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By Ladislav Bebar, Tomas Parizek, Radek Dvorak, Petr Stehlik

"More and more sweeping environmental regulations initiate research, development and introducing into operation up to date technologies for cleaning off-gas and flue gas generated in various branches of industry and municipal waste treatment. The following systems based on novel types of equipment are shown: thermal and catalytic treatment of waste gases polluted by VOC (Volatile organic compounds) and carbon monoxide (alternatively NOx), catalytic filtration for efficient destruction of PCDD/F (dioxins) and potentially NOx, wet cleaning of flue gases polluted by SO2, HCl and HF with a original type of homogenizer “O-element”, integrated equipment for cleaning waste gases polluted by solid particulates, SO2, HCl, HF and heavy metals (alternatively NOx or PCDD/F). The outstanding features of all equipment mentioned above are low investment and operating costs together with high removing efficiency of pollutants. These units can be used mainly in incineration plants, refineries and other chemical plants. The paper represents a review based on papers published in reputable international journals and a monograph under preparation as well as on experience from industrial applications.IntroductionIn the recent years, more and more emphasis is put on preserving clean environment. One of the most closely monitored objects of general public attention are exhaust gases, containing a number of undesirable compounds like NOx, CO, SO2, HCl, HF, fly ash a PCDD/F. These harmful species are created in chemical processes mainly in the industry, transport and energy sectors. There is therefore a strong impetus for abatement of these harmful pollutants. Sectors of industry are thus subject to emission regulations specific to various types of units. In the framework of increasing demand for a clean environment, the concerned legislation is becoming increasingly strict and requires removal of pollutants by modern methods that would ensure efficient abatement of emissions at reasonable investment and operating costs.Attention is focused chiefly on methods for decreasing harmful emissions from thermal waste treatment facilities processing industrial and municipal waste that may be subsequently applied in other sectors of industry. Units for the thermal treatment of waste not only provide means of its disposal, but may become also important sources of energy, provided that strict emissions limits are satisfied. Figure 1 compares emission limits given by the legislation for municipal waste incinerators and limits for a selection of energy sources with heat capacity up to 50 MW (see EU regulation 200/76/EC). The Figure implies that the values of emission limits for waste incineration are mostly comparable with emissions from the combustion of natural gas. Thanks to the continuing improvements of the methods for removal of harmful pollutants, the emissions from waste incinerators are typically deep below the limits."

Jan 1, 2008

By Robert B. Parsons

"Ontario and Quebec taxpayers will have to dig deeper into their pockets to pay more tax, according to budget papers tabled in these provinces in May 1993. Individuals will be hardest hit, but corporations will also have to ante up in the face of higher rates, reduced deductions, and new taxes.Up, up, and away...Somewhere in the bleak picture of the 1993 Quebec and Ontario budgets, there is a bit of good news for the mining industry.Careful scrutiny reveals:• Ontario will correct a capital tax provision which inadvertently penalizes flow through share issuers;• Quebec's flow-through incentives will be extended to December 31, 1995; and • both Quebec and Ontario will allow deductions for mine site reclamation payments.The industry may also find some comfort in the fact that Ontario's new corporate minimum tax will be profit-based (unlike the federal minimum tax), so that non-producers should not face a liability for this tax. There is some concern though, about Quebec's announcement that the refundable credit mechanism in the Mining Duties Act will be reviewed."

Jan 1, 1993

By Irwin R. Higgins

CONTENTS A. Introduction B. System Description C. Uranium Pilot Plant Programs D. Summary INTRODUCTION The Chem-Seps Continuous Countercurrent Ion Exchange (CCIX) contactor was first conceived of in 1951 at the Oak Ridge National Laboratory. In the 27 years that have passed, there has been a steady stream of pilot plant process development studies on a variety of processes far too numerous to mention. These have been in the area of water and waste treatment, chemical processing, ore leach treatment, and many others. Many successful production systems have been installed and operated in a variety of applications. A few of these are described herein together with a description of the system and its operational characteristics. SYSTEM DESCRIPTION Chem-Seps Continuous Countercurrent Ion Exchange* is a single loop in which various sections are separated by valves to isolate the sections performing different functions simultaneously. (Refer to Figure 1). To explain the working of a typical unit, let us use a simple configuration used in water softening or demineralization. The resin is moved in small increments by the hydraulic ram action. All solution flows are countercurrent to the flow of resin. The contaminants are removed in the process cycle and the resin is moved in the pulse cycle. A controller in the effluent stream from the treatment section senses the proper limit permissible in the effluent. In the process cycle, the influent enters through a set of distributors, moves downward and leaves through a set of collectors. Simultaneously the regenerant enters through valve RE and leaves through valve WA. The rinse enters through valve RI and its duration is controlled by an interface controller. In the process cycle, valves B, C, and D are closed, isolating all the sections. The duration of the process cycle is 4-10 minutes depending on the contaminants to be removed and is controlled either by a timer if the contaminants are fixed, or a controller in the effluent stream, if the contaminants fluctuate at short intervals. Valve A is open and resin is dropped to the pulse section simultaneously with the removal of contaminants in the treatment section, regeneration of loaded resin in the strip section, and rinsing of regenerated resin in the rinse section. As the resin drops through the valve A, it is backwashed to remove the suspended solids or resin fines. Removal of these fine particles is important to avoid the unnecessary pressure drop in the bed and plugging of the distributors. At the end of process cycle, all flows going into the unit and out of unit are automatically shut off. The valve A closes and valves B, C, and D open in proper sequence. A slug of water enters through valve PU, a predetermined incremental volume of resin moves into the regeneration section, an equal volume of regenerated and rinsed resin enters the bottom of the treatment section, and an equal volume of the loaded resin leaves the top of the treatment section and goes into the resin reservoir section. (The resin movement is plug flow with the Reynold's number being in the laminar region of the curve, and no fluidization occurs during the pulse cycle.) The total time required for proper sequencing of valves and the movement of resin is 20-30 seconds. At the end of this period, the valves B, C, and D close and valve A opens. The solution valves open and normal steady state operation begins. All valves are interlocked and properly sequenced. The resin movement is precisely controlled by sonic devices. Special Features of Chem-Seps CIIX "Downflow"*: The raw feed in the treatment section moves downward and the resin moves upward in the treatment section. The "downflow" of feed overcomes the handicap encountered in "upflow" systems. The "upflow" of feed requires a certain minimum flux during process cycle to lift the bed and keep it

Jan 1, 1979

By Nathan A. Ingraffea

The use of steel sheet pile walls and drilled shaft foundation elements to enable up-down construction methods has been used successfully on recent high-rise structures with multi-story below grade parking. The John Ross Tower and The 3720 Tower in Portland, Oregon each make use of this system and are discussed in-depth. Up-Down construction involves the simultaneous construction of the building levels above and below grade instead of the standard construction technique of excavating and shoring the below grade construction before being able to build upward from the base of the excavation. Advantages of the up-down system include a shortened overall construction schedule, permanent basement walls that double as the temporary shoring walls, elimination of the typical continuous wall footing or grade beam at the building perimeter, increased use of recycled material (steel) while maintaining an overall decrease in total materials, elimination of wall forming costs, decreases in forming costs for slabs, decreases in waterproofing costs for walls and elimination of pile caps and/or footings for the building columns. Lessons learned during the construction of both buildings include the need for more extensive geotechnical boring information, descriptive sheet pile and drilled shaft specifications, a clear understanding from the design team on finished appearance of sheet pile and shafts, and careful consideration of the connection between both slabs and the sheet pile wall and slabs and drilled shafts.

Jan 1, 2008

By Adams F. C, Ridley K. L

Economic conditions after WorId War II made the recovery of Australian sources of sulphur one of considerable national importance. From 1947 to 1949 an investigation was made of recirculation techniques to produce acid plant grade gas from the Dwight-Lloyd down-draught sintering plant.During 1949 it appeared feasible to produce a gas of suitable 802 concentration and a decision was made to construct a gas purification train and a 150 tons/day contact acid plant. However, a number of difficulties remained in the production of the gases for sulphuric acid manufacture and as a result of research conducted to overcome these troubles the continuous up-draught sintering process was developed.The principal difficulties were:(a:) The down-draught sintering practice, as developed, produced an unusually high metallic lead precipitation in the windboxes. The disposal of this lead interrupted sintering operations and the delivery of gas to the acid plant.(b) The production capacity of the existing sintering plant was fully extended and the adoption of recirculation of gases, in an endeavour to satisfy acid plant requirements, would probably reduce the plant production capacity.(c) The prevailing high temperature of water available for purification train cooling required a higher than...

Jan 1, 1956

By Georgios Kalamaras, Chiaia Dinu, Platania Paolo, Alessio Carlo, Giampiero Cirvegna, Claudio Santucci

The Project alignment initiates north of Pinerolo, along the State Road 23[S.S. 23] that is one of the principal arteries to the northwestern Alps where a number of Olympic events for the 2006 Winter Games will be held. The 3.5 km ring road bypasses the Porte habitat by traversing twice the Chisone River. It consists of the following principal structures [Figure 1]: San Martino bridge [130 m in four bays] Prarostino viaduct [130 m in four bays] Craviale tunnel [1055 m] Turinella bridge [a 50 m long bridge that connects the two tunnels] Turina tunnel [665 m] Malanaggio viaduct [350 m in 9 bays]. The road section is 13 m wide and is made up of two 3.75 m lanes, a hard shoulder [1.50 m wide] and a 1.25 m wide curb for each lane. The Project maximum velocity is 100 km/h.

Jan 1, 2005

By A. Mejias, M. A. Garcia, G. Diaz

During 1997 and 1998 two successful zinc feasibility studies, Skorpion and Sanyati, were carried out by Tecnicas Reunidas based on the modified ZINCEX® technology. The technical viability of each project was proved during more than 600 h of continuous running in a pilot plant. The Skorpion zinc project would recover 150,000 t SHG Zn/y from an oxidized zinc ore of a Namibian mine. The economical study showed that the plant would have the lowest production costs in the world. The Sanyati zinc project would treat a bleed from an existing copper refinery in Zimbabwe to recover 5,000 t SHG Zn/y. In the first case the electrowinning cellhouse was supplied by Union Miniere and in the second by Tecnicas Reunidas. This article highlights the pilot plant results and the advantages of the proposed process over conventional zinc production practices.

Jan 1, 2000

By D. R. Maneval

The Surface Mining Act of 1977 required a study by the National Academy of Sciences regarding the special mine reclamation requirements of Alaska. The status of mines operating and planned in Alaska will be presented. New mines opening in Alaska must establish a baseline inventory of plants and animals in the mine site area as well as determine pre-mining air and water quality. Current work in these areas will be summarized. Reclamation practices in Alaska and other Arctic countries as practiced currently will be described. A summary of current research in Alaska dealing with revegetation on surface mined lanais, re-establishment of animal populations, and water treatment processes necessary in this pristine environment will be discussed. Included will be future predictions of the direction of mine reclamation in Alaska as more mines enter the industry.

Jan 1, 1984

By L. M. Bigler, J. L. Dobra

With the passage of Mexico's Mining Law in 1992, the tax treaty with the US in the same year, and the passage of the North American Free Trade Agreement, gold mining for non-Mexican mining companies in Mexico has changed dramatically. The statutory changes have created an opportunity for non-Mexican precious metals' producers to own 100% of a Mexican gold concession. This paper examines the financial feasibility of a hypothetical gold mine and processing plant in Mexico. The analysis includes the operational consequences of the recent weakness of the peso, as well as tax and employment issues.

Jan 1, 1996

By Charles L. Kimbell

World political events that occurred subsequent to yearend 1989 but that bear heavily on the global mineral industry have been of such significance that they cannot be disregarded, and certainly they contribute to any type of "outlook?. However, to write of them simply as "forecasts" in an "outlook" section of this study would be to unjustly pretend to status as prophets. Thus, this section covers events that have occurred not as predictions but rather as history. The section also includes an element with some broad statistical information, but this is included last rather than first for two reasons: the information is subject to considerable re- vision as additional data become available and as preliminary returns are corrected; and the authors view it as less important than the events that govern the statistics. The Near East and the Crisis There.- Of all 1990 political events influencing the world's mineral industry, the Iraqi invasion of Kuwait and the remarkable events that followed this aggression must head the list. The almost immediate imposition of economic sanctions, involving embargoes on shipment of virtually all goods into and out of Iraq, caused severe dislocations in the production and trade of mineral commodities, not only within the region itself, but with a ripple effect, into other world areas as well.

Jan 1, 1992

By Charles L. Kimbell

World political events that occurred subsequent to yearend 1990, but that bear heavily on the global mineral industry, have been of such importance that they cannot be disregaded, and certainly they contribute to any type of "outlook." However, to write of them simply as "forecasts" in an "outlook" section of this study would be to unjustly pretend to status as prophets. Thus, this section covers events that have occurred not as predictions but rather as history. Despite the end of the cold war, the world remained fractionated, at least from the limited perspective of its mineral industry. The fractionation was not so much the result of adversarial politics between countries and groups of countries, although to be sure, such conflicts had not disappeared. Rather, the fractionation was in the widely divergent patterns of performance that resulted from the diverse conditions and problems facing the different countries and country groups.

Jan 1, 1993

By Charles L. Kimbell

While the statistical summary focuses on 1991 data, this update and outlook section draws on information available to the author as of the date of final preparation in early 1993. For all the press notoriety associated with the shift in the Near East crisis from the defensive posture of Desert Shield to the restoration of Kuwaiti sovereignty through Desert Storm, this was not the dominant event governing global economic thinking in 1991 and the first half and more of 1992. From the global perspective, the momentous political changes in the area that was the U.S.S.R. and in the smaller emerging transitional economy states of Eastern Europe will have even greater current and long-lasting effects on world mineral industry activities than the crisis in the Near East.

Jan 1, 1993

This work shall consist of furnishing and driving foundation piles of the type and dimensions designated on the plans or in the special provisions including cutting off or building up foundation piles when required. This specification also covers providing test piles and performing loading tests. Piling shall conform to and be installed in accordance with these specifications, and at the location, and to the elevation, penetration and bearing capacity shown on the plans or as directed by the Engineer. Except when test piles are required, the Contractor shall furnish the piles in accordance with the dimensions shown on the plans or special provisions. When test piles are required, the pile lengths shown on the plans are for estimating purposes only and the actual lengths to be furnished for production piles will be determined by the Engineer after the test piles have been driven. The lengths given in the Engineer's order list will include only the lengths anticipated for use in the completed structure. The Contractor shall, with-out added compensation, increase the lengths shown or ordered to provide for fresh heading and for such additional length as may be necessary to suit his method of operation.

Jan 1, 1989

By Janice Zinck, Maziar E. Sauber

"To counter the recent uncertainty in the rare earths market, diversify the supply source, and help meet the future demand in this sector Canada initiated development of several new rare earth deposits. In the past few years, a number of various studies on rare earths plant design have taken place mainly covering process development, process selection, and flowsheet design. The purpose of this paper is to provide an overview of known domestic and potential resources and reserves of rare earths and their status quo with a focus on the metallurgical processes using the information available in the public domain. Plant designs currently under consideration in Canada are reviewed and evaluated. An outline of the areas of opportunity for selective innovation and technology development in the rare earths flowsheet development and the associated risks and rewards is provided.INTRODUCTIONThe rare earth elements (REE) have a very small annual market, but they are categorized as very strategic metals vital to global economic growth due to their indispensability to the development of modern defence system, green technologies and electronic applications. The International Union of Applied and Pure Chemistry (IUPAC) defines the REE as the 15 elements on the lanthanide series on periodic table of elements, plus yttrium and scandium. REE are classified as light rare earth elements (LREE; La to Gd), and heavy rare earth elements (HREE; Tb to Lu). Physical properties and chemical reactivity of yttrium is similar to those of HREE, thus it is categorized as such. Properties of scandium are not similar enough to classify it as either a LREE or HREE (Weng et al., 2015; Sappin & Beaudoin, 2015). However, the mining industry does not always abide to this definitive classification of the split between LREE and HREE. Therefore, in a comparative study of projects, there is a need to pay attention to how the elements are classified."

Jan 1, 2016

By C. Cornejo, C. Schuffeneger, J. Rosas

"At the end of 2010 the AMSA Esperanza Concentrator started commissioning. Located in the Atacama Desert this project is the first of several large size concentrators developed recently to operate in Northern Chile. In addition to the new operations to be implemented in the short term, many existing installations are planning expansions. The use of large size equipment is one of the common characteristics of the new concentrators, but also new technologies are being considered and innovation is present in most cases. Sea water or desalinated water will be required to process large tonnages of sulphide copper ores as well as gold bearing ores, since process water supply from the Andes will no longer be available. The high cost of sea water or desalinated water supply and the high cost of energy are not a limitation as the current metal market scenario allows obtaining an attractive NPV even from installations designed to process relatively low grade ores. A review of the current concentrators being developed in Chile is presented, including a description of the main design issues related to technology and innovation. An analysis of the Chilean mining industry is also presented, detailing mine and plant capacities as well as expected final products.INTRODUCTION The mining sector in Chile has become a reference when analysing the large concentrator plants projected or currently in operation all over the world. At present and as a consequence of the high price of metal commodities, most South American countries have an active mining sector. Chile is known as a major producer of metals. First records of copper production exported to Spain are dated to the early XVII century. Since then Chile has produced over 13% of the total copper ever produced in the world. After 1990 Chilean mining and the associated cluster of activities has substantially grown to levels never reached before, especially in the production of copper, gold and other non-metallic minerals. This dramatic increase is the result of an economic policy based on delivering comparative advantages and incentives for the admission of foreign capital to offset the weak domestic investment in previous decades. Massive mining of its huge mineral resources has allowed Chile to be a world leader in the production of copper and other base metals and mineral products."

Jan 1, 2012

By J. N. Van der Merwe

Following the Coalbrook disaster in 1960, research into coal pillar strength resulted in the adoption of the concept of a safety factor for the design of stable pillars in South African coal mining. At the time when the original statistical analysis was performed by Salamon and Munro in the early 1960s, 27 cases of failed pillar workings were considered suitable for inclusion in the database of failed pillars. Pillar failure did not stop after the introduction of the safety factor formula by Salamon and Munro (1967). In the ensuing years, pillars that were created before the application of the formula deteriorated and later failed, as did ones that were created after the introduction of the formula. This means that over time, the database of failed pillar cases increased in size, allowing ever more reliable analyses to be performed. The number of failed cases in the database had grown from the original 27 in the 1960s to 86 by 2011. All the failed cases are contained in the updated database. The database of stable pillars, which is also used in the derivation of strength formulae, has now been extended from 125 to 337 cases. The new database of intact pillar cases is more complete as it bridges the time gap between the Salamon and Munro (1967) and the Van der Merwe (2006) databases. The original requirements for inclusion into the database were satisfied in the compilation of this latest collection. The characteristics of the original database of intact pillars did not change in a meaningful way. The mining depth and pillar dimensions of the new database are largely as they were in the original database. Time-related trends with regard to pillar dimensions and depth of mining could not be found, indicating that the geometrical parameters of coal mining in South Africa have not changed meaningfully in approximately a century of mining. The characteristics of cases in the updated database of failed pillars does not differ substantially from the one published by Van der Merwe (2006). The same difference between that database and the original Salamon and Munro database, namely that the average safety factor of the failed cases had increased dramatically, from 1.0 to 1.5, is still apparent. This may be due to the inclusion of more failures from specific areas that exhibit a disproportionate number of failures at higher safety factors. These areas are the Vaal Basin, Klip River, and Free State coalfields. The new database confirms yet again that there is no correlation between the safety factors of failed pillars and their time of failure. The safety factor on its own is thus not a reliable predictor of longterm stability of pillars. Keywords coal pillar, stable pillar cases, pillar collapse, pillar data base.

Nov 1, 2013

By Chris Joyce, Peter Ryan, Graeme Mcllveen

This paper briefly summarizes regulatory procedures and government agency roles and jurisdictions in each Australian State and Territory. The role of the Commonwealth of Australia and selected current trends in environmental regulation are also discussed. While the Commonwealth has played an active role in regulating specific commodities or mines through its powers over export licences, international heritage agreements and the Territories, such cases have largely been a result of response to specific public issues. This may change; the Commonwealth has established the Resources Assessment Commission and is canvassing the establishment of an Environmental Protection Act, aimed at the standardization of environmental standards through the creation of an Environmental Protection Authority. While the States, the Northern Territory and the Commonwealth lwve nominally different resource planning, environmental project approval and operational regulatory authoritit:s, the fundamental principles hinge on mining lease, planning and pollution control approvals.

Jan 1, 1991

By V. T. McLemore

"Production of industrial minerals remains important to the rural economy of New Mexico. In 2014, some 240 mines were registered in New Mexico, including 25 industrial mineral operations and 189 aggregate operations. New Mexico leads domestic production of potash, perlite, zeolite, and travertine. Other production includes aggregate, humate, pumice, gypsum, salt, common and fire clay, scoria, limestone, fly ash, cement, magnetite, silica, and decorative stone. New Mexico has potential for additional production of industrial minerals. One company is exploring for garnet. Cretaceous black sandstones in the San Juan Basin have drawn interest for titanium, rare earth elements (REE), and zircon. Other REE deposits are being explored. REE-Th-U veins are found in the Gallinas, Capitan, and Cornudas Mountains and Laughlin Peak-Chico Hills. Recent exploration has occurred for beryllium in the San Mateo Mountains, Iron Mountain, and Victorio districts. Companies also are examining High-Ca limestone and High-Mg dolomite for potential development. Aggregate continues to be important in urban areas and along highways. INTRODUCTION Industrial minerals and rocks are literally the building blocks of our way of life and they are an exceptionally diverse and vital group of raw materials that underpin almost all aspects of human activity, infrastructure, and standard of living. Industrial minerals and rocks are used in the manufacture of many products, from ceramics to plastics and refractories to paper. Although industrial minerals permeate every aspect of daily life, their presence and their role are typically invisible. A widely used definition of industrial minerals and rocks is “any rock, mineral, or other naturally occurring substance of economic value, exclusive of metal ores, mineral fuels, and gemstones: one of the non-metallics” (Bates, 1975). This definition includes the important construction materials sector as well as specialized industrial minerals, but complex interactions between consumer industries produce a number of apparent anomalies to this definition. Some metals are included as industrial minerals because their use is industrial rather than as a metal. Sulfur is now predominantly extracted as a by-product of cleaning natural gas, one of the world's major energy fuels. Production of industrial minerals has been and remains important to the rural economy of New Mexico. Industrial minerals constitute nearly 40% of the more than $2.8 billion generated by mineral production in New Mexico in 2013 (Table 1, see APPENDIX). In 2015, some 240 mines were registered in New Mexico. This total includes 25 industrial mineral operations and 189 aggregate operations. New Mexico leads domestic production in potash, perlite, zeolite, and travertine. Other industrial minerals production from New Mexico includes aggregate, humate, pumice, gypsum, salt, common and fire clay, scoria, limestone, fly ash, cement, magnetite, silica, and decorative stone. Additional production statistics are in Harben et al. (2008). Major industrial mineral districts are shown in Figure 1."

Jan 1, 2016

By V. T. McLemore

"Production of industrial minerals remains important to the rural economy of New Mexico. In 2014, 226 active mines and mills were registered in New Mexico and included four coal, eight potash, 11 metal, 33 industrial mineral and 170 aggregate and stone operations. New Mexico leads U.S. domestic production of potash, perlite, zeolite and travertine. Other production includes aggregate, humate, pumice, gypsum, salt, common and fire clay, scoria, limestone, fly ash, cement, magnetite, silica and decorative stone. New Mexico also has the potential for additional production of industrial minerals. One company is exploring for garnet. Cretaceous black sandstones in the San Juan Basin have drawn interest for titanium, rare earth elements (REEs), niobium and zircon, and other REE deposits are being explored. REE-thoriumuranium veins have been found in the Gallinas, Capitan and Cornudas Mountains and Laughlin Peak-Chico Hills. Exploration for beryllium has occurred in the Ojo Caliente No. 2, Cuchillo Negro and Victorio mining districts. Companies also are examining high-calcium limestone and high-magnesium dolomite for potential development, while aggregate continues to be important in urban areas and along highways. IntroductionIndustrial minerals and rocks are literally the building blocks of our way of life. They are an exceptionally diverse and vital group of raw materials that underpin almost all aspects of human activity, infrastructure and standard of living. Industrial minerals and rocks are used in the manufacture of many products, from ceramics to plastics to refractories to paper. Although industrial minerals permeate nearly every aspect of daily life, their presence and their roles are typically invisible. A widely used definition of industrial minerals and rocks is “any rock, mineral, or other naturally occurring substance of economic value, exclusive of metal ores, mineral fuels, and gemstones: one of the nonmetallics” (Bates, 1975). This definition includes the important construction materials sector as well as specialized industrial minerals, but complex interactions between consumer industries produce a number of apparent anomalies to this definition. Some metals are included as industrial minerals because their use is industrial rather than as a metal. Sulfur is now predominantly extracted as a byproduct of cleaning natural gas, one of the world’s major energy fuels.Production of industrial minerals has been and remains important to the rural economy of New Mexico. Industrial minerals constitute nearly 41 percent of the more than $3.1 billion generated by mineral production in New Mexico in 2014 (Table 1). In 2014, 226 active mines and mills were registered in New Mexico and included four coal, eight potash, 11 metal, 33 industrial mineral and 170 aggregate and stone operations (New Mexico Mining and Minerals Division, 2015a). New Mexico leads U.S. domestic production in potash, perlite, zeolite and travertine. Other industrial minerals production from New Mexico includes aggregate, humate, pumice, gypsum, salt, common and fire clay, scoria, limestone, fly ash, cement, magnetite, silica and decorative stone. Additional production statistics can be found in Harben et al. (2008). Major industrial mineral districts are shown in Fig. 1."

Jan 6, 2017

By Andrea M. Ouchi

A major focus of ground control research presently being conducted by the Geomechanics Group in the University of British Columbia Mining Engineering Department is to incorporate weak rock masses (RMR76 less than 50) into existing empirical design relationships. An emphasis is being placed upon the updated span design curve/critical span graph originally developed at UBC. The original database has been augmented by mapping of one mine in Montana and of several mines within the Carlin and Getchell Trends of Nevada. In addition, a neural network analysis has been performed and modifications of the span design curves at the lower RMR76 range have been made. The common factor in all the above mentioned mines is a weak back and/or walls. In most cases, the ore zone is the weakest rock unit and must be dealt with to safely extract the mineral bearing rock. This work attempts to provide rock mechanic tools that will enable a mine operator to make economic decisions that will also ensure a safe working environment.

May 1, 2004