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By W. E. Crandall

The Star-Morning mine is a. 1000-ton-per-day lead-zinc producer located in the easterly part of the Coeur d'Alene Mining District of North Idaho. The property includes both the Star and Morning mines which are located on the westerly and easterly portions of the same complex of veins. The mine is 70% owned by the Bunker Hill Company (Gulf Resources, Inc.) of Kellogg, Idaho, 30% owned by Hecla Mining Company, and operated by Hecla Mining Company with head-quarters in Wallace, Idaho. One of the characteristics of mines in the Coeur d'Alene District is that many of the ore bodies extend to very great depths. The Star is no exception, but rather a leading example. The complex of near vertical veins and ore shoots extend some 7000 feet below the surface at present, with a maximum strike length of about 4000 feet. Ore has been mined on 20 separate veins and ore structures. More than 50 miles of headings have been driven and nearly 23 million tons of ore mined since the Morning mine started in.189S. The problems of mining at such depths are formidable temperature on the bottom level is 1100 F and high humidity problem. Pressure from the sheer weight of rock is as high foot. This paper will deal with providing a new access to the deeper levels of the mine and the installation of a hoist and related items to service these levels. By the time development had reached the 7100 level (Figure 1), it became apparent that a different 'hoisting system was going to be necessary if we were going to continue to mine at a profit. The main shaft extended to the 4000 level at which point a ?:3100"'foot winze shaft provided access to the 7100 level. The two hoists were limited to handling 3-ton payloads at 1200 to 1500 feet per minute. Some ores are still produced from above the 4000 level but as these ore reserves become depleted the hoisting of the desired tonnage (1000+/day-) from the lower levels of the mine would exceed the capacity of the existing hoisting system. A decision was made to sink a new vertical shaft at a point well in the south wall of the ore bodies where strong rocks and a minimum of faulting was expected and to purchase and install a new hoist capable of hoisting over 7000 feet. This new' shaft, designated as the No. 4 Shaft, was planned to reach 2000 feet below the 7100 level which was the deepest level at that time. The hoist would be in-stalled on the ,main 2000 Adit level which is used as an access and haulage level to the concentrator and surface plant in Burke.

Jan 1, 1971

By Wilson Blake

The occurrence of rock bursts in some deep mines throughout the world constitutes a severe operational hazard. In addition to endangering the safety of the miners, the rock-burst problem is a major factor in mining economically in deep mines because of the loss of production and expense owing to cleanup and repairs following a burst. Developing means of controlling or eliminating rock bursts has been the subject of intensive research for over 50 years. While much has been learned about the effects of rock bursts, little is known about their basic causes; hence, control measures have been at best only partially effective--attested to by the number and severity of bursts that continue to occur throughout the world each year. In the Coeur d'Alene mining district of north Idaho, the rock-burst problem continues as the silver and lead veins persist at depth. These veins are presently being mined at greater than 7,000 feet below the surface and will be mined to some 10,000 feet in the future. The majority of rock bursts in this district occur in pillars. While pillar bursting has been essentially eliminated in some deep-mining districts by longwall techniques, modification or application of this technique to the thin, irregular, and near vertically dipping veins of the Coeur d'Alene district has not been found to be practical. The creation of pillars is a consequence of the horizontal cut and fill mining method used. Figure 1 shows a vertical longitudinal projection of the silver vein at the Galena mine, illustrating the mining method. Stoping progresses between raises and is carried upward between levels. A horizontal pillar is created as a stope approaches a mined-out level. Recent broad-band micro seismic monitoring of rock-burst-prone stopes by the Bureau of Mines has shown that potential burst zones could be delineated weeks in advance of a burst and that a definite sequence of events took place prior to the occurrence of a pillar burst (1). Hence, time was available for control measures to be effected when a stope pillar reached a critical burst geometry.

Jan 1, 1971

By D. S. Burgess

A commercially available Halon 1301 extinguisher has been evaluated as part of an explosion-suppression system for use in coal mines. Studies were made both of the dispersion pattern of the Halon 1301 at an initial pressure of 280 psig, and of the efficacy of this suppressant against 9.5 percent methane-air flames. These flames were quenched successfully only when the suppressant was applied before the fireball diameter exceeded 18 inches.

Jan 1, 1971

By Harold J. Polta

This Bureau of Mines publication considers the feasibility of augmenting the present transportation system by pipelining taconite concentrates from the Mesabi Range to the Chicago area. The cost of pipelining in the hypothetical system using water as the carrier is estimated to be between $3.66 and $3.97 per long ton. This appears competitive with the 1970 rail-vessel transportation rate of $4.08 even after allowing a few cents per ton for barging from the terminal to existing furnaces. Political obstacles requiring solution before such a pipeline could be built and the feasibility of using crude oil as the carrier fluid are also discussed. FORTRAN routines used to calculate unit transportation cost for specific estimated values of cost items and for a range of values are presented. The effect of deviations from estimated values of cost items on the total unit transportation cost are shown graphically.

Jan 1, 1971

By Martin G. Casto

Mixer-settler extractors, among the oldest forms of extraction equipment, have been used since the beginning of this century. Over the past years, a very large number of mixer-settler devices have been designed and operated. Both batch and continuous flow mixer-settlers have been used. The continuous flow mixer-settler extractor offers a great number of advantages over other extraction equipment. The main advantage of the continuous flow mixer-settler is that it is a compact device. A large number of stages can be assembled in a relatively small area, and more stages can be added fairly easily. Many improvements have been made in the design of mixer-settlers. These improvements occurred in almost every phase of mixer-settler' operation; interface control, mixer design, intrastage pumping, interstage flow of the two liquid phases, and stage construction. It is believed that Barstow1 used one of the first continuous mixer-settler extractors. This mixer-settler had concurrent flow within each stage and countercurrent flow overall. The flow for both phases took place by gravity. The Barstow device and other early mixer-settlers had no separate interface control for each stage, therefore, "tilting" of the stages was necessary. In 1934 Holley and Mott2 designed a mixer-settler in which the heavy phase was recirculated within each stage by the use of a valve controlled central line instead of by a pump. Gordon and Zeigler3 in 1939 were among the first to use an adjustable valve to control the interface levels in a mixer-settler, making tilting of the extractor unnecessary. In 1952 Coplan et al. 4 used a modification of the Holley-Mott idea to build a highly improved mixer-settler with flat common walls, and with the

Jan 1, 1971

By Lester J. Crow

A preliminary survey was performed to investigate the impregnation of relatively weak, porous volcanic tuff and a relatively strong, dense sandstone with five different monomers. Increases in compressive strengths by factors of 2 to 5, and elastic moduli by factors of 2 to 3.5, are reported for natural rocks (tuff., sandstone, dacite), which were impregnated with five monomers (methyl methacrylate; chlorostyrene; 40 percent TMPTMA-60 percent styrene; 40 percent TMPTMA-60 percent chlorostyrene; 60 percent polyester-40 percent styrene); polymerization took place after monomers were forced into the rock. Impregnation was performed (1) by pressurizing rock specimens from one end, or (2) by a vacuum-soak operation. Polymerization was accomplished by either radiation or chemical initiation techniques. Strength improvement is dependent on (1) the type of monomer used, (2) the amount of polymer incorporated into the rock, and (3) the degree of water saturation of the rock. Water saturation strongly reduced the effectiveness of the method for the polymer systems tested. The more viscous monomers (for example, 60 percent polyester-40 percent styrene) were more effective in displacing the water from the rock, and compressive strengths of wet rock were doubled with these systems. Water saturations ranging from 25 to 100 percent of maximum saturation gave essentially identical results. Further tests on other types of mine rock; including shale and coal, are planned. Water-compatible polymer systems should be developed, or present systems should be suitably modified. For application to tunnel stabilization, design studies evaluating the improvement in rock strength and its influence on the support system are also recommended.

Jan 1, 1971

By g. Caproni

The main constituent of the feed to the "Sulphide Section" (31 t/h), in the F. Sartori Plant (6000 tid) of the Miniere di Mon)eponi(Sardinia), is the ore of the Campo Pisano -Funtanaperda Mine (1 ? Difficulties have always been experienced in the treatment of this ore, owing to the extramely fine Pyrite-Sphalerite intergrowth and to the high Pyrite and soluble salts contents. The first mentioned difficulty was overcome with a rather complex flowsheet (see fig.1A and lB)(2); the others with a reagent combination that required a pH of 11 in a pulp loaded with soluble salts. This meant high consumption of alkalizer, and also of the other reagents; furthermore the alkalizer had to be mainly NaOH with only minor amounts of lime, because the latter tended to depress not only the pyrite but also the middlings, which were supposed to float. With dialchylditiophosphate alone as a collector, a lower pH could have been used, but a certain amount of amylxanthate was indispensable to promote flotation of the middlings. On the other hand, a bulk-flotation of sphalerite and pyrite at low pH could not be very advantageous on account of the high pyrite content in the feed(3).

Jan 1, 1971

By Peter B. Knuckey

1, Introduction Location Kalengwa mine is located in the North Western Province of Zambia, 402 kilometre by unpaved road to the west of Kitwe, which is roughly in the centre of the Zambian Copperbelt, well known as one of the world's centres of copper mining. Its position is illustrated on the map of Africa in Figure 1 and on the map of Zambia in Figure 2. It is a mine of Roan Consolidated Mines Limited whose other properties, Mufulira, Luanshya, Chambishi and Chibuluma Mines, are all located on the Copperbelt. It is managed by the Chibuluma Division of the company. The rate of production from Kalengwa will vary from 12 000 to 17 000 tonnes of saleable copper a year over the next six years. Kalengwa did not exist as a place until the first prospecting parties and later the mine became established and the early working population was recruited entirely from small villages in the surrounding area as much as thirty miles away. The mining area consists of fourteen mining locations amounting to 3.35 square kilometres and the land may be used for any purpose connected with mining, including housing, wood cutting and other utilities. The whole area is, except for minor undulations, a fairly flat plateau with main rivers running from north to south and flood basins known as "dambos" located in a general east west direction. Vegetation is, with the exception of the grassy dambos, temperate forest with relatively light undergrowth. Game of great variety is prolific, as is the associated tsetse fly.

Jan 1, 1971

By Paul Javor

Optimization of a process is achieved by selecting, 'from all the known options, the most beneficial method of obtaining a product. It is rare that the optimum process is arrived at by conventional methods, because of the great amount of time required for developing and comparing all the options. On the other hand, it is now possible, by means of an optimization program based on special mathematical formulas involving an algorithm and implemented by a computer, to plot the optimum process realizing considerable savings and in a reasonably short time. The flow sheet arrived at in accordance with the optimization program described in this paper investigates and develops all the possible options and, with the aid of the computer, makes it possible to select the most economical ore beneficiation process. The options in an ore beneficiation process are all the possible trajectories that can be traced through the particle sizes to which the ore is reducible in the extraction of its valuable minerals. Although an ore can have a wide range of composition and several valuable minerals that can be extracted, this paper is concerned with the special case in which only one mineral is extracted from the ore and in which the maximum allowable percentage of impurities in the end product is defined.

Jan 1, 1971

By J. V. Thirgood

"Reclamation legislation was introduced in British Columbia in 1969 amidst public concern and controversy. This paper reviews this legislation as it relates to coal mining, and how it is being implemented.Although the principles of land reclamation are reason-ably well understood, reclamation of industrial wasteland has never previously been attempted under such rugged conditions as occur in the Canadian Rockies and a new methodology is being developed.The resolution of the technical and organizational problems involved are discussed and the techniques and experiences described."

Jan 1, 1971

By John E. Appleby

Grupo Acera, HYLSA originated in 1942 when Hojalata y Lamina began operations to supply steel strip for the Cuauhtémoc Brewery, the parent company. Production began in April, 1943 with growth accelerated because of World War II. By 1948 the company was producing its own steel from electric furnaces charged with scrap iron. Further expansion was hampered by the fluctuations in availability, price and quality of scrap iron. As a result, a search was made for a suitable process to enable HYLSA to satisfy its need for a reliable source of feed for its steel-making facilities. Their relatively low iron requirements at the time did not justify the very high capital investments required using the conventional blast furnace method. Processes which by-passed the blast furnaces were very much in their infancy and were not commercially tested. HYLSA then undertook an investigation of the direct reduction processes, knowing full well that much larger companies in other countries had investigated several processes but their work had not established a trend toward direct reduction or any particular process. However, after much effort and persistence HYLSA arrived at a process which suited their conditions. By using Mexican iron ore and natural gas they developed the now well-known H. y L. Process to produce sponge iron. Concurrent with the start of investigations which led to the H. y L. Process, HYLSA began an exploration program for a suitable source of iron ore. Thus in 1951, Cia. Minera Las Encinas, S.A. was formed, culminating in the development of the ore bodies near Pihuamo in the State of Jalisco. Mining commenced and ore was

Jan 1, 1971

By H. Majima

In spite of the importance of the presence of pyrite in the flotation of sulphide ores, not many studies have been made from the electrochemical point of view. It is generally recognized that the oxidation of sulphide minerals is one of the most Important factors among those which affect the floatability of sulphide minerals. The concept that the presence of oxygen is essential to the flotation of sulphide minerals is supported by numerous experimental results (1). The presence of oxygen in sulphide minerals- aqueous solution systems would affect the electrochemical behaviour of sulphide minerals and subsequently lead to more complicated reactions on the surface of sulphides. Actually some of the phenomena observed in sulphide flotation are deemed to be more appropriately explained from the electrochemical point of view. The author and co-workers have studied extensively the electrode reactions of pyrite and its significance in sulphide flotation. The results have been partly published elsewhere (2-7). In this paper, the author discusses the electrochemical nature of pyrite, and the three different phenomena observed in pyrite flotation: (1) Xanthate¬dixanthogen system on pyrite, (2) Flotation of complex sulphide ores containing pyrite and (3) Depressive mechanisms of pyrite with cyanide. The phenomenon which has been known as an iron contamination effect due to steel grinding media on sulphide flotation is also explained from the electrochemical aspect. However, this problem is not directly concerned with pyrite, and it will be discussed elsewhere (8).

Jan 1, 1971

By R. J. Lutton

Empirical data from 91 rock excavations have been used to construct a family of slope curves on a chart relating excavation height and inclination. The highest and steepest slopes from each excavation are plotted and connected by a line. The 31 1ines appear to establish one or two geometrical slope fields through which the curves are projected. The curves apparently represent a lumped eflect of many factors too complex to be considered individually. Important factors such as geological structure or ground-water conditions can dominate the picture, but where these factors do not overshadow others, the slope chart should be useful for estimating or checking optimum inclination. The U.S. Army Corps of Engineers (USAE) has been engaged since 1962 with the U.S. Atomic Energy Commission in a joint research program to develop nuclear excavation technology. The Corps is responsible for collecting the requisite data on engineering and construction problems associated with nuclear excavation. The ultimate objective is to develop a capability to use nuclear explosives as a construction tool on public works projects such as harbors and canals. The present study on empirical inclination-height curves for conventionally excavated slopes is an outgrowth of an investigation' sponsored by the USAE Nuclear Cratering Group on applicability of data from existing excavations in establishing guides for engineering judgment in crater excavation. Data were generously contributed by over 50 mining companies among other organizations. Inasmuch as several companies preferred that their contribution be anonymous, all data are treated so here. Some Factors Affecting Stability Many factors affect or are suspected of affecting the stability of excavated slopes, e.g., adverse structural orientation, degree of structural ordering, ground water, climatic conditions, mechanics of excavation, and plan-profile configuration. Such factors are lumped together in developing a slope chart. Obviously geological structure and ground water can overshadow all other factors. Where such is the case, the simplification of slope charts may give an erroneous picture (not conservative enough). A further complication results from the fact that the concept of stability may vary according to the use of the excavations. For example, slope adjustments that would be regarded as failure in a powerhouse excavation, might be tolerable in a mining operation. Mine slopes are continually being modified by further excavation, and instability that would develop in a similar permanent excavation slope over a period of years might not have time to develop in a mine. Inclination vs. Height Charts Charts of inclination vs. height for particular formations or conditions have been used in the past as an aid for designing excavation slopes. Some of these have been based upon empirical analyses of collections of data and experience. MacDonald" and Lane have presented slope tables and charts for excavated and natural slopes in relatively weak sandstone and shale. Coates' has shown an inclination-height chart for slopes in incompetent rock. Most organizations have developed slope design criteria which relate bench widths, heights, and inclinations to use in various rocks. Slope data collected in present studies can be similarly used to develop inclination-height charts; however, a plot of all slopes on such a chart shows very little because of the wide spread of the data. Reasons for the dispersion of points are: (1) many slopes are not carried at optimum inclination, particularly in mines where maintaining roadways and following irregularities of ore bodies are more important than achieving steep inclinations; (2) many engineers and geologists with varied backgrounds and viewpoints have been involved in designing these slopes; and (3) each slope is characterized by a unique combination of factors affecting stability and in turn optimum inclination. Significant curves can sometimes be constructed where the points can be grouped into related clusters from the same excavation. The essence of this approach appears when only two slopes from each excavation are considered—the highest slope and the steepest slope, connected by a line segment (Fig. 1). This reduces considerably the usable data because in many cases only one of these two slopes is available. Nevertheless, the concession seems justified. Construction of Slope Curves Ninety-one pairs of points and connecting line segments were assembled in this study. The line segments were assumed to approximate a geometrical slope field (Fig. 2), and a family of curves has been visually projected through to represent the slope field. It should be

Jan 1, 1971

By N. Sheikh

In galena flotation, lead ethyl xanthate, Pb(EtX)2, is precipitated and is physically adsorbed in the form of multilayers on the chemically adsorbed first layer of Pb(EtX). 1,2) The solid particles are coated with layers of Pb(EtX)2 in heterogeneous manner over surface areas possessing both anodic and cathodic character (3,4) It is anticipated that the mode of formation of Pb(EtX)2 and the number of ions present, together with stable or unstable by-product species, have great influence on the surface characteristics of galena. The information obtained from a study of these parameters may have important practical applications in flotation. Lead ethyl xanthate is sparingly soluble in water. The metal and xanthate ions released to the aqueous solution during its dissolution undergo various types of reactions depending upon the pH values of the system. Extensive work (5,6) has been carried out to elucidate the mechanism involved in acid decomposition of xanthate ions. Different decomposition paths (7,8) have been proposed for the hydrolytic decomposition of xanthate in neutral and alkaline solutions, The concentrations of lead ions vary due to a number of chemical reactions, regulated by the pH and the temperature of the bulk phase. The hydrophobic character of Pb(EtX)2 may change with the nature of chemical reactions. Some of the numerous by-product species in solution may adsorb on the solid and change the properties of surface film either favourably or adversely. The flotation performance of galena, therefore, may depend to a considerable extent on the physical and chemical stabil¬ity of Pb(EtX)2 layers. Since little work has been reported in literature dealing with the stability of Pb(EtX)2 and its correlation with the flotation of galena, attempts have been made In this study to evaluate the behaviour of freshly formed Pb(EtX)2 in aqueous systems at various pH values.

Jan 1, 1971

By Wayne E. Glenn

A centennial meeting should be a time to take stock, to evaluate performance, to plan ahead. It is like a line in a televised commercial that goes, "You've come a long way to get where you've got to today." And no less should be said of the mining and energy industries. We have come a long way. A hundred years ago when AIME was founded, this country produced 23 million tons of bituminous coal and 5.2 million bbl of oil. The figures in 1970 were about 580 million tons of coal and 4.1 billion bbl of oil. In spite of such accomplishments, serious and compelling voices are heard in the land - doubting sincerity, questioning corporate structures, and challenging ethics. Those doubts are raised in one part of Washington at the same time that other sections of the Capitol are asking us to produce more energy in order to keep up with population growth, emerging nations, and new technologies. Those of us in the fuel or energy business frequently talk about the race for energy. The question is, can we develop enough energy fast enough to outdistance our present and increasing demands? Recently I heard of an incident that - in an odd way - caused me to think of the energy race. The incident involved a sky-diver who jumped from an airplane without a parachute. He was handed a chute in mid-air by a sky-diving companion. He put it on, opened it, and landed safely. In a way, it seems to me that our society is hurtling through space and that it needs some help from the energy industries to land safely. We're doing our best, but under some rather difficult conditions. Because of illegal strikes and work stoppages the coal parachute is snarled a bit. The cut in percentage depletion and other tax changes have put some holes in the oil parachute. And the gas ´'chute has been in trouble for some time because of unrealistic controls on producer prices. The irony of the situation is that some of the very people who have been taking potshots at the energy parachutes for a long time are the ones who are complaining loudest now because the 'chutes are not functioning the way they could. The safety of the entire nation can depend on the energy industries.

Jan 1, 1971

By Otis M. Clarke

The Eufaula bauxite-kaolin district in southeastern Alabama is an important source of raw material for the refractory industries in the United States. At the present time, five companies are mining and processing bauxite and kaolin from this district and a sixth company is holding substantial reserves. Mining operations are expanding, but finding new ore reserves is a major problem. The Geological Survey of Alabama sponsored geologic research in the Eufaula district to: 1) investigate the utilization of sandy kaolinS and other clays associated with bauxite-kaolin deposits; 2) find limits of the bauxite district, looking for possible extensions; and 3) study the geology of the district, looking for patterns or trends that may aid in finding new ore reserves. This work was done with the full cooperation of mining companies operating in the district and property owners. Research was aided by the U.S. Bureau of Mines and the University of Alabama. The investigation included detailed geologic mapping of mines, drilling in selected areas, and making mineral analyses of bauxite and clays. The mapping was performed primarily by pace and compass because of the complexity of the deposits studied, but aerial photographs were used to a limited extent. Drilling included both auger and core drilling. The auger drilling was limited to 100 feet, but core holes were drilled as deep as 200 feet. The term 'bauxite,' as used here, indicates a mixture of minerals containing more than 50 percent gibbsite. Bauxitic clay is a mixture of gibbsite and kaolinite that contains more kaolinite than gibbsite. The term "kaolin" indicates a clay composed of predominantly kaolinite. Other clays in the Eufaula district are composed of kaolinite, illite, quartz, mica, and goethite or hematite.

Jan 1, 1971

By John V. Beall

Our moment of truth is in the offing. When the SME Directory is published in this July issue of [8:] we will know how good or how bad our system is for this computerized Directory. At this writing we have not seen the printout. The SME Directory is designed for maximum utility by the membership but this, of necessity, makes the job complicated. In the alphabetical section, names are listed last name first, followed by codes indicating the class of membership, year of election and divisional interests of each Member. This information is followed by job title, company division, company name and address complete with zip code, or simply by the mailing address of the Member in cases where he either has no company or has not supplied the company information.

Jan 1, 1971

By Gordon L. Draeseke

"Before getting into more specific aspects of my talk today I should put in one disclaimer - one week in Mainland China and one day with Premier Kosygin does not make me an expert on Sino-Soviet affairs nor on Canadian-Chinese relations. Perhaps though there is a message in the fact that one meeting took place in relative openness in China and the other was at least partly in a bullet-proof limousine in Canada. I thought it might be interesting and appropriate to explain something of the forest industry to you who are engaged in the mining industry. Our industry, like yours, is based on a natural resource and the basic activity that we engage in is the extraction and conversion of that resource into saleable materials. However, the fundamental difference between our industries is that our resource is on top of the ground - easily visible and easily measurable, whereas yours is under the ground - difficult to find and, having been found, expensive to measure. A second difference is that ours is renewable while yours is extractive, and you must keep finding more to keep up reserves."

Jan 1, 1971

By Laszlo Valentyik

Heavy media separation (HMS) is one of the most widely used gravity methods in the mineral industry. The feed is separated, according to the specific gravities, into two products; float (light) and sink (heavy) particles. The universal acceptance of the process is due to simplicity, efficiency and robustness for ease of control. However, if optimum separation is desired during the operation of heavy media plants, a delicate balance of a number of variables is essential. Among the variables, the two which are generally the most frequently checked and controlled are specific gravity and consistency of the medium. The latter is a function of the settling rate of the media. The medium is generally made up of finely ground ferrosilicon, magnetite, galena, shale, quartz sand, clay contaminants and water. The frequently present clay in the medium acts as a stabilizing agent, since the coarse heavy medium solids (called media) would quickly settle if they were mixed only in water. Clay concentration of the medium varies between 3-7% by height (1,2). Although clay is essential for reasonable media stability, clay concentration greater than 7-8% imparts too high a viscosity to the medium, and the feed cannot accurately stratify and therefore separate into the required products. To be on the safe side, plant operators clean the medium from most of the clays, and would rather work at a lower stability than have a very viscous medium on their hands. The most recent advance in the area of consistency control rlas made by the introduction of atomized (spherical) ferrosilicon (3). This extended the upper limit of the use of ground ferrosilicon from 3.3 to approximately 3.6, broadening the range of the optimum operating conditions. A viscosity control method was also worked out by the use of low cost additives which lower viscosity while retaining a favorable low setting rate (4). Recently (5) polymers have been successfully used in oil well drilling muds then the requirements were mainly to suspend and transport cuttings during the periodic shutdowns and dril1ings respectively. The rheological properties of these polymer suspensions are such that they present an infinite viscosity to

Jan 1, 1971

By James M. Winston

When I began my career (the first assignment was mucking the "drainage" ditch) an experienced miner told me, "Remember son, happiness is a journey, not a destination. . . ." If you missed the 100th Anniversary of AIME in New York this year, you are missing the journey. There are not enough superlatives to describe the event. Especially since New York is "known to have it all." An Indefinable Plus There was a little something different at this meeting. I cannot explain what, but there seemed to be more of everything. There were more wives there this year-what a pleasure to see all the lovely women mingling through the conference- which was reflected through our own attire and mannerisms. In fact, everyone looked so great, we checked to see if it really was a convention of miners. You wives keep coming to all of the events, because so much is added by your presence.

Jan 1, 1971