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By C. Okrusch, C. Roos, M. Akers, S. Rosenthal

Modern mining consistently faces controversy. Public sentiment impacts the permitting and development of mines, so a quality public relations (PR) program for mining companies may improve society’s impression of the mining industry. Developing mines face more permitting challenges than operating mines, which stems from a lack of societal trust given the history of mining and its impact on the environment. Two case studies were selected based on the type of public controversy they face to demonstrate how pervasive permitting issues are in industry. Both Pebble Mine, owned by Northern Dynasty Minerals (NDM), and Black Butte, owned by Sandfire Resources America Inc (SRA), experienced difficulties with their water permitting due to potential risks their mine developments posed to local fish populations. Pebble has, to date, failed in all of their attempts to become permitted due to concern for the water and the fish. Black Butte dealt with the same problems, on a smaller scale, but was able to become permitted. These two mines will be discussed in detail including local history, mine setting, mining history in America, prevalent culture groups, technology development, and intercultural communication competence (ICC). The mining industry needs to evaluate its ICC skills since ICC directly determines the effectiveness of PR. Based on Barna’s Stumbling Blocks for intercultural communication, methods for improving the mining industry’s PR will be suggested in the hope of easing the permitting process for future mines by developing ICC.

Mar 2, 2022

A belt of serpentinized ultrabasic rocks intrudes a moderately folded geosynclinal sequence of fine to coarse sediments, acid, intermediate, and basic volcanics as well as a batholithic mass of granitic rocks. The ultrabasic body contains small included masses of melanocratic and leucocratic rocks, together with chromium, copper, zinc, and nickel mineralization.

Jan 1, 1969

By Leonard H. Goldman, Harold E. Marr

The PGT uranium assay probe is a borehole tool developed by Princeton Gamma-Tech over the last several years. It has the ability to do an in-situ assay of uranium in the presence of any amount of disequilibrium. It has some advantages over coring including cost, speed of analysis, and accuracy. In this paper we would like to give a brief description of the measurement and then show some sample logs from South Texas. Uranium exploration and development is carried out primarily by gamma logging since uranium daughters are prolific emitters of gamma rays. The conventional gross gamma tool for uranium logging is limited in value because of the inability of this tool to distinguish uranium from its daughters and other naturally occurring radioisotopes, such as potassium and thorium. This problem becomes severe in cases of disequilibrium. Disequilibrium, in a geological context, is defined as the condition when the gamma radiations from the daughter products are being emitted in a location different from that of the parent uranium. In the decay chain of uranium almost all the gamma radiation emitted in the entire chain comes from the daughter product, bismuth-214. Bismuth-214 is separated from uranium by several long-lived isotopes that are chemically active and have different physical properties, often resulting in shifts in the location of bismuth- 214 relative to the parent uranium. In the United States orebodies exhibiting disequilibrium are a common occurrence and the use of a gross gamma log to delineate uranium orebodies can lead to errors. At present the solution to the disequilibrium problem is extensive coring followed by chemical analyses of the cores. There are several drawbacks in using this technique. First is the high cost of coring, the second is the fact that no results are available for days, or typically, weeks after the drilling is done. Thus for development work, coring and drilling must be done on a grid basis and many additional holes are cored to ensure that the entire orebody is mapped. Another disadvantage to cores is the fact that a small volume is sampled, the volume of the core itself. This leads to problems in the mapping out of the orebody when the ore de- posit is not very homogeneous. The PGT probe described in this paper is a new solution to the disequilibrium problem. Basically, the probe measures radiations that come almost directly from uranium itself. The first daughter of uranium, which is protactinium-234 (Pa-234), is only separated from uranium by a 24-day half-life and no disequilibrium problems build up in such a short time. The PGT probe measures the intensity of a one MeV gamma line emitted by Pa-234 and, using this information, calculates the concentration of uranium. The PGT probe is 24" in diameter and 12 feet long. The probe contains a microprocessor which passes the information to a larger minicomputer in the truck. All data is analyzed on site, and the results from a high speed printer are presented to the geologist. Data is also available on 9- track IBM compatible tape for further processing. The PGT probe output is linear with uranium concentration. The only correction factor is for borehole size, and that only becomes important in boreholes bigger than seven inches in diameter. Dead time is compensated in the probe itself and no problems have been encountered in ore zones up to several percent UjO8. In addition to the uranium assay, a conventional gross gamma log is plotted alongside. Grade thicknesses for zones above cutoff are calculated as well as disequilibrium factors. COMPARISONS During its commercial operation PGT logged a series of 18 holes that had been cored and assayed. All of the holes in this series were logged in normal operation by regular field operators. The time to log each hole was generally under an hour, and in typical operation a PGT logging truck will do between 7 and 8 holes a day. The results of the comparison of the PGT and the core assays are presented in a series of figures showing plots of the PGT assay, core analysis and gross gamma measurements. The first three figures show individual holes with the gross gamma plotted along with the core and the PGT assays. All three logs were from holes on the reduced side of a rollfront deposit in South Texas. In Figure 1 we see the two wings of the roll- front at 143 ft and 150 ft separated by a barren zone. The wings are well defined both by the PGT assay and the core. There is approximately a one foot shift which can be attributed to drilling errors. The gross gamma is showing a rather severe discrepancy, being considerably lower and not showing the barren zone. The grade thickness calcula-

Jan 1, 1980

By Steven I. Baskin

Cyanides are utilized in many industrial applications including preparation of chemical intermediates, electroplating, and' mining, Cyanide has been utilized in chemical warfare operations as well Cyanide is also synthesized and found in plants and animals including man where it is thought to perform multiple functions. A variety of enzymes are known to detoxify cyanide under different conditions. These include rhodanese, 3-mercaptopyruvate-sulfur transferase, thiosulfate reductase, cystathionaseand albumin. Cyanide appears tQ exert its toxic effect primarily by inhibiting cytochrome oxidase? although other enzymes are also inhibited. Therapeutic antagonist categories to treat cyanide include methemoglobin formers such as nitrite, sulfane-sulfur donors such as thiosulfate, metal salts or complexes such as cobalt and cyanohydrin-forming compounds such as dihydroxyacetone or alpha keto-glutaric acid. Advantages and disadvantages of each category will be discussed. Newer compounds under development have been found that may allow for prophylactic therapy for cyanide poisoning with minimal side effects; In addition, portable co-oximetry devices may provide real-time measurement of cyanide in field units.

Jan 1, 1998

By E. Best

In 2003, Phelps Dodge Mining Company decided to pursue the design and construction of a Central Analytical Laboratory to provide chemical analyses for their Arizona and New Mexico operations. This centralized approach was selected in place of refurbishing six (6) older laboratories that operated at the various Phelps Dodge sites, and which would not have permitted full automation and use of robotics. The new lab was designed by the Process Technology Center (PTC) Material Characterization Group in cooperation with IMP Group. The Central Analytical Service Center (CASC) encompasses fully automated sample preparation of blast holes and geological samples weighing up to 15 kg/sample. The CASC also includes the first "wet chemistry module" worldwide to be operated by robotics systems to perform Total Cu, Acid Soluble Cu, and Quick Leach Tests (QLT), and a fully automated lab for electrowon copper cathode. The new lab also offers flexibility for handling specialty samples and analyses by either semi-automated or manual mode. Data handling and transfer is accomplished using the commercially available StarLIMS system. Commissioning was accomplished within five (5) months of startup during which the CASC also handled 86% of a full production load. The 24/7 lab operation has already exceeded its design capacity, has achieved considerable savings in operating cost, reduced sample preparation errors, and significantly increased analytical quality.

Jan 1, 2007

By B R, R Brooks, R Simcock, R Stewart

As environmental costs incurred by the mining industry become increasingly subject to critical analysis, new technology is necessary to ensure the further development of good relationships between the industry and community. Phytoremediation and phytomining are technologies that have the potential to capture the imagination and approval of the public. Phytoremediation , the in situ use of plants to extract heavy metals from a contaminated substrate, could offer an environmentally and cost-friendly alternative to traditional remediation techniques. Phytomining is the in situ removal of metals from a contaminated site or subeconomic orebody with the additional aim of recovering from the plant an economic amount of metal. Plants used in such operations, hyperaccumulators, accumulate large quantities of one or more target metals in their above-ground herbage. Upon harvesting and incineration, this plant material yields a low-volume, sulphide-free æbio-oreÆ, which can either be safely disposed of, or if the metal is of sufficient value, smelted. Investigations into the economics of phytomining nickel from ultramafic (serpentine) soils, showed that Alyssum bertolonii and Berkheya coddii could remove over 100 kg of nickel per hectare per annum from land with nickel concentrations well below the cut-off grade for conventional mining. It also appears possible to æinduceÆ the hyperaccumulation of gold into plants growing on gold tailings, or on stockpiled, low-grade gold ore. The plants used for phytoremediation and phytomining are useful colonisers as they are necessarily hardy and withstand extremes of salinity, metal toxicity and water stress that hinder the success of current revegetation procedures. As part of a rehabilitation operation, these plants may alter the geochemistry of a substrate making it more amenable to the growth of native species that should be used to restore a mining site to pre-operating conditions.

Jan 1, 1999

By Barrick Pierina, John Frostiak, Igor Gonzales, Kenneth G. Thomas, Ken Manning

"1.0 SummaryThe Pierina deposit was acquired in August 1996 when Barrick Gold Corporation purchased Arequipa Resources, a junior mining company with extensive land positions in Peru. At the time of acquisition, Arequipa had developed two exploration tunnels and drilled 9 exploration holes on the property. Metallurgical tests, conducted on samples taken from the tunnels and the exploration holes indicated that the ore was amenable to heap leaching. Barrick’s exploration team recognised from the outset, the potential of the mineralisation and convinced Barrick’s senior management that this was indeed a world class deposit that should be pursued. On November 25, 1998, the first dore was poured at Pierina, 27 months from the time of acquisition. During that period Barrick completed its exploration programme, prepared a development plan including capital and operating costs, production profiles and cash flow forecasts, and a schedule to develop a mine and construct a leach pad and gold recovery plant, including all supporting infrastructure. All permits and environmental approvals were obtained and all necessary land was acquired. The project was completed on schedule and under budget. This was the first greenfield mine development for Barrick outside of North America.This paper details, mainly, the research and development, engineering, construction and commissioning of the metallurgical process facilities.2.0 The Develonment ProgrammeImmediately after the acquisition, Barrick began the process of gathering information required to prepare a project development plan. Kilborn Engineering was retained to assemble all of the information collected and collated into a development plan document. This document was completed by June 16,1997. The objective was to bring the mine into production as quickly as possible with critical activities identified as follows:"

Jan 1, 2000

By J P. Bolduc, P. E. Pelletier

Preceded by brief general considerations such as the development of the mining industry in. the Province of Quebec, the choice of plant location, the types of problems studied etc., the paper gives a complete description of this new research and treatment center for metallic, non-metallic and asbestos ores. Facilities for carrying out operations in the three sections of the plant -the sampling section, the ore treatment section and the asbestos section -are fully discussed as well as laboratory facilities for (a) the preliminary testing of ores prior to pilot plant treatment and (b) the grading and testing of asbestos fibre. AT THE beginning of the century, the annual value of the mineral production of the Province of Quebec stood at the $2,500,000 level. Twenty-five years later, it was just under $24,000,000. In 1950, half a century later, it was slightly in excess of $200,000,000. But in 1959, in the span of only nine years, it

Jan 1, 1962

By Larry Whittle

Gold milling activities generate waste streams containing dissolved metals and cyanide, among other contaminants, that require some form of treatment prior to discharging to the environment. To date, this treatment has involved the destruction of cyanide through natural degradation, chemical oxidation, or a combination of both followed by the precipitation of metal hydroxides. Although these processes have been proven to be capable of achieving. regulatory levels for metals and cyanide, they often generate significant levels of cyanate and, at times, ammonia, that may be toxic to rainbow trout and thus undesirable for regulatory compliance. Tallon Metal Technologies Inc. (Tallon) has developed Vitrokele™, a chelating resin that has the ability to capture metals (including gold), both total and weak acid dissociable cyanide, as well as thiocyanate from both slurries and solutions. The loaded resin is eluted and returned to the recovery circuit while metals and cyanide are recovered from the eluent stream. This process was demonstrated at pilot scale at B.P. Resources' Hope Brook Gold Mine in Newfoundland, and more recently at Canamax's Bell Creek Mine near Timmins, Ontario. The results from these pilot programs showed metal and cyanide recoveries of 99% or more with the concentration of cyanide and metals in the effluent reduced to levels with minimal or no toxicity to rainbow trout. Furthermore, neither cyanate nor ammonia were generated from the process. The loaded resin was effectively stripped and re-introduced to the recovery circuit; cyanide was captured in the eluent stream and made available for recycling to the mill leaching circuit; and metals were captured for re-use, sale or disposal. This paper summarizes the results obtained from the pilot tests at the Bell Creek and Hope Brook Gold mine sites.

Jan 1, 1992

By Cocks T

The 15-year long debate between the industry, Government and Aboriginal people about the rights and wrongs of Land Rights, the right of Aboriginal people to control development on their land and the relationship between the parties, has been long and often bitter. It has so far been a war of words and often the truth has been the first casualty. This paper looks at the debate and presents the perspective of Aboriginal people, as well as looking at how the industry and Aboriginal people can work together for everyone's benefit. It addresses such matters as: ò why Aboriginal people believe they have the right to control development on their land; ò the perception that Aboriginal people are anti-development; ò the perception that Aboriginal land is 'locked-up'; and ò how companies can negotiate with Aboriginal people.

Jan 1, 1994

By J. W. Motter

Currently, virtually all new electric power generation systems under construction are designed with natural gas as the primary fuel. Factors driving these construction decisions involve sustained low prices for natural gas, environ-mental (and consequent regulatory) risks associated with the use of coal for power generation, and relatively high costs of construction for conventional coal-fired power plants. Despite the unarguable abundance of coal in the US. and worldwide, a fundamental question arises: What will be the role of coal in electric power generation in the 21st century? Congress, recognizing the vital and strategic importance of preserving the coal option for electric power generation, authorized the Clean Coal Technology Program. This pro-gram, with original funding in excess of $2,500 million, is intended to promote the demonstration and commercialization of a new generation of clean, efficient coal-based energy technologies through collaboration and partnering with private industry. The two technologies being demonstrated under this program which are the key to the continued use of this nation's huge coal reserves are coal gasification and the pressurized fluid bed. Either or both of these technologies, coupled with a combined cycle will pro-vide the continuing future coal option, while responding to increasingly more restrictive environmental standards. Recent Congressional budget-cutting efforts, however, could threaten the effectiveness of that model program, and ultimately other subsequent government-industry collaboration.

Jan 1, 1996

By K. Hanson

When done properly, benchmarking is an extremely effective tool for assessing ones performance, finding areas for improvement, and identifying strengths. However, when done improperly it can be an exercise in futility and result in incorrect observations and conclusions. A primary pitfall of benchmarking is collecting too much unreliable information. Surprisingly, the evolution of data storage and the ease of data collection are not helping with better data collection. Instead, it is just allowing one to collect more information, while at the same time inundating one with too much data. Additionally, the process of data collection can be tedious and is often times delegated to the least experienced individual resulting in unreliable and incorrect data collection and entry. Another primary pitfall of benchmarking is metrics that are cost based or poorly designed. Cost based metrics typically involve comparing unit mining costs ($/tonne). Between mines, unit mining costs are not very well correlated and have become further complicated by significant regional cost variations and mining inflation in the last years. Likewise, poorly designed metrics lead to poor benchmarking results. Examples of poorly defined metrics include: metrics that rely on information that is difficult to collect, metrics that are poorly defined, metrics which are too site focused, and metrics that measure low consequence practices.

Jan 1, 2011

By Edward Burris, Terry Gorsuch, Joseph M. Hans

INTRODUCTION In any large earth-moving operation, good planning and management are necessary to complete the operational tasks promptly and successfully. When an earth moving operation is complicated by radioactive contaminants, normal earth moving techniques and procedures must be modified. Any planning and management, therefore, must include the radiological aspects of the operation. It was found that the radiological aspects dominated most of the planning and management activities and were extended to all facets of the decontamination work at the former Shiprock uranium millsite. These planning aspects are discussed and their use to develop a work plan is described. The management aspects are discussed and their use to establish a management structure are also presented. PLANNING Some method of procedure, formulated beforehand, was necessary to govern the decontamination work at the former Shiprock uranium millsite. This procedure was expressed in the form of a work plan which served several listed purposes. 1. It defined the work to be done and the sequence it would follow. 2. It was used as a yardstick to measure progress. 3. It was used to assign organizational responsibilities. Several factors were considered to aid in the development of the plan. These factors are discussed below: Goals It was established that radiation exposure was occurring to persons working at the millsite, and in an around the community of Shiprock, from airborne radioactive mill wastes and radon-222 exhaling from the tailings piles. The goal set for the decontamination work was to reduce on-site exposures to levels acceptable for the millsite occupants. The attainment of this goal would also have a substantial impact in reducing off-site exposures. The objectives necessary to achieve the goal were consolidation and containment of the wastes. The former objective implies decontamination of the millsite and environs, and the later implies stabilization of the wastes. In practice, a total and complete decontamination of the millsite and contaminated environs would be very difficult and costly. The costs for decontaminating them could be high enough that an alternative method might be more cost-effective for reducing human exposures (i.e, move the affected people away from the source). The interim guide "Radiological Criteria for the Decontamination of Inactive Uranium Millsites" was used for the decontamination criteria (EPA 74). Briefly, the criteria state that off-pile decontamination should be effective enough to reduce the net above ground exposure rate to less than 10 [u]R/hr for unrestricted use of the affected area. When decontamination cannot readily be achieved, the exposure rate levels could be relaxed to 40 [u]R/hr; however, the affected area has to be restricted. The second objective, waste containment, means isolating the wastes from the biosphere. Since no method of containment was available at the beginning of the millsite decontamination effort, temporary containment (interim stabilzation) became the objective. The tailings pile and decontamination wastes would be covered with clean fill. The interim stabilization should last from 5 to 10 years until the final disposition of the wastes will occur. The goal, therefore, would be achieved by decontaminating the off-pile areas to less than 10 uR/hr where practical. The decontamination wastes would be used to plate the surface of the tailings pile and would be covered with clean fill. Radiological Survey The radiologial survey is the key factor for planning a decontamination activity. The survey should delineate the spread and depth of the contaminants relative to the decontamination criteria. Surface wastes, in general, can be evaluated for spread and depth with reasonable radiation survey equipment. Subsurface wastes on the other hand can be missed entirely, as happened during the radiation survey at the Shiprock site, although numerous exploration holes were bored and dug. The survey results can be used to define areas that may not be amenable to decontamination because of complications or safety reasons. For example, no decontamination of the bluff base was to be attempted because of the possibility the bluff might collapse on the personnel and equipment. Contaminated bottoms of decant ponds on the flood plain were not removed because they would be slurried by ground water. Slurry removal was deemed inefficient because the contaminants would be scattered and no equipment was available for its transport. In summary, the radiological survey defines the boundaries of the decontamination work and provides

Jan 1, 1981

By Jung-Hum Lee, Young-Joon Lee, Eui-Joon Hong, Seon-Hong Kim, Chan-Dong Kim, Keon-Woong Jeong, Ki-Lim Kim

"Subsea tunnel needs to be built over 50km long to connect between nations and continents. However there are only 19 tunnels longer than 5km in Korea, and there is no history of constructing and operating a tunnel longer than 50km. As the concept of a subsea tunnel, which withstands high water pressure and has an extremely long length is completely different from that of a land tunnel, all kinds of the latest technologies for tunnel construction are required such as survey and analysis of geology, design and construction under high water pressure, ventilation and prevention of disasters within an ultra long tunnel. Therefore, this paper describes the determination of tunnel cross-section under a high speed railway, structural stability, ventilation and fire safety under construction and operation, etc. through the virtual project for the length of 108km subsea tunnel under high water pressure of maximum 20bars from Honam to Jeju island in Korea. 1. INTRODUCTION The Honam-Jeju virtual project is subsea tunnel project to link from Honam(land) to Jeju(island) extending the currently operating Honam high speed railway line, and the same express train(t=18, design speed 350km/h, total train length 200m) operating at Honam line is applied in this project. As Honam-Jeju site is approximately 80km in straight distance with 160m maximum depth, subsea tunnel project should determine the various issues such as air quality/ventilation, aerodynamics, temperature, drainage, fire & life safety, structural stability. Figure 1. is the plan of subsea tunnel, with be constructed using Shield TBM. This double tube-Single track is composed of cross passages (every 350m in general section and 40m in emergency station), service tunnel, pressure relief ducts (every 250m), cross-over tunnels, shafts and emergency stations. 2. ALIGNMENT AND SITE CONDITON This project is planned as an ultra long tunnel of total length more than 105km via existing islands between Honam and Jeju island because straight alignment requires an artificial island which has high cost and construction risk, by deep water depth, though this is the shortest distance (see Fig 2). Water depth and topography in project site is divided into two blocks by Chuja Island. In first block to Chuja Island, depth of the water is 40m on average and maximum 60m, which indicates gradual change of water depth relatively. Also, outcrop bedrock is widely distributed near island."

Jan 1, 2016

By C. M. Shigley

Tan record of the largest magnesium plant in the country utilizing sea water as a primary raw material stands as another victory in the struggle for large-scale production of pure chemical elements from the oceans. Bromine was the first element to be economically and commercially recovered when, in 1933, a six million pound per year unit was built on the Atlantic Coast near Wilmington, North Carolina, by the Ethyl-Dow Chemical Co.1 The bromine was reacted with ethylene to produce ethylene dibromide, a necessary associate of tetraethyl lead in ethyl antiknock fluid. Within eight years that plant was doubled and redoubled, and another large unit was put into operation at Freeport, Texas, taking bromine from the Gulf of Mexico. In 1940, in fortunate anticipation of the impending demand for magnesium and the limitations of the production from natural brines, the Dow Chemical Co. turned again to the sea, and designed and erected a plant at Freeport to produce 18,000,000 lb. of magnesium per year from sea water.2 In March 1941, two months after the new plant had been put into successful operation, construction of an 18,000,000-lb. Government-financed addition was started. Late in 1941, as a part of the $400,000,000 defense program intended to produce 600,000,000 t0 700,000,000 lb. of magnesium per year, Dow was asked to build and operate for the Government a 72,000000-lb. plant near its original plant at Freeport. Within a few days after the Japanese made their attack at Pearl Harbor, preparation of a site was started at Velasco, Texas, for the construction of the Texas plant of the Dow Magnesium Corporation-the largest known magnesium plant utilizing sea water as its raw material. Less than six months after the first piling was driven, urgently needed magnesium was in steady production. Five months later, the plant had exceeded its rated capacity. It remained above rated production until the general magnesium curtailment was applied to Government-owned plants in September 1944. Credit for the construction and operation record of the Dow magnesium plant must be divided among the efforts of a very determined group of men, an extremely favorable location, and a simple process. It is with the two latter aspects of the plant that this article will deal. The site for the new enterprise was chosen near Velasco, Texas, on property bordering the Brazos River at a point approximately 6 miles inland from the original magnesium plant and y miles inland from the Freeport Harbor on the Gulf of Mexico. This location was far enough away from the operating units to reduce both interference from construction and the vulnerability of closely bunched manufacturing operations to the then feared air attack. Yet the distance inland was not too great for the economical construction of a barge canal from the harbor to serve both the transportation of raw

Jan 1, 1945

By J. T. Nel

The establishment of a pilot plant for the continuous production of titania pigment and nano-titania is discussed. The plant was designed, constructed and operated on the Necsa site. The TiO2 production capacity is 7?10 kg.h-1 by the reaction of TiCl4 and O2at>1000°C. Liquid TiCl4 is sprayed under pressure into a plasma reactor where it evaporates and reacts with O2 to form TiO2. Process optimization has allowed for continuous production without any clogging or blockages. The primary advantage of the plasma-assisted process is the possibility to recover and recycle the chlorine values in high yield as Cl2 for use in the manufacture of TiCl4. The HCl formed in most conventional fossil-fuelled processes makes Cl2 recovery and recycling much more difficult. Particle size distribution analysis of the fine, white product revealed a d50= 125 nm. The raw product consisted of 60% rutile that could be increased to 80?100% rutile by post-annealing. The specific surface area (SSA) of the pigment was 8?20 m2?g-1(BET). According to the CIE colour index the ?whiteness? (L*>95) of the plasma-produced pigment was better than that of several commercially available pigments. The particle size could be manipulated by controlling the TiCl4 feed rate, gas flowrates, and the particle quench rate and residence time. Nano-sized TiO2 powders with a particles size (d50) as small as 50 nm were also successfully produced in this way.

Jan 1, 2010

"7.1. Glossary of the Platinum-Group Minerals7.1.1. IntroductionA glossary of the platinum-group minerals (POM) serves as a useful introduction to a chapter on their mineralogy. Earlier glossaries (Cabri, 1972, 1976) were prepared for different purposes and composed in a different manner. As for most mineralogical textbooks, from Dana's System of Mineralogy, 3rd Edition (1850) , to Fleischer's Glossary of Mineral Species (1980), this glossary is primarily a chemical classification, arranged here in two tables. Table 7.1 groups the mineralforming compounds of the six platinum-group elements (POE) according to their essential anion(s) or according to the nonPOE element in intermetallic compounds. Table 7.2 is a similar listing for the native metals and alloys of the POE. Both tables include unidentified POM considered to be bona fide new minerals requiring additional study for complete characterization and recognition (see Chapter 9*). Some information on the chemistry of the POM is given in the sections on X-ray data (7 .2) and ore microscopy (7 .3). Because the overwhelming majority of POM have been characterized by the electron microprobe, a more detailed account of representative analyses is given in Chapter 8**. The total POM listed in Tables 7.1 and 7.2 is about 100, after deleting some which would not qualify as discrete species if found today, but which are still recognized on historical grounds; e.g. iridosmine, osmiridium, platiniridium. Tables 7.1 and 7.2 also include 28 unnamed POM; included because they are considered to be probably new species (Cabri 1981 b). The referral scheme for unnamed minerals is the same as in Chapter 9. There are considerably more palladium minerals known than other POM; the proportion of total species (listed in Tables 7.1 and 7 .2) for the POE is: Pd 48%, Pt 21 o/o , Ru and Ir 9% each, Rh 8% and Os 5%. These proportions are in marked contrast to the estimated cosmic abundance, as compiled for average type C1 chondrite by Naldrett and Duke (1980): Pt 29%, Ru 20%, Pd, Ir and Os 15% each, and Rh 6%."

Jan 1, 1979

By LUIS ALBERTO TORRES-CRUZ

The assessment of liquefaction vulnerability is crucial to understanding the potential consequences of a tailings dam failure. The “Plewes method” is a relatively well-known and simple screening method to assess liquefaction potential based on results of cone penetration testing (CPT) which may be complemented with laboratory testing. The objective of the current work is to emphasise the screening nature of the method and its uncertainties when applied in tailings deposits. Specifically, the paper highlights the difficulties in assessing the intrinsic uncertainty of the method and the additional uncertainty that results from variations of the slope of the critical state line (λ10) along the depth of the CPT sounding. The results of the method are too uncertain for detailed characterisation of tailings even when a relatively low intrinsic uncertainty is assumed. However, the method characterises weaker soils with lower uncertainty (although still too high for detailed characterisation) than stronger soils. The uncertainty of the method is negatively affected by the relatively low λ10 values that are typical of nonplastic tailings. It is suggested that the results of the method should be presented in scatter plots in which the spread of the data is consistent with the uncertainty of the method.

Jan 28, 2021

By J. Gough M. D.

There are many points still obscure regarding the nature of coal-workers'- pneumokoniosis, but the interpretation of the disease has been greatly clarified in recent years. It is now known that exposure to fumes or gases or other conditions peculiar to coal-mining are not necessary factors in the production of pneumokoniosis. The same disease occurs in coal-trimmers working in the docks, and it is thus established that the inhaled dust is the primary factor. On the other hand, there is no completely satisfactory explanation of the distribution of the disease. Geological and petrological studies have not given an unequivocal explanation of the difference in incidence in different parts of the coalfield. It is an open question whether the quantity of dust inhaled is more important than its chemical composition. However, there is ample evidence from the medical side that elimination of dust and of tuberculosis from the environment of coal workers will be required to prevent pneumokoniosis. Much is being done with regard to elimination of dust, and a similar energetic action is required in regard to tuberculosis.

Jan 1, 1947

By Eric Konigsmann

"The Pogo project is located on the Goodpaster River, 38 miles north of Delta Junction in east central Alaska. Sumitomo Metal Mining and Teck Corporation are planning to develop a 2,500 ton per day underground mine and mill at Pogo. A preliminary resource of 5.5 million ounces of gold has been identified in two flat lying lenses. An underground adit has been developed to facilitate underground drilling of the deposit and to provide samples for bench and pilot scale metallurgical testwork.Flowsheet development included the evaluation of several processing options. The final flowsheet selected includes SAGhall mill grinding, gravity concentration with intensive cyanidation and direct electrowinning, sulfide flotation with ultrafine regrinding, and cyanide leaching and CIP gold recovery from the flotation concentrates. Flotation tailings will be filtered for placement in a dry stack storage facility or disposed of as paste backfill underground. All of the CIP tailings will be disposed of underground as paste backfill. A pilot plant was carried out to evaluate the proposed flowsheet described above and to confirm the gravity recovery predictions.Great care was taken in the development of the flowsheet and site layout concepts to mitigate the environmental impact of the proposed operation. An overview of the site water management concepts is presented and the impact of water issues on the process flowsheet is discussed."

Jan 1, 2002