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By Ph. Vandebrouck

SUMMARY In August 1986, TRANSMANCHE LINK, a joint venture comprising the 10 companies who initially promoted the project, signed a contract with EUROTUNNEL for the design, construction and commissioning of the TRANSMANCHE fixed link for an amount of 4,5 billion dollars. On the French side, the work consists of digging three, 19km. long tunnels, of which almost 16 kms. are under the sea, up to the meeting point with the Tunnel works carried out by the British.. The tunnels are bored through chalk by 5 tunnelling machines, starting from one intermediate point at Sangatte near the coast: - Landward, they are drilled trough permeable strata of white and grey chalk. - Seaward, mainly through relatively impermeable chalk marl, but with the presence of water in faulted zones, or in grey chalk.

Jan 1, 1989

By J. J. Beresford

The primary function of a support slurry is to provide stability during excavation. Today foundation structures can be designed around the additional friction afforded by the absence of the filter cake attributable to the use of polymeric fluids as support slurries. These fluids use pseudoplastic fluid viscosity to advantage over the fragile thixotropic gel structures of bentonite. Many of today's polymeric fluids are environmentally acceptable for disposal directly to municipal sewers.

Jan 1, 1989

By T. M. Karppanen

Shotcrete is used both in mining and tunnelling for supporting rock. Both dry and wet processes are used for shotcreting, and each produces good quality concrete. Thick shotcrete layers function as a concrete arch supporting loose rock. Thin layers prevent relative movements between the blocks of rock due to the fine concrete in the cracks and joints. No progressive fallouts occur since key blocks are kept in place. Rockbolts are often used together with shotcrete in order to create an arch around the tunnel making the rock to support itself. Shotcrete is sprayed either manually or by means of mechanized equipment. The aim is to spray required the layer thickness in one pass and with a minimum amount of rebound. Sprayed layers should also be as even as possible. The tip of the nozzle should be moved in circular movements. The shotcrete should be sprayed at a right angle to the rock surface; the optimum distance from the nozzle to the application surface must be found by experiment. In a mine shotcreting forms a materials handling system which includes batching, transporting and the actual shotcreting. The equipment used vary depending on the spraying method, mining conditions and the location of the mine. Shotcreting is performed with a purpose-designed unit in most cases where operation is mechanized. The shotcreting unit consists of a spraying machine with a hose and a nozzle, an additive system, a manipulator and a mobile carrier with all the necessary controls and accessories. The key element of the unit is the shotcreting manipulator which holds and guides the nozzle as required. The manipulators currently in use are hydraulically operated, and their remote controlled booms are also often called robots. These manipulators have enabled users to increase their output capacities, to remove the operator away from unsafe areas and from the influence of dust and rebound. Furthermore, they improve the shotcrete quality and reduce shotcreting costs.

Jan 1, 1989

By J R. Brinkmann, S G. Giltner

Nearly all of the South African gold mining industry still uses fuse and igniter-cord initiation systems. Over the past 30 years numerous attempts at developing new initiation systems have not yielded a viable alternative. New initiation systems for narrow stopes are currently being developed by various concerns and the likelihood of these efforts producing feasible alternatives is greatly improved due to the recent advances in electronics technology. The greatest potential benefit of alternative initiation systems is increased production rates through improvements in accuracy and reliability of firing over that of fuse/igniter-cord. Another important feature is the capability of millisecond delay firing as this can lead to reduced stope cleaning times by way of enhanced rock throw and improved fragmentation characteristics.

Jan 1, 1989

By F. Schlosser

The extension of Montparnasse Station in Paris required the construction of supports of very high unit capacity to support a particularly rigid super-structure. The majority of the site is characterized by the existence of old limestone quarries at a depth of approximately 20 metres. These workings have been backfilled in some places, have collapsed in some places and have given rise to local subsidences in the marne layers above them. This paper addresses the steps taken by the group of companies and their consultants to evaluate the equivalent stiffnesses of the supports necessary for the design of the superstructure, and gives details of the construction techniques chosen by the foundations specialist to adapt to the particular conditions encountered on this site.

Jan 1, 1989

By R. W. Hagemeyer

By way of background. it is important to keep in mind that the information presented in this paper relates specifically to synthetically produced precipitated calcium carbonate (PCC) fillers. Natural calcium carbonate fillers manufactured by grinding limestone, marble and chalk, though having similar chemical and physical analyses to PCCs, normally contribute somewhat different performance properties in paint, paper and polymer systems. Many factors have been cited and numerous theories have been proposed for the observed differences. Particle size parameters, surface chemistry and particle morphology are the items most frequently mentioned. A discussion of this subject is beyond the scope of this paper.

Jan 1, 1989

By M. D. Dennis

Precious metal mineralization at Mt. Hamilton" Nevada is associated with a poly-metallic, garnet-pyroxene skarn system developed in middle to upper Cambrian calcareous shales, limestones and dolomites. The skarn is developed around the Cretaceous Seligman and Monte cristo calc-alkaline stocks. Gold is associated with intense retrograde alteration. Later epithermal quartz veins containing gold, silver, base-metal sulfides, and sulfosalts cross-cut skarn alteration. Westmont Mining Inc. is currently developing two mineralized zones containing a geologic resource of approximately 7.7 M.T., which averages 0.05 OPT gold and 0.5 OPT silver. The project will have an estimated mine life of seven years, with a planned annual production rate of 35,000 ounces of gold and 300,000 ounces of silver.

Jan 1, 1989

By R. Spring

Artificial intelligence, and especially expert systems, are currently receiving considerable attention. Of interest to the control engineer is the utilization of these tools for real-time process control applications. To evaluate this technology, a real-time expert control system was implemented in one of the grinding circuits at Brenda Mines Ltd. The performance of this micro computer based expert system compared satisfactorily to the proven supervisory control system currently in use. The study confirmed the expectations that expert systems have potential for real-time, supervisory control of mineral processing operations.

Jan 1, 1989

By G. Coryell, E. Brack

"Remaining competitive in today's metal markets requires that copper smelters utilize the latest technology offered in process control, data acquisition, and process optimization. State-of-the-art tools like minicomputers, personal computers, and microprocessor based controllers provide real time process information that assist in making proper adjustments to the overall control strategy of an operating plant. The database accumulated by such systems broaden process knowledge, thereby reducing costly errors and plant downtime.IntroductionThe ASARCO Hayden Plant is located approximately 80 miles southeast of Phoenix, Arizona. The plant was commissioned in 1912 for the purpose of smelting copper concentrates from the surrounding mining district. Copper was produced for many years using calcining, reverberatory smelting and copper converting techniques. With the stricter environmental controls of the 1970's, the smelter experienced substantial declines in efficiency and productivity. It became necessary to identify and install a new smelting technology to maintain the viability of the Hayden plant.In 1980, after evaluating several smelting techniques, ASARCO management selected flash smelting as developed by International Nickel Company (INCO). One hundred and thirty-two million dollars was allocated for the project and construction began in 1982. Construction was completed and the new plant came on line in November of 1983."

Jan 1, 1989

By Dight P. M, Dugan K. J

Design approaches for the artificial support of open pit walls have been reviewed and the main factors affecting support performance have been identified. An example of passive support in a potentially unstable pit wall has been used to demonstrate the importance of slope displacement as part of the support design process.

Jan 1, 1989

By B. D. Hanson

The U.S. Bureau of Mines has developed an interactive computer program which enables the user to identify the effect of cutting system changes on relative dust generation and forces for continuous miner drums. The program simultaneously evaluates machine and coal seam parameters, and those parameters which the user can control. One or more of these parameters may be changed to determine their individual or collective effect on relative dust generation and cutting forces. The program is written in the BASIC programming language. A complete program listing is included along with user instructions and sample outputs.

Jan 1, 1989

By Peck J. P, Kennedy D

Drill performance monitoring studies were recently completed at the Fording River mine, British Columbia. Microprocessor-based instrumen- tation and data analysis techniques were developed with the objective to improve short and long term mine planning. Data analysis permitted the identification of thicknesses and interfaces between soft/hard zones at depth based upon the recorded responses of the drill. Data clearly con- trast the soft coal seams and harder waste rock units based on variations in recorded drill rotary speed and torque, hydraulic downpressure, bail- ing air pressure and instantaneous rate of penetration. These parameters were monitored and recorded at 10 cm sampling intervals. Processed drill data was correlated with gamma logs, an existing means for locating coal seams and distinguishing between waste units. Current development of a pattern recognition module aims towards automated interpretation of drill data, identifying micro-and macro-geological and geomechanical rock mass characteristics. Delay between acquiring, processing and interpret- ing the drill data for practical use by mine personnel should be minimized. Integration of this technology with the mine's current main-frame based Mine Engineering Application System software will enable more accurate and timely annlication of the nrocessed drill data.

Jan 1, 1989

By Milos Krofta, Donald B. Aulenbach, James P. Van Dyke

INTRODUCTION An innovative Ø.1-MGD (378.5-m3/day) biological and phyicochemical wastewater treatment system at Hancock, Massachusetts, USA, has been treating the domestic sewage generated from the four-season Jiminy Peak timeshare resort since 1985. The influent raw sewage is collected and equalized in an equalization tank, then biologically treated by two rotating biological contactors (RBC). A portion of the RBC effluent is discharged to a secondary sedimentation tank to simulate conventional waste treatment by a conventional RBC system. For parallel treatment the remaining portion of the RBC effluent is discharged to an innovative Sandfloat (SASF-8) clarifier to simulate a two-stage biological and physicochemical treatment by RBC-Sandfloat. Both secondary sedimentation effluent and Saandfloat effluent are later combined together and discharged to a tertiary sand filter and two UV disinfection'units for final polishing. The operation and performance data of Jiminy Peak plant in the period of May 1985 to March 1988 was fully documented in the Lenox Institute technical report No. LIR/Ø3-88/292 (391 pages, March 1988). This report presents only background information and complete plant data in the period of April 1988 to January 1989. Dr. Lawrence K. Wang and Mr. James P. Van Dyke have been the Consulting Engineer and Director of Special Projects, respectively, for the Jiminy Peak Project since 1985. (Key Words) Innovative and Alternative Technology, Rotating Biological Contactor, Sandfloat, Dissolved Air Flotation, Sedimentation, Tertiary Filtration, Ultraviolet, Disinfection. BACKGROUND INFORMATION Jimmy Peak, Inc., Hancock, Massachusetts, has designed and constructed a secondary wastewater treatment system consisting of preliminary/primary treatment facilities, two rotating biological contactors, a dissolved air flotation clarifier, a secondary sedimentation clarifier, a sand filter and two ultraviolet (UV) disinfection units. Total average wastewater flow is approximately Ø.1 ) (378.5 cubic meters per day). In accordance with the Consulting Engineer's preliminary design, the total wastewater stream is initially collected and equalized by an equalization tank, and then biologically treated by rotating biological contactors (RBC). Part of the RBC effluent is diverted to a Krofta Sandfloat (SASF-8) for physicochemical clarification in order to simulate an innovative RBC-Sandfloat two-stage waste treatment system. The remaining part of the RBC effluent is diverted to a sedimentation tank for secondary clarification in order to siumulate a conventional secondary RBC-sedimentation waste treatment system for the purpose of parallel comparison. Both Sandfloat effluent and sedimentation effluent are later combined together and discharged to the subsequent sand filter and UV disinfection unit for final polishing. Figure 1 shows the flow diagram of Jiminy Peak Plant. The Massachusetts Clean Waters Act (M.G.L.c.2l,s.26-53) was amended by Chapter 246 of the Acts of 1973 to authorize the Massachusetts Department of Environmental Quality Engineering (DEQE), Division of water Pollution Control, Boston, Massachusetts, to regulate discharges into all waters of the Commonwealth of Massachusetts, including groundwaters. The DEQE regulates discharges through the issuance of discharge permits which impose limitations on the amount of pollutants which may be discharged in the effluent, together with monitoring and reporting requirements and other conditions to insure adequate treatment of all liquid wastes prior to discharge. The DEQE reviewed the application submitted on behalf of Jiminy Peak, Inc. for a permit to discharge sanitary wastes from the Jiminy Peak secondary wastewater treatment system located off Brodie Mountain Road, Hancock, Massachusetts, and subsequently developed the conditions contained in the Groundwater Discharge Permit No. Ø-188. More specifically, Jiminy Peak, Inc. (i.e. the permittee) has been authorized to discharge into the ground from the Jimmy Peak secondary wastewater treatment facilities for which the Permit No. Ø-188 was issued, a treated effluent

Jan 1, 1989

By T. I. Martinovic

A major investigative' program was conducted on the development of an acceptable substitute organic binder for bentonite for the pelletizing of the Iron Ore Company of Canada's Carol concentrate. The first phase of the program covered an evaluation of several organic binders in laboratory tire balling in order to identify the most promising potential organic binders. Based on the green ball quality obtained, Peridur C-10, Alchem 8C26 and peat moss were selected for full scale pot-grate testwork. The selected binders were tested with various pelletizing mixes (acid, dolomite, limestone and fully fluxed). The pot-grate test results showed that an acceptable pellet quality can be produced with the use of Peridur C-10.

Jan 1, 1989

By Scott A. Howard

MgO is routinely used as the basis for refractory materials, however, its susceptibility to hydration may result in dimensional instability and subsequent failure. The addition of boron has been shown to reduce th,e hydration susceptibility of MgO yet its dissolution into certain grades of steel may degrade their performance. In order to predict the efficacy of reducing hydration susceptibility by the incorporation of mono-, di-and tri-and quadravalent cations, the lattices of various cation-substituted systems were modeled. To more accurately simulate the substituted lattices, either cation or anion vacancies were incorporated to maintain electrical neutrality and all possible arrangements of defects in a 2x2x2 MgO supercell were investigated. Correlations were then made between the lattice energies of these systems and their susceptibility to hydration as reported in the literature. The results indicate the presence of higher charged cations tended to increase lattice stability while the cations with lower valency tended to have lower lattice energies. The relatively small body of experimental results available in the literature are consistent' with this study's results.

Jan 1, 1989

By Thomas M. Barczak

State-of-the-art longwall roof supports provide effective strata control, but failures of these support systems still occur. To identify failure mechanisms and the impact these failures have on the safety of the support system, the U.S. Bureau of Mines has been conducting research on shield mechanics in the Bureau's unique mine roof simulator, as well as field studies of in situ support loading and investigations of longwall failures, Three types of failures are discussed: (1) inadequate support capacity, (2) structural failure, and (3) instability. Hypothetical situations with proposed courses of action and case studies of actual longwall failures are described. This information is intended to assist the Mine Safety and Health Administration (MSEIA) and industry mining personnel in safety evaluations of longwall roof support systems.

Jan 1, 1989

By R. L. J. Phillips

"The environmental impact of the Rabbit Lake project is presented. Baseline data for fish, water, air and radon collected in 1973, 1975, 1980and 1986, are compared with post-development environmental monitoring data. Predicted environmental impacts for the developed Rabbit Lake and B-zone deposits are compared to the actual impacts. INTRODUCTIONThe environmental impact of the Rabbit Lake project has been documented through the years in several submissions to the government agencies. In 1972, the environmental baseline study for the Rabbit Lake area was completed prior to any mining activity at the Rabbit Lake pit (Fig. 1).Sampling concentrated on Hidden Bay and Pow Bay, which received the treated effluent and the waters drained from Rabbit Lake respectively.A second baseline study was done on the Collins Bay area in 1980(Fig. I) in preparation for the mining of the B-zone pit. The detail in this study was considerably greater than the detail in the previous study. Collins Bay and Harrison Peninsula were the areas sampled. The B-zone deposit is being mined at present.With the discovery of the A-zone, D-zone and Eagle Point deposits, it was decided in 1986 to begin proceedings to obtain approval from Saskatchewan's Department of the Environment, and from the Atomic Energy Control Board to develop these deposits.In preparation, a third baseline study of both the Rabbit Lake and Collins Bay areas was done in 1986 and 1987. The emphasis was to establish the baseline at the three new deposits, to quantify the actual impacts of the existing Rabbit Lake operations and to confirm the Collins Bay B-zone (1980) impact predictions. The new deposits will allow us to continue to produce uranium into the future. In January 1988, Saskatchewan approval was received.Since 1975 in the Rabbit Lake area and 1980 in the Collins Bay area, routine environmental monitoring has been done. This has resulted in one of the largest and most comprehensive environmental data bases in North America in mining. By the time the Eagle Point deposit is mined to completion, there will have been data collected for approximately 40 years.Further discussions follow which describe the impacts of the past (1972 to 1984), the present (1985 to 1987) and the future. In addition, the past and present performances and the future plans of the .waste management systems will be discussed."

Jan 1, 1989

By J. Trimble, B. M. Davis, D. McClure

During initial mining operations at the Colosseum gold mine, discrepancies between the average blasthole grades and mill-head grades were quite large. In December 1987, mill-head grades averaged 39% lower than corre¬sponding estimates from the blastholes. The correlation between average blasthole grade and mill-head grade had an r-value of 0.015. The magnitude of the discrepancy and the lack of correspondence between estimated and actual grades led to a series of investigations of the sampling system, the effect of blast movement of the ore, and the estimation methodology. The discrepancy between blasthole grades and mill-head grades had been reduced by about half on a percentage basis at the conclusion of these studies. Ongoing studies have produced changes that reduced this discrepancy to its present level of less than 10%. Geology The Colosseum mine is within the Clark Mountain mining district about 68 km (42 miles) southwest of Las Vegas, NV in San Bernardino County, CA. Gold mineralization at the deposit is hosted in two 152 m x 213 m (500 ft x 700 ft) interconnected, rhyolitic intrusive breccia pipes that intruded Pre¬cambrian crystalline basement rocks and overlying Paleozoic marine sedimentary rocks. Subsequent erosion (deroofing) of all of the Paleozoic section and a portion of the Precambrian section has exposed the pipes to the present level (probably a significant depth in the original breccia pipe system). Lithologies exhibited within the breccia pipe complexes include rhyolitic felsite, and breccias of felsite and wall/ country rock. Breccia types grade from felsite plus Precambrian granite-gneiss fragments in an aphanitic felsite matrix to crosscutting breccias of felsite, Precambrian granite-gneiss, and Paleozoic sedimentary rocks in a matrix of finely comminuted material of the same composition. All the lithologies in and around the breccia pipes exhibit moderate to intense quartz-sericite-pyrite alteration, with sericite and pyrite the dominant visual alteration minerals. Gold at the Colosseum mine is generally submicroscopic and associated with sulfide mineralization, chiefly pyrite. It occurs as free gold, with minor alloyed silver. It is primarily in contact with pyrite in fractures or along pyrite grain edges. Secondarily, it appears as isolated particles in quartz and other gangue minerals but spatially always close to pyrite, and rarely as particles encased in euhedral pyrite. The pyrite mineralization and minor base metal sulfides occur in three distinct styles: as disseminations, as open space or vein/fracture filling, and in breccia clasts replacing dolomite. The pyrite megascopically ranges from absent to 30% of rock volume within the breccia pipes. Although the gold at Colosseum is apparently spatially and geochemically associated with pyrite, there is only a general proportional relationship between pyrite content and gold content. Sometimes, a high volume percentage of pyrite has only geochemically anomalous gold. This makes visual pyrite only a general grade control tool and not a specific tool. This further makes the ore control process at Colosseum all the more difficult. Initial grade control procedure Initial grade control was based on blasthole samples collected in two stages by an "automatic" sample collection device (rocket sampler). A sample was collected for the top 3 m (10 ft) in a hole. The bag was then changed so that a sample was collected for the lower 3 m (10 ft). Each sample was prepared and fire assayed to determine the grade. Large discrepancies were sometimes noted in the assays of top and bottom samples. The samples were averaged together and a plot was made showing the blasthole locations and their associated grades. Discrimination between ore and waste was based on as-

Jan 1, 1989

By T. Yun

The process automation of coal production is one of the important component parts for achieving the modernization of coal industry. To realize the coal mining process automation serves the significant, function of increasing productivity, improving the quality control of raw coal, making efficient use of mineral resources, saving energy and is of great importance in enhancing the safe operation and improving the labour conditions as well.

Jan 1, 1989

By Benkendorff P. N

Cement production in Australia approximates 6.5 million tonnes per year. Cement clinker is sourced from 15 plants which operate 28 kilns. Cement grinding is conducted at 14 of the clinker plants plus 7 grinding plants. Average annual capacity per kiln or plant is lower than in many overseas countries, but kilns introduced since 1970's have been of larger size more in keeping with size trends overseas, although still smaller than the large units overseas. Substantial economies in capital and labour costs can be achieved in large production units, particularly with dry process kilns using precalcination techniques in which part of the fuel is introduced in the static preheater section ahead of the kiln while the balance is added to the kiln in a conventional manner. Precalcination techniques have been introduced to the Australian cement industry but as cement transport costs form a major part of supplying diverse market areas, the size of kilns is likely to remain less than maximum owing to balance with distribution costs. The cement industry uses significant amounts of thermal and electrical energy which can be minimised by proper selection of equipment and technology. Labour costs are also significant and can be contained by automation and computer control of the process.

Jan 1, 1989