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By A. W. Deurbrouck, W. W. Agey

Introduction The modern wet concentrating table is a rectangular or rhomboid shaped normally rimed-deck operated in essentially a horizontal plane (Fig. 23). A drive mechanism imparts a differential motion to the deck along its long axis while water flows by gravity along the short axis. Tables are currently employed for processing large tonnages of coal and lesser tonnages of barite, beach sands, chrome, glass sand, garnet, iron, manganese, mica, phosphate, potash, tantalum, tin, tita-

Jan 1, 1985

By Parris A. Lyew-Ayee

This paper is the first preliminary report on the bauxites and terra rossas of the Caribbean. It concentrates on the islands of the Greater Antilles, and for reference purposes the Yucatan Penin- sula is included. At this point, observations made in Jamaica, Haiti, and the Dominican Republic are compared with reported information on Puerto Rico, the Bahamas, Cuba, the Cayman Islands, and the Yucatan Peninsula with regard to occurrence, as well as physical, chemical, and mineralogical composition. From this, an attempt is made at classifying the types of bauxites in the Caribbean, indicating the best reserves estimates, and the process ability of these bauxites. Some suggestions are also provided to fuel the controversy over the likely source material(s) or origin of the Caribbean bauxites.

Jan 1, 1984

By Brij M. Moudgil

Separation of oil shale from waste material or into high grade and low grade fractions can have a major influence on the economics of the surface (ex-situ) retorting process. Different components of shale rock vary significantly in physical and surface chemical properties such as specific gravity, color, water wettability etc. Various techniques which utilize the difference in one or more of the above propartis have been proposed to preconcentrate the oil shale before retorting. A discussion of the techniques proposed such as gravity separation, sorting and froth flotation is presented.

Jan 1, 1982

By D. W. Frommer

Processing nonmagnetic taconites by selective flocculation-desliming and flotation requires large volumes of water. If impounded without treatment these off-process waters require excessively large areas for containment. To discharge the waste water into natural waterways would contribute to stream pollution and likely would not be permitted. In Bureau of Mines experiments conducted in the Twin Cities Metallurgy Research Center&apos;s 900-lb/hr pilot plant, approximately 85 percent of water requirements for the flotation-based treatment of a Michigan nonmagnetic taconite were met by reclaimed water. Water reclamation of the off-process streams from flotation was accomplished by controlled additions of lime, sodium carbonate, and a synthetic flocculant to reduce turbidities to <1,000 ppm equivalent Si02, while maintaining a Ca(II) content of 516 ppm in the finished effluent. Flotation concentrates of good quality were obtained using the reclaimed water. The cost of chemicals used in water reclamation was approximately equal to the savings in flotation reagents attributed to recycling of the water.

Jan 1, 1970

By B. Markovic

Performance of mineral filler particles in ceramic applications can be enhanced markedly by adsorbing polymers of optimum molecular structure and dosage. In a recent work by Chen and Somasundaran (1997), a novel scheme of controlled polymer adsorption was used to produce nanocomposites of unique core-shell designs. Towards this purpose, adsorption and desorption behavior of selected polyacrylic acids (PAA) on three minerals; alumina, titania, and silicon carbide, was examined as a function of relevant parameters. Adsorption of P AA was found to depend on polymer molecular weight, pH, as well as solids loading. Specifically, the adsorption density was found to increase with increase in polymer molecular weight for non-porous alumina while it was found to decrease in the case of porous alumina. This is attributed to the inaccessibility of the pores to the larger polymers. An unexpected finding was the change in the adsorption density of PAA with solids loadings. PAA adsorbs on silicon carbide only at low pH values when the particles have very low surface charge suggesting that the adsorption in this case is controlled by electrostatic forces. Using polyacrylic acid as bridging agent between the alumina fillers (core) and nanosize alumina or titania particles (shells), controlled layer by layer deposition of nanoparticle on the core particle surface could be obtained.

Jan 1, 1997

By M. T. Ityokumbul

Flotation columns and their variations are increasingly replacing conventional cells in mineral-processing circuits. While the operational characteristics of columns differ from those of conventional cells, the same scale-up methodologies are being employed. This practice may be attributed to a poor understanding of the factors that control throughput. The use of tall flotation columns is frequently justified because of the need for an increased particle residence time. However, it is shown that longer particle residence times alone do not translate into increased recoveries. In this paper, throughput data from several industrial flotation-column installations is presented. Also, an attempt is made at using dimensional analysis to provide a scale-up methodology for the factors controlling column throughput.

Jan 1, 1997

By William H. Meadows

This information describes the ventilating and methane gas testing procedures utilized during the raising of a mine shaft using a Robbins 81-R drill. An overview of the raise boring process is presented to illustrate the ventilating and gas testing procedures. A mine shaft project, 4.88 m (16 ft) in diameter and approximately 457.2 m (1500 ft) in length, will be the focal point of the presentation, with reference to similar projects for additional comments on variations in procedure.

Jan 1, 1980

By John D. Morgan

The United States is the world&apos;s most productive nation and its citizens enjoy one of the highest material standards of living of any people in the world. Materials and energy are the lifeblood of any industrialized economy. Annually the United States uses over 4 billion tons of mineral materials and fuels, or 40,000 pounds per person as detailed in Figure 1. Domestic processed materials of mineral origin and energy are valued at more than $150 billion annually, and they are derived largely from domestic sources, supplemented by imports, as detailed in Figure 2. In recent years the superior productivity of the United States has also enabled it to give food and manufactured articles to many other less fortunate nations and peoples of the earth. What then is our concern with materials at this time? Seeing the burgeoning increases in our mineral demand: from 2 billion tons in 1950, to over 4 billion tons today, and projected to 11 billion tons by 2000 - we are getting questions concerning our ability to continue to increase production sufficiently for the future.

Jan 1, 1974

By João F. C. L. Costa, Vanessa C. Koppe, Clayton V. Deutsch, Marcel A. A. Bassani, Pedro H. A. Campos

Blending inevitably occurs to some degree during mining and mineral processing operations. Traditional mine scheduling assumes that all variables average linearly, which allows the calculation of the blended material properties as a linear weighted average. However, metallurgical properties such as metal recovery and Bond Work Index (BWI) are known to average nonlinearly. The nonlinear properties of the blended material can be calculated using nonlinear blending models. A simulated annealing algorithm is developed and applied to a short‐term mining face optimization problem to maximize the total metal recovered considering nonlinear blending. Compared to a standard schedule plan, the optimized one shows relevant improvements in synergistic and antagonistic blending behaviors.

Jun 25, 2023

By K. Hanumantha Rao, K. S. E. Forssberg, H. R. Manouchehri

This paper summarizes the practical considerations of the various electrical separation methods used in mineral processing. The effective factors related to mineral characteristics and equipment attributes are described and analyzed with reference to conventional industrial applications of the electrical methods. Some new aspects of electrical methods application and their potential for mineral beneficiation, apart from the mineral systems that have been successfully beneficiated, are also presented. In addition, wet dielectric separation, which now appears to be promising, is briefly cited.

Jan 1, 2000

By William G. Pariseau

The purpose of this paper is to present a design procedure for the quantitative estimation of support load requirements in underground mines. Emphasis is upon the basic features of support behavior common to a large variety of support systems-bolts, timber sets, stope fill, steel arches, concrete liners and so forth. A strong reliance is placed upon fundamental principles and modern computing techniques for their quantitative implementation. Example problems illustrate the approach. Where artificial support is required, the ground in the vicinity of the face usually stands unsupported long enough for the support to be installed. At the time of installation, the load transferred to the support from the adjacent rock is essentially zero, although in some cases there may be an initial set load, for example, from timber blocking. With the passage of time and advance of the face, ground motion loads the supports. If the support system is properly designed, then the additional loading poses no threat to the safety and productivity of operations. If not, then difficulties may arise including high maintenance costs, hazardous work conditions and reduced productivity. Of course, over-design can be equally wasteful. Quantitative estimation of support loads is therefore essential to overall efficiency in mining.

Jan 1, 1975

By Roe-Hoan Yoon

Froth flotation is widely used for separating particulate materials from one another in aqueous media. The basis of this important separation process is to control the hydrophobicity of particles. However, it is difficult to predict the kinetics of flotation based on contact angle (?), which is a thermodynamic property. A solution to this difficulty would be to develop a relationship between ? and the gradient of the hydrophobic forces across the solid-liquid and bubble-liquid interfaces. Such information can be obtained using the surface force apparatus (SFA), the atomic force microscope (AFM), and the thin film balance (TFB). The present communication reviews the results of the measurements conducted using these methods, and offers a methodology for deriving a rate equation for bubble-particle interactions

Jan 1, 1999

By Todd S. Harris

Industrial minerals or non-metallic minerals are loosely used terms applied to a diverse assortment of materials which, in many cases, have nothing more in common other than the fact that they are neither metals nor fuel minerals. To help bring order to this otherwise random assortment of minerals, we have grouped these materials into two main categories; chemical and physical minerals, and nine sub-categories based on end-use applications as shown in Table 1. Chemical minerals are products which are principally used for the specific chemical elements they contain, whereas physical minerals are products which are used to meet specific performance specifications. The latter part of the 1970?s, in particular 1978, were considered peak years in terms of production and sales for many industries, By using 1978 as a base year, we can evaluate wherethese markets stand today after the recession of the early 1980&apos;s and the recovery which began several years ago. From this historical overview and appraisal of the current situation, various assumptions can be drawn as to which markets are expected to perform well into the 1990&apos;s.

Jan 1, 1987

By J. O. Craig Imrie

Mine operations are being squeezed to do more with less. This is not new. But, where do mine operators turn for the next stage of improvement? Many have waged strong wars on the cost reduction front and cut back staff to the bone, yet need more improvement to remain competitive. This paper will outline an approach which a few leading operators have taken. Following the footsteps of manufacturing's view of supply chain management and basic quality management they are reaping the benefits of taking a more holistic process view of their operation. This paper presents summaries of three companies' approaches and the impact which is being felt on the bottom line.

Jan 1, 1999

By R. F. Harig

Designing an underground nuclear waste repository is a complex process. Although many decisions are involved before the design is complete, the first three--what the target horizon is, what the underground boundary is, and where the entry point will be located--are important because they establish the basis for the entire repository design. Even more important than these decisions, however, is the data on which the decisions are based. Because the current data are limited, an aggressive data gathering program is needed during the next design phase to augment information about the intricate interplay among all facets of the repository design and the geologic medium in which the proposed repository is to be developed. Although unique to modern engineering enterprises, the challenges involved in designing a repository in the unsaturated zone are within current technology and engineering practices.

Jan 1, 1991

By David R. Maneval

In 1956 the Legislature of the Commonwealth of Pennsylvania created a "Coal Research Board" in the Department of Mines and Mineral Industries. Over the years through amendments to the original legislation, the scope of authority for research has been expanded from the narrow area of improving and increasing the utilization of coal to covering all aspects of coal technology and any other area of interest which would be of value to the coal industry. In January of 1964, the Board commenced a vigorous program using appropriated funds and funds donated by the coal industry to finance a research program devoted to seeking solutions to the mine drainage problem. A review of published literature on the treatment of mine drainage indicated that much work done up to that point in time concerned only the mechanism of mine drainage formation and theoretical chemistry. Very few applied, developmental, or engineering studies had been devoted to finding practical solutions to the problem of polluted waters being discharged from active or abandoned mines. Projects were therefore undertaken on a wide variety of more utilitarian approaches. This paper will discuss briefly some of the pollution abatement approaches which have been funded by the Coal Research Board of this State, and will describe in some detail a multistage flash evaporator treatment plant now under construction.

Jan 1, 1970

By Charles D. Litton

Introduction The successful performance of a mine-wide fire detection system depends upon its ability to detect the presence of a fire rapidly and reliably. It should be sufficiently rapid so that there remains enough time to either safely evacuate a mine or successfully extinguish and control the fire or both. It should be reliable so that false alarms are minimized without sacrificing sensitivity or time response. Systems should also be durable enough to withstand the mine environment over long periods of time while maintaining a high degree of re1iability. Maintenance and calibration of the system should be simp1 e and not require the expenditure of excessive time and manpower to keep it operational. Sensitivity, reliability, and durability of mine fire sensors and their electronic support systems have been the subject of significant Bureau research within recent years. The bulk of this type of information, along with the reports from which the remainder of this paper is derived, can be found in the Bibliography. It suffices to say that there exist commercially available systems for use in mines. This paper addresses a strategy for the use of such sensors and systems. Many factors influence the design of a mine-wide fire detection system, such as the potential sources and modes of ignition, the types of combustibles involved and the quantities avai1able for fire growth and flame spread. Mine air ventilation influences the growth and spread of a fire and also serves to transport the products-of-combustion to other areas of a mine remote from the fire. Fire sensor alarm thresholds place limits on the sizes of fires that can be detected. The time to respond to a detected fire, either in terms of evacuation or control and extinguishment, place additional time constraints on the design of fire detection systems. These factors interact with each other, often in complex ways, and it is the definition and understanding of these factors and their interactions that hold the key to the design of adequate and re1iable fire detection systems. Our level of understanding of the problem has increased dramatically within recent years and it is the intent of this paper to discuss the progress that has been made and how the information can best be used to improve the level of fire detection in underground mines.

Jan 1, 1986

By D. L. Slyter

Coeur d'Alene Mines Corporation's Thunder Mountain project in Valley County, Idaho, is one of the most remote active mining operations in the US. High altitude, heavy snows, and proximity to wilderness complicate operations in this environmentally sensitive area. Mining is conducted by conventional open pit techniques while processing utilizes on-off heap leaching and Merrill-Crowe zinc precipitation. The project is one of a few similar operations which detoxify the leached ore prior to its removal from the leach pads. Both leaching and neutralizing ( detoxifying) circuits are closed and independent loops. After leaching, alkaline chlorine solutions destroy residual cyanide in the heaps. Calcium hypochlorite solution for the cyanide destruction is prepared by injecting chlorine gas into milk of lime solution.

Jan 1, 1998

By Kazmierczak J. B., Klein E., Kinscher J., Lizeur A., De Santis F.

In this work, we propose to implement machine learning methods for the automatic classification of mining-related seismic data. The approach retained for the classification is based on a Convolutional Neural Network (CNN) which has been tested and applied to two different mining datasets: the active ore mine of Garpenberg (Sweden), currently under exploitation, and the abandoned coal mine of Gardanne (France), where mining stopped in 2003. The first step of the approach consists in creating a well classified (manually) database of seismic signals separated in different classes as a function of the seismic sources. The selected database is then divided into two groups: train, containing the 70% of the signals, and test, which contains the remaining 30% of the signals within the selected database. The learning phase of the algorithm consists in creating a classification model based on the train group, which is further validated on the test group. The application of CNN for the automatic classification of Garpenberg and Gardanne seismic data shows, respectively, that about 88% and 98% of the seismic events of the two sites can be properly classified. These results demonstrate that machine learning could be a powerful tool for microseismic monitoring in mining and post-mining environments, which could be further extended to the whole automatic processing of seismic data, including signal’s classification as well as microseismic event’s localization.

Apr 26, 2022

By J. W. Gunnett

Abstract. The Surface Mining Control and Reclamation Act of 1977 (PL-95-87), Section 522, establishes requirements for state regulatory authorities to designate lands unsuitable for all or certain types of surface coal mining. Any party having an interest in an area that may be affected can petition for it to be designated unsuitable for mining. Section 522 could present major obstacles to the mining industry by typing up an area in an endless round of petitions. The program under development for Kentucky is examined and analyzed as an example for determining the hidden impacts of Section 522.

Jan 1, 1980