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By I. Melik-Gaykazov, N. N. Melnikov, V. A. Fokin, S. P. Reshetnyak

Kola Mining Institute has been carrying out investigations of the possibility to steepen the walls of the Kovdor open pit with the design depth of 600 m. Steeping (up to 60°) wall angles is done by double height (24 and 30 m) benches with vertical slopes. One of the safety factors of mining with such walls is choosing the width of the safety berms preventing against rock falling from the slopes into the pit working area. The test on rock falling from 24 m benches has shown that vertical slopes are not more dangerous compared to the inclined(60-75°) ones.

Jan 1, 2003

By G. Barbery

A review is given of the present applications of random sets and integral geometry in fragmentation and liberation models of ores and minerals. Although attempts have ben made in the past to apply such mathematical techniques to the comminution of solids, it is shown that it would not result in major progress. In liberation modelling, it is demonstrated that the approach can lead to fruitful results. Following a recent paper by Davy (1984), a model of liberation prediction is developped, which can be calibrated far ore texture and breakage using image analyzers. The model is demonstrated for the case of a Poisson polyhedra ore texture and monodisperse fragment size. The model enables to predict the complete composite particle distribution, and is thus valuable for integration of ore breakage models with minerals separation models.

Jan 1, 1985

By C. L. Coldren

Recently there has been much discussion of the use of pipelines for the long-distance transportation of solids. Many have come to recognize the economies inherent in pipeline transportation. The widespread movement of oil and gas at astonishingly low costs - a gallon of oil moves from Montana to New York for less than that for the delivery of a postcard - has spurred others to sturdy this mode of transportation. Most interested people are aware of the inherent advantages of pipelines - continuity and reliability of operations - low manpower requirements per ton mile - moderate capital costs per ton mile - low maintenance costs per ton mile - low operating costs per ton mile.

Jan 1, 1963

By Victoria Vaccarezza, Corby Anderson

The demand for rare earth elements for everyday technology and applications has initiated much research into the extraction and recovery of these rare earth elements. An otherwise unknown group of minerals, eudialyte is a zircon silicate consisting of rare earth oxides (REO), contained in a unique mineral structure and represented by a complex chemical formula. Research into extraction and recovery of rare earth elements involves various beneficiation and hydrometallurgical techniques. The goal of beneficiation being to efficiently liberate and upgrade the REO content, followed by hydrometallurgy to extract the desired elements. This overview will discuss previous research on treating eudialyte group minerals via different mineral processing and extraction techniques.

By H. Lawrence

In 1977, the Bureau of Mines awarded a grant to the State of South Carolina to explore the possibility of using Landsat multispectral scanner (MSS) data as an aid in monitoring surface mining activities in selected counties of the State. Work had been done in Aiken County prior to the grant by Bureau of Mines and State personnel at the EROS Data Center using both the GE Image 100 and ESL IDIMS systems. The initial work on the 1-100 consisted of locating and measuring the areas of various kaolin mines. The results were excellent on location, identification, and accurate area measurements of several mines as compared with aerial photos of each mine. The effort also included locating and measuring the size of all mines (including sand and gravel) within two U.S. Geological Survey (USGS) 7 ½ min quadrangle maps. Line printer overlays using the IDIMS equipment and software resulted in the location of all known mines within an estimated error less than ±91.4m (5300 feet). Mine acreage was calculated by counting each symbol (which represented one pixel) and multiplying by 1.1 (the number of acres per pixel). Figure 1 shows a portion of one quadrangle overlay. Table I gives a comparison of acreage measured for sever- al mines from the 1-100 and IDIMS systems vs. aerial photo measurements.

Jan 1, 1979

By S. M. Carpenter

In an ever increasing ?carbon? society; management and growth will be measured by one?s carbon footprint (or output). Industries, especially mining, are under an ever increasing scrutiny of carbon, water and environmental mandates. These mandates are measured by the emissions caused by the combustion of fossil fuels. The fundamental building-block for any business, strategic or management decision must be based on an understanding of one?s ?footprint?. The scrutiny is most stringent for the commodities producers, power producers & fuel suppliers in the energy market. An overview of currently acceptable standards, application of those standards and nuances experienced in collecting the data necessary to analyze and complete a company?s carbon footprint will be presented. A lack of regulation, the fear and expectation of new and ever constraining rules, regulation and a change in the federal administration is a recipe for uncertainty in the marketplace.

Jan 1, 2010

By Stephen P. Harrison

The ventilation of coal mines has long been a major challenge for the mining industry. Prior to the 1969 Health and Safety Act, mine ventilation planning was almost entirely handled by individuals in mine operations and engineering who had extensive practical experience. Their background and expertise was sufficient to deal with existing ventilation problems and planning. A recent decline in the number of qualified individuals combined with more stringent state and federal regulations have necessitated a thorough engineering oriented approach to ventilation in mine planning design. To plan for an existing mine, a thorough ventilation survey must be conducted to determine the capabilities of the existing ventilation network. A ventilation survey also provides considerable useful data for long range planning. Essential information such as friction factors, entry resistance, and potential ventilation problem areas is gained from the survey data. With this information a comprehensive computer analysis can be conducted to evaluate alternative mine plans. This evaluation of mine plans is essential to minimize the number of shafts required while still maintaining the quality of mine ventilation. Using an existing mine as an example, this paper outlines a detailed procedure for organizing, con-ducting, and evaluating a ventilation survey. In addition, specific ventilation problem areas are isolated and alternative methods for their solution are considered. Furthermore, a long range mine plan is evaluated and the most feasible variation of the plan is selected.

Jan 1, 1980

By R. E. Thill

An ultrasonic, pulse-immersion apparatus and method are described for determining the effects of moisture on the dynamic elastic properties of rock. The method provides an alternative approach for assessing the moisture sensitivity of rocks. Ultrasonic wave velocities are continuously monitored in immersed rock samples as a function of water absorption and time up to saturation. Moisture effects on compressional wave velocity vary as a function of the type of rock and the time and amount of water absorption. Regression analyses are used to curve-fit plots of the data and to derive empirical expressions for compressional wave velocity as a function of water content for different categories of rock. Results indicate that compressional wave velocity can be used to predict both the moisture content and its effect on strength and deformational properties of rock. These results have potential for detecting or monitoring bad roof conditions in situations where the mine rock exhibits strength degradation with moisture absorption.

Jan 1, 1986

By S. K. Sahoo, S. K. Sharma, U. K. Singh, G. S. P. Singh

This research focuses on the strata control issues in a Bord and Pillar depillaring working under the influence of dead load condition of voluminous and fragmented softcover of overburden dump material. It reports the modeling of a mine working through the FLAC 2D software under the Indian geo-mining conditions. The modeling results of an actual mine working under softcover were compared with that under the intact overburden condition to assess the influence of the soft overburden over the depillaring working. The modeling work involved progressive caving of the strata and the cyclic goaf filling following the modelsimulated occurrence of main fall and periodic caving. Mohr-Coulomb Failure criteria along with a simplified strain-softening (MCSS) model was used to study the failure and caving mechanism. Salamon’s compaction model was used to simulate compaction and resultant stress recovery in the goaf material. Comparison of the model findings was done in terms of load on supports, abutment stress, and convergence, apart from the stress redistribution and failure mechanism. The load transfer mechanism of the soft overburden was also studied for an overall understanding of the strata behavior in such workings.

Jun 16, 2020

By Louis W. Towle

A brief history of the use of Ammonium Nitrate in explosives and blasting agents is given. Methods of manufacture and physical properties of the various types of Ammonium Nitrate are given with particular reference to their use in blasting agents Important properties of blasting agents discussed are sensitiveness, methods of initiation, velocities of detonation, strength, density, products of detonation, rate of pressure development, and borehole pressure.

Jan 1, 1959

By S. A. Allison, N. P. Finkelstein

After a brief consideration of the properties of zinc sulfide minerals, their flotation characteristics, and their reactions with thiol collectors, the literature on the activation of the minerals by cupric ion, their deactivation by cyanide, and their depression is reviewed in detail. The distinction between deactivation and depression is stressed. The contradictions in the published results and theories are discussed and attempts are made to resolve them. It is concluded that, whereas all aspects of the subject require further investigation, the study of depression is most likely to yield benefits in practice.

Jan 1, 1976

By P. Bevilacqua, G. Ferrara, M. C. Williams, T. P. Meloy

Tabling is an old environmentally friendly separation unit operation. This paper models shaking tables and explores the action and design of riffles on shaking tables. By reassessing riffle shape and riffle patterns, significant improvements in tabling performance appear feasible. While table sales appear at their nadir, a high-tech environmentally friendly table may have a significant market in the coming decade. Riffles on a shaking table impact particle separation. Particles are affected by riffles and their exit position on the table is dramatically changed, Riffle shape determines how much the riffle will influence a given material. Moreover, riffle patterns influence the concentration of a given material and its exit points on a table. This effect of riffle placement and design is modeled in a spreadsheet. Major performance and separation improvements may he expected by improved table design. Two physical laws of tabling have been derived. These laws aid in the design of sophisticated high-tech tables.

Jan 1, 1995

By Bern Klein, Richard W. Lawrence, Scott Frostad

Laboratory and field scale kinetic testing was conducted to evaluate scaling up of laboratory data. Two 20- tonne (field) cells were monitored for internal temperature, pH, conductivity, volume and rate of flow, and water quality. On a surface are. basis, results showed sulfide oxidation rates obtained using 50-kg cells are more sensitive to changes in aeration than those from 1-kg cells. Correcting the laboratory oxidation rates for field temperatures with a pH 7 activation energy, which is in the field drainage pH range, returned oxidation rates an order of magnitude lower than the field cell rates.

Jan 1, 2000

By J. Andrew McGlenn, Greg Emslie, Murray Gant

The Second Narrows Water Supply Tunnel will ensure system reliability in the event of a major earthquake and increase the Greater Vancouver Water District’s capacity to meet a growing population’s longterm needs. It includes a bored tunnel between two deep shafts located in North Vancouver and Burnaby, BC, Canada. The support of excavation for the 16-meter-diameter (52.5 ft) TBM launch shaft consists of 83-meter-deep (272 ft) unreinforced concrete slurry walls. This paper discusses challenges encountered during construction of the launch shaft slurry walls, namely excavation methods and slurry loss, and mitigative solutions implemented to successfully complete the shaft with minimal impact to project schedule.

Dec 1, 2022

By H. R. Hammond

The situation of The Consolidated Mining and Smelting Company of Canada Limited, or Cominco, may be somewhat unique in that the Company is not only a manufacturer of ammonium nitrate, but as a mining company is a major user of its own product. This situation has resulted in highly successful application of ammonium nitrate-oil explosives. Several noteworthy techniques have been developed and others have been improved. Use of this material in the mining industry has led ammonium nitrate producers to adopt the term nitro-carbo-nitrate or INN for ammonium nitrate-oil blends. A small blending plant at Cominco's largest mining property, the Sullivan Mine, at Kimberley, B.C., is producing more than 80% of all the explosive used at the Sullivan, and is supplying two other Cominco mines. Application has required intensive research to determine the best forms of ammonium nitrate for use in small holes drilled for development and long-hole stoping. It has led not only to experiments to determine the best blending oil, but also to development of loading techniques to the point where NCN is being moved through loading tubes over 700 feet. It has required research into mining practices such as hole arrangement and blasting of development cuts. It has resulted in the development of a special product for secondary breaking. All this has been accompanied by the recognition of the importance of insuring safe practices at every stage.

Jan 1, 1963

By Erika Moonin, Jim Nickerson, Claudio Cimiotti, Roberto Bono

"In response to the severe drought on the Colorado River basin and in order to preserve existing water capacity to the Las Vegas Valley, the Southern Nevada Water Authority contracted a new deep-water intake (Intake No. 3) located in Lake Mead. The current project (Contract No. 070F-01-C1) includes 5 km (3 miles) of tunnel with very difficult geological conditions and a 200- m (650-ft) deep shaft and marine works. This paper will present the current status of the design-build contract being constructed by Vegas Tunnel Constructors and the challenges and problems faced and the innovative solutions developed to handle the difficult conditions encountered during tunneling with up to 15 bars of pressure.ProjectbackgroundThe Las Vegas Valley receives the majority of its water from Lake Mead, which is located approximately 30 km (20 miles) east of the Las Vegas, NV metropolitan area. Due to the severe drought that has hit the southwest region of the United States, the water level in Lake Mead has receded from its high water level of 372 m (1,221 ft) above mean sea level (amsl) to a low of 330 m (1,076 ft) amsl in June 2015. Should the lake level continue to fall, at elevation 320 m (1,050 ft) amsl, the current water intakes will not be able to draw enough water to meet the needs of the local area. The risk of losing water capacity has prompted the construction of a new deeper intake. Not only is the new Intake No. 3 situated at a lower elevation in the lake at 262 m (860 ft) amsl, the new Intake No. 3 is also located to draw better quality (Fig. 1).Project challengesThe project has had several difficult challenges to overcome:• The work consisted of a 1.2 kt (1,300 st) structure constructed on a barge and lowered 100 m (330 ft) into Lake Mead anchored with 9,200 m3 (12,200 cu yd) of tremie concrete.• The drill-and-blast starter tunnel was impacted by three inflow events, resulting in a one-year project delay.• One of the main challenges was selecting the tunnel boring machine (TBM) and excavating the tunnel with expected hydraulic head pressure of as much as 17 bar (16 bar was the highest pressure recorded during the drive), crossing faulted areas, low rock cover and the risk of tunnel instability due to direct connection with the lake.• Extensive pre-excavation grouting with a constant head pressure ranging from 12 bar to 15 bar.• Structural repair of the cutterhead in difficult hydrogeological conditions [water inflow of approx. 800 m3/hr (4,000 gpm)].• Complete repair of the cascade sealing system for the main bearing and two replacements of the pinion bearings.• The TBM approach to the intake structure."

Jan 1, 2015

By Jake Gibson

"As one of the most pressing and important political debates of this century, climate change has captured global attention and is forcing governments to take action toward decreasing greenhouse gas (GHG) and carbon emission levels below what was previously thought to be necessary. With the ever-increasing price of diesel fuel, accompanied by the popular topic of carbon taxes and greenhouse gas emissions, the mining industry is looking to industry specialists for assistance. The benefits of a no-idle policy reach far beyond carbon reduction and fuel savings, ranging from decreased maintenance to increased engine life. With products like battery-powered ac systems and diesel-fired heaters, going noidle is easier today than ever before. With both systems being manufactured to withstand the harsh environments of the mining industry, the end user will see a seamless change from conventional, inefficient belt-driven systems to future, standalone mobile equipment HVAC.The history of GHGs and climate changeIn 1896, Svante Arrhenius first claimed that the combustion of fossil fuels may eventually result in enhanced global warming, but not until 1955 did Gilbert Plass draw global attention to global warming by summarizing that adding carbon dioxide to the atmosphere would intercept infrared radiation and thus warm the earth. Then in the early 1960s, Charles Keeling developed modern technology to produce concentration curves for atmospheric CO2 (Fig.1).In 1988, the Intergovernmental Panel on Climate Change (IPCC) was founded by the United Nations after acknowledgment of a rising global annual temperature. The IPCC consists of more than 2,500 scientific and technical experts from more than 60 countries. Because climate change could not be solved by a single country, the Kyoto Protocol was negotiated in 1998, requiring all participating countries to reduce their GHG emissions by at least 5 percent from the 1990 levels. The Protocol was signed by 186 countries in 2001 (since then several countries have retreated from the agreement, including the United States). In 2002, the Bush administration announced a policy for climate change relying on domestic, voluntary actions to reduce the "greenhouse gas intensity" of the United States economy by 18 percent by 2012. The U.S. still attends the Kyoto conference of parties (COPs) but does not participate in negotiations, as it is not bound by its terms."

Jan 1, 2014

By E. M. Frizzell

Development of mobile crusher systems for surface mining, allowing extension of continuous conveyor haulage systems into the pit, is traced from its introduction to the present. Variations in configurations are reviewed, and the compelling reasons for using mobile crusher systems are explored.

Jan 1, 1983

The "Gold" chapter of my adventures did not start with a rush. On May 14, 193 1, Thayer Lindsley wired me asking if I could examine the Pioneer mine in British Columbia right away. I replied, "Yes," but I had never heard of the Pioneer and, although many others were asking about gold during the Depression, none were doing anything about it. A little later another wire asked me to meet Gen. A.D. McRae in Vancouver in a couple of days. This was the start of 20 years of intermittent examinations for Lindsley. I took the train to Seattle and the night boat to Vancouver where I met Gen. McRae and his associate Victor Spencer. McRae had been one of the Canadian leaders during World War I and, for his services, he had been made a Canadian senator, a lifetime job. Col. Spencer was proprietor of a big store in Vancouver, and almost as distinguished. A seaplane was waiting for us in the harbor, to be piloted by Major McLaren, one of the leading Canadian flyers during the war. He flew us up the long fjord of Howe Sound and then on north along the route of the provincial-owned Pacific Great Eastern Railway past jagged snow-clad peaks to the village of Shalalth on Seton Lake. A rental car run by Curley Evans, a noted British Columbia character, was waiting for us in Shalalth and it took us for 50 miles over one of the steepest and crookedest roads I had ever seen. At the end of the road the Pioneer camp was set in a deep canyon in the Coast Range. Dave Sloan, another British Columbia character, was waiting for us and he immediately took me underground, at nine in the evening, to see the Pioneer ore. The ore body was then a small one but it was running over an ounce of gold per ton. The name Dave Sloan became synonymous with Pioneer. McRae and Spencer told me the history of Sloan arid the Pioneer on the way to the mine. The rich surface ore had first been discovered about 1879. It was then far inside the almost trackless wilderness of the beautiful

Jan 1, 1976

By C. G. Clifton

The Oatman District produced approximately 2.2 x 10 6 ounces of gold and 0.8 x 10 ounces of silver between 1897 and 1942. A total of 3.8 x 10 tons of ore averaging 0.58 O/T gold and 0.17 O/T silver was extracted from eight major orebodies and a number of lesser deposits. Oatman lies at the center of a trachyte-latite-rhyolite volcanic complex which contains at least one resurgent caldera. The orebodies are typical epithermal quartz-calcite + adularia lode deposits which are very deficient in sulfur. Ore deposition has occurred within dilatant zones on faults which radiate from a common point within-the complex. Fischer-Watt Mining approached the Oatman District with an integrated exploration program utilizing four basic procedures to define the characteristics of past productive areas the results of which were applied to unexplored portions of the vein system. These procedures, listed in their order of usefulness, in defining known and prospective mineralized zones are: vein contouring, detailed alteration mapping, fluid inclusion temperature determinations, and geochemical sampling.

Jan 1, 1980