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By Fred W. Shultz

In the past we have been somewhat harrassed by the terms "'quality control" and "process control". This is especially true where the industry is dependent upon the chemical analysis of their product which in turn informs them how, well they have been controlling the process. The information which they have received, in most cases, is of an historical nature rather than of current value. The word "control" is to have more significance in future operations. This is particularly true in the metals industry. As the industry continues to process lower grade ores, and processing costs continue to rise, they must obtain more information faster to exercise "control" to its fullest extent.

Jan 1, 1963

By Robert J. Russell

The importance of grinding as a unit operation in all industry has caused much effort to be expended toward improving the facility with which grinding can be done. Endeavor has continued nearly 100 years to formulate laws governing crushing and grinding. This has not been without controversy. However, grinding is an experimental science and our useful knowledge originates in experience. The recorded experience is grinding history. Today, many types of size reduction equipment, each with variations, are available to industry. Frequently, more than one type of grinding equipment will meet a requirement of grinding. However, an economic evaluation of installation and operating costs generally indicates a preferred type. The selection of grinding equipment requires' a consideration of the purpose in grinding, the characteristics of the material to be ground, equipment available for grinding, and the manner in which it can be applied best.

Jan 1, 1960

Power consumption of stirred media mills has been studied by an approach developed from work on stirred reactors. Relationships between torque required to rotate both disc and pin impellers immersed in dense particulate media as a function of speed, impeller and tank dimensions, and other relevant variables are evaluated. Data collected during numerous different experimental conditions are analyzed. The results can be summarized and presented in the form of characteristic plots, general equations and dimensionless group correlations involving power and modified Reynolds numbers. Special attention is directed towards the rheological properties of the media, which is considered as non-Newtonian liquids and hence, the equation of power law liquids is employed. Procedure for estimating parameters of effective viscosity and scale-up guidelines with respect to power consumption are put forward.

Jan 1, 1994

By A. Ghosh

Commonly used predictors of ground vibration from blasting, being linear in log-log plot, do not model the underlying physics of wave attenuation. Amplitude of the wave decays with distance due to geometrical spreading and inelastic attenuation producing a nonlinear carve in log-log scale. The nolinear decay of seismic waves has also been observed from non-explosive sources, such as, pile driving, drop hammer, traffic, etc. The improved predictors, by explicitly taking these two mechanisms into consideration, model the data trend extremely well at all distance ranges. Actual field data from different studies have been used to validate the improved models.

Jan 1, 1991

By D. E. Ranta, Jean-Michel Rendu

It is generally recognized that geologic input is required for the results of a geostatistical study to be meaningful. However the link between geology and geostatistics is often complex and not well understood. A geostatistical evaluation can be divided into four phases: Background discussions, computation, reserve reporting and reserve audit. Each one of these phases is described, as well as the role the geologist should play during their completion. This role will vary depending on the geology of the deposit being studied, the geostatistical method chosen and the computer hardware and software being used. The geologist's acceptance of the results is needed if the geostatistical model is to have any credibility. The most significant obstacle to a meaningful study comes from the difficulties geologists and geostatisticians often encounter when attempting to communicate with each other.

Jan 1, 1992

By Paul A. Gerding

PURPOSE: Presentation to Society of Mining Engineers, Technical Session, Wednesday, February 19, 1958 - 2:00 P.M. General Industral Minerals - Penn Top South The silica industry is relatively small and in general is made up of small plants located near the consumer. In the United States there are approximately 155 established operating plants located in 37 states, extending from coast to coast. Silica, in varying degrees of chemical purity, enjoys a very diversified market. Silica is the basic ingredient of glass, bothcontainer and flat glass, and is used for grinding and polishing of flat glass up to the final polishing stages where rouge is generally used. Silica is used for foundry molds and cores, sandblasting, stone cutting, refractories, placing sand in furances, glass coatings and linings, laboratory glassware, construction, oil well fracturing for increased oil flow, filtering purposes, silicate of soda, silicon carbide, and others.

Jan 1, 1958

By R. C. Runvick

Gypsum resources are significant in the midwestern United States, with specific deposits varying in "place value" relative to the major markets served. Underground and surface mining operations produce gypsum from sedimentary rocks ranging in age from Silurian through. Jurassic. Although reserves tend to be limited at individual operating properties, potential resources are vast and future development will hinge principally on market growth and changing economic conditions. Most critical of the variables affecting the industry in both the short and long term will be the availability, type and cost of energy and both processing and distribution.

Jan 1, 1980

By G. Ferrara

To obtain a reliable comparison between conical and cylindrical separatory vessels used in dynamic dense medium separation systems, the following studies were made: (1) study of the swirling flow in conical and cylindrical vessels using laser-Doppler velocimetry (LDV); (2) study of the behaviour of suspensions of magnetite and ferrosilicon in water in both separators. It was found that: (a) the tangential velocity profiles differ in conical and cylindrical vessels: in a conical cyclone free vortex conditions affect the largest part of the vessel, while in a cylindrical vessel, the motion approaches that of a forced vortex, i.e. that of a centrifuge; (b) the conical vessel manifests higher centrifugal acceleration and very strong densifying; the density differential, and hence the density gradient inside the vessel is large; (c) the cylindrical vessel manifests lower centrifugal acceleration and low densifying, i.e. low density differentials, and hence, the density gradient inside the vessel is small; (c) due to greater densifying, the density cut-point in cyclones is higher than the operating medium density, while in cylindrical vessels the density cut-point is closer to the medium density. The results provide an interesting description of the differing behaviour of conical and cylindrical vessels and help explain the differences in performance between the two types of separators.

Jan 1, 1998

By Donald M. Duncan

An acceptable source of concrete aggregate is available in Kansas City in a continuous, medium bedded, slightly dipping limestone unit. Removal is accomplished in shallow depth, 12 feet to 17 feet high, room and pillar mines. The accepted empirical design spaces 20 foot pillars 60 feet on center. A portion of the 20 foot unit is left in place for roof support. Rock and soil cover is variable to 100± feet maximum. Long-term stability of these mines is affected by numerous factors, including the above mine-rock profile, ground water conditions and mining practice. Crusher-run aggregate sells at the mine for $2.20 per ton, yielding a gross income of $2.00 to $2.80 per square foot of mine. Use of mine space for real estate development requires a new perspective in mine development. Mining practices to obtain long term stabile structures can become an over-riding factor as compared with minimum production costs and maximum extraction ratios. Poorly mined areas are unusuable for secondary purposes. Development cost for lease space in less desirable mines is substantially greater than those planned for a secondary use. Real estate development in mine space involves unique engineering problems. Properly engineered developments offer singular advantages. Warehouse lease space sells for $.50 to $1.00 per square foot per year; fully developed office areas may double these values.

Jan 1, 1968

By John C. Nixon

In 1959, The Australasian Institute of Mining and Metallurgy (Aus. I.M.M.) was asked by the Federal Government of Australia and the State Government of South Australia to join in the formation and management of a new contract research organization which was subsequently named The Australian Mineral Development Laboratories (Arndel) ? This body was formerly the Research and Development Branch of the South Australian Department of Mines which had been set up to develop the Radium Hill uranium deposit. It had then gone into contract R&D and the State felt that it would be more appropriate for the Branch to become a separate national organization. The Aus. I.M.M. decided that a professional institute could not participate directly in Arndel and, as there was no other suitable industry group to do so, it formed the. Australian Mineral Industries Research Association Limited (AMIRA). AMIRA held its first Annual General Meeting in September 1959 when the first Council was elected and the Memorandum and Articles of Association were adopted. The initial task of AMIRA was to raise guarantees of work or cash from its members to underwrite Arndel for the first five years of operation. The Federal and State Governments also provided guarantees and Arndel commenced operations in January 1960.

Jan 1, 1977

By David F. Gibson

This paper presents an outline of several models that have been developed to aid surface mine planners evaluate alternative mining methods and dragline sizes. The models presented belong to a larger group of models that are incorporated in the SEAMPLAN computerized mine and reclamation planning system. SEAMPLAN was developed in the College of Engineering at Montana State University. Initial funding for the development was derived from the USDA Forest Ser- vice and EPA. Enhancements to SEAMPLAN are currently being funded by DOE (Contract DE-AC22-80ET-14173). SEAMPLAN is a comprehensive surface mine and reclamation planning tool that contains a number of major modules: Data Entry and Review, Production Analysis, Reclamation Analysis, and Impact Analysis. The Production Analysis Module contains programs that enable the user to evaluate alternative methods of removing overburden in a surface coal mine and then to assess auxiliary activities required to support the overburden removal operation. A set of these programs addresses the use of draglines for removing overburden. Six basic dragline mining techniques have been modeled. For one-pass dragline operations four methods can be analyzed: (i) simple side cast, (ii) side bench, (iii) extended bench, and (iv) extended bench with side bench. Two methods of two-pass operations are modeled: (i) single dragline, and (ii) tandem draglines.

Jan 1, 1982

By M. C. Radomsky

Approximately sixty, small, surface coal mines in Pennsylvania participated in a program designed to improve safety performance in the workplace. The method involved the use of safety sampling and observation to assess the safe standards of worker behavior and work conditions. Data were collected through the use of operation-specific, on-site safety records covering seven major occupational units. Workplace events observed (acts and conditions) were assigned a hazard classification; feedback, both immediate and delayed was initiated to improve safety performance. The experiences drawn from this pilot project have proven the need to continue to pursue this behavioral approach; however, a stricter methodology needs to be adopted in the collection and analysis of data.

Jan 1, 1987

By Kenneth K. Landes

So far my consulting in industrial minerals has been confined principally to carbonate rocks,-salt, coking coal, and glass sand. Much of this work has been for companies either too small for a full-time geological staff or unaware of the value of employing one or more qualified geologists permanently. It gave me considerable personal satisfaction to see several of the latter companies employ one or two full-time geologists after the completion of a consulting contract with them. One possible reason why some companies lack the wisdom to hire geologists is that they are dominated by engineers who still subscribe to the old idea that engineers are self-sufficient in all fields. They could have learned this from their professors. I once knew a Dean of Engineering who got purple in the face when a faculty committee was discussing the financing of a broad gauged engineering project and suggestions were made that assistance be obtained from the Schools of Business and Law and from some of the science departments tie pounded the table and shouted "Engineers are trained to handle all this!" In teaching engineering geology some years ago I used to tell the class repeatedly that the course would not make them geologists, that the purpose was to teach them

Jan 1, 1972

By Gordon R. Wicker, Willem P. C. Duyvesteyn, Robert E. Doane

A versatile acid leach process has been developed which is applicable to a broad range of oxide nickel ores. Inherent in this process are high recoveries of nickel and cobalt, as well as a relatively low energy consumption. These features extend the range of economic exploitation of laterite deposits to low grade limonites and to garnieritic ores not suitable for pyrometallurgical processing. Particular advantages can be realized in treating orebodies containing both limonite and garnierite and ores containing significant amounts of cobalt.

Jan 1, 1979

By L. S. Rubin

The efficient and acceptable disposal of fine coal refuse (28MxO) is one of the highest priority problems facing the coal industry today. For many years the established system for the disposal of this fine refuse slurry has been to concentrate the solids in a static thickener and pump the resulting 20-40% solids underflow to lagoons or impoundments. Although this technique has served the coal industry well, increasing environmental concerns and refuse related disasters, such as Buffalo Creek, West Virginia and Aberfan, Wales, Great Britain have resulted in federal and state regulations which now control fine refuse disposal methods. As a consequence of these regulations, the capital costs of constructing, maintaining, and operating regulatory complying impoundments has become in many cases economically unattractive. Areas processing topologies similar to those coal preparation plants of the Appalachians are particularly burdened by these regulations and are consequently turning to alternatives for handling and disposal of their fine coal refuse. The basic requirements of impoundment alternatives as defined by environmental and plant demands are: (1) A relatively solids-free liquid (1000 ppm or less) to serve as plant make-up water in a "closed circuit" system, and (2) a sufficiently dewatered solids product which can be combined with the coarse refuse to form a compactable stable land-fill.

Jan 1, 1978

By Y. C. Kim, F. Szidarovsky

The technique of linear kriging as a grade estimation method of mining blocks is reason¬ably established in the mining industry. During the kriging process, negative kriging weights ([]i) are sometimes encountered. Due to negative kriging weights, negative block grades may be obtained in some extreme situations, which makes no practical sense. To guarantee nonnegative weights, an additional constraint is required in the kriging system of equations. Unfortunately, the nonnegative weight constraint results in a set of nonlinear system of equations. In this paper, a derivation of the resulting set of nonlinear equations is presented and a numerical algorithm is developed for the solution of the equations. Because the algorithm developed does not remove negative weights arbitrarily, optimal nonnegative weights are always guaranteed. Results obtained using the developed algorithm were compared with those using the standard linear kriging, in terms of computer, time and the estimation results. Both the computer time and the kriging variance were found to be higher with nonnegative constraint, as expected. However, some systematic pattern was observed in the kriged values (i.e., over-or underestimation) with or without the nonnegative constraint. The study also demonstrated when one should generally expect negative kriging weights in practice, and what practical impact the negative weights can have on the kriging estimates.

Jan 1, 1987

By C. R. Euston, B. T. Field, W. E. Lindquist

Pyroprocessing applications in the minerals industry range from low-temperature drying to high-temperature reactions. Material characteristics and process requirements range over a very broad spectrum and can confuse plant engineers trying to select a pyroprocessirtg system for their plant. This paper examines the important process variables and offers empirical guidelines to assist in a user's overall process evaluation.

Jan 1, 2000

By Don K. Smith

The northern zone of the Indus Basin comprises a vast area of essentially level land in West Pakistan which is irrigated by means of a complex system of canals that distribute more water to more land than any other irrigation system in the world. In spite of the development of this extensive irrigation system, production of food and fiber has not met the requirements of the country. The major reasons that crop production has not reached anticipated levels are the lack of adequate irrigation supplies and effective subsurface drainage. As a result, yields per acre are among the lowest in the world for areas where irrigation is practiced, and many thousands of acres of valuable crop land have been removed from production or are seriously affected by salinity and waterlogging. To rectify the problems of irrigation supply and drainage the Government of Pakistan has undertaken a program of Salinity Control and Reclamation which is being administered by the Water and Power Development Authority. The Authority retained Tipton and Kalmbach, Inc. , of Denver,, Colorado as Engineers for the program in the northern zone of the Indus Basin. -This program consists of the construction of about 30, 000 irrigation wells to provide drainage for waterlogged lands and full irrigation supplies, including leaching requirements, for; all cultivated lands. The program will ultimately ensure the productivity of 20 million acres and will involve an annual pumpage from ground water storage of nearly 40 million acre-feet of water. The value of the crops produced when the program is in full operation will be 4 to 6 times the value of the crops that could be produced without the benefits of this program.

Jan 1, 1967

By Robert C. Salak

The era of low-seam mining with continuous haulage has been here for quite some time. Typical tonnages in companies such as Terry Glenn Coal are currently averaging 405 tonnes per shift in .8m coal. JoAnn Coal has averaged 453.6 tonnes per shift in .775m to .825m coal for the past four years. John Chaney of Chaney Coal has averaged 297 tonnes per shift in .6m to .65m coal. There are many other mines that are experiencing similar success and with maintenance costs that are averaging $.10 to $.40 per tonne. These figures have been documented and can be verified by the operators.

Jan 1, 1981

By S. C. Sun

Very little information is available concerning the magnetic properties of minerals and only recently has there been any attempt to correlate magnetic susceptibility with varying chemical composition1. The work described here covers a study of the relationship and chemical composition of both the rutile and sphene types of titanium minerals. The relationship between the magnetic susceptibility of three selected mineral specimens and the applied field strength is also presented. Experimental: The equipment and procedures used in this in- vestigation for crushing and cleaning the mineral specimens and for determining the magnetic susceptibilities were the same as that employed by Spokes and Mitchell1. The particle size of-the measured specimens was limited to 270/325 mesh.

Jan 1, 1959