssa Smith, Ian Kellogg

Many studies have utilized magnetic susceptibility data to fingerprint porphyry copper centers; however, usage of magnetic susceptibility data to identify trends in a Climaxtype molybdenum porphyry deposit is limited. To better understand potential petrophysical signatures in a Climaxtype Mo porphyry deposit, magnetic susceptibility data was gathered at regular intervals from core holes across the Climax Mine, targeting major lithologies and styles of alteration. Preliminary analysis suggests that there are quantifiable patterns which may correspond with the mineralizing intrusions. This data can complement current mapping and exploration techniques to identify Climax-type molybdenum porphyry centers and likewise further the exploration potential for this deposit type.

Feb 22, 2026

By Fang-tu Wei

The purpose of developing this system is to monitor the operating status of the fully mechanized mining system in order to raise it's reliability. The completely mechanized coal mining system is a complex dynamic system, involving many sub-systems. It is the key of the mining process as well as a connected system composed of each working procedure. Any hitch in breaking, loading or transporting will interrupt the mining process. The analyses of the operating data has proved that the reasons causing the interruption of the extracting processes mainly come from the inner of coal face. Hence, after the installation of the MINOS system in England, the delays of belt conveyor sub-system were reduced. But the production increment was not as much as expected.

Jan 1, 1986

By Brendan Demich, Brendan Macdonald, Timothy J. Orr, Jonathan K. Hrica, CASSANDRA L. HOEBBEL, Jason Navoyski, Jennica L. Bellanca

Haul truck fatal accidents and injuries continue to be a significant concern for the mining industry. However, the availability of high-quality training materials continues to be limited. Near-miss incident accounts, if packaged well, could help fill this gap, because for every fatality, there are hundreds of reportable accidents and thousands of undocumented near misses. Researchers from the National Institute for Occupational Safety and Health (NIOSH) collected detailed accounts of 21 near-miss incidents in virtual interviews with mineworkers at surface mining operations across the country. From these interviews, researchers created four simulation videos using the Unity game engine. The simulation videos bring these events to life through first-person retelling and various visual perspectives of actual events. Each video exemplifies a critical safety message and a common haul truck hazard. This paper describes the process of taking narratives and turning them into impactful visual stories using graphic simulation. NIOSH plans to co-release these simulation videos with the Mine Safety and Health Administration (MSHA) to the mining industry to raise awareness and ultimately help reduce haul truck-related accidents and fatalities in mining.

Jun 1, 2023

By L. W. Laage

Throughout recorded history, underground fires have plagued mining operations. Compared with other hazardous situations in underground mining, a fire can become a global problem by swiftly spreading deadly carbon monoxide and other products of combustion (POC's) throughout the whole mine, often without warning. Experience has shown that when fires are detected and located in their early stages, they are much easier to control and proper escape routes can be more intelligently selected. Recent advances in sensor and data communication technology have made reliable mine fire .detection system installations possible. Unlike building construction. in a mine, it is impractical to install detectors at every desired location. Abandoned workings and unsafe locations preclude sensor installations from both safety and economic standpoints. The net effect is that some fires are detected and located early while the location of others, even if detected early, remains unknown too long for effective evacuation and fire fighting.

Jan 1, 1989

By A. A. Densmore

Telluric Current is that portion of the electric field observed at the surface of the earth which is of an alternating nature, and which is related to solar activity and events in the ionosphere. The primary electromotance which drives the telluric current is the result of the induction process associated with time variations in the earth's magnetic field. The relationship between the electric and magnetic components of this electromagnetic field depend upon the conductor. For our purposes, we are dealing with frequencies f in the range

Jan 1, 1972

By Yao Zhou

Under the United Nations Convention on the Law of the Sea (UNCLOS), the international seabed area (Area) and its resources are the common heritage of humanity (CHH). Patent rights can be incompatible with the CHH doctrine and its underlying principles because patent holders might charge unjustifiably high prices to license patented technology for exploring and exploiting the Area’s resources (creating a "patent holdup" situation), might choose not to license, or might license exclusively when doing so would contravene CHH principles. However, a reasonable patent licensing regime can contribute to sharing the benefits derived from the Area and promote environmental sustainability. Provisions of the UNCLOS that stipulated compulsory technology and financial transfers were removed in the 1994 Agreement relating to the Implementation of Part XI of the UNCLOS (1994 Agreement), but to promote equity and sustainability I propose a voluntary licensing regime modeled on the concept of reasonable and non-discriminatory patent licensing (RAND) that has been used in other contexts. The International Seabed Authority (ISA) or another entity will need to coordinate and promote this licensing regime through governance of intellectual property (IP) derived from the Area. This proposed approach can better effectuate the CHH doctrine and its underlying principles.

Sep 1, 2014

By Thomas Jancic

Two of the open-pit, copper-molybdenum mining operations of Duval Corporation are located in the foothills of the Sierrita Mountains approximately 30 miles southwest of Tucson, Arizona. In March 1959, mining from a moderate sized porphyry deposit known as the "Esperanza orebody" was begun at a rate of 10,000 tons of ore per day. Some five years later, a sizeable group of mineral claims west of Esperanza became available to Duval. Earlier exploration and development drilling in this area by others indicated an orebody of greater size but lower tenor than that of Esperanza. A drilling program conducted by Duval not only verified the results of the prior drilling but in addition, revealed a continuation of the mineralization to the south and east. Thus was developed the Sierrita orebody. Open pit design delineated 414 million tons of ore containing an average copper content of 0.35 percent and a molybdenum content of 0.036 percent. In April 1966, the office of Emergency Planning authorized General Services Administration to undertake a program under the Defense Production Act to en¬courage additional domestic production of copper in the interest of national defense. Duval's Sierrita Project was brought to GSA's attention in May 1966 on November 28, 1967, an agreement providing for the development of the Sierrita Property was consummated with GSA. In March 1970, the first copper-molybdenum concentrates were produced in the 72,000 tons-per-day concentrator. Pre-production stripping exceeded the scheduled 105 million tons despite the comparatively short lead time available to equip the mine, build the mine plant facilities, and staff the technical, supervisory, and labor forces. Shortly before the first concentrates were produced, plans were being formulated for a program to increase processing capacity by approximately 15 percent, which entailed increasing overall mining capacity by approximately 50,000 tons per day. This program is scheduled for completion early in 1971.

Jan 1, 1971

By M. Javier

This concept paper is presented in the hope of raising the awareness of mankind on the necessity for its peaceful coexistence with nature. It is a food for thought. It takes compromise and sacrifice of people, who will have to learn to curb their greed and move toward a more organic form of prosperity. A nature-friendly sustainability is first step toward the protection of nature that is critical to the mutual survival of mankind and nature. People need the resources from the finite earth to survive and nature needs the prevention of human destruction in order to continue to regenerate and provide. The contemporary notion of sustainability is self-serving. It serves the interest of industry by camouflaging itself to look like nature?s protector. The ?sustainability? concept presented in this paper aims to extend the longevity of the utilization of the limited natural resources for many generations to come. It is an important, responsible first step in creating a healthy sustainability concept that, when implemented, extends the longevity of mankind by the most efficient use of the finite resources on this limited Planet Earth, all the while taking into consideration the increase in anthropogenic activities due to exponential human population growth. This new definition of ?sustainability? has completely different characteristics than its contemporary versions. Nature has its own destiny, rules and principles. Being a part of nature, human society depends on it for survival and must play by its rules and never the other way round as in its initial pretensions. Society should not try to humanize nature, but rather to respect the rule of the nature in a peaceful way of co-existence. When implemented, this new concept of sustainability aims to affect the designs of engineered structures and revolutionize the recovery methods and processing of natural resources, such as mineral resources in the most efficient manner. Finally, this paper intends to stimulate critical thinking and initiate serious discussions aiming at producing a general consensus for the best definition for human society to not only enrich, but to extend its existence. Thus, the spirit of this new definition is pro future generations and environment. KEYWORDS: Sustainability Definition, Nature, Geomímic, Deproduction.

Feb 27, 2013

By Orris C. Herfindahl

Every few years we are treated to a battle over trade policy when the Reciprocal Trade Agreements Act comes up for consideration. In 1962 it is especially appropriate to consider the problem of mineral import -policy and the closely related problem of general import policy, for this year's struggle is different from those of the past in two ways. First, proposals have been made which are a substantial departure from past trade agreements legislation, and second, the formation and growth of the Europe Economic is Community may have an important bearing on the kind of legislation that is adopted. But this anticipates what is to come later. My task is to examine the problem of mineral import policy, although we shall find soon enough that general trade policy must be considered in order to get an indication of what is in store for minerals.

Jan 1, 1962

By Charles S. Robinson

INTRODUCTION Geology, the science of the earth, is the fundamental science in the construction of a tunnel. The approximate site of a tunnel is determined by its purpose. The geology of the tunnel site will determine the cost--or feasibility of a tunnel--the specific alignment to accomplish the purpose of the tunnel, the design of the tunnel (within the limits of the purpose of the tunnel), and the methods of construction. The more accurately the geology of a proposed tunnel can be depicted, the more accurately can the cost of a tunnel be estimated. The factors that should be defined for tunnel design and construction are the physical characteristics of the material in which the tunnel is to be constructed. The physical characteristics of the material are determined by the genesis of the material, and subsequent geologic processes that have affected the material. The geologic materials in which tunnels are constructed can be broadly classified as unconsolidated and consolidated. The unconsolidated materials include chiefly deposits of recent geologic time that occur near the surface. Because these deposits occur near the surface, and tunnels constructed in them will be at shallow depth, methods of physical exploration such as geophysical methods, trenching, and drilling will give more data at relatively low cost--therefore the physical exploration is generally, or should be, quite extensive--and the

Jan 1, 1997

By B. R. T. Simoneit

The formation of petroleum is normally thought of as a geologically lengthy process, involving the accumulation of organic matter, its gradual burial, diagenetic breakdown via geochemical reactions, maturation, heating within a 75-150'C "oil window" induced by normal geothermal gradients in the subsiding basin, and slow product migration into structural traps (Tissot and Welte, 1984, Hunt, 1979). The entire process can take millions of years and, indeed, most oil reservoirs probably formed in this manner. How-ever, today in sedimented, submarine rift basins (Fig. 1), Cl to >C40 hydrocarbons with the chemical and physical properties of crude oil are forming in demonstrably much shorter time by rapid thermal maturation of immature organic matter in hydrothermal regimes that are unusually high for sedimentary basins (Brault and Simoneit, 1988a, b; Didyk and Simoneit, 1988; Kawka and Simoneit, 1987; Peter et al., 1988; Simoneit, 1983; 1984; 1985a,b; 1988; Simoneit et al., 1984; 1987; 1988).

Jan 1, 1989

By Barton G. Stone

"Sampling is the process of taking a small portion of an article such that the consistency of the portion shall be representative of the whole," (Baxter and Parks, 1939)."An orebody is a mixture of minerals in proportions that vary in different parts of the mass. As a consequence, the proportion of contained metals also varies from place to place. Therefore, a single sample taken in any particular place would not contain the same proportion of metals as does the orebody as a whole except by a highly improbable coincidence."The probable error, which would be very large if only one sample were taken, decreases with the number of samples, but it never disappears completely unless the samples are so numerous and so large that their aggregate is equal to the orebody itself, in which case the orebody would be completely used up in the process of sampling."Since carrying sampling to such an extreme would defeat its own purpose, some probable error is always present in actual cases and the practical objective is to reduce this probable error to allowable limits. This means balancing the number of samples against the desired accuracy; if there are not enough samples the result is unreliable; if there are too many, the time and expense of taking them is excessive." (McKinstry, et al., 1948).In an actual orebody, the accuracy of sampling depends not only on the number of samples but also on their proper distribution throughout the orebody, for it would obviously be incorrect to take all of the samples either in a rich part or a lean part. Therefore, it is important to select the places in such a way that all parts of the orebody will be represented."

Jan 1, 2014

By R. D. Grove

The control of Florida phosphate flotation plants is largely based on the visual observations of experienced operators, both in recognizing good and bad froth conditions and in making judgments about the composition of feed, concentrate and tailing streams. Chemical analyses lag the process by at least two hours and therefore only assist in recalibrating the operators' vision when major deviations occur. An image analysis system has been developed by IMC Fertilizer to improve upon the accuracy and precision of the composition estimation process. It still relies upon the operator taking a representative sample, but provides a measurement in about 15 minutes after that sample is obtained. This paper describes the system and its use and presents comparative results for various process streams.

Jan 1, 1993

By J. R. Johanson

Many solids processes that look feasible on paper or even in pilot studies become disasters in full scale. Changes in solids flow characteristics from pilot scale to full scale because of larger so lids contact pressures, thermal shocks or unforeseen temperature excursions often cause full scale solids flow problems not encountered in the laboratory or pilot studies. Fortunately, proper applications of solids flow principals and solids flow property measurement at full scale conditions can anticipate the problems and thus provide an accurate basis for full scale design or existing plant modifications.

Jan 1, 1988

By G. J. Allen

Kennecott Copper Corporation's Nevada Mines Division initiated a program to stabilize the inactive portions of the tailings disposal area and perimeter dikes in 1946. To date, approximately 1,000 acres have been stabilized with vegetation and ground cover.

Jan 1, 1978

By Alain Broussaud, Guy Fourniguet, Jacques Franck, Pierre Conil

Steady-state simulation is now in current use to assist mineral processing plant design and optimization. However, the reliability of results generated by simulators has not until now been seriously investigated. A simulator supervision algorithm was designed and programmed to study both the influence of the reliability of experimental data on the accuracy of unit operation model calibration, and the influence of unit operation model accuracy on the results of direct plant simulations. An application to a grinding flotation plant is described and discussed. The approach may open the way to the quantitative analysis of the risks taken in mineral processing projects, which would be similar to the application of geostatistics to mining projects.

Jan 1, 1990

By Yuanyuan Wang, XUEWEN WANG, Jinzhi Wei, Ligang Wen, Muxin Jia, Zhengyao Li

The abstract discusses the use of disodium carboxymethyl trithiocarbonate (D8) as an effective depressant in the flotation separation of stibnite and pyrite. The study investigates the mechanism behind D8's selective inhibition of pyrite, utilizing techniques like micro-flotation experiments, contact angle measurements, infrared spectroscopy, adsorption capacity analysis, and zeta potential measurements. The findings reveal that D8 physically adsorbs onto both pyrite and stibnite, but its adsorption capacity on pyrite is significantly higher. This adsorption enhances the hydrophilicity of the pyrite surface, hindering the adsorption of the collector and effectively depressing pyrite flotation, while having minimal impact on stibnite floatability.

Mar 14, 2022