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By Harrison R. Cooper

Composition data is needed as input for executing process control and management of particulate separation for flotation control. While requirements for composition data can be satisfied in many cases by manual sampling and analysis, automatic sampling and assay systems are now viewed as justified for all but the simplest or smallest processes. On-stream X-ray fluorescence analysis (XRFA) has satisfied requirements for the main portion of metalliferous sulfide ore flotation processes as XRFA technology evolved in reliability and sophistication from its beginnings in the late 1950's. In recent years, advanced on-stream analysis technologies have reached levels of development suitable for use in process control to increase efficiencies of important processes in mining and minerals industries such as coal fines flotation and industrial minerals beneficiation (particularly phosphate beneficiation) where XRFA methods have been inapplicable. Recent technical developments pertinent to use of advanced technologies as well as improvements to established on-stream composition analysis methods are discussed.

Jan 1, 1989

By Fan Yang, Meigui Yi, Lan Xiang, Zhuoying Yang

This paper reported the calculation of the reaction heat in titanium-bearing blast furnace slag (abbreviated as TBFS)-H2SO4 system based on estimation of thermodynamic data of CaTiAl2O6 by mechanical mixture model. The thermodynamic analysis indicated that CaTiAl2O6 was more stable than the corresponding ternary oxides as CaO·TiO2, CaO·Al2O3, and Al2O3·TiO2. TBFS-H2SO4 system was highly exothermic since all of the reactions involved in the system were exothermic. For example, the increase of temperature from 25 to 200°C led to the increase of the release of the reaction heat in TBFS (100.0g)-H2SO4 system from 181.28 to 189.73kJ. Eighty-five to 90%of the reaction heat in TBFS-H2SO4 system was contributed by the reactions among CaTiAl2O6, CaTiO3, CaMgSi2O6, and H2SO4.

Feb 1, 2021

By V. Angelatou

In the present study, the possibilities of use of natural zeolitic tuffs from the Skaloma area, Rhodope prefecture, Greece, for the removal of Pb and Zn ions from aqueous solutions has been studied. The equilibrium data were examined for different grain sizes, pH?s and initial concentrations. An apparent kinetic study was also carried out for different time intervals at constant temperature and pulp density. For the chemical equilibrium study the Freundlich isotherm was used. The experimental results verified the favored behavior of zeolite on lead ions and the quick kinetic of the process whilst the efficiency of the ion exchange on zinc is rather limited. The grain size of the material did not greatly affect the performance of the process. The removal of metal ions worked better at lower pH. The Freundlich isotherms are in good agreement with the experimental data.

Jan 1, 2006

By V. Nasri, P. Jarast, M. Bakhshi

The Montreal metro Blue Line Extension toward the northeast consists of the construction of five new underground stations. The project includes 6 kilometers of the tunnel which will be constructed using a Tunnel Boring Machine (TBM). In line with the commitment to integrating sustainability best practices, Envision verification is pursued this project. The Envision reference framework was developed to cover all the sustainable development aspects of an infrastructure project and each phase of its life cycle (planning, design, construction, operations and maintenance, and end-of-life). As a part of this endeavor, low-carbon concrete and shotcrete mixtures are proposed for the linings of TBM and SEM tunnels as well as stations and auxiliary structures. The CO2 emission of the low-carbon concrete and shotcrete mixtures were compared with their typical mixtures and the total CO2 emissions reduction related to the tunnel lining is determined. The study is of strategic significance for achieving emission reduction in the tunnel industry.

Jun 13, 2023

By Vaughn Astley, Hassan El-Shall, Ponisseril Somasundaran, Regis Stana, Patrick Zhang

In the past, when phosphate rock quality was good, few paid attention to any of the impurities or other qualities associated with phosphate rock. In general, they had little or no effect on the ability to make the phosphate products for the market. However, as phosphate rock quality declined, it was apparent to the rock consumers that the individual impurities had a significant impact on their processes. FIPR is presently funding an analysis of operating plant data to determine the range of the effects of rock impurities on production plant performance. The study will not be completed until 2002. IMC has agreed to share some of the information they had developed in the early 1990s.

Jan 1, 2002

By J. P. Mogan

As diesel exhaust contains a mixture of several materials of varying degrees of toxicity which interact to a currently undefined extent in their effects on health, the prescription of a quantity of ventilating air to dilute the exhaust to a safe level is necessarily, to some extent, arbitrary. Some jurisdictions rely on the application of a safety factor to a single "governing" component (usually nitric oxide for most modern diesel engines). Others specify that the total of the "adjusted" concentrations (actual concentration divided by maximum permissible concentration) not exceed "one" for related constituents (irritant gases for example). Neither of these approaches, however, takes account of the interaction of the gaseous constituents with diesel soot (although many studies verify such interactions), nor do they provide any economic incentive for reducing pollutants which are not included in the criteria for ventilation. Because of these factors, the Canadian Department of Energy, Mines and Resources awarded a contract for a study of the current literature bearing on the "Health Implications of Exposure of Underground Mine Workers to Diesel Exhaust Emissions" (1). One goal of this study was the formulation of a new ventilation criterion. The contractors, Ian W. French and Associates, studied more than 1500 literature citations which they interpreted in a 350 page report and summarized in a companion 1600 page annotated bibliography. In the recommendations section of the report, they defined a new 'health effects index' or ventilation criterion "V" as follows: [ ] The contractors consider that a "V" between 3.0 and 4.0 poses a moderate threat to health which could be alleviated by the use of protective equipment such-as filter helmets. If V exceeds 4.0, an increase in ventilation quantity to reduce the pollutant levels is indicated. In the case of mines with a quartz content in excess of 20% in the ore, the contractor recommends that a term. [Quartz]/ [Threshold Limit Value Quartz] be added to the equation, and [2.0 = ?v? = 30] be the range justifying protective equipment, with added ventilation if "v" exceeds 3. A degree of pragmatism was inherent in the development of the equation, as the contractors recognized that the components of the index, if it is to be useful in the near term, should be within current routine underground environmental assay capability.

Jan 1, 1980

By William Gleason

"Despite the difficult economic climate for the mining industry, more than 6,300 people joined SME for its 2016 Annual Conference & Expo in Phoenix, AZ, Feb. 21-24.Nearly every commodity has been bruised and battered during the past year, leading to one of the more difficult cycles for the industry in the past decade. Coal has taken some of the hardest hits and other commodities, such as copper and iron ore, have felt the sting of a slower growth in China and an oversupply on the market.The difficult conditions could not be ignored, but they did not deter SME from offering a forum for the industry to share knowledge, network with peers and learn about the best products and practices while visiting the sold-out exhibit hall (844 booths and 627 vendors) or while attending any of the 121 technical sessions that were offered.The current state of the industry was one of the overriding themes of the conference and during the challenging times there are often cutbacks as operations look to become leaner and more efficient, however, there is one area that cannot be cut – health and safety.The conference kicked off with a fascinating presentation from Colonel Mike Mullane, a former NASA astronaut who, in 1978, was selected as a Mission Specialist Astronaut in the first group of space shuttle astronauts. He completed three space missions and logged 356 hours in space aboard the shuttles Discovery and Atlantis before retiring from NASA and the U.S. Air Force in 1990.In his speech to a packed audience, he warned of the dangers of cutting corners to get the job done more quickly by guarding against the “normalization of deviance.”Normalization of deviance is a long-term phenomenon in which individuals or teams repeatedly accept a lower standard of performance until that lower standard becomes the norm. Usually, the acceptance of the lower standard occurs because the individual or team is under pressure (budget, schedule, etc.) and perceives it will be too difficult to adhere to the original higher standard. Their intention may be to revert back to the higher standard when this period of pressure passes. However, by getting away with the deviation from the higher standard, it is likely they will do the same thing when the same stressful circumstances arise again. Over time, the individual/team fails to see their actions as deviant."

Apr 1, 2016

By Shawn Healey

The Mineral Hill Mine, owned and operated by TVX Gold Inc., is located in the Beartooth Mountains, 5 miles north of Gardiner Montana, U.S.A., which is the north entrance of Yellowstone National Park. Mining is carried out underground using ramp attack cut and fill as well as room and pillar mining. The mine currently employs approximately 145 people and is producing 550 tons per day at a grade of around .21 oz/ton.

Jan 1, 1996

By William F. White

It is a pleasure to have the opportunity of being here today to discuss the application of horizontal filters in the metallurgical industries. The use of horizontal type filters has been limited in metallurgical plants. However, in the recent past there have been new designs of this type equipment which greatly broaden their field of application. Through their use in many applications, important economies can be achieved over more conventional methods. The first of the modern continuous horizontal filters was initially developed by Oliver United Filters as their scroll type horizontal filter. This was an outgrowth of the old Oliver Sand Table that was limited to very coarse, free filtering pulps containing no appreciable amount of fine particles. The sand table was rather limited in application. The later continuous scroll type horizontal filter provided for a reverse air blow after discharge which reslurried the heel remaining and permitted the filtration of pulps containing finer particles. In the manufacture of phosphoric acid by the ?wet? process, the filtration of gypsum from the strong acid presented an extremely difficult filtration problem due to blinding of the filter media caused by crystallization of the soluble salts contained in the acid. A filter which allowed for continuous cloth washing was required, and this led to the development of the continuous pan type, and travelling belt type horizontal filters which provided for this need. Among the filters developed were the Prayon by Engineering and Industrial Corporation of Luxembomg for use in their phosphoric acid plants. They are one of the largest manufacturers of phosphoric acid in Europe. The Dorr-Oliver Traveling Pan Filter was also developed by Mario Giorgini, Manager of Dorr-Oliver?s Italian subsidiary, for use with the Dorr Company?s phosphoric acid process. Basically, there are four existing types of horizontal filters in commercial use at this time: The scroll discharge non-pan type, the continuous belt type (Lurgi), rotary pan type, and the traveling belt type. The construction and principle of operation of these various filters will be discussed.

Jan 1, 1958

By Arafat Ghosheh, Yousuf Abu-Rish, Darwish Amara, Mohammed Baderkhan

The Jordan Phosphate Mines Company is one of the world's major phosphate rock and phosphatic fertilizers producers (the second largest phosphate rock exporter), with ore reserves exceeding 2 billion tonnes, mainly located in the Eshidiya area. The Eshidiya phosphate deposits, 120 km north-east of Aqaba, are of sedimentary origin (as are all phosphate ore in Jordan). Three exploitable beds (Al, A2, and A3) with variable content of P205, CaO, SiO2, etc., are processed in order to produce 68-70,73-75, and 75-77% TCP grades. The A3 bed, which is characterized as the most siliceous containing 40-48% TCP, requires physical beneficiation using wet scrubbing, screening, and desliming by hydrocylone, followed by anionic conventional flotation to achieve 75- 77% TCP grade. For the last 15 years extensive laboratory and pilot tests (including physical, chemical, and mineralogical studies) were carried out. After operating the industrial plant, certain modifications were deemed necessary to adjust the operational parameters and the final flowsheet, which was followed to obtain the targeted quantity and quality of concentrate.

Jan 1, 1999

By R. Ciccu

Permeable reactive barriers (PRB) are one of the most promising systems for groundwater remediation. PRB are constructed with the purpose to intercept the contaminated flow and to degrade it as a big reactive filter. The most common type of reactive barriers is realized by excavating a trench and by filling it with a substance able to treat the contaminants dissolved in the water. Another type of PRB is obtained by realizing a line of wells in which chemically active compounds are injected. A new method for barrier construction has been studied at DIGITA?s laboratories. It makes use of the waterjet technology to increase soil permeability and to inject active compounds. This technology is especially suitable in the case of deep contaminated aquifers where traditional construction methods are difficult to apply. The paper describes the experimental apparatus especially designed and constructed and the activities carried out to investigate the relationship between waterjet operative parameters and the penetration of the jet in the soil. In conclusion, on the basis of the experimental results, the economical feasibility of the technique is evaluated.

Jan 1, 2008

By Gregg Wilkerson

The Blind Springs Hill pumice beds are located 5 miles southwest of Benton, California in the foothills between the Benton Mountain Range and Blind Springs Valley. The best exposures of the pumice are in an area 0.75 miles west of Blind Springs Hill. The pumice is Quaternary ejecta material which came from the rhyolitic volcanoes in the Glass Mountain-Volcanic Tablelands area of Mono County. The pumice beds occur in two distinct layers separated by an unconformity. The upper layer is 0 to 11 feet thick and consists of coarse subangular pumice fragments, some of which are over 1.75 inches in diameter. The lower bed is medium to coarse grained with subangular fragments up to 1.0 inch. The lower bed is 0 to 9 feet thick. Overburden at the Blind Springs Hill deposit varies from 0 to 15 feet. There are approximately 1 million cubic yards of material in the deposit that can be mined. The size distribution in the deposit is mostly fine with only 10.6% of the pumice fragments being over 0.5 inch in diameter, the minimum size needed for stone-wash or acid-wash applications. Suitability of pumice for the textile industry is quantified by standard 15-minute abrasion and absorption tests. In the Blind Springs Hill deposit, the plus 0.5 inch fraction has an abrasion loss of 33% which is too high for stone-wash application but it has an absorption capacity of 36% which makes it suitable for acid-wash applications in the textile industry. The abrasion and absorption properties of this deposit are within the range of those which have been measured for other pumice deposits within the United States.

Jan 1, 1995

By Robert S. Lehto

Zinc concentrates received in La Oroya zinc refinery are marmatitic in nature, contain about 11% iron and traces of other metal values, Figure 1 shows the zinc circuit. The calcine from the roasted concentrates is leached in spent zinc electrolyte. Major part of the impurities is iron which has been oxidized to its trivalent form, This is the origin of the zinc leach residue for which the ZILERET process was developed and so named. The impure liquor from the leach is sent for purification and thence to electrolysis- zinc deposits on aluminum cathodes from which: it is stripped, melted and cast into slabs Typical assays of zinc calcine and leach residue are given in Table 1. Metal values contained in the leach residue, without counting any value of iron, amount to roughly $130 per short ton.

Jan 1, 1969

By Sean E. Armstrong, Deepak Malhotra

The current trend in gold ore processing is the development of lower grade or highly refractory deposits. The perplexity of treating low grade oxidized ores has been adequately addressed by heap leach technology. However, refractory gold ores are very difficult to positively characterize the gold association within the mineral matrix. Gold accompanied with refractory sulfitlc or carbonaceous mineralization can often be sub­micron In size and occur interstitially. Mineralogical examination of these ores Is difficult, expensive, and occasionally Inconclusive. Hence, the metallurgist Is given little information for the selection of processing alternatives. The purpose of this paper Is to demonstrate the use of diagnostic leach procedures to assist the metallurgist' s decision-making process to solve some of these problems. By sequentially liberating and/or leaching gold associated with specific minerals, the amount of recoverable gold in each stage can be determined. Through careful interpretation of the results obtained by diagnostic leaching, the metallurgist can devise a flowsheet for treating the ore or solve a problem at an existing plant

Jan 1, 1992

By R. E. J. Putman

The past ten years have witnessed substantial development of electronic equipment for execution of process control functions. The methodology of giving instructions to the data-handling system and the organization of the system, both the equipment and instruction coding taken together, have developed simultaneously. Examples of the technology specific to the mineral processing industry can be cited. Approaches to system design developed for the Pinto Valley concentrator incorporating slave and master data processing have been described by Arney, and his associates (1974). Madge (1970) has described the hierarchical systems employed at the operations of Cominco Ltd. The Kennecott Garfield smelter is controlled by a system of microprocessors linked to a general purpose data processor (Marchant, et al., 1977). These systems provide innovative approaches to couple advancing technical capability in electronic data processing to the objectives of process management. The current state of the art described in this chapter is certain to require updating in the 1980's with the advances in technology anticipated.

Jan 1, 1979

By F. Palmay, R. D. Gwilym, P. Eng

INTRODUCTION As the experience in Canada indicates, it is becoming more and more common to evaluate major mining projects, especially those relating to uranium, with respect to their environmental effects. As part of this evaluation public hearings are becoming the rule rather than the exception. In this area the 1970's and presumably the 1980's can be characterized as the age of "Environmental Assessments" or "Environmental Impact Statements" which form the basis of these hearings. These documents tend to require significant amounts of research, data collection and effort in their preparation, and tend to be closely scrutinized by the hearing body and by groups in opposition to the project. This opposition is becoming more organized and sophisticated. The assessment or impact document, together with the evidence supporting it during the hearings can: (a) mean the difference between a lengthy and hence costly hearing and a smoother, shorter and less expensive one, (b) result in requirements for extensive modification at the expense of the proponent to his project, (c) result in the proponent being required to carry out extensive studies, research or monitoring programs, and (d) conceivably may in certain situations result in the project actually being turned down. Therefore, while on the one hand it is important to have available technical answers to concerns relating to uranium, its associated and perceived hazards, it is getting more and more important to be able to present these answers in both a written and oral format in such a way as to meet the criticism and concerns of the opposition, be they citizens in general or special interest groups including environmental lobbyists. JURISDICTION From a Canadian perspective, the first legal question to be answered is which level of government has jurisdiction over uranium mines in general and specifically over aspects relating to the environmental effects, including the health and safety aspects, of uranium mines and

Jan 1, 1980

By Barton Kelby Cross

In the early 1960's the feasibility of mathematical modeling was demonstrated in Northern Rhodesia and southwestern United States, where techniques were developed to use these models in a new approach to aid engineers in the estimation of ore reserves, mine designs, and financial evaluations. These rudimentary models closely followed the manual methods, producing ore reserves and production schedule estimates that were as accurate as the manual methods, yet were many times faster. Mines evaluated and designed using these new tools gradually came into operation during the 1970's and entered the phase at which production scheduling and ore-grade control became day-to-day problems. Management expected the number of operational engineers to be small because small planning engineering staffs had produced the original designs and operated the smaller high-grade pits. Unfortunately, the tools needed by the mine engineer to perform short-term production scheduling and ore-grade control were labor intensive; they had not yet been generally computerized. Several attempts to use the original or exploration model for these two functions were futile. While an exploration model based on data from exploration work proved sufficiently precise for overall mine design and long-term production scheduling, the model lacked the precision required for short-term scheduling and grade control.

Jan 1, 1979

By Sam H. Patterson

The advances in knowledge of world bauxite resources in the last few decades include contributions to the geology of deposits, discovery of large resources, shifts in availability, and changes in. the industry in response to political and economic pressure. Improvements in the understanding of geology have resulted from the larger numbers of geologists working on bauxite and better exchanges of information. The large deposits discovered are mainly the laterite type in tropical regions. These discoveries have led to major increases in bauxite resource estimates as well as to shifts in bauxite availability and in the ranking of producing nations. Changes resulting from political, environmental, and economic pressures have resulted in increased costs of bauxite and in renewed interest in potential nonbauxite sources of aluminum. Aluminum is produced from nonbauxite raw materials only in the U.S.S.R.; however, research on extraction processes or investigations of nonbauxite alumina resources has taken place in several countries.

Jan 1, 1984

By Williams R. Reynolds

Studies of the northeastern Mississippi bauxites were initiated primarily for the purpose of ascertaining the quality and quantity of the ore. Subsequently, this ore was found to have a rather dubious economic value as was previously suspected but never established in earlier economic reports (1, 2, 3). However, the quality of ore was found to be higher than previously thought. Even though the ore bodies were determined during the early stages of this study to be too thin, small and widespread for commercial production a continuation of the study was not abandoned. On the contrary, the present investigation was intensified concentrating less on the economic application and more on stratigraphy and genesis. Considering the ever increasing demand for aluminum products the northeastern Mississippi bauxite district which includes portions of Tippah, Benton, Pontotoc, and Union Counties may soon become, in spite of inferior quantities of ore, an attractive area for bauxite production. Presently, however, the meager quantity of ore discourages exploitation. On the other hand, these northeastern district bauxites are facies of more extensive units of lignite bearing high aluminum clays, and considering the advances in aluminum extraction from clay these clays may in the future beckon mining interest. The bauxite of the northeastern Mississippi district, mapped as a part of the Betheden Formation (4). has an outcrop trend along the county lines of Tippah and Benton Counties and the extreme western portion of Union and Pontotoc Counties. Studies of exposures and cores stratigraphically positions the outcrop between the middle Midway Porters Creek Clay and the lower Eocene Wilcox sands and

Jan 1, 1977

By Gary Beerkircher

WaterFlush Technology and WaterFlush crushing offers significant operational ben­efits in gold milling operations. WaterFlush crushing is the technology that Nordberg Inc. has developed, tested and proven in an actual operation during the 1980's. Patents have been obtained for both the process and the apparatus of implementa­tion. WaterFlush involves volumetric process controlled water flow into the ore feed cav­ity of a WF cone crusher. While the addition of water in itself is not new, the con­trolled amount of water coupled with the WF crusher operating parameters are revolution­ary. The WF crusher is a specially designed version of Nordberg's Omnicone crusher oper­ating at higher speeds, with a reduced ec­centric throw and higher horsepower capabil­ity. The results are increased capacity, higher crushing energy input and a finer crusher product. The WF crusher product is a slurry containing 40-60% solids by weight.

Jan 1, 1990