Search Documents

By Donald A. Dahlstrom

If you have ever driven on the Autobahns of Western Germany, you are well acquainted with the "fast lane." There is no speed limit; there are only two lanes in the direction you are going, and if you choose to drive in the fast lane, you had better be prepared to drive faster than anyone or someone will tailgate you with a constant screeching horn until you move to the "slow lane." The prize for this mastery of the fast lane is some kind of a "macho" feeling and getting to your destination sooner than your competitor. This has some comparisons with today Is liquid-sol id separation. We've certainly had our moments in the fast lane but we've also had other countries forcing us into the slow lane at times. It can be very embarassing when someone almost runs over your back and then shakes a fist at you as you shakily scatter to the much slower and overcrowded lane. Because of necessity, there will be many new improvements and added requirements in the next decades into the 21st century and beyond. Those countries and industries that can maintain the pace in the fast lane will be successful while the others may well be relegated to the non-competitive lane. Before considering what will be the challenges in the future for competitive liquid-sol id separation performance, it would be wise to review progress over the past forty years in this area. The author has to admit his ancient age and believes he can act as an evaluator of these many advances. To place the beginning of the 40 years (the author predates his initiation into liquid-sol id separation by one more year), the United States was still building smelters and operating them with little or no sulphur dioxide removal , practically

Jan 1, 1989

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

We will bet you that, without prior programming within 10 minutes, we can design and simulate a 10,000 unit operation separation circuit. We will even do it at your place. We do it all the time. [ ] There are no tricks; we do it in a spreadsheet. We do it in those user friendly spreadsheet such as Quattro Pro. Spreadsheets must be user friendly. Accountants use them as do managers, business men, lawyers, doctors and salesmen. What these users seldom realize, is how powerful a mathematical tool a spreadsheet is. Among their other capabilities, spreadsheets can do a finite element analysis. That is why they are useful for accounting. That is also why they are more useful to engineers in the mineral industry. Spreadsheets are ideally suited for the engineering problems in the mineral industry. We have used then for solving problems in: a) mine ventilation; b) circuit design and optimization of dense media, flotation and sizing; c) comminution circuit design; d) shaking tables; e) Humphrey spirals; f) sluice ways and channel flow; g) lock particle and liberation problems; h) tunnel and shaft stress problems; i) cascadograph simulation; j) complex heat transfer problems; k) flow in porous media; and sheet flotation (Figure 1). Mineral industry problems presented on or with a spreadsheet are an excellent teaching instrument, problem statement and solution tools and sales devices. Spreadsheets answer easily, quickly and reliably many mineral industry engineering problems. What makes spreadsheets so useful to the mineral industry. The short answer is: they are easy to use; mineral industry problems fit the spreadsheet format. Those reasons are part of the answer. The real answer lies with the structure of the spreadsheet itself. Essentially, a spreadsheet is a "finite element analysis" form of computer software. Many mineral industry problems are readily solved by finite element analysis techniques. While some in the mineral industry may think they have never heard of finite element analysis, most use it weekly if not daily. Any profit and loss statement is essentially a finite element instrument. In fact, any array of numbers where one number is related to another may be construed as a finite element analysis product. Finite element analysis is a common daily activity. To get an appreciation of a finite element analysis, think of a monthly sales forecast for the next year. For each product and for each month, there exists a dollar figure for the forecasted amount of sales. In the forecast statement, for a given product in a given month, there is a "box" where the forecasted figure is presented. The forecast figure in that box was arrived at through some type of formula. The formula probably required some information from other neighboring boxes in the master forecast statement. Voila, one has a finite element analysis. Today the analysis would be done in a spreadsheet. A typical mineral industry problem is ventilation in an underground mine. Think of a rectangular room and pillar mining operation. Each room has air entering at a given pressure and velocity and air leaving at another pressure and velocity. During steady state, the air entering and leaving the room is determined by conditions in the adjacent rooms. One can readily model the room and pillar mine layout in a spreadsheet, and then find the flow in and out of each room at steady state. Change the flow by moving a brattice cloth or blocking off a path way and one gets a new air flow profile. Change the numbers on the spreadsheet that reflect

Jan 1, 1993

By Irwin H. Reiss

Gentlemen, the title of my paper is Surface Mining An Interim Land Use. Surface mining has become one of the major controversies of our time. This has happened in spite of the fact that all surface mining to date has involved only 6 million acres out of a total of 2300 million or approximately one-fourth of one percent of the total land area in the United States. I'm not going to dwell on whether peoples' perspectives are out of focus in light of the area involved, the energy crisis, national security, or the international balance of payments problem. While these things are all critically important, it is not the function of this paper to relate to them. Maybe the amount of attention attracted to surface mining is out of proportion to a lot of other things, but I don't feel that we should use that as a basis for procrastination. However, let me categorically state that anything that affects the surface of the earth is a form of land use --- be it an interstate highway, a power plant site, a golf course, a corn field, a strip mine, or the plot of ground on which your house is located.

Jan 1, 1974

By S. K. Nicol

Flotation, water-washing cyclones (hydrocyclones) and spiral concentrators are the three process units most commonly utilised in fine coal preparation. The results of testwork conducted on these three units will be presented and their performance and separation characteristics examined in detail. In particular, the dependence of the separation characteristics of each unit on particle size and the constraint this places on product quality (ash and sulphur levels) will be discussed. This dependence will be shown to be a critical criterion in the selection of fine coal circuits.

Jan 1, 1986

By J. K. Ross, K. O. Hoal, S. K. Appleby

Understanding ore variability is a key factor in the geometallurgical analysis of a deposit and is beneficial to process development and mine planning. Ore variability is a function of the mineralogy of a deposit, in terms of both ore and gangue minerals and their textural relationships. This study integrates optical microscopy and quantitative mineral analysis to characterize the mineralogy and texture from 13 samples from different lithologic units at the Bingham Canyon Mine. The analysis identified several parameters, such as modal mineralogy, alteration assemblages, distribution of mineral phases and alteration assemblages and microfracture and void space distribution. These parameters can have an impact on the materials’ behavior during processing. This study demonstrates that quantitative mineralogical analysis can provide detailed information for improved understanding of ore variability.

Jan 1, 2010

By I. Koliabina

In this paper, the results of mathematical modeling of casing pipes decontamination from radio-active new mineral forms directly in boreholes using hydrochloric and hydro-silicic-fluoric acids are presented. Modeling for highly and low radioactive coatings on the walls of casing pipes of Anastasievka oil-and-gas deposit was performed using GEMS software, based on the method of Gibbs energy minimization. Calculations have shown that thorianite and goethite, that are present in low-active crusts, detected in casing pipes uplifted from comparatively low depths, are well dissolved in hydrochloric acid, but radiobarite is almost insoluble. For the same acid concentrations, almost all radiobarite of high-active coatings detected in pipes uplifted from considerable depth is dissolved. To evaluate the possibility of decontamination of pipes from radiobarite of low-active coatings, modeling of crust dissolution under the action of H2SiF6 has been performed. The results have shown that for acid concentrations of more than 13 % almost all Ra and Ba are dissolved while all iron and thorium remains in goethite-thorianite solid solution. For the same acid concentration, almost all radiobarite from high-active coatings is dissolved. Therefore, no reagent allows decontamination of pipes from coatings of both types. It seems that successive or simultaneous use of both reagents (HCl and H2SiF6) in certain ratio is required. To clarify this issue, further experimental and model investigations are necessary. The issue of decontamination of casing pipes from galena that is present in high-active crusts also needs to be clarified.

Jan 1, 2005

By D. W. Scott

Ontario has a diverse industrial mineral resource base including abundant resources of structural industrial minerals such as sand and gravel, crushed stone, building stone, clay, shale, limestone and dolostone. These resources are used in the production of aggregates, brick, metallurgical stone, fillers, lime, cement and other construction materials. The majority of the operations are in deposits of Paleozoic and Quaternary age in southern Ontario, close to the major markets. Province-wide, there were over 140 million metric tonnes of aggregates produced in 1985, approximately 115 million tonnes of which was produced in southern Ontario with the remainder being largely from Crown land in northern Ontario. The structural industrial minerals account for over 80% of the value of total industrial mineral production, with the remaining 20% of the value king accounted for by the non-structural minerals being led by salt which is produced in southwestern Ontario. A host of other non-structural industrial minerals are known but production is currently restricted to calcite, gypsum, quartz, talc, nepheline syenite and by-product metallurgical sulphur products (Fig. 1). Location and Market Area Major production is in the area closest to the large markets of urbanized southern Ontario and the northeastern and north-central United States. In general, with the abundant variety and widespread resources of industrial minerals and the large population within 400 miles of most deposits, the market offers great potential. Ontario's 9 million population accounts for about 35% of the entire gross domestic product of Canada of $476.361 billion dollars in 1985. This equates to about 113 of the nation's buying power being within a 200 km (125 miles) radius of Toronto. This major concentration of industrial and economic activity has resulted in a well developed industrial minerals industry fulfilling most of the structural industrial minerals demand in Ontario, as well as a subsidiary demand in neighbouring provinces and states.

Jan 1, 1987

By G. E. Jones, G. K. Hoffman

Two Sun Juan Basin studies were completed through the USGS National Coal Availability program. The study areas are in the northwest Bisti field (Fruitland Formation) and in the eastern Standing Rock field (Menefee Formation). In the Bisti and Standing Rock areas, the original coal resource5 are estimated at 4.66 and 3.1 7 Gt (5.14 and 3.49 billion st), respectively. The Bisti coal resources are greatly reduced by the Bisti-De-Nu- Zin wilderness area, which contains an estimated 1.13 Gt (1.25 billion st) of coal. Technological restrictions remove 32.5% from Standing Rock's original resource. Available resources are 60%. 2.79 Gt (3.07 billion st), of the Bisti original resource and 65%, 2.07 Gt (2.28 billion st), of the original Standing Rock resource.

Jan 1, 2002

By Ted H. Eyde

Specialty sand and bentonite are produced in the plateau province from the Bidahochi Formation near Sanders, Apache County, Arizona. It appears that deposits of both sand and bentonite formed during the Pliocene in fluvial and lacustrine environments, respectively, along the west side of the Defiance Uplift. The bentonite is an alteration product of airborne vitric ash that fell or was washed into lakes. In the Cheto district, the individual bentonite horizons, which range from less than a foot to more than 10 feet thick, are restricted to the position of the medial volcanic member. Bentonite production began at the Allentown mine in 1924 and the Chambers mine in 1926. In 1933 strip mining of the extensive deposits in the Cheto district commenced. Production increased each year to a peak of 270,000 tons in 1957. As a result of the introduction of synthetic zeolites into petroleum refining, production declined. About 40,000 tons of bentonite are currently produced from the district each year. Bentonite is shipped out of State for processing into desiccants, thickeners, and acid-activated clay products. The specialty sand was derived from Permian sandstones and deposited by streams draining the Defiance Uplift. Although stream channels are usually restricted to the upper member of the Bidahochi, stratigraphically above the bentonite horizon, a few actually cut through the bentonite. The well-sorted sand, suitable for use as a proppant in hydraulically fractured oil and gas wells, is localized in elongate lenses along the margins of the channels. These lenses range from 5 to 50 feet in thickness and often extend thousands of feet in both width and length. The sand is about 97 percent silica, has a yield of 40 percent in the minus 20 plus 40 mesh size fraction, and has a roundness of 0.6 to 0.7 on the Krumbein scale. Production of this sand began about 1961. All of the current production, which amounts to about 40,000 tons per year, is sold in the petroleum-producing area near Farmington, New Mexico.

Jan 1, 1987

By Burt Ensley, Viatcheslav Dushenkov, Ilya Raskin, David E. Salt

Roots of many hydroponically grown terrestrial plants, including sunflower (Helianthus annuus L.) effectively remove toxic metals such as Cu+2, Cd+2, Cr+6, Ni+2, Pb+2 and Zn+2 2 from aqueous solutions. It should be possible to scale up this process such that plant roots can be used to treat large volume aqueous waste streams. It can be extrapolated from laboratory results that to reduce the Cd concentration in a waste stream, from 1 ppm to below 4 ppb, with a flow rate of 4000 L/min, would require 3500 sq. m of plant roots with a density 5 kg fresh weight per sq. m. These results suggest that the roots of hydroponically grown terrestrial plants may provide an attractive alternative to the accepted water treatment technologies.

Jan 1, 1995

By S. C. Sethi

The paper presents an analysis and discussion of the underground ventilation system at the waste Isolation Pilot Plant (WIPP), with particular emphasis on specific repository-related requirements and the gradual evolution of engineering designs relative to the WIPP Project scope. The underground facility has been constructed with three shafts. Additional studies, coupled with actual site-specific experience, have established? the need for construction of a fourth ventilation shaft to double the under-ground airflow. As a research pilot project, and the first of its type in combining mining and nuclear technologies, the WIPP Project is accumulating data and experience that may be fruitfully applied in the future designs of ventilation systems for planned commercial nuclear waste repositories.

Jan 1, 1988

By Liyan Ren, Huayang Dai, Yingcheng Li, Enquan Wang

"Three-dimensional geological modelling of coal mines is critical to the sustainable development of the mining industry. On the basis of comprehensively analyzing 3D geological modelling methods, according to the available data of mine such as geological terrain maps, cross-sections and boreholes, we present a 3D modelling method by integrating ArcGIS and 3D GeoModeller. Our motivation is to integrate the advantages of both software modules in processing, converting, integrating and transferring geological information. Special attention has been given to the data structure and processing flow. We build a 3D geological model of the Xieqiao coal mine and successfully extract the geological framework of the strata in the 11118 workface, which is consistent with that of the actual explored geology.Introduction/Background Pertinent impediments such as a lower information degree, the out-of-date information infrastructure and the low level of information management and decision-making make it critical for there to be improvements in mines. Modern exploration technologies favour the construction of digital mine. Digital mine promotes the transformation of the mining industry by integrating information, automation and intelligence to build safe, efficient, high-yield, green and sustainable mines. Three-dimensional geological modelling and visualization of mines are at the core of digital mine. Compared with traditional 2D geological data, 3D models express the various geological phenomena completely, as well as reproduce the spatial distribution of geological units quickly, allowing for the prediction of mining subsidence, better decision-making and improved geological analysis. Modelling methods such as multi-DEM, tetrahedral grid and the generalized tri-prism that are based on borehole estimation and interpolation data are used to construct 3D models of mine geology (Chen 1995,Wang et al 2003, Wu 2004a); nevertheless, these methods cannot fully use multi-source mining data, whereas multi-source integration methods can be used to build 3D models (Kaufmann and Martin 2008, Zhao et al 2009) but require user interaction in model construction and low automation in model updates. During coal production, a plethora of geological data is accumulated. The organisation of discreteinformation under dynamic conditions and the extraction of meaningful information to better service for three-dimensional modelling is a meaningful work (Wu et al 2004b)."

Jan 1, 2017

By Mark G. Aylmore, Eric J. Grimsey

Anenopyrite, both pure and in some cases associated with pyrite, was laboratory roasted either isothermally or at a constant heating rate, at temperatures mainly between 723 and 923 K and under environments of air, sulfur dioxide, oxygen and argon, as well as S02/02/H20/N2 mixtures. The mineralogy, arsenic contents and in some cases surface areas of the calcines were evaluated so as to provide an enhanced understanding particularly of the conditions under which the important transformations to pyrrhotite and magnetite occur. A thermodynamic analysis is also undertaken to rationalize the observations and provide some guidance for the operation of commercial roasters.

Jan 1, 1990

By John Mastoris, Kostis Dragasakis, Kostas Kouklidis, Shkurtë Gashi, Halil Berisha, Jenuz Bulica

Titan Group’s environmental policy and Sharrcem’s Corporate Social Responsibility (CSR) are the driving forces behind the development and implementation of a comprehensive Rehabilitation Plan at Dimce Quarry, which is the main raw material source for Sharrcem Cement Plant since the 1970’s, located in the municipality of Hani i Elezit in Kosovo. Based on an Environmental Impact Assessment Study and the approved Mining Plan and also on the principles prescribed in the Guidelines on Quarry Rehabilitation, released by the Cement Sustainability Initiative of the World Business Council for Sustainable Development (WBCSD-CSI), Sharrcem has adopted a quarry operation and rehabilitation process in line with the best practices in the mining and cement sector. This paper discusses the background for the development of the rehabilitation plan and the results of rehabilitation activities, as have been implemented over the last few years. The main objective of the progressive rehabilitation plan at Dimce Quarry is to restore the depleted pit and return it back to the original land owners for resettlement. To date approx. 3,4Ha of former mining area has been restored by backfilling and levelling of the depleted closed pit and returned back to owners, who have built their houses and turned it into a living area again. This Quarry has turned out to be a real composition and practical example of preserving and returning back the natural resources in a state compatible with the surrounding environment and with respect to the needs of the local stakeholders. The motivation for business to engage in rehabilitation activities in the first place lies in the belief that the development and implementation of a progressive and practical Quarry rehabilitation plan and restitution of the land will deliver significant environmental and social benefits that outweigh the long-term rehabilitation costs, while maintaining the company’s reputation.

Jan 1, 2017

By D. Marcus

A methodology was developed wherein. the increase in compressive strength, mineralogical changes and pore water composition were all studied simultaneously as a function, of moisturized spent shale curing time. From these results the relationship between the nature of cementation process and the composition of pore water was established. Heavy metals were entrapped in the cementing constituents and the pore water became mainly a solution of alkaline sulfates. While the specific data are applicable only to the material studied, the methodology and general conclusions are useful for evaluating the environmental factors in spent shale disposal and expected leachates composition.

Jan 1, 1984

By Earl M. Frizzell, Ronald W. Utley

Introduction For the past several years the Bureau of Mines has undertaken research to develop alternative mine material haulage systems that will improve mine productivity, reduce haulage costs, increase mineral availability, and conserve energy. One basic concept being pursued is a means for crushing primary blasted rock to a size that can be reliably and economically moved on conveyors. During 1980, mine requirements for this equipment and the capability of existing technology to satisfy these requirements were assessed. The study continued into 1981 on the basis that satisfactory equipment for this purpose needed to be developed. The objective of the 1981 program was to perform an engineering design of such a system. A mine survey and equipment development study was conducted in cooperation with the open-pit mining industry by GATX through its subsidiaries, Fuller Co. (a crusher manufacturer) and GARD Inc. (GATX's research and development center), under contract to the USBM. Results of a mine survey in the copper, iron, and molybdenum industries indicated that a universal crusher system could be developed even though details might vary from mine to mine. The crushing characteristics, including tonnages desired, were similar in all surveyed mines. Most mines had similar views about the desirability and frequency of crusher movement. The perceived need for in-nit crushing varied between copper and iron mining. The copper mines felt a greater sense of urgency for introduction of such a system, probably because typically greater vertical haulage is found in copper mines than in the iron mines. All mine personnel surveyed were interested in portable crushers and almost universally preferred gyratory-type primary crushers. They preferred large crushers, citing inherent reliability and durability, and the machine's relative freedom from clogging. Large size minimizes the number of crushers and conveyors needed. Analysis of desired crusher system characteristics (Table 1) fixed the crusher size at 1.5 x 2.3 m (60 x 89 in.). The 1.5-m (60-in.) feed-opening dimension could accept the largest material normally fed to the crusher, and the 2.3-m (894n.) head diameter could fulfill the 3.63 kt/h (4,000 stph) capacity requirement. Selected System Description The comments and analyses discussed in the contract report led to the design and refinement of a movable crusher system. This system represents the consensus of more than 100 mine workers and almost 50 construction and engineering company personnel. It is supported by more than 50 years of experience in crusher manufacturing. Although many alternatives are available for any given system, and selections are likely to be dictated by varying site conditions, the selected system is believed to be appropriate for most projected requirements. Final design would be dictated by mine operators during evaluation for approved projects. Detail design of the feed and discharge systems were not included in the study because they are mine specific. The basic system (Fig. 1) consists of a 1.5 x 2.3-m (60 x 89-in.) gyratory crusher on a structural steel frame. The frame is used as an operating platform for the crusher and as a carriage to move the crusher. The control tower includes a crusher lubrication room, a hydraulic equipment room, a switch gear room, a room for the motor control center, and a control room for operating the crusher and maintaining the equipment. The auxiliary system consists of a hydraulic rock hammer and pedestal crane with 74-t (80-st) and 14-t (15-st) hooks. Figure 1 also shows stairs, railings, and a work platform. Feed and discharge arrangements are shown on Fig. 2. The system shown is for mildclimate applications. Additional enclosure and heating would be needed for extremely cold weather conditions. Crusher A 1.5 x 2.3-m (60 x 89-in.) gyra¬tory crusher was selected for this application. This size can handle the typical throughput of 3-3.63 kt/h (3,500-4,000 stph) desired by the mines and the 1.3-m (50-in.) material to be crushed without difficulty. The crusher is the heaviest

Jan 4, 1983

By Slavoljub D. Maksimovic, Steve J. Page

The Bureau of Mines measured respirable dust emission rates from overburden drilling at a surface coal mine and the transport of this dust to downwind locations. The emission rates were estimated by using multiple gravimetric dust samplers mounted on a cross-shaped tripod located immediately downwind of the drill. The transport of this dust was measured at more distant downwind locations by a combination of respirable gravimetric sampling and integrated bag sampling of sulfur hexafluoride (SF6), which was used as a tracer gas. Two modes of sampling were used: (1) At five sampling locations arranged in a semicircle around the drill. The radius of this arc ranged from 15.85 m (52 ft) to 71.32 m (234 ft). (2) In-line sampling at downwind locations with samplers located at intervals of either 10.67 m (35 ft) or 15.24 m (50 ft) for a total distance of 76.20 m (250 ft). Samples were taken 1 .22 m to 1.52 m (4 to 5 ft) above ground level. Test results for the semicircular test arrangements showed that at any downwind location, the maximum contribution of respirable dust due specifically to the drilling operation was 42%; the average for eight tests was 13.6%. In general, there was no correlation between the downwind distance of this maximum contribution and the maximum contribution itself because of changing wind direction. Test results for the in-line arrangements indicated that the transport of the dust from the drilling operation usually decreases rapidly with distance and that, even though the drill dust may produce significant health hazards for the drill operator and drill helper (or other personnel in the immediate vicinity), the exposure of downwind personnel to drill-generated dust may not be a significant problem.

Jan 1, 1987

By T. H. Udayashankara

Soil pollution, a very serious environmental problem, has been attracting considerable attention in recent years. It is now generally recognized that land as a component of the environment deserves the same attention and protection as water and air. This recognition has arisen perhaps because of increased incidents of land pollution, the scarcity of land, and increased awareness and concern about long-term effects of land pollution on terrestrial and aquatic eco-systems and on ground water quality. Contamination of land results from a wide range of human activities, including industrial discharge process, disposal of wastewater and agriculture. The environmental impact of exploration, production and refining of crude oil is a major concern in developed and developing countries. Because of the known adverse effects of petroleum hydrocarbons on soil ecology and fertility there has been growing interest in the development of efficient technologies for the remediation of contaminated land, with a view toward making it available for further use. Crude oil is a natural product and as such is susceptible to degradation by naturally occurring micro flora. Bioremediation has become an important method for the restoration of oil-polluted environments. A bench scale study was conducted to evaluate the bioremediation technique in treating soil contaminated with transformer oil. The steps involved in this study are: (1) Preparation of contaminated soil, (2) Extraction of PAHs and PCBs from contaminated soil, (3) Treatment of contaminated soil in slurry batch reactor, and (4) Analysis of PAHs and PCBs by gas chromatography technique. The performance of reactor was assessed by measuring parameters like COD, PAHs and PCBs. The study was con-ducted for six different pulp densities ranging from 20% to 40%. The maximum removal of PAHs and PCBs was observed for 20% pulp density.

Jan 1, 2008

By Stephen G. Hardcastle

3D-CANVENT is a software package that integrates advanced computer aided design (ACRD) true 3D graphics with a mine ventilation simulator. The package runs as a Windows(tm) application to access its printer drivers environment and does not need third party CAD software. It is composed of two primary modules: DMVENT and MINEDESIGNER. DMVENT is a traditional Fortran coded Hardy-Cross iterative ventilation network solver written in 1980 with thermodynamic capabilities. This module is relatively unchanged with the traditional data input options for branch type, specified or calculated resistances, fixed flows, and fixed or variable pressure fans. MINEDESIGNER is the graphics engine that optimizes the ventilation design process. It performs the front-end transformation of input data entered in the graphical interface into the correct format for the solver. At the back-end it reconverts the historically standard tabular data output from the solver into an easily viewed graphical format. ACRD features of MINEDESIGNER are used to generate a 3D wire-frame node and branch network of the mine's ventilation system. The network can be displayed in up to 4 views orientated to XYZ planes or a 3D view. All the views have zoom, pan, slice and rotate options. The graphical interface efficiently permits data entry and editing via a mouse with pick-and-point item selection. Branches can be found or added with "search" and "join" options. Visual interpretation is enhanced by the 16 colour options for branches and numerous graphical attributes. Network locations are readily identified by alpha-numeric names for branches, junctions and fans, and also the logical numbering of junctions. The program is also readily expandable for pollutant simulation and control/monitoring applications.

Jan 1, 1995

By Joseph Fernandez, Luminita Calin

INTRODUCTION The Tunnel and Reservoir Plan (TARP), commonly known as the Deep Tunnel Project, is the daring and unique concept developed by the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) as a two-phase solution to the problem of waterway pollution and basement flooding due to sewer system backups created by the combined sewer over-flows (CSOs). Phase I, primarily for pollution control, includes the tunnels, shafts, connecting sewers and structures. These Phase I facilities intercept, during wet weather events, the CSOs within the MWRDGC TARP service area. The tunnels and shafts provide temporary storage of the CSOs for subsequent treatment at Water Reclamation Plants (WRP) before discharging into waterways. Ultimately, upon completion of Phase II, the tunnels, located from 45 m(150 ft) to 100 m (330 ft) below ground, will convey the CSOs to reservoirs for storage until WRP capacity is available. Phase II, which includes the reservoirs, pumping facilities, additional tunnels and shafts, has been planned to serve a dual purpose. The reservoirs provide storage of excess flows during wet weather events, those beyond the WRP capacity. Following the wet weather events, the stored flows can be conveyed, at controlled rates, to the WRPs for full treatment. These excess flows previously would have resulted in both overflows into the waterways and eventually backups in the local sewer systems. The storage capacity of the reservoirs also will promote the full utilization of the conveyance capacity of the tunnels and shafts, which in turn results in optimizing the conveyance capacity of the existing sewer systems. Therefore pollution control is further enhanced by allowing for capture of a greater volume of CSOs and greatly minimizing backups in the local sewer systems. The TARP project consists of four systems: O’Hare, Mainstream, Des Plaines, and Calumet, covering a total area of 971 km2 (375 mi2) and serving the City of Chicago and 51neighboring communities as shown in Figure1. With only two contracts left before completion of the Phase I tunnels, the 12.7km (7.9mi) Torrence Avenue leg, to be awarded in 1997, and the 12.4km (7.7mi) Little Calumet leg unfunded as of yet, both part of the Calumet System, the pollution control phase of the project is now 86% complete (Table 1).

Jan 1, 1997