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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 T. J. DeMull

The business of heap leaching requires accurate forecasting of metal production from the heaps. Business forecasts typically follow a format that project periodic (monthly, quarterly, or annual) product shipments based on anticipated operating results, e. g., tons of ore placed, grade of ore, and rate of leach extraction. Since revenue and cash flow are dependent on the metal production stream, forecasts of metal production are very important for project evaluation and business planning purposes. Nevertheless, production forecasts, particularly for new heap leach projects, have been prone to errors. The present paper identifies some of the pitfalls that would be encountered in preparing production forecasts for new heap leach operations and provides a checklist of considerations to assist in preparing a forecast. Also, the paper presents a case study of copper production forecasting used for the Sanchez Project, a heap leach operation located near Safford, Arizona, that is presently under development by AZCO Mining, Inc.

Jan 1, 1995

By N. Agron-Olshina

The application of the QEM*SEM image acquisition and analysis system to the measurement of the mineral matter in coal and the materials in fly ash is described. A new sample mounting technique was developed using iodinated epoxy to provide a backscattered electron contrast between the coal, the mounting medium and the mineral matter. Several comprehensive and detailed species identification programs for silicate minerals and materials were developed to analyse the 1000 count x-ray spectra used for the measurements. Case studies are presented to demonstrate the capabilities of the new technique to distinguish different coals and fly ashes by their mineral and material composition rather than by conventional chemical analysis. Applications of the new technique are aimed at demonstrating that composition and size distributions obtained from OEM*SEM measurements can be used: 1. to characterize coal with respect to combustion problems in power stations, 2. to characterize coal for fine coal cleaning, 3. to characterize fly ashes in relation to problems such as erosion in combustion systems and the ease of precipitability in dust collection facilities, 4. to refine the classification systems used in marketing coal for pulverized fuel firing and fly ashes as a component of cement and building materials.

Jan 1, 1992

By F. F. Peng

For a given flotation system, the rate-controlling step in fine coal flotation can be the attachment of bubble to the fine coal particles. The probability of attachment depends upon the surface characteristics and the collector adsorption on the coal particle surfaces. Thus, to further improve the flotation rate and selectivity is to alter the distribution of hydrophobicity on coal particles efficiently by applying the effective means of collector dispersion. In order to enhance the combustible recovery and selectivity of fine coal flotation, and lower the amount of collector used in the fine coal flotation processes, four modes collector dispersion/addition techniques are tested. They are direct liquid addition in pulp (mechanical agitation), ultrasonic energy dispersed collector into pulp, atomized collector into pulp and gasified collector transported by air and formation of collector-air bubbles in pulp. The effect of four collector dispersion/addition methods on the floatability of -600 µ m (-30 mesh US sieve) coal samples from four ranks of coals were studied. The ultrasonic energy dispersed collector and atomized collector flotation processes enhance flotation yield and most significantly improve the kinetics of fine coal flotation. The gasified flotation process can increase the selectivity of separation and decrease the collector consumption due to starvation flotation is achieved in this process. The flotation efficiency of gasified collector process is as high as that of conventional flotation. It is because that the effect of the decrease in the combustible recovery is offset by the increase of selectivity. In addition to flotation experiments, induction times of bubble attachment to the bed of fine coal particles for four ranks of coals are measured.

Jan 1, 1992

By Charles G. Zink

Early anthracite "deep mining" methods, production, manpower. underground transportation, labor, safety and reserves are reviewed and compared to the present and to future requirements which must be met in order to economically win the fourteen million tons of untapped reserves and to keep the product competitive in the market place.

Jan 1, 1971

By K. A. Stanley, N. A. Karl, D. R. Wilburn

"This summary of international mineral exploration activities for the year 2014 draws upon information from industry sources, published literature and specialists in the U.S. Geological Survey (USGS) National Minerals Information Center. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents analyses of exploration activities performed by the mineral industry.Three types of information are reported and analyzed in this annual review of international exploration: 1) budgetary statistics expressed in U.S. current dollars provided by SNL Metals & Mining (SNL) of Charlottesville, VA; 2) regional and site-specific exploration activities that took place in 2014 as compiled by the USGS and 3) regional events that affected exploration activities including economic, social and political conditions, which were derived from published sources and discussions with USGS and industry specialists. Commodity and regional compilations are presented in this summary. Because multiple sources are used to develop these compilations, statistics may differ depending on the source and type of data that are being reported.The SNL data summarize planned company budgets for worldwide exploration activities in 2014 for 19 nonfuel mineral commodities based on company surveys. Research focused on precious metals (gold, platinum-group metals and silver), base metals (cobalt, copper, lead, molybdenum, nickel, tin and zinc), bulk commodities (iron ore, phosphate and potash), and specialty mineral commodities (diamond, lithium, niobium, rare-earth elements, tantalum and uranium). Information on uranium exploration activities was included for the first time in 2007. Data on lithium, niobium, phosphate, potash, rare-earth elements and tantalum were compiled for the first time in 2010 because of their increased significance. Since 1999, companies with exploration budgets of $100,000 and greater were included in the SNL compilations. SNL budget estimates exclude bauxite, coal and oil and gas. Exploration budget estimates for iron ore have been compiled since 2011 but reported separately. The 2014 SNL company survey is reported by SNL to cover an estimated 95 percent of the world’s nonferrous, nonfuel mineral exploration budgets. The 5 percent that is not covered includes companies that chose not to participate in the SNL survey, private companies that do not publish their budget data, and government-funded exploration activities"

Jan 1, 2014

By Y. J. Zhang

This paper presents the results of a recent study on the development of an in-situ testing method for determining the coal strength in mine pillars. The strength testing is performed in the horizontal holes drilled into the coal rib using the penetrometer. It is a hydraulically powered device that uses an indenter to press the surface of the borehole until the load reaches the failure point of coal. The pressure and the penetration of the loading pin are recorded by the data acquisition unit. The results collected from several coal mines indicate that this testing method is ideally suited for the realistic coal strength measurements. The new testing system not only improves the accuracy of pillar strength determination, but it is more cost efficient than the conventional method.

Jan 1, 1995

By Nasri Munfah

Long Island Rail Road’s (LIRR) service to New York City is limited to Penn Station on the West Side of Manhattan, which is operating at its practical capacity for the commuter railroad. This situation imposes serious considerations for future growth and limits the destination of many Long Island commuters. The East Side Access Project will provide a connection of the LIRR to the landmark Grand Central Terminal (GCT)on the East Side of Manhattan. The construction of the connection will require significant tunneling and underground work utilizing a variety of construction techniques. In Queens, the connection will require five soft ground tunnels using pressurized face tunnel boring machine. In Manhattan, the connection will require a series of rock tunnels and caverns connecting to two deep large station caverns under GCT to accommodate eight tracks with four platforms in a stacked configuration. The caverns housing train rooms are connected to the lower level of GCT where a large concourse will be provided. With a budget of $4.3 Billion, The East Side Access Project is the largest transportation project ever undertaken in New York City. This paper provides an overview of the project, discusses its environmental and the engineering challenges, and provides an insight into the design development to date.

Jan 1, 2001

By Amila Sandaruwan Ratnayake, T. Dilmi. U. Wijewardhana, H. C. S. Subasinghe

The value addition potential of ilmenite was examined using several characterization techniques. Raw ilmenite is composed of 93.65 wt.% of FeOTiO2, 3.55 wt.% of SiO2, 1.22 wt.% of Al2O3, and the remainder being other minor oxides. Ilmenite and powdered carbonized coconut shells were mixed in the weight ratio of 4:1. A separate fraction of the same mixture was added with powdered seashells in the weight ratio of 4:1:0.5. Six fractions of each mixture were distinctly milled from 1 to 6 h in a planetary ball mill. XRD spectra (broadened and diminished reflections of ilmenite) and FTIR observations (Ti―O―Cbonding) of milled samples indicate the possible incorporation of carbon into the ilmenite structure. Any clues of an occurrence of new rutile peaks were not observed in XRD spectra of milled samples. Consequently, the carbothermic reduction has not been initiated during mechanical activation. In this case, samples powdered for 6 h in a mill were isothermally annealed for 2 h under normal airflow at temperatures of 800 °C, 1000 °C, and 1200 °C, respectively. According to the X-ray diffractograms, the annealing temperatures of 1000 °C and 1200 °C exhibited almost similar trends with rutile (R), pseudobrookite (PB) and elemental iron (F), and a very few ilmenite (I) peaks. Consequently, 6 h of milling and 1000 °C annealing were concluded as the optimum conditions for the carbothermic reduction. Moreover, this study indicated seashells as a potential rate raiser for the carbothermic reduction of ilmenite at 800 °C. Therefore, this process is applicable to upgrade ilmenite into a mixture of synthetic rutile and elemental iron.

Mar 29, 2021

By B. Li

"Sepiolite is a magnesium-rich, porous, and fibrous clay mineral with broad applications. These applications take advantage of sepiolite’s high specific surface area and unique nano-sized channel structure. Over the past years, numerous materials and techniques based on the structure and property of sepiolite have been developed. This article reviewed the recent achievements in developments and applications of sepiolite in environmental protection, catalysis area, and nanocomposites. The prospectives of sepiolite applications is also discussed. INTRODUCTION Sepiolite is a magnesium-rich, porous, and fibrous clay mineral. The typical chemical formula of sepiolite is Si12Mg8O30[OH]4[OH2]4·8H2O [1]. Sepiolite has a high specific surface area and nano-sized channels because of its special structure [2]. This unusual crystal structure projected onto the [001] plane is shown in Fig.1 [3]. As it can be seen, silicon and oxygen atoms make up for the tetrahedral structure and magnesium and oxygen atoms form octahedral structure, respectively. Those tetrahedral-octahedral-tetrahedral ribbons expand boundlessly in one direction, leading to the special fibrous structure of the sepiolite. Every tetrahedral-octahedral-tetrahedral ribbon is combined to the next by an inverted Si–O–Si bond, which causes an interlaced layer with a continuous tetrahedral sheet and a discontinuous octahedral sheet. Terminal MgO at the edges of the ribbons is coordinated with two structural water molecules, which can form hydrogen bonds with zeolitic water molecules that are located in the channels running parallel to the fiber axis [3,4]. The Mg2+ ions inside the channels can be exchanged with other cations in solution. Therefore, sepiolite can be used to remove metal cations from aqueous solutions [5,6].It can be seen from Figure. 1 and Table 1 [7], the unique structure endows sepiolite with a substantial surface area and nanoscale channels. Its specific surface area reaches 320 m2/g and channel dimensions up to 3.7×10.6 Å. There are three active adsorption sites on the surface of sepiolite: one is oxygen atoms of the Si-O tetrahedron. The second is the structural water molecules paired with magnesium ions at the edges of the ribbons, which can form hydrogen bond with adsorbent. The last one is the Si-OH groups due to the breaks of the Si-O-Si bonds on the surface of Si-O tetrahedron. Thus, sepiolite has strong adsorption ability which has been widely used in environmental protection. Moreover, sepiolite has many significant features such as good mechanical and thermal stability, rheological property, porous, and easily modification, making it be a hotspot in chemical and biological researches. However, with the development of technology, broader and more advanced applications of sepiolite have been carried out in recent years. In this study, the recent achievement in sepiolite applications is summarized, the further tendency is also discussed."

Jan 1, 2018

By J. L. Huiatt

The U.S. Bureau of Mines and Great Salt Lake Minerals and Chemical Corp. developed a froth flotation process for concentrating potassium salts from Great Salt Lake solar evaporites containing about 5 percent K. The crude evaporites, which were predominately halite (NaCl) with smaller amounts of kainite (KCl.MgSO4.2.7H20) and schoenite (K2SO4MgSO4.6H20), were conditioned in a saturated brine solution, thus converting nonfloatable kainite to the floatable mineral schoenite. Schoenite was then selectively floated with a medium-molecular weight fatty acid. Continuous small-scale pilot plant testing indicated that 80 percent of the potassium could be recovered from the crude evaporites in flotation concentrates assaying about 11 percent K.

Jan 1, 1975

By D. Malhotra

The number of variables which can effect flotation of molybdenite is very large. This paper discusses the effect of two operating variables, namely, the degree of aeration and agitation, on the grade and recovery of molybdenite. A series of factorially designed flotation tests were carried out in a "Leeds Automatic Laboratory Flotation Cell." The analysis of flotation results indicate that molybdenite can be characterized into fast-floating and slow-floating components. The rates of fast-floating components, which do not create a problem in flotation, could be varied by changing agitation of airflow rates. However, the rate of slow-floating components was stable and was only a function of residence time in the float machine. The degree of aeration has a significant effect on the grade of MoS2 with only a slight effect on the recovery of MoS2. The degree of agitation has a slight effect on the grade, but does not effect the recovery of molybdenite. The implications of the results on the design of flotation cells and control and optimization of the existing circuits is subsequently discussed.

Jan 1, 1977

By E. Farrokh

CSM and NTNU models are among the most commonly used models in TBM performance evaluation. Due to increasing application of TBM in different tunneling conditions, modification became necessary for these models. Sensitivity analyses on these two models indicate that both models are very sensitive to machine characteristics. Analyses performed on CSM database for cutter load and penetration rate prediction indicate while the r-square of the CSM model is reasonably high for the predicted cutterload, the r-square value for the penetration is low. In order to increase prediction capability of CSM model for penetration rate the model was reevaluated using non-dimensional analysis and the original database of Colorado school of mines. NTNU model is evaluated using Monte Carlo simulation and regression analysis. The results of analyses indicate that the majority of the variation of the penetration in NTNU model can be explained by only three parameters. This might indicate that the effects of other factors are overshadowed and it is worthy to reevaluate NTNU model using original database and more updated statistical methods to avoid overlapping of different parameters correlations.

Feb 23, 2014

By D. R. Wilburn

This summary of international mineral exploration activities for the year 2013 draws upon information from industry sources, published literature and U.S. Geological Survey (USGS) specialists. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents analyses of exploration activities performed by the mineral industry. Three sources of information are reported and analyzed in this annual review of international exploration for the year 2013: 1) budgetary statistics expressed in U.S. nominal dollars provided by SNL Metals & Mining (SNL) of Halifax, NS, Canada (formerly Metals Economics Group (MEG); 2) regional and site-specific exploration activities that took place in 2013 as compiled by the USGS; and 3) regional events that affected exploration activities, including economic, social and political conditions, that were derived from published sources and unpublished discussions with USGS and industry specialists. Commodity and regional compilations are presented in this summary. Because multiple sources are used to develop commodity and regional compilations, reported statistics may vary depending on the source and type of data that are being reported. The SNL data summarize planned company budgets for worldwide exploration activities in 2013 for 20 nonfuel mineral commodities based on surveys returned by companies primarily focused on precious metals (gold, platinum-group metals and silver), base metals (cobalt, copper, lead, molybdenum, nickel, tin and zinc), bulk commodities (coal, iron ore, phosphate and potash), and specialty commodities (diamond, lithium, niobium, rare-earth elements, tantalum and uranium). Information on uranium exploration activities was included in the MEG overview for the first time in 2007. MEG included data on the commodities lithium, niobium, phosphate, potash, rare-earth elements and tantalum for the first time in 2010 because of the increased topical significance of these commodities. Since 1999, companies with exploration budgets of $100,000 and greater were included in the MEG and SNL compilations. SNL budget estimates exclude aluminum, coal, and oil and gas. Budget estimates for iron ore have been compiled since 2011 but reported separately. The post-1999 budget surveys by MEG and SNL cover at least 90 percent of world?s reported nonferrous, nonfuel mineral exploration budgets; the 2013 survey is reported by SNL to cover an estimated 95 percent of these budgets. The 5 percent that is not covered is accounted for by companies that chose not to participate in the SNL survey, private companies that do not publish their budget data, and government-funded exploration activities.

By Brain W. Lawrence

Sublevel stoping generally is a large-scale open stoping method. It sometimes is referred to as long-hole or blasthole stoping. This method usually is applied to strong ore bodies that require minimal support and are surrounded by strong country rock. The ore body should be fairly regular in shape and well-defined. The dip of the footwall normally should be sufficient to allow broken ore to gravitate freely, although the method has been adapted successfully to mine some of the flatter ore bodies. Sublevel stoping is not dependent on the width of the ore body. Widths of less than 6 m (20 ft), however, make the utilization of long-hole drilling techniques more difficult. The main criteria for sublevel open stoping are competent ore and stable host rock, regular ore boundaries, and a footwall dip that exceeds the angle of repose of broken ore. Basically, the method entails providing access to the ore body at various subintervals between the main haul- age levels in order to drill and blast the intervening ore. Stope drilling is carried out from drilling drifts on the sublevels, and the ore is blasted in slices towards an open face, which generally is vertical on the downholes and may be inclined towards the open face for the up holes. The blasted ore gravitates to the bottom of the stope and is collqcted through drawpoints. Fig. 1 illustrates a typical sublevel stoping mine. The method requires extensive ore body development with relatively high capital expenditures. How- ever, much of the development is in ore, and production costs are comparatively low. Productivity rates are in the 13.6 to 27.2 t (15 to 30 st)/manshift range. The drilling, blasting, and loading operations are performed independently, and equipment utilization is high. Large outputs can be obtained with few units and limited personnel. Dilution with waste rock may occur if ore boundaries are irregular or if caving occurs, but 100% of the ore within the stope usually is recovered. Pillar recovery sometimes is a problem. It is at this point that most of the waste dilution occurs. At the time data was gathered for this report (1973), the sublevel open stoping method was used by more than 21% of the metallic ore mines in the US (9 out of 42 mines producing 1088 + t/day (1200 + stpd) and provided more than 12% of the total metallic ore production from these mines. DEVELOPMENT Access to a sublevel open stope mine is gained by a slope or shaft that is normally sunk in the footwall of the ore zone, away from any possible effects from blasting or other production operations in the stoping process. Main level interval is selected and usually varies from 45.7 to 121.9 m (150 to 400 ft), depending on the vertical extent of the ore body, the number of drawpoints required to maintain output, and the eventual stope height. The main haulage drifts are located at the bottom of the stope horizon, either directly in ore or in the footwall, with access crosscuts at intervals. Raises are driven up through the ore to connect to the level above and provide access and ventilation to the sublevel drilling drifts, which are driven horizontally in the ore for the length of the stope. Depending on the drawpoint system to be used, the stope is either undercut by a raise-and-cone system, from a scram or slusher drift, or simply provided with a drilling drift from which access is made at intervals to the main haulage level. A raise driven either at the end or in the middle of the stope (if stope access is from both ends) provides a start for opening up a vertical slot across the stope to establish a free or open face for long-hole drilling and blasting. Sublevel stoping has proved to be a relatively safe and economical system.

Jan 1, 1982

By N. Kuyucak

Uranium ores leached with sulphuric acid typically have poor dewatering properties. Applicability of controlled neutralization where gypsum precipitates as crystalline particles, improving dewatering properties of material was examined. Neutralized material was then dewatered using paste thickener to increase underflow density. The objectives are to maximize water recovery due to water scarcity and to produce suitable cemented paste fill material for optimizing underground ore recovery. Work was performed on acidic slurry samples collected after leaching but before the resin-in-pulp uranium recovery. Controlled neutralization greatly reduced volume of neutralization precipitates giving higher densities and improving the dewatering (filtration) properties. As a result it would be possible to increase the water recycled to the mill. Another benefit is that sulphate in the recycled water was reduced to saturation limit minimizing scaling of process equipment. Additional test work is needed; however, Unconfined Compressive Strength results imply that controlled neutralization increases the strength of paste fill and possibly offers opportunities towards a viable backfill option.

Jan 1, 2010

By W. L. Price

I. INTRODUCTION Today, there are two conflicting trends facing the designer of the bulk material handling system. The first trend is the necessity to stockpile increasingly larger amounts of bulk material (coal, ore, stone etc.) as economically as possible. Fig. 1 illustrates such a typical large storage pile. The second trend is the increasing awareness of the ecological problems of today manifesting itself in a new concern over possible air pollution from storage pile surface particles. The conflict between these two trends can become dramatic when this bulk storage pile is located near a heavily populated area. Strong winds can easily create a severe local problem by blowing the particles from the pile surface toward residential and commercial areas, igniting a crisis in public relations. (2), (3), (4). To help define our combined subject and ecological culprit more accurately, Fig. 2 shows the commonly accepted size range of dust particles. A descrip¬tion of the present state-of-the-art of dust control for large storage piles is the intent of this paper. II. OPEN STORAGE PILE SYSTEMS - ALTERNATE CHOICES AND RELATIVE COSTS In discussing the open storage dust problem and possible solutions, one obvious question arises - what are the economics of placing large bulk storage under cover? Part or this answer will be found in Fig. 3 - an approximate unit capital cost comparison between several methods of storage. It will be noted that the cost curve(s) for the closed concrete silo storage illustrated in Fig. 4 is cheaper per ton at relatively small tonnage capacities, but as tonnage increases, the open pile storage unit cost (B) becomes more economical. Curve (T) covers the cost of open storage using the plow feeder arrangement shown in Fig. 5. A gravity draw-down pile with feeders at the base as shown in Fig. 6 represents yet another open storage choice.

Jan 1, 1972

By R. R. Klimpel

The use of chemical reagents in flotation has been studied in great detail, e.g. (1, 2, 3, 4). Important progress has been made on the understanding of surface chemistry concepts involved in flotation. However, such scientific studies are often very complex even for rather simple idealized systems. Therefore, the deve- lopment of predictive or quantitative tools for plant engineering evaluation is still in the evolutionary stages. Until further progress in fundamental work is achieved, the operating engineer is faced with semi-empirical physical testing of reagent changes on several sizes of the actual equipment under study to be confident of the economic viability of any change.

Jan 1, 1980

By William G. Wilson

In the U.S. today a number of tentative synthetic fuel plants have been sited by a number of major corporations. Each of these for a number of reasons have deferred construction. The only synthetic fuel plants under active development are those being built with the Energy Research and Development Administration (ERDA) under the authority of the Non-nuclear Energy Research and Development Act of 1974 (Public Law 93-577). Under this Act in joint sponsorship with industry, a series of coal conversion pilot and demonstration plants are being built to produce environmentally acceptable fuels from high sulfur coals. Before entering into a discussion of the factors associated with the siting of the ERDA coal conversion program, the difference between a pilot plant and a demonstration plant should be explained. The terms pilot plant and demonstration plant iridicate a size of plant rahter than technology. A pilot plant will vary from an "add-on" to an existing facility to an independent unit. Demonstration plants are a wholly independent, self contained plants, capable of independent operation to demonstrate the environmenta1, economic, and technica1 feasibility of a technology. These plants are from one-third to one-tenth the scale of a commercial operation and often described as plus 1000 tons per day of coal consumption. Their purpose is stated in the Act (Section 6, (3)(E),) "to accelerate the commercial demonstration of technologies for producing syncrude and liquid petroleum products from coal: Provided. That the Administrator shall invite and consider proposals from potential participants based upon Federal assistants and participation through guaranteed prices or purchase of the products .... " In site selection and plant design it has been suggested that special interest groups should be allowed to dictate the site and specify the design. Under the present program the industrial partner who is contributing 50 percent

Jan 1, 1977

By Dan Martz, Stuart Lipofsky, Dean Workman

"The Indianapolis Deep Rock Tunnel Connector (DRTC)—first in a vast network of storm water storage tunnels below Indiana, USA—was a wildly successful endeavor. Crews for the Shea/Kiewit JV drove a 6.2 m Robbins Main Beam TBM to world record rates. The machine achieved 124.9 m/day, 515.1 m/week, and 1,754 m/month in limestone and dolomite rock. The advance rates can be attributed to many factors including ground conditions and knowledgeable crew, but continuous conveyors are also of key importance. The novel conveyor system, manufactured by The Robbins Company, enabled continuous tunneling in a difficult layout that included two 90-degree curves and two S-curves. Spanning 11,777 m in its longest iteration, the system included nine booster drives plus a main drive. A vertical belt moved muck up the 76 m deep shaft to a radial stacker for temporary storage. The system, one of the most complex in North America and the first to operate in 90-degree curves, made swift tunneling possible. This paper will examine the world-class tunneling done at the Indianapolis DRTC and the role of continuous conveyance in reaching high advance rates. The logistics of the system will also be examined as it could apply to future tunneling projects with similarly complex layouts. INTRODUCTION The Indianapolis Deep Rock Tunnel Connector (DRTC) is the first phase of a nearly 28-mile long network of deep rock tunnels being built 76 m beneath the City of Indianapolis, Indiana by Citizens Energy Group. The Deep Rock Tunnel Connector (DRTC) Project is a 12.2 km, 5.5 m diameter tunnel constructed by S-K JV, a joint venture between J.F. Shea Construction and Kiewit Infrastructure Co. The tunnel is a $179 million project and is the first segment and southernmost portion of a deep, large diameter conveyance and storage tunnel system to provide overflow relief during wet weather events. The project is estimated to be completed in 2017 and will initially deliver 204,000 cubic meters of the planned 1 million cubic meters of CSO storage for treatment, as well as provide future connections to other tunnels in the overall system (see Figure 1)."

Jan 1, 2016