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By H. Kenworthy

Sulfide-ore concentrates containing cobalt, nickel, copper, lead, and iron from the operations of the National Lead Co. at. Fredericktown, Mo., were treated successfully on a laboratory scale to recover more than 90 percent of the cobalt, nickel, and copper. A cobalt -nickel-bearing, lead-copper matte., produced by the St. Joseph Lead Co. at Herculaneum, Mo., was treated to produce a lead-zinc fume, a copper sulfide concentrate, and a cobalt nickel-iron product, netting a recovery of over 75 percent of the cobalt and about 90 percent of the nickel and copper. National Lead Co. bulk concentrates were chlorinated with gaseous chlorine to form anhydrous metal chlorides and sulfur chlorides, sulfur chlorides were recovered by distillation, a high percentage of the ferric chloride was converted to ferric oxide, and the chlorinated residual metals were extracted with water. Metal ions were removed from leach liquors by pH-controlled fractional precipitation as hydroxides. Cobalt solutions "were prepared from cobaltic hydroxide, and procedures were developed to remove contaminating metal ions. Purified cobalt solutions were employed as electrolytes for deposition of high-purity cobalt.

Jan 1, 1953

By August E. Vandale

I speak to you today on the subject assigned to me, "Subsidence - a Real or Imaginary Problem", as a representative of Consolidation Coal Company (a wholly owned subsidiary of Continental Oil Company). The information I relate to you is our experience in the Pittsburgh Coal Company Division of Consol and covers the Pennsylvania properties and mines with particular emphasis on the mines in the south- western portion of the State or in the immediate vicinity of Pittsburgh, Pa. Mining of Freeport and Pittsburgh seams of coal in the Pittsburgh vicinity dates back over one hundred years. Consol, or its predecessor, Pittsburgh Coal Company, has been actively engaged in mining in the area since Pittsburgh Coal Company was organized in 1900. Pittsburgh, Pennsylvania came into prominence as the Steel City largely because of the vast reserves of high grade metallurgical coal readily available in the immediate vicinity and also because of its favorable river transportation. Early in the 1900's we operated over 100 small coal mines, with operations located in the Counties of Allegheny, Fayette, Washington, Westmoreland. We have also operated mines in Somerset and Greene Counties. Titles in Pennsylvania can be in three estates: (1) title in fee, (2) title to the mineral, (3) mining rights permitting the removal and extraction of the mineral with or without waiver of surface damage. Consol has over the years acquired good legal title to the coal lands purchased from individual farm owners, with good broad mining rights, and in 98% or more of its title has a complete waiver of surface damage or the right to subside the surface land. In the early days of our Company, individual coal farms were purchased from land owners. Many of these titles severed the coal estate from the in fee title and good mining rights with waiver of surface were conveyed in the original severance deed. Thus, minable coal reserves were put together by the purchase of the coal under many individual farms in an area. In the early years, the mines practiced hand dug mining - later going to mechanical cutting with hand loading of the coal. Systems used were entry driving with room and rib panels. We have practiced full recovery mining as far as practical during the years of hand loading, as well as in the later years when the mines were mechanized. Mining system layouts, methods and procedures have changed from time to time to keep pace with improved mining machinery and new inovations, such as roof bolting and rubber tired haulage.

Jan 1, 1967

By Jayne Somers

Methane (CH4) is a potent greenhouse gas, accounting for 15 percent of all global greenhouse gas emissions in 2005. Since methane has a much shorter atmospheric lifetime than carbon dioxide (CO2), reducing methane emissions can achieve considerable climate benefits over the next 25 years. Coal seams often contain significant quantities of methane and CH4 released to the atmosphere from gassy mines during coal extraction is a major source of greenhouse gas emissions. Methane (CH4) emissions from coal mining activities constitute approximately 6% of total global human-related methane emissions. Coal mines around the world have recognized that methane is a clean energy resource that can be captured and used productively. Coal mine methane (CMM) is currently utilized for power generation, natural gas pipeline injection, vehicle fuel, industrial process feed stocks, on-site mine boilers, mine heating, and home heating distribution systems. Upgrading mine degasification systems can often improve gas quality and create favorable project economics. The United States has been a leader in coal mine methane (CMM) recovery and use since the 1990?s. There are now 15 projects at active underground mines in the U.S., as well as 26 abandoned mine methane projects. Recovery and use projects at active underground U.S. mines reduced methane emissions by approximately 49 Billion cubic feet in 2010. In an exciting new development, a ventilation air methane (VAM) mitigation project at the CONSOL McElroy mine in West Virginia was installed by Verdeo. Operational since September 2012, this is the first commercial-scale VAM project in the U.S. and the project will reduce methane emissions by an estimated 920 MMCF/yr. As part of the U.S. Greenhouse Gas Reporting Program, actual data on methane emissions from underground coal mines was collected for the first time in 2011 and reported to U.S. EPA in September 2012. The data collected will help inform stakeholders, particularly the underground coal mining industry, of CMM emission sources on public and private lands. The detailed data will also shed light on the specific sources of methane from active underground coal mines and highlight project opportunities for the U.S. coal industry. The paper will cover U.S. coal mine methane emissions, U.S. CMM utilization and destruction projects, Federal policies and State incentives for CMM capture and utilization. 2011 CMM data from the U.S. Greenhouse Gas Reporting Program Subpart FF will be analyzed and compared with previous U.S. Greenhouse Gas Inventory estimates. Other developments, including the voluntary carbon market, will be discussed.

Aug 1, 2013

By Felipe De Lucio Pezet

El presente texto es un recuento de acontecimientos importantes ocurridos en el distrito minero de Morococha desde la época precolombina hasta 1940, de forma que contribuya al desarrollo de la historia minera del Perú.

Nov 1, 1979

By Joseph Kennedy

How do terrorists and other criminal bombers acquire explosives to be used in an attack against U.S property and/or citizens? The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) with nearly 40 years of investigating bombings and other explosives incidents, has learned that explosive materials intended to be used in criminal acts are obtained primarily by theft, clandestine manufacture or diversion.

Jan 1, 2010

By Weijie Wei, Jinwang Zhang, Jiachen Wang, Yang Li

"Longwall top-coal caving (LTCC) mining technique is one of the important methods for underground thick seam extraction in China. The coal seam in LTCC panel is divided into two parts: bottom-coal and top-coal. The bottom-coal is mined by conventional longwall method while the top-coal is mined by caving method. The top-coal caving process in LTCC and block caving process in metal mine are both gravity flow of loose ore/coal blocks. However, the presence of caving shield in LTCC makes the characteristics of drawing body shape in the two caving processes differ a lot. This paper discusses the influence of caving shields on the characteristics of drawing body shapes in light of recent studies of the top-coal drawing process. The theoretical model for describing the drawing body shape in LTCC is proposed both along the seam strike and seam inclination. Then, the experimental data are used to validate the correctness of the theoretical model. Furthermore, two examples of how the theoretical findings assist LTCC mining are given and discussed.INTRODUCTIONLongwall top-coal caving (LTCC) mining technique and large-cutting-height mining technique have been widely used for extracting thick coal seams in China. About 0.6–0.7 billion metric tons of coal come from longwall top-coal caving panels every year. The maximum annual production is 15 million metric tons per panel _The mining method employed in such panel is a combination of top-coal caving mining technique and large-cutting-height mining technique, which is suitable for seam height between 12–20 m, as shown in Figure 1. Apart from China, LTCC has also been employed in some coal mines in Australia and Vietnam (Le et al., 2017).The coal seam in a LTCC panel is divided into two parts: bottom coal and top coal. The bottom-coal is mined by the conventional longwall method, while the top coal is mined by the caving method. The top-coal caving process in LTCC and block caving process in metal mines are both gravity flows of loose coal/ore blocks, as shown in Figure 2. However, the presence of caving shields in LTCC causes the characteristics of the drawing body shapes in the two caving processes to differ significantly.There are two main differences between the blocking method and the top-coal caving method:"

Jan 1, 2019

By M Edhammer

In 2007, Atlas Copco introduced an integrated tunnel scanner/profiler. The tunnel scanner, which is integrated into the control system, is mounted on the drill rigs, and replaces the previous variants of non-integrated scanner equipment. The Atlas Copco Tunnel Profiler, which is the name of this system, is currently being used by several contractors and mines on various projects in Scandinavia, Finland and Australia. Atlas Copco Tunnel Profiler can scan a tunnel of 65 m2 in just five minutes and is integrated with the computerised control system for the drill rig. This integration means that the results of scanning are immediately available for analysis on the computer screen both in the drill rig and in Tunnel Manager; a software for tunnel and drift planning.In 2008, a method was introduced for locating the drill rig with a total station navigation (TSN) system, integrated into the control system. TSN systems are used by a number of contractors in Scandinavia and Finland, as well as elsewhere in the world. Using a TSN for navigation is in itself not new, but when this is integrated with the control system it provides the opportunity for individual drill rig operators to use this method, without the direct assistance of a surveyor. TSN gives a very precise indication of the drill rig’s position in relation to the tunnel design. An accuracy of ±1 cm compared with the ±10 cm which is normally obtained with the traditional method using tunnel laser and sight plates on the drill rig’s feeder. The closer a tunnel is blasted to its planned profile, potentially the more is saved in terms of less shotcreting, extra rock bolting and other corrective work. A better quality tunnel is the key to better overall economy and today’s technology makes it possible to achieve that goal in every type of tunnelling and mining project.In addition to total station’s ­navigation and Tunnel Profiler, the concept of ‘high precision tunnelling’ also includes:•Software tunnel planning: Tunnel Manager, Tunnel Manager Pro and Tunnel Manager Measure while drilling.•Measurement While Drilling (MWD)collects the various drilling data and the interpretation of these for the early identification of variations in the rock.•Rig Remote Access (RRA) is a support for wireless or wired communication between drill rig and planning office. The result is being able to send planning data to the drill rig and to simultaneously have the facility for logged files to be sent from the rig to the office. There is an option of an external computer logging in to the drill rig’s control system to view menu screens and settings, and remotely troubleshoot and plan appropriate action.

Mar 21, 2011

By Bartho J. Admiraal, Antoine Feddema

Pneumatic sinking of caissons has been established from mid-19th century. The technique of pneumatic sinking has been applied on many projects for underground construction up to depths over 20m below groundwater level since that time. Volker Staal en Funderingen, a known deep foundation contractor in the Netherlands, was awarded two contracts in 2015 for sinking in total 2 caissons in Hamburg (Germany) to large depths (over 30 m (100 ft) and two projects near Amsterdam (the Netherlands). The latter concerned two gate chambers for the world’s largest sea-lock, one of them was 55x81 m2 (180x266 ft) to a depth of 25.5 m (84 ft), which would mean a world record for pneumatic sinking! But with depths and dimensions like these, the deployment of personnel is the main limiting factor for production, despite all developments to date. It was decided to develop a remote controlled process, including the necessary equipment and monitoring systems. Monitoring not only the kinematics of the equipment in the working chamber and the production parameters related to the excavation but also of the structural behaviour of the sea-lock gate chambers was essential for approval of this innovative execution method. The lay-out and the sizes of the largest caisson the structural integrity was extremely critical for torsion and bending moments. A displacement controlled execution by the observational method was therefore required. In engineering a new approach for modelling the semi-continuous failure mechanisms of the soil was needed to understand the sensitivity of the excavation process and to define limit values for the execution. In the paper these structural and geotechnical issues will be explained together with the experiences during the execution.

May 1, 2022

By Uday B. Pal

In the electrochemical vapor deposition (EVD) process, gaseous cation precursors are passed over one side of a porous substrate, and oxygen is passed on the other side of the substrate. The gases diffuse and react within the porous substrate, and the pores get filled with the desired solid oxide. Subsequent solid state electrochemical transport through the solid oxide in the pores continues the reaction, and the film grows over the porous substrate. The EVD process has been used to deposit lanthanum chromite interconnection films and yttria stabilized zirconia electrolyte films over porous air electrodes. The EVD growth of these solid oxide films is found to be parabolic in nature, which indicates that the solid state transport (diffusion) of ions through the film controls the growth. This solid state transport can be analyzed using Wagner's treatment of the electrochemical transport. Conductivity measurements and the information on the defect structure of the oxide can be combined with the EVD growth rate measurements to calculate the solid state transport properties (transport numbers and partial conductivities) of the rate-controlling minority species in the oxide. Using this approach, the EVD growth of other electronic, mixed conducting and ionic solid oxide films can also be analyzed.

Jan 1, 1992

By Michael Perlow

Helical screw piles in use since 1838 are routinely used for energy, transportation, municipal, industrial, marine and coastal infrastructure as well as for excavation support, environmental remediation, and foundation repair. They are especially well suited for work in constrained areas, renovations and structure retrofits. Helical pile design procedures over the past 10 years have gone through a remarkable evolution with the establishment of the 2007 AC358 Helical Pile Acceptance Criteria and inclusion of helical screw piles in the 2009 International Building Code (IBC). New 2009 IBC building code requirements and AC358 Acceptance Criteria are presented along with advances in helical pile design procedures, installation, QA/QC, and recommended load test verification criteria. Use of helical smart piles to validate helical pile design and verification of ultimate pile capacity is highlighted.

Jan 1, 2011

By S. R. Wilson

[The Anniversary-Bucky pegmatite is one of the largest, dikes in the Quartz Creek district, 21 miles east of Gunnison, Colo. The major dike consists of quartz-albite pear pagmatite and graphic granite with many quartz masses as individual cores occurring within the dike. A mining operation on one of the largest core areas has exposed several mineralogic cones directly associate with the core. These zones, including the large- units of the dike, are quartz pegmatitc, quartz-perthite pegmatite, perthite pegmatite, muscovite-feldspar -quartz pegmatite, quartz-albite pegmatite, and perthite-quartz (graphic granite) pegmatite. Muscovite and beryl are found in the muscovite-feldspar-quartz zone and are the only two products that have been marketed. Other potential products are perthite, graphic granite, and possibly small quantities of columbite-tantalite, monazite, and related radioactive minerals. The Bureau of Mines drilled two diamond-drill holes during April 1950 to investigate the largest and cost promising core area. This, report describes the results of this drilling.]

Jan 1, 1953

By Q. H. Liao, B. G. Monaghan

The options for designing slopes in complex geological conditions are reviewed. It is shown that modelling, especially numerical modelling, allows a degree of analysis that cannot otherwise be achieved. Examples are presented of how numerical modelling can be used to investigate fundamental aspects of rock mass behaviour. It is demonstrated that an important consequence of change in scale is that the mechanisms of failure also change. The complex failure of the footwall slope at Aznalcollar, a large open-pit mine in southern Spain, is discussed. Numerical modelling with UDEC (universal distinct-element code) has allowed the realistic simulation of displacements measured in the field

Jun 18, 1905

By O Otgonbayar, B Bayarmaa, D Batbyamba, S Amar-Amgalan, K H. Natsagdorj, J Nomin-Erdene, B Boldkhuu, T S. Sainzaya

The Argyle deposit in the Kimberley region of Western Australia was the world’s largest accumulation of natural diamonds. Following its discovery in 1979, the mining of associated alluvial diamonds commenced in 1983, followed by the pipe in late 1985. Over the life of the mine to its closure in November 2020, Argyle produced approximately 900 million carats of diamonds. Argyle diamonds are distinctive in having a predominance of brown colours and rare highly-prized pink diamonds, which are a signature of the deposit. The 3D geological model developed from mining and deep drilling shows that Argyle is a composite pipe formed by the coalescence of several steep-sided diatremes, each with their own feeder zones at depth, that were erupted along a NNE-trending fault. The ~1.2 Ga Argyle pipe is comprised of diamondiferous olivine lamproite volcaniclastic rocks and intruded by sparse olivine lamproite dykes. The volcaniclastic rocks are predominantly comprised of unconsolidated quartz-rich lapilli and coarse ash deposits formed by numerous phreatomagmatic eruptions of olivine lamproite magma through Mesoproterozoic water-rich sands and silts. Post-emplacement deformation has tilted the orebody 30° to the north and regional strike-slip faulting has offset, segmented, and elongated the orebody. Recent significant modifications of the geological model resulted from underground block cave operations, producing several critical lessons learnt. Diamond grade and quality reconciliation issues warranted a geological investigation which resulted in the recognition of new volcaniclastic olivine lamproite domains with a broad range of diamond grades, including some very high-grade units. The new lamproite domains had a significant effect on the block cave mining and resultant recovery of diamonds. The new findings enable a more coherent and detailed geological understanding of the volcanic emplacement and paragenetic sequence of the Argyle AK1 pipe. Structural modelling of the deposit also played a major role in the block cave mining tonnage recoveries and daily operations. The re-examination of the geology of the Argyle pipe and the results of this new information reinforces the need for ongoing robust geological work both in the early stages of mining a deposit and continued during the life of the mine.

Mar 22, 2022

By H. W. J. P. Neomagus, J. R. Bunt, D. L. Botha, N. T. Leokaoke

Coal briquetting traditionally makes use of high-dosage, nonpolymeric binders (such as coal tar pitch or molasses) or polyvinyl alcohol (PVA) at low dosages for the binding of fine and ultrafine coal. Due to constraints associated with the manufacturing and cost of PVA-bound briquettes, a novel polyacrylic binder was developed that could possibly be added in low dosages at room temperature. A set of formulations of two polyacrylic components (components A and B) was developed, from which an optimal binder mixture was determined. This formulation comprises 40wt.% component A and 10wt.% component B with a 0.04wt.% cross-linking additive, and the balance water. The uniaxial briquette compressive strength was used to obtain the optimal binder mixture. The binder mixture was added to the coal powder in dosages from 0.1 to 1.2wt.%. Mechanical tests and thermogravimetric analysis in an oxidized environment at a maximum temperature of 930°C were conducted. Binder-bound briquettes were compared to binderless briquettes and PVA-bound briquettes. Briquettes made from the polyacrylic formulation had uniaxial compressive strengths double that of the binderless briquette yield strength, as well as the minimum recommended compressive strength of 0.375 MPa. The organic binders did not affect the combustion of the briquettes, since the results compared well with the binderless briquettes. The polyacrylic formulation is considered to be a possible substitute for PVA in terms of mechanical and thermal properties and raw material cost.

Mar 1, 2021

By Nicholas P. Gura

This paper presents the analysis, design, and load test program results for drilled shafts to support a 70-story hotel tower and associated 10 story podium structures located in Las Vegas, Nevada. A mat foundation for the structure, although feasible, would have produced undesirable differential settlements within the high rise tower footprint and at the interface with adjacent lower level podium structures. The resulting foundation system solution for the 70-story, approximately 800-foot long hotel tower was four-foot diameter drilled shafts, extending 100 below shaft cutoff. The design compression capacity for the four foot diameter drilled shaft was 5,000 kips. The load test program proved that the unique Las Vegas valley geology lends itself to efficient installation, precluding the need for engineered slurry or casing. The load testing program included the installation of two four-foot diameter test shafts to 100 feet below theoretical cutoff and the performance of two highly instrumented independent Osterberg load cell tests with maximum sustained test loads of 12,000 kips. Sonic caliper testing was also performed to document actual in-place shaft diameters and verticality. The load test program also provided information necessary for the foundation design of the podium structures. In addition to the tower?s drilled shaft load test program data, continuous flight auger (CFA) pile evaluation and testing was also performed. The CFA testing consisted of traditional ?top down? loading techniques and was performed as an alternative to the recommended shallow drilled shafts for the lower level podium structures. The results of the CFA test program provided supplemental, insightful soil friction data which was used in conjunction with the drilled shaft test program data in evaluating the most appropriate support for the lower level structures.

Jan 1, 2007

By N. Chow

The recovery of manganese from lower-grade resources has been studied for a number of years. Of key importance in prior work was the discovery that higher-valent manganese can be readily leached with sulfurous acid. This eliminates the need for high-temperature reduction roasting that is conventionally used in processing high-grade material. High-temperature roasting is energy intensive, emits a large amount of carbon dioxide and would not be economical for processing lower grade material. While the prior work provides important information for extracting manganese from lower-grade resources, the production of unwanted byproducts and high water and energy usage has limited its commercial use. This paper describes the results from laboratory work that demonstrate solutions to problems that to this point have precluded commercial development. Preliminary mass and energy balances show that a significant opportunity exists in producing manganese with this hydrometallurgical scheme in a low-cost, environmentally friendly manner. The emphasis of the work is on low water use, low overall energy use and economic destruction of unwanted byproducts.

Feb 1, 2012

By Jiang Shuguang, Zhang Huicheng, Wang Xingshen

Based on the experience about determination of properties of the main fan in mine shaft, this paper relates at length how to reasonablly select test system, test methods and test instruments, how to appraise the reliability of determination results, and how to effectively control the adjusted air etc. The merits and demerits of the two methods of determining air with Nine- Anemometer and Pitot meter are compared.

Jan 1, 1991

By B. J. Sauer

Variable frequency drives (VFD’s), or adjustable frequency controls (AFC’s) as they are more precisely identified, have been available to the mining industry for over 20 years. However, in recent years as the push to cut production costs has become ever so crucial, AFC usage has become more widespread. This paper seeks to provide professionals in mineral processing plant design and operation with an introduction to AFC’s, insight as to why AFC control for AC induction motors can be advantageous, and specification and design considerations.

Jan 1, 2002

By Wm. D. Jr. Sheldon

THIS paper presents practical data to aid in the selection of a mine ventilating fan, and outlines considerations to be made to ensure satisfactory operation and optimum efficiency of the fan. Much has been published on the general subject of mine ventilation, but the writer has found few specific data on factors and considerations which govern the selection of a fan-data which should be available to the operator if his fan is to give satisfactory service within the range of the high-efficiency portion of its performance curve and deliver the specified air capacity when operating against the anticipated range of resistance of the mine. The total quantity of fresh air furnished by the ventilation system must be adequate to provide, and to ensure at all times, safe and healthful working conditions in the mine. It is assumed that the mine operator is able to determine the air quantities required for the various parts of the mine.

Jan 1, 1941

By Sheldon P. Wimpfen, Ralph H. Sweefser

FOR centuries the pumping of water has been one of the chief problems to be overcome by the persistent men who win the mineral wealth of the world. Profitable operations have often been forced to suspend activities as the mine penetrated well below the water table or when sudden rushes of water were encountered. To operate below the local water level requires continuous pumping equal in volume to the amount of water flow¬ing into the mine workings. Often the water to be removed exceeds the tonnage of valuable material produced. To be above local water level is a valuable asset. Modern mining practice permits nothing short of the extraction of the last pound of profitable ore from a mineral deposit. In the days before the development of mechanical and electrical power as we know it today. water in any quantity was a major

Jan 1, 1948