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By M. J. Sanzotti, C. J. Bise

This paper examines the potential for controlling longwall-induced subsidence by pneumatically backstowing waste rock into the void created by mining. The paper also examines scheduling the process as a unit operation of the mining activity. Based on a review of background literature and interviews with representatives of various mining companies, public-interest groups and state and federal regulatory agencies, a hypothetical case-study evaluation of pneumatic stowing at a southwestern Pennsylvania mine was conducted. The study indicated that current stowing technology cannot keep pace with the production potential of longwall systems in the United States. Further, at the mine used in this case study, concomitant stowing would reduce subsidence by only 50% of what would normally be incurred during full longwall caving, and the longwall coal-production rate would decrease from 3,630 t (4,000 st) per shift in the nonstowing case to 1,360 t (1,500 st) in the stowing case. A preliminary cost analysis reveals that pneumatic stowing would add from $5.79 to $11.57 per t ($5.25 to $10.50 per st) to the operating cost of producing coal at the case-study site.

Jan 1, 1997

By Cláudio Batista Vieira

Nos últimos dez anos grande atenção tem sido dada a tecnologia de realidade virtual, sendo sua aplicação cada vez mais marcante para o desenvolvimento de ambientes virtuais imersivos em diferentes áreas. Nesse trabalho é apresentada uma descrição da plataforma inovadora em realidade virtual de uma planta industrial de produção de ferro-gusa verde. O modelo 4D do alto-forno a carvão vegetal contempla o projeto detalhado de engenharia dos equipamentos e a partir da integração de softwares e hardwares foi modelado um ambiente tecnológico em realidade virtual de alto grau de realismo. Essa plataforma foi customizada para ser utilizada como Indústria-Escola de Educação Profissional para escolas técnicas, universidades, institutos de pesquisa, indústrias e museus. A Usina-Escola Siderúrgica utiliza um sistema de blended learning, agregando assim as vantagens existentes tanto na modalidade do ensino presencial tradicional, como na abordagem do ensino a distância.

Aug 1, 2018

By T. Junne, L. Eltrop, S. Moreno-Leiva, J. Haas, W. Kracht

The energy systems of the future will be highly renewable. The flexibility that is consequently required can be provided with many options, the main ones being energy storage, transmission reinforcement, and demand side management. The role of the latter is explored for the copper industry, using the scheduling of maintenance services as an example of Solar-Paced Design - the coupling of energy demand with solar resource availability. We used a linear energy optimization model to define the minimum-cost configuration for a fully renewable energy system of a copper concentration plant under different scenarios for the scheduling of maintenance services. For the case we studied, (total) costs were 4% lower when the maintenance was scheduled in winter. We expect that exploring the potential of such Solar-Paced Design in the copper industry will allow new potentials for a more cost-effective full renewable energy supply of this critical industry. INTRODUCTION The mitigation of climate change requires a worldwide transformation of the energy system by the significant expansion of renewable energies and the electrification of various sectors and processes (Teske et al., 2015)(International Energy Agency IEA, 2018). Moreover, considering the decreasing costs of renewable energy technologies and the intensive use required to deliver the goals in the Paris Agreement, we can expect to have highly renewable energy systems in the near future. However, to rebuild and expand our energy systems, we need certain materials, including copper. Also, energy systems based on renewables are more copper-intensive than conventional ones (Kleijn, van der Voet, Kramer, van Oers, & van der Giesen, 2011). The mineral industry, in turn, needs clean energy to achieve a better environmental performance (e.g. solar energy for copper production (Moreno-Leiva et al., 2017)) and to avoid negative secondary effects induced by the strong expansion of clean technologies. But there is something else the minerals industry can offer in this bi-directional relation with energy systems.

Jan 1, 2019

By V. Svalbonas

Presently the U.S. mining industry is very conscious of costs. It is timely, therefore, to review the dominant specifications used in the industry for procuring large size-reduction equipment. These are compared with other specifications and procurement methods, such as ASME and DOD, using the criteria of resulting costs, safety/ quality, and fitness-for-service.

Jan 1, 1987

By Palmer C. Sweet

Mining-related wastes, which are increasing, are being utilized more and more as valuable resources in Virginia. The Environmental Protection Agency (EPA) divides mining-related wastes into two categories: those generated from mineral extraction and beneficiation and those generated from mineral processing. Materials from both categories are produced in Virginia, where waste (by-product) materials are present at a variety of mining sites and processing plants; some of which have been exploited for various uses in the past and/or present. These materials include: used concrete recycled for roadbase material; pyrite coated with magnetite for use in portland cement; minor amounts of fly ash for use in concrete block, lightweight aggregate, and flowable structural fills; granite and diabase quarry fines for use as agricultural and asphalt filler; lime kiln dust for use in neutralizing and stabilizing coal refuse; soapstone aggregate for use in terrazzo heat retention panels; kaolin for use as a filler product and as an ingredient in white cement; slate quarry fines used as landcover and combined with aggregate for crusher run and as a filler in asphalt; and coal refuse for use as fuel in a lightweight aggregate plant. There are some materials available that have never been utilized, although several ideas were investigated to turn them into usable commodities. One such material is a high-alumina scrap produced as a by-product at a ferrovanadium processing plant. However, large quantities of waste materials from metal mining, industrial mineral, and fossil fuel operations remain to be disposed of in an environmentally safe and economic manner. In 1989, almost one million tons of fly ash were produced from burning of coal at eight coal-fired power plants in Virginia. Present uses for this waste such as an ingredient in concrete block, concrete aggregate, and in structural fills cannot dispose of all the available material; however, increased use of fly ash as a soil/rock substitute for structural fills and embankments may solve the problem of its disposal. Another waste material is calcium carbonate precipitate paste produced at a lithium carbonate processing plant and presently being used for back filling an on-site inactive underground limestone mine. Flue gas desulfurization (FGD) wastes in the form of CaS04 will probably increase threefold. If this material contains a minimum of 95 percent gypsum and negligible chloride, it may have a value to a wallboard manufacturer as we move toward the year 2000. Thought must be given how this increasing waste can be disposed of in an environmentally safe manner.

Jan 1, 1995

By J. J. Bartels

The phosphate rock review did not arrive in time for publication in the. June issue. The world phosphate industry continued its slide in 1992 from the already depressed levels in 1991. The industry is locked into a 30-year fertilizer price low due to the worldwide fertilizer glut. Domestic production and imported, marketable phosphate rock decreased 1%, while domestic consumption increased by 1 % last year. The US Bureau of Mines reported a decrease in the domestic phosphate rock value from $25.42/t in 1991 to $23/t in 1992 ($23.06/st to $20.80/st). The diammonion phosphate (DAP) product price also dropped in value from $138/ t in January 1992 to $11 0/t in December ($125/st to $99.70/st). Continued declines in DAP prices is forcing the US fertilizer industry to develop cost-saving programs and reorganizations. Layoffs in 1992 resulted in a 7.6% decrease in the Florida phosphate workforce. Since 1980, the Florida workforce has declined by 35%. Small phosphate companies were forced to close operations or were sold to larger phosphate companies. Federal and state environmental regulations for byproduct waste disposal methods are being studied. The Environmental Protection Agency (EPA) approved phosphogypsum use in agri¬cultural and research applications as long as the radium 226 concentration is lower than 10 pci/g. The EPA is also reviewing regulations concerning air emissions at fertilizer plants. Industry publications reported the possibility of continued company sales and mergers in 1993. Industry expectations are optimistic while waiting for an upturn in the market. The US phosphate industry consolidation into three or four major companies should evolve into a stronger world market force.

Jan 1, 1993

By R. W. Henn

Introduction Shotcrete, by the American Concrete Institute definition, is mortar or concrete pneumatically projected at high velocity onto a surface. The term gunite is still common in literature. It is a trade name established by Cement Gun Co. of Allentown, PA, around 1911 for a dry mix of fine aggregate material, hydrated at the nozzle, and pneumatically projected at high velocity onto a surface. This article will discuss shotcrete applications, ingredients, mix proportioning, batching and mixing, admixtures, testing, and steel fiber vs. conventional shotcrete. Applications Shotcrete is used primarily by the mining and underground construction industries to temporarily stabilize an excavated rock surface until a permanent cover can be installed. It may also be used as the permanent covering material. Other uses include refractory material, architectural finishes, slope stability, wearing surfaces, repairing existing concrete structures, fireproofing, and corrosion protection of steel. Wet Versus Dry Process In the wet process, all ingredients, including water but not accelerator, are mixed the same way as normal concrete before its placement by pneumatic projection. The accelerator is added in a liquid state through the nozzle at the point of placement. In the dry process, all ingredients, including acceleration in dry form but not water, are mixed just before placement by pneumatic projection. Water is added through the nozzle at the point of placement. Liquid accelerator may be added at the nozzle in the dry process. Ingredients Shotcrete consists basically of the same ingredients as concrete with some limitations. Type I, II, and III cements are used. However, Type II seems to be used most in underground applications. This can be attributed to ground water at most sites having slight to moderate concentrations of sulfates. Air-entraining cement or air-entraining admixtures are generally not used in dry mix shotcrete. It is generally agreed that it is impossible to entrain air due to the absence of the usual concrete mixing action, and the high velocity of impingement of the material on the application surface. Air-entraining cement or air-entraining admixtures are used in wet mix shotcrete. Their use, however, is not widespread due to the placement method and the fact that high velocity air drives off most of the entrained air. Test results are not conclusive in showing any durability increase of shotcrete to freezing and thawing by using entrained air. In spite of current practice, the trend is toward additional research, with more agencies and owners requiring the use of entrained air. The philosophy behind this is that some entrained air is better than no entrained air to increase durability to freezing and thawing. The aggregates used in shotcrete are the same as those used in concrete. However, the largest coarse aggregate presently used is 19 mm (0.75 in.). A typical gradation requirement is shown in Table 1. The water quality requirement for shotcrete is the same as that for concrete. Accelerators are by far the most important admixture in shotcrete.

Jan 6, 1984

By Fan Yang, Zhiping Wen, Tiancheng Nie, Jinhe Pan, Ruibo Jia, Changchun Zhou

Rare earth elements have important strategic significance and economic value, and the rare earth elements in coal resources have considerable development potential. This study took coal refuse in the Jungar area of Inner Mongolia, China, as the research object, and investigated the occurrence modes of rare earth elements. A special sequential chemical extraction experiment was designed, and the results showed that the rare earth elements in coal refuse mainly occur in silicate and aluminosilicate form, accounting for approximately 65% of the total rare earth elements. According to the results of SEM-EDS, micro morphology of the sample belonged to the lamellar structure of clay minerals, and Al, Si, Fe, S, Y, and La were all present in the sample. Through SPSS software analysis, rare earth elements have an obvious linear positive correlation with Al, Si, and Fe elements, and a negative correlation with S elements. The rare-earth element occurrence mode in coal refuse can provide a definite theoretical basis for the later extraction and enrichment work.

Feb 18, 2022

By R. Wirth, B. Orberger, C. Wagner, A. Tudryn, B. Baptiste, S. Miska, Université Paris-Sud

Banded iron formations (BIFs) comprise complex textures and mineralogy, which result from fluid-rock interactions related to high and low temperature alteration. The initial iron oxy hydroxide mineralogy and associated phases such as carbonates, quartz, apatite and phyllosilicates were transformed leading to an upgrading of these BIFs into the world’s largest source of iron ore. In low-grade BIFs, a large part of the iron is related to micro- and nano- metric iron-bearing inclusions within micrometric quartz and/or carbonates (mainly dolomite). We studied laminated jaspilitic BIF samples from a drill core containing 26.71 wt.% total iron, 0.2 wt.% SiO2, 0.32 wt.% MnO, 15.46 wt.% MgO, 22.32 wt.% CaO, 0.09 wt.% P2O5, < 0.05 wt.% Al2O3, 0.15 wt.% H2O and 34.08 wt.% CO2 (Aguas Claras Mine, Quadrilatero Ferrifero, Brazil). Bright rose coloured dolomite and quartz bands alternate with massive specular hematite bands. Raman spectroscopy, X-ray diffraction and FIB-TEM analyses reveal that the micro- and nanometric inclusions in dolomite are mainly hematite and minor goethite, partly occurring as clusters in voids. Curie Balance analyses were carried out at different heating steps and temperatures on whole rock samples and a synthetic mix of decarbonated sample and pure dolomite. X-ray diffraction on the products of the heating experiments shows that that hematite is stable and new phases: magnesioferrite (MgFe2O4), lime (CaO), periclase (MgO), portlandite (Ca(OH)2) and srebrodoskite (Ca2Fe2O5) were formed between 680°C and 920°C. These finding gives hints to optimizing the beneficiation process, as the presence of hydroxyl ions bearing goethite micro- and nanoinclusions lowers the sintering temperature. Prior separation of coarse hematite and barren dolomite and quartz, followed by lower temperature sintering of the inclusionbearing dolomite/quartz leads to transformations into phases with higher magnetic susceptibilities (such as hematite and magnesioferrite). The entire Fe and Fe/Mg oxide feed (the priorly separated fraction added to the sintered fraction) can then pass through wet-high intensity magnetic separation after crushing.

Jan 1, 2016

By Junnan Chen, Hongwei Zhang, Wei Wang, Feng Xie

Thiosulfate is a green gold leaching agent that shows great potential to replace the highly toxic cyanide. Ammonia is traditionally used as the copper ligand in thiosulfate solutions to reduce the reactivity of copper ions towards thiosulfate, but it is a toxic reagent. As a result, efforts to replace ammonia with another complexing agent have received increasing attention. In this study, a novel alternative to ammonia is proposed to explore the potential use of the copper-malic acid-thiosulfate system. Experimental parameters include temperature, initial pH, copper, malic acid, and thiosulfate concentration. The feasibility of the copper-malic acid-thiosulfate system was discussed using Eh–pH and species distribution diagrams. Themodynamics analysis indicates that the mechanism of gold leaching in copper-malic acid-thiosulfate solution is mainly catalyzed by the Cu2( Mal)2H-2 2−/Cu(S2O3)3 5− redox couple. The capability of gold leaching in this system for processing the refractory gold concentrate is comparable to that of cyanidation and the traditional copper-ammonia-thiosulfate leaching processes. Thiosulfate consumption is greatly reduced in the presence of malate due to its strong chelating effect on the copper ions. Moreover, the copper-malic acid-thiosulfate system demonstrates a significant enhancement in leaching kinetics, making it a viable option for processing refractory gold concentrates.

Aug 1, 2023

By Howard Eavenson

SOME time ago, in a conference considering the mechanizing of a group of mines, I was asked if I knew of any data showing the relative frequency of accidents due to the use of 275 or 550-volt current inside mines and having a recollection of seeing some in print, the answer was made that I would find what was available. Subsequent search failed to find any pub-lished records of any kind giving such figures and none of the compensation agencies of whom inquiry was made were able to supply any, excepting the Pennsyl-vania Compensation Rating and Inspection Bureau, which had some data covering a few months for some companies in that State. The inquiry was confined to the three largest producing States, Pennsylvania, West Virginia, and Illinois. The inspection departments of neither of the first two had any such records, and in Illinois, only 275 volts has been allowed inside the mines for many years. A laborious inquiry has resulted in the data, shown in Table 1, which on this account was confined to the years 1921 and 1925, the latter being the latest figures available. In each State, to find the mines using 275 and 550-volt current respectively, it was necessary to list the mines from the Coal Catalog, and then to complete the list by inquiries from the companies directly, from Operators&apos; Associations and from Inspection Depart-ments. As the mines not electrified, and those using

Jan 5, 1928

By Harry Perry

In the United States the state mining laws enacted in the late 1800s were the first laws to recognize that an employer had a responsibility to provide the employee a place to work that met at least some minimum safety standards. The coal mining industry was also the first major industry in the United States to be regulated in 1952 by federal safety laws, although federal inspectors had the right-of-entry as early as 1941. Within recent years, however, the Congress has enacted a number of federal safety regulations for a variety of industries, such as the Aviation Act (1958), National Traffic and Motor Vehicle Act (1966), National Gas Pipeline Act (1968), and Radiation Control for Health and Safety Act (1968). The fatality and injury experiences of the mining industry in the United States, while at a significantly higher rate than for industry as a whole, showed a continuous improvement until the last decade or two-at which time the rate leveled off. Although fatality and injury rates in foreign countries have been generally lower than in the United States, further improvement in those countries also has been difficult to achieve in recent years. It appears, therefore, that some major change in mining laws, combined with a radical improvement in mining technology and a more effective labor-management safety program, will be needed if further reductions are to be achieved in fatality and injury rates. At the same time, there is a growing awareness by society that an employee&apos;s place of work, where he spends nearly half of his waking hours, should be made as safe as possible. As increased consideration is given to means for achieving greater safety in all industrial situations, it is becoming apparent that more is required than merely providing physical safeguards on tools and machines. Rigorous, strictly enforced safety standards are useful, but more important is the desire of labor and management to make certain that industrial accidents are prevented. The pressure to achieve increased productivity, and thus receive higher wages, can be a significant deterrent to safe working practices. The temptation can be great to "take a chance" or "cut a corner" in order to speed up production. Public concern over all types of industrial safety in the United States was reflected by the introduction of a number of general occupational health and safety bills in Congress for the first time in 1968. While no legislation resulted, the hearings revealed that, although there were differences in how standards should be set and who should administer them, there was agreement on the need for adequate laws. Since the mining industry has been subject to safety standards longer than other industries, it is not surprising that advanced safety concepts for mining are being explored by the industry and the enforcing agencies. More complete and sophisticated accident reporting is being planned that will reveal the

Jan 1, 1976

By E. E. Bach

The administration of industrial organization today embraces more than the cost of production and selling prices. Competition is deeper seated than mechanical devices, overhead charges, and a shrewd manipulation of the markets. Despite the " down-to-the-minute " equipment and the "last word in organization," it is quite evident that "capacity production" will be an unknown quantity until the workman is considered as a producer, in relation to his home, as he is now considered in relation to industry. Whether or not a man shall do an honest day&apos;s work is as much a psychological condition as it is a matter of physical strength or skill. His attitude toward his work each morning is determined, to a large degree, by the environment of his home. Whether this attitude, good or bad, obtains the day through will depend entirely upon the one fact as to whether the corporation which employs him does or does not differentiate between the mechanical factor and the human factor in industry. To be more specific, sociological work, under whatever name, should be of such a character as to influence the life of a workman in such a manner as to establish a cooperative interest in his work, foster within him a spirit of contentment in his home, lead him so to employ his leisure time that he will not lower his efficiency as a workman, destroy his domestic happiness, or endanger his standing in the community as a citizen. While no fixed rules of procedure can well be formulated for the development of the work, yet definite lines of activities will readily present themselves as applicable to the individual needs of a community. This is especially true where community influences and agencies pertaining to general welfare are easily correlated. Any definite work attempted must be determined by the type of the

Jan 1, 1918

By Ximeng Li

The entries that are subjected to dynamic pressure are much more difficult to maintain due to repeated disturbance. A case study of an entry stress distribution was performed using the FLAC3D program. By analyzing the distribution of stress field around the entries, this paper provides guidelines for entry support design in the lower (#16) seam subjected to the repeated disturbance from longwall mining in the immediate overlying (#17) seam, 72ft (22 m) above. The results showed that there was stress superposition inside the barrier pillar in the lower seam, 15ft (5m) to 45ft (15m) deep, during development. The influence zone of the front abutment pressure in the upper (#16) seam was about 100ft (30m) outby the faceline. The stress-relieved zone was from 0 to 100ft (30m) inby the face. The area further inby the face (i.e., 230 ft (70 m) inby the face) was within the gob compaction zone. Along the face advancing direction, the affected zones of the entries in the lower (#17) seam that were subjected to the dynamic pressure from longwall mining of the immediate overlying seam could be divided into four stages: pillar development stress stage, front abutment pressure stage, unstable gob stage, and stable gob stage. Those entries within an area from 100ft (30m) outby to 100ft (30m) to 230ft (70m) inby the faceline should be reinforced with special supports. The numerical modelling matched the monitoring results well.

Jan 1, 2013

By Charles W. Daugherty, Eugene B. Waggoner

In the construction of recent subsurface projects, particularly mined openings and transit systems, it has been apparent that final costs were often greater than first expected. Because many overruns result from alleged differing site conditions, there was reason to suspect that pre-bid geotechnical investigations were inadequate for predicting subsurface geology. In 1982, nine federal agencies involved in constructing underground facilities funded the National Academy of Sciences&apos; U.S. National Committee on Tunneling Technology (USNC/TT) in an effort to evaluate and clarify the relationship between geological knowledge and construction costs. That committee formed the special Subcommittee on Geological Site Investigations, which spent more than two years studying underground projects by examining contract documents and geologic reports, making site visits, and interviewing owners, designers and contractors. The study ultimately encompassed 84 mined tunnels and chambers and three deep shafts in the United States and eastern Canada. Data collected on geologic exploration, design and construction were analyzed and conclusions reached concerning whether and how site investigations need to be improved. The results of the study are published in two volumes by the National Academy of Sciences. Due to the recent completion date of the main report, it was not possible to prepare a summary for inclusion in the RETC Proceedings. However, the complete two-volume report, "Geotechnical Site Investigations for Underground Projects," can be obtained by writing or calling: U.S. National Committee on Tunneling Technology National Academy of Sciences 2101 Constitution Avenue, N.W. Washington, D.C. 20418 (202) 334-3136

Jan 1, 1985

US Tin Mission To Study Costs in Far East A move to obtain adequate supplies of tin at prices the United States is willing to pay was initiated when the interagency tin mission left for the Far East. The Mission, which includes representatives of the Reconstruction Finance Corporation, State Department, Defense Minerals Procurement Agency and the Bureau of Mines will go to Indonesia and Malaya. The primary purpose of the mission, according to officials, will be to study tin production costs, not to negotiate for the purchase of tin. The mission will be prepared to enter into negotiations, if the Far Eastern producers are amenable. The United States withdrew as a large-scale buyer of tin some months ago in protest against what it considered exorbitant prices being charged in the Singapore market. Subsequent attempts to negotiate for a steady tin supply at what this country considers reasonable prices have been unavailing. The U. S. is prepared to enter into a two or three year contract with the price of tin somewhere between $1.00 to $1.12 per lb. The decision to abstain from the market has not yet put a squeeze on U. S. supplies. Substantial quantities of tin still are coming in from Malaya under an old contract.

Jan 12, 1951

The Mineral Research Centre is located at Perth in the suburb of Waterford, adjacent to Curtin University of Technology and within a Technology Precinct which includes Technology Park. The Centre, constructed by the WA Government at a cost of $16 million and occupied in late-1994, comprises three separate buildings housing the CSIRO Division of Minerals, Curtin University&apos;s School of Chemical Engineering and the Mineral Processing Laboratory of the Department of Minerals and Energy. The emphasis on R&D at the Centre is primarily in hydrometallurgy as a result of staff expertise, extensive bench and pilot-scale facilities, track record with the industry and, very importantly, two of the occupiers being partners in the AJ Parker Cooperative Research Centre for Hydrometallurgy. Staff in the Centre have a long involvement with R&D agencies such as AMIRA and MERIWA. The hydrometallurgical focus of the Centre complements that of pyrometallurgy at the GK Williams CRC in Melbourne and the Centre for Mining Technology and Equipment in Brisbane, to ensure that the mineral processing industry in Australia has access to a complete range of expertise and facilities to serve its needs.

Jan 1, 1996

Discussion of the paper of M. B. YUNG, presented at the Pittsburgh meeting; October, 1914, and printed in Bulletin No. 93, September, 1914, pp. 2451 to 2458. T. T. READ, New York, N. Y.-I might .point out that this paper of Mr. Yung&apos;s is on a field that is comparatively little known. It is not as well known as the Kochiu tin field, of Yunnan, which is probably the third . in tin output of the world. This field under discussion is considerably further west and the tin which is produced here is, according to Mr. Yung, of somewhat higher grade than the Yunnan tin, and is used by the refiners at Hong Kong to improve the grade of the Yunnan tin. Most of you know that the tin from the Yunnan is shipped to Hong Kong, where it is refined and shipped to Europe. Mr. Yung points out that the Fu Chuan deposits are entirely alluvial and not found in any veins. They .differ in that from the Kochiu deposits, which Leclere says are "nullement alluvionels; leur origéne filonienne est de plus evidentes." Granite is the country rock here; doubtless the tin occurred in veins in the granite, and the deposits have resulted from the disintegration of the granite. This is a country of strong erosive agencies. The country is semi-tropical, and the rainfall is heavy, so that one would naturally expect deep surface erosion of this kind.

Jan 4, 1915

By Philip U. Santacroce, James H. Meinholz

INTRODUCTION The Milwaukee Metropolitan Sewerage District (MMSD), is a special purpose sub-regional agency that provides collection and treatment services for sanitary wastewater for an area of 420 square miles (1088 km2) in 27 municipalities in the Milwaukee, Wisconsin metropolitan area. During its almost 75 years of existence, it has constructed 464 km of intercepting sewers, the majority in tunnel, and two sub-regional secondary wastewater treatment plants. The present program, the $1.7 billion Milwaukee Water Pollution Abatement Program, was started in 1977 and developed from ongoing internal planning, the Federal Clean Water Act and court judgments. Elements of the Program include improvement and expansion of the two treatment plants; rehabilitation of older in-place sewers; building new interceptors and relief sewers and providing capacity for high volume storage in approximately 32 km of deep, large diameter rock tunnels; reducing combined sewer overflow; and disposal/utilization of the solids that remain after the treatment process. The construction phase of the Program accounts for $1,105,900,000 within 335 separate construction contracts, 211 let to date, and covers a span of 15 years, starting in 1979 and running through 1994. Conveyance System construction cost is estimated to be $650,000,000 or about 60 percent of the total. Through December 1986, in terms of dollars, the total construction program is about 38 percent complete with Conveyance at 34 percent complete.

Jan 1, 1987

By Terry Owen

Not since 1917 has a foreign company developed a standalone, grass roots gold mine in Russia. With Russia&apos;s political changes of the late 1980s, development of mineral prospects once again beckons foreign investors. Cyprus Amax&apos;s interest in Russia began before the mid-1991 breakup of the former Soviet Union. In 1990, Cyprus Amax began searching for such an opportunity. Early this year, production will begin at the Kubaka gold project located in the Russian Far East, near the Arctic Circle. The Kubaka project is a 1.75-kt/d (1,930-stpd) open-pit operation that will produce more than 9.3 t/a (300,000 oz/year) of gold. Identifying Russian mining opportunities In late 1990, the first Cyprus Amax people travelled to Russia. The trip was to determine the potential for western firms to develop profitable mines. This encouraging visit suggested that Cyprus Amax focus on the Russian Far East with its mineral riches and its easier access to the United States. The company&apos;s initial efforts thus focused on working with the Soviet Union&apos;s Northeast Geologic Expedition, the then government agency for exploration and geology in Russia&apos;s Far East. After the breakup of the Soviet Union, Cyprus Amax continued working with the same people, but they now represented new independent, nongovernmental entities. For three years, Cyprus Amax investigated numerous deposits. This resulted in the identification of two properties of significant interest, one of which was Kubaka. Location Kubaka is located in the Northern Evensk District of the Magadan Oblast in the Russian Far East. This is an area east of Siberia. The project is situated in a mountainous area of the Kolyma Range, about 300 km (985 miles) south of the Arctic Circle. It is 285 km (180 miles) north of the fishing village of Evensk and 380 km (235 miles) northeast of the silver-mining town Omsukchan. The site is 950 km (590 miles) northeast of the regional capital city of Magadan. Magadan, the political and economic center of the Oblast, has a population of about 150,000 people. It is served by a year-round deep-water port (with icebreaker assist) and an international airport with service to Moscow and Anchorage, AK. Access to the Magadan region

Jan 1, 1997