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By Jose Luis Lopez Mendez

In May 1992, MEXICANA DE CANANEA, S.A. DE C.V. finalized the life of its Reverberatory Furnace which lasted 16 years. This created the need to prepare the Smelter for the next campaign.

Jan 1, 1994

By R. Barthel, O. Nitzsche, J. Pateiro Fernández, T. Cramer

The Hong Gai coal field in northeast Vietnam has been the main coal mining area of Vietnam for more than 150 years. Anthracite coal is produced from several open pit and underground mines situated close to the UNESCO world natural heritage site Ha Long Bay. The mining-induced environmental impacts such as dust emissions, acid mine drainage, and visual impairments due to waste dumps resulted in severe conflicts of interests regarding future land use and the protection of the world natural heritage site Ha Long Bay. Within the RAME project (Research Association Mining and Environment in Vietnam), Brenk Systemplanung is contributing to an improved environmental and sustainable planning in Vietnam's mining industry and the reduction of environmental impacts on Ha Long Bay by developing suitable and sustainable technology and planning measures (e.g. for dump construction/rehabilitation, predictive modelling, and/or monitoring) for Vietnam's leading coal producer.

Jan 1, 2011

By G Hope, C Young, R. N. Gow

"The presence of enargite (Cu3AsS4) is problematic in gold processing as it is refractory, increasing cyanide and oxygen consumption, and enviromnentally hazardous. Selective leaching and treatment of the arsenic would prove advantageous to conventional gold leaching methods. The reactivity of enargite samples from Montana, US and Quiruvilca, Peru were studied under alkaline conditions, pH range of 8-13, using a cyclic voltammetry corrosion cell setup. Raman spectra of the surface were taken during and after cycling to compare surface species against theoretical predominance diagrams. Under slightly oxidizing conditions, covellite (CuS) peaks were found on the surface in a short matter of time, above - 200m V vs SHE for pH 9-13, suggesting arsenic leaching, but for longer conditioning times, elemental sulfur peaks were also found, which created a passivating surface layer. By operating above pH 12, under reducing conditions, ~-500mV vs SHE, arsenic can be leached as a thioarsenate (AsS4-xOx3-), without sulfur formation.IntroductionEnviromnental limitations on pyrometallurgical processing of arsenic has pushed the desire to process enargite-, Cu3AsS4, bearing concentrates towards a hydrometallurgical solution. Attempts to process can be broken down into two categories - the co-dissolution of arsenic and copper under acidic conditions or the selective leaching of arsenic under basic conditions. The selective leaching of arsenic would preferably leave behind a chalcocite, Cu2S, or covellite, CuS, phase that would be more amenable to conventional processing methods of the copper and gold industries. These methods employ bi- or poly-sulfides to leach arsenic as Assl· [1-4], hypochlorite leaching [5-7], ammoniacal leaching [8] or fine grinding to mechanically activate the enargite surface and increase normally slow reaction kinetics[9]. This study looked into the surface formations of an enargite electrode under alkaline conditions, in a pH range from 8-13, as it cycled from -1000 mV to 1000 mV vs SHE. The understanding of the formations and under what conditions they form will be helpful in further development of any of the aforementioned processes."

Jan 1, 2012

By F. A. Harvey

DURING the last few years, there has been a constant tendency toward increasingly high temperatures in many lines of industry. The necessity for increased production of coke gave a 16-hr. coking period where we used to have 24 or even 30-hr. periods. Mechanical stokers have increased the temperatures in boiler furnaces. The use of a chain-grate stoker with coke-breeze fuel necessitates a low arch in the furnace and temperatures run much higher than firebrick were formerly called upon to stand. These higher temperatures have necessitated more rigid tests and the separation of even high-grade firebrick into separate classes. More severe tests mean higher temperatures and closer control, and this, in turn, means better pyrometer tubes. Platinum couples do not have a very long life when used at temperatures exceeding, say, 1200° C., but the proper selection of a high-grade brick to be used in a-boiler setting will save the cost of several couples; and with freight rates continually increasing it becomes increasingly important to know where brick may be bought, nearest the job, that will prove satisfactory. Couples that will stand continuous use at higher temperatures, of tungsten, molybdenum, or other metal, will doubtless be forthcoming as soon as the need becomes sufficiently urgent. There are on the market several tubes that are entirely satisfactory for temperatures up to 1300° C., if properly protected from heat shock. The Semet-Solvay Co. makes a practice, however, of testing silica and clay firebricks at 1450° C. for 72 hr., and so far we have been unable to find a tube that- is entirely satisfactory for this purpose. A graphic record of the temperature during the entire test is extremely desirable and hence we have been trying out anything that gave promise of success. Several years ago we were using insulating tubes, made purely for electrical work, of vitrified porcelain. These tubes stood up under any temperature we were able to reach and were apparently impervious to gases. When this stock gave out, due to mechanical breakage, we tried other insulation tubes only to have them melt down like glass. Marquardt Masse tubes were tried next under a statement from the distributors

Jan 9, 1919

By David Bartsch

The Ohio Valley Coal Company (Ohio Valley) has operated the Powhatan No. 6 Mine in Belmont County, Ohio since 1972. Ohio University owns a 455-acre research farm over a portion of the Ohio Valley reserve containing 51 acres of old-growth forest known as Dysart Woods. In 1988, when Ohio Valley applied for a new mining area for its first longwall located several miles away from Dysart Woods, Ohio University claimed that mining at that distance would lower the regional water table and kill the old trees. In response, Ohio Valley began to study potential impacts from longwall mining on hydrology, soil moisture, and tree growth. Early studies examined the impacts of longwall mining on hydrology, soil moisture, and tree growth directly over mined areas compared to woodlots that were not undermined. A subsequent study examined tree-ring growth for a five-year period before and after longwall mining for several woodlots, some directly over panels and others at distances of up to 2000 ft away. No significant differences in growth rate associated with longwall mining were observed. New research was begun that compared longwall-mining impacts on groundwater hydrology, available soil moisture, and tree growth in two stands of mature trees located near Dysart Woods in order to confirm the earlier results. Using a test technique known as "Before-and-After-Controlled-Impact-Pairs," data was collected from one woodlot (test) that was undermined and from another (control) that was not undermined. Data collection began several years prior to longwall mining and has continued for several years after mining. The data for the test site shows that although the shallow and deep groundwater levels were affected by longwall mining, the soil moisture, vigor rating, or the growth rate of trees did not decline significantly compared to the control site where there were hydrologic impacts. The study shows that there are no known significant impacts to trees from longwall mining. The results of these studies were used by Ohio Valley to obtain State approval to longwall to within 300 ft of Dysart Woods

Jan 1, 2005

1. Book reviews Phosphate rock, a bibliography of world resources. London, Mining Journal Books Limited, 1984. £10 (surface mail), £12.25 (airmail). Reviewer: P.Le. Grubb Ok Tedi, by William S. Pintz. London, Mining Journal Books Limited, 1984. 206 pp. £19 (surface mail), £22.25 (airmail). Reviewer: R.P. Plewman 2. Publications of the Canadian Mineral Policy Sector Lime by D.H. Stonehouse. 5 pp. Phosphates by G.S. Barry. 9 pp. Statistical summary of the mineral industry in Canada. 77 tables. Talc by M. Prud'homme. 6 pp. Zirconium by M.A. Boucher. 6 pp. Cement by D.H. Stonehouse. 13 pp. Gypsum and anhydrite by D.H. Stonehouse. 7 pp. Regional review by T.M. Buch. 12pp. SaltbyG.S. Barry. 7pp. Silicon, ferrosilicon and silicon carbide by D.G. Law-West. 6pp. SulphurbyB.W. Boyd. 9pp. Mineral Report 31. Canadian Minerals Yearbook 1981. Available from the above address at $40.75 per copy. 3. Mintek reports Report M18D The recovery of pyrite and gold from acid-leach residues from the Merriespruit Gold Mine. (First issued Feb. 1982; reissued Mar. 1984). Report M2OD The separation of ore from Cooke into high- and lowgrade fractions. (First issued Feb. 1982; reissued Mar. 1984). Report M33D Explanatory tests on the reduction of the sulphur content of sponge iron. (First issued Apr. 1982; reissued Mar. 1984). Report M43D Beneficiation tests on andalusite-bearing shales from a farm near Thabazimbi. (First issued Aug. 1982; reissuedMar. 1984). Report M129 The determination of tin, niobium, and tantalum in pegmatite by X-ray-fluorescence spectrometry. ReportM131 The determination of copper and nickel in iron- and chromium-bearing materials by a pressed-powder technique and X-ray-fluorescence spectrometry. Report M135 The installation of a 100 kV A plasma furnace at Mintek. The selection and installation of a 100 kV A a.c. plasma Report M136 The determination of gold in activated charcoal by use of a loose-powder technique and X-ray-fluorescence spectrometry. Report M140 The effect of physical and chemical factors on the corrosivity of a synthetic mine water.

Jan 1, 1984

By Charles Schwab

WHEN I leave this life, as an employer of labor there is no one thing that I want so much to be engraven upon my monument as the fact that I have been one of the men who have worked, whether with my brains or my hands, for the advance-ment of industry in the United States, and to be regarded, as I should like to be regarded by labor with love and kindly remembrance for our years of association. In my relationship with my employees, I have always contended that every man should be paid for what he does. I will not employ or be associated with any kind of labor of which the organization insists that a man shall receive a fixed sum of money for his day's wages, however poor or good his day's labor may be. What applies to the common laborer applies equally well to the management, the brains of an industrial establishment. I have always thought of industry as a three-legged stool, with capital, management and labor as the legs. All three legs of that stool must be there before that stool can stand up. If you take any one of those legs away, it is going to topple over. The. three must stand together for successful business accomplishment. I believe that a man who has his labor to sell, to put it plainly, has just as good a right to bargain for the best price for that labor as those who employ him. It is a perfect right for him to do so. If the government of our United States is right, our method of handling labor in our Bethlehem plants is right because it is representative and democratic. We have our labor elect delegates; elect representa-tives from their own ranks, who shall meet frequently. That constitutes, as. it were, the House of our great Congress in Washington, the industrial house. We have our management, who represent the Senate, who meet independently. Working men have learned to express their views freely as to whether they are treated fairly and whether conditions are right or wrong.

Jan 12, 1922

By Roswell Johnson

ALL strata not yielding oil or gas in commercial quantities or a corresponding amount of water may be called dry in a wide sense. In petroleum geology,, however, we may exclude all sands of too low or fin porosity to yield gaseous or fluid contents to the hole drilled in the sand before any original pressure that its contents may be under is disturbed. Most rocks are of this class and they are not reservoirs in our definition; their "dryness" is wholly a matter of course. What are the contents of the pores or what is the exact porosity of such rocks is of almost no concern to us, for economically they are "dry." What does interest us is the content of a rock having sufficient porosity and the pores of sufficient size to yield oil or gas in commercial quantities, if they were present under original pressure: Dryness of these reservoirs is a matter of supreme practical importance. Three views current as to such dryness seem, to me, to apply in a few cases only. It is the purpose of this paper to give reasons for this position and for believing that, in ordinary sedimentary rocks, there is only rarely a reservoir of competent porosity and undisturbed pressure that is dry in the sense of not yielding water, oil, or gas when first penetrated. 1. Gardner1 writes of some Kentucky sands, "There has never been present any salt water or other water in the sand." Absence of water cannot demonstrate this position. It is necessary to show that the rocks were not laid down in water, but in air, and that they became so enclosed, while still above the water-table of the, ground water, that water has not been able to enter since. Most of these sands, and certainly the productive limestones, were deposited in water; and such sands as have been commercially productive show no reason for believing that the overlying shale or limestone was not laid down progressively from one direction and in water that would have flooded it. No adequate explanation has been offered for this hypothesis, which is so inherently improbable.

Jan 1, 1920

By Jeffrey D. Eisenman

FRP is a proven material for the solvent extraction processes of copper production. There is a history of successful applications of FRP piping and equipment in hydrometallurgical processing. The performance of FRP equipment has not always been consistent, but at no fault of the material. Its non-metal attributes and behavior vary from those of more typical materials of construction, such as steel and alloys. FRP is a mainstay material in many areas of solvent extraction and electrowinning and yet not well understood by all. We will discuss the critical concerns, which are key to reliable performance of FRP systems. This paper will include discussion of key elements, which are fundamental to reliable FRP piping design and considered best practices. Essential design and construction considerations to maximize reliable service life of FRP equipment, such as thickeners and process vessels, used in copper extraction and processing, will be discussed. Additionally, we will expose potential pitfalls and share lessons learned from previous copper processing plant projects, which can aid and impact other copper processing projects to ensure best system performance and reliability. INTRODUCTION The corrosion resistant attributes of fiberglass reinforced plastics (FRP) make it an attractive and cost effective material of construction in corrosive service applications that are found in copper processing. FRP is used all over the processing plant in seawater, brine and sulfuric acid services where the corrosive nature of these services would challenge most ferrous materials and coatings. FRP is a fully customizable material to meet the specific needs of each service and process. FRP piping and equipment can be found throughout the hydrometallurgical process, in the acid plant, desalination, leaching processes, solvent extraction and electrowinning to name a few. Beyond its superior corrosion resistant characteristics, FRP can be made abrasion resistant by introducing particulate additives into the resin, such as silicon carbide and alumina oxide. Because many of these services have combustible organic elements in the flow streams with accompanying safety concerns, the linings can be made conductive with carbon fibers to dissipate static charges that might collect on the surface of the equipment otherwise. Further, FRP can be made flame retardant as well, where flammability may be of concern.

Jan 1, 2019

By E. G. Bailey

The bituminous coal industry faces a real problem, if it desires to retain the position in the power-generation field to which it is economi-cally entitled. More power is probably produced today for electrical energy, for steam-driven and steam-heating industries and processes, for transportation by rail, water, highway and air, collectively, than ever before, and yet the total bituminous coal production has decreased about 38 per cent, from 575,000,000 tons in 1926 to 357,500,000 tons in 1934. It is not the intention of the writer to recommend coal as a fuel for automobiles and airplanes, but rather to point to these forms of transpor-tation as being responsible in a very measurable degree for reducing the coal consumed by railroads. Petroleum products may still further reduce consumption of locomotive fuel through the extension of the use of Diesel-driven trains. Oil-burning steam-driven locomotives are replacing coal in some places, where railroads operating high-speed pas-senger trains are willing, temporarily at least, to pay a premium for the fuel, that is low in ash and produces less smoke and practically no cinders. In the navy and ocean-going passenger ships, oil is so firmly estab-lished, and has such definite advantages over coal as formerly fired, in steaming radius, in ease of bunkering, cleanliness, and reduction in firing labor, that very outstanding developments in the handling and burning of coal will be required in order to replace oil. For freighters on the Great Lakes, coal is the logical fuel, but there is great and immediate need of radical improvements in its use, else that market also may be lessened. It is not within the scope of this paper to discuss in detail bitumi-nous coal for either locomotive or marine use, but, rather, generation of power in stationary plants, consisting of electrical generating stations and that very large group of miscellaneous industrial plants, such as paper, rubber, textile, steel and other industries that use electrical, mechanical, and steam power, derived from either hydro or some form of fuel.

Jan 1, 1935

By C. T. Bischoff

This paper describes the results of testing with colorimetric methods, using "dithizone", soil samples taken over various known copper and zinc deposits covered by glacial till. Variation in results is shown for different depths and types of overburden as well as grade and type of deposit. Limiting factors for the practical application of this work are discussed. The method has proved successful for copper and zinc deposits under clay and fine sand with depths up to at least 30 ft but fails in coarse sand and gravel unless depths are very shallow. Swamps require penetration to the underlying subsoil for sample material. DURING the past few years geochemical testing for traces of heavy metals in water, soil, rock, and vegetation has aroused increasing interest. Various techniques for field and laboratory determinations have been described in the literature, as have some of the results of application. However, little information has been published regarding application to glacial terrain. Over 90 pct of the Canadian Shield is overburdened, resulting in high costs for mineral exploration once the outcropping ore deposits have been found. This has been largely responsible for the widespread application of mining geophysics in Canada, permitting concentration of effort on area or zones considered most favorable. However, geophysical interpretation has its limitations, since at least 90 pct of the structures indicated thereby contain no valuable minerals. A more direct approach is therefore highly desirable. If underlying base metal mineralization can be detected by sampling soil or vegetation at moderate cost this should prove of great help in locating new discoveries or extending known ones. A large proportion of Canadian ore deposits contain appreciable copper or zinc, even where these are not the principal economic metals. Consequently the field of application is a broad one. This paper deals with investigations along these lines with particular emphasis on soil sampling. The problems involved from the start were: 1—Which types of glacial soil, if any, would best lend themselves to testing, and conversely which types might be considered relatively hopeless? 2—Through what depths of overburden could significant mineralization be detected? 3—What sampling techniques would prove economically applicable? This included minimum depth of sample and maximum spacing that could be allowed.

Jan 1, 1955

By Dale A. Sketchley

"Abstract - Large differences in gold content between rock fragments or small volumes of unbroken rock, commonly referred to as the nugget effect, are related to sample and subsample weights, crushing and pulverizing sizes, and density, shape and size distribution of gold grains. Gy’s sampling theory, which relates gold grain characteristics to sample weight, fragment size, and error, provides a method of estimating a sampling constant that quantifies deposit characteristics that contribute to the nugget effect.Sampling control tests provide methods for determining the sampling constant. Sampling control charts, comprising nomographs that relate sample weight, error and particle size, use the sampling constant to optimize sample weights and comminution sizes, and to minimize the variability introduced by incorrect or inadequate sampling and sub-sampling procedures. The sampling constant is useful in classifying ores into arbitrary categories according to expected sampling difficulties. Spatial variations in the sampling constant can be used to aid in defining ore types for modeling geological domains, which should have unique sampling protocols. Examples that illustrate the relationship between the sampling constant and expected sampling problems, and the spatial variation of the sampling constant, are given for various deposits. Case histories of sampling programs are presented.Quality control procedures consist of monitoring sample contamination amd accuracy and precision of analytical results. Accuracy, precision and contamination are monitored by including standards, duplicates and blanks into batches of samples being analyzed. Analytical results of standards and blanks are plotted on a batch-and-time basis with control lines at plus or minus two/three standard deviations as confidence limits of the accepted round-robin value. Examples are given that illustrate a laboratory system in statistical control and the various types of problems encountered when interpreting quality control data. These include sample transcription errors, degradation, contamination, sampling errors, detection limit problems, instrumental drift, lack of statistical control, laboratory bias, procedural problems and data tampering.Where bias is negligible, precision, as a function of concentration, can be obtained from duplicates using the Thompson-Howarth precision algorithm, which also allows calculation of the practical detection limit. Examples are given that illustrate variations in precision, with grain size, for different types of duplicates, as well as mineralogical changes and sampling errors."

Jan 1, 1998

By N. H. MacMillan, O. C. Dias

Recent work by Westwood et al. (reviewed in Refs. 1-6) has established that many rocks, minerals, ceramics, and glasses exhibit phenomenologically similar chemomechanical (Rebinder) effects when deformed in different liquid environments, apparently as the result of chemisorption-induced variations in their near-surface flow and flow-dependent fracture behavior. In particular, it appears that there exists an empirical, but apparently general, correlation between the near-surface flow stress of an inorganic nonmetal and its surface charge- namely, that such a solid is hardest at its zero point of charge (i.e., when its zeta potential [ ] = 0) and softens as [ ] increases, regardless of the sign of zeta. Moreover, because near-surface flow and fracture phenomena are two of the important determinants of the rates of machining and comminution processes, both Westwood et al. and others7 have been able to use this so-called "[ ]-correlation" to develop cutting fluids and grinding aids that in many instances have given rise to several fold increases in performance. In addition, Westwood et al. have demonstrated that both aqueous and organic environments can give rise to similar improvements in cutting rate for a given combination of tool and workpiece, provided that both impart the same surface charge to the work- piece (i.e., transfer the same number of electrons to or from its surface). This last finding implies that in any application it should always be possible to find some cutting fluid that is at once effective, cheap, nontoxic, and nonpolluting. Thus, reports of apparently similar environmental influences on the mechanical behavior of diamond,8 certain organic crystals and polymers,9-14 and coa1-15-21 suggest that it is pertinent to ask: (a) whether the [ ]-correlation (or any analogous relationship) extends to coal; and (b), if so, whether this relationship can be used to guide the development of superior aids for grinding coal. Accordingly, correlations have been sought between (1) the zeta potentials, (2) the hardnesses, and (3 and 4) the drilling and grinding characteristics of coals of different rank in different aqueous and organic environments. This paper reports the results of that search.

Jan 1, 1980

By John C. McKay

"The five papers which follow, under the heading of ""Technology Transfer-Universities to Industry"", were originally presented at the 20th Annual CIM Conference of Metallurgists in Hamilton, Ontario. They are a unique group of papers, unique because each paper is concerned with applied research done wholly or partly in a university environment and then translated into industrial practice.Universities can rightly be regarded as one of our nation's greatest resources-a veritable storehouse of knowledge and expertise. Yet, too often, this resource is overlooked or, at best, sparingly used by Canadian industry. Of course, university-based research cannot supplant industry-based research, nor vice versa; each type of research activity has its proper role in the over-all process of technology development.University-based scientists are best equipped to conceptualize, innovate, determine viability of basic premises and to verify these at the bench or small pilot-plant level. Industry based scientists are best equipped to develop ""bench-scale"" innovations into mature manufacturing practices. Thus, university-based scientists and industry-based scientists do not compete with, but rather complement, each other. Active, relevant university research enhances industrial research provided good communication between the two ""solitudes"" is continually nurtured.Good communication between industry and university is a prime objective of CSIRA/ACRIS (Canadian Steel Industry Research Association /Association Canadienne pour la Recherches dans d'Industrie Siderurgique), The directors of CSIRA/ACRIS foster improved communication by making regular visits to universities, by sponsoring projects and by providing lists to professors of uncharted areas where basic research is needed. More can be done to improve communication between industry and university, and it is the intent of the Association to do more.The five papers sponsored by CSIRA/ACRIS are examples of good communication and healthy cooperation. It is interesting to note when reading these papers that the cooperation arose, in each instance, as a result of different circumstances. However, there is a common thread and it is personal acquaintanceship-the university scientist/professor and the industry investigator/manager knew each other prior to the initiation of the project."

Jan 1, 1982

By Thomas Read

PERSONNEL work is a term recently introduced to cover the great variety of activities in industrial work that deal with the human factor. Much attention has been focussed upon individual phases of personnel work, such as accident prevention, sanitation, "welfare" work, reducing labor' turnover, and so on. In most cases these activities have been carried on as though they were distinct and separate fields; as a matter of fact, they are only different phases of the single problem of human engineering, and each has important and fundamental relations with the others. Thus, for example, high labor turnover is one of the most .important causes of a high accident rate, and unsatisfactory housing conditions are an important cause of labor turnover. In the early stages of the study of these problems, it was necessary to take them up separately; the time has now arrived at which it is desirable to consider them as a whole in order to bring them into the right relation to each other. When thus considered as phases of an interrelated whole, they may be grouped as personnel work. A discussion of the importance of personnel work as a means of in creasing dividends in industry may be objected to by some as a too materialistic way of looking upon work that is humanitarian. Nothing could he more mistaken than such an opinion. Humanitarianism, per se, has no place in industry, and nothing is gained and much is lost in pre tending that it has. The only reason why a corporation engages in business is to make profits, and any activity of the corporation that does not tend either directly or indirectly toward that end is poor business. It is equally poor business to overlook any activities that do tend indirectly to the making of profits. On this basis, personnel work can be justified as a corporate activity; there is no justification whatever for abstract humanitarianism from the business standpoint. One characteristic of the American workman is a general high level of intelligence, and it is an insult to intelligence to ask a man to believe that anything so impersonal as a corporation is really desirous of benefiting

Jan 10, 1917

By Paul Tyler

FULLY a decade ago, demand for ground mica began to exceed supplies of scrap mica from manufacturing operations and of waste block from feldspar and sheet mica mining in the United States, with the result that in recent years the market has absorbed larger and larger quantities of mica recovered as a by-product from clay washing,1 as a joint product with kyanite,2 and by grinding schists. So far, only schists that contain a large percentage of mica have been utilized for making ground mica, but already there has been a good deal of wishful thinking with regard to recovering mica as an aid to the prospective working of low-grade gold ores and ores of certain base metals. With wet-ground mica selling at $60 to $100 a ton and even dry-ground mica worth over $20 a ton, many ores that could not be considered as otherwise workable under present conditions will show commercial possibilities if they can be made to yield even a relatively small percentage of salable mica. An interesting paper might be written on the coming role of industrial minerals as joint products of metal mines, It is largely a matter of mar-kets. Many years ago I watched the mess left behind the gold dredges in the mountains of Colorado and thought of the Denver sand and gravel operators who prided themselves upon their canniness in providing devices for catching gold merely as an incident to their regular business of selling what we miners classed as "tailings." Nowadays almost every milling or mining operation near settled communities finds use for at least part of its waste for road material or concrete aggregate and several eastern iron mines have gone into the crushed-stone business. Promoters now mention fertilizer "filler" as potentially salable at all the way from $1 to $10 a ton, or whatever is needed to cover costs of mining and treating the "ore" and leave the metal values as "clear profit." In emulating the pork packers in their efforts to utilize "everything but the squeal,"

Jan 1, 1938

By Debra W. Struhsacker, Jean Kiel, Jeffrey Thatcher

3.1 INTRODUCTION As heap leach precious metal projects become increasingly common in the United States, federal, state and local regulatory agencies are beginning to take a closer look at the short- and long-term environmental consequences of this recovery technology. From an operator's point of view, there is seemingly a confusing regulatory maze to be navigated and a plethora of permits and approvals to be obtained prior to commissioning a heap leach operation. The degree of difficulty associated with obtaining permits for a heap leach project depends largely upon the state in which the project is located. Permit acquisition is generally easiest in those states most familiar with heap leaching technology. For example, heap leaching is well understood in Nevada, and heap leach operations are relatively easy to permit, although permitting conditions in Nevada have recently become more stringent. However, many states are just beginning to become familiar with heap leach operations. Many of these states such as Idaho, Colorado, South Dakota, Oregon, Montana, Washington and South Carolina are in the process of drafting regulations and establishing guidelines for heap leach projects. In most cases, these regulations specify design and operating criteria as well as reclamation and decommissioning procedures. This chapter provides an overview of the regulatory and permitting aspects of heap leach operations. Permitting requirements for projects developed on federal land are discussed in detail. 'The state and local regulatory atmosphere and permitting requirements for various states are also presented. The chapter concludes with a generic permitting strategy. 3.2 KEY ENVIRONMENTAL CONCERNS The primary concern of most local, state, and federal regulatory agencies is the use, storage and transport of sodium cyanide (NaCn), and potential cyanide contamination of surface and groundwater resources. The toxicity of cyanide to people, fish and wildlife is also an important issue. Unfortunately, in the public eye, cyanide heap leaching has some emotional impacts similar to those associated with radioactivity and uranium mining. This perception and the general lack of understanding of cyanide can lead to unnecessary concern about cyanide contamination, further complicating the regulatory environment.

Jan 1, 1988

By Richard W. Lawrence, Richard Poulin

"Numerous processes co-exist for metal extraction and for metal removal from effluents of mining operations. Each process enjoys an economic advantage, including environmental cost and benefit, if utilized in a specific situation. This applies equally to biohydrometallurgical processes. This paper will analyze four types of biohydrometallurgical processes for their economic and environmental attributes: biooxidation of refractory gold, extraction of copper from sulfide, metal removal from effluents by active sulfate reduction, and metal removal by the use of wetlands. By examining the economic and environmental advantages of these processes, generalizations can formalized and it becomes possible to define niches of application where biohydrometallurgy can be considered. Our analysis shows that biohydrometallurgy can be efficient at small scale, be more environmentally friendly than conventional technologies and is relatively easier to operate. The higher financial risk associated with unproven technologies at the commercial scale is being eliminated as biotechnology-based plants are put into production.IntroductionBiotechnology can be described as the rational exploitation of the activities of living cells or parts thereof, requiring an integrated multidisciplinary approach between biological and technical disciplines. Microbiology, biochemistry, botany, molecular biology, chemistry and engineering all contribute to practical applications in the extraction, manufacturing and service industries, and in environmental management. Considerable commercial success of biotechnology has been achieved in several sectors, including health care, agriculture, forestry and aquaculture.Over the past 40 years, industry, research organizations, government laboratories, and universities in a large number of countries have participated in investigating the utilization of biotechnology applications in mining. Today, several technologies are used commercially in well understood and engineered systems which can be grouped under the term biohydrometallurgy. Many more technologies have been demonstrated at laboratory or pilot plant scale. Although initial developments and commercial applications were aimed at metal extraction, the dramatic increase in environmental awareness, the practice of sound environmental management demanded by more stringent regulations over the past decade, and the need for low cost treatment in perpetuity, has led to serious investigation of biotechnology for environmental control. In addition, increasing power costs, lowering of ore grades, and decreasing commodity price in real dollar terms require the use of highly efficient and competitive extractive technologies."

Jan 1, 1998

By Paul M. Tyler

FULLY a decade ago, demand for ground mica began to exceed supplies of scrap mica from manufacturing operations and of waste block from feldspar and sheet mica mining in the United States, with the result that in recent years the market has absorbed larger and larger quantities of mica recovered as a by-product from clay washing,1 as a joint product with kyanite12 and by grinding schists. So far, only schists that contain a large percentage of mica have been utilized for making ground mica, but already there has been a good deal of wishful thinking with regard to recovering mica as an aid to the prospective working of low-grade gold ores and ores of certain base metals. With wet-ground mica selling at $60 to $100 a ton and even dry-ground mica worth over $20 a ton, many ores that could not be considered as otherwise workable under present conditions will show commercial possibilities if they can be made to yield even a relatively small percentage of salable mica. An interesting paper might be written on the coming role of industrial minerals as joint products of metal mines. It is largely a matter of markets. Many years ago I watched the mess left behind the gold dredges in the mountains of Colorado and thought of the Denver sand and gravel operators who prided themselves upon their canniness in providing devices for catching gold merely as an incident to their regular business of selling what we miners classed as "tailings." Nowadays almost every milling or mining operation near settled communities finds use for at least part of its waste for road material or concrete aggregate and several eastern iron mines have gone into the crushed-stone business. Promoters now mention fertilizer "filler" as potentially salable at all the way from $1 to $10 a ton, or whatever is needed to cover costs of mining and treating the "ore" and leave the metal values as "clear profit." In emulating the pork packers in their efforts to utilize "everything but the squeal,"

Jan 1, 1938

By Howard A. Meyerhoff

Nonmetallic rock and mineral products are so diversified that any generalizations regarding the industries based upon them are of doubtful value and can be misleading. They are geared to every phase of the national economy and respond sensitively and immediately to any economic change, but the responses vary with the individual products. They are also affected by political and competitive factors to a degree that is disconcerting and, at times, ruinous to operators, owners, and stockholders of mineral properties. It is not unusual to find these special factors functioning in reverse of general trends insofar as individual products are concerned. As this summary is being written in the final weeks of 1949 production statistics for the year are not complete, but it is obvious that few, if any, new production records will be set, and that 1949 level, will, in general, be lower than those of 1948. The decline in output is not alarming and reflects in large part the tendency of users, who have been finding sources of supply more dependable to rely on prompt deliveries rather than on inventories to meet immediate needs. Except for the government's program of stock piling which, insofar as it has worked at all, is of more direct interest and benefit to foreign than to domestic producers, industrial inventories have been further reduced, and the neater balance between production and consumption has freed capital for the manufacturer and has cut down the serious hazard of substantial inventory losses. There are no quantity products and only a few special products that cannot be supplied in quick response to current demands. Normal development of a few nonmetallic industries has been retarded by the government's unpredictable application and irrational interpretation of antitrust laws, and by extension of preferential tariffs to new countries and new products. Synthesis is likewise a potent threat. in certain fields, but otherwise it is difficult to make a review of 1949 read much differently from a review of 1948. Changes have been qualitative rather than quantitative, except for a few operations that have been pinched out by the relentless competition that characterizes many of the industrial mineral industries.

Jan 1, 1950