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By Y. Prevost, D. Verhelst

"A computer-assisted process control system for the Noranda Process Reactor Wa5 installed at the Home smelter in 1991. Operating as an advisory tool for the furnace operators, and using a flexible oxygen balance as the basic building block of the computer program, the new control system has helped to reduce the variability in the grade of the matte produced by 50% . The smelter is currently operating at a 72% copper matte, with a standard deviation of between 1.0 and 1.3, while treating a wide range of concentrates, secondary materials and scrap. Enhanced process control has allowed for longer reactor campaigns, and improved stability of the converting operation.This paper reviews the feed classification and blending practice used at the smelter, outlines the strategy of the new computer control system, and summarizes the benefits realized since the implementation of the system in early 1990.IntroductionUntil 1989 the Noranda Home smelter operated as a multi furnace smelter, at one time having three hot-charge reverberatory furnaces, and finally operating with one wet-charge reverberatory furnace and one Noranda Process Reactor. In 1989 the final reverberatory furnace was closed and the Reactor became the sole smelting vessel, treating around 750 000 tonnes of concentrate, secondary materials, and scrap per year. At the time of the start-up of theNoranda Reactor in 1973, the vessel was capable of treating 750tonnes per day of a heterogeneous mixture of copper concentrates, fluxes and secondary materials to produce copper in one operation. Through process improvements, and the introduction of additional oxygen in 1982(pannell and Mackey, 1988), the daily tonnage increased to 1800 tonnes by 1988. The operation had also been changed to produce a high-grade matte instead of copper. Figure1 illustrates the main features of the reactor, a cylindrical vessel which is charged at one end and tapped at the other. The matteis subsequently processed through Peirce-Smith converters and anode furnaces before being cast into copper anodes. Figure 2 outlines the progressive increase in the furnace smelting capacity. Over this period the percentage of secondary materials, and scrap feeds also increased to approximately 110 000 tonnes per year, or 15% of the total new feed input (Bedard et al., 1991). Now operating wholly as a custom feed operation, the Home smelter can treat over 2200tonnes per day of new metal-bearing material."

Jan 1, 1993

By J. E. Lonergan

The in-pit placement of crushing and conveying equipment results in a flattening of the pit slope of a multiple-bench open pit mine. To maximize the economic benefit of lower haulage costs associated with in-pit conveying, one must minimize the cost of the flatter slope which is expressed in terms of additional stripping or tied up ore. A computer program that compares the tonnage aspects of various conveyor layouts will be discussed.

Jan 1, 1985

By M. R. Wormald

A real time data acquisition system has been developed for implementing standard radiometric analytical techniques, applied to the monitoring and control of mineral processing plants. The system uses standard ECB-bus microprocessors and peripherals, in conjunction with a specially designed nucleonic pulse ADC. It is being applied to the accurate on-line analysis of naturally-,occurring radioelements in processing plants, for example by simultaneously measuring the intensity of 1.46 MeV gamma-rays from the naturally-occurring radioisotope K-40, and the stream density by gamma-ray transmission of 662 keV gamma-rays. Gain stabilisation of the NaI(T1) scintillation detectors is maintained by the microprocessor in slave units, each of which may control up to four sample presentation systems. Data analysis - including corrections for bulk density, radioactive decay of the Cs-137 gamma-ray source, pulse pile-up, dead time and external background - is carried out in a master computer which is connected to the slave unit, and can be interfaced to the plant control computer via data links.

Jan 1, 1986

By M. P. Hoffman

The U.S. Bureau of Mines is developing a roof bolter with a computer-controlled drill head that will increase the safety of roof bolting in underground coal mines by allowing miners to be relocated to a safe area. To ensure secure anchorage, acceleration and strain data are broadcast from an instrumented drill steel to a data acquisition system. These data are analyzed, correlated, and transformed to pro-vide information about roof strata, then are sent to a supervisory computer executing National Institute of Standards and Technology's real-time control software. The supervisory computer sends setpoint commands to proportional-integral-derivative control loops to control drill thrust, position, revolutions per minute, and torque.

Jan 1, 1994

By P .. H. Grimley, N. Champigny

"Fourteen companies (Appendix) representing senior mining organizations in Canada were canvassed in order to assess: (1) the current usage and trends, and (2) the usefulness of computer applications in ore reserve estimation and grade control. The results of the questionnaire suggest that:• computers are unsurprisingly, predominant in the mining industry for calculating reserves and performing grade control;• time and cost savings are realized;• computer-based approaches are applicable to underground situations;• geological information is incorporated to the computerization process; and• computer usage does not hinder the collaboration of geologist and mining engineer.A clear need is identified for case histories comparing computer-calculated ore reserves and actual production data.IntroductionAmong the management and technical staff of some mining companies there is a perception that the application of computer based technology for the estimation of ore reserves and grade control, has as many drawbacks as benefits. Some of the objections raised against the utilization of computers for ore reserve estimation are that:• computer-based reserve models work for large open pit mines but not for underground situations;• computer-generated reserves ignore the geologist's knowledge base; they are strictly a number crunching exercise; and• the use of computers for ore reserves hinders collaboration between the geologist and mining engineer.In order to determine (I) the extent of current computer usage and future trends and (2) whether the objections noted above are borne out by experience, a number of senior Canadian mining companies were canvassed.The respondents were asked to provide:• an assessment of the importance of the computer in the ore reserve estimation and grade control process;• the level of involvement of individuals and staff groups with computer-based ore reserve estimation;• the advantages perceived and realized from the utilization of computer-based ore reserve approaches;• the current and future human resources requirements for the evaluation, implementation, maintenance and development of computer-based ore reserve systems;• the hardware and software resources presently used and planned; and• the developments needed to increase the use and acceptance of computer-based ore reserves."

Jan 1, 1990

By P Hanna

Following the Busang fiasco, more detailed guidelines were appended to the latest revision of the JORC Code released in September 1999 (JORC, 1999). Although the definitions and terminology essentially remained unchanged, the additional information in the guidelines has highlighted a number of issues for consideration by geologists undertaking computer-based resource estimations. The three main issues are:Data Integrity û details such as drilling and logging techniques, sampling procedures, assay tests, site visits, data recording and aggregation methods need to be considered. Geological Interpretation û is the Competent Person applying the appropriate software interpretation to the deposit in accordance with the regional setting. Are the correct computer-based tools being applied and are they producing the desired result (without compromise) to the satisfaction of the Competent Person? Modelling Technique û the importance of the relevant experience of the Competent Person not only in regard to the geology, but also with respect to the modelling algorithms and resource calculation methods of the computer software system involved. At the end of the day, it is essential that the Competent Person undertake a reality check on the resource estimation itself. They should also check that the borehole spacing is in accordance with the level of continuity for each critical parameter (such as structure, grade, impurities, etc) for which the resources are categorised.

Jan 1, 2000

By C. Gaubert, G. Bourassa

"The construction or rebuild process in the anode baking furnaces has been modeled with the software Rockwell Arena, in order to minimize the process cost and risk. The case study was focused on the sectional rebuild (""on the fly"") that needs a high coordination of the material inventory, the on-site personnel and the construction/production schedule. Multiple entities and resources were allocated for the different part of the process (in-furnace process, prefabrication, materials transportation, etc.). Logic flow charts and VBA macros were used to simulate the space utilization (including cranes utilization) and interaction with production. MS-Excel output files can show user-friendly results."

Jan 1, 2006

By H. Tiefel, M. Schneider, T. Neesse, J. Regler, J. Dueck, F. Donhauser

In practice the advantages of high-quality hydrocyclone separation are often reduced due to varying feed suspension properties, solids concentrations and particle size distributions. Control systems of large hydrocyclones are usually fitted with controllable underflow nozzles, which is not practical for small hydrocyclone batteries. Therefore, a new control system for a battery of hydrocyclones with a nominal diameter of 150 mm was invented at the LUR in cooperation with AKW Apparate und Verfahren GmbH & Co. KG. This process was developed for bentonite slurry regeneration associated with tunnel excavation using bentonite slurry as a transport aid and lubricant.

Jan 1, 2003

By Jerry L. Fuller

Fan performance graphs are generated by digital computer using two programs, RUN- FANS and FANPLOT. RUNFANS calculates fan performance data from stored specific-volume, specific-speed data for a given fan type with appropriate allowances for fan diameter, rotational speed and air density. FANPLOT accepts specifications for drawing the graph and accepts either user-supplied pressure-quantity data or RUNFANS- calculated data as input, Operational procedures for both programs are detailed and examples of their interactive query routines are included. The hardware necessary to generate the graphs is illustrated. Several hardcopy output options are discussed,

Jan 1, 1984

By Paul I. Eimon

Mineral exploration involves the selective collection, organization, evaluation, and interpretation of geologic and economic data. The sources for such data are original field observations and existing documented information of various types (publications, reports, maps, company files, etc.). As exploration data are accumulated, their storage, organization, indexing, and J retrieval is key to exploration progress. Initial use of computers by mineral exploration groups indicates that data can be meaningfully handled by machines. A computer system makes possible: 1) the storage, manipulation, collation, and selective retrieval of data; 2) the utilization of data banks developed by geologic service groups and available at relatively low cost; and 3) the retrieval of stored data more rapidly, completely, and effectively than by manual systems. Profitable utilization of these capabilities is conditioned by several factors, particularly by the information selected for the system data base and by the design of the computer system itself.

Jan 1, 1968

Having successfully applied computer techniques to open pit mining applications, many software developers are now using their skills to tackle the much harder areas of underground mine design, planning and production.Dramatic improvements in the performance to price ratio of hardware (including high resolution graphics screens), a better understanding of the techniques of surface and solids modelling (and their subsequent display), moves towards standard user interfaces and advanced concepts of representing grade distribution in the ore body have all contributed to the recent increase in underground mining software activity.This paper details the general requirements of a workable underground mining software system, providing a minimum checklist of desirable features and emphasises the importance of ease of use, flexibility and intuitive feel. Some relevant trends in hardware, software and application techniques are highlighted and comments made on areas which require further development or are only available in a small number of packages.Finally, a comment is made on the role of computer models to provide a unifying medium for tying together all aspects of underground design, planning and production.

Jan 1, 1992

By B. Willit, J. Martin

"Continued emphasis on water and energy conservation with less operator attention has created a need for more sophisticated cooling tower controls. A joint Betz/ASARCO project has produced a computerized water parameter controller and automated pumpless feed unit. Interfacing the unit via radio modem to the operator control room computer allows real time system status monitoring. Incorporating SPC principles to monitor and regulate all pertinent parameters yielded enhanced water control. This paper described the system design and present the results of a six month trial.BackgroundReducing operating costs and better manpower utilization are two of the largest concerns confronting maintenance managers today. At the ASARCO plant in Amarillo, a trial has been initiated to prove that it is possible to accomplish both of these objectives by using automated cooling tower control. The system is being adapted from a unit that was designed for continuously operating cooling towers in refineries and power plants by Betz Equipment Systems Division, a subsidiary of Betz Laboratories, Inc. The System l3000™ is designed to continually monitor conditions in the cooling system and to provide adjustments to the chemical balance for corrosion and deposition control. At Asarco, the unit was installed on the Rodline cooling system which operates on an intermittent basis.The primary justification for this project is to reduce costs of the five cooling systems in the plant. Current procedures require an operator to make visual checks every two hours on the five cooling towers as well as run lab tests on the water to insure proper treatment levels. This manpower can be better utilized by controlling the towers and collecting all the data available at one central location, in this case, the boiler house."

Jan 1, 1989

By J. A. Herbst

A state of the art computer simulation package, named UTAH-MODSIM is being developed. This package can run on a mainframe (eg. UNIVAC) as well as on a microcomputer (eg. IBM/PC with at least 512 kBytes of core memory). Friendliness was the major concern in developing this software. The user simply generates a complete flowsheet by presenting the flowsheet on a graphics terminal. This flowsheet defines the circuit to be simulated. With the minimum required data, the user can obtain a complete mass and water balances within a few minutes. Moreover, this package will provide scale-up and capital cost information of specified equipment relevant to design. In order to illustrate the utility of this software, three design examples are given. They are: a) A typical multistage crushing plant. b) A reverse closed grinding circuit comparing one stage with two stage classification. c) A standard closed grinding circuit suitable to liberate a specified fraction of chalcopyrite from a copper ore.

Jan 1, 1986

By J. S. Stachulak

Installation of a computerized mine monitoring and control system in two planned construction phases began in 1983. Phase one consisted of providing a central monitoring station located on surface for monitoring underground CO detection in Frood Mine's heated area. The implementation of this project annualized labour savings of $200,000. The cost of installation of an early fire warning system was $100,000. There are several CO sensor monitoring carbon monoxide trends through mine heated areas. To obtain an early warning, it is not good enough to know that a fire has started, but it is also necessary to know where the fire is located.

Jan 1, 1989

By Jonathan M. Berkoe

Design engineers and metallurgists have long recognized the need for better methods to calculate a wide range of fluid dynamic effects in smelters and hydro- metallurgical facilities. Examples can range from the capture of fume in the secondary hoods of a copper converter, to controlling the thermal effects of heat transfer resulting from metal and slag flows within a furnace. With the advent of relatively low-cost, high- speed computers and user-friendly, commercially available computerized fluid dynamic (CFD) programs, these calculations can now be made. Use of CFD increased the understanding of both hot gas and molten flows in smelter facilities and has already led to design improvements in converter fume control hoods as well as improved management of heat transfer in electric furnaces. This paper will present two representative CFD applications to metals industry facilities. To date, Bechtel has implemented CFD results on four continents.

Jan 1, 1999

By C. Jardine

The concept of the system is to minimize costly unscheduled breakdowns of equipment by replacing components earlier than their "life" expectancy. Periodic unit services are scheduled according to pre-set constraints. Service sheets are generated by matching a job and component master listing based on assigned cyclic component lives. The system can provide accountability of all man-hours reported and history information can be selectively retrieved. By reducing unscheduled equipment shutdowns, this system allows for better utilization of manpower and an overall improvement in equipment reliability and availability.

Jan 1, 1979

By C. Jardine, D. Freudenreich

The system concept is to minimize costly unscheduled equipment breakdowns by replacing components earlier than their life expectancy. Periodic unit services are scheduled according to preset constraints. Service sheets are generated by matching a job and component master listing based on assigned cyclic component lives. The system can account for all man-hours reported, and history information can be selectively retrieved. By reducing unscheduled equipment shutdowns, this system allows for better manpower utilization and an overall improvement in equipment reliability and availability.

Jan 1, 1982

Monitoring systems can have numerous uses in the mine. They can aid in the efficient management of the mine by providing environmental trend data, production and maintenance control, and communications. In some cases, they can provide justification to petition the Mine Safety and Health Administration (MSHA) fog a variance of one of the mandatory safety standards. They may also increase the gross revenues of the mine by increasing the amount of coal produced or increase profits by reducing the cost of producing that coal. No single system will satisfy the requirement of all mines. Some may require simple hard-wired status-reporting systems; others, multipurpose computer-based systems that collect, analyze, and store data and perhaps control some mine functions. Even though systems vary in complexity, they are all composed of three functional components. The first component is sensors that measure the environmental or production parameters and produce an electrical signal that is fed into the telemetry. The second is telemetry devices that receive the signal from the sensors and transmit it in either analog or digital format to the third com¬ponent, analysis and display equipment. This equipment receives the transmitted signal and either stores it for later analysis or displays it. The analysis-display equipment ranges from simple strip chart recorders with preset alarms to computers, cathode-ray tubes (CRT's), and line printers that can also provide production reports. 4.2 Uses of a Mine Monitoring System A list of potential uses for mine monitoring systems, including both production-related functions and those related to health and safety, was used to develop a questionnaire. It was presented to representatives of the mining community to determine their current monitoring priorities. The responses indicated that the industry's priorities fall into the following two categories: First priority- Production and haulage Maintenance Second priority- Ventilation Communication Fire monitoring Personnel The survey shows that production-oriented systems were the most appealing to the questionnaire respondents. Since even small improvements in production efficiency and maintenance can have a large financial impact, the desirability of monitoring systems that focus on these areas is understandable. The results are summarized in table 4-1. The function that scored 100 was viewed as the most beneficial monitoring function.

Jan 1, 1984

By G. H. Blackwell

Sequences in open pit mining must be planned and regularly revised to incorporate changes in the variables which affect profitability. Interactive computer planning with colour graphic facilities is an effective tool for this purpose in the short and medium term. An interactive computer planning system for medium-size, low grade porphyry copper-molybdenum open pits is described. The planning system proved especially valuable during the critical stages of pushback mining when deep, inner pit ore was nearly depleted and the erratic grades of the next pushback provided ore and marginal material at a time of depressed metal prices.

Jan 8, 1993

By A. E. Koski

This paper will review recent developments in the area of mine planning at the Empire Mine. It illustrates how one of the largest iron mines in North America has adapted computerized mine planning to meet the unique requirements of their mining operation.

Jan 1, 1994