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By R. V. Typliski, G. J. Labarre

"Hudson Bay Mining and Smelting Co., Limited, Flin Flon, Manitoba, Canada, has developed a metallurgical wastewater treatment system employing two-stage lime neutralization, sludge recirculation and conventional mechanical thickening.Laboratory investigations, initiated in 1970, led to the construction of a pilot-scale minewater treatment plant, at Schist Lake Mine, in early 1971. This plant, treating 600 cubic meters/day wastewater containing 30-60 mg/l zinc, demonstrated metal extraction efficiencies of 99% under normal operating conditions.On the basis of this pilot work, a second pilot-scale treatment system was established in 1975 at the Flin Flon metallurgical plant to treat zinc refinery process waste water. Through numerous improvements, including automatic control equipment, the system has evolved to a full-scale operation capable of treating 800 cubic meters/ day wastewater containing 4-11 gm/l zinc. Treated effluent contains 0.2-20 mgll zinc. Hydroxide sludge produced returns to the metallurgical process for recovery of metals while clarified effluent discharges to waste.With the system, Hudson Bay Mining has achieved its original goal: the reduction of environmental contamination, while realizing ii return from metal recovery."

Jan 1, 1980

By J Northfield, L Neesham

The GRE46 Underground Project lies beneath the environmentally unique and culturally endowed shore of Lake Cowal. The ore body is open both along strike and at depth and is currently defined to a strike length of 1.5km and depth of 800m. The Warraga exploration decline commenced in March 2019 and represents the first stage of the Project, which is expected to underpin production at Cowal Gold Operations (CGO) for a period exceeding 10 years. Mining operations at Cowal commenced in 2005, following a period of over 20 years of exploration and permitting. In 2015 Evolution Mining (Cowal) Pty Limited (Evolution) acquired the operation from Barrick Gold Ltd (“Barrick”). Barrick had a life of mine plan that anticipated a cessation of operations in 2024 at a processing rate not exceeding 7.5 Mtpa. Evolution have grown the regional endowment considerably and have a currently approved mine life out to 2032 with a currently approved maximum processing rate of 9.8 Mtpa. This paper examines the history, current status and future path of one part of that plan, the GRE-46 Underground Project. Topics for discussion include discovery, Mineral Resource growth under different ownership philosophies, planning, permitting and commissioning of an exploration decline and bulk sampling project, and integration with the possible future mine. Environmental sensitivities affecting regulatory approvals, timeframes, technical challenges, opportunities and solutions are discussed, along with the path required to fast-track production from the existing 14Mt, 1.4Moz Mineral Resource while complying with the requirements of modern, responsible project development stewardship.

Mar 15, 2021

By E. A. Barrett

The U.S. Bureau of Mines (USBM) conducted experiments to determine if training using a latent-image, three-dimensional (3-D) slide simulation exercise improved miners' ability to recognize roof and rib hazards. The effectiveness of this innovative type of classroom training was investigated by measuring workers' performance on a hazard recognition task. The study was unique in that hazard recognition skills were assessed in the workplace using actual coal mine roof and rib hazards. Results showed that training with a latent-image, 3-D slide simulation exercise significantly improved each subject's performance on the in-mine hazard recognition task. Further, the USBM researchers concluded that transfer of learning from the classroom to the workplace occurred.

Jan 1, 2010

By Jordan Scheremeta, Sudhir Tripathi, Mahfooz Alam

Injection leaching can improve leach ore recovery by displacing retained solutions, enhancing ore wetting, and creating new flow paths for efficient solution collection. This paper presents a method to assess the feasibility of injection leaching in finer-grained, potentially contractive ores (from a geotechnical slope stability perspective) using limit-equilibrium (LE) slope stability analysis and static deformation modeling. LE models were carried out by assigning peak undrained strengths to the heap leach ore material, and modeling the excess pore pressure induced during the injection leaching process using spatial function in Slope/W. Static deformation modeling was completed using the software Fast Lagrangian Analysis of Continua (FLAC) to evaluate the potential for deformations due to the excess pore pressures induced during the injection leaching process. A constitutive model was used to represent the geomechanical behavior of the leached ore material, which enables the prediction of deformation and potential stability issues resulting from excess pore-pressure induced during injection leaching process. The two-pronged approach provides a practical method to assess geotechnical impacts and guide data-driven decisions in injection leaching operations.

Feb 22, 2026

By G. M. Brownell

THE Falcon Lake stock is a small igneous mass, 2.6 square miles in area, which has intruded a belt of older lavas and metamorphosed sediments. It is well exposed and the entire area of its outcrop is taken up with surveyed mining claims, the claim lines forming a grid which makes ideal conditions for a detailed petrographical study of the unusual variations which are found in the composition of this unit (see Figure 1). The study of this mass, which has revealed features of both scientific and economic significance, began in the summer of 1939 when trainees in a Prospectors' Training Camp, a Do-minion-Provincial youth-training project under the writer's supervision, were, detailed to map rock outcrops on various mining claims. Microscopic study of rock specimens taken on a line across this stock were made during the following winter and proved to be of such interest that a special trip was made the following summer for the purpose of gathering more data, the results of which are presented here. Location The stock is close to the southeast corner of the province of Manitoba, about three miles from the Ontario boundary. It lies between Falcon and West Hawk lakes and less than a mile south of the Trans-Canada highway. It is easily accessible by motor car, as a branch road from the highway leads to the Sunbeam Kirkland gold mine, which is within the inner core of the stock. Previous Work This area was the first in the Province to receive attention from prospectors, who entered it from the adjacent Lake of the Woods district during the days of the mining boom in the 1890's. Small occurrences of gold, copper, molybdenum, and tungsten ores were found, but to date there has been no production from the district, except for small shipments of gold ore. The regional geology has been mapped by the Manitoba Department of Mines and Natural Resources, the Falcon Lake stock being shown and recorded as of "varying composition". The more detailed work involved in preparing the accompanying map has necessitated only minor changes in the outline as previously mapped.

Jan 1, 1941

By Herty, C. H.

Present-day interest in the question of "dirty steel" has arisen primarily from the increasingly rigid specifications on various grades of steel and from the growing conviction that non-metallic inclusions are the source of many of the difficulties in meeting these specifications. The importance of inclusions has unquestionably been over-emphasized in many cases, but on the other hand many unpublished instances could be recorded where all evidence pointed to inclusions as the primary cause for the failure of steel in rolling or in service. The solution of the problem of dirty steel is not a matter of a few years. There are almost numberless types of inclusions. They segregate in steel ingots in an entirely different manner from other impurities, and, at best, only a start has been made in developing correct analytical methods for their determination. Most of the writers in the field have expressed opinions rather than given facts, and so many variables enter into the manufacture of steel that a study of plant conditions is difficult unless definite facts on certain phases of the inclusion problem are available. This statement is not intended to convey the idea that little work has been done on this problem. On the other hand, the number of investigations has been large, but in most cases too many variables have been present to allow definite conclusions to be drawn. In the body of the text, reference to previous investigations is made at suitable points. Rather than burden the reader with a lengthy review of the literature on the general subject of inclusions, reference to the particular works pertinent to the subject matter of the bulletin has been discussed. Three excellent bibliographies b on the subject have been lately published: one by the Committee on

Jan 1, 1957

By Joseph M. Pugliese

The Bureau of Mines through its contract research program recently analyzed the mining and environmental requirements in the premining stage for copper mining in the northern highland of Wisconsin. The Critical-Path-Method (CPM) was used in this research. However, a step-by-step derivation of the CPM Diagram was beyond the scope of this effort. The Bureau of Mines objective now is to show, step by step, how the original hand-computed CPM Diagram was constructed. The streamlining (restructuring) of this diagram from the original effort is also summarized. The critical path time (longest time) through the original CPM Diagram was 25.12 yr, excluding public liaison effort. This diagram showed the involvement of the regulatory agency, mining applicant and public in the premining stage. Analysis of this diagram produced a streamlined version which reduced the critical path time by nearly 7 yr. The CPM construction methodology offered here may be applied to mine planning for any mining operation.

Jan 1, 1983

By J Heyes, G A. Maddocks, R J. Stewart, G D. Corder

Mining is an international business and vital contributor to national and global economies. It depends on the trust and confidence of investors and stakeholders for its financial and operational well-being (Committee for Mineral Reserves International Reporting Standards (CRIRSCO), 2016). The Social Licence to Operate (SLTO) is an increasingly multifaceted and multistakeholder risk that can impact investment decisions. Community challenges to broader political and economic decisions have given rise to protest delaying or stopping projects or closing mines and has led to loss of life (Ernst and Young, 2016). Some governments are now giving greater powers to stakeholders to make the final decision on approving mining and metals activities (EY, 2016). With billions of dollars in project investment at stake, ongoing engagement, collaboration and effective communication with stakeholders is crucial and mutually beneficial solutions are increasingly expected (EY, 2016). It is therefore essential that the industry communicates the risks (and opportunities) associated with investment effectively and transparently in order to earn the necessary level of trust with investors and stakeholders to underpin its activities (CRIRSCO, 2016). Despite this need, investor and stakeholder trust in the sector has eroded in recent years.CITATION:Maddocks, G A, Corder, G D, Heyes, J and Stewart, R J, 2016. The social licence to operate and drivers for change – resource reporting and mine material characterisation, in Proceedings Life-of-Mine 2016 Conference, pp 183–187 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By Robert E. Schock, Eric J. Risberg

"Less than 20,000 years ago, the last of the glaciers retreated from the Chicago region. They left behind sheets of glacial clay till underlain by dense, over-consolidated till (“hardpan”) below which is the limestone bedrock, found about 100 ft (30.5 m) below street level. The most notable feature in this profile is the unusually soft clay till that has historically been called “Chicago Blue Clay.”But the founding fathers of Chicago really didn’t care about what was under the ground. They recognized the importance of the city’s location as a potential trade and transportation hub. With access to the East through the Great Lakes and access to the West through the Mississippi River system, the viability of the city was evident. Chicago’s population grew rapidly. The city continued to grow through the Civil War years, but was dealt a devastating blow in 1871 by the Great Chicago Fire, leaving the city in ruins. The Birth of the SkyscraperAfter the cleanup of the Great Fire came the first real building boom in Chicago’s history. During this era, buildings were generally founded on shallow footings bearing on sand or clay. Many multistory buildings were constructed between 1880 and 1890 on spread footings. The first tall buildings were constructed with load bearing masonry walls. These early tall buildings suffered significant settlement as the soft clay underwent consolidation.The Home Insurance Building, built in 1885, was 12-stories tall and is generally acknowledged to be the first “skyscraper” in the U.S. It was the first building constructed with an iron skeleton frame instead of load bearing masonry walls. Spread footings were used under the interior columns in an effort to better distribute the loads, but the building still experienced large settlements.Construction began for the Monadnock Building in 1891. The 17-story building was built using load bearing walls 7 ft (2.1 m) thick, supported on rail-grillage footing foundations. When completed in 1893, the Monadnock Building boasted the title “World’s Largest Office Building.” The total building settlement over the past 125 years has been measured at over 20 in (0.51 m). The engineering community in the late 19th century observed settlement, but did not yet understand the process of consolidation of the soft clay beneath the city. During this time, many of the new buildings required structural repairs during and after construction; the problem was especially acute in buildings where highrise towers joined lower podium structures."

Jan 1, 2016

By W. E. Anderson, T. M. Brady

As part of a larger study to identify factors influencing the practical operating life of wire rope used on large draglines in surface coal mining, field trips to operating surface coal mines were made during late 1975. Wire rope performance information was obtained from personnel at 13 mine sites west of the Appalachians. Seventeen pieces of equipment, utilizing bucket sizes ranging from 30 to 220 cu yd (23 to 168 m), were documented. Draglines at large US surface coal mines can be represented as 120 machines having 60-cu yd (46-m3) buckets, moving 1.8 X 109 cu yd (1.4 x 109 m3) of overburden during 6650 hours of productive availability per year. Based on the limited field study, the calculated downtime resulting from rope-related causes averages 105.6 hours per year for each typical 60-cu yd (43-m3) dragline. The total loss in production from this source alone is thereby estimated at about 25 x 106 cu yd (19 x 106 m3) annually. Although study findings did not reveal anything about dragline rope life that wasn't known or practiced by one operator or another, most operators can expect improved rope life by periodic review of their practices and by adopting one or more life-improvement measures employed at other sites. Since rope productivity was found to vary by a factor of five among the sites studied, considerable improved average performance is possible. As little as 10% overall improvement would increase national productivity by 2 million cu yd (1.5 X 106 m3) of solid overburden removal. Associated savings in rope costs would be some $2 million annually, plus a large reduction of labor-related expenses. This report outlines preliminary findings which may prove useful to many operators in extending wire rope life. Some of these modifications or adjustments in maintenance/operating practices would not require capital investment. During the field survey, no company was found which had tried cost reductions by using presocketed dump ropes, or dump rope sheaves that opened like a snatch block, so these are suggested as possible improvements requiring modest capital input. Data Acquisition During the field visits, mine operators provided rope life information about their machines. Some of the rope life data consisted of gross averages; other data was in the form of detailed records, including rope construction and manufacturer, cutoff and resocketing periods, end-for-end switching, and downtime for rope change-out. Trends of average hoist rope life and average drag rope life determined from the field study are shown in [Fig. 1] as a function of bucket size. The three lines on the graph have slopes of 1, M, and 1/4. A comparison of the data shows that hoist ropes moved about twice as much material as drag ropes prior to retirement, although more than a two-to-one scatter within each category is evident. As expected, the larger machines with the larger buckets moved more total volume of material. The four pairs of solid symbols represent those data for which detailed rope life histories are presented in subsequent figures.

Jan 1, 1980

By Frank F. Rahne

Butler Taconite, operated by the Hanna Mining Company, is an Iron ore pelletizing operation that is located on the Western end of the Mesabi Iron Range in Northeastern Minnesota. The operation mines low-grade taconite ore and through primary crushing, two stage grinding, magnetic separation, agglomerating and indurating, produces 2.6 million annual tons of high quality, 66% iron pellets. Mining and stripping is done with 13 - M100 trucks and 5 - 12 cu. yd. shovels. The operating processes in the concentrator and pellet plant are primarily con¬trolled through a centralized control room and monitored by a PDP l140 computer. During 1969 and 1970, a re-organization of the Company took place. Through this re-organization, each mine unit was analyzed and studied to determine the proper staffing of the internal departments. At this time, it was decided to continue with further detailed studies of the Maintenance Department with the intent to reduce maintenance costs. Maintenance costs at the time of the re-organization were 38.6% of the total mine operating cost. The preliminary study indicated that the Maintenance Department had a system of maintenance, as a matter of fact, it had a separate system in each sub-maintenance division and in some of the sub-divisions each foreman had a system of his own. Therefore, from the data collected, it was decided to develop one system of maintenance that could be utilized throughout the entire operation. To determine the type of system suitable to all phases of the operation, detailed time and method studies were conducted. All types of maintenance tasks performed at the operation were studied. The data collected was analyzed and the recommended improved methods were reviewed with the Maintenance Superintendent and his staff. The new improved methods that were accepted as feasible, were introduced into the system immediately.

Jan 1, 1975

By H Fletcher

Iron Ore Holdings Ltd (IOH) is an emerging junior iron ore company that is actively developing projects in the Central and Western Pilbara region of Western Australia. IOH commissioned URS Australia Pty Ltd (URS) in mid-2008 to prepare environmental assessment documents for the Phil’s Creek Project, which was rapidly moving into the development phase. This project comprised a small open cut iron ore mine that was expected to deliver approximately seven million tonnes over a five year mine life.IOH faced several challenges in the environmental assessment process for the Phil’s Creek Project. Although the Phil’s Creek Project attained approval but has now been placed on hold, it is a useful case study to discuss these challenges and how IOH addressed them. Several important lessons were learned through this process that can assist other proponents in addressing environmental challenges in a constructive and proactive manner.One major challenge faced by IOH related to the endangered northern quoll (Dasyurus hallucatus). Another challenge was the unusually high species richness of troglofauna recorded within the project area, with several species initially known only from within the proposed pit footprint.Meeting and overcoming these challenges has provided IOH with an increased understanding of the level of input required for consultation with government departments regarding environmental assessments, and this should stand the company in good stead for developing future tenements. Challenges in regards to the environmental assessment process may be faced during future developments, but IOH’s experiences to date and the lessons learned from the Phil’s Creek Project, will help pave the way for successfully overcoming them.

Jul 11, 2011

By James C. Barker

In 1981 and 1985-1986, the Bureau of Mines conducted orientation studies of marine placer platinum-group metals (PGM). PGM are derived from the Goodnews Bay ultramafic complex and magnetic surveys show that the complex extends offshore at least four mi. The present seafloor was an emergent foreland as recently as 8000 years ago. High-energy ocean processes are transporting and depositing sediment such that PGM-bearing materials are reworked and later masked by barren littoral drift. Exploration targets include 1) placers formed since present transgression began, and 2) ancient marine and drowned fluvial deposits. Additionally, there is evidence of PGM solution transport and accretion. At least minor values of PGM in Recent lag-type placers and possible submarine strands are concentrated along an offshore scarp incised through glacial deposits into the preglacial surface between Flat Cape and Red Mountain. Other Recent PGM-bearing features include Flat Cape shoal, Chagvan Bay, Salmon River delta, and modern beaches. Ancient placers include possible N-S fluvial systems 2 to 3 mi offshore, a nearshore scarp 50 ft below sea level, and strands adjacent to projected ultramafic bedrock slopes. The existance of ancient placers is dependent on depth of glacial erosion. SEM studies show PGM are principally isoferroplatinum and osmiridium, with minor sperrylite, moncheite, and platiniridium. Gold is a co-product, and concentrates comprise chromite, ilmenite, and magnetite. Beneficiation tests successfully concentrated precious metals from natural blacksand accumulations, but failed to concentrate low-grade lag gravels.

Jan 1, 2011

By Robert H. Merrill

This Bureau of Mines report summarizes the design and tests of a gage that will simultaneously measure the deformation of a borehole along three diameters 60 degrees apart; the measurements are in a single plane normal to the axis of the borehole. The inherent errors in measurement are considered together with the problems associated with the use of the gage in the relatively severe environments in and around mine openings. These problems were treated in the design and tests of the gage and the results establish that the gage can be used to satisfactorily is determine estimates of the stresses in rock.

Jan 1, 1967

By A Gray

Physical separation features in almost every mineral processing circuit. The category encompasses a broad range of techniques and technologies including hydrocyclones, gravity concentration methods (including jigs, spirals, centrifugal concentrators, tables, heavy media separators) and thickeners, all of which make use of the inherent density differences between two mediums. It is also possible to include flotation, magnetic separation, and ore sorting in the physical separation category.However, opportunities for enhanced physical separation performance can now go beyond the common practice of optimising unit operations. Improved options exist for feed preparation ahead of the physical separation stage, enabling higher performance and lower cost outcomes for physical separation flow sheets and technologies.The use of new applications in breakage technologies combined with mineral liberation analysis to optimise liberation prior to the physical separation stage provides options for preconcentration and gangue rejection as well as better separation efficiency. The use of low cost gangue rejection and preconcentration can be an intermediate step between mining and processing that allows processing of lower cut-off grades from the mine whilst delivering higher grades to the mill.Optimising flow sheets and technology performance requires detailed understanding of particle size and shape distributions as well as liberation characteristics to suit the particular separation unit, combined with knowledge of the available technologies, their capabilities and the economic impact across the whole mine cycle.CITATION:Gray, A, 2017. The role of liberation in physical separation techniques, in Proceedings MetPlant 2017, pp 147–156 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

US 4,132,635 -In the froth flotation beneficiation of low- grade siliceous iron oxide ore, an aqueous pulp of undeslimed ore is conditioned first with a reagent formed by incorporating a water-soluble polyvalent metal salt into an aqueous solution of sodium silicate and then with oleic acid or other anionic collector and optionally pine 011 or other frother. The conditioned pulp is subjected to flotation to concentrate Iron oxide values in the froth D. C. Yang, assigned to Michigan Technological University Jan 2, 1979 7 pp (209-1 66) Filed 1-1 3-77 (759,094) Drawing below.) [ ] US 4,133,038-In the froth flotation beneficiation of copper sulfide ore or other ores, an aqueous suspension of a mineral sample of uniform grain size and composition is conditioned with a strongly adsorbable collector in an amount which is a fraction of the amount sufficient to create a monomolecular layer on the mineral grains, and the conditioning continued until the entire amount of collector is adsorbed The conditioned pulp is subjected to flotation, the floated particles separated at timed intervals, and the flotation rate coefficient determined. By varying the degree of adsorption in repeated treatments, the dependence of the flotation rate coefficient on the degree of adsorption may be determined A Nieml Jan 2, 1979 10 pp (364-502) Filed 12-7-77 (858,353) Priority Finland, 5-26-75 (75/1,525) Same: British 1,533,723, dated Nov 29, 1978 Same Canadian 1,065,066, dated Oct 23, 1979 US 4,133,746System and method for maintaining substantially steady state conditions in the froth flotation beneficiation of copper ore, molybdenum ore, or other metal ores The mass flow of flotation concentrate from the cell is monitored continuously, and the rate of admission of aeration air into the pulp in the cell is varied inversely with respect to variations in the mass flow control of rougher flotation cells is accomplished with a single valve G W Dopson, assigned to Magma Copper Co Jan 9, 1979 6 pp (209-1) Filed 11- 23-76 (744,306

Jan 1, 1980

By Martin Walker, Joseph Ang, Jongwon Lee, Alvin Bayudanto, Lilian Lorincz, Morteza Khorshidi, Wenyong Rong

This paper presents a case history of liquefaction susceptibility evaluation study for a major infrastructure project in the San José area. The subsurface material of the study area consists of Holocene alluvial deposits composed of interbedded and crosscut clays and silts, sands and gravels. The simplified approach for liquefaction triggering evaluation was carried out using both CPT data and SPT data representing site’s seismic capacity and the peak ground acceleration associated with a return period of 975 years at ground surface representing seismic demands. Site-specific cyclic stress ratio (CSR) profiles as seismic demand are also estimated from one-dimensional site response analysis. The simplified approach uses empirical depth stress reduction factors (rd) based on generic shear wave velocity profiles to account for the non-rigid response of the soil profile in estimating CSR. The CSR profiles of the simplified procedure were examined by completing site response analyses using site-specific soil profiles to represent site-specific seismic demands in the liquefaction triggering evaluation. The paper concludes with a comparison and discussion of the liquefaction evaluation examining results from CPT versus SPT data, and the comparison of CSR profiles from the simplified procedure versus site-specific response analysis.

Sep 8, 2021

By Jonathan Peck, Carl Hendricks

"Global Positioning Satellite (GPS) based positioning and navigation systems have been recently developed and implemented by AQUILA Mining Systems Ltd. on blast hole drills and electric cable shovels in Canadian open pit coal and iron ore mines. These systems enable the location of the drill bit or the shovel tracks to be accurately determined in three dimensions. The position of the drill or shovel is displayed to the operator via a real-time, Moving Map Display (MMD) on an LCD-VGA screen. The MMD allows the operator to accurately navigate the drill from blast hole to blast hole or maintain a desired shovel grade or face position, with respect to displayed bench features. The maps for the MMD are downloaded from the mine office via laptop or radio link as required or as mining plans change.To obtain reliable, accurate and real-time3D positions of mobile mining equipment, proven GPS technology has to be utilized. The GPS components need to operate reliably under the severe environmental conditions that exist on board mobile mining equipment. In addition, they have to contend with varying pit geometry’s and satellite configurations, with little or no performance degradation. These issues were initially examined in December1993 during a feasibility project between AQUILA and Gregg River Resources Ltd., in relation to implementing GPS systems on blast-hole drills.To achieve certain design objectives, AQUILA Mining Systems Ltd. has developed navigation systems for cable shovels and blast-hole drills based around off-the-shelf, high precision GPS components. These systems utilize the AQUILA Advanced Monitoring Platform (AMP), to display graphically, via the MMD, shovel grade and drill position to the operator to within ±12 inches of design coordinates. Production prototypes have been installed on a Marion 301 cable shovel and a Bucyrus-Erie49-R Series III drill at the Fording River Mine in August, 1995, at the Wabush Mine on a Bucyrus Erie 190-B shovel in June, 1995, and on a GD120 drill at Gregg River Resources Ltd. in January, 1996. All these systems have undergone field trials to test system components and functionality’s under actual production conditions. This paper will discuss these GPS-based positioning and navigation systems in subsequent sections."

Jan 1, 1997

[Mr. Scott Aberle Western Energy Co POB 99 Colstrip, MT 59323-0099 Mr. Brian L. Acton Oxbow Carbon & Minerals Inc 1601 Forum Pl-#P2 West Palm Beach, FL 33401 Mr. Laine W. Adair Genwal Resources Inc POB 1420 Huntington, UT 84518-1420 Mr. Thomas D. Aderman The North American Coal Corp 14758 Preston Rd #1100 Dallas, TX 75240-7891]

Jan 1, 1998

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

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

Jun 23, 2024