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By Kenneth P. Neumann

The development of the Cyprus Thompson Creek Molybdenum Deposit near Challis, Idaho, began in 1967 when the first mining claims were staked on the intrusive rock outcrop. Exploration drilling continued for the next 14 years. During 1978, a decision was made to develop the deposit. In December, 1980, approval of the Environmental Impact Statement was received and construction of facilities and waste rock removal began. By the middle of 1983, 126 M metric tons of rock had been removed and all facilities were completed. The high work ethic of Cyprus Thompson Creek employees combined with innovation has made the mine one of the most efficient in the United States today.

Jan 1, 1983

By D. Houghton

"I am very pleased to be a member on this panel today because abrasion and wear in mills has been part of my life over the past forty years. My presentation will deal with the role Ni-Hard has played in combating wear and abrasion in mills. Before Ni-Hard came along, unalloyed white iron was used in ball mills and one of the most popular types of white iron liners was the pocket liner. Slide #1 illustrates the design of the pocket liner used at Dome Mines in their 5' x 22' pebble mills. The pockets filled with grinding media and it was on this that the wear took place. The concept is not unlike the new magnetic liner which utilizes the ore and grinding media to form the wearing surface. In this slide please note the tapered pocket type of cored bolt holes. If cored bolt holes do not fill with grinding media there could be excessive grooving or wear at that area. Therefore all cored bolt holes should be tapered in this manner.Before Inco patented the name Ni-Hard several foundries were making the alloy iron under different brand names such as Diamond Alloy, Mitchelloy and Specialloy. In the early days some of the Ni-Hard was poor quality. Inco provided foundries with technical knowhow and provided assistance to licence them to sell under the name of Ni-Hard. This was in the late 1920's. The material we are discussing is Ni-Hard type I with the following analysis (slide #2). It is a martensitic white iron with BHN of 550 - 600 and is a relatively easy alloy to produce in either a cupola or electric furnace. The annual average production of Ni-Hard in North America is 90,000 tons with mill liners making up 25,000 tons and grinding media 30,000 tons, according to Warren Spear of Inco."

Jan 1, 1983

The term "joint venture" lacks any precise legal definition but is typically used to denote a form of legal relationship which is neither a partnership nor a corporation. Nbst joint ventures are contractual relationships which provide for the sharing of mining leases and production facilities and for the sharing of costs, but which enable each joint venturer to carry on his own separate business. The rationale for such relationships is that each participant: retains independent taxation status may independently grant direct security over his interest in the project assets for financing purposes Bankers prefer to lend to incorporated joint ventures (i.e. corporations in which all of the joint venturers are shareholders) but will lend to individual joint venturers provided the joint venture agreement does not imperil their security; i.e. provided there is a "bankable" joint venture. The carpeting objectives of joint venturers and their bankers may be reconciled and unnecessary conflict avoided by the timely inclusion of appropriate provisions in the joint venture agreement before financing negotiations commence.

Jan 1, 1983

By K. Hanumantha Rao, T. C. Rao, M. Vanangamudi

The effects of important variables such as pulp density, feed size, furnace oil dosage, degree of agitation, and time of agglomeration on the yield and ash content of the agglomerates obtained from the oil agglomeration of coal fines have been studied in a laboratory batch agglomeration cell. Optimum conditions for maximum yield and throughput have been discussed. The furnace oil dosage and pulp density were found to have more influence on the yield and grade of the agglomerates than the degree of agitation and feed size in the ranges studied.

Jan 1, 1983

By James F. Albus, Vincent C. Grimshaw

High pressure fluid energy grinding, or jet milling, is a versatile method of continuously fracturing solids into fine particles to gain substantial increases in exposed surface area Applications in industrial minerals grinding include calcium carbonate, talc, barytes, mica, diatomaceous earth, bauxite, rutile, coal, kaolin, sepiolite, diamonds, etc The basic principles can be extended to provide continuous drying and delivery of discrete par¬ticles from a wet process slurry The main design and operational features of jet mills and dryers are described, relating energy consumption for both air and steam milling and hot air drying techniques Mean particle sizes in the order of 1 micron are achievable from pre-milled feeds, or maintained from similar slurries in the drying mode Aspects of feed preparation and multi-stage processing are discussed

Jan 1, 1983

By Douglas R. Piteau, Dennis C. Martin

Instability of rock slopes may occur by failure along pre- existing structural discontinuities, by failure through intact material or by failure along a surface formed partly along discontinuities and partly through intact material. Although certain fundamental failure modes are recognized, the mechanisms of slope failure are varied and complex. Such mechanisms are governed by the engineering geology conditions of the rock mass, which are almost always unique to a particular site. An understanding of failure mechanisms requires a knowledge of the physical, mechanical and strength properties of the intact material and discontinuities which make up the rock mass, as well as the structural geology and hydrogeology. These engineering geology parameters also must be evaluated with respect to the slope geometry to determine failures which are kinematically possible. Only after obtaining a reasonable appreciation of the possible failure modes can a rational mechanical stability analysis be carried out. Both two-dimensional and three-dimensional failure mechanisms should be considered in assessing the design of rock slopes. Simple analyses methods are used initially to identify those possible failures which could control slope stability. More complex and detailed analyses usually are required for a few critical failure modes which could control stability, or where a more complex type of failure mechanism is envisaged. Complex failure mechanisms are usually identified when assessing previous slope failures. More detailed information concerning slope geometry and engineering geology parameters must be acquired where analyses must be more rigorous.

Jan 1, 1983

By L. A. Melis, K. S. Fraser

"This paper describes the development of a milling circuit for the complex Midwest orebody, containing a high-arsenic uranium ore typical of that found in northern Saskatchewan. The results of preliminary bench-scale test work are summarized. Data from a pilot-plant program carried out at the Ontario Research Foundation are provided for the selected mill flowsheet. Also described are waste circuits which have been established to produce effluents of acceptable quality. Pilot-plant testing of sub-aerial tailings deposition is also described. The applicability of manufacturers' equipment for the various circuits in the flowsheet is discussed.IntroductionThe Midwest uranium deposit is in northern Saskatchewan, 700 km north of Saskatoon, near the eastern edge of the Athabasca BasinDevelopment work on the project is directed by Canada Wide Mines Ltd., a subsidiary of Esso Resources Canada Limited. Participants in the project are Esso Resources Canada Limited, Numac Oil and Gas Ltd., Bow Valley Industries Ltd ., Mink Mining Corporation and Midwest Mining Corporation.The deposit consists of a series of flat lenses of massive ore overlain by a halo of lower-grade sandstone ore. The massive ore is formed of pitchblende and nickel arsenides, along with clay, and averages about 10% U and 9% Ni, The principal minerals are pitchblende (UO2-UO3), coffinite (U(SiO4)1-x(OH)4x), gersdorffite (NiAsS), niccolite (NiAs) and rammelsbergite (NiAs2). The sandstone ore, a friable clay-rich sandstone with sooty pitchblende, averages about 0.4% U and 0.6% Ni. Typical expected mill feed analyses are given in Table I.A bench-scale development program ore was carried out during the period from August 1978 to May 1981 in the laboratories of Lakefield Research of Canada Ltd. (Lakefield), (Lakefield, Ontario), the Colorado School of Mines Research Institute (CSMRI), (Golden, Colorado) and, to a lesser extent, the Ontario Research Foundation (ORF), (Mississauga, Ontario) and the Saskatchewan Research Council (SRC), (Saskatoon, Saskatchewan). Direction of the development studies was shared by Canada Wide Mines Ltd. and its metallurgical consultants, A.H. Ross and Associates. Input was received from Envirotech, Enviroclear, Interox America, and Knight and Piesold Ltd."

Jan 1, 1983

By N. Malakouti, R. H. Whipp, O. A. Kuby, R. M. Smailer

A detailed description of the development of the FIOR process (Brown, Campbell, and Saxon, 1966) and, subsequently, other technical papers related to the operation and start up of the FIOR plant (Violetta, 1975; Whipp, 1980) are available in the technical literature. The Fluidized Iron Ore Reduction (FIOR) process plant constructed in the Matanzas region of Venezuela represents the first commercial application of this technology. The FIOR process was developed by Exxon Co. during the 1950s and 1960s. The facility in Venezuela was designed and constructed by Davy McKee, with plant start-up in 1976. While there is a minority government ownership in the company, FIOR de Venezuela operates as a private sector company with the majority of ownership being private capital. The FIOR process is well suited to utilize the naturally occurring iron ore fines of the Cerro Bolivar and San Isidro iron ore deposits located less than 100 km (62 miles) south of the plant site. Availability of natural gas within 150 km (93 miles) to the north, and a location bordering on the confluence of the Caroni and the Orinoco Rivers makes for an ideal geographic site. Feed stock to the FIOR plant consists of naturally occurring iron ore fines from these ore bodies, which are screened to -6mm (-0.2 in.) prior to drying in the ore preparation plant. A simplified flow plan is shown in [Fig. 1]. The dried ore is then transferred to the top of a structure containing four fluid-bed reactors located above one another so the mineral may flow from one reactor to the next by gravity. A reducing gas containing 90% hydrogen is made by steam reforming of natural gas, a CO shift

Jan 1, 1983

By Ruth A. Holmes

A Bureau of Mines method for recovering nickel, cobalt, and copper from low-grade domestic laterites is described, which includes the unit operations of solvent extraction and electrowinning. Previous Bureau work indicated that addition of Na2S04 (sodium sulfate) to the nickel electrolyte improved current efficiency in nickel electrowinning. The present study determines the compatibility of Na2S04 with nickel strip-ping in the solvent extraction operation of the Bureau method. The effect of adding 100 g/l Na2S04 on nickel stripping, phase disengagement, and pH was determined in comparative laboratory-scale tests. In continuous-circuit testing, Na2S04 reduced stripping efficiency to the extent that five, instead of four, strip stages were required for complete stripping of nickel from the loaded solvent. In tests made in a phase-disengagement cell that had a variable settler area, the addition of Na2S04 did not significantly affect phase separation characteristics. The pH of the nickel electrolyte in the temperature range of 20° to 65° C was also unaffected by the addition of Na2S04. An economic evaluation showed that the energy saved by adding Na2S04 to the electrolyte would more than offset the cost of adding another stripping stage.

Jan 1, 1983

By David E. Thompson, Edward S. Plotkin

The Massachusetts Bay Transportation Authority (MBTA) Red Line Extension Northwest is nearing the final stages of construction. The 3. 1 mile extension of the Red Line from the existing Harvard Square Station in Cambridge, Massachusetts to Alewife Brook Parkway in Cambridge, includes a large, near surface, hard rock, rapid transit chamber at Porter Square in Cambridge (Figure 1).

Jan 1, 1983

By Leslie S. Rubin, John C. Roberge, Mackenzie Burnett

A self regulating helical inducer has been developed and tested for dry injection of coarse or fine solids into a hydraulic pipeline. This centrifugal pumping device has also been modified and tested for use as a boost pump in medium and long distance pipeline haulage systems. The helical inducer has been operated as an integral component of a slurry injection vehicle. This compact, low profile vehicle also includes crushing and screening components, solids feeding components, a track drive system for mobility and is run by a single operator. The helical injector and boost pump operate without speed and flow controls allowing for the practical hydraulic transport of excavated materials.

Jan 1, 1983

By Gene O. Cowie

"Zinc, which once enjoyed an unchallenged position in the field of decorative applications, has lost a substantial share of its markets to other materials, particularly plastics. This turn of events has led the zinc industry to explore new market areas, particularly those applications where the engineering properties of zinc can be utilized. This paper gives an overview of the zinc industry's efforts to develop the data base and product development technology which have enabled zinc alloys to emerge as engineering materials. It also indicates those areas in which the research facilities of the zinc industry must be employed to ensure that zinc alloys keep pace with developments in competitive materials and processes.The Materials RevolutionThe development and utilization of new materials and manufacturing processes progressed for centuries by evolution. Recently it erupted into a revolution, which may become as significant as the industrial revolution. The materials revolution has impacted upon many industries, but none has been affected more traumatically than the North American automotive industry. The plight of that industry is of great importance to us because their problems have, to a great degree, become problems to the zinc industry.Much of the impetus behind the automotive trauma came from the battery of motor vehicle regulations promulgated by the United States government in the 1970s. These regulations required that the efficiency of passenger cars, in terms of miles per gallon, be approximately doubled in ten years. In view of the fact that major changes in the automotive world require three years of lead time to implement, the industry was left with only seven years to perform the task. The automotive industry was simultaneously required to make progress in other areas, such as reduced emissions, reduced cost of repairs and increased levels of occupant safety. These added demands not only diverted some of the available resources away from efficiency goals, they often ran in direct conflict. For example, when you are required to provide a front bumper which will absorb the energy of a 5-mile -per-hour barrier collision, you must add both hardware and structure to the vehicle. This adds weight, and increased weight reduces miles per gallon."

Jan 1, 1983

By D. Y. Geng

Longwall mining is a relatively new mining method in the United States. Early trials in the eastern and central coal fields were not successful, mainly because, among others, the face supports did not have sufficient capacity. It was not until in the late 1960's, when the high- capacity self-advancing powered supports became available, that longwall mining was successfully reintroduced. Since then the number of mines employing the longwall method has been steadily increasing. It has reached approximately 7.5% in 1981. Currently longwall mining is used mainly in the Appalachian coal field. The seam depth ranges from 150 to 2500 ft. but mostly between 300 and 1400 ft. The seam thickness ranges from 32 to 144 inches with the majority between 40 and 100 inches. Nearly all longwall mining are in flat or nearly flat seams extracting in single slice, although one inclined and one thick seam longwall mining have been either operated or initiated in Colorado.

Jan 1, 1983

By Thomas W. Turk

The water treatment industry has historically been involved with reducing or inhibiting the inherant scale forming or fouling tendencies of natural waters associated with large industrial cooling water systems. Fouling is an extremely complex phenomenon. From a fundamental point of view, it may be characterized as a combined momentum, heat, and mass transfer problem. Chemical reaction kinetics is involved, as well as the solubility characteristics of salts in water and corrosion technology. It is a routine practice to over size pumps, piping and heat exchangers to compensate for fouling.

Jan 1, 1983

By C. Hosten

This paper presents the results from an extensive research program on the vacuum filtration of iron ore slurries. Experiments were conducted with the addition of several types of flocculants and surfactants. The filtration response of the slurries was studied in terms of the cake formation rate and the residual cake moisture. An analysis of the results is presented in ascertaining the role of flocculants and surfactants during filtration

Jan 1, 1983

By Eileen Ashworth

Computer-assisted instruct ion is now being used in areas as diversified as training handicapped children to preflight simulation for airline pilots. This paper reports on two courses that have been developed at SDSM&T on the PLATO system for miner safety training. Advantages of computer-assisted instruct ion for this type of training is discussed. (Figures show examples of actual use.) A discussion will be given on other applications such as maintenance troubleshooting, training of engineers and managers at remote sites and training of local people for working in the mine.

Jan 1, 1983

By Betty L. Gibbs

A company must have an organized approach to effectively sort through the profusion of available software and hardware and find the programs and equipment which fit defined needs. The selection process must build a complete compatible system which includes hardware and software. The methodology presented in this paper helps identify some of the more important considerations. The steps needed for an organized approach to software/hardware selection are: •All involved staff should contribute to an assessment of current computer capabilities and projection of future needs. •Alternatives are analyzed to determine what software and hardware is available and how selections may possibly be merged into the existing computer system. The evaluation process focuses on details of program capability and hardware compatibility. Analysis must be done to determine how closely individual programs fit the established requirements. The final decision is often a balance of needs between program capabilities and hardware availability. Any programs selected must be able to run on existing and newly purchased hardware. Any additional hardware selected must be capable of meshing with the available computer system.

Jan 1, 1983

By Steven T. Mitchell

INTRODUCTION Mill production from the Homestake Mine in 1979 amounted to 1.29 Mt (1.43 million st) of ore containing 5.9 g/t of gold (0.172 oz per st) compared with 1978 production of 1.44 Mt (1.59 million st) containing 6.2 g/t of gold (0.180 oz per st). The average cost per ounce of gold produced in 1979 rose to approximately $250 contrasted with $176 in 1978. This increase in unit cost is the result of inflation, a diminishing ore grade, and productivity losses related to a shortage of experienced miners as well as compliance with federal regulatory requirements. Together, these factors prompted the investigation of several large-scale, highly mechanized underground mining methods. This analysis indicated Vertical Crater Retreat mining to be one of the safest underground methods known today, yet competitive with all other forms of stoping in terms of cost and productivity. Therefore, the feasibility of applying the VCR stoping method at the Homestake Mine was explored. Vertical Crater Retreat stoping is a recent innovation in large- scale underground mining based on C. W. Livingston's crater blasting theories. Figure 1 illustrates the method which consists of drilling 165.1-mm-diameter (6.5-in.) holes from a topsill down-dip to an under- cut on the level below. The bottom of each hole is then loaded from above with a predetermined charge weight and horizontal slices up to 4.27 m (14 ft) in thickness are blasted into the undercut. Broken ore is extracted from drawpoints located on or below the undercut level.

Jan 1, 1983

By Jay N. Fairbanks, Richard G. Robinson

This paper discusses a computer program and related formulas for fire fighting responses by coal mine personnel. The computer will interpret the mine air analysis, print reports, and provide relevant graphs allowing quick and accurate responses to coal mine fires.

Jan 1, 1983

By Mark Springett

The problems inherent in sampling low- grade deposits have long been recognized. As economic grades become lower with increasing metals prices and improvements in recovery technology then the previously difficult sampling problem has consequently become even more demanding. The breakdown of the sample process and error is illustrated by describing in the remainder of the paper some sampling practices that have been utilized on mining and exploration properties and by describing some problems that have been encountered, providing a series of cautionary tales to those involved in any aspect of mine or exploration sampling.

Jan 1, 1983