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By Lance Rasband, Richard Hanke, John Starcevich

"Mining on Seattle’s SR99 tunnel began in July of 2013. Initial mining progressed slowly through a 4.5 m (14.9-ft) thick fiber-reinforced concrete headwall before immediately entering the first of three planned safe havens. Once through the headwall and safe haven the machine would move through roughly 122 lineal m (400 ft) of jet grout improved soil at a rate of slightly more than 1.6 m/d (5.3 ftpd). It was anticipated that once mining has passed through the improved area, “Bertha” – now the world’s second largest tunnel boring machine (TBM), would be moving at a rate of almost 11 m/d (36 ftpd). By the end of October 2013, Bertha had mined roughly 131 m (430 ft), averaging 1.4 m/d (4.7 ftpd), and had begun mining within native soils. By the start of December 2013, tunneling had reached the 244 m (800 ft) mark and Bertha was averaging 3.6 m/d (11.9 ftpd), achieving as much as 12.8 m (42 ft) of progress on given days. Unfortunately, on Dec. 6th, 2013, Bertha began to stumble and all progress quickly came to a halt.Initial reports stated an obstruction had stopped Bertha in her tracks. The preliminary investigation involved installation of 10 deep dewatering wells to reduce the hydrostatic pressure within the ground around the TBM, to allow the contractor’s personnel to inspect the cutter head from within and also to investigate for the presence of obstructions at the face of the cutter head. During inspection, the contractor’s crews found fragments of steel pipe entangled in the cutter head. The steel was apparently from an abandoned 254 mm (0.9 in.) diameter monitoring well casing, previously installed by the Washington State Department of Transportation (WSDOT) to monitor groundwater conditions for the design and planning of this tunnel project. After the steel was removed from the cutter head and cleared from Bertha’s path, she attempted to move forward but was only able to generate a slow crawl."

Jun 1, 2016

By Richard W. Cannon

INTRODUCTION The authors, by means of this paper, will attempt to show the role of Induced Polarization and Resistivity surveys in the discovery of the orebodies of Gibraltar Mines Limited (N.P.L.). In this paper, we will also attempt to show the importance of conducting large enough surveys in order to properly evaluate the results obtained from these surveys. LOCATION The orebodies of Gibraltar Mines Limited (N.P.L.) are located on the western slope of Granite Mountain, central British Columbia (52°30' north, 122°16' west) (See Fig. 1). The property lies approximately 28 miles north of Williams Lake, B.C. and can be reached by way of 10 miles of newly improved road from McLeese Lake, on the Cariboo Highway. The area in and around Gibraltar Mines has a moderate topographic relief with elevations between 3,500 and 4,100 feet. {EARLY HISTORY AND GEOLOGY The present Gibraltar Mines property before amalgamation consisted of the Pollyanna property (Duval-Canex) and the Gibraltar property (original Gibraltar Mines) as well as some Coast Silver and McLeese Lake Copper claims (See Fig. 2). The Pollyanna property was first described in the 1917 B.C. Minister of Mines Report which referred to it as the "Rainbow Group". The development at that time consisted of several open-cuts on copper bearing quartz veins.

Jan 1, 1972

By W. E. Lytle

Environmental permitting is a critical component for joint-venture projects located in the Commonwealth of Independent States (CIS). This paper presents the basic CIS regulatory environmental requirements for permitting of a hypothetical mining source and emphasizes air permitting. Topics which will be covered include: the Expertiza process, air pollution quantification, data requirements, and air pollution modeling protocol. A comparison will be made between permitting requirements for air pollution sources in the United States and a CIS country, Kazakstan.

Jan 1, 1998

By Paolo M. Brion, Z. Bade Sozer

"The Bypass Tunnel has high head conditions ranging from a minimum of 600 feet (183 m) under the Hudson River to a maximum of 875 feet (267 m) on the west side. The ground cover ranges from 425 feet to 900 feet (130 to 274 m). A two-pass lining is designed for the Bypass Tunnel. The bolted, gasketed precast segments carry the temporary hydrostatic and permanent ground loads. After the tunnel is put into service, the design assumes that the final lining, which varies from reinforced concrete to reinforced concrete with steel interliner, will carry the permanent hydrostatic loads. The design head for the segments is assumed at 775 feet (236 m), and the internal operating pressure head is around 1,200 feet (366 m). This paper discusses the design hydrostatic head and different load conditions considered for the segments, the load sharing between the segments and final lining, and the means employed to control water and hydrostatic pressure. PROJECT BACKGROUND The Rondout-West Branch Tunnel (RWBT), a segment of the Delaware Aqueduct, was built from 1937 to 1944 and provides about 50% of New York City’s total water supply. Monitoring and tunnel operations have shown that the RWBT is leaking up to 35 million gallons per day (MGD) (132.5 million L/day). In particular, two locations have been identified as areas of concern: Roseton and Wawarsing, as shown in Figure 1. The Wawarsing reach of the aqueduct will be repaired with an extensive grouting program when the RWBT is unwatered. However, because of the extensive nature of the leakage in the Roseton area, a Bypass Tunnel will be constructed to divert the flow around this area."

Jan 1, 2016

By S. A. Ghoreishi-Madiseh

Underground mines, with their relatively high ground temperature and their extensive backfilled stopes provide a great opportunity for producing geothermal heat. The novel idea of installing a network of heat exchange tubes into stopes prior to backfill placement converts each mine stope into a heat producing battery. In this system, backfill plays the role of the heat exchange medium conducting heat from the surrounding rockwalls to the heat exchange tubes. This geothermal heat can be used for heating: mine facilities and buildings, the intake air, a close-by mineral processing plant, or even nearby communities. This paper investigates the possibility of extracting renewable geothermal energy from backfilled mine stopes by means of closed-loop geothermal cycles. To simulate realistic operational conditions a heat transfer model is developed and solved numerically. To evaluate the numerical results, a small scale physical model is constructed and the experimental results are compared with the simulation results. The study estimates the sustainable rate at which heat can be extracted from a typical underground mine stope, the resulting outlet temperature and performance of the geothermal system. The results show that mine stopes are capable of sustainably producing geothermal heat not only when the mine is active, but also after the depletion of the ore body. Therefore, an underground mine will no longer be perceived as an enduring economic liability, but as a long-lasting source of clean, renewable, and inexpensive low-grade geothermal heat.

Aug 1, 2013

By Patrick R. Taylor

Thermal plasma technology has a wide range of applications in extractive and process metallurgy. Beneficiation of complex ores, oxide reduction, melting/remelting of refractory metals and scrap, and the recovery of precious metals from waste products are some examples of potential uses for plasma technology. The highly concentrated enthalpy provided by plasma torches is a cleaner energy source and may give higher processing rates per reactor volume than conventional technologies. Some of the other advantages may be: controlled furnace atmosphere, ability to treat fine feed materials and rapid quenching. A review of some of the uses for plasma processing in non-ferrous process and extractive metallurgy is presented.

Jan 1, 1993

By M. M. Oosterveld

"In South West Africa diamonds are mined from ancient beach deposits by the Consolidated Diamond Mines of South West Africa, Limited.To improve the control of mining production, a computer is used for the calculation of statistically more accurate and homogeneous ore blocks. Geological and sampling information has been digitized and stored on magnetic files.The figures derived for each block entail the calculation of the diamond size frequency distribution, the diamond density distribution and the ore reserve by using the density distribution.The diamond size frequency distribution is used for estimating the revenue in an ore block.A description is given of how a linear programming system can be used for production planning."

Jan 1, 2014

By G. J. Mei

Separation of hematite and iron-containing silicate gangue - aegirine by Flotation using fatty acid collector and (NH4)2SiF6 depressant was investigated in this paper. The flotation tests with single minerals show Ammonium hexafluorosilicate (AHFS) is a selective depressant for aegirine in hematite flotation in weakly acidic medium, which can strongly reduce the flotation recovery of aegirine in the pH range of 4~5 while has no evident effect on the flotation of hematite. The results of flotation tests with actual ores show the separation of hematite from aegirine gangue by forth flotation was possible, and good selectivity was achieved. Chemisorptions were observed on aegirine mineral surface treated by AHFS solution by using SEM and IR spectrum measurements. On the basis of coordination chemistry, a comprehensive mechanism, which reasonably explains the selective depression of AHFS for iron-containing silicate, is also proposed.

Jan 1, 2014

By Richard L. Jenkins

Systematic sampling, in reconnaissance fashion, of the continental shelves of the United States to define favorable areas of offshore mineral deposits, is one of the long-range marine mineral; programs of the U.S. Department of the Interior. In mid-1966 the Department of the Interior launched its Heavy Metals Program to stimulate domestic output of gold which is in serious short supply. The program is jointly conducted by the Geological Survey and the Bureau of Mines.

Jan 1, 1968

By C. F. Johnson

Nearly all of the sulphur produced in the world today is converted to sulphuric acid and 49 % is used in the manufacture of fertilizers. In the last few years we have seen the beginning of another chapter in the volatile history of sulphur as the severe shortage of 1963:-67 has been transformed into present-day surplus. Prospects for further aggravation of this situation in the years ahead seem assured. In 1970, western world production showed a rate of increase of 4 -5%, which 1S somewhat less than that of 8% for the period 1963-1967. The rate of growth of consumption dropped considerably in 1968 when the demands of the fertilizer industry fell. During the same period of time, wide-spread demands have been set in motion for a clean environment which indicates that a fundamental change in sulphur supply, demand, and even sources, is likely to result from this upheaval. The sale of sulphur by Poland to the western world has increased and for 1970 was estimated at over one million metric tons. In the next few years, increase in Canadian sulphur supply will stern from two sources;

Jan 1, 1972

By Binbin Luo, Northeastern University, Chuanyao Sun, Jie Liu, Yimin Zhu, Yanjun Li

"A series of new type collectors a-bromo-saturated fatty acids, CH3(CH2)5CHBrCOOH (a-BHA), CH3(CH2)7CHBrCOOH (a-BDA), CH3(CH2)9CHBrCOOH (a-BLA), CH3(CH2)11CHBrCOOH (a-BMA) were synthesized from saturated fatty acids and bromine by solvent-free method (Hell-Volhard-Zelinski reaction) in laboratory. The micro-flotation tests of quartz mineral were conducted at a relatively low temperature of 15 °C. The adsorption mechanism of such collectors on quartz mineral surface were established by zeta potential measurements, in conjunction with the results of quartz micro-flotation tests. The flotation results showed that the collecting ability is in the order of a-BMA > a-BLA > a-BDA > a-BHA for the flotation of quartz mineral, which also demonstrating that the a-bromo-saturated fatty acids (a-BFAs) are new selective collectors for reverse flotation to remove quartz mineral from iron ores at a relatively low temperature.INTRODUCTIONThe requirement of higher pulp temperature to maintain the activity of fatty acid anionic collectors which have been widely applied in technological process of iron ores reverse flotation lead to a great deal of energy consumption.The purpose of this paper is to synthesize a new modified collector with carbon chains from eight to fourteen atoms, with strong electronegativity bromine atom introduced into a-carbon position to improve the activity and solubility of the reagent so that it can be adopted at a comparatively low pulp temperature. The collecting performances of these new collectors on quartz surface were studied, and the structure - properties were discussed in light of zeta potential measurements and quantum chemistry calculations."

Jan 1, 2016

By A. Habibi

The FMC Westvaco Trona Mine is located near Green River, Wyoming and has an annual production of 4.5M tons. Trona is an evaporite mineral that is processed into several products, mostly soda ash. The underground mine has two active development panels and one longwall (LW) panel. The mining horizon is about 500m below surface and the surrounding strata liberates methane. Three surface-based, blowing fans provide ventilation air as a positive pressure system. The mine operates a 225m long LW face, built by Joy Mining Machinery. Headgate and Tailgate developments are driven with four entries. The recovery room, at the end of each panel, is 8m wide with three access chutes. Additional recovery room support comes for concrete blocks used with a center to center spacing of 1.5m. As the LW enters this pre-driven recovery room there are notable responses and shifting ground stresses. This study was undertaken to measure the ground response using seven vibrating wire displacement transducers. These devices were used to monitor the convergence as the LW approached the recovery room. The methane concentration in the air ventilating the recovery room was also monitored. The correlation between convergence and gas liberation was then studied. The results show that the convergence varies from 0.1m to 0.25m along the length of the recovery room. Ventilating the recovery room becomes critical as methane is liberated from oil shale as the more plastic floor material is disrupted. Appropriate methods are employed to ventilate the recovery room.

Feb 23, 2014

By Jeffrey H. Welsh

The Bureau of Mines studied the use of computerized, continuous, remote monitoring systems for safety from power system faults in underground coal mines. In this report the need to improve protection against power system faults is documented, and types of faults are identified. The relationship between mine safety regulations and computerized, continuous, remote monitoring is analyzed.

Jan 1, 1983

By Henrique Kahn, Daniel Uliana, Carina Ulsen, Guilherme Nery

"Gold has been a material in high demand since the dawn of humanity. After hundreds of years of exploitation, the increasingly search for gold occurs in lower grade deposits with greater extraction difficulty. Therefore, for maximum efficiency, deep knowledge of the characteristics of these minerals and their associations is crucial, which is acquired through an accurate and rigorous routine of process mineralogy and batch extraction tests. The industrial gold process extraction occurs by gravity concentration, sulphides flotation and cyanidation. For gravity concentration, it is fundamental to establish the proportion of free or coarse gold grains and its association to heavy minerals; regarding flotation, the most relevant data are the proportion of gold associated to sulphides and their liberation by the surface area; for cyanidation, it is crucial to evaluate gold accessibility and the kinetics of leaching. Thus, the characterization of gold associations and liberation is vital to establish the plant design, to optimize operating plants and to reduce gold losses. Our aim is the characterization of gold occurrence in low-grade Brazilian deposits with complex mineralogical assemblages to support processing flowchart definition and to predict metallurgical recoveries. Gold distribution in light and heavy minerals was evaluated by heavy liquid separation and the occurrence of gold in free or locked particles was carried out on heavy products by SEM-based automated image analysis using the MLA system. All the products of heavy liquid separation were cyanidated in head samples with different milling conditions to evaluate the reaction kinetics and maximum recovery."

Jan 1, 2014

A line of nine self-aspirating W emco cells, part of the Rougher circuit at Division Salvador, Codelco Chile, was retrofitted to allow operation with forced air. Each cell could be operated self-aspirated or with compressed air supplied through a 4-inch line equipped with a mass flow meter. Gas dispersion was characterized for the two modes of operation. Metallurgical performance was compared under self-aspirated conditions and with different gas profiles under forced air conditions. Cell characterization demonstrated that with forced-air the cells could not evenly distribute air across the cell volume. Bubble size increased with gas velocity, as expected, with no difference between self-aspirated and forced-air operation. A systematic increase in bubble size down the bank was found. Cumulative bubble surface area flux down the bank showed no major differences between surveys. However, grade-recovery curves revealed that the highest recoveries were invariably obtained with forced air operation. Plotting concentrate mass recovery vs. enrichment ratio showed that the line performance could be controlled over a wider range when forced air was used.

Jan 1, 2007

By N. Acarkan

Slags usually contain some quantity of valuable metals. They are actually a secondary resource of metals, rather than an end-waste and have been utilized as a resource material in many areas. In addition, for some applications, slags have comparable or even better properties than their competitors. Leaching is a method for extraction of metals from copper slags. The extraction of metals such as copper and cobalt from the copper slag of Küre-Turkey, was investigated in the past decades. Fayalitic type of these copper slags containing 0.934 % Cu, 0.353 % Co and 50.91% Fe were subjected to the experimental study. As a result of mineralogical analysis of the slag sample, fayalitic type of slag was found to contain hercynite, magnetite, hematite, pyrite, chalcopyrite, covellite, bornite and metallic copper. Direct acid leaching methods were applied on the sample. Effects of leaching time, temperature and acid concentration on Cu and Co leaching recoveries were investigated in the direct acid leaching. The optimum leaching conditions were found as leaching time of 2 hours, solid/liquid ratio of 1/3, H2SO4 concentration of 125 g/L and temperature of 70 °C. At these conditions, 75.5 % of Cu, 95.6 % of Co and 70.9 % Fe were extracted. In the second stage of the leaching experiments, copper in the pregnant solution was precipitated by cementation to produce a Cu concentrate assaying 95.58 % Cu; cobalt was obtained by precipitation with H2S to produce a concentrate containing 62.10 % Co. As a result of this study a process flow sheet has been developed for recovering Cu and Co from these slags to demonstrate its economic and technological benefits.

Jan 1, 2014

By E P. Graham

Orebodies occur in an infinite variety of grades, shapes and sizes, and take many millions of years to grow. When extraction starts there is only one possible end -the mine sooner or later will run out of ore and shut down. If the mineral industry is to supply the ever increasing demands of modern civilizations, more and more metals must be found and mined. This will require a never-ending search for ore, and the development of every economic body, large or small. To justify the mining of a small orebody, it first of all must pay its way. If the size of the burden imposed by the capital cost estimates is not carefully worked out, an otherwise promising situation could be killed. The very nature of mining, as a transient industry, re-leases a steady stream of good used equipment, and the trained personnel to install and operate it. All manner of plans and layouts, which can be utilized at a new property, are available. Working these and other economies into the estimates will sometimes make enough difference to give a prospect the green light.

Jan 1, 1964

"The research aimed at solving the problem of measuring instantaneous local physical quantities for multiphase flows in mineral processing, which are common in minerals industry and with significant challenges. Due to the lack of proper measurement tools currently in minerals industry, multiphase flows (such as in flotation cell) are treated as in a “black-box”. It is crucial to develop measurement technique by which the acquired processing data can be used for process optimization and control. By measuring the conductivity distribution across a measurement area, Electrical Resistance Tomography (ERT) has been adopted by many researchers to monitor and investigate many processes involving multiphase flows in other industry sectors. A compact ERT probe was built and then used to measure the conductivity distribution within a few flotation machines. In a flowing foam flotation column, the results showed that ERT can accurately measure the change of liquid content (high conductivity fluid distribution). In another part of work, based on the Green-Kubo relations, ERT can measure turbulence via the fluctuation of conductivity caused by bubbles moving through the measurement area, changing the density of the fluid. The tests with the Metso 3 m3 RCS flotation cell were also carried out for turbulence measurement under different air rates and impeller speeds. The results of flotation cell from ERT measurement showed that varying impeller speed had more pronounced influence than changing air rate. When impeller speed is increased, the size of the high turbulent zone increases. ERT is a powerful technique that has the potential to be used for a wider range of applications. The future work will be carried out with more case studies and expanded to more processes such as leaching process, high temperature flows in further downstream production chain (steel making process and alloy manufacturing process).INTRODUCTIONMultiphase flows constitute a majority of the naturally-occurring and industrially-relevant flows, especially in mineral processing. Some of the measurement techniques have been used for the study of fluid characteristics. Optical techniques such as Laser Doppler Anemometry (Kyselaa et al., 2013) and Particle Image Velocimetry (Nobach and Bodenschatz, 2009) can produce accurate measurement results with high spatial and temporal resolution, but their applications are limited to transparent flows. Hot wire probes (Amini et al., 2013) have high spatial and temporal resolution in turbulence quantification, but they are susceptible to environmental factors."

Jan 1, 2018

By Jiachen Wang

Longwall top-coal caving mining is one of the major mining methods for extracting thick coal seams in China. The top-coal caving longwall mining was began to use in the 1980s in China, and got the rapid development. The development of the top-coal caving mining technology in China, the achievements and the theoretical aspects progress of this method are described in detail in this paper. And the main technical model of China's top-coal caving mining is introduced in this paper. This paper also introduces the application of large-cutting-height mining in China and the technical level it has reached.

Aug 1, 2013

By F. Chen, L. J. Gaydos, D. C. Kuhn, Demersm L. M., S. C. Sun

"Summary: In this report the differential regulation of NF-KB and nitric oxide (NO) was investigated in the mouse macrophage cell line RAW 264.7 following exposure to a mineral dust (silica) and /or an endotoxin (Lipopolysaccharide, LPS). The results indicated that silica and LPS can significantly induce the activation of NF-KB as well as elicit enhanced production of NO in RAW 264.7 cells as part of an early inflammatory response mechanism. A 24-hour time-course study showed that NO release from these cells continued to increase following the initial stimulus by LPS or silica. In contrast, activation of NF-KB was maximal at 6 hours and then showed a steady decline to 24 hours. The production of NO was suppressed by protease inhibitor and antioxidant, both of which block the activation of NF-KB. Surprisingly, the use of an NO synthase inhibitor resulted in an enhancement of NF-JCB activation. These findings suggest that NO produced in macrophage cells in response to an inflammatory stimulus like silica or LPS my be linked to a negative feedback role on the activation of NF-KB. It is now accepted that nitric oxide (NO) plays a pivotal role in the inflammation response process when macrophage cells are activated by a pro-inflammatory stimulus (l). Production of NO is dependent on the activity of the enzyme nitric oxide synthase (NOS). Up until now, at least three distinct genes have been described which encode different isoforms of NOS. NOS has been cloned from a variety of different mammalian cells, including constitutive neuron NOS, constitutive endothelium NOS and inducible NOS (2). Macrophages appear to be the principal cellular source for the inducible form of NOS (iNOS) activated in response to an inflammatory producing event. The mechanisms subserving the regulation of the iNOS gene and NO production have been under intense investigation in recent years (3-5). Several binding sites for transcriptional factors have been identified in the promoter region of iNOS gene, including NF-lCB, AP-1, NF-IL6, Oct-I to cite a few (5). NF-KB appears to play a"

Dec 1, 1996