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By R. D. Peterson

Autocad has become the standard graphics package for the mining industry as well as the general engineering profession. This paper discusses the evolution that mine planning has undergone and the trend toward compatibility with Autocad. It discusses the common use of Autocad in mine planning and systems modeling using a program called ICAMPS developed by Ohio Automation. As an example of its usefulness the use of the interactive ventilation network modeling capabilities are discussed specifically and are applied to mine planning at an operating trona mine. The ventilation analysis feature of the ICAMPS software works from Autocad drawing of the as-mined map and the projected mine layout. Using on-screen displays of these maps and the snap-on feature of Autocad, the planner designates nodes in the ventilation network, connects them into branches and selects branch characteristics from a side bar menu. The color coded ventilation network appears with the branch parameters alongside each branch. The software calculates the length of airways, computes the branch resistances where needed, converts the input into the required format and passes this information as input data along to the PENNVEN simulation program written by the Pennsylvania state University. Output is available in graphical as well as report format. The color coded graphs include pressures at the nodes and flow quantities on the branches. Since the networks come from the mine maps, the ventilation schematic displays are to scale and can be plotted separately or superimposed on the mine maps.

Jan 1, 1995

By d&apos, L. F. G. Assumpcao

Kaolin samples from Rio Capim resources were treated in conventional and superconducting magnetic separators to study the main variables that influence the color removal process. Coating clays and delaminated clay were tested. Retention time (or pulp injection velocity), magnetic field intensity and matrix type were the' variables studied. The feed brightness ranged from 84.7 to 87.6 % ISO for the coating clays and from 80.7 to 85.4 % ISO for the delaminated clay. The results showed unleached brightness values higher than 88 % ISO for coating products and higher than 87 % ISO for the delaminated product, using a conventional magnetic separator with an applied field of 1.5 to 2.0 Tesla. With a maximum field intensity in the superconducting machine of 5.0 Tesla, unleached brightness values higher than 88.5 % ISO for both coating and delaminated clays were attained.

Jan 1, 1995

Within the research project "Mine Development" funded by the "Austrian Fonds zur Forderung der wissenschaftlichen Forschung (FWF) " (funds for scientific research) between 1991 and 1993 150 underground hardrock mines in Europe, Northern America, Australia and Japan have been visited to analyze their general design and layout. The main aim of the project was to develop strategies for accessing new underground hardrock mines and to establish a mine planning database. The investigation included mines in high developed countries only, with a comparable labor cost situation. This paper presents the results of one part of the project, which deals with investigations into the influence of different parameters on the design of the primary access for a mine.

Jan 1, 1995

By F. Robert Hubbard

IMCO Recycling Inc. has developed a new, patented technology for the production of fertilizer, K-SOIL?, as a by-product of its aluminum recycling operations. This new technology can substitute for conventional technology which now results in a saltcake residue that is placed in 'landfills. Four years of research and development work by IMCO culminated in a U. S. patent issued April 5, 1994. As part of the technology development effort, IMCO engaged the services of a nationally renowned research organization and a prominent university. These two organizations have conducted in-depth agronomy studies In the laboratory, greenhouse, and the field. Results have shown K-SOIL? to be performance equivalent, on a nutrient content basis, to conventional potash fertilizer. The first field applications on commercial farms were made in the spring of 1994. K-SOIL? is a potassium-bearIng, granular solid which may find use in fertilizer blends, direct application, and other forms of fertilizer products. The overall benefit of this new technology is to create a useful by-product rather than generate a useless residue and, thereby, reduce or eliminate the amount of salt cake now placed in landfills. As such, It is a significant, step toward IMCO's ultimate goal of complete recycle.

Jan 1, 1995

By R. L. Unger

Restricted fields of vision are a common problem with underground mining equipment. Also, when lighting systems are provided, they may be positioned where they cause glare. This restricts the visibility around the machines even further. To help address these problems, the US Bureau of Mines has developed a PC-based software package to aid in the analysis of certain human engineering aspects of mining equipment design. The software is available for use by equipment manufacturers and mining companies for design work on new machines, as well as for evaluating proposed modifications to existing machines.

Jan 1, 1995

By G. Pan

A geostatistical approach is proposed for the design of infill drilling programs. The method is consisted of three major steps: developing geological favorability models, delineating mineralization and ore envelopes, and classifying reserves or resources. Geological modeling aims at developing favorable geological zones in which drilling is designed. Modeling mineralization and ore envelopes establishes criteria on potential blocks to be drilled. Top target blocks should be those included within ore envelopes. The framework of resource categories includes five types: probable reserves, indicated reserves, indicated resources, possible resources, and barren. Indicated reserves or resources are the top priority to be drilled for the definition of minable reserves. Possible resources may be considered as targets for further exploration. The algorithms involved in the analysis include indicator favorablity analysis, ordinary kriging, and indicator kriging. A case study presented here involves a gold deposit of Carlin type. The deposit was delineated by a sparse drilling program with 230 feet of average spacing. The infill drilling program designed by the new method suggests a significant reduction on the number of holes from a regular-grid infill drilling pattern.

Jan 1, 1995

Design models for belt conveyors used in mines predict both the belt power requirements and belt tensions. Conveyors with slightly downhill profiles are more complex to predict due to the way that models such as CEMA interpret friction. Performance of a particular conveyor in relation to other conveyors in the same system requires an analysis of natural stopping times, braked times and take-up location. A review of CEMA-based PC models is presented for design of underground multi-flight belt systems.

Jan 1, 1995

By G. S. Adisoma

To address the problem of grade estimation in a general three-dimensional shape and the uncertainty associated with the estimate, the technique of jackknifing/block kriging short-cut is proposed. A new estimator called jackknife kriging is introduced first. Through the jackknife variance, a confidence limit for the reserve grade estimate can be calculated. Unlike the kriging variance, which is more a measure of data configuration and is independent of data values, the jackknife variance reflects the true variability of the data. This approach provides a simple way to set a confidence level for global estimation of resources.

Jan 1, 1995

By R. Hurman Eric

The electrode in a slag-resistance electric furnace is the central factor in the design and operation of the furnace by its role of conveying the smelting power, i.e. heat needed for the operation. The control parameters are the size and positioning in the slag bath which are defined by slag resistivity, furnace resistance, cell constant and power input sequence all of which are closely interrelated. The flow of heat generated by the electrode current determines the energy distributions and thus the furnace dimensions. Heat flow models concerning vertical, horizontal and combined two-dimensional flows are discussed. All these considerations are based on the experimentally determined slag properties such as its resistivity.

Jan 1, 1995

By T. M. Yegulalp

A numerical model is being developed to assess the enhancement of permeability by improved fracture connectivity by micro-hydrofracturing. A generic two-dimensional percolation model has been developed to test the impact of various field conditions on permeability. Field data from Cyprus Minerals' Mineral Park Mine has been used to establish statistical properties of the observed fracture systems. Results of statistical anlyses of the field data and examples of the use of percolation model are presented.

Jan 1, 1995

In recent years a number of explosive blends including ANFO, emulsion and watergel products have been used in a variety of ground types and applications. These `standard' explosives' technologies are not new, but out of the uses and applications, have sprung a new generation of tailored explosives that match the ground type and the operating environment. This is in stark contrast to the norm, where various patterns and loading configurations have traditionally been designed to accommodate the explosive. This paper discusses these tailored explosives and the explosives' technology behind why they work. Active tailoring of explosive formulations can save mining dollars while essentially leaving the explosive price unchanged. Tailoring explosives may lead to increased rock breakage, heave, digging rates; lower digging maintenance costs and in some cases replacing earth moving machinery altogether. Tailored explosives may have other benefits such as reduced over pressure compared with standard alternatives. The tailoring of explosive performance generally involves three major methods (other than changing the bulk density and sensitivity): (i) replacing fast burning reactants with slower burning reactants or vice versa; or (ii) leaving the explosive intact and diluting the entire explosive with slow burning or `inert' material; or (iii) changing the concentration of the fuel/oxidiser mix. When tailoring explosives for particular applications, authorising, testing, costing, manufacturing, and delivery systems must also be taken into account.

Jan 1, 1995

By D. R. Nagaraj

Secondary Ion Mass Spectroscopy (SIMS) was used to study copper ion adsorption, and its effect on subsequent sulfide collector adsorption, on pyrite and pyroxene minerals under flotation related conditions. Copper was found to adsorb on both of these minerals and cause enhanced sulfide collector adsorption. The distribution and depth profile of copper and collector on these mineral surfaces were obtained by using SIMS in the imaging mode. The results of this study have provided a valuable insight to understanding pyrite and gangue flotation observed frequently in operating plants.

Jan 1, 1995

By A. E. Ketler

Optical smoke monitoring fills an important gap in ventilation and fire safety: namely monitoring of smoky, low temperature fires where little CO and heat are generated. Smoke monitoring also avoids the nuisance alarms due to diesel exhaust, battery chargers, blasting and welding. The smoke optical density (OD) fire alarm standard specified by MSHA presents an opportunity for improved safety. Experience of actual mine usage of the SmokeBoss*100 is reviewed, with particular regard to effectivity, maintenance and cost.

Jan 1, 1995

By P. R. Taylor

Diamond films have been successfully formed in an inductively coupled plasma (ICP) chemical vapor deposition (CVD) system from several gas mixtures: CH,-H,, C2112-112, and C2112-112-02' Our previous thermodynamic study indicated that the substrate temperature could be lowered by the presence of oxygen species at moderate system pressures (0.3-0.5 atm) and that higher volumetric growth rates required a high temperature source and a moderate pressure system in CVD processing. The principal experimental results were consistent with the thermodynamic predictions. The deposited films were characterized by laser Raman spectroscopy, scanning electron microscopy, and X-ray diffraction. The films were well faceted and uniform, with the growth rates over 10 pm/hr on molybdenum substrates. The crystal size ranged between 1 and 2 microns for a two hour experiment. It was possible to decrease the substrate temperature to below 800 °C in this system.

Jan 1, 1995

By F. Dingwu

The latest technology and novel equipments in kaolin processing industry in China are described in this paper. Some typical experimental results are presented, which include laboratory-, pilot-or commercial-scale tests. The characteristics of kaolin processing technology are summarized, and the developing trends are indicated.

Jan 1, 1995

By Raja V. Rarnani, Robert L. Frantz

More than 100 scientists from diverse professional backgrounds have contributed their expertise to the Dust Center as investigators. Approximately 50 researchers served as principal investigators, with responsibility for directing the work on Center projects, from experimental design and implementation in mines and in laboratories to coordination of efforts within the research infrastructure of the Center. The professional biographies which follow demonstrate the breadth and depth of research capabilities brought to the Center by its principal investigators.

Jan 1, 1995

By Susumu Okabe

Injection metallurgy is widely adopted in various fields of metallurgical operations to achieve high productivity. The Mitsubishi Continuous Copper Smelting and Converting Process employs the top blown lance technique for the continuous supply of solid charges and reaction gases into the molten bath, where the agitated bath contributes to enhance the heat and mass transfer and the increased gas/liquid interface area accelerates the reaction. However, excessive splashing of the molten materials accompanied by the injection may cause an unexpected wear of the furnace lining. In order to estimate the splashing rate quantitatively, and to optimize the furnace design and the blowing condition, a physical model study of the top blown gas injection onto the liquid bath was carried out. An equation of the splashing rate was obtained as the function of cavity size, gas velocity and bath properties.

Jan 1, 1995

By B. A. Wills

Much research effort has been spent in attempting to reduce the high energy costs in grinding, but relatively little in developing methods to enhance the liberation of the minerals from each other. This paper presents some ideas on the nature and role of grain boundaries in mineral assemblies, and their influence on the propagation of cracks through the rock. It is argued that if the mechanisms of fracture are more clearly understood, crack propagation may be controlled in such a way that intergranular fracture dominates breakage, producing less fines and a higher degree of liberation.

Jan 1, 1995

By A. W. Khair

This paper deals with the evaluation of the interaction between rock and the cutting tool, and with methods for determination of workability, and abrasivity of rock. A description of instrumentation is included along with research on the wearing process of bit tips and pick consumption. Analyses of bit rotation, evaluation of cutting, normal forces and energy consumption is presented. Finally influence of the basic water jet parameters and water jet assistance on the cutting process of hard and abrasive sandstone is discussed.

Jan 1, 1995

By Kazuhiro Asai

Nippon Mining and Metals Company has an annual indium production capacity of 30 tons at its Saganoseki smelter and refinery. Lately, indium content in the. zinc smelting dust, one of the main sources, has been on the decrease while the amount of impurity in it on the increase. The present process at Saganoseki does not permit efficient elimination of a large. amount of impurity. Therefore, studies were conducted to improve its recovery process. As a result, a new indium recovery process consisting of leaching, solvent extraction and electrowinning has been developed. The new process was tested at a pilot plant and satisfactory results were obtained. This new process is discussed in this paper.

Jan 1, 1995