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By P Brown, M Nagarajan, A Green, P Dare-Bryan

Coal loss is an important issue at many coalmines, with losses of five per cent being common. The type of loss varies from mine to mine but is dependent on mine strata, the drilling and blasting processes applied and the mining method used. Typical coal loss mechanisms from the drill and blast process are coal roof damage and edge loss. Usually a reduction in coal loss is in direct competition with the need to provide material that is well-fragmented and a muck pile that has the required cast percentage. These competing issues were addressed over a two-year period at a mine in the New South Wales Coalfields by implementing a five-step approach. This was centred around building an understanding of the coal loss mechanisms utilising proprietary heave- modelling software, measuring coal losses by comparing survey to drill and/or gamma logs and implementing appropriate coal loss reduction processes. The end result exceeded expectations with a 95 per cent reduction in coal loss. Mine excavation productivity was maintained and coal loss minimised to less than one per cent of the in situ coal block.CITATION:Nagarajan, M, Green, A, Brown, P and Dare-Bryan, P, 2015. Managing coal loss using blast models and field measurement, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 429–436 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

The control objectives and constraints for grinding circuits are ana- lysed, taking a single-stage ballmill-cyclone circuit as an example. The design of a hierarchical modular control system is described, for implemen- tation on modern microprocessor-based control systems. Product sizing measurement is identified as a problem area, and a new approach to product sizing inference, from on-line cyclone feed and overflow measure- ments, is presented. The procedure over-comes several practical difficulties of a previously proposed inferential method and is therefore expected to find application in more advanced grinding circuit control systems.

Jan 1, 1988

By J G Bastias

It is sometimes necessary to resort to extremes in order to call attention to something that is pertinent to safety in mining. When some of the experts in occupational safety talk about this topic, they usually refer to a 'regulation' established by the Romans which stated that, due to the health hazards, usually death, no Romans but only slaves should work in mining. Since the time of the Roman Empire, a lot of ground has been covered in the field of mine safety. Nowadays, it can be said that occupational safety is being seriously addressed, with the result that the number of mining accidents has reduced dramatically, fatalities in this industry are less frequent, and the rate of accidents compared with other activities, such as construction or fanning, is low. This achievement has been possible initially through government legislation and by procedures established by the mining companies themselves. However, the dilemma for government is whether to regulate and if so, how much. It is pleasing to observe that most companies are establishing working procedures which conform with new government legislation, placing strong emphasis on the duty of care for mine employees. There will always be some regulatory aspects of legislation, and perhaps the best example of this is in the use of mine hoists where there are no international or Australian standards, and the regulations applied are of an empirical nature that err on the side of safety.

Jan 1, 1994

By R Burgess-Limerick, D Lynas

A number of standards and guidance materials currently exist to assist equipment designers. The ISO process, however, is a formal process and change often lags behind technology development. In some cases, this may result in weak or ineffective standards that need to be written in general terms to accommodate future technology developments, meaning some standards may only establish minimum requirements and not be overly helpful to equipment designers, in particular when designing for workforce diversity and inclusivity. By contrast, advisory information as issued by various mining regulatory bodies is able to respond more quickly to changes in technology. Standards do however have a safety and productivity focus providing design consistency between equipment manufacturers, a basis for auditing purposes, assistance in mining regulation and compliance, and in the development and application of safety management systems. As an example of challenges facing equipment designers, ISO3411 (2020) provides data approximating the 5th, 50th and 95th percentile of the ‘earth-moving machinery operator population’ for numerous static dimensions relevant to the design of earth-moving equipment. These data are then utilised in ISO6682 (2020) to provide recommendations regarding the location of controls. Attempting to utilise the data provided in ISO3411 (or other sources of static anthropometric data) creates further challenges for equipment designers, in that reference percentiles is problematic for design purposes. There is no ‘5th or 95th percentile operator’ as individuals vary along each dimension (Robinette and Hudson, 2006). Although dimensions have some degrees of correlation, when multiple dimensions are considered, the range of individuals which fall within a given range on all dimensions reduces substantially. For example, only about 82 per cent of individuals in a population will fall within the 5th to 95th percentile ranges for both height and weight. The more dimensions are considered, the smaller the range of people who actually ‘fit’ the description.

Apr 16, 2024

By D Kent, R Paine

"Automated mining systems are increasingly being seen as a key requirement for a productive mining operation in the future. The importance of an integrated communication network infrastructure to support such systems is growing.This paper outlines the introduction of automated mining systems in large conventional mines as well as their growing role in block cave mines currently operating or being developed. The paper will then focus on a case study of how the communication infrastructure is fundamental to the operation of such systems and explain why the resultant communication networks require much more than just increased bandwidth (data capacity) to properly support the automation system within the overall mine operation.Mining operations already embarking down this road are discovering that the required network must be based on a true enterprise level architecture to not only enable the mine’s current plans for remote and automated mining, but also provide a scalable and integrated platform for future developments and requirements. The emerging issues for the communication network to truly support automation systems include: increased complexities of operating and maintaining multiple networks integration issues with disparate systems problems with reporting particularly as demands for corporate reporting and compatibility with enterprise systems become the norm ongoing management challenges, which will only increase with the proliferation of new technologies.The paper will explore how certain mining operations are addressing this by adopting a long-term strategy for automation deployment, which includes laying the necessary foundation architecture to meet their current requirements, while supporting their future visions for the fully automated mine.CITATION:Paine, R and Kent, D, 2014. Developing the foundation communication infrastructure to support remote and automated mining initiatives in underground mines, in Proceedings 12th AusIMM Underground Operators’ Conference 2014, pp 151–158 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 24, 2014

From a personal view that encompasses both research and assessment of major projects the author outlines the two competitive pressures that will force more rather than less metallurgy viz the increasing difficulty in purchasing the latest overseas developments and environmental concerns. This paper then goes on to argue that Australian metallurgy or more precisely process engineering may be in a unique position to deliver the required results.

Jan 1, 1993

By S McKnight, L Koroznikova, J Begelhole

"This paper outlines a simple methodology for iron ore characterisation. Iron ores commonly contain a range of iron oxides with varying iron content along with generally minor quantities of lighter silicate gangue phases, giving rise to density variations. Companies tend to rely on heavy liquid separation (HLS) in the evaluation of samples arising from exploration, mining or metallurgical processes. Heavy suspension separation (HSS), a simple laboratory technique of density fractionation, employing suspensions of fine tungsten carbide (WC) particles in lithium heteropolytungstate (LST) solutions, can be used in the evaluation of iron ore.As part of Arrium Mining’s program to improve its knowledge of ore types being processed in two hematite ore beneficiation plants (OBP), metallurgical evaluation of hematite feed and geometallurgical evaluation for the OBPs has become a major focus.Metallurgical evaluation of the hematite ore ultra-fine size fraction, formally treated as waste but now upgraded by HSS, is a part of Arrium’s program to improve recovery.The HLS method for iron ore characterisation is not generally used as part of routine iron ore feed metallurgical evaluation due to the expense, toxicity and time-consuming nature of the technique. Results show that the HSS method for iron ore characterisation can achieve low-cost, low-toxic separation and can be used on-site to improve turnaround time of results (Begelhole, Jasper and Koroznikova, 2013).Arrium have applied this technique successfully for the past three years to progress process improvement for the two OBP as well as to assist Arrium’s on-site laboratory services, Bureau Veritas in Whyalla.The main objective of this program has been to further develop the HSS procedures using a low-toxicity, high specific gravity (SG) suspension; LST and WC as the dense medium for metallurgical evaluation of ultra-fines.A suspension of a particular density will separate iron ore into two products: a sink fraction (denser iron oxide – hydroxide particles) and float fraction (silicate – iron ore composite particles). A theoretical grade and mass recovery can be calculated, and a grade – mass recovery curve can be constructed for iron.Metallurgical evaluation of the plant feed ultra-fine size fractions are used to improve efficiency of an upgrading plant process. This type of characterisation can be used to prepare feed piles of known processing characteristics, or to benchmark the performance of the process against what can be theoretically achieved.CITATION:Koroznikova, L, Begelhole, J and McKnight, S, 2016. Characterisation of Low-grade Hematite Ore Ultra-fine Size Fraction Particles by Heavy Suspension, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 327–334 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By Windsor C. R, Thompson A, Bywater S

A new high tensile strength, steel cable, that may be grouted into boreholes has been developed for use as rode reinforcement. The manufacturing technique produces a birdcage pattern in which the cross section varies along the length of the cable. The load transfer from cement grouts to birdcage cables has been demonstrated in laboratory tests to be better than that of standard 15.2 mm diameter seven wire cables. The manufacturing process also allows for a wide range of capacities which may be specified by design engineers. The various birdcage cable configurations have been applied as rock reinforcement in a number of Australian underground and surface mines.

Jan 1, 1990

By M Fylak, R Wenda

Advanced preparation techniques open new ways for SEM and X-ray diffraction (XRD) investigations on hydrating cementitious systems. In this paper the early time hydration of Portland cement is studied with advanced cryo scanning electron microscopy techniques in combination with in situ X-ray diffraction and heat-flow calorimetry. The application of preparation techniques and analytical methods to Portland cement hydration are presented and discussed. Some aspects of hydration reactions are focused. The reaction products of the first minutes, changes in ettringite morphology, AFm formation during the deceleration period and the visualisation of C-S-H microstructures were special points of interest. X-ray diffraction analyses and Cryo-SEM images gave essential information about phase development, reaction kinetics, microstructure and morphology of hydration products. Portlandite, AFt and AFm phases were detected by in situ XRD. Cryo-SEM analyses enabled high resolution imaging and EDX-analyses of cement particles and reaction products. The results of the different analytical methods were compared to obtain detailed information about crystallisation processes and microstructural development during the first three days of Portland cement hydration.

Jan 1, 2008

By Pinczewski WV, Nowak LP, Tanzil WBU, Jenkins DR, McCarthy MJ

An experimental and theoretical study has been made of the drainage behaviour of two-dimensional packed beds drained from an outlet in the sidewall of the bed in order to identify the fundamental me- chanisms involved. Under these conditions a grad- ient develops in the air-liquid interface in the direction of flow with the interface tilting towards the outlet. This results in a significant volume of liquid being retained in the packing on completion of draining when the interface first reaches the bed outlet. Residual liquid volume and the shape of the air-liquid interface as a function of time were det- ermined experimentally in a two-dimensional packed bed where the packing consisted of glass spheres ranging in size from 0.6 to 10 mm dia. and the bed was drained at superficial liquid velocities rang- ing from 0.007 to 0.32cm/s. The test liquids used were water, glycerine/water solutions and kerosene resulting in a viscosity range of 1 to 10 mPa.s and a surface tension range of 0.0243 to 0.072 N/m. Assuming laminar flow within the bed, a compu- tational model was developed to predict both the liquid residual ratio and the temporal evolution of the drainage profile within the bed. The computed results were in good agreement with the experimental data over the entire range of conditions invest- igated. the computational model was used to estimate the relative importance of the effects of changes in hearth conditions on residual slag volume for typ- ical blast furnace operating conditions. On the basis of the computed results it is concluded that coke quality is a major parameter affecting hearth drainage performance.

Jan 1, 1981

By Carter J. P

A two year study into the effects of coal mining induced subsidence on cliff lines was undertaken by the Department of Mineral Resources with the support of a grant under the National Energy Research, Development and Demonstration Program. A new monitoring technique, using an Electronic Distance Meter and acrylic reflectors attached to the cliffs, provided safety for the surveyors and extensive and accurate three dimensional displacement data on the movement of the cliffs as they were being undermined. The study report included many graphs showing the measured vertical and horizontal displacements, differential subsidence, tilts and strains and included analysis of these movements with various parameters, such as, seam thickness, depth of cover and distances between the reflectors, longwall face and the edge of the chain pillar. Some of these graphs are presented in this paper and could be used, with caution, to predict subsidence movements around other cliff lines, after allowing for differences in geology and mining layout. A mechanism is suggested as an explanation for the observed high horizontal movements around the cliff lines. Sixteen percent of the overall lengths of cliffs that were undermined during the monitoring study fell and the contributions of various factors that appeared to influence the cliff falls are discussed. It is concluded that no single factor dominated as the major cause of the cliff falls and, often, many factors combined to cause cliff face instability.

Jan 1, 1992

By Y Gu

The Mineral Liberation Analyser (MLA) employs the technologies of scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The use of backscattered electron images to define phase boundaries produces very high resolution image analysis and subsequently detailed and accurate particle images and data output. The mineralogy, elemental deportment, grain size, liberation characteristics and mineral associations of a large number of samples can be described. The MLA uses a comprehensive set of analysis methods to meet a wide range of applications. The data from ore characteristion projects completed during feasibility studies are important aids for effective plant design. The MLA can be used to establish variation in the mineralogy of an orebody, identify and quantify the deportment of deleterious elements, and provide valuable information to support comminution and flotation test work. In established plants the MLA data is an important component of plant survey work and monthly composite samples. Changes in feed characteristics and/or operating conditions can be monitored and solutions to any deterioration in recovery and grade performance found. The MLA has extensive applications in the minerals industry. Rare and precious metal samples can be accurately measured using high-resolution grey-scale images. Several new measurement techniques have been developed to perform rapid searches of a large number of samples to provide efficient and accurate analyses of fine-grain, low concentrate material. Quantifying the mineral variability in mineral sands operations is essential to maximising grades and recovery. The MLA produces particle-based data on density, mineralogy, size and shape and has developed measurement techniques to provide the elemental quantification required for the characterisation of these deposits. Nickel sulfide ores can be analysed to provide modal mineralogy, elemental deportment and liberation and locking data. The low-grade and variable nickel mineralogy of these deposits makes the use of quantitative mineralogy an essential component of maximising returns. Coarse particle measurements preserve the in situ textures of ores and support flotation and breakage test work for feasibility studies. The deportment of penalty and bonus elements can be quantified and the association and grain-size data can be used to identify potential separation issues.

Jan 1, 2006

By G Sartor, A Rich, D Grimsey, R Forzatti, M White

An in-depth process model was developed for the pyrometallurgical, off-gas systems and water balance of the Kalgoorlie Nickel Smelter. This model was used to assess plant capacity with changing concentrate grades, increased throughput and tighter environmental emissions under a range of potential future operating conditions. Comparison of modelled results allowed for flow sheet optimisation across a range of metrics including sustainability, processing capacity and costs. Process modelling software, METSIM® (ver 2020.06 by METSIM International), was used to simulate the flash furnace, integrated electric slag cleaning furnace, Pierce-Smith converters, matte granulation, waste heat boiler, hot gas handling equipment, wet gas cleaning plant and acid plant. The METSIM® model was divided into three separate, yet interconnected models: metals, off-gas and water balancing. This allowed for improved modelling efficiency and traceability while minimising manual error. The METSIM® model was supported by inputs from other specialised software. Chemical thermodynamics software, FactSage™ (ver 8.2 by GTT Technologies), was used to establish relationships for the flash furnace fluxing strategy and determine the operating temperature. Arena® (ver 16.0 by Rockwell Automation), a discrete event modelling software, was used to simulate material movements within the aisle as well as Pierce-Smith converter operation, allowing for integration with upstream and downstream systems. A dynamic data exchange (DDE) was used to connect the results of each software package, interfacing through Excel® (version 4203 by Microsoft). The integration between models provided a streamlined approach to test capacity, bottlenecks, water consumption and emissions under a range of operating conditions, enabling a more robust process. Further downstream modelling techniques were used to assess mechanical equipment. METSIM® outputs provided key parameters for combustion assessments using computational fluid dynamics and finite element analysis for the furnace mechanical design.

Aug 21, 2024

By Dredge K, Becker G

The successful dissolution of the valuable metal components of a solid phase is often a basic requirement for a successful hydrometallurgical treatment process. Sulphide concentrates are often an intermediate product in the production of refined metals. These concentrates need to be further processed to realise the contained metal values in a useful form. Pyrometallurgical techniques have tended to dominate, at least the initial treatment of metal sulphide concentrates. The technology described, Activox«, has been developed specifically for the hydrometallurgical treatment of these sulphide mineral concentrates, in particular those containing copper, nickel or gold. The Activox« dissolution technology coupled with the use of existing, or newly developed, downstream processing techniques, offers alternative processing options for the recovery of full value, saleable metal products. The technology is suitable for application down to relatively small scales opening up the opportunity for on-site production of metals even at modest scale mining Operations.

Jan 1, 1995

By M Boon, M Franklin

This paper outlines the journey of cultural maturation and management system development at the Mt Rawdon (MRO) gold mine from its acquisition by Evolution Mining Limited (Evolution) in late 2011 to 2016.Evolution embarked upon a series of projects that aimed to improve the operational consistency and implementation of change on-site, while leveraging off the existing strengths of the operation. This document describes the gaps that were identified, the processes used to close them, and the resulting cultural change and production outcomes, with a specific focus on how to optimise the culture at any mining operation.MRO had a history of four owners in less than three years when it became a key asset of Evolution. The site leadership team (SLT) decided to influence the culture at MRO by reviewing and upgrading the existing management processes.The first priority was to improve transparency and collaboration at the SLT level, followed by improving competency in project management. The next phase was to strengthen the internal communication using a deliberately designed network of meetings, communication screens and other initiatives. Once there was some traction, the focus moved toward increasing production volume and decreasing cost per unit by improving short-term planning and execution capability. Together with other initiatives, this resulted in improved collaboration between all functions, which in turn netted over 37 per cent mining production uplift.Following solid success, a process of prioritisation and alignment management was implemented. This supported the ‘Mine to Mill one operation’ ideal and allowed the SLT to decide month-by-month what actions were to be prioritised. These priorities incorporated production realities and longer term imperatives of the balanced business plan.Much of this work was completed during a period of declining gold prices and a relentlessly strong Australian dollar, making it difficult to justify spending money on improvement projects. This work proved critical for the operation’s long-term survival.CITATION:Boon, M and Franklin, M, 2016. Improving consistency of delivery at Mt Rawdon Operation, in Proceedings International Mine Management Conference, pp 305-320 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By D Thornton, R Hodson, D Sprott

Blast fragmentation size distribution and thus blast design have been found to have a direct impact on the load and haul cycle through excavator dig time and bucket payload. Previous studies have demonstrated that by reducing the excavator dig time and increasing bucket payload, significant improvements can be made in both productivity and unit cost. Simulation work reported in the literature indicates that a 20 per cent improvement in dig time may result in only a three per cent improvement in load and haul productivity and unit cost. At the same time, a ten per cent improvement in bucket payload will directly translate to a ten per cent improvement in load and haul productivity and unit cost. Based upon these findings, extensive laboratory and field work have been undertaken in the past to correlate blast fragmentation distribution to bucket payload. In contrast, the literature reports limited studies quantifying the impact of blast fragmentation on excavator dig time. Field work was conducted at Placer Dome Asia PacificÆs Granny Smith Mine (Wallaby Pit) in Western Australia, concentrating on quantifying the impact of blast fragmentation on the dig time of a Liebherr 994 hydraulic excavator (shovel attachment with 14 m3 bucket). Fragmentation was assessed for each truck load of material using the Split Desktop system, while the excavator cycle analysis was conducted manually. Measured fragmentation P80 (fragment size at which 80 per cent of material passes) values ranged from 200 mm to 1200 mm. The field study investigated the impact of various fragmentation parameters (P20, P50, P80, cumulative per cent passing 250 mm size fraction, and uniformity index) on the average and total dig times. The results indicate that the fragmentation P80 provides the best correlation to average dig time (total dig time divided by the number of bucket passes to load a truck). The total dig time was found to be dependant upon the fragmentation P80 and the number of bucket passes to fill a truck. Monte Carlo simulation results, based upon these relationships, indicate a 26 per cent improvement in average dig time and a 12 per cent to 46 per cent improvement in total dig time (bucket passes ranging from 4 to 8), with a change in fragmentation P80 from 600 mm to 200 mm.

Jan 1, 2003

By L Neems

In conjunction with Orica Explosives, Worsley Alumina have managed a program of continuous improvement to their cap rock blasting over the last two years. Blasting conditions are challenging because of the hard and shallow nature of the material. Blasting costs must be controlled and the environmental consideration of noise and dust is critical. Worsley have sought to determine the optimum balance between drilling and blasting costs and fragmentation. As the cap rock has few inherent weaknesses, loader productivity is strongly controlled by the degree of fragmentation from blasting. The optimum blasting solution is also constrained by maintaining airblast levels at the surrounding residences below 115 dBL . The major blast design parameters optimised during the program were stemming type, stemming length, powder factor and blasthole diameter. A series of carefully managed trial blasts were fired during 1997 and 1998 to quantify the effect of these parameters. Fragmentation was digitally measured using OricaÆs Powerseive G technique. Shovel productivity, airblast levels and blasting costs were also quantified. As a result of the project, Worsley now have an increased knowledge of the key parameters driving blast performance, and their consequent impact on downstream processes, the environment and total mining cost.

Jan 1, 1999

By J Li, H Hooi, D Payne

Caval Ridge Mine (CVM) is one of the newly established open-cut coal mines of BHP in Queensland, where no tailings dam is planned to be built in order to minimise environmental impacts from mining activities. The waste streams from the Coal Handling and Processing Plant, including fine tailings dewatered by belt filter presses, coarse rejects, and mixed plant rejects, are co-disposed within waste dumps built with pre-strip and dragline spoils. Due to high rejects output (35 – 60% of feed) and low spoil to reject ratio (< 5) the large quantities of rejects bring significant geotechnical and operational challenges to CVM, which are exacerbated by increasing annual production rates and additional rejects from washing coal from an adjacent mine. Further in-house geotechnical review commenced in mid-2014 based on the initial geotechnical studies during the project stage of CVM between 2011 and 2013. The outcomes have enabled rejects disposal at CVM by constructing large belt filtered tailings cells, coarse rejects only dumps, and co-disposal of the mixed plant rejects at dump tip-heads. This paper presents the rejects disposal strategies at CVM from both technical and operational aspects. It also discusses future projects for belt filtered tailings moisture reduction including assessment of tailings clay mineralogy, as well as mixed plant reject co-disposal verification and optimisation.CITATION:Li, J, Payne, D and Hooi, H, 2018. Plant rejects disposal strategies applied at Caval Ridge open cut coal mine, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 50–60 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

The paper presents an overview of the mining industry of Papua New Guinea. Although the Bougainville problem is still unresolved, new mines like Ok Tedi, Misima and Porgera, which have come on stream during recent past, have raised hopes of sustained growth period in the industry. Kutubu Oilfield is also being developed in the Southern Highlands and the oil production has commenced from July 1992. Government revenue from these mega projects will increase five-fold during 1993 and 1994. A new mine which is being planned is the fabulous Lihir Deposit, on an island renowned to be full of gold. Gold occurs within a volcano which still contains high temperature ground water because the system which created the deposit is still geothermally active.In Papua New Guinea, problems of environmental management are far easier to tackle than those of a socio-political and economic nature involving compensation payments to the landowners and the distribution of royalties and taxes between the national and provincial governments. At the socio-political level, the country has not been able to resolve the problems of land rights versus mining rights. Whenever mining starts in a big way, it raises people's expectations to a very high level, which then becomes the focal point of dispute between landowners, provincial governments, national government and mining companies. A new system called 'Forum' has been tried to bring all parties together and son out the issues. The system appears to be working well in new mines like Ok Icdi, Porgera, Misima and Kutubu Oilfields.

Jan 1, 1993

Recent work on computerised mineral resource databases at the Institute of Geological and Nuclear Sciences Limited has concentrated on the development of the GERM, REGCHEM, and MINLIT databases, and their integration in a Geographic Information System using MapInfo software on an IBM-compatible microcomputer local area network. GERM (GEological Resource Map) is a mineral deposit inventory with national coverage and more than 10 300 entries. REGCHEM (REGional Exploration GeoCHEMistry) is a database of stream sediment analyses from open-file mining company reports, containing more than 14 000 sample sites from the Coromandel and west Nelson regions. MINLIT (MINeral LITerature bibliography) is an annotated bibliography of literature on topics relating to the exploration and geology of mineral deposits in New Zealand, and includes more than 5000 entries for published books and papers, and unpublished mining company reports, university theses, and government reports. Master sets of GERM and MINLIT continue to be maintained on a VAX mainframe network but REGCHEM is operated only in the PC environment using the Microsoft ACCESS database management system software.

Jan 1, 1993