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By NEWTON B. KNOX

CHILEAN mining in the public mind is rightly associated with copper. Chuquicamata with its great hill of copper-bearing granodiorite as well as Sewell and Potrerillos with mineralized volcanic necks together can supply a good proportion of the world's normal necessities of that metal. Chile is an extremely long and narrow country, averaging only 109 miles wide. Its eastern frontier is the Andes and it is on the western slopes of these mountains that the great copper deposits have been discovered. West of the Andes a great longitudinal depres sion has permitted accumulation of nitrates and other soluble salts in the arid north; in the north center it is hidden by a series of cross ranges, but in the center a moderate rainfall makes it the country's most important agricultural region. In the south this depression is drowned and gives rise to a series of straits and fiords. This enormous cleft in the earth's crust is separated from the sea by a coast range of moderate elevation which in the south is represented by a series of islands and mushroom-shaped peninsulas

Jan 1, 1945

By R. J. Nankee

Recent on-going efforts to develop commercial coal cleaning beneficiation processes using chlorinated solvents-as the separating media will be described. True heavy media separations were performed on raw coal feedstocks, including Pennsylvania anthracite; Western, Eastern, and Midwestern bituminous; and lignite coals. Separation techniques included bath-type devices, cyclones, and liquid/liquid partitioning. Details on separation devices, removal of solvent, and recovery and recycling of solvent will be discussed. Projected costs of full-scale plants will be given for various coal sizes. A number of the coals evaluated are good candidates for beneficiation using chlorinated solvents. Coal beneficiation is desirable to provide needed coal quality. These needs include low ash fuels for coal water slurries and low sulfur fuels to meet emission regulations. In October of 1985, a paper, "Chlorinated Solvents for Coal Beneficiating"' was presented at the fall meeting of SME-AIME at Albuquerque, New Mexico. It reported the results obtained from various coals as feedstocks and of the separations using chlorinated solvents. These beneficiation results depended on true heavy media gravity and liquid/liquid partitioning separations. This paper will include detailed descriptions of the liquid/liquid partitioning process used in "Dow's Advanced Coal Cleaning Technology?2 and of the "Dow Solvent Recovery Technology.?3

Jan 1, 1987

By F. W. Lee

Operating engineers and mining executives are interested in the science of applied geophysics, but are looking for a simple and understandable exposition of its problems, instead of dissertations which are becoming more and more involved and increasingly difficult to comprehend. It may be well to discuss the goal, the attempted methods of reaching it and the psychological motive, if any, tack of the science. Where does the subject of applied geophysics stand from the viewpoint of (1) the physicist, (2) the mathematician, and (3) the geologist? Fundamentally, the science aims at a differentiation of subterranean geology with the object of finding useful mineral products by the study of gravitational, magnetic, seismic, electric, and other fields which may be associated with the materials naturally or which may be applied to them. The more skillfully these fields are recognized, applied, and analyzed the greater will be the possibility of interpreting results in a way that will be remunerative both economically and scientifically.

Oct 1, 1931

By He Zhi-jun, Ning Zhe, Pang Qing-hai, Zhang Jun-hong, Zhan Wen-long

The effect of microwave irradiation on grinding property of coal was studied by using Hardgrove grindability index tester. Superior grindability of coal was obtained to varying extent after microwave irradiation treatment. The variation in microstructure of pulverized coal during microwave irradiation was observed by utilizing scanning electronic microscope (SEM). The results indicated that the different microwave absorbance of minerals and carbon matrix led to cracks on their interface, by which coal particles were further pulverized and therefore the granularity of coal powder was reduced. Due to the different formation process of various coals, bituminite and anthracite are very different in physical and chemical properties. According to the content of coal pulverization, it can found that microwave irradiation has a stronger pulverizing effect on bituminite in comparison to anthracite.

Jan 1, 2016

By S. J. Schatzel, J. D. Addis, V. Gangrade

In longwall mining, ventilation is considered one of the more effective means of controlling gases and dust. In order to study longwall ventilation in a controlled environment, U.S. National Institute for Occupational Safety and Health (NIOSH) researchers built a unique physical model called the longwall instrumented aerodynamic model (LIAM). The LIAM is a 1:30 scale physical model geometrically designed to simulate a single longwall panel. It has an 8.94 by 4.88 m (29 by 16 ft) footprint with a simulated face length of 220 m (720 ft) in full scale. LIAM is built with critical details of the face, gob and mining machinery, and scaled to preserve the physical and dynamic similitude. This paper discusses the gob-face interaction, airflow patterns within the gob, and airflow dynamics on the face for varying roof caving characteristics. Results are discussed to show the impact of caving behind the shields on longwall ventilation.

By Thomas Niehoff, Yin Qing, Wei Zhongling, Liu Yongguo, Zhang Deliang, Tang Le

The gold ore of Shandong Gold Mining (Xinhui) was a refractory ore, which contained multi metallic sulfides (ZnS and PbS etc.) and carbonaceous. The gold ore concentrate came into leaching process and thickener and zinc replacement to recover gold. In order to improve gold recovery, the GOLDOX™ hydrometallurgy process was studied in Shandong Gold (Xinhui) by bench scale and 6 month plant scale test supported by Linde Gas. It was shown that the process promoted the leaching kinetics and improved gold recovery. The residue grade reduced 0.22 g/t in average after oxygen was applied. This indicates an operating profit increase 850,000 yuan/a in the plant. It was setting a good example for similar gold mine plant and would promote the oxygen application in Chinese gold mining industry.

Jan 1, 2015

By Shangyong Lin, Wei Sun, Weiping Liu, Muhammad Azam, Junfeng Cheng, Yujie Zhao, David Asubonteng, Michael Ngoie

Copper concentrates have wide application in global smelting operations, comprising primarily of chalcopyrite (CuFeS2) as the principal mineral, accompanied by chalcocite (Cu2S) and bornite (Cu5FeS4) as secondary copper-bearing minerals. However, these concentrates frequently harbor detrimental impurities, notably fluorine ions, which can cause various complications during the smelting process. Moreover, an elevated fluorine content in copper concentrates may entail financial penalties and sales constraints. This review conducts a comprehensive analysis of existing methods for the removal of fluorine, presenting a nuanced assessment of their merits and demerits. It also provides valuable insights into the current landscape of fluorine elimination from copper concentrates and pinpoints pivotal areas warranting future investigation. This review endeavors to serve as a pragmatic resource for researchers and industry professionals operating within this domain.

Jan 1, 2024

By Langdon T. Mitchell, Karl Ingmarsson

The title is not referring to jewelry; nor is it about diamond core drilling. This article is instead about an emerging application for diamonds, hard rock percussive drilling with diamond drill bits. Diamond’s outstanding wear resistance has long been taken advantage of in core drilling. However, until now diamond has been less successful in hard rock production drilling in the mining and quarry industry.

Jan 1, 1999

By Vladimir J. Ovdenko, Sergey N. Lazarenko, Evgeny L. Schastlivtsev

The term sustainable development shortly appeared in international use in the run of UNO Environmental Protection Conference held in Rio de Janeim in 1992, bears the concept, that evolution process ( associated either with a region or society) should provide mutual interests concern in three aspects - environmental, economic and social ones, admitting as well the fact , that environmental protection should become an integral part of each process and cannot be regarded separately. In this connection it seems quite reasonable to employ the principal of sustainable development, while creating the model of industrial mastering the territory constraint lands viewing their future, for a example, in rich mineral deposit's development. In Kuznetsk coal basin in Russia ( west Siberia) the development of a big coal deposit Erunakovsky is now being underway. The major part of coal will be mined with open cast method, resulting the number of local environmental adverse impacts' occurrence. In such a situation mastering of sustainable development model is given the top priority, demonstrating the essential result of its application in a form of possibility to define the best correlation between economically expedient and environmentally tolerable loads during coal mining. The given paper is an attempt to work out the main principals to approach the creation of sustainable development model in regard of the definite region case. To simplify the presentation of employed approach's main idea, the given below accepts as its component only one of many actually existing environmental profiles, that define mining pro- cess impact on environmental situation -the size of infringed (de- graded) lithosphere surface. Basically, the actually existed correlation between spheres. grounding the model of sustainable development - economic, environmental and social- is given in a form of nomogram under Fig.1. On the presented graph the prognostic values of broken lands relative extent within Erunakovsky boundary ( to be compared with total region area taken as 100%) are arranged on axis x". Axis "y- demonstrates the main values associated with complete economic background, making the intrinsic part of the principal for sustainable development, i.e. annual coal output for the given area. It's top, used in assessment value relates to actual showings implied for the study region project and quantifies 60 min. tons. While regarding the social facet of principal for sustainable development, the applied mode to separate social issues into two types - one profiling a welfare standard of living and the other. pertaining the way environmental situation contributes to the degree of &ologica-1 comfort in people's living was defined as the most expedient and the most adequate in the matter of reflecting the actual terms of vital activity of the society. In accordance with the cited above the economic level showings are plotted on the graph on "-x” axis, while "-y" one obtains the values associated with the point of ecological comfort presented in conventional units. For the maximum possible conventional point of living (corresponding in nomogram to 1.0 value) a welfare level secured with industrial region economic activity revenue was assumed in case the top planned annual amount of coal is delivered ( 60 min. tons). While studying the index of public economic welfare, environmental conditions corresponding level in its original state i.e. prior to any industrial work carried in the region, was adopted as its top possible conventional rating (1.0). The given nomogram displays the integrity of x-f(y) type interrelations plotted on the basis of four separate dependencies, precisely a) the size (area) of infringed earth's surface as a function of coal output in the region; b) subordination of ecological comfort of people's living to the degree of lands infringement; c) interconnection of economic and environmental components of people living; d) interconnection of economic level of people's living and the amount of coal mined in the region. Linked to a single unit, these separate plain dependencies create, as seen from the graph, a more intricate system of bonds, that affords during defining or changing this or that system parameter to secure undergoing changes, that occur to other parameters of the system. The mentioned reason made it possible to consider and drive to mutual conformity ( as far as it is possible) all parameters values for the defined system's relations, that in their turn indicate the concern of other aspects of a sustainable development principal. According to the graph, in order to get not more than 50% of infringed land left after the deposit's mining, it is advisable to ex- tract not more than 40 min. tons of coal annually, gaining in this case the level of ecological comfort for living in the amount of not

Jan 1, 1996

Australia as a leading producer of mineral sands has also occupied a leading position in many areas of research'in the processing and applications of these minerals. Research in upgrading ilmenite to produce synthetic rutile has resulted in the develop- ment of many processes, e.g,., Becher, Murso, Chlorine Technology, and ICI processes. Studies on the reducibility of ilmenites, aqueous leaching of reduced ilmenites, Fe-Ti-O system, leachability of natural and treated ilmenites in hydrochloric acid and selective chlorination of iron from ilmenites have been carried out in order to develop and improve the efficiency of the above processes. While research on the processing of zircon sand to produce high purity (99.99% ZrO2 zirconia powder and zirconium chemicals started only recently, research by CSIRO in the early 1970s led to the discovery of the phenomenon of transformation toughening in partially stabilized zirconia (PSZ) ceramics. Australia, with very significant resources of lanthanide-containing ores, pro- duces substantial quantities of monazite each year but research in processing and appli- cations of rare earths was neglected in recent years in this country. However, research to improve processes for the recovery of rare earths is now under way and studies on the production and testing of Nd-B-Fe magnets which are 1.5-2 times stronger than the strongest magnets (Sm-Co) currently available, have also commenced.' An overview of the research in the pro- cessing and applications of mineral sands during the last two decades in Australia and its implications for the industry are pre- sented in the paper.

Jan 1, 1986

By M Yahyaei, P Knights, M S. Kizil, J Qu

Digital Twins (DTs) are transforming business operations across many industries through their accurate representations of physical entities enabled by IoT technologies.

Sep 1, 2024

By Jean-Paul Drolet

"The ultimate aim of the Law of the Sea Conference, held under the auspices of the United Nations, is to ensure that all aspects of the use of the sea are covered by international law. The question facing the nations of the world can be stated as: "" Who will control and benefit from the use and the wealth of the sea?""The United Nations Conference on Law of the Sea - known as UNCLOS - which reconvened in New York during the latter part of August 1978 was the third such Conference in the UN's history. The concepts of sovereignty over the territorial sea and freedom on the high seas have remained fundamental to the international law o f the sea until our time. The legal regime based on these two concepts developed initially from state practice meant that the unilateral actions taken by one or more countries were eventually accepted and followed by others.It was not until 1958, during the first Geneva Conference on the Law of the Sea (pursued in a second Conference in 1960) that the Law of the Sea was codified and modified to a certain extent by the then independent nations of the world in the four multilateral conventions on territorial sea and contiguous zone, continental shelf, high seas, and fishing and conservation of living resources.A third Conference got under way many years later when the members of the UN met in New York at the end of 1973 for preliminary discussions . This meeting stemmed largely from the need to fill gaps in existing international legislation which did not cover the new uses of the sea. The Conference was subsequently reconvened a number of times - in Caracas (1974), in Geneva (1975) and twice in New York (1976) for what was called "" substantive negotiating sessions."" A sixth session was held in New York in 1977; a seventh, held in Geneva at the beginning of 1978, recessed and reconvened in New York at the end of August 1978. This is what is referred to, in international jargon, as the seventh session of the Third United Nations Conference on the Law o f the Sea. The following dates are the principal markers of a saga which began some twenty years ago with the purpose of regulating the use of the oceans."

Jan 1, 1981

By Noel S. Christensen

COBALT is a silvery white metal with a slight bluish cast, strongly resembling nickel in its appearance and properties, notably its resistance to corrosion, although its alloys with other metals differ quite decidedly in their properties from those of nickel. The name cobalt was derived from the German "Kobold" meaning goblin and this came to be applied to the cobalt minerals which, although they resembled ores, did not readily yield metal when smelted by the primitive processes available in the Middle Ages. Cobalt minerals were used as pigments by potters and glass workers before the Christian era. Cobalt blue glass was found in the tombs of the Egyptians and in the ruins of Troy, and many colors used by the ancient Greeks and Romans contained cobalt. The ancients were entirely unaware that the colors they used were caused by cobalt and the metal itself was only isolated about the middle of the eighteenth century by Brandt although the preparation of cobalt compounds had been carried on in a small way ever since the opening of the silver-cobalt deposits at Schneeberg, Germany, in 1470. The metal is fairly hard, with a density when pure of 8.81 in the cast state and 8.92 after working. The commercial grade of cobalt has a density of about 8.75 in the cast state. The atomic weight is 58.97. The Brinell hardness of the pure metal is 124; that of the commercial grade varies from as low as 100 to as high as 138, depend¬ing upon the impurities present. Pure cobalt has a sharp melting point at 1478°C. The tensile strength of the pure metal in the cast condition is said to be higher than that of any other pure metal. Kalmus gives it as 34,400 lb. per sq. in. for cast unannealed metal; the effect of annealing at 850 to 900°C. is to raise the strength slightly. The yield point is close to the ultimate strength and the reduction in area and elongation are both low. Mechanical working raises the tensile strength of pure cobalt rapidly and in the form of wire it will be over 100,000 lb. per sq. in. The presence of small quantities of carbon in the commercial metal raises the tensile strength to as high as 61,000 lb. per sq. in., the reduction in area and elongation being raised at the same time to approximately 20 per cent.

Jan 1, 1933

The value of processed materials of mineral origin was estimated to have exceeded $310 billion in 1990. U.S. raw nonfuel minerals mine production in 1990 was estimated at $33 billion, a 3.1 % increase over that of 1989. The value of minerals production increased in all but 3 of the last 30 years. The metals component of production value has fluctuated much more than the industrial minerals component. This reflects the greater volatility of metal prices. In 1990, total employment in metal mining continued the increase that began in 1987. This growth was partially offset by a slight decline in employment in industrial mineral mining, resulting in an overall in-crease of 1.1 % to 179,100 in 1990. Continuing high (by historical standards) metal prices led to expansions at some mines, as well as opening or reopening of additional mines, resulting in increased employment.

Jan 1, 1991

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 E. Nejati, S. Khoshkooei, V. Firouzdor, M. Akbari, F. Khomamizadeh

In this study the effects of Si content on mechanical and thermal fatigue properties of Al-Si casting alloys were investigated. Repeated heating and cooling cycles were applied on the samples at 230°C to develop thermal fatigue cracks. Crack growth mechanisms and microstructural influences were investigated by optical and scanning electron microscopy. Thermal fatigue behaviors were improved successively by increasing of silicon content up to 7wt%. However, addition of more than 9wt% silicon decreased the thermal shock resistance of the alloy. Silicon contents of about 9wt% presented the best mechanical and thermal fatigue resistance in the alloy.

Jan 1, 2006

By Desiree Willis

At 6 percent downgrade to a low point beneath California?s Sacramento River, the Lower Northwest Interceptor Sewer was a difficult project from the outset. Project owner Sacramento County Regional Sanitation District (SRC-SD) planned to excavate the V-shaped tunnel in two sections using an earth pressure balance (EPB) machine in soft ground. Muck removal, due to the steep downgrade, was a tricky proposition. ?We did look at muck cars, but determined they were not the best option due to the relatively steep slope of the tunnel alignment. The safety benefits of conveyors on this job were obvious, as there were not the potential hazards associated with muck cars traveling on an incline or derailing,? said Steve Norris, senior civil engineer for SRCSD The successful project represented one of the first instances of a conveyor system being used for a soft ground tunnel boring machine (TBM) application. Several projects in California, including a recent tunnel completed in 2009, have highlighted a growing acceptance of conveyor muck removal in a variety of ground conditions. Conveyors offer higher system availability than more common methods, such as muck cars, as they allow for continual operation of the TBM. The design of conveyor systems must, however, take into account the differences in material between soft ground and hard rock, including belt cleaning features, sealed transfer points and other elements.

Jun 1, 2010

By Timothy Fogarty, Gregory Poole, Roger Reeder, David Switz

This project involved the construction of a new pump station and intake structure at an existing water treatment facility. Although the project involved a significant amount of rock removal, the specifications said no blasting.

Jan 1, 2012

By K. A. McDonald

This paper will describe the experiences of Hibernia Holdings, Inc. in constructing a mineral processing facility in Mexico. It will attempt to set forth a guideline on what companies attempting to operate in Mexico can expect and what actions they can take. Ownership laws, import/export laws, labor laws, security, transportation and operating experiences will be discussed.

Jan 1, 1994

By B. Denby

sintered ores, to be removed by a pneumatic,

Apr 1, 1995