|
A-F
G-P
Q-Z
|
Anglo American, Base Metal Division
Anglo American, Gold Division
Arch Mineral Corporation
BHP Billiton
Boliden Mineral
Boliden-Westmin
CMS Energy
Coeur d'Alene Mines Corporation
COGEMA Resources, Inc.
Corporación Nacional del Cobre de Chile (CODELCO)
Cyprus Mining
Denison Mining
DeBeers
Echo Bay Mines Ltd.
Falconbridge, Ltd.
Cripple Creek District, Colorado
Itasca assessed the possible hydrologic and geochemical changes that might occur in the local ground-water system and a nearby stream as a result of the proposed expansion of the Cresson Mine. The work was conducted in support of applications for a mining permit and an NPDES permit revision. Specific tasks included critical evaluation of the historical discharge from a drainage tunnel beneath the mining district, modeling geochemical reactions in the wall rock and mine effluent, and statistical assessment of low-flow conditions in the stream receiving the tunnel discharge. As a consequence of the investigation, the applicant received a permit to mine and was successful in revising the NPDES permit conditions. Black Thunder Mine, Wyoming
Itasca conducted a field and numerical modeling investigation to evaluate and subsequently improve the dewatering system at the largest surface coal mine in North America. Data from the field investigation demonstrated that mining and dewatering operations have induced extensive drawdown in the coal, but that considerable amounts of perched ground water remain in sandstones within the overburden. Using a ground-water flow model to simulate dewatering of the coal and the complex hydrostratigraphy of the overburden, Itasca redesigned the dewatering system with a new spacing and sequencing of fewer pumping wells in the coal and small diameter, passive (without pumps) drainwells to dewater the overburden. Escondida Mine, Antofagasta, Chile
Itasca conducted a hydrogeologic and numerical modeling investigation to design a dewatering system to depressurize the pit highwall at one of the largest copper mines in the world. Itasca developed a three-dimensional ground-water flow model to assess the effects of mine seepage, recharge from tailings, and several dewatering alternatives. Itasca acted as the primary geotechnical engineering consultant to Escondida in the area of slope stability assessment and design as well as general geotechnical engineering. Major projects completed included assessment of the effects of tailings disposal adjacent to the pit on the stability of the pit walls and the ultimate relocation of a plant placed in close proximity to the deepening pit. Myra Falls Operations, Vancouver Island, BC, Canada
In 1998 a major groundfall and caving occurred at Myra Falls Mine, a blasthole operation extracting a complex zinc, copper ore in very poor ground conditions at a depth of about 3000'. Itasca was contracted to assist in the mine evaluation of the mechanism for the rock mechanics problems and the re-examination of mining methods and ground support. Based on the analyses, a new mining method was suggested (overhand drift-and-fill mining), and the ground support methods were completely overhauled. The mine decided to permanently change over to this new mining method, resulting in the purchase of significant new equipment and management commitment to the results of the rock mechanics analysis. Coal-Bed Methane Operations, Powder River Basin, Wyoming
Itasca is providing technical support for permit applications for coal-bed methane development in the Powder River Basin. Activities have included conducting a baseline hydrogeologic study of all CMS properties, geochemical modeling in support of NPDES permits on fee lands, and general hydrologic consulting related to preparing Water Management Plans as part of the Application for Permit to Drill (APD) process required on federal lands. El Teniente and Andina Mines
Itasca has provided rock mechanics and mining consulting services to CODELCO's major underground mines in Chile since 1993. El Teniente and Andina Mines are two of the world's largest block caving mines. Itasca provides services in the areas of ground control, cave undercut shapes and directions, mining sequences, etc. Itasca has also performed extensive analyses on the rockbursting problems at El Teniente. Itasca has developed a three-dimensional non-linear numerical model of El Teniente Mine that is updated and used for examination of various mining and sequencing problems, and has assisted in blasting design. McClean Lake Project, Saskatchewan, Canada
Itasca is currently estimating the concentration of arsenic in tailings that will be disposed in a carefully managed tailings facility. Arsenic released from the tailings could potentially impact nearby lakes. Consequently, Itasca helped design, conduct, and evaluate experiments to assess the effect of adjusting the pH and varying the Fe/As ratio in the tailings raffinates to reduce the amount of dissolved arsenic in the tailings discharge. Statistical methods and detailed geochemical modeling were utilized to evaluate the data and to identify the mechanisms that control arsenic concentrations in the tailings. Recommendations resulting from these studies are being followed as part of an optimization program conducted at the mill to mitigate the concentration of dissolved arsenic. Orapa and Letlhakane Mines, Botswana
Itasca has performed geotechnical and slope-design assessments for the Orapa and Letlhakane diamond mines in Botswana. Here, a sedimentary sequence of interspersed weak, highly water sensitive shales and strong sandstones surround the diamond pipes. Itasca performed estimates of rock-mass strength parameters and used numerical methods to assess slope stability. Ultimate interramp slope angles were determined, as well as local bench stability. Aquarius Mine, Timmins, Ontario, Canada
Itasca conducted a hydrogeologic investigation to estimate dewatering requirements for a proposed pit with overburden consisting of very permeable glacial outwash, to predict potential effects of dewatering on trout-bearing streams and lake levels within a nearby provincial park, and to design any necessary ground-water mitigation measures. The investigation included characterization of the regional aquifer system and development of a numerical ground-water flow model. The model was used to evaluate alternative dewatering strategies (e.g., a freeze-wall to control ground-water inflow) and their costs and to predict the effects of proposed dewatering on the regional aquifer system. Strathcona Mine, Sudbury, Ontario, Canada
Strathcona is a deep (4000') cut-and-fill operation. Itasca has assisted Falconbridge in review and modification of ground support methods and mining approaches to overcome problems in control of caving ground and rockbursting in sill pillars. Itasca has developed three-dimensional numerical models of the deep copper orebody (a flat-dipping, irregular seam up to about 4200' depth) to determine the mechanism of the rockburst problems and sequencing for sill pillar extraction. |
GENCOR
General Chemical
Getchell Gold, Inc.
Hecla Mining Co.
IMC Corp.
INCO Ltd.
ISCOR
Ivanhoe Gold Company
Kinross Mining
LKAB
Lone Tree Mine
Mt. Isa Mines
Newmont Gold Company
Noranda Mining
Petrobras Mineração S.A. - Petromisa
Placer Dome
P.T. Freeport Indonesia
Creighton Mine, Sudbury, Ontario, Canada
The Creighton Mine is currently mining at depths in excess of 7500' using blasthole stoping. The mine experiences severe problems in secondary pillar hourglassing and rockbursting. In the current environment of low nickel prices, optimization of the mining methods and ground support is required. Itasca has been contracted to perform a rock-mechanics risk assessment analysis of existing and new mining methods which could reduce cost and increase production and safety. This risk assessment involves gathering existing rock mechanics data and calibrating numerical models of the pillar and stope response at depth. The model is then used to examine various mining alternatives. Thabazimbi and Sishen Mines, South Africa
Itasca has performed slope stability assessments for these iron mines in South Africa. The Thabazimbi Mine, Dunkaporte Pit, was conducting sublevel caving operations beneath the existing pit and was inducing slope stability problems in the above pit walls, causing concern that the slope would collapse into the valley below. Itasca has also conducted three-dimensional discontinuum analyses of the undermining and ultimate slope stability. Itasca conducted slope stability and pit design studies for Sishen Mine, and trained ISCOR staff in use of Itasca programs for regular slope assessments. Hollister Mine, Midas, Nevada
Itasca completed a hydrogeologic investigation to develop a ground-water supply for an open pit mine and leaching operation. The project included siting, design, and supervising construction of production wells, design and analysis of aquifer tests, analysis of the regional hydrogeologic regime based on data from mineral and water exploration drilling programs, and review of a numerical ground-water flow model used to evaluate the long-term water supply for the mine. Brunswick Mine, Bathurst, NB, Canada
The Brunswick Mine is Canada's largest underground mine, with a daily tonnage of 9400 tonnes (using blasthole mining). It is also in the final 10 years of its life. As with most late-life mines, Brunswick has developed significant ground-control problems, including ground support of development, failure and dilution of hangingwalls and seismicity and rockbursting. Currently, Itasca staff are involved in reviewing the Life-of-Mine plans aimed at optimizing extraction to maximize recoverable tonnage and minimize cost over the final years of mine life. Itasca staff act as a team member with Brunswick engineering, mine planning, and production staff in this process. Mining Operations, Irian Jaya, Indonesia
Itasca is currently conducting a multi-faceted hydrologic and hydrogeochemical investigation at P.T. Freeport Indonesia's vast surface and underground mining operations in Irian Jaya. Specific tasks have included design and implementation of underground airlift pumping tests using multi-level piezometers, supervision of shut-in pressure tests, design of a unique passive drainwell system, use of water chemistry to define water sources, supervision of flume installations, and development of a regional numerical ground-water flow model. |
Rio Tinto PLC (formerly RTZ-CRA)
Round Mountain Gold Corporation
Royal Oak Mines
Hope Brook Mine, Stephenville, Newfoundland
SASOL
Sifto
Solvay Minerals
Southern Peru Copper Company
Teck Corporation
Unité d'Exploitation Provence (France)
U.S. Gold Corporation
Vulcan Materials Company
Westminer Canada Ltd.
Open Pit Gold Mine, Round Mountain, Nevada
Itasca reviewed and evaluated geologic and hydrogeologic data to assess potential dewatering requirements as part of a feasibility study for a proposed pit expansion. The work involved: siting, design, and construction of piezometers and test wells; design and analysis of aquifer tests; development of a conceptual hydrogeologic model (including characterization of key hydrostratigraphic and structural features); and assessment of potential dewatering requirements using analytical and numerical methods. Solvay Mine, Green River, Wyoming
Itasca began acting as rock mechanics consultant to the mine, a room-and-pillar trona operation at a depth of 1600', after it experienced a major roof collapse. Activities have included analysis of the event and use of numerical models to estimate the mechanism for the event. Design and development of a high extraction mining scheme were aimed at allowing pillar crushing and controlled closure. Non-linear numerical models were calibrated against field instrumentation and observation and then used to design suitable pillar cutting strategies to effect the desired crushing behavior. Itasca has assisted in underground implementation of this method. Tonkin Springs Mine, Eureka, Nevada
Itasca conducted a hydrogeochemical investigation to predict the chemical composition of pit lakes that could potentially form in two open pits after mine closure. The work is part of a comprehensive hydrogeological, hydrogeochemical, and geotechnical investigation to permit the start-up of a bio-oxidation gold processing facility. Dolomite Quarry, Oshkosh, Wisconsin
Itasca conducted a hydrogeologic and hydrostratigraphic investigation designed to assist in delineating ore reserves at the quarry based on the depth to an artesian sandstone aquifer underlying the dolomite. Itasca installed testholes under flowing artesian conditions and conducted airlift pumping tests to obtain hydrogeologic data. Itasca has also provided considerable geotechnical design expertise for several Vulcan quarries.
|
|
AMEC (Toronto, Ontario)
Behre Dolbear & Company, Inc. (Denver, Colorado)
Golder Associates (Vancouver, British Columbia)
JBR Environmental Consultants, Inc. (Salt Lake City, Utah)
MICON International Ltd. (Toronto, Ontario)
SRK Consulting (Vancouver, British Columbia)
Watts, Griffis and McQuat Ltd. (Lakewood, Colorado)
|
CSIRO (Australia)
HDRK (Canada)
Mining Research Directorate (Canada)
CIM (Chile)
COMRO [MiningTek] (South Africa)
BEFO (Sweden)
|
|
