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By Ronald E. Feltman

Most engineering firms engaged in the design and manufacture of milling components and systems have established, through the years, a relatively well defined system design procedure. The process design engineer has at his disposal several alternative approaches to the successful completion of this task. Unfortunately, while these alternatives, at first glance, appear to be rather straight Forward, any attempt to implement them into a fully integrated commuter design program becomes increasingly more complex when one addresses himself to the problem in total. This paper summarizes Kennedy Van Saun's approach to the solution of this problem through a planned system design. Following the problem definition and discussion, a detailed analysis and system design synthesis is presented; the major aim here being to provide a system design which may be programmed and run on a relatively inexpensive computer installation such as the IBM 1130 system currently in use at Kennedy Van Saun. A summary section is also included, which Provides a general outline guide to the program systems design of equipment which, while quite different from milling system functionally, nevertheless lends itself to the approach used in this paper.

Jan 1, 1969

By B. R. Pothini, H. von Schonfeldt

In underground coal mining many excavated openings have a relatively short projected life span. To ensure safety for men and materials at a minimum cost over the projected operating life, only pillars for overburden support and roof bolts for support of the openings are used extensively. Mining activity constantly changes the geometry of the mine producing load changes on the structural support members of the openings that often induce unstable deformations which can lead to roof falls or pillar failures. The paper describes how simple deformation measurements can be used to design primary and supplementary roof supports and to predict roof falls and possibly pillar bumps. Specifically, bed separations in the roof measured directly with the help of borescopes and calculated from differential convergence data are used to optimize bolt links or support requirements for chemical stabilization of mine roofs. Roof falls are predicted on the basis of admissible values for cumulative convergence between roof and floor, convergence rate, and the change of the rate of convergence. The pillar extraction operations convergence anomalies detected from contouring identify bump prone pillars, while convergence and pillar dilation determine the yield zone in a pillar to verify pillar softening and de-stressing. Manuscript not received in time for publication.

Jan 1, 1983

By E. R. Hendrickson

About 1/3 of the world's supply of phosphate rock is produced in a relatively small area of the Florida peninsula east of Tampa. Until this past year, a circle with a radius of about 25 miles and centered on Bartow would encompass the major producing areas. During the past year producing areas have opened in North Florida which promise to vie with the Polk-Hillsborough County area in terms of proven reserves. In addition, new phosphate production is planned for counties to the south and west of the present fields. From the existing production areas, however, more than 19 million long tons of phosphate were mined in 1965. As mining engineers most of you probably are familiar with the methods of mining and beneficiating the pebble phosphate rock. You thus recognize that, although some water quality problems may arise from these processes, there is no potential air pollution problem. To make an economically useful product, however, further processing must take place. It is from this additional processing that potentially damaging materials may be discharged to the atmosphere.

Jan 1, 1966

By J. L. Francke

This paper describes the practices and methods used in a study of Time Domain Reflectometry (TDR) as an inexpensive deformation monitoring tool in underground excavations at the Waste Isolation Pilot Plant (WIPP). The WIPP is being developed near Carlsbad, New Mexico, for the disposal of transuranic nuclear wastes in bedded salt 655 m (2 150 ft) below the surface. Data collected from WIPP geomechanical monitoring are used to characterize conditions, confirm design assumptions, and understand and predict the performance of the deep salt excavation. The geomechanical monitoring program encompasses numerous geomechanical monitoring techniques ranging from inspection of observation boreholes to advanced radar surveys. In 1989 TDR was introduced as a monitoring tool with the installation of 12.7 mm (0.5 in) diameter TDR cables in the underground excavations. In 1993, a new TDR system was installed in a separate location. Based on experience with the previous installation, enhancements were implemented into the new TDR system that: 1.) extended the period of performance by increasing cable diameter to 22.2 mm (0.875 in), 2.) increased accuracy in locating areas of deformation by aligning cables with nearby observation boreholes, and 3.) improved data acquisition and analyses using a standard laptop computer, eliminating the chart recorder previously used. In summary, the results of a correlation between the TDR signatures to nearby observation boreholes and geomechanical instrumentation will be presented.

Jan 1, 1996

An appropriate scale-up methodology is very useful for ball mill design and optimization of the grinding circuit. To date, the scale-up is based on the selection and breakage function method using lab mill data. However, a major drawback of that approach is that the charge motion in a lab mill is vastly different from that in a large industrial mill. Therefore, in the methodology proposed here, first the energy of individual collision in the mill is computed employing the discrete element method (DEM). Then the breakage of particles as a function of collision energy is studied in a separate experiment. Together, this information constitutes what is known as collision energy based population balance method. The appropriateness of this method is shown for 38-cm ball mill.

Jan 1, 1998

By H. Colijn

Belt conveyors have proven themselves for many years as a dependable and low cost method of handling bulk materials at high flow rates. The success of a belt conveyor system greatly depends on the initial loading of the material on the belt. If the material is loaded on the belt at the center, at approximately the same speed and with minimum impact, then most of all belt conveyor problems disappear. Proper belt loading is primarily determined by the engineering and design of the conveyor transfer point. This paper will establish and discuss some general design criteria required for proper loading and transfer of materials from one conveyor to another. Specific attention is given to loading points, chutes, skirt board length and general design of transfer structures.

Jan 1, 1971

By Alizeibek Saleimen Nader

The intensive use of computers for mineral application at Serrana's phosphate mine in Jacupiranga, State of Sao Paulo, Brazil, began in the late seventies. The early hardware and software available are described in sufficient detail to allow comparisons between that solution and the new one, based on a personal computer and a new software package - PC MINE SYSTEM from GEMCOM SERVICES INC - that provides full color graphics capabilities plus mine design and planning tools. The process needed for adaptation to the new technology' and its impact on SERRANA S.A. DE MINERACAO are described. Finally, future enhancements to the System and mine control and planning are focused.

Jan 1, 1989

By R. L. Hills

America's industry uses about 44% of the total energy consumed by the nation directly as fuel burned in industrial plants or indirectly as fuel burned by utilities to provide electric power. In addition, industry requires raw materials or feed stocks derived from fuel sources or having fuel value. This represents about 11% of total U. S. energy consumption, bringing industry's portion to about 55%. Adding that portion of energy consumption required by the transportation sector to move raw materials, intermediates, and finished products, the total energy impact of industry approaches 213 of total U. S. consumption. It is obvious that American industry has the largest share in the task of balancing energy demand and supply. What are we going to do? -- We must increase the supply of energy and increase the beneficial results obtained from each unit expended. Both avenues, unfortunately, are limited in extent and speed. Increases in supply cannot occur without drastic and permanent increases in cost. These increases in cost are un- desirable and inflationary but do provide incentive for the rational businessman to expend the effort and money required to improve the effectiveness of energy in industry.

Jan 1, 1975

By 000-000-604

HISTORIACAL INTRODUCTION Mineral processing has three principle branches, to quote Taggart, "Ore Dressing, which comprises the methods of separation of solids in inorganic crude by means which do not affect substantial chemical change; Extractive Metallurgy, which utilizes chemical reactions for separations of constituents from solids in inorganic crude; and, Fuel Technology, which employs both physical and chemical methods for separating and rearrangement of liquid gaseous and solid components in crude oil and natural gas, tar sands, shale oil, or coal." The scope of this handbook covers the first two classifications, that is, "ore dressing" and "extractive metallurgy," which have been combined in one term: "mineral processing." For a brief history of the development of mineral processing, one could well refer to the Introduction, Sec. I of the Handbook of Mineral Dressing by Taggart, Froth Flotation, Principles of Mineral Dressing by Gaudin, and the original Richard's Ore Dressing, volume No. 1, first published in 1903-1905. In these references and the references given in them a coverage of the history of "ore dressing" can be found and studied at the reader's leisure. For the history of extractive metallurgy as well as ore dressing, the bibliography in General References, taken from a History of Ex¬tractive Metallurgy by F. Habashi, will give a good background for those who are interested in more detail on the history of metallurgy in general. Mineral processing covers a very wide field as is illustrated by the topics discussed in Part II of this handbook and dates back to the early history of man which started with the production and use of native minerals such as gold, silver, copper, mercury, and meteoric iron which were washed or picked from deposits on the surface of the earth and worked because of their malleability. Later, melting was discovered and then it was possible to cast objects of these metals, excluding mercury. The discovery of a method for reducing the metal¬lic oxide probably was developed from melting fragments of oxides or roasted sulfides with charcoal, so that the native metal could be produced in simple blast furnaces such as are used today in rural parts of Spain, China, and elsewhere. Eventually, it was learned that iron could be readily worked when hot, which resulted in its replacing bronze for tools, weapons, and cutlery. Carbon dating and correlation with the Brittle Cone pine has

Jan 1, 1985

By Richard L. Profio

A practical analysis of the three basic elements of a mining shovel's productive capacity. Payload Speed Reliability Improved dipper fill factor is explored referring to the latest generation of wide dippers combined with higher "bank horsepower" capabilities of modern drive systems. Cycle time improvement is reviewed including overall attachment geometry and coordination of motions. A specific case study is detailed. Basic reliability of welded structures, machinery components, and electrical systems are related to operating costs. Three basic elements determine a mining shovel's long term productive capacity: 1) Average payload per cycle. 2) Average cycle time; and 3) Reliability. This paper deals with productivity gains that are possible with existing shovels as well as new equipment.

Jan 1, 1984

By James P. Bowersox

Modem mineral processing plants handle large amounts of ore and produce large tailing streams. Plant performance can be optimized when the water is quickly recovered with a thickener. The caisson thickener was developed to overcome process and mechanical problems with the conventional traction and center column units. The caisson is a hollow center column that serves as a pump house. The rake arm structure is supported by a hydrostatic bearing which sits on top of the caisson. The caisson thickener with a hydrostatic bearing has operated for many years in several mineral processing applications.

Jan 1, 1981

By H. EI-shall

In this paper, the results of a fundamental study involving zeta potential and turbidity determinations of solid suspensions are discussed. Illustrations of how these results are utilized to design field applications of solid grade polymers to clarify mine drainage water are presented. Other applications in different industries are also reported. The operational and economical advantages are examined.

Jan 1, 1994

By V. Srivastava, T. Ghosh

"Modeling and Simulation of SAG Mill has been widely used in design and optimization of mill performance in terms of its power draw, processing capacity and product size distribution. However, these models are solved under steady approximation and do not provide any information on mill charge distribution in real time. This paper attempts to characterize mill contents by solving Whiten’s first order contents based model in Matlab/Simulink environment. The parameters in the model such as breakage rate (S), discharge rate (D) and appearance function (A) were estimated utilizing process and design data collected from a gold mine operating in Alaska coupled with nonlinear parameter estimation scheme. This model is then utilized to predict dynamic response of other key operational variables such as mill power, bearing pressure, charge level and product size distribution. The transient response of mill behavior with respect to changes in feed size distribution, tonnage and mill feed water is also presented. This dynamic simulation approach can be used for practicing different control strategy and training purposes. The observed response of mentioned variables was validated utilizing dynamic response data from the plant to encompass operational characteristics of SAG Mill behavior. Keywords: SAG Mill, Dynamic Modeling, Simulation, Nonlinear Parameter Estimation. INTRODUCTION Grinding in mineral industry is one the most important steps in the process of size reduction and plays a crucial role in determining the overall economics of the milling plant. Much of the efforts focused on improving the process efficiency using modeling and simulation have been practiced by researcher and engineers. However, up till now these models were simulated under steady state approximation because of their complex nature and difficulty in programming them in a dynamic framework. Steady state simulations have been successfully utilized in circuit designing, capacity planning and pre-flowsheet optimization. The maturity in steady state models is because of its applicability and regular use in steady state simulation packages such as JKSimMet, Limn, ModSim, etc. With the advent of equipment such as SAG and AG mill has been a recent shift in the simulating these models using dynamic approach. Because of the economic benefits of these devices and ability to act both as a primary grinding device and as secondary or tertiary crushing device they have gained a large popularity and are now universal to any milling plant. However, these device poses a real challenge to engineers and researchers in terms of operation and control. The major reason attributed to problems faced is because the ore constitutes the major portion of the charge in these devices when compared to ball and rod mill. This rock charge is subjected to disturbance such as changes in feed size distribution and ore hardness which results in unstable operation and frequent mill stoppages. One way to prevent this is to measure and control these external variables, however, lack of available instrumentation and unavailability of sensors to measure these variables has foiled the understanding of complete process occurring inside the mill thereby, inhibiting development of proper control system."

Jan 1, 2017

By D. Gatzemeier

The Jewett mine is a surface mine in central Texas, producing about 8,000,000 tons/year of lignite. The mine covers 46,000 acres of land. Approximately 430 people are employed by Northwestern Resources Company and through their efforts, the Jewett Mine is one of the most productive mining operations in the country. The Jewett Mine utilizes a unique structure of staff to convert Operations Research into plans which can be implemented at the "front line" level of the Operations Team. This planning not only makes the mine cost effective and efficient, but promotes creativity in mining, which promotes ongoing research to lower the cost of mining.

Jan 1, 1993

By Michael J. Mankosa

Carpco has recently evaluated the use of various mineral processing techniques for secondary materials recovery. These applications include recycled foundry sands, plastics and secondary metals. This paper describes different recycling applications and the associated separation solutions. Results from extensive laboratory-and pilot-scale test work in each area are discussed. Industrial installations resulting from this test work will be presented. A detailed description of an industrial installation patented by Carpco for the recovery of plastic and metallics from current waste by-products is presented.

Jan 1, 1997

By Francois E. Heuze

The mined geologic burial of high-level nuclear waste is how the favored option for disposal. The underground repositories must keep the waste away from the biosphere for very long times - several thousands to tens of thousands of years. Also, access must be maintained to the vaults for several tens of years, so that the waste can be retrieved, if necessary. Both the excavation of the underground chambers, and the radiogenic heating will disturb the rock mass. The overall rock mechanics problem is to understand and predict the processes associated with these perturbations, and their impact oh the isolation and containment of the waste (3)**. The specific rock. mechanics issues which have been identified for the three candidate hard rocks (basalt, granite, and tuff), are summarized in Table 1. The table also indicates the level of adequacy of our knowledge in the areas of the various issues. Such an evaluation is consistent with the general consensus of the rock mechanics profession, as explained in several key reports and publications (1 to 11). The main shortcomings of today's rock mechanics for waste repositories can be summarized as: ? lack of resolution for remote mapping of fractures in rock masses ? great difficulty in testing large volumes of rocks to determine their mechanical properties.

Jan 1, 1981

By Richard H. Johnson

White Pine Copper Company, a subsidiary of Copper Range Company located in Michigan's Upper Peninsula, mines a Precambrian sedimentary deposit containing finely disseminated chalcocite, native cop- per and native silver. Silver occurs predominately in certain strata and presently provides a mill head averaging 0.25 ounces per ton. This technical publication traces the development of silver recovery at White Fine beginning in early 1961. White Pine refined copper contains an excess of silver over and above that required to impart Lake Copper properties. The copper does not require electrolytic refining to meet industry purity requirements, nor is there sufficient silver to justify electrolysis.

Jan 1, 1970

By John C. Draper

Little precise information is available on the effect of mining on the surface topography. It is often assumed that after mining the surface will simply sink. This is not an infallible conclusion as is well illustrated in two of the three examples herein. This paper describes the results of an attempt to precisely measure the surface movement in the area around coal pillars left in place for three oil wells in a completely mined and caved area at the Harwick Mine of the Duquesne Light Company. The dates when the various measurements were made are shown on the data sheets and indicate the rate of surface movement. These oil wells are identified as wells Nos. 2, 3, and 6. This mine property is located on the north side of the Allegheny River at Cheswick, Pennsylvania, and extends in a northerly and westerly direction about five miles. The three well pillars are situated on the westerly side of the Bessemer and Lake Erie Railroad some 2,000 feet from Rural Ridge, Pennsylvania (Fig, 1).

Jan 1, 1964

By D. L. Shenck

The Navajo Mine is exclusively a multiple seam surface coal mine located in the northwest corner of New Mexico, and entirely on the Navajo Indian Reservation (Figure 1). It is owned and operated by the Broken Hill Propriety Co., Ltd. of Melbourne, Australia. The mine began production in January 1963 with a long term fuel supply agreement with the Four Corners Power Plant. The 2175 MW nominal generating capacity of the Four Corners Power Plant consumes 8-8.5 mm tons of coal annually. With estimated reserves totaling 1.1 billion tons of strippable coal, only one third is presently committed to the generating station. As development has continued over the years, mining operations have advanced into more complex geologic areas to satisfy the utilities demand for coal.

Jan 1, 1990

By Fun-Den Wang

In underground coal mines, three types of roof failure (2)*, tensile, local, and shear, occur in the development entries and in room-and-pillar extraction areas. Most of the tensile failures in the roof at the center of the mine opening as well as those local failures due to fracture or jointing can be controlled by roof bolts, trusses, and timbering. However, control of the shear failure at the sides of the roof (or the cutter-roof caving) has not been successful with ordinary roof control methods. The only effective method, when there is an indication of cutter-roof caving, is to use cribs, which are costly and make transportation, ventilation, and production difficult. Frequently, the operator allows the cutter roof to cave and then cleans it up rather than trying to stop it. This shear type of roof failure is often associated with large areas which may progressively involve several hundred feet of roof caving at one occurrence. At times, this shear failure occurs suddenly with little or no warning. This can result in buried equipment and great danger to the safety of personnel. This shear failure may be due to one or more of the following: high stress concentrations at the corner of the roof from (1) high horizontal to vertical load ratio, (2) orthotropic elastic properties of rock and coal, (3) greater stiffness of the immediate roof layer than of the secondary roof layer, (4) viscoelastic behavior of rock and coal, and (5) geometry and material properties of the geologic setting. Removing or reducing the high stress concentration should improve the roof stability. The structural analyses of models of two typical

Jan 1, 1972