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By Bates H. Murphy

There is one quick way to substantially reduce the operating cost of a great many pining operations. It is to cut the demand charge on the use of electricity and gas. Demand charge is the utility company's charge for the maximum rate of energy usage which is in addition to the charge for the total amount of energy used. Energy demand is reduced by prohibiting simultaneous operation of devices, especially those that consume large amounts of energy, or by deferring the use of such equipment as air conditioners from one demand period to a subsequent period. To achieve that end, a control system can continuously measure the demand and turn off selected loads in accordance with established rules. Because of the complexity of most industrial plants, a computer is the best means of storing, measuring, calculating, and controlling the many variables associated with the many devices involved. A computer system for that use has been developed by the Westinghouse Computer and Instrumentation Division in Orlando, Florida. For most applications, this demand control system can be installed and operated by industrial plant engineering personnel with no special knowledge of computer technology. It can be used with both electrical and gas service. For clarity, let us examine electrical demand first.

Jan 1, 1974

By Sergio Flores, Nate Long, William Hodder, Phil Rhodes, Tim McQueary

The Surface Water Supply Project Segment B3 is a 4 miles section of tunnel that will run East- West in Houston TX, from Hopper St to I-45. The tunnel will be mined by using a 128" Dia refurbished 1987 Lovat Tunnel Boring Machine capable of operating in Open or EPB mode. The tunnel will be temporarily supported with ribs and lagging and a 96" Dia pipe will be grouted into place. All four miles of this project are within Petroleum Pipeline Easements. The project includes seven shafts, 2000' of tunnel in potentially petroleum contaminated ground, crossing the Hardy Toll d, I-45, the nion Pacic ailroad ight of Way and multiple oil and gas pipeline crossings. This paper summarizes the planning and drive performed to date.

Jun 23, 2024

By L. Adler

Existing classifications of mining and construction equipment have had major deficiencies. They often lack organization, balance, and have remained obscure. Particularly when proceeding to great.er resolution these deficiencies have proven crippling. By adopting "Classes", "Groups" f "Types" and "Kinds" at successive degrees of refinement, a "Taxonomy" is developed based on clear visual differentiation or on a "Morphology??. This symbiotic application, adopted from the Biological Sciences, yields clear, simple and unambiguous results. Supporting this effort are guidelines for easily and credibly sketching equipment which are also distinctive. Numerous illustrative examples are provided. Communications are improved and the engineer obtains a confident feel for the equipment at hand.

Jan 1, 1989

You have been involved with research activities in froth flotation and size reduction. What do you think the future holds for these technologies? Froth flotation and size reduction are essential processing steps common to almost all current mineral-processing operations. The most significant recent advances in both of these technologies have been in the increased size of equipment and in some alternative machine designs, such as the column cells and the high-pressure roller mills. I believe that the next major area of improvement in size reduction will be at least partially driven by an improved awareness of controlling the conditions that influence the efficiency of particle breakage. This would include factors such as water-chemistry influences, the influence of fines from classification, chemical grinding additives and better rheology control. In froth flotation, significant changes are currently taking place in the plant use of frothers. Also, there will be an increasing number of new collector chemistries for certain types of flotation, such as with oxide minerals, oxidized mineral recovery in sulfide systems and improved selectivity with certain sulfide mineral systems. You have been active in implementing new engineering technology in industry. What do you think will be the technological future of mineral processing? Being involved in the invention and industrial implementation of new technology has been one of the most positive experiences of my career. I also have had the unique experience of working in the chemical and petroleum industries as well as in mineral processing. In my opinion, the future of mineral processing will be an exciting, wonderful work area in which to be involved. The development of new technology in minerals processing offers a special challenge compared, for example, to that of chemistry or chemical engineering. In successful industrial innovation involving minerals, having a sound theory is not enough. Instead, what is required is a valid blend of a good idea, meaningful laboratory characterization and, most key, the experience necessary to adjust the plant in such a way to incorporate the idea. The complexity of engineering systems that contain solids, liquids and gases, as well as highly variable natural mineral properties, means that nothing new comes easily. In some cases, it has been difficult to explain how processes practiced in industry for decades actually work, in terms of physical and chemical fundamentals. On the other hand, when a new idea is successfully implemented, the economic and professional returns can be very rewarding. I know of no more challenging field of engineering than minerals processing. What is your view of the future of the minerals industry in general? The need for minerals, metals and coal will be with us for decades to come. In many aspects, the minerals industry became global much earlier than some of the other industrial sectors that are currently experiencing globalization. I believe that fair international competition is beneficial to the users of minerals, metals and coals and to those involved in producing such materials. The key word here for a global economy to work is "fair." So the various playing fields involved such as finance, profit return, regulation and labor should be relatively level for all the players involved. Competition is an amazing driving force for innovation. This has been true in the minerals industry during the last few decades. The mining industry is producing more at less cost per unit than ever before in our history. I anticipate that this trend will continue as long as the global political situation remains relatively stable.

Jan 1, 1997

By Nick A. Hasenack

A full survey of the laboratory and blast-furnace tests on 2 types of acid pellets is given. From the laboratory tests, carried out in an atmosphere containing hydrogen, it appears that type B, produced out of 100% magnetitic ores, has a far better low temperature disintegration index and a lower reducibility index than type A, produced from a hematite/magnetite mixture. The swelling index, chemical composition and mechanical properties of both types of pellets do not differ significantly. From the blast-furnace test, carried out with a burden consisting of 45% of pellets and 45% of sinter with basicsty ratio about 2.2, and at constant driving rate, it follows that there is no significant relationship between the disintegration value of the pellets and the blast-furnace permeability. If also is concluded that the lower reducibility of the type B pellets leads to a significantly higher coke consumption.

Jan 1, 1975

By George H. Willis

In the second half of the nineteenth century, bimetallism progressively replaced by gold standard. After World War I and 1931-33 depression, gold mainly reserved for official international transactions and internal use restricted. Changes since 1971 have shrunk official international use of gold. International payments deficits and surpluses now financed by private and official credit, rarely by gold. Historical review covers evolution of: (1) internal and external private use, (2) internal official use, (3) external official use, (4) role in IMF and (5) use as unit of account.

Jan 1, 1978

By D. Hodouin

Abstract. Dynamic experiments were performed in a continuous open-circuit 40x40 cm ball mill using a pseudo-random binary sequence of the feed rate and measuring the variations of the discharge particle-size distribution. The impulse response is calculated by a cross-correlation technique. Then a model involving a discrete transfer function and a time-series stochastic equation is calibrated using maximum likelihood methods. Based on this empirical model. a minimum variance controller with constrained input is designed and its performances are compared. by simulation, to the performances of a conventional PID regulator.

Jan 1, 1987

By Donald W. Breck

Zeolites were first recognized as a new group of minerals by Cronstedt with the discovery of stilbite in 1756. The word zeolite was coined from the two Greek words meaning "to boil" and "a stone" because of the loss of water when heated in the mineralogist's blow pipe. (1) In 1845 it was discovered that certain soils have the power of retaining ammonium Salts. (2) These were the first ion exchange experiments. Later it was discovered that it was the hydrated silicates in the soil that produced this phenomenon and several years later a paper was published dealing with the action of dilute salt solutions on silicates which showed that this base exchange principal, which we now call cation exchange, is reversible. The quantitative cation exchange behavior of zeolite minerals, such as chabazite, was studied. As a result any aluminosilicate which exhibited the property of ion exchange was referred to as a "zeolite;" even today the term has been applied to clay minerals as well as synthetic organic ion exchange resins.

Jan 1, 1973

By C. I. Basilio

Pearson's hard and soft acid and base (HSAB) principle may be applied to flotation systems. The HSAB principle states that hard acids prefer to bond with hard bases and soft acids prefer to bond with soft bases. By determining the Drago E and C parameters for the different components of a flotation system, the HSAB principle could be used to explain the selectivity of some collectors such as thionocarbamates against some minerals. Determination of these parameters is done by utilizing Drago's theory and flow micro-calorimetry.

Jan 1, 1991

By Richard D. Lang

Introduction Argyle is located in the Kimberley region in northwest Australia (Fig. 1). It is a significant diamond discovery by world standards and is the first major diamond find in Australia. The deposit consists of a pipe and associated alluvial deposits. Before the 1970s, diamonds were known to exist only sporadically in Australia. They have been found occasionally in association with gold deposits in Western Australia. There is a small deposit near Copeton in New South Wales. Some alluvial occurrences have also been found in Victoria, South Australia, and New South Wales. The first indicator minerals in the Kimberley region of Western Australia were discovered in January 1973. Production from the alluvial deposits at Argyle began in 1983. A $430-million construction program to develop a mine and treatment plant capable of producing 25 million carats per year was completed in December (1 carat = 0.2 grams). Ownership and management Participants in the project are known as the Argyle Diamond Mines Joint Venture. The group consists of CRA Ltd., 56.8%; Ashton Mining Ltd., 38.2%; and the Western Australian Diamond Trust (formerly Northern Mining Corp.), 5%. The project is managed by Argyle Diamond Mines Pty. Ltd., a wholly-owned subsidiary of CRA. Marketing is undertaken separately by the Western Australian Diamond Trust and by Argyle Diamond Sales Ltd. (for CRA and Ashton Mining groups). History Ownership of the Exploration Joint Venture has changed over the last 12 years as various parties changed their shareholdings. The original Kalumburu Joint Venture was formed in 1972 with five participants, each holding a 20% interest. By 1983, a number of ownership changes had occurred. The end result is that two original participants have sold out. CRA now holds a 56.8% share and the Ashton Mining Group holds 38.2%. CRA also assumed project management in January 1977. Table 1 demonstrates the long lead times involved in developing a project.

Jan 1, 1986

By David B. Brooks, Roger L. Williams

Control of the environment is as old as mining. Engineers have always had to consider how best to deal with the surface, and the character of the surface environment always affects mining method in some way. However, if the relationship of the mine to the environment is old, today's approach is new. For one thing, land, air and water formerly could be viewed simply as obstacles to be overcome or resources to be utilized to win ore at the lowest possible cost. Now we have come to realize that these nonmineral components of the environment also are highly valuable. For another thing, environ- mental protection has become a public policy issue. Again, a special public interest in land and land use is old. From the firs(, the crown claimed extra rights in valuable minerals, and to this day a multitude of laws and regulations control-and tax-land use in every country. What is new is the detailed public attention bring given to waste management practices, whether these wastes be in the form of solids, liquids or gases, and regardless of where in the environment they appear. (It is convenient to lump all mining environmental problems, including hank fires and subsidence, together under the term "waste management," for in effect that is what they are.) As a result of these changes, the mining engineer must consider that lie is dealing with two productive resources the minerals and the remainder of the environment-and he must expect that lie will be judged not only on his efficiency in recovering the one but also on his effectiveness in protecting the other. Further, in seeking to protect the environment, the modern mining-environmental engineer has a dual role. First, there is the obvious task of finding better ways for industry to cope with waste-management problems in actual operations. Second, there is the less obvious but equally important task of helping formulate appropriate public policy objectives for the environment. Throughout; the section it is assumed that mining is an acceptable land use for the tracts under consideration. The question of whether mining will be permitted at all on these tracts is a further public-policy issue, ultimately to be resolved politically and thus, since it is beyond the scope of engineering, is not a subject that can be usefully discussed in a mining handbook. Finally, none of the statements in the section are predicated on the assumption that required waste-management measures will be privately profitable in the conventional sense. Indeed, the reverse is more likely to be the case-at least if accounts are kept so as to include all appreciable costs and a normal rate of return on investment in waste-disposal and reclamation equipment.',',' However, it is clear that improved waste management will be required of mining firms and that, to a considerable although undetermined degree, this expenditure is in the best long-run interest of both public and industry. The several studies that have attempted to quantify the impact of mining on the environment are admittedly rough but still provide enough information to indicate that there is a big job to be done. For example, something approaching 7,000 mi of stream in Appalachia alone are continuously or significantly affected

Jan 1, 1973

Laboratory testing by the Federal Bureau of Mines has shown that the removal of insoluble slimes using selective flocculation and flotation is a viable method for treating low-grade potash ores which have a high content of water-insoluble impurities. Results indicated that up to 85 percent of the insoluble slimes could be removed from sylvinite ore containing 5 percent water insolubles and 13 percent K20 using nonionic or cationic polyacrylamide flocculants and cationic, anionic, and/or nonionic collectors. Subsequent potash flotation recovered up to 88 percent of the potash in rougher concentrates containing 47 to 57 percent K20. Sizing and cleaner flotation of the rougher concentrates upgraded the products to 60 percent K20. Filtration of the insoluble slimes flotation concentrates recovered 87 to 0 percent of the brine. Flotation concentrate filtration rates were 7 times faster than the filtration rates of mechanically deslimed products.

Jan 1, 1977

By Yingbao Yang, Jinyue Liu, Yonggang Wei, Bo Li

Due to the depletion of copper ore with high-grade and low impurity contents, the raw materials for copper smelting exhibit low copper contents and high impurities. High-impurity elements lead to the poor performance of the final copper product; thus, the removal of impurity elements during the oxygen-enriched copper smelting process is crucial. In this study, based on the production of high-grade matte, the occurrence states of impurity elements (such as As, Pb, and Zn) are analyzed in the input and output materials of the oxygen-enriched smelting process, and the phase transformation mechanisms of impurity elements are revealed during the oxygen-enriched smelting process. The effects of temperature, Fe/SiO2 ratio and oxygen concentration on the distribution behaviors of impurity elements in dust, slag and matte and the removal rates of impurity elements in matte are clarified. The results show that the impurity elements mainly exist as As4, As4S4, As2O3, Pb, PbS, PbO, Zn and ZnS in dust, as FeAsO4, As2O3, FeAsS, PbSiO3, Zn2SiO4 and ZnFe2O4 in slag, and as As, FeAsS, PbS, PbO and ZnS in matte. High smelting temperature, low Fe/SiO2 ratio and low oxygen concentration are beneficial for improving the matte grade and the removal rates of impurity elements Pb and Zn in matte. Low smelting temperature, low Fe/SiO2 ratio and high oxygen concentration are beneficial for removing impurity element As in matte.

Aug 8, 2023

By Jurij Karlovšek, Marko Žibert, Scott Keniston

"SUMMARY The importance of information management was recognised in surface construction industry decades ago, and has increasingly being recognised through formal process and laws. Around the world, these laws and codes of practice are currently being drafted and enacted, to reflect the development of software tools and corresponding increasing adoption by industry. This paper deals with specifics of implementing information modelling in tunnelling business utilising BIM (Building Information Modelling) technology developed for buildings as well as similar technology developed for mining industry. Although BIM is recognized initially as a 3D digital representation of physical and functional characteristics of a facility, the real benefits come when complex capability through construction sequencing and even detailed programming (4D) and cost capabilities (5D) are included. INFORMATION MODELLING The Architecture, Engineering and Construction (AEC) industry requires the production of design and construction information, which involves the input from several teams. The tasks allocated to each team need to be carried out in a particular order and coordinated in order to benefit all those involved and the project itself; this is known as “collaborative working”. To ensure the quality, and guarantee that information can be used without change or interpretation, working processes and standards needs to be agreed upon or else it will hinder collaboration and have a negative impact on project delivery. Case studies show that the additional capital delivery costs due to uncoordinated, inaccurate and ambiguous information amounts to 20-25%. The solution to overcome these problems and improve collaborative working in a project is the adoption of BIM. It is a modern approach to the design, documentation, delivery, and life cycle management through the use of project information databases coupled with object-based parametric modelling. BIM requires traditional practices shifting from simple drafting to using 3D native models for building design environment. Additionally, it requires that models are equipped with information that has been traditionally decoupled in a text or other kinds of documents. The goal is not in creating a 3D graphic representation of design intent; rather, it is a comprehensive information management tool based on the simulation of design and construction build around a central repository."

Jan 1, 2016

By R. B. Tippin

The material balance computer program (MAT-BAL) developed at the Minerals Resource Research Center of the University of Minnesota, has been used in conjunction with routine process profile samples taken in the potash compaction plant at Great Salt Lake Minerals and Chemicals Corporation, Ogden, Utah. In this manner, a uniform data base is being established for the process, and selected key indicators are used for decisions in plant operation and maintenance. With present emphasis on improving product quality and increasing production rates, the standard data base system provides a means of measuring results from test programs to optimize the circuit. The development and application of this process control method is discussed. The compaction plant computer-assisted data base has been in existence for only two years, but it has made significant contributions to the knowledge of the process and continues to assist in monitoring the plant performance. It is anticipated that the material balance program will be adapted to the GSL flotation plant in 1979, and to other circuits in the potassium sulfate chemical plant.

Jan 1, 1979

By V. Montaruli, A. Nieto, M. Cardu

Nickel is a metal whose workability and mechanical strength at high temperatures and in corrosive environments makes it an indispensable alloying element for the realization of stainless steel, specialty steel, super-alloys, rechargeable batteries and electroplating. Because its main fields of application are key to the development of industry and, thus, to society, nickel has recently been recognized as a potentially critical mineral, despite its abundant reserves. The purpose of this paper is the creation of possible case scenarios determined by factors and events that, in the medium to long term, could change the current structure of the nickel market on the demand and/or the supply side. Four scenarios have been determined by considering a demand variation due to the occurrence of a natural disaster and an aerospace plan implementation and taking into account the resource nationalism and the skills shortage as supply varying factors. Through the creation of a georeferenced global nickel database, the paper proposes supply strategies related to the four scenarios for each top nickel consumer: China, India, European Union, United States and Japan.

Jan 1, 2013

By A. D. Davis

Environmental impacts from acidic mine drainage are growing national concerns that are particularly acute in the headwaters of the Rocky Mountain region. In the Black Hills of South Dakota, approximately one thousand mines are inactive or abandoned, most of them in the headwaters of major drainages. This paper examines the Bear Butte Creek basin, a heavily mineralized watershed with significant historical mining impacts and a surface gold mine permitted in 1997. The watershed loses its surface discharge to swallow holes in the karstic Madison Limestone. The integrity of the aquatic ecosystem was monitored with a suite of site-specific bio-indicators. Stream surveys covered the entire reach of Bear Butte Creek from near its headwaters to the swallow holes in the Madison aquifer. Data from the stream surveys, water-quality sampling, and bio-indicator surveys clearly showed that water-quality impacts are limited mainly to Strawberry Creek and to the area of Bear Butte Creek near and downstream of the town of Galena.

Jan 1, 1999

By Graham A. Brown

Activities in offshore mineral exploration In Australia are increasing almost daily, at such a rate that this report will rapidly become out of date. At the time of writing, February 1967, there were no commercial discoveries of offshore minerals reported in Australia, although there has been definite encouragement in many fields. While this initial encouragement has not revealed any commercial mineral deposits offshore hopes are running high in Australia for success in 1967. Why should mineral deposits be expected offshore in Australia in the first place? The reasons are many. The minerals to be discovered also are many. The reasons are based on the history of alluvial and beach mining activities in Australia's past and at the present time, and on the physical environment of the vast Continental Shelf which surrounds the continent. A brief examination of the two primary features which are necessary before offshore mineral exploration can be contemplated should be, undertaken. Two favourable environments are necessary; firstly a Continental- Shelf to form a physical environment for the accumulation of the mineral deposits, and secondly a favourable political-legal environment to give the exploration companies adequate protection during exploration, and suitable long term arrangements for the exploitation of the deposits after discoveries have been made. Australia is well endowed with both of these.

Jan 1, 1967

By Thomas P. Meloy

Floating "fines" differs from floating "sands" because the fines have a much larger surface area compared to their mass. The forces that arise from this large specific surface the key to understanding the behavior and treatment of fine particles. Though the nature of these forces is not thoroughly understood, enough work has been done to give a qualitative picture of what is happening in a flotation cell. It is the purpose of this chapter to re-examine some of the more, recent theoretical work and-to indicate its importance.

Jan 1, 1962

By S. Deming

Coal is China's main source of energy. In 1988, 76.1% of commercial energy consumption was supplied by coal. To provide a rational utilization of its coal resources, China has paid considerable attention to coal preparation over the last 10 years. In 1980, there were only 105 washeries treating about 100 million tonnes of coal, but by 1988 there were 151 washeries treating 171 million tonnes per year. This paper describes the development of China's coal preparation industry; its growth, the equipment, and the technology. Statistics and information on the current status of the industry are also be presented.

Jan 1, 1991