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By M. J. Sapko

The US Bureau of Mines conducted, through joint funding with the Colorado Mining Association, large scale oil shale rubble fire tests to investigate flammability characteristics and different methods of extinguishment. Ignition of large rubble piles was easily accomplished. Foam blankets could he used to control surface flames. The results of these large scale tests confirmed that water was effective but not particularly efficient in extinguishing deep seated oil shale fires. It took up to 1.7 times as much water to extinguish afire as anticipated on the basis of a simple cooling model, assuming 100% utilization.

Jan 1, 1990

By V. L. Zajakowski, J. D. Gargulak

The current political climate has forced multinational cement manufacturers to consider technology that minimizes GO, emissions. Along with this environmental issue, individual manufacturing facilities are under constant pressure to increase productivity and lower costs. The use of processing or functional additions can help address these difficult demands by maximizing the extender content in blended cements. Recently, cement standards have been modified such that additions can be employed to improve quality. By using these "cement performance enhancers," the cement manufacturer can maximize extender content of cement thus optimizing plant economics, while meeting local quality standards and minimizing greenhouse gas emissions.

Jan 1, 2003

Simulation models were developed at the Julius kruttschnitt Mineral Research Centre to provide accurate estimates of power consumption for a wide range of equipment. With the models, a range of circuits and operating conditions can be compared by simulation for a particular ore type. Accurate models of classification allow for the interaction between classifier efficiency and target product size (e.g., P80 or percent passing 150 /an) to be considered. This paper considers a range of circuit types and overall energy efficiency in the context of case studies where different circuit types were treating similar ore types.

Jan 1, 1999

By Gao Zhizhong, Zheng Shibo, Gu Zhengxing

Extensive research on the beneficiation of Florida dolomitic phosphate pebble has been carried out by Lianyungang Design and Research Institute of China (CLDRI) in recent years. Test results indicate that the fine-particle flotation process could be used to effectively recover the phosphate values from Florida high-dolomite phosphate resources. With the CLDRI fine-particle flotation technology, a phosphate concentrate with 31% P2O5 and less than 1% MgO could be obtained from a flotation feed containing 25.8% P2O2 and 2.2% MgO at an overall P2O5 recovery of up to 85%.

Jan 1, 1999

By Graeme Lyall, Oy Leuangthong, Clayton V. Deutsch

There are many variables to consider in the evaluation of nickel laterite deposits including the concentrations of nickel, iron, silica, and magnesia. These variables show complex relationships with each other such as mineralogical constraints, non-linear correlation, and heteroscedasticity. The complex multivariate relationship between the variables cannot be reproduced by conventional Gaussian or indicator geostatistical techniques. We introduce the stepwise conditional transformation method as a pre- and post-processing multivariate transform for the stochastic simulation of a nickel laterite deposit. Transformed data are multiGaussian and independent at h = 0; thus, cosimulation can be avoided after verification that variables are independent at all lag distances. Back transformation restores the features of the input multivariate distribution to the simulated realizations. The complex multivariate correlations are reproduced and sensitivity issues are addressed.

Jan 1, 2002

Maximising margins in competitive markets demands superior productivity. Unfortunately, management systems developed early this century for other industries often drive counterproductive behaviours choking mining productivity. Many executives and managers waste valuable time and effort relying on simply training and communicating to improve managerial practices and attitudes. In covering practical human behaviour, the paper explains why this fails - and explains how to use systems to successfully drive improved managerial practices and attitudes. It highlights use of modern performance Measurement, Analysis and Reporting systems to drive behaviours and improve margins - without capital investment - and make executive and managerial work easier and more effective.

Jan 1, 1999

By Dale J. Sadowski, Richard J. Switalski, Kyle R. Ott

This paper discusses design and construction aspects of shaft construction through rock saturated with petroleum hydrocarbons (crude oil). During the subsurface exploration phase for design of the Hilltop Interceptor project in Cleveland, Ohio natural crude oil was encountered at depths between 6.1 and 61 m below ground surface. The oil-saturated Euclid sandstone contained up to 12,000 mg/kg total petroleum hydrocarbons (TPH), various volatile organics, and had flash points as low as 18.9°C. Interceptor hydraulic design required that construction of access and/or drop shafts penetrate the layer of petroleum hydrocarbon saturated rock. This led to the design of a special lining and some special handling procedures for the excavated material.

Jan 1, 1995

By G. Kazonich, S. L. McGill, J. W. Walkiewicz

Naturally occurring minerals and reagent-grade compounds were tested to determine their receptivity to microwave heating. The maximum temperature achieved for the samples and the time required to reach temperature are reported. A description of the microwave oven and a thermocouple technique that accurately measures and continuously records the temperature of samples during irradiation are reported. Extractive applications using the generated microwave data were investigated. Stress fracturing at mineral grain boundaries in a gangue matrix was shown. This should significantly affect grinding energy requirements and liberation properties. A method to produce a magnetic phase on pyrite surfaces, a method of using microwave heating to retort cinnabar concentrate, and a roast-leaching microwave treatment of chalcopyrite ore are described.

Jan 1, 1987

By Ben H. Daud

A computer model has been developed at Consolidation Coal Co.'s Central Engineering Dept. for preliminary economic evaluation of deep coal mine reserves. Since it was first formulated more than two years ago, the model has been used for the following purposes: (1) ranking studies of coal exploration projects, (2) marketing surveys, (3) preliminary sale and acquisition analysis of coal reserves, and (4) parametric analysis in conjunction with detailed feasibility studies.

Jan 1, 1979

By Kal V. S. Sastry

Mineral processing simulation has come a long way since its beginning about thirty years ago. With our increased understanding of mineral process systems and the advent of new software and hardware technologies, we can visualize an ideal mineral processing simulator. This paper attempts to identify a number of desirable features of an ideal mineral process simulator and to describe the exciting trends in making such an ideal simulator a reality.

Jan 1, 1992

By G. D. Ritson

Gold surveys were sent to 21 gold operations around the world. Eleven different surveys were sent, each targeting a dif­ferent unit operation used commonly in gold processing. On a monthly basis the individual reports were returned to the opera­tions. Empirical data collected during the surveys has con­tributed to more effective engineering design. Graphical rela­tionships established have been used by the operations to "benchmark" performance against the industry and identify areas of possible improvement. This paper presents some of the findings related to the fol­lowing four surveys that investigated parameters specifically relating to carbon processing. Rescan Gold Survey GO 1 - Carbon Management practices Rescan Gold Survey 003 - Carbon Stripping Rescan Gold Survey 006 - Carbon Loading Isotherms Rescan Gold Survey 007 - Screening A final report documenting all the surveys will be compiled

Jan 1, 1998

The National Mining Hall of Fame and Museum will hold its Ninth Annual Induction Banquet Sept. 8, 1996, at the Las Vegas Hilton Hotel. Six mining greats, two of them living, will be enshrined at the event. They will join 126 other mining legends previously honored by the hall of fame. The keynote speaker will be William Perry Pendley, president and chief legal officer of Mountain States Legal Foundation in Denver, CO. Jeffrey Zelms, president and chief executive officer of The Doe Run Co., will be master of ceremonies. Richard Swayne, regional director USA for Boart Longyear Co. of Salt Lake City, UT, will introduce the speakers. Thomas Falkie, president of Berwind Natural Resources Corp. and chairman of the Mining Hall of Fame’s board of governors, will enshrine the inductees.

Jan 1, 1996

By Terry M. Hertel

Zortman Mining has spent approximately three years evaluating the metallurgy of the sulfide ores from the mining area of the possible expansion project. As the test program proceeded, an interesting series of events took place which changed the scope of the work. During the agglomeration work, one of the control columns was inadvertently set up without the addition of lime to the material prior to loading and subsequent leaching. The gold recovery from this column was comparable to those columns that had a lime addition of 10 pounds per ton of ore. In fact, the gold recovery curve had a much steeper slope than those of the other columns. Furthermore, the pH of the pregnant liquor from the "no lime" column recovered to typical levels as fast as the solutions from the "lime" columns. These observations led to the concept that rinsing the ore with water prior to cyanide leaching could be advantageous to the heap-leach process.

Jan 1, 1992

By K. J. Stanaway

Environmental pressures on waste disposal are forcing pigment producers to use feedstocks with higher Ti02 content and lower levels of trace elements. Despite this, 50% of the world's Ti02 comes from ilmenite concentrates with only 37% to 54% Ti02. An industry growth rate of 25% in the next 10 years, combined with trends to diminishing resources and lower mining grades for rutile (95% P02) and leucoxenized ilmenite (55% to 90% P02), means that unless new discoveries are made soon, the industry will become even more reliant on ilmenite.

Jan 1, 1995

By J. Steven Whisler

Corporate managers are facing increasingly demanding challenges as they seek to ensure compliance with environmental laws. Management also must deal with new liabilities created by environmental laws. These laws provide both private groups and governmental agencies with access to the courts to seek penalties, compliance orders, cleanups, or to forestall developments that could affect ecosystems. Environmental laws and liabilities are also affecting commercial transactions, including the availability of financing. Corporate managers must develop new and innovative methods to address these challenges in order to assure both sustainable industrial growth and stewardship of the environment.

Jan 1, 1991

By Sheldon Shepherd

Fifty years ago, belt scales were mechanical devices based on a complex weight balancing design. Today's systems use load cells to assess material weight, belt speed sensors and microprocessor-based integrators to continuously compute the rate of material transferred along a conveyor. Belt scales have become important assets to a plant. They help maximize the use of raw materials, control inventories and aid in the manufacture of a consistent product. Choosing and installing a belt scale system may seem complicated but it can be simplified by following a few guidelines.

Jan 1, 1999

By David G. Chedgy, Edward A. Zawadzki, Robert D. Stoessner

Extensive research and testing in commercial facilities has clearly demonstrated that heavy medium cyclones are the most effective process for cleaning a 0.6 x 0.15mm (28 x 100 Mesh) coal at low separating gravities, less than 1.35. This paper describes testing performed to deter- mine system characteristics at these lower gravities and the type of circuitry required to maximize performance. The results of these studies include both pilot and commercial scale tests of cleaning 0.6 x 015mm (28 x100M) coal.

Jan 1, 1988

By Kurt O'Bryan, Gary Beerkircher

WaterFlush Technology offers maximum comminution performance benefits over to­day's more common comminution methods. These benefits will be presented with case studies of existing installations, and the projected performance gains for circuits scheduled to begin operation in 1992.

Jan 1, 1992

By Donald D. Haas

This presentation will discuss a mine owner's evaluation to utilize a contract miner in the development and production of gold properties. I will address both the quantitative and subjective aspects of the evaluation process. The quantitative aspects include cost evaluation, capital preservation, acquisition and disposal of new and used equipment, administrative costs, recruiting and training, and organizing a staff and craft labor force. The subjective areas of this discussion include corporate philosophy, administrative concerns, contractor competence, loss of owner control, operating flexibility, financing assistance, recruiting and training program utilization and risk reduction. The evaluation of alternatives provides a system for comparing, on a cost basis, an owner/operator system vs. a system using a contract miner. The supplement provides a concept on how a contract miner may be the cost effective system to be utilized.

Jan 1, 1989

By Lawrence M. Lenahan

Cleveland's Southwest Interceptor Contracts No. 3 and No. 4 are continuations of Contract No. 1 addressed at the 1987 RETC with geology, equipment, and methods that differ greatly. The two contracts consist of 791 m (4.22 miles) of 3.5 m (11.5 ft) tunnel lined to 2.9 m (9.5 ft), nine access shafts, six drop shafts, and six collection structures. The excavation drive was completed by the use of a 1970 vintage Robbins TBM hybrid for this particular job through the use of both new and old technology. All other excavations were successfully accomplished through drill and blast method in tight residential areas. Concrete lining and connections were completed nine months after holing through.

Jan 1, 1989