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By Renfeng Song, Shaoyan Wang, Zhiqiang Zhang, Ke Guo

Leaching titaniferous magnetite concentrate with alkali solution of high concentration under high temperature and high pressure was utilized to improve the grade of iron in iron concentrate and the grade of TiO2 in titanium tailings. The titaniferous magnetite concentrate in use contained 12.67% TiO2 and 54.01% Fe. The thermodynamics of the possible reactions and the kinetics of leaching process were analyzed. It was found that decomposing FeTiO3 with NaOH aqueous solution could be carried out spontaneously and the reaction rate was mainly controlled by internal diffusion. The effects of water usage, alkali concentration, reaction time, and temperature on the leaching procedure were inspected, and the products were characterized by X-ray diffraction, scanning electron microscope, and energy dispersive spectroscopy, respectively. After NaOH leaching and magnetic separation, the concentrate, with Fe purity of 65.98% and Fe recovery of 82.46%, and the tailings, with TiO2 purity of 32.09% and TiO2 recovery of 80.79%, were obtained, respectively.

Jun 16, 2021

By Robert E. Kirby

The potash mine and refinery of AMAX Chemical Corporation is located 26 miles east of Carlsbad on the north end of the potash producing areas. This property was developed between 1949-1952 and production of muriate began in August 1952. Two shafts, located 400 feet apart, were sunk to the ore zone 900 feet below the surface. A 15-foot diameter ore hoisting shaft equipped with a 1000-ton ore pocket, crusher and automatic skip loading equipment plus a 20-foot diameter service shaft with a curtain wall for exhausting air were provided. Sylvinite production to date has been from the first ore zone, stratigraphically, the lowest of ten identified mineralized zones in the salt section. This first ore zone has been the top producer of Muriate of Potash over the years. In our area we do have some very marginal mineralization in the third ore zone some 35 feet above the first. We have not mined from this seam as yet but we are investigating the economics very closely with access slopes and an experimental mining panel. Our ore seam is generally flat lying but does have local gentle rolling with grades from 2% to 5%. The mine was designed and developed from the beginning with conventional mining practices and rail haulage from the mining section to the ore pocket. As mining progressed in the early years, production increased from less than one million tons annually to a maximum of 3,935,000 tons in 1964. Efficiency also kept pace with the increasing production and continually improved until the efficiency of the production crews reached an average of 100.3 tons per manshift in 1964.

Jan 1, 1974

By M. Mustafa Kahraman, Sean Dessureault, W. Pratt Rogers

Most contemporary mines have considerable amounts of data. Structured and unstructured large data sets are colloquially named big data. Much of the data in mining operations come from a variety of systems, each with different databases and reporting environments. Standard technology deployments create a Bsilo-ification^ of data leading to poor system benefit. Through modern server monitoring and systematic approach, data utilization and value can quantifiably be measured. The Data Utilization and Value Index (DUVI) can quantify business intelligence best practices and user interaction. This study seeks to provide a data management tool to measure data utilization across the process of converting data into action.

By J. Stawovy, A. Fourie, J. D. Quaranta

Coal refuse impoundments are disposal facilities specifically designed for the coal mining industry. Re-purposing refuse impoundments for co-disposal with natural gas flowback water and waste rock overburden has been investigated. The aims of this study were to investigate properties of coal refuse classification under the influence of co-disposed wastes as geochemical material exposure pathways from hydraulically exposed sodium and calcium ( Na+, Ca2+) cation loading from disposal of flowback water produced during the development of horizontal drilled natural shale gas frack wells, and waste rock having limestone characteristics. The geotechnical index classification of saturated cohesionless refuse is required to evaluate the liquefaction potential for strain or strength loss contributing to ground movements. This study is relevant to identifying changes in the coal refuse geotechnical index classification as sand-like, clay-like, or a borderline transitional material from the effects of ion and waste exposure in the impoundment’s reservoir porewater. Laboratory geotechnical tests were performed on fine coal refuse blended with different cations to classify the altered plastic behavior and index classification. Following determination of the index classification, the specimen’s stress–strain responses were investigated through isotropically consolidated undrained (ICU) triaxial compression tests. This experimental study culminated with two salient findings: the first is that introduction of ions alone into the refuse tailings or impoundment porewater resulted in significant material changes in property index classification, and the second finding was that the difference in refuse index classification did not correlate into noticeable effects of the monotonic undrained triaxial strength parameters.

Jul 5, 2022

By William C. Dixon

Since the mid 60's, several haul cycle simulation programs have been developed. However, most of these programs are believed to employ the continuous, rather than the discrete, event-oriented simulation approach to determine the haul cycle times. This paper describes the recently developed haul cycle simulation approach where time is advanced in varying amounts only as the system changes occur. This approach results in greater computational accuracy and increased computational efficiency. The program is written in FORTRAN and requires equipment performance curve and haul road profiles as input. Unique program capabilities include the handling of switchbacks and intersections. The program uses a master data file concept in which various haul road profiles found during the mine life can be simulated all in one job submission. The results of the model validation using the actual time study data provided by an open pit mine operator near Tucson, Arizona, are also described in this paper.

Jan 1, 1978

By Margreth Tadie, Chalwe Chibwe

Physicochemical properties of copper electrolytes are a strong fundamental consideration in electrodeposition processes during electro-purification and recovery of copper. Their influence extends to mass transfer as well as energy consumption during the electrodeposition process. In this study, the influence of electrolyte composition on electrolyte physicochemical properties was investigated to review the existing literature data. This review of data is considered necessary as more and more electrowinning models are being developed for process prediction and optimisation and a need of such data is required for accurate prediction of physicochemical properties. The major components of importance to the formation of smooth high-quality and high-purity copper cathodes at optimum current efficiency are considered the species in solution. These include Cu ions, Fe ions (major impurity), H2SO4, and a smoothing agent additive. A 5-factor, 2- and 3-level experimental design was employed to determine the effect of copper (35 and 45 g/l), sulphuric acid (160 and 180 g/l), iron (1, 3, and 6 g/l), polyacrylamide additive (2, 5, and 10 mg/ l), and temperature (45 and 55 °C) on electrolyte density, conductivity, and the diffusion coefficient in synthetic copper electrowinning electrolytes. The major species in a copper electrowinning electrolyte are found to be the most relevant for prediction of physicochemical properties. These results indicate that relatively simple empirical models are sufficient for modelling of the electrolyte domain in electrowinning, without the need for the generation of vast amounts of complex experimental data.

Feb 1, 2021

By H. Murray

Introduction Industrial minerals are key ingredients in a large majority of domestic and industrial products that are used in our daily lives. In the 7th edition of Industrial Minerals and Rocks, fifty three industrial mineral commodities are described. A precise definition of industrial minerals and rocks is difficult. Bates (1975) proposed a definition which is widely used and is as follows: "any rock, mineral, or other naturally occurring substance of economic value, exclusive of metal ores, mineral fuels, and gemstones: one of the non-metallics". They can be igneous, metamorphic, or sedimentary and range in price from a few dollars per ton to a very high price of hundreds of dollars per ton. The growth in their production and use is closely allied with population growth particularly in countries that maintain a high standard of living. The United States just passed 300 million in population and it is predicted that by 2040 the population will be 400 million. This will result in large increases in the need for Industrial minerals. Other factors that relate to increased use of industrial minerals are increased research and development by the producing companies and better quality control. Many industrial minerals such as kaolin, barite, nepheline syenite, fluorspar, lithium carbonate, phosphate rock, potash, talc, and several others are exported from the producing countries to many users around the world which has significantly increased their use. Also, government agencies, State Geological Surveys, and Universities have contributed to their growth by their research and development activities.

Jan 1, 2007

By B. P. Sullivan

This paper describes how the author projected the economic benefits of a proposed coal liquefaction project based in Pennsylvania. These benefits were assessed in a successful effort to garner government support for the project. The projections considered such issues as increases in employment, wages, and tax receipts to state and local government, plus other less-obvious benefits, such as site remediation. The paper explains how sponsors of similar projects can use economic projections in making meaningful and compelling presentations to federal, state and local authorities.

Jan 1, 2000

By Manoj Khandelwal, Minghui Liu, Jian Zhou, Kun Du

The waste rock and tailings backfill into the mined-out areas are the most effective method for solving the environmental pollution and surface disasters for nonferrous metals mines. In practice, the success and availability of backfill operations are dependent on the slurry fluidity and the strength properties of cement backfill. The transport of the slurry through the pipeline to the designated backfilling area relies on its eximious flow properties, while the appropriate strength of the filling body ensures the safe operation of the stope. In this paper, the effects of cement and aggregate types on the slurry fluidity and strength characteristics of cemented backfill are studied in detail, which are often ignored in other pieces of literature. Diffusivity is used as an indicator to evaluate the slurry fluidity. Various slurries whose concentrations ranging from 70%, 73%, 75%, 78%, and 80% are made with different aggregate ratios and cement-sand ratios are tested. It has been shown that slurry fluidity is inversely related to its concentration, but 78% is the “stopping point” for the deterioration of fluidity. The addition of rod-milled sand improves or worsens the cemented backfill (CB) strength depending on the amount of rob-milled sand. The uniaxial compression experiment results on 216 CB specimens produced by different combinations of influencing variables showed that CB specimens made from cement with superior mechanical properties have a higher uniaxial compressive strength (σucs). It has been also found that the effect of aggregate ratio on the CB strength is not singular, but works in conjunction with the curing time and the cement-sand ratio. The longer the curing time and the higher the cement content, the higher the CB’s σucs. To avoid the time-consuming and costly problem of obtaining the strength of the CB from indoor experiments, an SVR model capable of predicting the uniaxial compression strength of CB specimens is proposed, which is optimized by genetic algorithm (GA) and particle swarm optimization (PSO) algorithm. The results of the three performance indexes (MAPE, MSE, and R2) show the superior performance of the GA-SVR and PSO-SVR models and the agreement of the predicted results with the experimental results, which indicate that these two models can accurately predict the σucs of CB.

Feb 3, 2022

By David W. Wisecarver

Kennecott Copper Corporation and the U. S. Bureau of Mines cooperated in a full-scale slope stability research project at the Kimbley Pit near Ely, Nevada. The west wall of the Kimbley Pit was mined from an over-all slope angle of 45° to an over-all slope angle of 57° and the pit was deepened nearly 50 feet. Mining was begun February 10, 1966, and completed October 30, 1966. Approximately 2.55 million tons of ore and waste were mined. The project was designed and carried out to learn more about the behavior of a pit wall as its slope angle is steepened and to obtain a possible insight into engineering parameters for use in design of future slopes. Data from this project are presented as obtained from (1) instruments installed in two adits for deformation and displacement measurements, (2) a subsidence network installed on the surface above the steepened wall, (3) pre- and post-mining observations of stress in rock, (4) sonic-velocity measurements, and (5) seismic and microseismic investigations. Changes occurred in measured quantities as the slope was steepened but stopped when mining was completed. Agreement was noted between the measured changes and predicted changes obtained from calculations using the finite element technique. Subsidence surveys and microseismic studies show the steepened pit wall to be stable.

Jan 1, 1968

By Thomas C. Shrake

The Lomas Bayas copper property is located93 km (58 miles) east of Antofagasta, Region II, Chile (Fig. 1). The deposit was discovered in 1880. The deposit produced intermittently until 1992. Production at Lomas Bayas took place in high-grade veins and breccias mined underground. During 1991, Empresa Minera Mantos Blancos SA (EMMB) optioned the property from Compania Doña Ada SA. Doña Ada maintained the right to continue mining the ores by open-pit and block-caving methods and hauling the ore to its plant located60 km (37 miles) to the north. EMMB conducted exploration and column test programs. On May 9, 1994, Compania Minera Gibraltar Ltda.(CMGL) signed a purchase option agreement to acquire the Lomas Bayas property. CMGL conducted 8,612 m(9,490 ft) of reverse-circulation drilling, 2,028 m (6,650ft) of diamond drilling, a series of metallurgical tests and geologic mapping. The company then decided to exercise its purchase option.

Jan 1, 1996

By D. K. DeForest

The olfactory system (sense of smell) is crucial to the ability of fish to avoid predators, recognize kin, and synchronize reproduction (Baldwin et al. 2003). Copper (Cu) has been shown to impair olfaction in juvenile freshwater life stages of salmonids (including Pacific salmon and trout) in some laboratory experiments; and in the United States, public concerns have been expressed that current regulatory criteria for Cu in fresh water are not adequately protective of olfactory function in salmonids (e.g., OSU 2007; Pearson 2007). These concerns have largely been raised because some Cu concentrations that have caused olfactory impairment in salmonids in the laboratory are less than Cu concentrations that have been shown to reduce salmonid survival, growth, or reproduction (the effects endpoints that are typically considered in deriving ambient water quality criteria). However, two important and interrelated points that must be considered: (1) freshwater Cu criteria are "driven" by the sensitivities of several invertebrate species that are more sensitive than the olfactory impairment threshold in salmonids when (2) the influence of water chemistry on Cu bioavailability is properly considered in deriving Cu criteria. Bioavailability refers to the ability of various chemical forms of Cu to interact with receptors on the surface(s) of organisms and thus directly cause toxicity or uptake by the organisms. The toxicity of Cu and other metals to aquatic organisms is a function of water chemistry. For example, acute Cu toxicity in fresh water generally decreases as pH, water hardness (Ca2+ and Mg2+), alkalinity, and dissolved organic carbon (DOC) concentrations increase (Meyer et al. 2007). The U.S. Environmental Protection Agency (USEPA) has recommended hardness-based freshwater aquatic life criteria for Cu and other metals since the 1980s (e.g., USEPA 1985); and hardness-based metals criteria decrease (i.e., become more restrictive) as water hardness decreases. More recently, the USEPA has recommended freshwater aquatic life criteria for Cu based on the biotic ligand model (BLM; USEPA 2007), which accounts for the influence of multiple water chemistry parameters, including DOC, pH, alkalinity, Ca2+, Mg2+, and several other cations and anions. The BLM-based Cu criteria generally decrease as DOC concentration, pH, alkalinity, and water hardness decrease. Because DOC has a stronger influence on Cu bioavailability than water hardness, hardness-based and BLM-based Cu criteria can differ considerably. For example, in water that has low DOC and high hardness, the hardness-based Cu criterion would be relatively high (because it is driven by the high hardness) but the BLM-based Cu criterion would be relatively low (because it is driven by the low DOC). Thus, any evaluation of the protectiveness of Cu criteria against a given effect, such as olfactory impairment, must properly account for the chemistry of the exposure water. Meyer et al. (2013) compiled data on Cu-induced olfactory impairment and olfactory-induced behavioral effects from tests in which BLM parameters were measured. They demonstrated that the USEPA's BLM-based freshwater life criteria for Cu are protective against olfactory impairment, because it adequately accounts for water chemistry (whereas the USEPA's hardness-based Cu criteria are not consistently protective). Olfactory impairment by Cu is now receiving increased attention in Canada and Europe (e.g., Wall 2013; Stang 2013). Accordingly, in this paper we have expanded the analysis of Meyer et al. (2013) to consider copper guidelines from various other countries and whether these guidelines are protective against olfactory impairment.

Feb 23, 2014

By Kim Appleby

Epithermal gold-silver (lead-zinc-copper-manganese) mineralization on Misima Island is confined to steep and reactivated flat-lying normal faults in the upper plate of a major, shallowly dipping detachment fault. The hangingwall comprises an Eocene metavolcano-sedimentary sequence that has been extensively intruded byMiocene calc-alkaline granodiorite. It is unconformably overlain by Pliocene sedimentary and volcanic rocks. High-pressure amphibolite facies rocks dominate the footwall and have many characteristics of a metamorphic core complex. Mafic-alkalic lamprophyre dike swarms intrude the hangingwall and footwall sequences. Previous workers attributed the gold-silver mineralization on Misima to the intrusion of the porphyritic granodiorite (Williamson, 1984). This has been proposed for many tertiary gold deposits of the southwest Pacific(Sillitoe, 1989; Leach and Corbett, 1994).

Jan 1, 1996

By Jan Wolf

The iron ore industry presently utilizes two types of de-posits. The first are the high grade deposits generally located in remote areas and, secondly, the low grade de-posits which are normally found nearer to the steel-making centers. The high grade deposits produce a direct shipping ore which has an iron content which may be close to the maxi-mum 70% of Fe. These deposits have reserves which are ex-pressed in billions of tons. The ore needs little or no up-grading and where this is performed is restricted to ore washing. With the large demand for iron ore pellets, plus a national drive to perform as much of the upgrading as possible in the native country, there is a trend to erecting pellet plants at the mine location~ Large iron ore suppliers such as Australia, Brazil, Venezuela and Liberia already have pellet plants in operation, and there are new plants projected or expansion projects under study. The low grade ores are mined at locations closer to steel mills such as in Minnesota, Michigan and Canada. These low grade ores require methods of beneficiation to obtain a commercially accept-able product with the modern beneficiation techniques it is no~, possible to produce iron ore pellets of 68% Fe and 4.5% silica from ores containing as low as 26% Fe. Figure 1 gives a general picture of the types of iron ores and their beneficiation. The final product of the high grade ore is a coarse concentrate, sinter product or pellets. The final product of the low grade ores is pellets and, in some cases, coarse concentrates.

Jan 1, 1971

By Hernan Fernandez, Khalid Saif F S Al- Khayareen, Volkan Salepciler, Jacek B. Stypulkowski

Wakrah and Wukair Drainage Tunnel, WWDT is 13 km long with a 4.5 m ID sewer water tunnel about 50 to 60 m below ground surface. Integral to the project are several adits with provisions for future connections as well as four work shafts, four intermediate access shafts, ancillary hydraulic structures, and an Odor Control Facility. The shaft depths range from 50 to 60 m. The project is constructed in aggressive ground with aggressive ground water. The construction activities require years of pumping and disposal of the ground water during tunneling operations as well as construction of permanent structures in shafts. Grouting of the corrosive rock mass in corrosive groundwater for the WWDT has been described in detail.

Jun 23, 2024

By P. J. Cook

Comminution is one of the fundamentals of mineral processing, requiring large expenditures to be made on capital equipment, installation, power and maintenance. The trend toward lower grades and higher operating costs, mean mining operations are becoming increasingly marginal. The challenge is to improve and more importantly, utilize crushing and milling technologies that provide for reduced capital and operating costs whilst providing increased unit efficiencies. The Svedala Barmac Autogenous Crushing Mill presents such an opportunity by providing many of the cost savings and production increases required by its ability to produce a finer mill feed size and realize reduced energy consumption. This paper briefly describes the operation of the Svedala Barmac Autogenous Crushing Mill and reviews its benefits towards improving the efficiency of crushing and milling operations.

Jan 1, 1999

By J. M. Wempen, R. D. WEYHER, M. K. McCarter

Beam theory is a proxy for the behavior of intact, deforming roof strata above underground openings. Strong, stiff, intact strata have the ability to store significant strain energy when underground openings have large spans, as is typical of longwall operations. When strata fail, they may release some or all of this strain energy. Released energy is partitioned between fracture, thermal, and seismic energy. The tensile failure surface in simply supported beams is predicted to be free of shear stress. This prediction and the kinematic inability of crack slip during fracture make significant dissipation of energy by friction unlikely. In this study, the failure energy partitioning of Nugget Sandstone specimens is examined. Tensile fractures in specimens were induced using three-point loading tests. Elastic waves emanating from fracture events were recorded using an array of accelerometers. Accelerometers were placed within two crack lengths of the fracture surface, and the acceleration records are similar to strong motion seismic records. Spectral analysis was performed and used to develop synthetic, well-behaved, acceleration signals. Synthetic velocity signals were used to estimate radiated seismic energy generated by fracture. These estimates of radiated seismic energy demonstrate a potential means to constrain the minimum seismic partition. Fracture testing was performed on additional samples to estimate the fracture toughness of the sandstone. Synthesis of this data demonstrate a potential means to constrain a maximum seismic partition. Bounding the seismic partition for this type of fracture event could aid the detection and evaluation of seismicity emanating from longwall operations. Having better information about the location and magnitude of mining-induced seismicity within longwall overburdens could lead to better understanding of extraction sequencing and rock behavior in general. These energy estimates also support the hypothesis that dissipation of thermal energy by friction is small in bending tensile failure.

Jul 1, 2020

By E. D. Gálvez, L. A. Cisternas, R. Acosta-Flores, F. A. Lucay

Froth flotation processes are carried out in flotation cells that are grouped into banks, and these banks are interconnected, forming a flotation circuit. A literature review shows the existence of papers related to flotation circuit design based on mathematical programming. However, due to the complexity of solving the mathematical model in most of the work, it is considered that a small number of species is present in the feed to the circuit, which differs from practice. In addition, simple bank models are generally used. This paper presents a methodology for designing mineral concentration circuits that overcomes the problems mentioned. It allows the use of more suitable cell or bank models and the inclusion of several species. The methodology is based on two phases. The first phase identifies the set of optimal structures using discrete values of stage recoveries, solving several mixed integer linear programming (MILP) problems. In the second phase, the optimal design for each of the structures obtained in the previous phase is determined using a suitable model for the recovery at each cell or bank, which results in a mixed integer nonlinear programming (MINLP) model. The design of a copper concentration plant with eight species and the design of a zinc concentration plant with three species and five size fractions by species are used to validate the proposed methodology. The structure of the cells in the rougher and cleaner banks deliver structures that are novel.

THE QUARTETTE Mine near Searchlight, NV, a mine that first operated in the 1890s, could begin processing ore again by September. Jetco Enterprises Inc. plans to work through the tailings and ore close to the surface followed by plans for an openpit mine. It is one of at least three new mining efforts in the region, the Associated Press reported. Another is north of Searchlight, with yet another across the Colorado River in Arizona, east of Bullhead City. Gold mining is rare in southern Nevada. The area generally lacks the rock type that contains gold deposits. Restrictions on federal wilderness areas and protections for the desert tortoise also play a role. Gold veins in the region are generally small and erratic in length and height, Bill Durbin, a geologist and chief of southern Nevada operations for the Nevada Division of Minerals told the Associated Press. L.R. Tad Tinnell, president of Jetco Enterprises, has long eyed the mine. From 1993 to 1995, he explored and drilled on the property, which was still owned by Searchlight Mercantile.

Sep 1, 2013

By Chris Ashton, Andreas Rädle, Taner Aydogmus

"The Contract C310 is part of the current biggest infrastructure project of Europe “Crossrail” which is a major new cross-London rail link project and comprises the construction of the North Woolwich Portal, Plumstead Portal and the twin tube Thames Tunnels with a length of approximately 2.6km. Two Mix-Shield TBMs (Diameter 7.12m) were driving through differing challenging ground conditions (Thanet Sand, Gravels, Flint and Chalk) below the ground water table. The two tunnels were underpassing several listed buildings, sensitive structures, operational railway tracks with low overburden and close to existing subway tunnels in an urban environment. Several additional measures as compensation grouting, micro piles and an intensive monitoring has been carried out to ensure a safe tunnelling process. PROJECT OVERVIEW CROSSRAIL Project Crossrail Crossrail is currently the biggest infrastructure project in Europe which has been developed to serve London and the southeast of England. The project includes the construction of twin-bore tunnels on a west-east alignment under central London and the upgrading of existing National Rail lines to the east and west of central London. The new rail track, as shown in Figure 1, starting in Shenfield/ Abbey Wood in the east of London and ending in Reading / Heathrow Airport in the west of London, includes the construction of nine central area stations, providing interchange with London Underground, National Rail and London Bus services, and the upgrading or renewal of existing stations outside central London.Altogether there will be 118km of new rail tracks, including 42km of tunnels and 40 train stations. After completion in 2018, Crossrail expects 200 million passengers per year (Tauriainen, Rädle, Ingram 2013)."

Jan 1, 2016