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By U. Ulusoy

Surface roughness and acuteness are known as the two of the main properties of the particle morphology affecting the behavior of the powders in the process. Since the techniques used for the morphological characterization of powders by 2-dimensional microscopic measurement from the polished sections that have some disadvantages, the 3-dimensional analysis has often relied on measurements of particle morphology. A review of literature data was presented for high-grade barite and pyrite particles ground by ball and autogenous mills to determine the morphological properties using a new 3-D approach based on BET nitrogen gas adsorption and Permaran methods. Micromeritics Flowsorb II 2300 instrument which employs BET nitrogen adsorption technique was used for the specific surface area measurements and the roughness of the particles. Permaran (manufactured by Outokumpu Oy) was used for the measurements of airflow resistance of powder samples for the acuteness. Spherical glass beads were used as reference sample for the acuteness measurements. The obtained parameters, which are surface roughness and acuteness, were corre-lated with the floatability performance of those mineral particles. The flotation performances of those particles ground in different mills (ball and autogenous) were also evaluated by a Hallimond tube. The results showed that lower roughness and acuteness values caused higher flotation recoveries for both barite and pyrite particles that were tested independently in different type of the mills. In other words; particles with smooth surfaces resulted in better floatability for barite and pyrite minerals studied.

Jan 1, 2014

By Cuong V. Trang, Christopher A. Fleming

There has been greatly renewed interest throughout the gold mining industry over the last few years in cyanide recovery from gold and silver plant tailings. This interest has been spmred by two factors. Firstly, the increasing cost of destroying cyanide to levels that meet more and more stringent regulations for tailings impoundment or discharge to the environment. Secondly, many gold ore bodies suffer high cyanide consumption costs as a result of the presence of base metals (principally copper) that react with and consume cyanide during the gold leach. In most cases, the cost of recovering and recycling this cyanide from the tailings is signif­icantly lower than the cost of purchasing new cyanide. When this cost benefit is added to the lower costs of tailings detoxification, a compelling case can frequently be made for cyanide recove1y. A number of processes for recovering cyanide from gold plant barren solutions or pulps have been developed. Most of the processes require that the recoverable cyanide is first converted to the highly toxic hydrocyanic acid gas (HCN) and fears surrounding the handling of this compound have probably presented the great­est impediment to implementation of these processes.

Jan 1, 1998

By S. K. Kawatra, J. A. Halt

"Low-grade iron ores are finely ground and processed to recover iron-bearing minerals. However, the iron-rich powder is too fine to be used directly in blast furnaces and most direct reduction furnaces, and must be agglomerated or pelletized into a usable product called “pellets.” Bentonite clay has traditionally been used as a binder to make iron ore concentrate pellets, but it is expensive and contaminates the pellets. Organic binders may be a viable alternative to bentonite clay. This manuscript reviews organic materials that have been used to make iron ore concentrate pellets. Included are discussions on the development of organic binders, common pros and cons to organic binder use, organic binder structure and its effects on agglomeration, and additives to organic binders.IntroductionIron ore agglomeration turns finely disseminated, low-grade iron ores into a usable product, called pellets. During pellet production, fine-grained, iron-rich minerals are liberated from low-grade ores, concentrated, and agglomerated into round balls that are thermally hardened or cold-bonded to form pellets. Pellets are then transported to blast furnaces or direct reduction operations where they are used to produce iron; iron is further refined and shaped into the wide variety of steel-based industrial and consumer products in use today.Over the years, pellet production has become increasingly more prevalent with the increased exploitation of low-grade iron ores and increased iron and steel consumption around the world. In 2010, world iron ore pellet production was 388 Mt. It could be argued that the current pellet production process has been enabled by the use of binders – practical experience has shown that it would be nearly impossible to agglomerate iron ore concentrates using rotary drums and discs without using a binder."

Jan 1, 2015

By Sheila E. Daniel

"Since 1989, the Mine Environmental Neutral Drainage Program (MEND) has sponsored research into ways of reducing the environmental impact and financial liabilities associated with Acid Mine Drainage from tailings and waste rock. Toward this overall objective, Kilborn was contracted to review the use and applicability of passive treatment systems for acid mine drainage.Experimentation using passive systems to treat acid mine drainage has been ongoing since the early 1980's in North America. Passive treatments are generally considered an attractive alternative to active lime treatment, since they require minimal human involvement, no power, and only seasonal or periodic care and maintenance after establishment. Most attractive is that initial capital cost to implement a passive treatement system is generally low to moderate. Ongoing operating costs are similarly low when compared to active treatment systems.Passive treatment systems currently used, or under investigation to treat acid mine drainage include: anoxic limestone drains, aerobic wetlands, reed bed wetlands, compost wetlands, microbial systems and bioabsorption systems. These wastewater treatment systems utilize the chemical, biological and physical removal processes that occur naturally in the environment to improve wastewater quality, including: oxidation, reduction, coagulation, adsorption, absorption and precipitation; microbial activity; and, gravity aeration and dilution. The rates at which these processes occur determines the loading which can be treated and the effectiveness of the system.The results of our literature review will be summarized, and insight provided into the applicability of passive systems to treat acid mine drainage from Canadian Mines."

Jan 1, 1995

By Martin P. Corriveau

It is not news to anyone in the mining industry that federal action in the prevention and abatement of air pollution has seriously affected the industry both directly and indirectly. It is the purpose of this paper to review how the development of federal action is directly affecting the coal mining industry's number one customer, the fossil-fuel-fired steam generating power plants and, consequently, the industry itself indirectly. In essence, Public Law 84-159 of 1955 as amended by the Clean Air Act of 1963 and its revisions in 1967 and 1970 progressively tightened federal coordination and management of air pollution control programs throughout these United States. The Environ- mental Protection Agency (E.P.A.) set up to direct the programs was charged to establish National Air Quality Standards, Standards of Performance for New Stationary Sources, and National Emission Standards for Hazardous Air Pollutants.

Jan 1, 1973

By J. R. Giegerich

"IntroductionMINING operators in common with other operators are confronted today with two serious problems, shortage of experienced workmen and rising costs. The following review of practices at the Sullivan mine of The Consolidated Mining and Smelting Company of Canada, Limited, outlines certain measures that have been responsible, during recent years, for minimizing the effect of these two problems. The paper is divided into three main sections:( 1) Training programmes and job studies( 2) Improved mechanization and equipment( 3) Large-scale methods of operationTraining Programmes and Job StudiesJob TrainingJob training courses were introduced at Cominco immediately after the last war and proved to be a great benefit to the operations. There were three courses given, Job Instruction Training, Job Safety Training, and .Job Relations Training. These were spread over a period of two years and were taken by all operating supervisors and some key operators.The courses were introduced by a trained instructor from the British Columbia Department of Labour. This man trained twelve of our employees as instructors by giving them an intensive one-week course. Similarity between the three courses was such that the instructors trained in the first one were very readily trained for instruction in the two succeeding courses."

Jan 1, 1952

By J. P. Gouvea, W. Geel

Resin bolting in South Africa has been developed and refined in underground coal mines (i.e., soft rock) since the late 1940s. The extension of resin bolting to hard rock mines started in 2003 and has required significant adaptations, challenging the status quo from both a supplier and applicator perspective. As far as resin bolting is concerned, the most affected aspect in coal mining and hard rock mining environments, is the rock drills or machinery used for installation. Hard rock mines mostly use hand-held airlegs with limited thrust, low torque, and rotation speed, relative to coal mine mechanised bolters. Resin bolt development for hard rock mines was, and still is today, predominantly focussed on compensating for the ‘shortfalls’ of using hand-held airlegs. At face value, hydro-powered rock drills, which are more powerful than traditional handheld equipment, provided hard rock mines with a means to attain more consistent and reliable resin bolt installations. This paper assesses the quality and performance of hydro-powered resin bolting at an intermediate to deep level platinum mine in South Africa and its potential contribution to rock-related instabilities when applied erroneously. The findings of this paper necessitate a revision of current quality control and quality assurance measures related to resin bolting for underground support.

Nov 24, 2025

A short overview of the research program of SveBeFo, Swedish Rock Engineering Research, which was founded in 1993 is first given. Then four recent and ongoing projects in rock blasting and explosives engineering are presented in greater detail: 1. Burn Equations for Commercial Explosives. 2. Blast Damage in Contour Blasting. 3. The Role of Gas Pressure in Pit Wall Damage. 4. Fragmentation of Aggregate Rock. The goal of the bum equation project is to be able to control the energy release from explosive charges to the desired part of the expansion curve of the reaction products under various rock conditions. SveBeFo's work has reached the stage where a burn equation for a lab emulsion has been established which can model the influence of charge diameter on the VOD and detonation front curvature in a cylindrical charge quite well. This work now continues with other emulsion recipes. In the blast damage project the goal is to develop techniques and recommendations on how to minimise the blast damage in construction blasting. The project has gained extensive practical knowledge from the blasting of more than 200 holes in a granite quarry under controlled conditions. The cracks in the rock surrounding the contour holes have been cut open and measured. The influence of factors like charge concentration, decoupling ratio, hole and charge size, VOD and time delay in initiation have been investigated. A simultaneous initiation of a group of contour holes with EDD detonators is quite superior to single hole blasts, even when they are timed as closely as 1 ms.

Jan 1, 1995

By C. N. Savage

An industrial minerals review involves an attempt to assemble field and statistical data which are obscure, elusive and incomplete. Often, when me statistical data are available, combining or lumping of commodity values conceals the value of specific items. Personal knowledge of the minerals known to occur in the area of concern, combined with whatever available published data may be compiled, together with careful use of several extrapolation methods, may yield an acceptable summary review of the industry. However, it is particularly hazardous to speculate on future trends and economic aspects because of the many unpredictable variables which may affect the industrial minerals business. Among these variables are the effects of diverse geological conditions, the impact of technological changes (including new uses for minerals not formerly considered industrial types), changing socio-economic factors (including growing environmental controversy), use of substitutes and even recycling of some of the industrial minerals (for example, building materials, lime, etc.). My main objectives are to reveal, as accurately as I can, the state of the in¬dustrial minerals situation, and the effects of possible future developments on this industry in Idaho. Where the words...industrial-tyke minerals, .are used in this discussion, reference is made to selected metallic and nonmetallic minerals and related materials, as well as rock (Table I). Industrial minerals known to be present in Idaho may be listed under general use categories as in Table 1. Some of these commodities are being marketed, have been marketed in the past, or occur in potentially marketable quantities. Mineral fuels are neither mentioned, nor are they considered important in Idaho. Based upon our present knowledge and lack of known, economically valuable occurrences of these commodities, they are considered insignificant (Idaho Bur. Mines and Geology, 1964). Information used for this study is from several sources. Most of the statisti¬cal information should be credited to the U.S. Bureau of Mines Minerals Yearbooks,

Jan 1, 1971

By J. E. Nesset, F. Rosenblum, J. A. Finch

"The self-heating of sulphides can be a major hazard in mining operations and concentrate handling, particularly during transportation and associated storage. Self-heating results from the oxidation of sulphide minerals and can vary from being insignificant to highly reactive and potentially hazardous to both humans and infrastructure. It is essential that there be a reliable test methodology that can measure and categorize a given sulphide material as to its self-heating potential. By their nature, sulphide ores and concentrates are complex and variable mineral mixtures making it difficult to predict their self-heating behaviour a-priori based on mineralogy or with a simple “snapshot” test. Furthermore, self-heating behaviour will depend on the state of oxidation of the sulphides as well as time, temperature and humidity. A review of available testing apparatuses and protocols that can be used to assess self-heating potential is presented. Each of these methodologies was examined in relation to its ability to measure and reliably predict the latent self-heating hazard of a sulphide material. Several of the methods were tested and compared to illustrate their strengths and weakness. The results indicated that a number of the test protocols may produce false negative indications of self-heating potential, constituting an obvious concern to the industry.INTRODUCTION Sulphides as well as other materials (coal, wood chips, hay, powdered milk, to name a few) that are stockpiled in an air atmosphere may undergo oxidation reactions which can result in the evolution of heat (Beever, 1984) (Hudak, 2002) (Blanchard, 2007). If the rate of heat generated exceeds the rate of heat dissipation, the stockpile temperature will rise, potentially leading to “hot spots” in the most reactive areas, and possibly even fires. The heat generation rate, the “self-heating” rate, depends on many factors such as the type and composition of material, particle size, moisture content, oxygen availability, ambient temperature and humidity, and of prime importance, the extend of prior oxidation, or more specifically, the presence of oxidation products. The desire of operators that mine, process or transport sulphide-bearing materials with a potential for self-heating is to have an accepted and reliable method for evaluating and quantifying the potential hazard of their material. The challenges are how to best measure the self-heating properties of given samples, and based on results, predict the behaviour of the bulk material over time and in-situ. Generally, when evaluating a given material one derives the self-heating characteristics of that sample at the time and under the conditions of testing, which will be referred to as a “snapshot test”. If that material is invariable, i.e. it will not change its response over time, then it may be considered to be a “predictive test”. However, if as a result of continuing oxidation or other changes, the material becomes more or less reactive with time, then a “snapshot test” is unreliable with respect to predictive ability."

Jan 1, 2014

"The business importance of water for mining companies is unequivocal as it may affect several aspects of mining projects ranging from the life-and-death license to operate to the imperative economic viability. It is thus no wonder that nearly all mining companies acknowledge water-related risks, issues and opportunities in their respective sustainability report. Somehow, this procedure has fostered the idea that water frugality could be the sustainable solution to several water-related issues. The regular exercise of water accounting should then follow as a key strategic requirement. Water accounting is defined as the application of a consistent and structured approach to identifying, measuring, recording and reporting information about water. However, several factors discussed herein have led to the fact that some water accounts are still produced using means (hardware and software) which undermatch the value actually associated with water. The resulting fuzziness about water usage could result in missed opportunities, suboptimal operations or even lead to environmental law violations. This paper subscribes to the distinctive perspective that, once underlying concepts and practical definitions have been standardized under a supported framework, such as the openly available Water Accounting Framework (WAF) published by the Minerals Council of Australia, most of the remaining water accounting issues may be boiled down to accuracy issues and, ultimately, to how much accuracy is valued by the stakeholders. Using the latest WAF document as a baseline for best practices of water accounting and, borrowing concepts from the fields of sensor network design in the process industries and best practices of metal accounting, this paper reviews some essential accuracy issues to be considered when designing or analyzing water accounting systems in mineral processing. The current paper also includes some elements for a promising attempt to include the value of information paradigm inside the water accounting best practices."

Jan 1, 2014

By B P. Wrench, M J. Gowan, P J. Chapman

Embankment dams constructed mainly of sand or non-plastic fine soils are susceptible to liquefaction, particularly in high-rainfall, high-seismicity environments where there is sufficient water to saturate the materials and sufficient energy from an earthquake to cause liquefaction. This paper shows the process adopted to review the stability of an existing cross-valley, centreline-raised cyclone tailings sand embankment dam.The study showed that two-dimensional stability analyses did not sufficiently capture the potential for instability, overestimating the depth of the critical failure surface. Instead, three-dimensional modelling was required to provide a reasonable representation. Post-liquefaction stability analyses carried out using the three-dimensional model indicated an adequate factor of safety (FoS). The FoS under seismic conditions was still considered to be a concern based on pseudostatic analyses (but noting the limitations of the analysis method).Earthquake-induced settlements were estimated using an empirical approach based on case history records (Swaisgood, 2003). The post-earthquake event settlement was estimated to be in the order of 600 mm, which is considered to be acceptable for the embankment, taking account of the proposed long-term freeboard of more than 8 m under operating conditions and 2 m under the probable maximum flood condition.CITATION:Chapman, P J, Wrench, B P and Gowan, M J, 2015. Review of static and seismic stability of a cross-valley sand tailings embankment in a high-rainfall, high-seismicity setting, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 163–172 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By M. C. Makepeace

"It is the objective of designed experiments to obtain more information for less material and process cost than can be obtained by traditional experimentation. In this paper, the fundamental concepts on which the statistical design of experiments is based are briefly re-viewed according to the following outline: The Experiment The Design The Analysis Two simple 2"" factorial experiments are presented as examples."

Jan 1, 1967

By S. W. Cavender

The analysis of the results of metallurgical experiments is often complicated by experimental errors and uncertainty, the complexity of the system being studied, and the confusion of correlation with causation. Consequently, comparative statistics are used to determine if a difference exists between the outcomes of tests, an estimate of this difference, and the precision of the estimate. This paper reviews the use of significance tests and confidence intervals for the comparison of results from two tests, the use of reference distributions, and blocking and randomization techniques to reduce unavoidable sources of variability. These techniques are demonstrated using plant and laboratory data.

Jan 1, 1993

By O. Dahl, B. Musuku, N. Schreithofer

Recovery of fine pentlandite is proving to be a challenging task in the Kevitsa sequential flotation operations, with over 60% of the nickel losses reporting into the -25μm size fraction. Since commissioning, the Kevitsa process has undergone major changes to address throughput and flotation performance. Major changes were implemented in the configuration of the milling and flotation circuits as well as in the operating conditions and reagent regime. Some of these changes improved nickel flotation while others deteriorated flotation performance. Most of the changes have had a direct impact on nickel flotation. This paper reviews the systematic analysis, laboratory testing and salient changes done to the process with special focus on the impact on the fine pentlandite flotation. Keywords: Blending, Flotation, Chalcopyrite, Pentlandite, Fines

Jan 1, 2020

By Madan M. Singh

It is estimated that through 1975, there were 1.69x109 m2 (418 000 acres) of urban land threatened by potential subsidence due to mining with a value of over $12 billion (19;3 dollars; USBM, 1979). With increased coal production to meet the energy needs of the nation, both these figures may be expected to increase. Hence greater attention to controlling surface damage due to subsidence is merited. In fact, the Surface `lining Control and Reclamation Act of 1977 (SMCRA) (Public Law 95-87) mandates that underground coal mining operators "adopt measures consistent with known technology in order to prevent subsidence causing material damage to the extent technologically and economically feasible, maximize mine stability, and maintain the value and reasonably foreseeable use of such surface lands, ..." The term "subsidence," as used in this paper, implies the total phenomenon of surface effects associated with the mining of minerals, and not only vertical displacement of the surface as is sometimes inferred in the literature.

Jan 1, 1984

By T. Chikande

"Falls of ground pose costly hazards to personnel and equipment and thus measures should be taken to prevent them. This study endeavours to improve the support systems used in geotechnically poor ground at a Zimbabwean platinum mine by analysing the status quo and recommending an effective support system. Various techniques were used to determine the quality of ground conditions, predict the rock mass behaviour, and to identify the appropriate rockbolt type. An analysis of the current ground control methods and their limitations was also undertaken.The results showed that the current support system and mining practices in poor ground need to be modified to improve safety and productivity. Stoping overbreak is influenced by poor ground conditions and the explosives currently used. The use of emulsion is recommended to replace ANFO. Redesigning of pillars is also recommended in poor ground conditions. An evaluation of the current roofbolt system indicated an opportunity for improvement. With new insight on the performance of the shorter length roofbolts currently in use, a new support system was recommended taking into consideration cost-benefit analysis. Barring down using pinch bars in poor ground was seen as a risky and time-consuming exercise, hence the use of mechanical scalers is recommended to achieve zero harm and to meet production targets. Smoothwall blasting is recommended in poor ground to minimize excavation damage. Other recommendations include the use of hydrological surveys to determine groundwater levels and implement corrective measures. Both empirical and numerical modelling approaches need to be utilized in determining the optimum support. IntroductionThe presence of geological discontinuities such as faults and joints weakens the rock mass. Adequate support is critical in achieving zero harm in underground mines. This paper reviews the current support systems used in poor ground conditions at a Zimbabwean platinum mine. The area of research is located on the Great Dyke of Zimbabwe. The mine exploits platinum group elements (PGEs) and base metals. It is shallow, having a maximum depth of less than 300 m. The Great Dyke is the second largest reserve of PGEs, following the South African Bushveld Complex (Oberthur et al., 2012). It is a linear layered intrusion that extends for about 550 km with a maximum width of 11 km (Prendergast, 1989). The generalized section of the Great Dyke is almost like a trumpet, comprising layers that dip towards the centre. The reef exploited at the mine, the Mineralised Sulphide Zone (MSZ), is located in the pyroxenite layer, which is hosted in the ultramafic sequence. The MSZ is a uniform layer about 2– 3.5 m thick, dipping at around 10–14° from surface outcrop towards the axis of the basin, and located between bronzite and websterite horizons. The visible disseminated sulphide mineralization shows a typical and consistent vertical distribution of platinum group metal (PGM) and base metal values. The research was undertaken to review the current support systems used in geotechnically poor ground conditions in a bid to improve both safety and productivity."

Jan 1, 2016

By K. Norris

The Amax Gold Guanaco mine is located in the Atacama Desert, approximately 260 km southeast of Antofagasta, Chile. The 6,000 tpd leach operation produces approximately 90,000 oz of gold, and 360,000 oz of silver per year. Production began in 1987, and the operation has been managed by Amax Gold since 1992. The mine has been plagued in the past by high operating costs and low production. Several significant changes have been made to the operations which have resulted in lower costs and higher operating efficiencies. A review of these changes is presented herein.

Jan 1, 1997

By HOWARND N. EAVENSON

THE year 1930 resembled the preceding one in the coal industry in continuing the era of falling prices and 'of the abandonment of unprofitable mines. Practically all coal prices fell, and in the steam sizes during the last half of the year this was particularly true, due to the small industrial demand. No new mines of any size were opened in the bituminous coal industry, but there was a steady increase in the number of cleaning plants of all kinds built in all fields. It is estimated that at least nine million tons per year were added to the previous total of washed coal. The largest washing plant started during the year was that of the Buckeye Coal Co., at Nemacolin, Pa., with a capacity of 650 tons per hour. Fig. 1 shows - the mixing-bin, conveyor galleries, washing-plant and skip hoist, and Fig. 2 the 120-ft. Dorr thickener for collecting the 48-mesh material from the wash water. Dryers are used for drying the steam coal product. The following statement by J. R. Campbell shows the effect of cleaning on Pittsburgh coal in Greene County: "With the advent of the 650-t.p.h. efficient washing plant in Greene County at the Nemacolin mine of the Buckeye Coal Co., it has undoubtedly been demonstrated that the potential coking-metallurgical coals of the county can be brought within the pale of the highest grade high-volatile coals for steel manufacture. A few months' operation indicates that 9% per cent ash in the raw coal can be easily reduced to under 7 per cent ash in the washed coal and the sulfur from 1.60 per cent in the run of mine to 1.20 per cent sulfur in the washed coal.

Jan 1, 1931

By Howard N. Eavenson

DURING the past year, as in the preceding ones, prices continued to fall, production to decrease, and more mines were closed. Much attention is being given by the industry to suggested plans for betterment of its position, and if the scheme recently brought out for consolidation of sales agencies into district agencies is loyally carried out, it cannot but help to improve conditions. The progress in the anthracite industry is shown in the report of its chairman, E. H. Suender; changes in coal preparation are outlined in the report of J. B. Morrow, chairman of Committee on Coal Preparation, while increased mechanization of the western mines is described by Eugene McAuliffe, chairman of the Committee on Machine and Strip Mining. In spite of the depression, interest in the Coal Division has been increasing, its meetings have been well attended, and its committees are active and have been doing excellent work.

Jan 1, 1932