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By S. R. Brown

A number of relatively recent factors associated with the design of new metallurgical processing plants have made the effective training of operators a requirement for a successful start-up. Some of these factors include large capital investment in a minimum of processing lines, highly complex process control systems, and stringent regulations on plant effluent, to name a few. More than ever, operating mistakes during the start-up phase can lead to substantial delays in achieving design production, as well as problems with government authorities if permit limits are exceeded. The only way to assure your return on plant investment is to ensure new plant operators have the knowledge to properly run the plant from the outset. A comprehensive set of operating manuals specifically targeted for plant operators and foreman, written by experienced operating personnel, is the only effective way to provide the necessary information for start-up-related training.

Jan 1, 1995

Thank you and good morning. I am delighted to be here and to see so many of my colleagues and competitors. The general topic of this week's conference - World's Best Practice in Mining and Processing - suggests a focus on mining and processing. I am somewhat of a `jack of all trades and a master of none'. But I'm not even a jack when it comes to mining and processing technology and practices, and so I will leave those topics to speakers better 'qualified than I. Instead, what I would like to do is give you my thoughts on the best management practices of mining. You see, the times are changing for the mining business. There is great uncertainty in our industry. Anyone who received their education in an English-speaking school probably remembers the famous poem `Invictus' by William Ernest Henley. The two most famous lines from that poem are, if you remember, `I am the master of my fate; I am the captain of my soul'. The fact of the matter is that the metals industry, including the copper industry, is not the master of its fate. To a great extent we're at the mercy of forces over which we have little control, such as the world economy or political situations in individual countries. The copper industry is like a surfer at Manly - we can't influence where the wave is going; all we can do is stay in front of the curl and on our board. Historically, discovering, developing and processing ore reserves were the primary facets of our capital intensive business. To stay competitive today, we must invest equally in intellectual capital - our employees - in order to succeed in the face of economic, regulatory and political challenges and global competition (Schonberger, 1986). Everyone seems to have a different theory about being competitive. A lot of people use sports analogies when talking about competition. Others, like American businessman and former US presidential wanna-be Ross Perot, take a more interesting approach. In Mr Perot's hypothetical corporation, competition is a lot like having a snake in a factory. If someone sees a snake, the first thing they do is create a committee on snakes. Then, the committee on snakes meets and discusses the problem for a couple of years. The most likely course of action is nothing. Everyone figures that the snake hasn't bitten anyone yet, so they just let him crawl around the factory floor. Perhaps a vice president of serpentine affairs is appointed to continue watching the snake - making sure it doesn't grow. Ross Perot sees it a little differently. In his corporate world, business needs to build an environment where the first guy who sees the snake kills it. Of course in our industry, we better make sure the snake isn't on an Endangered Species List before we go after it! I am not going to talk about competition and competitive forces in terms of sports or snakes, but I would like to share some thoughts with you about how the mining industry can better utilise competitive thinking to get ahead and stay there. You may be wondering how an executive from a 160-year-old company could know much about competitive spirit, but the founding ancestors of Phelps Dodge were wizards at identifying

Jan 1, 1995

By K. Biswas

So far, all pillar design methods or approaches consider the coal seam as a uniform structure From some mine visits in northern Appalachian Region. it is found that some coal seams have binder or parting material within the coal scan with varying thicknesses and numbers- And it has also been found that these kinds of hinder materials tire prone to weathering when exposed to ambient mine moisture In this paper an attempt has been made to study the weathering susceptibility of parting materials and coal when exposed to moisture and a two dimensional finite element analysis has been carried out to study the effect of the presence of partings on the structural integrity of the coal pillar in terms of short-term and long-term stability.

Jan 1, 1995

By Ronald Erdmann

Today the BOF filter dusts and sludges are mainly dumped due to their zinc contents. By typically ranging from 2 to 5 % they prevent the filter dusts and sludges from beeing recycled via the blast furnace route. Based on the different discharge kinetics of Iron and zinc during the main blowing period In a bottom stirred BOF a simple and efficient system for recovery allow zinc fractions has been developed. The obtained material Is suitable for recycling without nsc of shell formation In the blast furnace. Different subsequent development steps have been performed. By starling with a very simple lime dependent model the sludge from the BOF off gas cleaning system was collected in two different sludge channel systems. This model based an the fact that most of the scrap based zinc Is discharged from the melt within the first eight to ten minutes of the BOF process. To Improve the system a spectroscope zinc sensor was Installed at the hot section of the off gas cleaning system to get more reliable informations on the actual zinc concentation of the BOF dust. By use of the system up to 50 % of the BOF sludge can be recycled.

Jan 1, 1995

By E. DeLilia

For the past 30 years, surface mines have moved toward more highly mechanized, automatic systems that continuously mine overburden and ore to in-crease productivity, lower operating costs and minimize manpower needs. To achieve these goals, mine operators must be involved in every step of the machine procurement process. Several factors are involved in making the machines operate economically and efficiently: ? Prudent engineering. ? Proper planning. ? Realistic feasibility studies. ? Effective specification. ? Thorough training of the mine personnel.

Jan 1, 1995

By X. W. Pan

It has been found that the MnO content of a slag decreases sharply when direct current is applied to a 1T1£tal-Slagsystem consisting of liquid Mn-Si-Ccsat metals and MnO-SiO2-CaO-AI203 slag in graphite crucibles. This paper reports a preliminary investigation into the electrochemical effects of direct current on the metal-slag system, the silicon content of the metals, and the MnO content of the slag. The results show that, when a direct current of 7 A is maintained, the MnO content of a metal containing 10 to 11 per cent silicon by weight is reduced rapidly from 26,5 to 17,2 per cent by weight. This reduction seems to proceed further when the process is continued. When the direct current and the voltage are kept constant at TA and 4 V respectively, the MnO content of a metal containing 1 to 2 per cent silicon by weight is reduced to 1 from 25 per cent by weight, which results in a manganese yield of 96 per cent.

Jan 1, 1995

Hoisting ropes are constructed of wires and strands positioned helically around the axis. This helical positioning causes that, in the rope loaded at the end with the weight Q, the longitudinal displacement u, axial force P, torsional displacement v and constant torsional moment M are generated. More over, the proper weight of the rope q gives the force acting along the axis of the rope. This force changes its value from 0 at the bottom to qL at the top. This force gives, along its length, a variable torsional moment making the rope rotate. During the movement of the conveyance downwards the falling part of the rope rotates, which makes it untwist on the section up to the half-depth of the shaft and twist on the other half-depth. As the result, the twisting lay of the rope changes increasing in the upward direction and decreasing downwards. The angle of twist of the strands changes in an apposite way. When moving upwards, the uplifted rope does not twist and retains its state of deformation up to the moment when it passes over the pulley. Next, the cycle of untwisting and twisting repeats during the movement of the other conveyance downwards. This phenomenon is known from mining practice. It was also analysed, in the works of Glushko (1966) and Popowicz (1963).

Jan 1, 1995

By O. Forsén

A new cell construction was designed for the study of the electrochemical behaviour of additives in conditions that simulate real copper, electrorefining. The behaviour of gelatine and thiourea was studied by applying different electrochemical methods, i.e. polarization resistance and voltametric measurements. In this study, individual galvanostatic electrolysis experiments were carried out for 120 hours. The organic additives were introduced to the electrolyte at certain intervals and their concentration was varied in the range &om zero to four ppm. An optical microscope was applied for the examination of copper cathode deposit microstructures. The results show that gelatine has a polarizing effect on the deposition potential of copper whereas even small amounts of thiourea depolarize the electrodeposition of copper. The maximum inhibitor efficiency of gelatine was obtained at a gelatine concentration of slightly lower than two ppm. When both gelatine and thiourea were present in the electrolyte, the depolarizing effect of thiourea exceeded completely the polarizing effect of gelatine. If chloride ions were added to gelatine and thiourea containing electrolyte, the electrochemical behaviour of the system was altered drastically. Chloride ions resulted in the prevailing of polarization effect caused by gelatine while the depolarizing effect of thiourea disappeared in this system. The polarizing effect of gelatine increased until chloride ion concentration of 30 ppm was reached. Also, the above electrochemical phenomena could be detected in the optical examination of copper deposit microstructure.

Jan 1, 1995

By M. S. Enders

The McDonald deposit is a volcanic-hosted epithermal gold resource that is estimated to contain 251,000 kg of gold in 375 Mt of ore at an average grade of 0.7 g/t gold. Phelps Dodge exploration geologists, working for the Seven-Up Pete Joint Venture, discovered the deposit in 1989. By the end of 1992, 494 drill holes for over 113,000 m of drilling, bulk sampling, soil geochemistry, geophysics, metallurgical testing, engineering, and environmental studies had been completed to support feasibility studies. The discovery of McDonald required vision, persistence, and commitment of everyone from the geologist on the drill rig to the senior management of the company.

Jan 1, 1995

By Alan Branham

The Mike deposit is a large, low grade, oxide, gold-copper system found at the intersection of two major faults that bound the Carlin Window, Eureka County, Nevada. Disseminated gold occurs within metamorphosed and hydrothermally altered silty limestone (Silurian-Devonian Roberts Mountains Formation), beneath 182 m (600 feet) of barren Tertiary sediments and tuffs. A supergene copper oxide blanket occurs beneath and locally overlaps the lower portion of the gold zone. Decalcification argillization, silicification, and brecciation are superimposed on earlier calcsilicate hornfels and marbles. Altered dikes and sills intrude the gold zone and are locally auriferous.

Jan 1, 1995

By P. G. Vikre

Several factors have caused less emphasis to be placed on geologic mapping in mineral exploration in the last 15 years. These include opportunities for "easy" discoveries of near surface gold and silver deposits in developed countries, and of base metal deposits as well in less developed countries, a decline of emphasis on geologic mapping in many universities, and a decline of useful mapping by government agencies in many areas. Geologic mapping is simply a way of recording geologic observations on volumes of rock larger than can be seen from one place. Since most geologic processes involve systems larger than this, mapping is also essential to understand the significance of observations made on smaller volumes of rock, such as thin sections and sample taken for chemical or isotopic analysis. To be useful, the observations recorded through geologic mapping are then interpreted to arrive at an understanding of the 3D geometry and geologic history of a volume of rock, which is used to direct mineral exploration, or any number of other purposes.

Jan 1, 1995

By D. E. Larson

The U.S. Bureau of Mines has developed a image analysis methodology to correlate the energy consumed during the grinding of an ore to the mineral liberation achieved. Energy consumption values are obtained using a laboratory-scale ball mill equipped with a torque sensor, and an automated image analyzer is used to determine the liberation present in ground products. By combining liberation information with energy consumption data an appraisal can be made of the energy required to liberate the mineral(s) of interest. Results of tests performed on a complex sulfide material determined the effects of grind duration on the liberation achieved and the energy efficiency.

Jan 1, 1995

By G. J. Karabin

The Boundary Element Method of Numerical Modeling has become an increasingly popular rock mechanics -mine design tool. It has been used by the Roof Control Division, Pittsburgh Safety and Health Technology Center, MSHA, to aid in the resolution of complex ground control problems since 1985. This paper will present an overview of an evolving simulation process and details of methods utilized to generate necessary coal, rock and gob input properties. Also included is a description of a Deterioration Index System that is used to link model output to observed mine conditions and two case studies to illustrate that process.

Jan 1, 1995

The purpose of this paper is to present validation studies of the mine-fire simulator using data gathered from an actual mine fire which occurred in November 1991 at the Pattiki Mine. To develop the model of the ventilation system with the fire in this validation study, the following adjustments were made: (1) flow and gas distribution in the entire ventilation network, and (2) fire parameters matching the data recorded by the monitoring system. After close correlations between simulation and real data were achieved, additional analysis of the ventilation system with the mine fire was performed. Presented and discussed in this paper are the following stages of the fire at the Pattiki Mine: (1) early fire (before the fire was detected), (2) preparation for and fire fighting with water, (3) fire sealing, and (4) fire extinguishing. This study evaluates the suitability of the computer software package for modeling underground fires. The paper also discusses the importance of the on-line monitoring system for the validation process.

Jan 1, 1995

By R. L. Godfrey

The Custom Coals advanced coal cleaning plant will be designed with a unique blending of existing and new processes to produce two types of compliance coals: Carefree Coal? and Self-Scrubbing Coal?. Carefree Coal will be produced by cleaning the coal in a proprietary dense media cyclone circuit utilizing fine magnetite to remove up to 90 percent of the pyritic sulfur and correspondingly greatly reduce the ash. While may utilities can achieve full S02 reduction compliance with Carefree Coal, others face higher sulfur reduction requirements due to the higher sulfur content of their existing fuel supplies. For these circumstances, a patented Self-Scrubbing Coal will be produced by taking Carefree Coal and pelletizing limestone-based additives with the finest fraction of the clean coal. These technologies will enable over 150 billion tons of non-compliance U.S. coal reserves to meet compliance requirements.

Jan 1, 1995

By T. Lee

Ongoing economic success for mining companies is dramatically enhanced when they really know what they are harvesting, such that they can accurately forecast their head grades for any time period in excess of a month. This is an uncommon experience. It is a very common scenario for resource/reserve estimates to overstate the concentration (grade). Grade is a critical input of revenue, and hence, it is to cashflow projections. With the current direction being taken by the legal climate, it is no longer adequate for directors to accept the resource/reserve estimates of experts at face value. This is because resource/reserve estimates are the foundation of primary mineral economic decisions. Directors of mining assets need to undertake their own due diligence analysis of these estimates, in the best interest of themselves, and the company's shareholders. In the light of the industry's past achievements, this is quite a challenge. This paper suggests a set of new objective tools for directors to undertake an overview of the unique commodity concentration pattern and assess associated economic dynamics of each mineralization. These tools allow the examination of global graphical trends that can be helpful to directors and others in undertaking due diligence of resource/reserve statements. Ensure that it smells right.

Jan 1, 1995

By T. Negeri

Flotation is the most efficient and preferred solid-solid separation method in mineral processing. However, enhanced production of high-grade concentrates at sufficiently high recovery still poses technological challenges to-day. A novel flotation method to produce final-grade concentrates from finely-ground ores in a single step is being developed and tested by CANMET. For the complex sulphide ores tested, grades are superior while recovery is considerably improved. Furthermore, concentrate production rates, at similar recoveries, are faster than for the conventional rougher-scavenger-cleaner configuration. This paper discusses the physical operating parameters affecting Cu-Zn flotation metallurgy.

Jan 1, 1995

By Marco Olper

The Italian company Engitec Impianti has developed a new electrochemical technology for the treatment of Electric Arc Furnace (EAF) flue dust generated in steel mini-mills. This process is based on a new and completely different concept from the Waeltz technology applied at present and allows, due to its modular nature, for an erection on the steel producer's site. Engitec Impianti spent US $700.000 constructing a 500 t/y throughput pilot plant at Pittini Group's Ferriere Nord mini-mill in Osoppo, Italy in order to demonstrate the process capabilities and obtain the data for a commercial plant design. The paper describes the pilot plant performances and the engineering criteria for a commercial unit of 10.000 t/y throughput. The feasibility study demonstrates a pay-back period of 3 - 4 years for the commercial plant.

Jan 1, 1995

By C. R. Tinsley

Valuations can be molded, twisted and misinterpreted. Cases of spurious scope setting; limits to the information or access by the valuer; difficulties with the lack of comparative valuations; inappropriate valuation methods and outright speculations are described. None should be accepted by an experienced, independent minerals valuer. The Australasian Institute of Mining and Metallurgy (TheAusIMM) is working on a Valmin Code for which a Manual of Best Practice and Valuation Guidelines may be developed.

Jan 1, 1995

By Joel L. Morrison

Wet bituminous coal fines from active and abandoned slurry impoundments are currently being examined as a recoverable feedstock for the production of coal water slurry fuel (CWSF). Preliminary analysis indicates that these coal fines can be converted into low solids, low viscosity CWSF with acceptable stability without the use of viscosity modifiers (dispersants) or stabilizers. Efforts are now underway to determine if the impounded coal fines can be economically cleaned by froth flotation to an ash level of < 12 wt. % and a total sulfur content of 1.2 wt. %.

Jan 1, 1995