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By David Norval

Water solidification of mattes, metals, alloys and certain slags with high metal entrainment has customarily not been practiced due to the belief that such processes are too dangerous and unproven in the Pyrometallurgical Industry. Slag granulation on the other hand is extensively applied, although in some cases crudely, with disastrous effects, as a result of not recognising the high heat capacities prevalent in slags. This paper will examine the most common air solidification processes and compare such processes with water solidification, mainly slag and matte granulation processes and design criteria for safe and reliable operation. Finally, purpose designed granulation and solidification processes will be discussed taking into account specific applications and the individual signatures of alloys and slags, emphasising that no slag, matte or alloy responds in similar fashion to a granulation practice.

Jan 1, 2006

By Dennis Dolinar

Improperly designed support systems have led to unplanned roof falls in longwall tailgates. To prevent such falls requires appropriate support and adequately designed support systems. The National Institute for Occupational Safety and Health (NIOSH) is currently developing a standing support design methodology based on the ground reaction curve. To design the support system with this methodology requires a quantitative assessment of the ground and support interaction, which is developed from instrumented test sites installed in longwall tailgates. To compliment and expand the field data results and to optimize the support design, numerical modeling is also conducted. The models are calibrated from the test site data. In the present study, data was obtained from a longwall tailgate in the Illinois basin. The test site was located in the Herrin No. 6 coal seam at a depth of 500 ft. At the site, the immediate roof was a weak shale overlain by a competent limestone. Above the limestone, sandstone formed the intermediate roof. The floor consisted of a weak underclay. In the study, the performance and interaction with the surrounding rock mass of two different standing supports, an engineered crib and a conventional 4-point wood crib were monitored. The two cribs have similar load-displacement characteristics at least through 6 in of displacement. Beyond 6 in, the engineered crib becomes unstable and begins to strain soften and shed load. The measurements and developed ground reaction curves indicated that the tailgate at the mine was a low convergence environment until well inby the face. Because the convergence was well below their capacity, both supports provide more than adequate levels of support to the tailgate. Significant convergence and support loading did not occur until 90 to 100 ft inby the face. The results of this study were also compared with results from similar studies conducted in the Pittsburgh seam to further advance the development of the ?ground reaction curve? based support system design.

Jan 1, 2009

By H Matsuno, N Oyama, T Yamamoto, K Nakajima, Y Iwami, N Saito

Recently, the quality of sinter feed ore used in sintering process has deteriorated. In particular, Fe has decreased and gangue component has increased in the sinter feed ore. Increase of gangue is not only the factor to influence sinter qualities, but also the factor to increase coke ratio in the blast furnace operation as the increase of slag ratio. Therefore, to cope with the deterioration of iron ore qualities, studies on alternative iron ore resources and development of its utilisation technology have been required.In that kind of new iron ore resources, authors focus on high-grade magnetite fine. High-grade magnetite fine decreases sinter productivity by the decrease of permeability of sintering bed. Therefore a new study for using large amount of magnetite fine is required. In the past, there are some studies about the effect of mixing ratio and size of magnetite fine on productivity and quality, but there are few studies about magnetite fine segregation in charging.In this research, the melting behaviour and interfacial reaction calcium-ferrite, which has important role as bonding agent among iron ores, melts into hematite substrate and magnetite substrate was studied. As the results, it was defined that upper segregation of high-grade magnetite fine is suitable for productivity of sintered ore. Based on this knowledge, the control method of high-grade magnetite fine segregation by magnetic force at charging was studied with DEM (discrete element method) and its verification experiments for magnetic segregation control was conducted in the laboratory.CITATION:Iwami, Y, Yamamoto, T, Oyama, N, Matsuno, H, Saito, N and Nakajima, K, 2017. Improvement of sinter productivity by control of magnetite ore segregation in sintering bed, in Proceedings Iron Ore 2017, pp 61–68 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By C. Kennedy, S. Jensen

Traditionally, mineral processing plants are designed to achieve the highest recovery of valuable material with limited regard for the cost of managing waste products-both solid and water components. As an industry, we are confronting ever more stringent environmental standards and lower grade deposits requiring more intensive processing. The most profitable processing route can, in fact, lead to costly issues downstream. Issues or risks associated with waste management include water treatment and handling and storage of potentially acid generating material. The capital and operating costs of dealing with these issues are significant and should be considered as a consequence of plant design and optimisation. The authors of this paper are involved with a number of projects where process operation changes offer opportunities to mitigate risks associated with water and waste management. Examples of these changes will be discussed along with the estimated benefits to the value of the project and reduction of long-term environmental risks. Process changes include 1) the application of in-plant water treatment as opposed to dealing with the entire tailings management facility and 2) the potential to reduce metal leaching and acid rock drainage through the preferential liberation of carbonate minerals in the grinding process.

Jan 1, 2014

By Graham Davey

"Low speed stirred milling has been employed for many years in the metalliferous and industrial minerals industries. High speed stirred milling is a relatively new method of grinding in the metalliferous process industries. However it has been it has been in wide spread use in the industrial mineral field for over 30 years for various minerals. Many existing metallurgical operations are looking to maximize economic return from existing deposits, requiring new thinking and technologies. By combining low speed and high-speed milling fine and ultrafine grinding efficiency and operating costs can be improved.The correct selection of different fine grinding technologies is covered, when each mill is applicable and when a combination of the VERTIMILL® Grinding Mill and SMD provides the best economic solution.INTRODUCTIONUltra-fine grinding of minerals has been in wide spread use in the industrial mineral field for over 30 years. Within the last 10 years the metalliferous industry has shown interest in the ability to produce ultrafine particles, as chemical, physio-chemical and physical separation processes have advanced to be able to treat ultrafine metalliferous particles. Also as the primary mineral deposits, around the world are depleted, new more difficult deposits must be mined. Existing operations are also looking to maximize economic return from existing deposits, requiring new thinking and technologies.The traditional approach for gold containing refractory material has been to liberate the locked gold by chemically destroying the pyrite through oxidation. Roasting, pressure oxidation, and bacterial oxidation all employ various degrees of temperature, pressure and catalysis to react the pyrite with oxygen to produce iron oxide and sulfur by-products. However all of these methods are economically impacted due to specific operational added requirements and emissions controls. Pressure and bacterial oxidation have very high capital and operating costs."

Jan 1, 2006

By C. M. Diaz, S. W. Marcuson

In the late 19th century, the discovery of rich nickel-copper sulfide ore bodies in Sudbury and the need for tonnage quantities of the metal to be used in nickel steel armor provided the foundation for establishing the Canadian nickel industry. For almost 50 years, International Nickel was the key player. In 1930, Falconbridge Nickel entered the field. These two companies remain the key Canadian nickel producers. This paper discusses the factors that have influenced the evolution of nickel smelting processes. The initial Sudbury ore smelting and nickel copper separation technologies were imported from abroad. It was only in 1937 that International Nickel established a process research laboratory in Copper Cliff The explosive post WW II industrial development created a strong demand for a broader variety of nickel products. For both International Nickel and Falconbridge, R&D became an essential business tool to succeed in the new market scenery. In the last few decades, new technologies were developed and commercialized to respond to the raising cost of energy, society pressing environmental concerns, the advent of nickel laterites as an important source of new metal, the incorporation of new nickel producers to the market, and, therefore, the need to increase productivity. Canada thus became an important exporter of technology. In this paper, the authors review this history with the objective of highlighting the forces that have triggered the most important changes in Canadian nickel smelting.

Jan 1, 2005

By O. C. Blade

This report on the properties of motor fuels sold through service stations-in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Deparment of the Interior. It presents analytical data for 4,397 samples, representing the products of 130 companies. The samples were collected during December 1952 and January and February 1953. As in previous surveys, the gasolines covered by this survey include those from both large and small suppliers. The data were obtained by laboratories of various refiners, motor manufacturers, and chemical companies and submitted to the Bureau of Mines for compilation. A list of the National Motor-Gasoline Survey reports published during the past ten years is given on page 5.

Jan 1, 1953

By P. A. Plunkert, D. E. Morse, L. McCartan, S. F. Sibley

The average annual growth rate of real gross domes-tic product (GDP) from the third quarter of 2001through the second quarter of 2003 in the United States was about 2.6 percent. GDP growth rates in the third and fourth quarters of 2003 were about 8 percent and 4 percent, respectively. Many other indicators reflected a rebounding U.S. economy — rising consumer confidence, higher retail sales, greater industrial production and more housing starts. Inflation also reached a 38-year low in 2003. The upward trends in many sectors of the U.S. economy in 2003, however, were shared by few of the mineral materials industries. Annual output declined inmost non fuel mining and mineral processing industries, although there was an upward turn toward yearend as prices began to increase (Table 1).

Jan 1, 2004

By L. R. Burdick, J. F. Barkley

"There is a general conceit in the coal trade that the moisture- and ash-free B.t.u. of coal from the same seam, and surely from the same mine,is substantially a constant; that calculation of the moisture- and ash-free B.t.u. value from the proximate analysis and B.t.u. determined in the laboratory will reveal whether a coal came from a given area or seam; and that, having this constant, the B.t.u. value of a coal sample can be calculated fairly closely upon a dry or as-received basis from the moisture and ash values of its proximate analysis.To illustrate with a simple example;"

Jun 1, 1941

By Aditya Rana, A. K. Mishra, M. M. Singh, N. K. Bhagat

Many cases of derailments, train accidents and traffic interruptions due to the slope failure and rockfall have been reported in the past on Konkan Railway trackline because of unstable rock slopes. The authorities installed stability enhancement measures such as wire netting, rock bolting and shotcreting which were found insufficient. The failed geotechnical measures prompted authorities to excavate the unstable slopes. Rock blasting is generally not preferred for the excavation of slopes along the transportation route. Stabilisation and widening of slopes by blasting need closure of the route for a considerable time. Discontinuing traffic on Konkan Railway route was undesirable as it connects two important port cities Mumbai and Mangalore. The paper presents an innovative directional controlled blasting (DCB) technique for excavating three unstable slopes (i.e. cuttings) in hilly terrain without disturbing the traffic. New empirical formulae for small geometry blasting to estimate burden and throw have been developed. A unique sequence of firing and excavation with powder factor varying between 0.04 and 0.39 kg/m3 irrespective of the actual free face was used for rock blasting. The process controlled the throw of blasted material over the track and resulted in a smooth and stable wall. The slope angle has been changed from 80 to 82° to 45–47° and probability of wedge, planar and toppling failures was eliminated. About 100 such accident-prone slopes (52 km cumulative length, 7% of total route) situated at discrete locations along Konkan Railway route were stabilised using the technique. No incident of rockfall and slope failures along these slopes has been observed after the stabilisation.

By Leo A. Schrider

A prediction for oil recovery from a pilot waterflood in the Kane oil- field, located in Elk, Forest, and McKean Counties, Pa., was made and compared to actual field performance. Water-injection and production histories, well logs, other field data, and results from laboratory tests of core material were used in this analysis. Performance of the pilot waterflood, initiated in January 1963, was predicted using a modified Craig, Geffen, and Morse calculation technique. Maximum recovery from this low permeable, preferentially oil-wet formation was predicted to be about 22,500 barrels of oil after 300,000 barrels of water had been injected into the pilot waterflood area. After additional field data were collected it became necessary to reevaluate the pilot waterflood area. The gas saturation prior to the waterflood was estimated to have been 20 percent, based on an assumption regarding the required volume of water injected to initiate oil production. In view of the actual field performance, a gas saturation of 13 percent is indicated. When this gas saturation and the method originally proposed by Craig and others are used) the predicted results are more representative. In December 1965, field performance was further analyzed using a hyperbolic-decline curve as presented by Arps. Based upon this evaluation method, the pilot water flood in the Kane sand should produce 37,000 to 42,000 barrels of oil with the injection of 300,000 barrels of water into the pattern. By continuing this secondary-recovery project to a reasonable economic limit, ultimate oil recovery may be as much as 50,000 to 55,000 barrels, or 129 to 142 barrels per acre-foot from 36.5 acres.

Jan 1, 1967

By H. H. Fairfield

THE production and inspection of the materials of war involves thousands of observations. Logical action is generally based on the interpretation of many observations. The success of such action depends upon the accuracy of the observations and the soundness of the interpretation placed upon them. There are countless instances where the observer 'sees but perceives not'; that is, the significance of a group of observations is lost, due either to faulty interpretation or to no interpretation at all being placed on the results. This condition is being partly corrected in the United Kingdom and the United States (1) by the promotion of certain principles by Ordnance officials. The term Quality Control has been adopted to describe a system of studying and controlling industrial products by methods of handling observations. In these pages an attempt is made to outline in a non-technical manner some of the ideas used in the handling of observations. Of course the authenticity of the observations determines the worth of any decisions based on them. No matter how brilliant is the theory built on unreliable sampling, it is usually of little practical value. n some fields it is almost impossible to obtain observations free from bias. Let us suppose that observers of speed in miles per hour were available for judgment: (a) a bystander, (b) a motorcycle policeman, and (c) a motorist accused of speeding. The bystander might be unbiased but probably would be very inaccurate. The motorist is usually biased on the low side. The policeman is the only qualified observer and, if over-zealous, he might be biased on the high side. Conclusions drawn from large numbers of biased observations naturally would be of little value.

Jan 1, 1943

By Éder Domingos Oliveira, Carlos Antonio Morais, Ruberlan Gomes Silva

The objective of this study is to assess the impact of different reagents, such as limestone, lime, magnesium oxide, and sodium hydroxide, in experiments carried out in the single purification step and in two consecutive purification steps by raising the pH of a rare earth sulfuric liquor with the aim to remove or reduce the impurity concentrations in the rare earth sulfuric liquor. The choice for the best purification condition was made based on the minimum loss of rare earth elements (REEs), reagent consumption, and residue generation. The exploratory experiments show that it takes place in the two consecutive purification steps, the first one consists in dosing the limestone pulp until it reaches a pH of 3.5 followed by an addition of a lime pulp reaching a pH of 5.0. Under this condition, the results were a total removal of Fe3+, PO4 3− , and Th4+ ions and a reduction of 99%, 87%, and 37% w/w in the Al3+, UO2 2+, and SO4 2− concentrations, respectively, in the purified rare earth liquor. Furthermore, the lowest REE losses (8.3% w/w) and reagent consumption (4.3 kg/m3 ) and also a low residue generation (7.5 kg/m3 ) were observed in this condition. Despite reaching similar results regarding impurity removal, the experiments done with the addition of limestone, lime, magnesium oxide pulps, and sodium hydroxide solution in the single purification step, where the pH was raised to 5.0, presented higher REE losses (64.9%, 42.5%, 44.8%, and 60.9% w/w, respectively) and a higher residue generation (43.2, 25.1, 11.1, and 13.6 kg/m3 , respectively). This occurred due to the co-precipitation of salts containing rare earth elements in their composition. The experiments conducted with limestone, lime, and MgO resulted in a higher consumption of reagents, while the same result was observed when NaOH was used (4.3 kg/m3 ). In the experiments carried out with the addition of magnesium oxide and sodium hydroxide, the respective purified rare earth liquors presented a high concentration of magnesium, sulfate, or sodium, which could impact the quality of the marketable rare earth salts, whereas the salts obtained under the best condition observed in this study seem to be amenable for use as raw material in an attempt to obtain rare earth products with an acceptable chemical quality.

By R. Yang

This paper presents a kinematic approach for blast modeling with examples of blast models that were developed previously. A kinematic approach was applied successfully in developing blasting models that can simulate all blast design parameters for field applications. Several applied blasting models have been developed and applied widely in the world. A kinematic approach to blast modeling refers to using measurements of kinematic quantities such as the velocity, strain, or displacement and well-established assumptions to model blasting phenomena, rather than being restricted to use first principal of physics, such as, the stress- and material-constitutive relations. The kinematic quantities are easy to measure in the field. Due to the complexity and inhomogeneity of rock mass properties, using first principles of physics, many parameters of rock and explosive properties must be involved, which are hard or impossible to quantify. This creates a major impediment when trying to simulate the total process of blasting based upon first principles of physics. The 3D kinematic model for muckpile formation was developed and applied to open pit blasts. The multiple blasthole fragmentation model developed during recent years has been applied successfully to many mine sites around the globe. These models are typical examples of blast modeling using the kinematic approach, which enables the models to catch major trends of the blasting process and explicitly simulate full blast design parameters and complex geometries. Blast modeling using the kinematic approach results in easy model calibration and validation against field measurements and effective applications to practical problems. Using kinematic models of the muckpile formation and the multiple blasthole fragmentation model, this paper demonstrates the merits of the kinematic approach for blast modeling. New developments of the models were also presented in the paper, which illustrate the potential of the kinematic modelling approach.

Mar 2, 2022

By Peter B. Lilly

Thank you, Syd, for the kind introduction and for inviting me to give the Keynote Address at this very prestigious gathering of some of the finest intellect and talent in the domestic and international coal industry. CONSOL Energy has been a part of this conference for its entire 24-year existence. We have presented 27 papers over that time. CONSOL employees have also been members of the planning committee for the conference, and we have been pleased to support the event both financially and with many participants. So I am honored to be here with all of you this morning, especially during such a positive period for coal. You can just feel the enthusiasm in this room for our industry, and for this conference. I can tell you, there?s also a lot of enthusiasm and excitement in CONSOL Energy?s boardroom. And our enthusiasm is mirrored on Wall Street. But there remains an ironic twist to all of this attention. Even when times are good, the coal industry seems to go largely unnoticed by the mainstream. Outside of West Virginia and other coal-producing regions, the industry still seems to lack influence and support, at least here in America. As an example, last month, an ABC News crew visited our Blacksville 2 Mine, near here, to do a feature story on increased employment in the coal industry.

Jan 1, 2006

By T. M. Barczak

Longwall tailgates in coal mines are often subject to severe mining induced loading and deformation. Innovative tailgate supports have been developed over the years to provide safe and economical access and a ventilation pathway at the tailgate. The support capacity and yield capabilities of the supports need to be matched to the loading imposed by the surrounding rock mass. The ground response curve can be used to represent the rock mass response to mining and its effect on support systems. The FLAC finite difference code was used to supplement field results by simulating a longwall tailgate and the associated ground response. The ground response curve is developed by modeling tailgate excavations with different internal support pressures and recording the resulting convergence. Ground response curves are developed for two typical longwalls operating in the Pittsburgh seam with weak and strong immediate roof. An additional model is presented in which the effect of weak overburden strata is simulated. The ground response is shown to be significantly affected by the strength of the immediate roof as well as the main roof. The importance of yield capacity of standing support is demonstrated. Gob height and compaction are found to affect the amount of convergence in the tailgate. The potential exists to develop site specific tailgate design curves by combining model results with field observations.

By R. H. Sergent

The interest in using halogens for extracting precious metals from ores has increased due to changes In ore characteristics, environmental concerns and regulations. The rediscovery of halogen leaching capability has been the topic of these and other writers1-30. Much work has been done on the performance of bromine, chlorine and iodine5-29. Of these, bromine and chlorine look most promising. Iodine is quite expensive and sometimes forms an Insoluble film on a precious metal surface22,23. Little experimental work has been published on the relative performance of bromine versus chlorine. The Pourbaix diagrams for the halide leach system (see Fig. 1-4) Indicates a significant stability advantage for bromine In forming complex ions with gold. This should result In greater extraction of gold under similar leach conditions and Is evaluated In this work. The regeneration of halogen from a spent leech solution is a critical requirement for an environmentally acceptable halogen leach process. Bromide can be oxidized In-situ to bromine ~ adding chlorine or ozone2,31. Bromide like chloride can be oxidized In an electrochemical cell to produce halogen on demand 13,15,17. Bromine clearly offers a number of possible regeneration pathways. This work strives to compare the relative ability of chlorine and bromine to extract gold from partially and fully oxidized ores. A commercially pressure oxidized sample was evaluated under a number of experimental conditions. The autoclave feed ore from the same mill was also evaluated after complete oxidation In a laboratory autoclave.

Jan 1, 1993

By Carlos de F. Gontijo

The flotation of quartz particles was studied over the particle size range from 0.5 µm to 1000 µm and for advancing water contact angles between 0º and 83º. Flotation was performed in a column and in a Rushton turbine cell. Particle contact angle threshold values, below which the particles could not be floated, were identified for the particle size range 0.5~1000 µm, under different hydrodynamic conditions. The flotation response of the particles, either in a column or in a mechanically agitated cell with a similar bubble size, was comparable. Turbulence plays a role, as does bubble-particle aggregate velocity and bubble size. The stability of the bubble-particle aggregate controls the maximum floatable particle size of coarse particles. For fine particles, the flotation limit is dictated by the energy required to rupture the intervening liquid film between the particle and bubble. Flotation of very fine and large particles is facilitated with small bubbles and high contact angles. These results greatly extend our earlier observations and theoretical predictions.

Jan 1, 2014

By Lluis F. Fontboté

The paper point out the deposits about the carbonate-hosted San Gregorio Colquijirca, as products of an epithermal high sulfidation system. Field, geochemical, and geochronological evidences suggest that the different ore types of the Colquijirca District are caused by a pulsed high sulfidation system subsequent to the emplacement of a diatreme volcanic complex. The first stage formed disseminated Au±Ag mineralization in areas affected by vuggy quartz alteration at Marcapunta. During a second stage, base metal mineralization replaced Eocene carbonate sediments from the Marcapunta diatreme to 2.5 km more to the north. San Gregorio and Colquijirca are to our knowledge the first "carbonate-hosted epithermal Zn-Pb high sulfidation deposit" recognized as such. The correct recognition of this ore type opens new exploration possibilities for base metal in high sulfidation systems affecting carbonate rocks.

Apr 24, 2001

By D. Orynbassar, N. Madani

This work addresses the problem of geostatistical simulation of cross-correlated variables by factorization approaches in the case when the sampling pattern is unequal. A solution is presented, based on a Co-Gibbs sampler algorithm, by which the missing values can be imputed. In this algorithm, a heterotopic simple cokriging approach is introduced to take into account the cross-dependency of the undersampled variable with the secondary variable that is more available over the entire region. A real gold deposit is employed to test the algorithm. The imputation results are compared with other Gibbs sampler techniques for which simple cokriging and simple kriging are used. The results show that heterotopic simple cokriging outperforms the other two techniques. The imputed values are then employed for the purpose of resource estimation by using principal component analysis (PCA) as a factorization technique, and the output compared with traditional factorization approaches where the heterotopic part of the data is removed. Comparison of the results of these two techniques shows that the latter leads to substantial losses of important information in the case of an unequal sampling pattern, while the former is capable of reproducing better recovery functions.

Aug 1, 2021