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"A long-term mine production schedule optimization based on stochastic integer programming is presented that manages the risk due to geological variability and uncertainty while jointly considering mine profitability, truck fleet requirements and waste management. The evolution of the pit is controlled so that space within the mined-out pit is continuously provided to allow for tailings and waste rock to be replaced, thus minimizing the project’s environmental footprint. The method is applied at a taconite iron ore deposit and has a project net present value that is 16.9 percent higher than that of a conventional schedule and has a higher chance of meeting production forecasts. The stochastic schedule reduces equipment requirements by delaying waste mining and by mining selectively in order to meet plant ore feed requirements without stockpiling material, resulting in 23.7 and 26.2 percent lower mining capital and operating costs, respectively. IntroductionThe LabMag iron ore deposit is part of the Millennium Iron Range, a 210-km (130-mile) belt of taconite in northern Quebec and Labrador, Canada. LabMag has significant economic potential. It contains more than 3.3 Gt (3.6 billion st) of proven reserves at an average total iron content of 29.8 percent and is very low in impurities. However, on a project basis of 23 Mt/a (25 million stpy) of product, the required capital expenditure is estimated at more than $5 billion (SNC-Lavalin, 2014), which necessitates careful evaluation of all sources of risk. Resource estimation is one of the main sources of risk in a mining project as knowledge of the orebody is primarily based on drilling, which is often sparse because it is expensive. If the expected ore tonnages and qualities are not obtained when mining, the project cash flows are directly affected. The expected quantities and qualities of ore and waste are defined by the mine production schedule, which specifies the sequence of extraction and is dependent on the resource estimation. The goal of mine production scheduling is thus to maximize the expected profit, while also meeting all production targets and constraints, by creating an extraction schedule that is robust in the face of geological risk and has the highest chance possible of actually being realized."

Jan 10, 2017

By J. H. Fowler

Canada's gypsum industry began over two hundred years ago in the Maritime Provinces when farmers attempted to supplement their incomes by selling "land plaster" to traders bound for the United States. Rising from such humble beginnings, gypsum now contributes significantly to the economies of nine of Canada's ten provinces. Thirteen open-pit and three underground mines produced a total of 8.38 million tonnes of crude gypsum and seventeen processing plants manufactured 2.49 million tonnes of finished products in 1985. Recent economic growth in North America has resulted in steady increases in gypsum production, however, competition from foreign producers and by-product gypsum poses a growing threat to Canada's gypsum mining industry.

Jan 1, 1987

By Norman E. Lehman

INTRODUCTION The Washington Camp - Duquesne mining district is located on the east flank of the Patagonia Mountains, 98 kilometers south of Tucson and within 5 kilometers of the International border (Figure 1). Since the development of high-grade silver and copper ores by settlers in 1862, the Washington Camp - Duquesne district has yielded an estimated 450,000 metric tons of ore. The mined ores averaged 8% zinc, 2% copper, 3% lead and 124 grams of silver. REGIONAL GEOLOGY The Patagonia batholith, of Laramide age, crops out in the core of the Patagonia Mountains intruding Precambrian granite, Paleozoic sediments and Mesozoic igneous, volcanic and clastic rocks. This granodioritic batholith lies in a northwest-trending zone of Laramide plutonic rocks, which can be traced for a distance of 320 kilometers from the Nacozari district in Sonora, Mexico to the Silver Bell Mountains west of Tucson, Arizona. Several major porphyry copper systems occur within this plutonic belt including the Red Mountain deposit found at the northern end of the Patagonia Mountains. Data from more than 80 mineral deposits within the Patagonia Mountains show metal zoning symmetrical to the Patagonia granodiorite (Graybeal, 1975). Disseminated copper-molybdenum deposits occur within the batholith. Pyrometa-somatic, limestone replacement and vein deposits of copper, lead, zinc and silver occur in the wallrocks adjacent to the. granodiorite and epithermal manganese-silver deposits occur at the outer periphery of economic mineralization. GEOLOGY OF THE WASHINGTON CAMP - DUQUESNE DISTRICT Stratigraphy Nearly 900 meters of miogeosynclinal Permian and Pennsylvanian sediments are exposed in the district (Figure 2). In addition, 700 meters of older Paleozoic rocks crop out 6 kilometers north of the district. The Paleozoic rocks occur in fault contact with a sequence of Triassic-Jurassic pyroclastic and flow rocks, ranging in composition from latite to rhyolite.

Jan 1, 1977

By Lester F. Sanford

Located in the Santa Cruz Mountains eight miles north of the City of Santa Cruz and inland from the coast, lies a typical beach sand consisting of quartz and feldspar grains of the Santa Harguerita formation of the middle tertiary age, Reserves of over twenty-five million tons of this sand form the deposit presently being harvested by Pacific Cement & Aggregates, a Division of Lone Star Cement Corporation. The deposit ranges from 350 to 700 feet above sea level and varies from two percent passing a 200 mesh screen to ten percent retained on a ¼ inch screen (see Figure '#l) In 1929 the first sand plant went into operation at this site. It was replaced by a new plant in 1937. This plant continued operation until the middle of 1965 when replaced by the modern plant described in this paper.

Jan 1, 1967

The National Mining Association’s (NMA)MINExpo International ’96 is shaping up to be the organization’s largest. About 30,000 mining industry business and technical professionals are expected to descend on Las Vegas, NV Sept. 9-12 to take part in the 25 technical sessions and visit the more than 900 exhibitors who will be showing off their products and services. MINExpo will be the largest mining equipment and services exposition in the United States this year. Exhibits at MINExpo will fill the Las Vegas Convention Center, parking lots and part of the Hilton Center, located next door to the convention center. NMA estimates that this year’s show will cover more than 46,450m2 (500,000 sq ft) of exhibit space. Some of the exhibits on display will include haultrucks, hydraulic shovels and excavators, conveyors, continuous miners and tunneling machines. In addition, an array of computer equipment and software will be demonstrated. A new feature this year will be a helicopter pavilion, located in the Hilton Center. Helicopters and fixed-wing aircraft have become indispensable to many remote mining operations. NMA said that at least one full-size helicopter will be on display.

Jan 1, 1996

By R. J. Sweigard

One possible alternative for disposal of flue gas desulfurization (FGD) by-products is use as backfilling support material in highwall mine adits. The finite element method was used to analyze the variation of stresses and displacements within and around a highwall adit backfilled with FGD materials. The engineering properties of the rock material and the optimum mix proportioning of the FGD materials were obtained from laboratory tests. Finite element analyses show that, for the case in question, the roof displacement would decrease about 48 percent and the peak stress could be decreased about 58 percent. The study indicates that fairly weak FGD materials can eventually lead to stability of backfilled highwall adits.

Jan 1, 1996

"Australia’s largest rail freight network operator, the Australian Rail Track Corporation (ARTC), has selected GE Transportation’s Movement Planner solution as the key technology enabler for its Hunter Valley-focused network control optimization program.ARTC’s Newcastle-based network control, is the nerve center of Hunter Valley rail operations, where locally based train control professionals make thousands of decisions every day to safely support the annual movement of more than 24 kt/h (26,400 stph) of freight, and tens of thousands of coal, freight, grain and passenger trains each year.ARTC plans to transform its train control function by integrating and then building on Movement Planner, an advanced software solution by GE Transportation that provides real-time rail traffic planning and optimization to enable freight to move more efficiently. “The Hunter Valley rail network is one of the busiest and most complex in the country, supporting the largest coal export port in the world,” ARTC managing director and chief executive officer John Fullerton said.“As bulk freight demands grow, rail operators like ARTC and supply chains like the Hunter Valley coal network need to be creative in the way they respond so the Australian economy doesn’t miss out. That’s why we have conducted a worldwide search to find globally proven solutions that will improve our network productivity and efficiency,” Fullerton said.The Movement Planner solution considers multiple factors including train schedules, trafficcontrol systems and train movements relative to each other and then develops an optimized traffic plan for the trains throughout the network. Existing GE customers have benefited from increased visibility of network operations, higher velocity, less dwell times, and improved on-time performance across their networks."

Jan 1, 2018

By C. Patrick

Longwall face-to-face equipment transfers or moves are, for many companies, the largest single source of non-productive time in a longwall mining system. Detailed planning and resourceful thinking are paramount for economical, safe, and timely longwall moves. New equipment and innovative techniques are frequently tested in order to reduce overall move time. Determining the cost effectiveness of these ideas is difficult since the decision is influenced by many subjective factors. A project scheduling simulation model of the longwall move process was developed in order to analyze and assess the economic viability of innovative transfer methods and equipment. The model provides a project duration frequency distribution and lists of critically indexed activities and paths. It compares the monetary savings from reduced transfer time and capital costs for several innovative ideas.

Jan 1, 1994

By Rodolfo V. de la Cruz

The in-situ deformability of a highly jointed basalt rock mass was determined by two distinctly different methods: one, by the NX- borehole jack method where the displacements of opposing curved platens were related to the applied hydraulic pressures, and; two, by the modified Goodman jack method where the tangential strains on the borehole walls were related to the induced tangential stresses. The modulus obtained by the modified Goodman jack method were much higher than those obtained by the NX- borehole jack method. To explain the discrepancy, the influence of fractures and test variables such as depth, orientation, hole number and applied pressure on the calculated modulus of the rock mass were analyzed by factorial analysis and it was found that the orientations and depths of measurement has statistically significant effects. The in-situ deformability values obtained by non-linear regression analysis were also found comparable with other measurements and empirically predicted values for the basalt rock mass.

Jan 1, 1982

By Gordon M. Bell

Water has received little attention as a variable in flotation, even though it is a known fact that water hardness often has an adverse effect on purity and recovery, particularly on the flotation of non-metallic minerals. Because of this fact, process water used in some flotation plants is treated to reduce hardness to an acceptable level. In the laboratory, distilled water is usually used as the flotation medium in order to standardize conditions, whereas in flotation plants locally available water is used. At Rosiclare Works of Aluminum Company of America, Rosiclare, Illinois, where a vein-type of fluorspar deposit was being processed by flotation to make an acid-grade fluorspar concentrate until February of 1968 when the plant was closed, qualitative correlations had been observed between metallurgy and reagent consumption and the seasons of the year. The observed effects were thought to be due to seasonal variations in the quality of Ohio River water used as the flotation medium. Figure 1 shows the variations in total hardness and chloride contents of Ohio River water at Rosiclare for the period September 1964 through September 1967. During this period, the sulfate content varied from 85 to 245 ppm (as Na2SO4), the calcium from 90 to 160 ppm (as CaCO3) and the magnesium from 50 to 70 ppm (as CaCO3). The data in Figure 1 show that the total hardness and chloride contents are highest in the late summer and fall which are usually periods of low water and lowest in late winter and spring which are usually periods of high water.

Jan 1, 1970

By Arthur Miller

Most of the production of copper in the United States comes from a few large companies. Often overlooked, however, are the more numerous small mining operations, which collectively produce a significant portion of the nation's copper. The objective of this paper is to describe the operations of a small mining company - Ranchers Exploration and Development Corporation - how it views its place in this industry of giants, how it exploits the advantages offered by its relatively small size, and how it protects itself from the hazards being small introduces. Environment is, of course, a critical factor for such a company because it does not have the resources which help large companies weather periods of financial stress. Ideally, this environment is characterized by a heal thy economy, strong product demand, relatively stable prices , adequate grades and tonnages of ore commensurate with depth and over-burden, ready access to utilities, a dependable labor pool, and suitable technical "know how". When the environment is right, properties which were previously uneconomical to operate attract the attention of companies whose primary interest is a return on investment commensurate with risk over a reasonable period of time. Naturally, the amount of the investment and the duration of operation determines the size of the company which would be interested in such a venture. Such is the case with Ranchers Bluebird Mine at Miami, Arizona - a small property operated by a small company in a favorable economic environment.

Jan 1, 1967

By Paul H. Rylund

Substantial priming was a considered necessity for proper initiation of ammonium nitrate-fuel oil mixes as ANFO began to carve its niche in the mining industry in the latter fifties. Heavy priming accompanied the introduction of prills and oil to many blasting operations, large charges of high explosives were commonly used at the bottom, top and frequent intervals through-out the column. As the quality of ammonium nitrate improved and operators became more experienced, primer costs began to diminish. Increased experimentation continued with reduced primer costs a main objective. Cast primers were introduced and became accepted as an excellent companion for ANFO. Although the trend toward larger diameter boreholes became increasingly popular, emphasis on lower and lower priming costs continued. A primer was simply required to produce any type of initiation within the ANFO column to be considered adequate. Suddenly ANFO priming had digressed from excessive to marginal. Early experimental data developed at "test site" and laboratory locations indicated that ANFO had a tendency to react inefficiently in the initiation region of the column unless substantially primed. This was evidenced by the presence of unstable reaction rates detected with newly developed detonation velocity measuring equipment. These 10" order or "transient" velocities were believed to originate because of inadequate primer strength or a primer diameter to column diameter mismatch. How-

Jan 1, 1972

By W. C. Meyer

A physical model of flotation, derived from viewing froth as a kinetic species since it constitutes the carrier of ore particles, not only agrees with and is simulated by engineering math models, but is statistically verified by actual laboratory flotation data. The model couples the mechanical removal of froth using paddles with the more rapid chemical interactions taking place in the bath. It clearly shows that the kinetics of mass removal is dictated by flotation cell dimensions, paddle speed, and, more importantly, froth characteristics. Some conclusions and predictions of the model are presented.

Jan 1, 1982

By M. E. Kuchta

Surface coal mine design can be facilitated with the use of an interactive graphics personal computer program. This mineral inventory and planning program (POLY CALC) is described and its use is illustrated with a case study. The case study deals with investigating a stripping sequence and associated dragline stripping requirements.

Jan 1, 1986

Modern coal cleaning technologies have allowed coal preparation facilities to become quite efficient at removing sulfur compounds, waste rock and low grade coals from run of mine coal. Up to 50% of the raw mined coal stream may end up as refuse, particularly when the coal originates from longwall mining operations, or is high in partings, rock and impurities. The refuse materials vary from coarse materials removed by physical screening to very fine materials removed by floatation and density separation processes. Coal refuse piles are also known by a variety of other names including "waste dumps", "gob piles" and "slate dumps". The potential hazards of improperly reclaimed refuse include contamination of surface and groundwaters by acidic leachates and runoff, erosion and sedimentation into nearby watersheds, spontaneous combustion, disturbance of topsoil borrow areas, and damage from landslides should large slope failures occur. Many of these problems have been particularly acute for abandoned refuse piles, and modern regulations attempt to minimize the environmental impact of coal refuse disposal operations.

Jan 1, 1993

By J. J. Kollé

A compressed-water hydraulic pulse generator (HPG) for nonexplosive blasting of rock and con¬crete is described Energy is stored in the HPG by compressing water to ultrahigh pressure. A large, fastopening valve discharges the com¬pressed water, resulting in a high-energy impulse. The HPG can be used for small-scale bench blasting by discharging the water through a nozzle that is closely fitted into a borehole. A bench blasting system requires an HPG, a drill and an indexing mechanism to allow insertion of the HPG nozzle into a drilled borehole. Systems with discharge energies ranging from 40 to 250 kJ have been used to excavate hard rock, including andesite, granite and quartzite. The largest system can excavate 15 t/h (16.5 stph) of massive quartzite based on a 2-min cycle time for hole drilling. Blasting with an ultrahigh-pressure hydraulic pulse generator was demonstrated as an effective means of excavating hard massive rock under the confined conditions of a tunnel opening or underground sloping panel. Hydraulic blasting provides a continuous mechanized mining capability that is well suited for deep-level mining and urban excavation sites where explosives are prohibited

Jan 1, 1997

By Alexander Karim

This paper reviews the growth pattern in bauxite and alumina production, and primary aluminum smelting through 1980. Because the alumina and primary metal are intermediate products of the major integrated aluminum companies, it is not possible to determine their production costs. The costs indicated in this paper are order of magnitude costs based on published figures and the market price of these products. The conclusions in this paper indicate the general pattern of growth in the aluminum industry and are not meant to be a substitute for the feasibility and economic studies that are needed for individual bauxite mining, alumina refining and aluminum smelting projects.

Jan 1, 1968

By PAITIP THIRAVETYAN, KANJANA KUDPENG

The aim of this study was to investigate the influence of amino acids (glycine, aspartic acid, glutamic acid, lysine and tryptophan) and organic acids (citric, malic, tartaric, fumaric, oxalic, succinic and ascorbic acid) on gold extraction from silicate ore. Use of amino acids to extract gold was preferred compared with organic acids due to the presence of carboxylic group and amine groups in amino acids. Among the assessed amino acids, aspartic acid and glutamic acid had higher capacities to extract gold due to their structures, which lacked aromatic rings and long side chains. Organic acids could also extract gold. In particular, oxalic and succinic acids had the greatest capacity to extract gold versus the other tested organic acids. Moreover, aspartic acid had a greater capacity to extract gold from ores than the same concentration of succinic acid. We confirmed the aspartic acid and succinic acid functional groups by Fourier transform infrared spectroscopy. The findings revealed that aspartic acid had a greater capacity to extract gold than succinic acid due to the presence of both amine and carboxylic groups (succinic acid contained only a carboxylic group). The optimal gold:aspartic acid molar ratio was 1:6 and low concentrations of aspartic acid extracted 35–42%of gold from silicate ore within 15 days. This can be used as an alternative to traditional methods for extracting gold from ore; it is non-toxic to human health and environmentally friendly.

Aug 10, 2021

By D. D. Rabb

Originally, the term solution mining applied to a dissolution, washing, or "brining" of soluble salts such as halite (common table salt), potash or trona. After the mid-sixties, however, the definition has been expanded to include heap and dump leaching, in-place (in situ) leaching, removal of oil from tar sands, extraction of sulfur from deep wells by the Frasch process and the recovery of metalliferous solutions from geothermal sources. Solution mining is also known as borehole, non-shaft, or chemical mining; the extraction of soluble mineral values from a variety of ores using appropriate solvents and chemicals. Solution mining frequently involves chemical changes; for example, copper usually goes into solution as copper sulfate, gold and silver as a cyanide compound, and uranium as a sulfate or uranyl tricarbonate. The valuable constituent is removed from the solid body of the ore by mass transfer to a aqueous solution.

Jan 1, 1986

By R. J. Sweigard

Deep tillage is used widely as a Means of alleviating excessive soil compaction. There has been some concern that the voids created by deep tillage may collapse before a more natural soil structure develops, resulting in recompaction subsequent to deep tillage. A laboratory investigation was conducted to determine the feasibility of pneumatically injecting organic material into the voids during deep tillage to prevent any significant recompaction from occurring. Various amendments were injected into the soil in the laboratory using a small-scale ripping and injection system. Measurements were made of selected soil properties to evaluate the feasibility of this method.

Jan 1, 1993