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By David A. Brence, Andrew D. Marti, Richard P. Stahura, Ronald J. Valentine

The development of an effective belt-cleaning system for a new conveyor system seemed a fairly conventional assignment. But a closer examination of the project showed a number of “fine print” details: •High altitude location (with resulting cold weather and low humidity conditions). •Long conveyor length. •Troublesome material (very sticky and capable of hardening like concrete). •Limited water. These difficulties are spelled out the challenge of developing a cleaning system for the production conveyor2 (PC2) belt at Climax Molybdenum’s Henderson Mine.

Jan 1, 2005

By Guangyao Si, Ismet Canbulat, Xun Luo, Yi Duan

Routine analyses of seismicity and event locations are essential for coal burst risk management, especially in the presence of unfavorable and complex geology. In an Australian longwall coal mine, a small-scale seismic monitoring network was installed to monitor a section of a major dyke intersected by the roadway, which was classified as a coal burst prone zone. The Deep Convolutional Neural Network (DCNN) technique was adopted for automatically discriminating seismic events to assess seismicity in this zone. The discriminated seismic events were located with the Shortest Path Method based on the Boundary Discretization Scheme (BDS-SPM) for temporal-spatial seismic event distribution analysis. The results demonstrate that the seismic events are discriminated with an average accuracy of 94%. Moreover, the seismic events are more accurately located using the BDS-SPM with a 3D heterogeneous velocity model compared with results obtained with a homogeneous velocity model. The temporal and spatial variances in seismic activities identify that the rock fractures in the dyke zone are closely related to the longwall mining process and a local dyke has a controlling influence on the stress concentration in its vicinity.

Apr 26, 2022

[Andrew Allen Glenwood Springs, Colorado C. S. Allen 211 Utah Oil Building, 10 West Broadway, Salt Lake City 1, Utah Earl W. Allen 257 Rio Grande Street, Salt Lake City, Utah Louis B. Allen 411 Walker Bank Building, Salt Lake City, Utah Thomas Allen State Coal Mine Inspector of Colorado, Argonaut Hotel, Denver, Colorado J. B. Ambler P. O. Box 591, Denver, Colorado Nephi W. Anderson Dragerton, Utah F. F. Argust 270 High Street, Pueblo, Colorado E. K. Arnston : 4601 West 26th Avenue, Denver 12, Colorado Abel Audin Somerset, Colorado Clement Audin, Jr Paonia, Colorado Ralph Andin P. 0. Box 285, Somerset, Colorado ]

Jan 1, 1955

By Jiann-Yang Hwang

A study on microwave assisted chalcocite leaching was carried out with a microwave hydrothermal reactor. The leaching was conducted with thick mineral slurries (50-100 g/l). The leaching media is a mixed solution of CuCL2 and NaCL The investigation included the effect of leaching temperature, quantities of the minerals per unit slurry volume as well as the initial concentration of cupric ions were investigated. The results were discussed and compared with that using conventional leaching method.

Jan 1, 2003

By Jorge Loredo, Jesús Garía Iglesias

"Abstract - The Asturian fluorspar district consists of vein and stratiform deposits where mineralization is controlled by a combination of lithological and tectonic factors.It is postulated that these fluorspar deposits have been formed under disequilibrium conditions created during circulation of ascending hydrothermal solutions along faults and other high permeability conduits. Mixing of solutions is inferred from fluid inclusion studies. Cavity filing and replacement processes are very important in localizing the ore deposits and in determining their morphology.Permian volcanic rocks in the area yield a regional positive geochemical anomaly in fluorine implying that Permian vulcanism may be a possible primary source of fluorine.On a regional scale a relationship can be established between some of the ore deposits and important tectonic lineaments. The stratiform deposits preferentially occur within a calcareous-detrital facies located at the margins of basins. These basin margins are related to important synsedimentaryfaults.Fluorite is the only economic mineral in these deposits. Quartz, carbonates, barite and pyrite are comnmon minerals accompanying fluorite. Other minerals that may occasionally be present as minor components are: marcasite, chalcopyrite, fahlore, sphalerite, galena and related supergene minerals."

Jan 1, 1994

By George F. Becker

A Nere record of Emmons's professional career would very inadequately represent the man. That he was eminent mc know, and our successors will realize in due time; but they must depend upon us for knowledge of a singularly ~vholesome, modest, unselfish personality, and of a character that did honor to a profession in which trustworthiness is indispensable. Those members of the Institute who met Emmons are his friends, and I never knew .one of these who was not the better for that friendship. Emmons was born in Boston, Mar. 29, 1841, the son of Xathaniel H. and Elizabeth (Wales) Emmons, and was named Samuel Frankliri after an ancestor who was of the sarne family as Benjamin Franklin. He took the degrcc of Bachelor of Arts at Harvard in 1861, and soon afterwards went abroad to complete his education. From 1862 to 1864 he attended the courses at the fieole Impkriale des Mines at Paris, Elie de Beaumont arid Daubrke being among his professors. The year 1864-1865 he spent at Freiberg under Cotta and other famous teachers; after which he spent another year in traveling through Europe. Like many other renowned geologists, he approached his ultimate profession from its economic side, and was thus from the first imbued with a sense of high responsibility in the promulgation of scientific opinions or conclusions. With hypotheses which were interesting merely because they were ingenious or even plausible, he would have nothing to do. In 1867 he joined the Geological Exploration of the Fortieth Parallel at its organization under Clarence King, serving at first as a volunteer, but soon receiving a regular appointment. This expedition was the first one of purely geological character sent out by the United States government. As Emmons has shown in his admirable presidential address on " The Geology of Government Explorations," its work was founded on a com-

Jan 1, 1912

This report describes the redesign, development and field demonstration of a remote shotcrete lining system, capable of operating in shafts and mines from 8 to 16 feet in diameter at depths up to 1000 feet. The original contractural scope of work outlining problems and remedial measures associated with a previous unit proved inadequate. Significant additional effort was necessary in order to fulfill the project objectives of producing a functionally reliable remote shotcrete lining system. Included with the engineering and technical description of the system, is a comprehensive technology package. Included with this material is ancillary equipment, materials selection procedures, mix-design data, quality control and assurance program, selection and training of personnel and the organizational aspects required to operate the entire system. The report concludes with details of a successfully completed borehole lining operation at the Nevada Test Site. An irregular 104 inch diameter borehole was lined at a rate of 4.8 feet per hour and 20 feet per hour respectively for 8-9 inch and a 2 to 3 inch shotcrete thickness.

Jan 1, 1983

By E. J. Owen, S. Cherotich, V. T. McLemore

Breccia pipes are vertical pipe-like columns of rocks that provide conduits for fluid flow and open spaces for mineral precipitation, hence are focus areas for exploration. In the Gallinas Mountains, Lincoln County, New Mexico, there is recorded production of Cu, Pb, Ag, F, Fe, REE (as bastnäsite), and Au from 1902 to 1980, but no production reported from the breccia pipes. Previous studies described the occurrence of REE in breccia pipes, but their transportation and deposition controls are still unclear. The aim of this research is to characterize the magmatic-hydrothermal breccia pipes in order to understand the geochemical and physical conditions of deposition of REE and gold in the breccia pipes found in the Gallinas Mountains. There are more than 20 exposed breccia pipes that form a NE-trending belt about 3–5 kilometers, mostly gray-brown and consist of angular- to sub-rounded rock fragments, some host high concentrations of REE (80,500 ppm total REE) and Au (175 ppb). Preliminary studies suggest they are magmatic and intruded into the host rock and, subsequently, hydrothermal fluids precipitated F-REE and Au along the edges of some breccia pipes. More studies are underway to test this hypothesis.

Feb 1, 2023

By W. E. Coughlin, R. L. Faverty, F. H. Lightner

Introduction The intent of this paper is to present the general strategy and method of implementation to achieve a "fast-track" mine development. The major objectives of a "fast-track" or rapid development schedule are to minimize front-end development expenditures and to realize an early cash flow from operations. The Borealis project of Houston International Minerals Corp. (HIMCO) is used as the working example to illustrate the development schedule. Borealis is a 2.3 kt/d (2,500 stpd) gold-silver heap leach operation near Hawthorne, NV, Pre-Feasibility Planning Proper early planning and identification of priority items were necessary to expedite project progress. On April 1, 1978, HIMCO leased the rights to the Borealis prospect and initiated exploration activities almost immediately. Since Borealis was showing excellent potential for mine development, an effort to clear the way environmentally was initiated during the summer of 1979. With the Borealis properties located within the Toiyabe National Forest, the US Forest Service (USFS) was recognized as the "lead" or respon¬sible agency for addressing the environmental issues. Early scoping of the environmental issues by both HIMCO and the USFS allowed HIMCO to take the initiative and address two potentially critical issues-archaeological and biological. Third party consultants, agreed upon by HIMCO and the USFS, were contracted to conduct archaeological and biological surveys. Desert Research Institute of Reno, NV, provided archaeological services, and JFL & Associates of Boulder, CO, provided biological services. These efforts began in the fall of 1979 and continued through the summer of 1980. Conservative Design Criteria By adoption of conservation design criteria, flowsheets and processing data required for detail engineering were firmly established with a minimum of impact on schedule. On Oct. 21, 1980, HIMCO formally initiated a feasibility study to evaluate the Borealis project. Four organizations were contracted for particular scopes of work: • John T. Boyd Co.: Ore reserve estimation, preliminary mine plan, and mine capital and operating cost estimation. • Bechtel Civil and Minerals: Conceptual engineering, processing capital and operating cost estimation. • Hazen Research Inc.: Metallurgical testing. • Sierra Pacific Power: Cost estimation for power supply. Metallurgical testing and conceptual engineering of both heap and agitation leach flowsheets were investigated concurrently. Numerous economic evaluations were conducted for both heap and agitation leaching at varying production capacities. The results indicated a heap leaching flowsheet treating 454 kt/y (500,000 stpy) yielded the best economics and was compatible with the "fast-track" development goal. Conservative design criteria was established to provide operating flexibility and ensure plant productivities. A summary of major design criteria is presented in Table 1. HIMCO assembled the results of the studies of the various consultants along with internally generated studies to produce the feasibility document. The decision to supply 100% equity by HIMCO rather than arrange project financing help to expedite the project. Cooperation Between HIMCO and Regulatory Agencies With cooperation and mutual trust established between HIMCO and regulatory agencies, the time required for environmental permitting was streamlined as much as practical. To expedite the required construction permits, HIMCO proposed to the USFS that HIMCO fund the total cost of an Environmental Assessment Report (EAR) and that issues be addressed at the technical level of an Environmental Impact Statement (EIS). The previous studies on the critical issues of archaeology and biology provided HIMCO with the information to satisfy the proposed approach. Houston International Minerals and the USFS agreed to have Environmental Research and Technology (ERT) of Fort Collins, CO, prepare a draft EAR for the USFS.

Jan 11, 1983

By S A. M Crawshaw, J A. B Fortune

Trackless battery powered haulage vehicles have been in operation in British coal mines principally for longwall face transfer and personnel transportation. Changes within the industry have resulted in the introduction of room and pillar coal mining methods and the introduction of increasingly heavier longwall roof supports This has resulted in the introduction of: • Battery powered coal haulage machines, which, without the need for trailing cables, increase productivity within room and pillar mining. • Battery powered longwall shield haulers which are capable of carry ing the heaviest shield supports currently being utilised within the British coal mining industry. The conventional machines have been adapted from an American design to meet the requirem ents of European legalisation. This has seen the- emphasis being placed upon the supplier with the European M achinery Directive being introduced, necessitating the assigning of a 'C E ' m ark to each vehicle. Battery vehicle technology has advanced to meet the demands of the ever changing market and will no doubt he further adapted to meet the requirement of the British coal mining industry.

Jan 10, 1996

By H. Dolezal

An investigation was made on the use of magnesium for the direct reduction of rutile to make low-cost, offgrade titanium which could be upgraded to an acceptable grade of metal by electrorefining. Reductions made with charges containing magnesium chloride under hydrogen yielded products with oxygen con-tests close to the theoretical equilibrium composition. Two reduction products were made from rutile for use in electrorefining amenability tests: (1) a product from reduction in an inert atmosphere which contained 88.9 percent titanium and 4.42 percent oxygen, and (2) a product from reduction in a hydro-gen atmosphere which contained 92.5 percent titanium and 2.40 percent oxygen. Reduction products obtained under both of these conditions were amenable to electrorefining.

Jan 1, 1965

By I Sucholutsky, D M. First, D Mogilny, F Yusufali

Machine learning is creating value in all facets of the mining industry, from exploration to production. The authors provide an accessible, high-level introduction to artificial intelligence (AI), machine learning (ML), and deep learning (DL); the latter being widely recognised as one of the most powerful forms of ML. In particular, the authors will introduce deep learning models known as convolutional neural networks (CNNs), how they are applied, and the economic considerations necessary for determining when DL may be the right solution to de-risking complex block modelling problems. The authors present preliminary results from the mineral resource modelling study of the Jundee orogenic gold deposit, Yandal belt/gold province, Western Australia. The primary goal was to identify the direction and location of the narrow gold veins more accurately and demonstrate how non-linearly correlated elements are used as direct inputs to the resource model to assist with the target element’s grade prediction. This demonstrates that: (1) existing techniques for finding correlations between assayed elements do not adequately reflect the complex geology of the asset, (2) nonlinear correlations that are difficult to model as simple mathematical functions are representative of geological patterns in a deposit, and (3) non-linearly correlated assayed data, fed as inputs, increase the performance of the resource model as reconciled through blind tests. To conclude, the authors hypothesise that the patterns represented by the DL block models may be revealing the results of overprinting geological processes that generated mineral deposits. For example, the primary hydrothermal processes that deposited metals created depositional patterns that become particularly complex as a result of being overprinted, in part or in whole, by secondary physicochemical processes. This may explain why non-linear geochemical relationships have the capacity to generate more accurate block models of mineral deposits.

May 24, 2023

By RavikiranVaidya, Vishal Dhamecha

Low Strain Pile Integrity Testing has been used in India since 1990’s and several have tried to demonstrate the utility and benefits of this method. However, use of this technology was limited till 1998 as not enough data maybe was not available to justify its use and application on major infrastructure and real estate projects. The first author has done significant work in this method resulting in its use in practically all sectors of the industry that use concrete bored pile foundations as a supporting element. The paper explains various signal enhancers or modifiers involved in processing of low strain test data and its implication on the final output. It also describes how the method can lead to abuse or can provide poor interpretation if incorrectly used. The current effort is to demonstrate that data collection and evaluation becomes complex with changes in soil stratum and pile profile. The paper highlights the present testing practices and provides a guideline for classification of pile integrity into few simple categories in Indian context rather than writing complex interpretations.

Sep 1, 2022

By Xiyu Gao, Yi Yang, Mark I. Pownceby, Shuiping Zhong, Miao Chen

In the present study, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray absorption near edge structure (XANES) spectroscopy, and Raman spectroscopy were used to investigate the effect of chloride ions on chalcopyrite bioleaching and chemical leaching at 25 °C. The leaching results show that the addition of chloride ions suppressed the dissolution of chalcopyrite in both chemical and bacterial leaching. In chemical leaching, the solution redox potential in the experiment without Cl− stayed in a range more suitable for chalcopyrite dissolution compared with experiments with Cl− . In bioleaching, the bacteria activity was suppressed by Cl− leading to low dissolution rates of Cu. Surface morphology and chemical speciation studies confirmed the formation of potassium jarosite on the surface of the chalcopyrite leach residues. In addition, S K-edge XANES indicated the formation of trace amount of elemental sulfur and covellite on the mineral surfaces.

The following is an incomplete list of members and guests who called at Institute headquarters during the period Jan. 10, 1918 to Feb. 10, 1919. Walter F. E. Barcus. Lt. C. K. McDonald, U. S. N. R. F. Capt. D. H. Bradley, Jr. Major John DeN. Macomb, Bayhead, N. J. Melvis Buigger. - Samuel Melitzer, New York City. Eugene Coste, Calgary, Can. T. C. Merriman, New Haven, Conn. C. W. Cromwell, Warren, Ariz. Wm. J. Millard, Tulsa, Okla. E. O. Daue. Benj. L. Miller, Bethlehem, Pa. Capt. H. W. Edmondson. S. B. Patterson, Jr., Allentown, Pa. E. W. Engelmann, Hayden, Ariz. Lynn L. Pomeroy, New York City. C. Mason Farnham. W. E. Pomeroy, New York City. Lt. C. W. Frith, Salt Lake City, Utah. G. M. Ponton, Ottawa, Ont. John T. Fuller, Honesdale, Pa. Wallace E. Pratt, Ft. Worth, Tex. Walter A. Funk, Idaho Sp., Colo. Harold L. Rau, Milwaukee, Wis. Major W. R. Grunow, New York, N..Y. Lt. E. J. Ristedt, Camp Merritt. A. W. Hackwood, Butte, Mont. George M. Ryall, Los Angeles, Cal. Lt. Nathaniel Herz, New Haven, Conn. D. B. Scott, Mogollon, N. M. Ralph T. Hirsh, New York City., W. H. Staver. O. P. Hood, Washington, D. C. Douglas B. Sterrett, Washington, D. C. E. B. Hopkins, Houston, Tex. J. A. Stewart, Minneapolis, Minn. Hugh C. Ingle, Pensacola, Fla. R. H. Summer, Wilmington, Del. Capt. Wm. F. Jahn. W. G. Swart, Duluth, Minn. Roswell H. -Johnson, Pittsburgh, Pa. Kirby Thomas, New York City. Jesse L. Jones, Pittsburgh. Pa. Capt. H. D. Trounce, San Diego, Cal. Edgar Kidwell, Berkeley, Cal. L. Unger, New York City. .D. H. Ladd, Detroit, Mich. George F. Vivian, Butte, Mont. Raymond B. Ladoo, Cambridge, Mass. R. A. Walter, Reading, Pa. W. H. Landers. Lt. R. G. Wayland, Chehalis, Wash. David Lasner, Elizabeth, N. J. R. J. White, Wallace, Idaho. J. M. Lilligren. J. S. Wroth, Albuquerque, N. M. Lt. Wm. J. Linn, Chicago, Ill. Herbert Hoover, General Pershing, Ambassador William G. Sharp and Admiral William S. Benson were speakers to-day at the annual luncheon in honor of Washington's Birthday, given by the American Club of Paris at the Palais D'Orsay.

Jan 3, 1919

Flinders Power, formerly NRG Flinders, is considering the possible use of low rank coal from Lake Phillipson, South Australia (SA) in its power stations at Port Augusta, SA. Typically, this coal contains about 35% moisture and 10% ash. Unfortunately, it also contains high levels of sodium (1% Na) and chloride (0.95% Cl) with a Na2O level in ash of 18.9%. Such levels cause serious problems during coal combustion, making the use of as-mined coal impractical for power generation. This paper describes the development of an aqueous leaching technique to remove 90% of the sodium and chloride and to yield a product with a Na2 O level in ash of less than 3%. Small-scale agitation leaching tests with good quality tap water at ambient temperatures showed that the coal needed to be crushed to minus 5.6 mm to obtain maximum removal of water-soluble sodium and chloride in 30 min. Leaching kinetics, but not the ultimate removal of salt, were enhanced by the use of higher temperatures (up to 150°C), but this was deemed uneconomic. Varying the pulp density between 20% and 50% had little effect on extractions and there was no benefit in multiple stage water washing. The best results by water leaching were 69%~74% extraction for sodium and 95%~97% for chloride, meaning that the sodium removal was well below the target level. From SEM examinations of the leached product it was concluded that the remaining sodium was organically bound to the carbon atoms in the coal. Further tests using aqueous solutions containing cation exchange additives such as calcium chloride (CaCl2) or ammonium chloride (NH4Cl) or sulphuric acid (H2SO4) showed that significantly enhanced sodium extractions were possible and target specifications were met. Two options, namely a single-stage and a two-stage leach, were then investigated. In a single-stage leach with additive, minus 5.6 mm coal was leached at 33%~50% solids for 30 min at ambient temperature and then filtered and washed with fresh water. This gave a sodium removal level of about 81% and a Na2O level in ash of about 5%. These levels do not quite meet tar-get specifications. In a two-stage leach, the coal was first leached with water alone without an additive as in the single stage leach, and the washed residue re-leached under similar conditions for about 5 min with an additive (CaCl2), and then filtered and washed. This gave a cumulative sodium removal of 96% and a Na2O level in ash of 1.4%~2.4%. These levels are well within target specifications.

Jan 1, 2014

By Raymond K. Will

Computers are becoming increasingly valuable tools in the mining industry as a greater variety of appropriate hardware and software becomes available, combined with greater acceptance by management, Within a given time period an engineering staff can evaluate or design a project to much greater detail and higher accuracy by utilizing computers once suitable programs have been developed. We are all aware that throughout the world the decreasing grade of minerals coupled with increasing waste to ore ratios necessitate larger capacity, longer term mining operations and attendant higher capital costs. Computers can be of assistance in all stages of mineral exploitation, from geologic exploration through mine feasibility studies and design, to marketing and transportation. Because of the high speed with which data can be digested and manipulated by computers, preliminary information from any stage of investigation can be analyzed to assist in further guidance of that stage. By use of preliminary mine feasibility studies, financial forecasts and sensitivity analysis, even information from a far-removed phase such as marine transportation of the product, can help guide the exploration phase to a realistic target.

Jan 1, 1973

By Pamela Paradis-Sokoloski, Deni Thibodeau, J. Denis, Samantha J. Espley, P. O’Donnell

"During the previous decade, the role of spray-on liners within the mining industry was limited to providing a corrosion resistant coating to screen and bolts; however, increasingly, liners are being used as ground support products. Expanding use and testing of liners have demonstrated their ground support function, yet the definitive support mechanism is still under debate. The most promising theory is the retain/hold/reinforcement concept (Kaiser et al.,1992). This conceptual theory has been the basis for the recent underground trials at INCO where, specifically, shotcrete and MIROC Mineguard were tested in two trials to further define limitations and applications of each liner.In a cursory overview, shotcrete is becoming accepted as a support product, while Mineguard is only slowly gaining acceptance.This discrepancy is the result of the corresponding life-spans within the industry, whereby shotcrete has had wide-spread use for decades, yet Mineguard has only recently been introduced. Currently at INCO, shotcrete is primarily used: to provide support in poor ground conditions, to add stability when developing through backfill, and to provide damage control in seismically active mines. It is also used to protect production headings and secondary-blasting chambers from fly-rock damage during blasting. Despite an obvious support function of the liner, shotcrete has always been used in addition to bolts and screen. Comparatively, Mineguard is still in the testing stage, where the greatest potential is increased productivity for applications in multi-tasking development headings. In this scenario, Mineguard provides instant support to replace screen, and bolts temporarily. When the heading has advanced, the drill and support crews work in tandem, drilling off the next round and installing bolts for long-term radial support, respectively. Other potential applications of Mineguard are within production headings to replace screen in the back, and screen and bolts in walls. The potential for both liners to replace conventional support is clearly war-ranted, such that defining the support role was the primary goal of the two underground trials."

Jan 1, 1996

By I. Gaballah

Cadmium is toxic to plant, animals and humans. The council directive of the European Communities No 8315 13lEEC has fixed an upper limit of 200 ppb for the release of cadmium in industrial effluents. The conventional method of neutralization/prccipitation ( NIP ) is inefficient to reach this limit. The objective of this study is to test the efficiency of the trees modified bark to remove cadmium cations from industrial effluents after the conventional treatment by NIP. Laboratory scale tests with synthetic solutions show that the cadmium removal depends upon pH and initial concentration. About 99.9 %, 99 % and 96 % of the metal are removed from synthetic solutions containing 10, 100 and 1000 ppm respectively. Pilot plant trials ( 1 m3 ) with an industrial effluent bearing about 500 ppb of cadmium lead to the almost complete elimination of the cadmium ( final concentration is lower than the analytical detection limits < 20 ppb ).

Jan 1, 1994

By Morrison AL

The volume changes occurring during the reduction by hydrogen of single, high-grade hematite pellets under isothermal and non- isothermal conditions were investigated using a time-lapse photographic technique. The major cause of swelling during iso- thermal reduction at temperatures in the range 600-1000¦C, was the disruptive stresses set up during the transformation of hematite to mag- netite. The severity of the disruption was temperature dependent; the degree of swelling increased with increases in the reduction temp erature. Under non-isothermal reduction conditions, in which the pellet temperatures were increased at constant heating rates over the temperature range 500-1000¦C, minor swelling (6-8%) occurred in the initial stages of reduction followed by pellet contractions of up to 15% in the final reduction stages. The low initial swelling and high final pellet shrinkages were due to a com- bination of the temperature dependence of the swelling mechanism, and the sintering of fine pores in the reduced iron in the latter stages of reduction at higher temperatures.

Jan 1, 1980