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By S. Frimpong, G. Galecki

Dump truck tires are often used in long-haul roads in rugged terrain, with high rolling and grade resistances. These conditions increase the ton-kilometer-per-hour (tkm/hr) or short-ton-mile-per-hour (stmph)rating of tires, leading to tread wear, cuts and complete failures. The load-bearing capacities of these tires are sometimes exceeded, with truck overloading, overstressing, heating and subsequent failures. In addition, truck tire demand far exceeds the current supply capacity, with long lead ordering time. This condition has caused severe tire shortage, and the problem is expected to be sustained in the long-term. Industry has taken extensive practical measures to prolong tire service life with significant results. However, this problem can be solved through fundamental and applied research initiatives. This paper pioneers a research effort in tire service life using multibody physics, fatigue failure modes and soil failure dynamics to develop tire-road contact force dynamics. A virtual prototype simulator of the tire-road contact, using the CAT 775E (with standard tire 24.00R35) was developed and simulated within the MSC.ADAMS/NASTRAN environments. The results show the areas of the loaded tires with maximum Von Mises, principal and shear stresses, which could result in fatigue failure, tire wear and tear and blowouts. The maximum Von Mises stresses on the six truck tires are between 35 and 58 MPa. The maximum shear stresses are also between 19 and 33 MPa. These stresses will cause early tire failures given an average operating schedule of between 20 and 24 hours per day. The isolated areas with maximum stresses will be subjected to further studies to reduce stress intensity while preserving tire performance.

Jan 1, 2012

By Franklin H. Sharp

During the last few years the New Lead Belt of South- eastern Missouri has become the main source of lead in the United States. It also produces significant amounts of zinc, copper, and silver. The mines are located on a narrow, mineralized trend extending southward from Viburnum, Missouri for about thirty-five miles. The area is part of the Ozark uplift and consists of steep-sided, heavily wooded hills with narrow valleys. Surface streams are very erratic, normally having low flows but becoming rushing torrents during the violent thunderstorms that occasionally occur. Because of the pristine nature of the country and the newness of the mining developments, the environmental impact of all phases has been closely watched.

Jan 1, 1973

By D. L. McCain

The movement of solids by pipeline is an art dating back well over 100 years as evidenced by many references in the literature. Even though all of the early pipeline transport systems were based on trial and error and relied mainly upon the designer's experience, hydraulic transport offered distinct advantages in convenience or cost for the chemical, mining, and civil engineering industries. It became well established for in-plant process lines, dredging, waste disposal, and other uses almost exclusively for short distances. During more recent times, much research work has been done in an attempt to understand the underlying principles involved in transporting solids in a fluid. Design criteria for pumping slurries have evolved to the point where pipelines designed for distances of several miles to several hundred miles can be accomplished successfully. Consolidation Coal Company designed and built a 10-inch diameter 108-mile long line1 for transporting coal in the 1950's and operated it from 1957 to 1963 when it was placed in mothballs because of falling freight rates for rail shipment. More recently, the 273-mile Black Mesa Pipeline2 was built and is operating. There are other examples of long distance pipelines,3 but all are for specially prepared fine slurries which allow the pipeline to be operated more economically.

Jan 1, 1975

By J. A. Procarione

Introduction Ventilation engineers have always felt somewhat uneasy when, in the normal course of their work, they are forced to consider the flow in any mine entry as "wholly rough." Under such conditions in pipes, friction factor is no longer a function of Reynolds' number. This assumption serves to simplify the problem and overcome an evident lack of information concerning the variability of K-factors. During the summer of 1985, a unique opportunity to investigate the reaction of friction factor to changing flow rates presented itself. A Utah coal mine was temporarily directing a substantial airflow through a single entry. By regulating the quantity, it would be possible to obtain a wide range of Reynolds' numbers in an entry composed of two distinct coal thicknesses. This paper describes the conducted study. The theory covering basic fluid flows in pipes that led to the questioning of constant K-factor is presented first. Experimental procedures are then described, including the use of a view camera in determining entry area and perimeter. Finally, a discussion of the observed variations in friction factor versus Reynolds' number is given. Changes of 34% and 45% in K-factor were seen in this study for the two entry heights. The implications of ignoring the relationship in this case and a call for an expanded research effort are also presented. Theory Since a gas is a fluid, the general principles of fluid mechanics are equally applicable to airflow in a mine entry as they are to the flow of water in a pipe. The Darcy equation is, therefore, equally applicable to pressure drop calculations in both situations. This famous formula was originally derived for use in circular cross sections and may be modified for any other shape by the use of hydraulic radius (defined as the area divided by the "wetted" perimeter). The Darcy equation relates the physical parameters of the pipe (diameter, length, and resistance to flow) and fluid velocity to the energy needed to create the flow. A study by Nikuradse (1933) brought to light the suspected dependency of the friction factor term in the Darcy equation upon Reynolds' number. By performing a large number of laboratory experiments, he established some basic concepts upon which other researchers built. Chief among these contributors was Colebrook (1939). Using commercial-grade pipe, he established an empirical relationship between Darcy's friction factor and Reynolds' number that is still in use today. If Colebrook's system of equations is plotted on log-log paper (as was done by Moody, 1944), the curves have some very distinct features. Of importance to the subject at hand is the relative response of friction factor to Reynolds' number at a given relative roughness. Simply stated, a pipe can appear to be either smooth or rough, depending on the flow conditions. As the Reynolds' number increases, the friction factor decreases at a decreasing rate until it becomes nearly a constant value. At this point, the flow is said to be "wholly rough." It is upon this condition that many traditional ventilation solution methods depend. For calculating pressure drops in a mine entry, Atkinson's equation is much more popular than the Darcy equation. Both of these formulas describe the same phenomenon and so have similar forms and functions. The K-factor in the Atkinson equation is equivalent to the Darcy friction factor and can be related by simply changing units, equating the pressure drops, and canceling like terms. A generalized form of this relationship is presented below as equation 1. K = yf/28,800g = [q]f/28,800 (1) where K is Atkinson's friction factor in kg/m3 (lb - min2/ft4), Y is the specific volume in Nt/m3 (lb per cu ft), p is the fluid density in kg/m3 (slugs per cu ft), g is the acceleration due to gravity (9.8 m/s2 or 32.2 fpsz), and f is Darcy's friction factor, which is unitless. The objective behind Eq. 1 is to show the strong correlation between K and f. Since these two quantities differ only by a constant (q]/28,000), the assumed independence of K-factor and Reynolds' number is suspect in light of the known response of f. Unfortunately, the formulation does not provide information concerning the actual relationship, as entry geometry likely plays a major role in the response curve. Only an indirect indication that such a relationship might exist is provided. Previous work on this subject was performed by Thomas Falkie (1958). The study involved a laboratory model composed of sections of straight, steel duct and a range of Reynolds' numbers from 15,610 to 137,200. Results from this work show a variation in friction factor with Reynolds' number in much the same way as it was found to vary in pipes. Over the range of velocities examined, a decrease of approximately 38% in K-factor was observed. This previous experience provides additional incentives to investigate the phenomenon under field conditions. Past model studies done at the University of Utah by Ozukurt (1945), Biron (1944), and Greenhalgh (1942) present similar evidence of this variability. More recently, Kharkar's (1974) study of coal mine friction factors contains similar indications that K-factor is not constant in all situations. Taken together, the data

Jan 1, 1988

By Colin D. Jardine

Rapidly increasing energy costs and more rigid customer quality requirements necessitate improved control of pelletizing processes. With the introduction of dedicated microprocessor-based controllers, sophisticated control strategies are now possible. A recent application of this technology at Carol Project has resulted in fuel savings, improved pellet quality, and standardization of operating procedures. This was accomplished with no production loss by the use of a "building block" approach to design and equipment selection. Details of this approach and the results obtained are described.

Jan 1, 1982

By Bruce H. Mason

Lightweight aggregates are classified as those minerals, natural rock materials, rock-like products, and byproducts of manufacturing processes that are used as bulk fillers in lightweight structural concrete, concrete building blocks, precast structural units, road surfacing materials, plaster aggregates, and insulating fill. Other uses include architectural wall covers, suspended ceilings, soil conditioners, and other agricultural uses (Mason, 1989). One unusual agricultural use recently reported was for bedding on a crocodile farm on the south coast of Natal. It seems that female crocodiles became upset because there was no vermiculite in which to lay their eggs due to the late arrival of a consignment of vermiculite. The vermiculite was being used as a substitute for river sand to nest crocodile eggs (Griffiths, 1989). The various lightweight aggregate materials may be classified into four groups as follows: 1. Natural Lightweight Aggregate Materials-prepared by crushing and sizing natural rock materials, such as pumice, scoria, tuff, breccia, and volcanic cinders. 2. Manufactured Structural Lightweight Aggregates-prepared by pyroprocessing shale, clay, or slate in rotary kilns or on traveling grate sintering machines. 3. Byproduct Lightweight Aggregates-prepared by crushing and sizing foamed and granulated slag, cinders, and coke breeze. This group of lightweight materials, with the exception of slag, has become less significant and will not be discussed in this chapter. Other lightweight aggregates are beginning to appear in the marketplace. Some are the result of manufacturing processes on industrial byproducts and/or waste products, such as fly ash and incinerator residue (Bigner, 1992). 4. Manufactured Insulating Ultralightweight Aggregates-pre- pared by pyroprocessing ground vermiculite, perlite, and diatomite. The application of diatomite in brick and in extruded and aggregate forms has declined in recent years (Kadey, 1983) and will not be considered in this chapter. Lightweight aggregates for structural concrete and concrete masonry units, according to the American Society for Testing and Materials (1986) consist of "aggregates of low density used to produce lightweight concrete, including: pumice, scoria, volcanic cinders, tuff and diatomite; expanded shale, clay, slate, perlite, vermiculite or slag; and end products of coal or coal combustion" (Mason, 1989). Lightweight aggregates are distinguished from other mineral aggregate materials by their lighter unit weights-1 281 to 1 602 kg/m3 or less for loosely packed lightweight aggregates-as com- pared to 2 002 kg/m3 or more for crushed stone, sand, gravel, air-cooled slag, and other common mineral aggregates. The specific gravities of these lightweight aggregates are also used to classify them for use in concrete; they range from the extremely light materials, used for insulative and non-structural concrete to expanded shale, clay, slate, and slags used for structural concrete. Vermiculite and perlite are sometimes referred to as super light- weights. Insulating concrete (non-load bearing) weighing as little as 240 kg/m3 can be made with these aggregates. Natural aggregates such as pumice, pumicite, and scoria are normally made into concrete weighing about 400 to 480 kg/m3. Expanded shale, clay, and slate produced in a rotary kiln make structural concrete ranging from 1 201 to 1 842 kg/m3. Expanded shale and clay produced by sintering make concrete that ranges from 1 442 to 1 922 kg/m3. Air-cooled slag produces concrete ranging from 2 162 to 2 403 kg/m3. The low density lightweight aggregates are used primarily for insulating purposes. They have relatively low compressive strength. The middle density aggregates are used for insulation and for fill. Those at the upper end develop excellent compressive strength and are used in many structural applications (Anon., 1971). In recent years, the production of lightweight aggregates in the United States for all uses (including insulation and construction materials) has averaged about 19 Mtpy (Table 1). The production and consumption of lightweight aggregate is closely tied to the fortunes of the construction industry and the need to construct energy efficient buildings. Recent years have seen the production of lightweight aggregate approach the levels of the early 1970s. The period of 1979 to 1981 was a low point in production levels. The low levels of production were caused by significantly higher plant energy costs due to the large amounts of fuel and energy used in the production of most types of lightweight aggregate. Lower levels of construction activity also affect production levels. This chapter focuses on the use of natural lightweight aggregates and manufactured insulating ultralightweight aggregates, and on both the production and use of manufactured structural light- weight aggregates. Some additional comments are made on byproduct materials. Separate commodity chapters on vermiculite, perlite, pumice, and volcanic cinders are elsewhere in the volume. Discussion of the commodities covered elsewhere in the book will be limited to observations on their utilization and relation to other lightweight aggregate materials.

Jan 1, 1994

By B. K. Parekh

The International Symposium on Comminution was organized at Camborne School of Mines, Cornwall England. Papers covered the fundamental and practical aspects of comminution in the mineral industry. Although comminution equipment design has not changed fundamentally during the last 50 years, methods of control and optimization have improved considerably. A simulation model for batch ball milling in the rotating mill was developed as a step toward continuous simulation of ball and autogenous milling. New concepts in jaw crusher technology design and the concept of a 1.6- x 2.1-m (66- x 84- in) jaw crusher with open feed throat has resulted in power savings. The use of cone crusher technology in comminution circuits with particular reference to machine design, plant flowsheet and control figuration has been reported by Boliden Allis, of Sweden. The Whiten steady state crusher model form has been used to develop a quantitative model of 2.1-m (7-ft) cone crushers. This was done by incorporating liner age (wear) and liner length as variables on the selection of particles for breakage and thus on the product size distribution. Another paper by Lira and Karetsky discussed the development of a model based on a multisegment ball mill developed by Whiten and Kavetsky. It is capable of simulating the performance of a coarse grinding ball mill of a given diameter, ball size and mill speed.

Jan 1, 1991

By Ehsan Nasiri, Keivan Pak Iman

Historically, boulders are a frequent source of problem in soft ground tunneling. It is important to attempt to make an assessment of the nature and quantity of the boulders, although in many cases, it will be impossible to do so with great accuracy. Boulders, can pose major problems for TBMs in terms of slowing down or halting the tunnel advance, cutter damage, and abrasive wear. Although proper selection of the TBM and the cutterhead can reduce the risks, ground uncertainties still cannot be eliminated. The paper reviews a case study of a 3480 mm diameter EPB-TBM in Toronto utilized for completion of 2.5 km tunnel in Glacial Till, crossing the CP railway, HWY 401, a creek, and a confined aquifer. Alignment consists of multiple horizontal curves including small radius curves (r=210 m) at shafts breakthrough. An unexpected boulder cluster lead the contractor to experience extreme damages to the screw conveyor, RFJ system and causing a crack in main motor plate which resulted in losing one of the six main motors. This paper reviews contractor’s solutions and includes discussion on specific claim resolution method used in this project that can be of great value in preparation of specification and GBR for similar projects.

Jun 13, 2021

By W. A. Hoyer

Neutron activation analysis for mineral identification has attracted the attention of numerous investigators, judging from the publications on this subject in the past few years. 1-9 The appealing aspect of this method of mineral analysis is its proven sensitivity in the laboratory. In principle, activation analysis is one of the few petro-physical methods whereby a direct analysis for a mineral itself is possible in a borehole. The successful application of activation analysis requires the use of particular neutron reactions, measurement of selected gamma-ray energy intervals, and optimum bombardment and detection times. For copper analysis, Labanov et al., 10,11 using a low-energy PuBe source, reported an acceptable logging means. On the other hand, Pradzynski12, in analyzing ores and process tailings, used high-energy neutrons and photons for surface measurements of process samples. The work of Labanov et al. was based on measuring the rate of decay of the activated copper and hence was not as definitive as might be desired. Equipment is commercially available to carry out activation studies in the field 13,14 Gamma-ray spectra can be successfully transmitted over ordinary logging cables and, with borehole high-energy neutron accelerators and lower-energy chemical neutron sources, a variety of neutron activation methods can be studied. The purpose of the study discussed in this paper was to determine the feasibility and practicability of logging for copper using neutron activation techniques and commercially available equipment. The laboratory study showed that Cu could be detected in rock samples in the laboratory by high-energy neutron activation of 63 Cu. In the field, however, due in part to the large volume irradiated, the direct detection of copper using high-energy neutrons was not as promising. Detection of copper by measuring both the direct gamma-ray emission and the excessively strong low-energy gamma-ray absorption appears promising. Copper was not detected either in the laboratory or

Jan 1, 1972

By Robert E. Frey

Regardless of the mechanical design features of a particular air classifier certain basic principles apply. Specifically , there are two forces at work: 1. An air drag force 2. An inertial or centrifugal force. The air drag force has an increasing influence as particles become smaller. A very small low mass particle is easily carried along with an air stream even when turning a corner. Thus, fine particles follow the air away from the classifying zone. Inertial forces increase as the mass of a particle gets larger. Thus oversize particles tend to obey Newton's laws and respond to centrifugal forces or simply continue in a straight path when the airflow changes direction.

Jan 1, 1985

By C. J. Weiss

"A commercially available Through-the-Earth (TTE) communications system was evaluated at an underground coal mine in eastern Kentucky. This field study was conducted as part of a larger multi-site evaluation of available TTE systems to determine their operational sensitivity. Field testing is being performed along with simulation techniques developed for geophysical surveys. The results of the field test will additionally be used to determine the applicability of these simulation techniques to TTE communications. The mine detailed in this paper was idled at the time of the study, which provided the nearest practical representation of a post-event mine shutdown. For this study, the three following communication modes were tested: surface-to-underground, underground-to-surface and surface-to-surface. Standard deployments of the TTE system using the manufacturer’s recommended procedures were able to achieve clear communications between underground and surface locations. Other arrangements of the units yielded intriguing results, some of which were predicted by computer simulations, others were unexpected. Future experimentation is planned to further evaluate the observed phenomena. INTRODUCTION The ability to establish effective communication between surface and underground personnel after a mine event is essential for both mine evacuation and mine rescue efforts. Current communication technology is reliant on physical infrastructure, such as antennas, cables, and repeaters, located throughout the mine. Such systems are easily disabled during a mine event because of their vulnerability to physical damage. A true emergency communications system would have the ability to function regardless of a mine’s physical state. Through-the-Earth (TTE) wireless communications technology has the potential to provide such a tool. Wireless TTE communications are exceptionally challenging because electromagnetic (EM), or radio, signals are subject to drastic attenuation as they travel through solid strata. In addition to attenuation, EM wave propagation is directly affected by the physical and petrographic characteristics, mineral compositions, metamorphic properties, and the degree of water infiltrations in the strata [1-5]. These strata characteristics are unique to each mine thus making the design of an effective, universally deployable, and reliable TTE communications system very difficult. At present, TTE technology is in the preliminary stages of practical deployment with only a few permissible TTE systems commercially available."

Jan 1, 2015

By Courtney Chamberlain

The Telfer Project, Australia's newest, largest and most remote gold mine, treats 480,000 metric tonnes of ore grading 9.33 grams per tonne derived from open pit mining operations. Coarse gold is recovered by gravity concentration with jigs and further upgraded using a continuous strake, table and by amalgamation. Remaining gold is recovered in a cyanide circuit and incorporates flat bottom air agitators, CCD and stellar filters for clarification and precipitate removal. Overall recovery into bullion averages 98 percent. The mill incorporates a number of design features which allow for maximum efficiency and security using a minimum number of operating personnel.

Jan 1, 1980

By Diómedes Sarmiento

Centromin is a Mining Company owned by the peruvian government. It's considered as one of the major mining and metallurgical center in Latin America. The main operations of the Company are: Mining, Concentration, Smelting and Refining of several metals (Figure 1). At present, dentromin operates with six mining units: Cerro de Pasco, Morococha, Casapalca, San Cristobal, Yauricocha and Cobriza; which are located in the Central part of the country between 2 100 m and up to 4 800 m above sea level. The installed capacity of concentration all together ranges about 14 000 tons per day. There's also a metallurgical plant in La Oroya with a production capacity of 220 000 tons per year of refined metal. The production of the Company is diversified in twenty two (22) final pro- ducts, whose major productions are : copper, lead, zinc, silver, gold, tungg ten and bismuth. The minor products are: arsenic, antimony, cadmiun, teluriun, sulphuric acid, indium, selenium, etc.

Jan 1, 1979

By J. Richard Tonry

In portland cement manufacturing, the raw materials axe changed to clinker in the burning operation. Generally the rotary kiln is used for this purpose and involves many processes, including pelletizing and nodelizing. This transformation is called clinkering, and is analyzed as now generally practiced in cement making, from the raw material to the resulting clinker.

Jan 1, 1963

By S. C. Nordeng

The program described in this paper is primarily a test of the possible utility of multiple regression in ore search, It was carried out as a cooperative project between White Pine Copper Company, the Institute of Mineral Research and the Department of Geological Engineering of the Michigan College of Mining and Technology. The authors wish to thank Dr. Cleaves Byers, Associate Professor of Mathematics, MCM&T, and Mr. Robert DeBaubien, Graduate Student in Mathematics, MCM&T, for their work in programming the project for the computer,

Jan 1, 1964

By M. Xing, S. Usman, K. Awuah-Offei

"While mines generally focus on achieving operational efficiency, creating shared value for all stakeholders is also a management goal. This includes taking a holistic view of their supply chains and increasing local participation. This paper examines the role of supply chain management in mine management; in particular the effect of a strong local supply chain on regional economic impacts. Using input-output analysis, the impact of a local supply chain on a mining sector’s regional economic impact is examined by increasing local sourcing (increasing local purchase percentage -- LPP) for 10 key commodities. An approach, based on multipliers and excess local capacity is used to identify key commodities. The impacts examined are sales, employment, labor income, and value added. The work is illustrated with stone mining and quarrying in Missouri. Ten percent increases in LPP of the key commodities, in this example, result in $4.1 million additional impact on the Missouri economy. This work can provide insight on how to better create shared value for all stakeholders. INTRODUCTION Little research has been published on improving mine supply chain management (SCM) to enhance regional economic impacts. Although some extensive academic research has explored the importance of an industries’ supply chain, not much is known about how a locally-based supply chain increases shared value in the resource sector. Across industries, traditional SCM is getting more and more complex. This is true of the mining sector as well. However, this increased sophistication is not directed towards increasing shared value for all stakeholders, particularly, the local communities. Further research is required to develop new SCM strategies that enhance local participation. One major point of difference between this work and traditional supply chain management is the inclusion of stakeholders’ shared value as a goal in SCM. Creating shared value has become a business goal in recent years (Porter and Kramer, 2011). The authors use input-output analysis (Leeuw, 2012) to evaluate the regional economic impacts of supply chain decisions, which is not part of traditional SCM. Although input-output analysis has been applied to SCM for decades, most of the research uses input-output analysis as a tool to advance an industries’ own operational efficiency (Accenture, 2014)."

Jan 1, 2015

By William H. McLemore

Geologists searching for carbonate rocks suitable for chemical uses traditionally have relied on extensive laboratory testing in order to locate strata or zones that might be suitable for mining. However, when considering the significant time and costs involved in sampling and performing chemical analyses, any exploration technique whereby fewer samples and analyses are needed would be of great value. In other words, if the exploration geologist could "zero-in" on select areas, considerable time and money could be saved. In general, the major-element chemistry of carbonate rocks is determined by the abundance of the minerals present. CaO occurs with CO2 as the mineral calcite, which is the primary mineral comprising allochems, matrix and sparry cement; MgO is found in high-magnesium calcite (many calcite fossil species contain appreciable amounts of MgO in solid solution), dolomite, and chlorite; iron occurs in pyrite and in limonitic stylolites, as well as in chloritic and glauconitic clay minerals; materials containing abundant Si02 are microcrystalline quartz (chest) silt-sized quartz, and clay minerals; and Al203 is found primarily in illitic, kaolinitic, and chloritic clay minerals. The presence or absence of these minerals determines the chemical composition of the carbonate rooks.

Jan 1, 1983

By John M. Heckard

It all started with the National Environmental Policy Act of 1969, which establishes that Congress is committed to restore and maintain environ- mental quality. It directs all federal agencies to identify and develop methods and procedures so that environmental parameters and values will be given equal consideration in the decision-making process, along with economic and technical parameters. Section 102 of the Act directs, among other things, that all agencies will submit a detailed statement on: (1) the environmental impact of the proposed action, (2) any adverse environmental effects which cannot be avoided should the proposal be implemented, (3) alternatives to the proposed action, (4) the relationship between local short term uses of man's environment and the maintenance and enhancement of long term productivity, (5) any irreversible and irretrievable committments of resources which would be involved in the proposed action should it be implemented. Passage of this act has been followed by other legislation, both federal and state. The Water Quality Act of 1970 puts teeth into the previously existing Federal Water Pollution Control Act by requiring a "certificate of reasonable assurance that the activity licensed will not violate the applicable water quality standards." The Clean Air Act of 1970 requires that the Environ- mental Protection Agency establish national air quality standards, as well as standards for significant new pollution sources.

Jan 1, 1973

By F. Daviess

A requirement for geological controls during orebody modeling results from the recognition of heterogeneous geological characteristics and/or abrupt variations in orebody geometries. While purely statistical methods are often sufficient for modeling uniform homogeneous deposits, and the only recourse for many that are extremely complex, geological interpretations can be extremely valuable as controls during the modeling process. The advent of relatively inexpensive, sophisticated graphical computer hardware and software has focused considerable attention on the three dimensional visualization capabilities now available to the mining industry. Orebody geometries can be easily imported into many systems as wireframe or solid models, rendered with shading and color, rotated in space, exploded into composite parts, zoomed into and otherwise displayed to awe any audience. The requirements for an initially meaningful, accurate, geological interpretation are sometimes lost when the focus is on an apparently complex, highly resolved end product. Details of the initial data and sensitivities of modeling assumptions are not always sufficiently scrutinized. Software capabilities have extended the geopoetic license into three dimensions. The new tools, while greatly facilitating model construction and rendering, have done little to expedite basic data preparation and analysis. This paper attempts to briefly summarize the purpose and method of the construction of geological controls. The examples selected are from wire­framing and block modeling; application software processes commonly used in the mining industry today.

Jan 1, 1992

By O. E. Brown

The measurement principle of the Coulter Counter for particle size analyses is described. The application of the Coulter Counter to cement particle content and size analysis and to the size distribution of clinker from standard grindability tests are described. Methods of calibration, sample preparation and data reduction are presented. The results of the analyses obtained are compared with characteristics associated with performance showing both concordance and non-concordance of test data., Future uses of the Coulter Counter for particle size analysis in research and plant control adaptations are indicated.

Jan 1, 1960