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By R. E. J. Putman

The, principle purpose of applying control to any process is to improve -its profitability. Even when considering the impact of a plant on its surrounding ecology this is still, true, since the sanctions felt most immediately from violations of the regulations are the economic penalties or fines which result. 'Economic performance can be improved within a plant in several ways. Steps can be taken to cut the cost or quantity of resources (power, water, steam, reagents) consumed per ton of throughput. Alternatively the operation of the plant can be changed so as to increase product yield per ton of throughput. Or the cost of labor and plant overhead per ton of product can be reduced by raising the total 'throughput, assuming-that the increased amount of product can be sold for the same unit price. In designing a program to improve plant performance, all three routes should be borne in mind. To maximize the return on investment over a longer period, it is also desirable to set up a comprehensive plan of improvement, equipment being specified at each step in the implementation so as to ensure that it fits in with later requirements later implementation being either by means of modular additions or by having the necessary interfaces built into the original equipment. It is much cheaper in the long run to buy features which have been factory-installed, than to have to make provision for their later addition in the field. This paper examines some ways of improving plant performance by the application of various process control techniques using both analog and digital con¬trol equipment. A general philosophy of application is suggested and specific examples described.

Jan 1, 1972

By Greg Barnes

Agenda ? The Mining Stock Life Cycle ? Current Environment ? Valuation ? Golds ? Valuation ? Base Metals ? Case Study ? Quebrada Blanca Hypogene Commodity Investment Cycle ? Macro-Economic Indicators ? LME Inventories ? watch the trend; rising inventories ? bad for prices, declining inventories good for prices ? OECD Leading Indicators ? PMIs ? Purchasing Manager Indices ? Industrial Production ? more important for metals consumption than GDP ? Housing Starts ? US, Europe ? Auto Sales ? All things China ? metal imports/exports; SHFE inventories; SRB stockpiling ? Seasonality ? it does play a role ? What is Chris Dutton (TDSI Quantitative Analyst) saying?

May 1, 2010

Studies of coal reserves have shown that the total augerable reserve base for the United States is estimated to be five billion tons under the current state of mining technology; the potential reserve base at 850-ft penetration is estimated at 20 billion tons. It is with the idea of improving coal recovery, a basic objective of Project Independence, that new concepts, such as modifications and improvements in current machines and development of ways to recover pillars left by current augering, are required. Unless recovery is improved, these potential reserves amount to lost coal.

Jan 1, 1975

By A. E. Soregaroli, H. D. Meade

"The Keystone porphyry molybdenum deposit, located in southcentral British Columbia, is hosted by intrusive rocks of the Cretaceous Mount Lytton batholith and the early Tertiary Keystone quartz diorite stock. The molybdenite mineralization is associated with rhyolite porphyry dikes flanking a large 1300 m by 2100 m breccia complex. Recognition of the potential for the buried molybdenum porphyry system was based on quartz-molybdenite vein fragments within the hydrothermal breccias.The full extent of the molybdenum mineralization is not known. The few deep drill holes along one comer of the breccia complex defines strong metal zoning of molybdenum and associated elements of F, Mn, Zn, Pb, Au, Ag, Fe and W about the molybdenum stockwork mineralization that may be useful for guiding additional exploration. The best mineralization occurred near the base of the deepest drill hole with 0.114% Mo in rhyolite porphyry near the edge of the breccia pipe at a depth of 1350 m.The exploration history of the deposit has been complex, focussing on both porphyry-style mineralization and precious metal veins and stockworks on the periphery of the porphyry system. Exploration to date has defined an attractive porphyry molybdenum system with uneconomic grades at great depth; however, there remains significant potential to define economic mineralization elsewhere in the Keystone porphyry system and adjoining occu""ences."

Jan 1, 1995

Satisfactory means of managing growth in boom towns is a concern in mineral, energy and other large industrial developments. This session will include examinations of socioeconomic impacts, major issues such as social disruption, case studies, methods of managing growth, and concerns involving Indian lands. Innovative methods will be offered to assist the public, government, and industry in finding solutions to managing growth in rapidly growing communities.

Jan 1, 1979

By P. A. Cox

The purpose of the initial research performed under this contract was to determine the margins of safety in explosion-proof (XP) enclosures, which were designed and certified according to the current schedule (Schedule 2G). Results from this work provide baseline data on the current schedule, from which a new schedule can be formulated to give equal or greater levels of safety. Results and discoveries in the initial work led to an expansion of the contract to cover, additionally, weld quality in enclosure fabrication, reliability of enclosures with windows and lenses, and performance tests for enclosure qualification. Finite element calculations and hydrostatic tests revealed wide variations in the margins of safety in the enclosures studied; however, only one enclosure had a safety factor which was less than one. Results from a weld quality survey led to the recommendation of AWS Welding Standard D14.4 for the fabrication of XP enclosures. Based on other work, accelerated aging tests were recommended for qualifying plastics and adhesives that are used in some enclosures, and a Structural Performance Test was developed to test enclosure strength for a minimum static pressure of 150 psig.

Jan 1, 1982

By William Hissem

The topics in the title line of this article are desirable and applicable to entire industries that exist outside the realm of the ISEE’s readership. But the issues I will discuss herein are specific to those who drill, blast, and excavate rock as part of their business. Civil and site construction projects, mines, and quarries specifically comprise the group who will benefit from this discussion.

Jan 1, 2014

By Mackenzie Burnett

An inducer-type pump, capable of injecting dry coal into a hydraulic transport pipeline has been developed and installed in a specially designed and fabricated slurry injector vehicle. The full scale prototype injector system can deliver up to 11 ton/min of coal into an 8-in pipeline t pressures up to 95 lb/in2. The Helical Inducer Injector operates on centrifugal principles with flow passing axially through helical pitched conical rotor. Water is delivered to the pump through an annular slot at the atmospheric pressure coal inlet. The spinning rotor maintains an air-core vortex of water which pressurizes the discharge housing. A screw feeds coal through the open inlet into this vortex. The inner radius of the vortex contracts as pressure is increased, giving a limiting maximum pressure which is proportional to the square of the rotor speed. Below this limit, flow rate, discharge pressure, und rotor speed re independent variables. The self-powered, 4 -in high slurry injector vehicle follows and receives ROM coal from a continuous miner, reduces the top size to 3-in, and delivers the sized coal to the injector feed screw for slurry formation and pumps it through a mobile hose attached to the vehicle's outby end.

Jan 1, 1983

By D. M. Carris

Since the Buffalo Creek incident in February, 1972, Federal and state environmental agencies have had the pressure on the coal industry in the Appalachian area to close the coal processing plant water circuits. In an attempt to comply with this requirement, Eastern .Associated Coal Corp. decided to install a vacuum disc filter system at its Kopperston plant to eliminate the tailings pond and reduce the amount of plant make-up water. It was recognized at the time that the plant static thickener tailings would be a very difficult slurry to dewater because of its unusually high clay content. The following is a case history of the Kopperston installation and the refinements Eastern has made in its vacuum disc filter operation to increase efficiency.

Jan 1, 1979

By David Bendersky

This report covers the activities of a feasibility study of fiber optics technology fur use in mines. The objective of the study was to evaluate, both technically and cost-wise, the possible use of fiber optic technology for underground mine communication and monitoring systems. The first phase of the study was devoted to the collection of information on the present underground mine communication systems and monitoring techniques, and the status of applicable fiber optic technology. In the second ph se of the study, a communication and monitoring system for a hypothetical underground coal mine was designed and the costs estimated. The significant findings and conclusions are presented.

Jan 1, 1982

By A. E. Kehew

Earth resistivity surveys using the Wenner electrode configuration were made in unmined areas and reclaimed spoils at three surface lignite mines in western North Dakota. The study sites were the Center, Indian Head, and Falkirk Mines. Automatic interpretation of the curves was accomplished with the method of Zohdy and Bisdorf (1975). Overburden materials become more homogeneous with respect to resistivity during the mining and reclamation process. The spoils curves show localized hetero-geneities probably related to discontinuous moisture content variations in the spoils. Consistent resistivity differences in spoils occur between mines with over-burdens of different mineralogic compositions. Groundwater chemical composition in terms of total-dissolved-solids (TDS) is inversely correlated (r=-0.61) with apparent resistivity at the 80-foot spacing from a survey centered at a piezometer screened near the base of the spoils. Better inverse correlation is probably pre-vented by high variability in TDS within the spoils groundwater. A useful predictive relationship may be the plot of mean apparent resistivity at the 80-foot spacing for ar. entire mine against mean TDS for all wells in spoils at that mine. Data from more mines are needed to test the hypothesis.

Jan 1, 1982

By Rob van Opbergen, Edo Engel

The highly dynamic economic climate of recent years has tightened the operating envelope for steel producers world-wide. Steel producers continue to experience immense pressure to respond quickly to changing circumstances and the focus has shifted towards efficiency improvement and maximizing flexibility in operations. The ability to safely stop, restart and ramp-up production facilities has become essential. Establishing this level of flexibility, without sacrificing efficiency, requires sound process control, fit-for-purpose process management practices and solid know-how and experience regarding special situations in blast furnace ironmaking operations. The same business environment that demands this increased flexibility has made it increasingly difficult for steel producers to sustain sufficient knowledge about these situations. While many experienced, senior operational staff have retired, a new generation of ironmaking specialists has acquired its hands-on experience over more recent decades, during which these process situations have been much less frequent than before. Over the past 10-15 years, the requirement in the industry for external operational support during e.g. blast furnace blow–downs, salamander tapping and restarts after planned and especially unplanned stops, has become increasingly frequent. This article presents a number of these cases from a process management perspective as well as with regard to project organization and optimized cooperation between internal and external teams of experts.

Oct 1, 2019

By Oliver Bowles

ASBESTOS is a name applied to a group of naturally fibrous minerals. As indicated in a later section devoted to a detailed discussion of the early history of asbestos, the tern may be defined as a. fibrous form of serpentine or amphibole. It does not include fibrous forms of other minerals, such as wollastonite, nemalite (fibrous brucite), or the fibrous forms of calcite or gypsum. A material that has the characteristics of silk or cotton and at the same time will not burn is unique. Because it combines these qualities with other advantageous properties, asbestos has specialized uses for which no substitutes are yet available. Asbestos furnishes a major raw material for a great variety of essential products and their manufacture constitutes a vast industry. The United States leads all countries in the manufacture of asbestos products. The value of such commodities manufactured in 1952 exceeded $332 million. They are not only of vast importance to budding construction and industry but axe absolutely, essential to certain important fields of use, for example, steam packings and friction materials, such as brake-band linings on automobiles.

Jan 1, 1955

By G J. A Dewar

The Australian Corporations Law generally requires Independent Expert Reports to be presented in support of capital raising or in defence of mergers and takeovers. The introduction of the VALMIN Code in 1995 (and its recent revision issued as the VALMIN Code, 1998) made Assessment and Valuation Reports in these circumstances much more comprehensible than before because of its key requirements for transparency and materiality. By forcing the Independent Valuer to provide an explanation of the reasoning behind the estimation of a particular resource asset, VALMIN allows the reader to clearly see any error or illogicality in the valuation methodology used and to seriously question or even reject the resulting value. Even though many elements of resource asset valuation practice are undeniably subjective, there must be some basis of objective rationality to it. Independent resource asset Valuers are the essential link between mineral explorers/miners on the one hand and brokers/analysts/fund managers/investors on the other. The minerals and financial industries both expect them to not use inappropriate or invalid valuation methods and illogical steps within these methods. This paper examines some of the less sensible ways in which some of the main techniques that Valuers commonly use to assess the fair market value of mineral properties have been applied in recent instances. The authors hope to discourage the adoption or perpetration of the æWhat-number-did-you-have-in-mind?' approach. It is MINVALÆs view that as many methods as possible should be used in any resource asset valuation. If any of the resulting estimates are in approximate agreement (particularly if they were derived using the less subjective of the available methods), ie if they cluster, they are probably more persuasive as being the Preferred Value of the asset than outlier values within the Valuation Range.

Jan 1, 1999

By The Staff

THE object of the work was to increase the capacity of the plant and, if possible, to reduce costs of the actual unit grinding while doing so. The accompanying assays of an infra-sizer analysis of the cyanide tail (Table l) illustrate the problem in hand. The cyanide tail is a combination of two products, gangue and FeS2. The assay alters by virtue of a change in gold value due to grinding and the relative quantity of FeS2 in the sizes, which itself varies with the grind. The disposal tail is the residue after the cyanide tail is scavenged by flotation, most of the pyrite being removed for roasting. It presents a somewhat different problem, since grinding gangue is all gain, but -10 micron FeS2 does not float nearly as well as + 10 product. This results in compromise in the final size to be aimed at. Extra grinding has hardly any appreciable effect on the gold extraction from the FeS2. (See Milling Investigations Into the Ore as Occurring at the Lake Shore Mine; Trans. C.l.M.M., Vol. XXXIX, 1936).

Jan 1, 1940

By G. F. Kuncir

The analysis described herein evaluates the Bureau of Mines Program for Advancing Mining Technology - Oil Shale in terms of the economic benefits which may be derived for the Nation as a result of its successful research and development efforts. On the basis of postulated oil shale production scenarios, benefit-cost ratio indicators are computed for the program elements as they apply to surface, underground, and modified in situ oil shale mining systems. Eight value indicators are used to measure the Program's beneficial impact on the future oil shale industry in relation to planned research and development costs. These are: capital cost savings, operating cost savings, labor savings environmental quality maintenance cost reduction, reduction in production costs, byproduct production benefits, total production benefits, and additions to recoverable reserves. Program costs are aggregated from 1974 through 1987 and major benefits are accrued from 1982 through 2040. Both cost and benefit streams are discounted to mid-1975 present value.

Jan 1, 1977

By Dodd SF

Valuation of mining companies and their underlying assets prepared by brokers' analysts are, by necessity, approximations. The reliability of the valuations is entirely proportional to the quality of available data, the reliability of forecasts and the nature of underlying commodity price assumptions. The latter is perhaps the greatest single cause of gross variations in company and asset earnings estimates and- valuations. Assumptions are often necessary regarding commodity price achievement based on commodity hedge positions. Public disclosure from listed companies provides a sound base from which to project earnings, cashflows and balance sheets. The uncommon disclosure of projected production and cost schedules often reduces the reliability of future estimates. The application of reserve and resource estimates is contentious with practitioners applying differing weightings to importance of resources in estimating mine lives (and therefore cashflow streams). Valuation methods applied in equity markets usually focus on relative value and the identification of pricing anomalies. The commonest ""rules of thumb"" applied in the valuation of mining companies (and therefore their underlying assets) is with the use of year specific price/earnings (P/E) and price/cashflow (P/CF) ratios, with low multiples suggesting undervalued assets, high multiples overvalued situations (but these rules can often be clouded by market expectations of underlying commodity price movements). Another simply applied valuation tool is to examine the examine the value placed on reserves and resources by the market. Inexpensive gold in the ground (expressed as $ of market capitalisation per ounce of reserves or resources) might indicate a buying opportunity, but the market does discount the value of gold in the ground prior to mine development and where development risk is perceived.

Jan 1, 1994

By N. Yamazaki

The supply of clean copper ores, which have high copper concentration and low impurities like arsenic, has declined year by year. Therefore, both mine and smelter sides have to consider how to remove impurities like arsenic. We focus herein on arsenic as an impurity because it is an extremely important issue from the environmental point of view. Approximately 150,000 t of arsenic is input into the copper industry every year. A small part of it is mainly treated in the smelting side. For instance, Ministro Hales Limited, which is a mining corporation in Chile, has performed the calcination process to remove arsenic from ore with high-arsenic content. In the process, flue gas is washed by water, and the final residue is treated by a hydrometallurgical process. Many processes for arsenic removal in various stages have been proposed, and several bottlenecks exist to achieve it. One of the difficulties encountered is getting an assessment of the process, which depends on the countries and/or areas of operation. The standardization of the assessment procedure will be desired in the near future to keep the same environment standards all over the world, and now is the time to start making discussions on this matter. This will be the first step in making an international assessment procedure for arsenic treatment in the copper industry. INTRODUCTION Using the term “sustainable development” without any scientific basis can give people a false sense of security. Engineers and scientists must analyze the total mass flow of energy and materials and estimate local drain on the environment as well as the global impact of a particular industrial activity to ensure sustainability on this planet. The operations of the mining and smelting industries have a strong effect on the environment even if they provide useful materials for human beings. The copper mining and smelting industries have brought about serious environmental problems in the past. For example, the Ashio mine pollution caused big damage to the agricultural sector near the Ashio area in Japan in the late 19th century. One of the most serious problems at that time was SO2 emission because copper ore is sulfide, and the smelting process basically results to sulfur oxidation. The resource balance from a copper smelter in a year, assuming a total production of 16 million tons, can be summarized as follows: discarded minerals, 30 billion tons; sulfur, 16 million tons; iron oxide, 8 million tons; additional smaller amounts of other metals, electricity, and fuel.

Jan 1, 2019

By G. E. Murray

Introduction The development of the method for recovering zinc from lead blast-furnace slags at Trail is interesting and important in the history of both lead and zinc metallurgy. Many efforts have been made in the past, particularly in Germany, to make economic recovery of zinc from slag. The Pape process on Oker slags was successful and is being worked at the present time. More recently the Waelz process has come to the fore. One effort at Cockle Creek, Australia is of special interest in view of subsequent developments. This was re-ported in detail by Guy Courtney in 1920(1). It deserves mention as it shows how, as in many other instances in the metallurgy of lead and zinc, important pioneering work has been done in Australia. These experiments, started over 25 years ago, comprised reduction with coke, powdered coal, and eletrothermically in carbon-lined furnaces. The so-called slag eye furnace, which volatilised the metals from a blast furnace running with a hot top, was also investigated.

Jan 1, 1933

By J C. Volkwein, A D. A Hansen, E Sarver, C Barrett

Ensuring that diesel particulate matter (DPM) levels in underground metal and non-metal mines are maintained below statutory limits is an essential requirement of mine ventilation systems. However, despite the cost of providing ventilation, air ventilation rates are usually based upon models, assumptions, or measurements integrated over long durations rather than actual need. Real-time measurement of DPM, interpreted in terms of mine activity schedules, can offer better ventilation management to keep DPM within regulated levels while controlling costs. This work presents data from three demonstration sites with in-mine applications of an environmental particulate sensor that measured black carbon (BC) as a surrogate for DPM.Aethalometers are a class of environmental monitors that measure the light absorbance of aerosol particles at several optical wavelengths. A model AE33 Aethalometer was operated in three separate mines for periods of two weeks, three months, and seven-plus months, and the data was reported in real time as a concentration of BC. Concentration of aromatic organic compounds, which can indicate other forms of combustion, was also reported. The data was used to:- measure the relative efficiency of a new scale-model DPM air scrubber- determine if ventilation could be reduced in a shotcrete loading facility without compromising air quality- evaluate diurnal and weekly DPM levels in a large-entry stone mine. Instrument data were displayed locally and stored for later downloading in all cases. In one mine, the instrument was connected to a local controller, and in another it was connected to the mine’s underground network so that DPM data was presented in real time to a display in the mine ventilation engineering office on the surface.The results showed that the air scrubber removes from 82 per cent to 95 per cent of the DPM; that DPM produced during shotcrete loading is only a minor part of overall DPM levels; and that wide variations in DPM levels exist in the limestone operation. The DPM monitor operated continuously for extended periods in these underground environments. The only maintenance required was the routine replacement of filter tape, typically on a two-week schedule. A sample diluter, which is currently being tested, could extend the intervals between filter changes. The real-time data output of the Aethalometer is appropriate for direct integration into ventilation-on-demand control systems.CITATION:Volkwein, J C, Barrett, C, Sarver, E and Hansen, A D A, 2017. Application of an environmental ‘black carbon’ particulate sensor for continuous measurement of DPM in three underground mines, in Proceedings Australian Mine Vent Conference 2017, pp 143–150 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017