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By Anoush Ebrahimi

Mining dilution is one of the most important factors affecting the economy of mining projects. Ore losses and dilution are present at all stages of mining and while several models can investigate the influence of dilution it is its quantification that poses the most serious challenge (Pakalnis et al., 1995). This paper introduces a methodology to quantify dilution factor in open pit mines. The proposed approach makes use of general mining software available in most mining companies. Therefore it is amenable to most mining operations and provides a readily available tool for understanding mining dilution for operators and consultants. To illustrate the methodology the author uses an example from a hypothetical mine. Dilution increases the operating costs in the mill by increasing the tonnage of material to be milled. In addition to its direct impact on short term income of a mine, dilution causes significant changes in other factors that on the long term reduce the overall value of the project. For example, it prolongs the mine life by reducing mill?s effective capacity. It also reduces the feed grade. In most cases, lower feed grade means lower mill recovery. Dilution also increases the cut-off grade which in turn reduces the overall ore utilization of a mine. In some cases, to take advantage of economies of scale, mining operations tend to plan for higher mining rates. Moving to a larger scale of operation means less selectivity, hence more dilution. This is true for all kind of deposits. High level and uncontrolled dilution may ultimately defeat the purpose of increasing production rates. If not impossible in theory it is nevertheless extremely difficult and expensive to eliminate dilution in practice. Some amount of dilution is practically unavoidable in most mining operations (Scoble and Moss, 1994). Although completely avoiding dilution may be impossible, we can measure and control it. By better understanding the root causes of the dilution and planning accordingly, it can be controlled and reduced. While we do our best to identify and calculate all the other cost items of a project, no matter how small, it is common to make general assumptions about dilution instead of quantifying it. It is common to assume a general dilution such as 5% for massive deposits and 10% for tabular shape deposits. While these figures may be a good starting point in early stages of mining studies, it does not take in to consideration the complexity of the problem. Dilution factor varies within a single mine for different benches and zones. This is due to changes we see in grade distribution and shape of ore body. It also varies based on commodity price. It is necessary to make sure that these variations are taken into account when designing or evaluating a mine. Dilution varies in different mines based on the deposit characteristics, operational aspects and economic cut-off grade. For instance, shape of the deposit, bench height, equipment size, and market conditions will have an impact on the level of dilution in a mine. It is paramount for mining projects to have a better understanding of dilution right from the beginning. In times like today, where mining operations must operate at peak efficiency, it is even more crucial to be able to calculate and have a better grasp of all the parameters influencing the economics of a project including dilution. In order to produce better project evaluations, dilution studies should be an integral part of any project.

Aug 1, 2013

By Gerry Norton

The purpose of this paper is to make the most complete assessment of coal cleaning methods, both process and equipment related to modern-day production and environmental requirements. In order to achieve this primary objective, a number of interdependent aspects of coal cleaning technology require evaluation and analysis. 1.0 CLASSIFICATION OF SEPARATION PROCESSES Processes and cleaning equipment can be categorized according to the important parameters of 1) mechanics of separation, 2) size range application, 3) range or variance in accuracy of separation related to 2) above, and 4) feed-size ratio affecting 3) above.

Jan 1, 1977

By N. D. L. Burger

An effective prototype face support system to minimize rockfalls in rockfall-prone mines was developed and patented during a project sponsored by the Mine Health and Safety Council (MHSC). An experimental development model (XDM) roof support unit was developed and evaluated. Mines with rockfall problems in the face areas can use the roof support system to reduce fatalities and injuries in the face area of stopes. The roof support system consists of two similar support units connected to each other via two crank mechanisms. Each unit consists of a headboard supported by a ?wishbone? structure (top and bottom leg). In the first design a threaded bar with struts similar to a scissors jack keeps the legs apart. (In the final version that was field trialed, the threaded bar mechanism was replaced with a hydraulic cylinder). All the components are manufactured from steel. To move the system forward the first support unit is collapsed, the second remaining in the loaded position. The first unit then hangs from the second unit to which it is connected. The first collapsed unit is then manually cranked forward and prestressed. If the required position is still not achieved, the other unit is released and moved forward. The specification for the system was determined and presented at a workshop with industry participants. Different concepts were developed and evaluated against the system specifications. A technology demonstrator was then developed and tested on surface. The technology demonstrator development process included detail design, building and testing of components and subsystems, design reviews and the building and commissioning of the technology demonstrator. The testing of the technology demonstrator was done in a 500-ton hydraulic press, in a mock-up stope and underground. A risk analysis, in which technical, logistical and economic aspects were assessed, was done to determine the critical areas of the system. During the next phase of the project working prototypes were developed for underground tests and evaluation. This process indicated that it was necessary to adjust the system specifications and a redesign was called for. In an iterative process test units were built for purposes of evaluation, specification verification and field trialing. After the successful conclusion of the trials the equipping of a complete production stope started for purposes of integrating the system into the current mining process.

Jan 1, 2008

By J. G. Peacey, G. Csicsovszki

The target of this study was to clarify the role of lead on the dissolution of gold in the (NH4)2S2O3-Cu leaching system via chronopotentiometry, linear sweep voltammetry and chronoamperometry. It was found that the dissolution of gold was significantly increased with lead concentration up to 10 mg/1 Pb in the system of 0.1 M (NH4)2S2O3 and 50 mg/1 Cu. \/oltammograms suggested that the anodic dissolution of gold was virtually independent of lead concentration in the range of 1-10 mg/1 in 0.1 M (NH4)2S2O3 solution while in solutions containing copper as well, addition of lead increased the anodic dissolution of gold.

Jan 1, 2011

By Joseph G. Carleton

INTRODUCTION The increasing concern for the environment may well present far more opportunities than problems for those involved in all phases of tunneling. All too frequently in the past, environmentalists and their concerns have been cast in a negative light, as obstacles to be overcome. Often forgotten is the fact that these same environmental concerns have created a rapidly increasing demand for new tunnels. Tunnels for rapid transit projects, clean water supply, and sewage treatment have been given a boost because of environmentalists' concerns about overuse of automobiles, inadequate water supplies, and improper sewage disposal. Concurrent with increasing use of tunnels to help solve or alleviate some of our environmental problems is an obligation not to create new ones in the process. Concerns which we feel responsible tunnel owners, engineers, and contractors should address themselves to include: (1) Minimum energy consumption, both during construction and in operation of the completed project; (2) proper storage and/or disposal of the excavated material; (3) minimum disruption during the construction process - noise, traffic, unnecessarily unsightly work areas, and possible weakening of foundations of nearby structures; and (4) a finished project consistent with community and environmental goals. We are especially concerned about two things. First, the longrun implications of a project -- what's good for a few people in the short-run may be bad for most of the people in the long-run. Cutting corners to save a little money now is false economy. Second, the fact that ultimately we all share the same earth -- its water, air,

Jan 1, 1974

By Dianne C. Marozas

The U.S. Bureau of Mines is conducting research to evaluate the potential for developing an in situ leach mining process that will selectively extract manganese from oxide ores, leaving gangue relatively undisturbed. To accomplish this, a geochemical approach, based on deposit-specific information such as mineralogy and geology, is used to constrain the operating parameters of the system. Among the studies being conducted are (1) leaching experiments to define reaction mechanisms and kinetics, (2) detailed petrologic characterization at the microscopic scale to assess Mn distribution and leaching efficiencies, (3) deposit characterization and evaluation, and (4) development of potential Mn recovery schemes. Data from these studies are being used to develop engineering design information for an in situ mining process. Specific details of the Bureau's research project are discussed, including results obtained to date.

Jan 1, 1991

By D. R. Willmer, E. J. Haas

"DISCLAIMER The findings and conclusions in this paper are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health. Reference to specific brand names does not imply endorsement by the National Institute for Occupational Safety and Health. ABSTRACT This study analyzed the publicly available health and safety policies of 26 mining companies to determine the quantity of health and safety (H&S) practices that mining companies encourage in relation to the Plan-Do-Check-Act cycle. A thematic content analysis of the policies identified elements and practices within the text. On average, companies communicated information on about 7 elements (range 1–14, standard deviation = 3.49) and discussed 15 practices (range 2–34, standard deviation = 9.13). The elements in which companies highlighted the most practices were risk management, emergency management, leadership development, and occupational health. A discussion of the policy trends shows areas that mine sites can improve upon within their Plan-Do-Check-Act cycle, in addition to encouraging the use of both leading and lagging indicators to manage health and safety performance. INTRODUCTION Mining companies and their employees are expected to identify and manage risks at their worksites to ensure the health and safety (H&S) of everyone at the site. The primary mechanism in place to control these risks is a company’s health and safety management system (HSMS) (Boyle, 2012). Broadly, an HSMS is a set of standard, interrelated, and interacting elements used to promote and achieve occupational H&S goals (ANSI/AIHA Z-10, 2012; BS OHSAS 18001, 2007). The practices conveyed within an HSMS are expected to minimize incidents, injuries, illnesses, and even save worker lives (Alsop and LeCouteur, 1999; Arocena and Núñez, 2010). In the United States, both the Occupational Safety and Health Administration (OSHA) and Mine Safety and Health Administration (MSHA) regulate and encourage aspects of an HSMS (US Federal Register, 2011, 2010). Many HSMS documents (i.e., Chemical Industries Association, 1995; Health and Safety Executive [HSE], 1995; International Labour Office [ILO], 2001) attribute the source of their basic management system to Deming’s Plan-Do-Check-Act (PDCA) model of continuous quality improvement and organize their practices within this cycle (Johnson, 2002). The PDCA cycle is a well-adopted approach in health and safety management and promotes continuous learning and adaptability (Robson et al., 2007)."

Jan 1, 2018

By L. Li

The rock quality designation (RQD) was initially introduced by Deere (1963) for civil engineering. But, its application has been largely extended to rock mechanics and has become a fundamental parameter in geotechnical engineering (e.g., Hoek & Brown 1980; Milne et al. 1998). The success of this definition is due, in great part, to its simplicity. However, this index includes a number of limitations. Among these limitations, a critical one is associated with the arbitrarily selected threshold value (e.g., Priest & Hudson 1976). Consequently, the RQD value would vary with different threshold length for the same core. Also, using the customarily and universally adopted but very arbitrarily selected threshold value of 10 cm (for NX cores) in the assessment of RQD, the RQD values usually tend to be either high or low in most rock engineering. Some intermediate values (50%) are less frequently encountered (Harrison 1999). The original definition of RQD does not well represent the actual quality of rock masses. In this paper, an improved definition of rock quality designation (RQDc) is given.

May 1, 2009

By Thomas A. Gwynn

"A beautiful America will require the effort of government at every level, of business, and of private groups. Above all it will require the concern and action of individual citizens, alert to danger, determined to improve the quality of their surroundings, resisting blight, demanding and building beauty for themselves and their children." "Improvement of our environment" has become a cause much like "motherhood". The increased awareness of the public concerning this subject makes it most unpopular for anyone to be involved in anything that seemingly is detrimental to our environment. And this awarement goes far beyond our biggest pollution problem in America - the distribution of paper, abandoned automobiles, beer cans and other garbage by our enlightened society along every city, highway, trout stream, river and mountain in America. In fact, the greatest awarement comes because of the "sensational" reporting and writing in our various national communication media, wherein the same voting citizens who so generously distribute their refuse about the countryside are emotionally aroused and duped into transferring what is truly a national problem onto the shoulders of a few industries - notably and particularly the mineral extraction industry. Certainly mankind is more and more stumbling over his own garbage daily, a fact that is easier to sell a citizen of one of our large cities than a resident of the wide open spaces of the west. Yet even in the Rocky Mountain states, the "Land of Sky Blue Waters", the "Big Sky Country", and particularly in Salt Lake valley smog is not unknown. Pollution and littering have become problems that need to be faced squarely. In North Dakota alone it has been estimated that one section of farm land each year flows down the mighty Missouri and the greatest producer of sediment is now reported to be the highway department.

Jan 1, 1969

In the spring of 1944 the Congress passed Public Law 290 (58 Stat. 190, 30 U. S. C. Sec. 321) "authorizing the construction and operation of demonstration plants to produce synthetic liquid fuels from coal, oil shales, agricultural and forestry products, and other substances, in order to aid the prosecution of the war, to conserve and increase the oil resources of the Nation, and for other purposes." Section 2 reads: "In order to carry out the :purpose of this act, the Secretary of the Interior is authorized- (a) to conduct laboratory research and development work, and, with pilot plants and semi-works plants, to make careful process engineering studies, along with structural engineering studies, in order to ascertain lowest investment and operating costs necessary to determine the best demonstration plant designs and conditions of operation;

Jan 1, 1948

In the spring of 1944 the Congress passed Public Law 290 (58 Stat. 190, 30 U. S. C. Sec. 321) "authorizing the construction and operation of demonstration plants to produce synthetic liquid fuels from coal, oil shales, agricultural and forestry products, and other substances, in order to aid the prosecution of the war, to conserve and increase the oil resources of the Nation, and for other purposes." Section 2 reads: "In order to carry out the purpose of this act, the Secretary of the Interior is authorized- (a) to conduct laboratory research and development work, and, with pilot plants and semi-works plants, to make careful process engineering studies, along with structural engineering studies, in order to ascertain lowest investment and operating costs necessary to determine the best demonstration plant designs and conditions of operation;

Jan 1, 1948

An Innovative Process for Comprehensive Utilisation of Clay-Vanadium Ores By adopting conventional processing technologies such as flotation, gravity concentration, and magnetic separation, it is difficult to enrich vanadium mineral effectively. At present, vanadium extraction process usually has not the mineral processing enrichment procedure, but rather uses direct hydrometallurgical process: roasting - leaching - precipitating vanadium for obtaining high quality V2O5 product. But it results in problems, for instance, high consume of auxiliary materials like acid and alkali, serious pollution and high cost of vanadium extraction. In the project study on the ore of a certain clay vanadium mineral, by adopting the test process: scrubbing raw ore with reagents added in - dispersing and segregating with reagents - grading enrichment, vanadium concentrate product with higher grade was made by virtue of reagent's selective inhibiting, and the purpose of upgrading the raw material used for vanadium extraction with hydrometallurgical process is achieved. The process technology obtained from project study features simple process structure, low equipment investment, low cost of mineral processing and pollution-free to environment. It provides high efficient and practical technology for the comprehensive utilisation of clay vanadium mineral, and has a prominent prospect for its popularisation and application.

Sep 13, 2010

Atlas Copco is one of the worldÆs leading providers of industrial productivity solutions (Atlas Copco, 2009). Furthermore, the company spans 160 markets and held 34 000 employees at the end of 2008. The company is organised under three ætechniquesÆ whereby the Construction and Mining TechniqueÆs business division is located within +rebro, Sweden. This paper is aimed at briefly facilitating information on how the company and more specifically, the Construction and Mining Technique is run. Also, by sharing my experiences, this paper is intended to encourage and motivate students currently studying for a degree relevant to the minerals industry, to apply for this extremely beneficial scholarship. Through a number of presentations relating to the various divisions, products and aftermarket services of the company, I came to realise that Atlas Copco extends beyond simply selling equipment suitable for the mining and civil industries. This tour through Sweden also contained highlights of visiting the Underground Rock Excavation factory, Surface Drilling Equipment factory and Secoroc divisions. I was also fortunate enough to participate in a tour of the LKAB mine in Kiruna. In addition, time was allocated to less industry related activities, and I was able to go dog sledging, sip vodka cocktails out of ice glasses at the Ice Hotel and enjoy traditional Swedish foods of moose and reindeer. Most important and memorable to me; however, was the ability for employees of Atlas Copco to speak of the company and their products with such passion and enthusiasm, which truly made this a motivational and unforgettable experience.

Jan 1, 2009

By W. J. D. Stone

"For several years, the existence of a deposit of barite (BaS04) near Brookfield, Nova Scotia, has been known. A very large deposit of strontium (SrS04) near Sydney, Cape Breton, is a more recent discovery. Cape Chemical Syndicate has been formed to work the deposits. A five-million-dollar integrated mineral processing and chemical plant is planned for Sydney to produce various compounds of barium and strontium. The mineral processing plant includes the Jones Wet Magnetic Separator and will produce high-purity barite and celestite. These products will be processed further in the fine grinding plant and the chemical plant. The general project is described, covering the deposits, processing and markets."

Jan 1, 1969

By Ian F. Hughes

"Concepts of an integrated steel plant for sheet products to be built and operating in the year 2000 will be described. The design and operating methodology of this market driven facility will integrate process uniqueness, standardization, manufacturing automation, artificial intelligence and information flow.An integrated steel plant for the year 2000 is defined for this article as one that will be built on a greenfield site and ""started up"" in the year 2000 with a capacity of three million tons per year of flat rolled products ranging from cold rolled and electrical steels to high strength formable steels and a full range of coated products.It may seem that the 21st century and the steel plant we're discussing are far into the future. The startling truth, however, is quite the opposite. As shown in Figure 1, even with accelerated development, a new process on which laboratory development work is begun today might just barely pass through the laboratory phase, pilot plant, and commercial feasibility stages such that it can be considered viable for construction and start up in the year 2000.On that basis, it is very unlikely that this 21st century steel plant will utilize any technology that isn't at least under investigation in the laboratory in 1988. As a result, we recognize that planning and selecting the facilities for this plant is, in fact, a pragmatic rather than futuristic process, and that its main value is in providing a bridge to longer-term predictions."

Jan 1, 1988

By Keith A. Heasley, Lee W. Saperstein

This paper investigates the use of backfill zones and yielding pillars for subsidence control. The investigation begins by choosing an appropriate subsidence predictive technique to simulate the proposed subsidence-control schemes. Two case studies are performed in order to delineate the accuracy and utlility of the chosen predictive technique and then the results of these case studies are used to establish appropriate sets of regional site parameters. Next, a detailed analysis of the major variables affecting the outcome of the subsidence-control simulations is conducted and graphical displays of the exact sensitivity of the surface subsidence to these variables are given. Finally, alterations to the surface subsidence that are expected from using two major subsidence-control techniques are presented. The first technique to be assessed is a backfilled pillar centered longitudinally in a panel. With this arrangement, a minimal amount of backfill material can produce substantial decreases in vertical displacements. The second technique to be assessed is the use of yielding gate pillars to reduce the sinuosity of the transverse subsidence over adjacent panels. With proper design, this technique can greatly curtail surface strains and help minimize remedial drainage control.

Jan 1, 1986

By S. Kelebek, E. Yalcin

"Two composite samples of a gold-bearing ore from North Western Quebec (Barry Township) were tested to assess their grindability, recovery by flotation and Knelson concentrator as well as extraction using cyanidation.Work index values (BWi) for two composites were found to be 10.4 and 11.0 kWh/tonne, respectively. Flotation tests involved feed samples for which the particle size ranged from a P80 value of 205 ?m to 53 ?m, which resulted in gold recoveries of 91.8% to 95.8% (at gold grades of 130 to 140 g/tonne). Cyanidation tests indicated gold extraction levels ranging from 94.2 to 97.5%. Higher, recoveries were obtained at finer grind sizes and higher cyanide strengths. However, the grind size had a bigger impact on gold leaching. Gold grade and recoveries obtained with the Knelson concentrator device were lower than those obtained by flotation. Mass recoveries to concentrate products strongly depended on the fluidization pressure used. High gold recoveries can be obtained generally at low water pressures of 3 to 4 psi. Higher water pressures produced more selectivity at the expense of higher gold losses.It can be concluded that the gold ore samples tested have good characteristics due to moderate levels of energy requirement, high gold recoveries and extraction rates attainable.INTRODUCTIONBench scale testing of ore samples is an important step in the long series of metallurgical and economic studies involved in bringing new ore bodies into production (Coleman, 1980). Through a laboratory testing program, the behaviour of an ore in a particular process on a larger scale can be established. In an exploratory manner, this testing can be helpful for classification of ores in terms of “good ore” or “problematic ore” by providing preliminary information on recoverability of target minerals. Potential problems if any can be assessed by further investigation of products (e.g., middlings) obtained as a result of testing. A detailed bench scale experimental program in the metallurgical laboratory can also provide the background work for flowsheet development. Depending on the simplicity or complexity of the ore to be tested and type of details required from a testing program, the amount of samples required in the mineral processing laboratory can vary from several kg to more than one hundred kg depending on how detailed the metallurgical testing program is."

Jan 1, 2008

By Russell L. Wood

The title of this session seems to have been picked especially for this paper. It is 1984, it is the morning after, and there is one monumental hangover among many if not most of the oil companies that have invested in mining in the past decade or so. How an oil company looks at mining depends on what time period you are talking about. A few years back around the time of investment this is what they were probably looking at: 1. A balance sheet of their own that was beginning to go wild, with many of their commodity prices having already seen increases of two, three, or four fold, and with no end in sight. 2. A need to invest their earnings someplace fast before the stockholders or the government got too interested. And that someplace should be in an industry where their own management skills could be applied. (Only a true cynic would suggest that this is a form of job security) 3. In mining there was an industry amazingly similiar to their own, one working with non-renewable natural resources, dealing with the same types of government agencies, and having the same type of critics and pressures from the general population. 4. An industry that was somewhat backward as compared with their own, and one where a generous ration of the capital and management skills so handsomely bestowed upon the oil industry could be used to great advantage.

Jan 1, 1984

By Dan Jackson

9:00 a.m., June 28, 1983 MR. MORTENSEN: Good morning ladies and gentlemen. Again, it gives me great pleasure to welcome you to another session of the 79th meeting of the Rocky Mountain Coal Mining Institute. The thing again that has always been impressive are the activities that we've had so far. The success in the meetings has been delightfully encouraging to all of our committee people. Please welcome the chairman of the session, Charlie Margolf. MR. MARGOLF: Thank you, Vernal. Good morning, ladies and gentlemen. It would be my privilege to serve as the session chairman this morning. To allow the maximum time for our speakers, I'll turn the microphone over to Bernie Bernstrom who will introduce our first speaker. MR. BERNSTROM: Thank you. As Vernal mentioned, Dan Jackson will be our first speaker. He is the Western Editor of Coal Age Magazine. Dan really doesn't need an introduction to this group. He's belonged to the Rocky Mountain Coal Mining Institute about 25 years. Dan is a native of West Virginia and he's an ex-coal miner. He graduated form West Virginia University as an electrical engineer and worked for Amherst and West Bending Coal prior to employment by Coal Age Magazine. Back in 1972 Coal Age moved him to Denver from New York City. MR. JACKSON: When Vernal Mortensen asked me speak to the members of the Rocky Mountain Coal Mining Institute earlier this year I found it impossible to say no to the guy because of what he has contributed to western coal. Little did 1 know that the subject he had in mind would be entitled, "An Outsider's View of Western Coal." At first I asked myself-I've been associated with the coal industry for some 38 years, 12 years in national operations and 26 years reporting on it. You might say that I've been married to two industries, coal and the business press for 26 years, but today I'll put on my business press hat and try to make an impression of what an outsider might think of western coal. But at the outset, let's get one thing straight: When you say press, whether it's business press, the media or whatever, and you heard some comments yesterday as far as what the media has done .to this industry and there's been some definitions bandied around as to just what an editor is. One of the most recent ones has defined an editor as a person who can talk on any subject with an open mouth. Now that's not my case. Secondly, I don't give long talks. Several years ago I was giving a rather lengthy talk to a group similar to this and it was halfway through the talk when I noticed one guy on my right looking at his watch quite frequently. I didn't mind that too much because all of us do that once in a while, but when he looked at his watch, took it off and shook it, I thought, "My God, better cut short." But for more than a decade western coal has enjoyed substantial annual increases in production from some 30,000,000 tons in 1970 to some 264,000,000 tons in 1981, but 1982 was a different story. We lost about 6,000,000 tons of production in that year. In 1983 it's expected to be a little worse than '82. Coal historically doesn't rebound from a recession as quickly as other industries. It takes about eight to 10 months longer for us to really get moving again and I'm afraid that you'll still have to don your fighting helmets and flack jackets when you go out into the market to sell your product. Western coal, as you know, has problems and al l of them are not going away when the recession ends and they won't go away overnight. I'm sure most of you are aware of what those problems are. Carl Bagge and Jim Harris, along with other speakers, at this meeting have educated us well on those problems and I'm sure you'll hear more from Jim Watt at today's luncheon. If everyone in this room were asked to list three orfourof the most serious problems facing western coal, I'd make book that the total of the answers wouldn't vary by more than 3 to 5%, if that much. But coal is not the only mining segment in the U.S. with problems. Metal and non-metal mining has its share, too. I'd like to step back into the past for a few minutes, if I may, to a time when our problems were just beginning. Since 1979 a third of the nation's mines, including coal, metal and nonmetal have been shut down. The total volume of all mining in the U.S. in that year totaled some $24 billion. Today that figure has dropped some 21 %. The after tax rate on return for mining companies has fallen from 6'/% in 1980 to minus 3% in 1983. But that's really not where our problems began. They began 20 years ago when a profound change began taking place in the U.S. economy. Our economy had been growing at about 2'/-3% annually without exception except for the great depression. Our inflation rate was about I'/%, interest rates were running about 6%, and the federal budget was $77 billion, really great figures compared to today. From 1960 to 1980 the federal budget increased almost 1.000% and taxed paid by individual families increased by 700% during that same period. Despite the huge increases in taxes, the federal deficit kept getting larger and larger year after year and within this 20 year period the national debt climbed to a trillion dollars. Economic progress of this type can't continue indefinitely without some serious consequences. The result of that economy, well, you know what happened and there is a direct relationship of that

Jan 1, 1983

By Jack F. McQuat, Ross D. Lawrence

"Most geologists and mining engineers, in the course of their professional careers, frequently become involved with the appraisal of metalliferous mineral deposits and develop a familiarity with and standard approach to the evaluation of these deposits. When the same individuals approach the industrial mineral field, however, their usual approach pattern can be rudely disturbed.This paper highlights the difference in appraisal approach and outlines the factors common to both but which have entirely different emphasis. These comprise geological appraisal, analytical requirements, the importance of transportation, marketing requirements and standards, including appropriate allowances for product development, and marketing penetration.Out of these ""different"" considerations, however, a pat-tern or standard approach emerges which is as common to the industrial mineral field as that used either consciously or subconsciously in the metallic field.The paper reviews the different factors and points of emphasis and offers an outline of the common pattern of appraisal for industrial minerals."

Jan 1, 1971