Search Documents

By Lynn B. Hales, Randy A. Ynchausti

Object-oriented technologies have been developed to more closely model the way we think about the world and our natural approach to solving problems. Higher levels of abstraction, generalization and classification are benefits of an object-oriented approach. Object-oriented programming, design, and expert systems are part of this technology which is shaping the future of real-time supervisory control. Goals of real-time supervisory control systems include: minimizing variations in process operations, improving efficiency, maximizing production, and implementing procedures for starting and stopping the process. Incorporating object-oriented technology in design, development and implementation of real-time supervisory control systems provides new opportunities for these tasks. This paper discusses some of the opportunities and challenges of implementing real- time supervisory control using an object-oriented expert system for a rougher flotation circuit

Jan 1, 1993

By Kanaan Hanna

A joint research program between the U.S. Department of the Interior's Bureau of Mines and Cyprus-Yampa Valley Coal Company is being conducted at the Foidel Creek Mine, Oak Creek, Colorado. This program goal is to study the effects of state-of-the-art, high-speed, automated longwall mining on health and safety, and primarily, ground stability under various geological conditions. The Bureau installed an automated data monitoring system, known as the Ground Control Management System (GCMS), to monitor in real-time the effect of rapid mining on pillar and face loading, stress redistribution in and around the longwall panel, and caving characteristics of the roof. The Bureau's GCMS, combined with the company's existing monitoring systems, which include environmental monitoring, a computer programmable conveyor belt system, and gamma ray roof control thickness indicators, has been effectively used to improve safety at the face, increase productivity, and reduce production costs.

Jan 1, 1991

By George Munro

New Zealand is a small, almost pristinely pure country environmentally speaking. It is blessed with an abundance of clear waterways, lush green vegetation and fresh clean air. It is a country in which agriculture and forestry predominate, and mining developments have to be introduced prepared to answer in considerable detail the question "How will this proposal affect the New Zealand environment as we know it today". Those who make the legislation have the difficult problem of establishing standards at a level which will maintain as far as possible the status quo without unduly inhibiting the developments currently approaching the starting line. We have been fortunate in some sense in that since the demise of the early gold rush days by the 1920's, little mineralisation of a complex nature has been uncovered in New Zealand. Coal fields have been developed in the central North Island, and on the West Coast and Southland regions of the South Island. A ban on large scale open cast mines in the Coromandel area has restricted mining in that highly prospective area, although three large gold prospects have got underway elsewhere in the last three years. There is no other ore processing being undertaken at present. Some recent proposals involving lead, gold and silver in complex arseno­ sulphides have failed to get the necessary approvals and have been discarded. Our ore processing problems are therefore straightforward ones, and confine themselves to acid drainage, mercury handling and disposal, and cyanide.

Jan 1, 1991

By Richard Dunmore

Most coal seams in the United Kingdom contain firedamp, some of which is released into the ventilating airways as the strata around a working relax. The close sequence of seams in carboniferous strata is usually such that seams in adjacent roof and floor strata are also disturbed and potentially large quantities of firedamp can enter the workings from these sources. Since emission depends on the disturbance rate of the seams, higher coal production rates associated with increased mechanisation in the colliery accentuate the problem. Firedamp concentrations in UK underground workings are subject to statutory regulations1. To enable production to continue uninterrupted and in safety the problem is tackled by ventilation engineers by the provision of adequate ventilation in the airway and by the technique of firedamp drainage. In the UK the latter usually takes the form of cross-measure boreholes in roof strata, and increasingly also in floor strata, drilled from the gateroads, especially from return airways. In this way firedamp emitted from disturbed seams in adjacent strata can be extracted directly to the surface or to some safe position outbye, and the airways of the working district are not contaminated. Despite the use of firedamp drainage, considerable quantities of firedamp enter the ventilation air- stream and the concentration levels may be seen to be related to the coal production activites in the district. Figure 1 shows a typical recording of methane concentration obtained by a BM1 methanometer at a position outbye in a return gate where firedamp drainage was operating. The general rise in level throughout the working week may be seen, together with peaks occurring during production shifts and the gradual decay of emission over the weekend. In view of the fact that ventilation and firedamp drainage contribute a considerable proportion to the operating costs of the colliery, it is essential that the ventilation and firedamp drainage requirements be calculated as accurately as possible at the planning stage of the working. In the past the ventilation engineer has had to rely heavily on experience in neighbouring workings but with the development of mines in previously unworked areas there is clearly a need for a methodical approach to meet the requirements of planning. The work described in this paper represents such an approach and it is hoped that successful development and application of the method of prediction will lead to the widespread adoption of a routine procedure. The current development of a method of prediction of firedamp emission into longwall workings is based on the theoretical treatment of gas emission from coal seams proposed by Airey2 in 1971, which was based on his study of gas emission from broken coal 3 which was published in 1968. In common with other experimental methods of prediction, the method enables a calculation to be made of the total make of gas emitted from all sources of gas in the strata per tonne of mined coal.

Jan 1, 1980

The feasibility of exploiting a mineral deposit by developing a surface mine is closely related to the environmental protection and land reclamation costs. This issue has utmost importance for West Macedonia Lignite Centre (WMLC) of Greece, where there is still a lot of interest for opening of new mines and for further development of the existing open-pits. The decision-making process in these cases can be based on a decision tree that takes into consideration the various cost components of environmental management, the alternative solutions, the environmental permits and the cost reports of environmental management actions carried out so far. Moreover, the mine planning procedure is affected indirectly by numerous uncertain environmental and socioeconomic parameters, such as the delays caused by the bureaucratic procedures and the settlement of arguments in the Court.

Jan 1, 2006

By J. Kulczycka

The concept of sustainable development is be-coming present in the policies of increasing number of industries and governments. The complexity affects not only production aspects, but has also special relevance for environmental decision making. Not only producers are re-evaluating the services they expect from the environment and concomitantly increasing their willingness to sacrifice other consumption in favour of enhanced environmental services, but the character of environmental issues is becoming more complex as well. Incomplete information, uncertainty, system wide change, trans-frontier impacts, current causes that have far reaching future effects, irreversibility, and possibilities of catastrophic change all complicate the environmental decision making process. Non-ferrous metals production, due to a relatively low level of metals content in ore, results in generating huge amounts of tailings, exceeding usually 90% of the mine output. They must be stored in special facilities, which have the significant impact on the environment both during tailing management facilities (TMF) operation and after their closure. One of the most essential impacts of operating and closed TMFs is their eolic activity, displaying in worsening air quality, aero-sanitary conditions in the neigh-boring villages and contamination of soils close to the facility by heavy metals.

Jan 1, 2005

By C. M. Liu

"The Freeport-McMoRan Sierrita Crystal Plant produces Copper (II) Sulfate Pentahydrate (CuSO4·5H2O) through a series of cooling crystallizers. In this process, high supersaturation and unwanted spontaneous nucleation promote fine crystals. Seeding through recycled crystal classification can manipulate the crystal size distribution (CSD) for larger crystals. Proper selection of the crystallizer for seeding can prevent spontaneous nucleation and promote final crystal size. This study shows when seeding temperature is closer to the crystallizer temperature, suspension densities in the crystallizers are promoted and overall CSD shifts to a larger size of crystals. INTRODUCTION Figure 1 shows an overview of the crystallization process. The in-plant feed flow, called Pregnant Mother Liquor (PML), enters the first crystallizer and is subsequently cooled through a series of four crystallizers. Specific temperatures are targeted for each crystallizer to ensure the crystallization process is operating within the metastable zone (MSZ). The discharged flow from crystallizer #5 then enters two cyclones. The overflow from the cyclones contains smaller crystals providing seed crystals for crystallizer #5. The underflow from the cyclones begins the drying process. The overflow from crystallizer #5 enters cyclone #3 for removal of fine crystals and seeding purposes. The underflow from cyclone #3 has the capability to provide seed crystals for crystallizer #1 or crystallizer #2. The overflow leaves the system as Spent Mother Liquor (SML). Undersize crystals dissolve into the PML and return back to crystallizer #1.THEORIES AND METALLURGICAL TESTS Seeding requires an understanding of the crystal size, solution temperature and amount of crystals that enter the crystallizers (1). For the seed crystal size, classified crystal seeds can prevent fine crystals returning back into the system which eventually leads to excessive agglomeration (2). Proper selection of the crystallizer can ensure seeding at an appropriate temperature. Seeding at a temperature much lower or higher than the saturation temperature promotes spontaneous nucleation. Typically, seeding between 4-5°F below the saturation temperature is acceptable (5). A general rule of thumb is to add the seed crystals at the temperature between the solubility curve and the metastable zone. An experiment conducted by Mettler-Toledo AutoChem, Inc. indicates seeding close to the solubility curve rather than the metastable zone promotes a lower supersaturation and nucleation rate but yields a higher growth rate and a greater number of larger crystals (1). The amount of seed crystals can not only change the suspension density but also narrows the width of the MSZ in the crystallizers. An experiment conducted by Jaroslav Nyvlt reports with the crystals absent, the maximum allowable undercooling is 6.3 degrees at a cooling rate, 5°C/hour. With the presence of crystals, it narrows the MSZ width to 2.2 degrees (4). Industrial crystallizers normally operate at suspension densities between 15% and 25% by mass. When suspension densities are lower than 15%, it increases the risk of primary nucleation and the probability of incrustations; on the other hand, if the suspension densities are greater than 25%, it can cause a greater attrition rate and increase the probability of deposits (6). Moreover, operating suspension densities between 15% and 25% are also sufficient to minimize supersaturation rate which promotes crystal growth over nucleation (2, 6)."

Jan 1, 2015

By Richard E. Gertsch

The recent upswing in mining coincided with increased environmental concern. These trends have significantly increased regulation, but have not always provided sound environmental protection. Throughout, mining has remained passive, reacting to initiatives from outside. The high road to environmental protection must be an active strategy. The mining industry must take the lead and develop an environmental program effective in price and protection. It must involve all levels of mining. The mining industry should be the real environmental activist. We have the most to gain by sound environmental protection and the most to lose if the environment decays.

Jan 1, 1991

By G. J. Grott

Direct Production Costs for Solar Sa 1t approximate the trucking cost for 160 Km. Operations near markets appear unusually attractive at first look. However, many desert operations have been plagued by dust storms yielding salt too high in insolubles for most uses. This paper relates the history of a successful operation in a dust storm area. Saturated brine from the solution mining of LPG storage caverns is evaporated in solar ponds yielding 99.95% sodium chloride (dry basis). Purchased energy is one-eighth that of vacuum pan operations. Production scale tests have proved it works at another desert location using a more complex brine. A new approach for refining soluble salts at ambient temperatures is demonstrated by bench scale and pilot work. Again, savings in purchased energy exceed 80%, even when temperatures are raised to reduce refining time.

Jan 1, 1988

By R. K. Singhal

The underground coal mining systems have kept pace with the developments that have occurred in other types of mining industry. A diversified group of machines with high horsepower motors, built-in microprocessor technology and with numerous options to satisfy the miners need in a varying geological environment are now available. A brief review of this existing technology and its likely status within the next 21 years is presented. Discussed also are some of the on-going advanced developments in electronic mechanization, remote control and automation together with mine wide data monitoring and management systems and facilities to process and transmit data to remote computerized stations.

Jan 1, 1989

By M. K. Han, K. N. Han, P. B. Queneau, W. J. Dawson

The development and scale up of hydrothermal synthesis processes for manufacture of high performance materials is discussed. Traditional hydrometallurgical processes are reviewed, leading into a discussion of process development concerns for manufacture of modern materials. Three case studies are presented, including a piezoelectric ceramic, barium titanate for multiyear capacitors, and high purity chromium metal. Factors for selection of reactor design are presented, as well as results of scale-up studies on the three products.

Jan 1, 1993

Ravensthorpe Nickel Operation (RNO) is a major new mine and processing plant currently being constructed by BHP Billiton in a ?green field? site near the small town of Ravensthorpe, about 150 km west of Esperance and six hours drive from Perth in Western Australia. Ensuring that the project has a positive overall impact on the surrounding region and that this extends well beyond the life of the operation will be a major challenge for RNO, state and local government, and the local community. For the last two years, the Centre for Social Responsibility in Mining (CSRM) has been assisting RNO management and the RNO Community Liaison Committee to develop a community sustainability monitoring framework for the project. This paper reports on the process that was used to develop the framework, describes the main elements and briefly discusses key learnings from the exercise.

Jan 1, 2007

By J. S. Long

A finite-difference model using a digital computer was constructed to assist in the water management of a proposed oil-shale mining operation in the Piceance Basin in Colorado. The presence of ground water is both a detriment and a benefit for development of the resource. On one hand, dewatering is required because permeable zones are present in and above the oil-shale sequence, and rich oil shale at the proposed mine is as much as 457 m (1500 ft) below the water table. On the other hand, ground water is the most feasible source of water for processing the oil shale. A ground- water model was constructed to simulate the development of an environmentally acceptable water-management system that will satisfy both the mine-dewatering requirements and the water-supply requirements for processing. The ground-water model discussed in this chapter was constructed for the Rio Blanco Oil Shale Co. (RBOSC) by International Engineering Co., Inc., a subsidiary of Morrison-Knudsen Co. The model was applied to evaluate dewatering and water control systems for several open-pit mining plans initially investigated to develop Federal Lease Tract C-a. A collateral application of the model analyses was to project effects of the proposed dewatering operation on the regional ground-water regime in connection with a permit acquisition program by RBOSC. Subsequently, RBOSC has completely changed its mine development plan and has adopted modeling and related techniques more suitable for study of that plan and dewatering operation. The authors of this chapter are solely responsible for the contents and conclusions.

Jan 1, 1979

By Michael Bayerl

The HILTI OneStep rockbolt was implemented for roadway development in German deep coal mines in 2004. The development by HILTI Company is based on a technical joint venture with RAG Deutsche Steinkohle AG. The technical development of a One-Step bolting system was required for weak strata conditions at the roadway development face. Standard resin bolting has reached the limit of performance when boreholes are squeezed and cannot be filled with capsules. In some cases the heading face is brittle and requires additional support for installation of the bolts and a person working immediately next to the borehole. The Hilti One-Step system allows automated and safe processing at the heading front and provides the key technique to avoid these problems.

Jan 1, 2009

By C. E. Capes

INTRODUCTION In the coal industry, ever greater amounts of fine coal must be processed due to the need to crush to finer sizes for impurity liberation in low cost physical cleaning processes. Fine coal processing is a major problem for the industry, both through the cost of disposal of reject fines and through the mining cost of lost coal values. Of the available disposal methods, impoundment has always been the most popular. In many cases, when the coal fines were of sufficient quality, froth flotation and expensive filtration methods were used to recover the coal in these waste streams. The coal fines are not always of a marketable quality, however, and flotation, due to poor yields and difficult dewatering, has always been an expensive and not necessarily profitable process. The oil agglomeration method is increasingly important as a technology for the treatment of fine coal-in-water suspensions. These fines can be preferentially wetted and agglomerated by many different oils mixed with the suspensions. Ash-forming impurities remain in suspension and are rejected when the agglomerates are recovered, for example, by screening. Agglomeration-based methods provide perhaps the only practical means for upgrading extremely fine coal to useful products on a large scale. As with froth flotation, oil agglomeration relies on differences in the surface properties of coal and impurities to effect separation. Whereas flotation be- comes less effective with particles finer than 200 mesh (0.075 mm) or coarser than 50 mesh (0.3 mm), there appears to be no lower limit on particle size for oil agglomeration while particles % in. (3.175 mm) diameter or larger can also be treated, if desirable. In addition to this ability to clean a broader size range of coal particles, oil agglomeration can produce a dense, coarse granular product of acceptable strength and low water content without the need for vacuum or thermal drying. The preferential wetting of solid surfaces by immiscible liquids has been utilized, if not fully understood, for a long time. Indeed Gaudin,229 in tracing the ancestry of froth flotation, refers to a 15th century oil-pulp kneading procedure in which water-wetted particles were freed under water from an oiled mass. An understanding of the physical chemistry involved in such

Jan 1, 1991

By R. Schuerch, G. Anagnostou, R. Poggiati

"The paper presents dimensionless design diagrams for estimating the stand-up time of a tunnel face in saturated ground of medium-low permeability. The diagrams cover a wide range of ground parameters and apply to shallow tunnels (overburden less than two diameters). As the time-dependency of the face stability in water-bearing ground is associated with the consolidation process in the soil ahead of the tunnel face, the stand-up time is determined by means of hydraulic-mechanical coupled spatial stress analyses. The results presented are important for tunnel engineering practice, e.g. when estimating the feasibility of atmospheric interventions in the working chamber of a closed shield. INTRODUCTION The response of water-bearing medium-low permeability ground to tunnel excavation is time dependent. The time-dependency is due to a transient seepage flow process that is triggered by the excavation and develops slowly over the course of time. Experience shows that the short-term behavior the ground is more favorable than the long-term one: the deformations increase with time; the tunnel face may be stable initially and fail only after some time. The time over which the tunnel face remains stable is called the stand-up time. This paper investigates the time dependency of the tunnel face stability assuming that all time effects are due to consolidation rather than creep. This assumption is reasonable for shallow tunnels crossing water-bearing soils. In the problem under analysis, the unsupported tunnel face remains stable under the undrained conditions prevailing after excavation, but collapses before reaching the drained conditions prevailing at a steady state. The assessment of the stand-up time is important from an economical point of view for both mechanized and conventional tunneling through weak water-bearing ground, as a long stand-up time removes the need for face support or ground improvement works during standstills, thus saving time and money, while short stand-up times require hyperbaric interventions or the implementation of costly and time-consuming auxiliary measures."

Jan 1, 2016

By R. Schlüter

"The global mining industry is facing increasing challenges in terms of geological, technological and social aspects. Potential exploi-tation of deposits shows a tendency to increasing depth with complex ores and decreasing grades. A promising approach to deal with these constrains is by applying alternative extraction methods like (bio-)hydrometallurgy as in-situ leaching (ISL) technology. The Bergakademie Freiberg University of Mining and Technology established the “Biohydrometallurgical Center for strategic Elements” (BHMZ) to foster the interdisciplinary research along the entire biohy-drometallurgical process chain to extract indium from sulfide ores. The involved Department of Underground Mining Methods deals with the design and implementation of a pilot-scale underground testing facility for microbial in-situ stope leaching in its “Research and Educational Mine”. This paper discusses the potential of in-situ bioleaching under technological aspects. In addition, different conditioning approaches based on hydraulic and explosive methods for enhanced permeability in the formation are introduced and the gathered data will be presened. INTRODUCTION A reliable, substantial and sustainable supply of raw materials is of crucial importance for any industrialized country. This dependency applies to “strategic elements” including rare earth elements (REEs), platinum group metals (PGMs) as well as a variety of other metals like indium and germanium which are needed for high-tech industry and products such as electric and electronic devices, fibre optics and laser technology (Barakos et al., 2016; European Commission, 2010). Due to the economic growth of the BRIC-countries (Brazil, Russia, India, China), the resource policy of China as well as the volatile world mar-ket prices of different metals the availability of these critical raw materi-als and therefore the dependency of the high-tech producing countries has become increasingly important (Barakos et al, 2016). Adequate supply is often affected by the increasing depth of de-posits, lower metal concentrations and more complex ore mineralogy. In addition, mining activities are increasingly restricted by their envi-ronmental and social impact and footprints. As a consequence, con-ventional mining and processing methods are limited by high energy consumption and technical constraints."

Jan 1, 2018

By J. G. Groppo, B. K. Parekh

Column flotation testing was conducted on the flotation feed slurry obtained from a preparation plant located in the Southern Illinois coal basin. The column flotation tests were conducted using three different bubble generating devices: a static sparger, a gas saver and a foam jet. Each of these devices was tested with three different types of frother and various column operating variables to provide maximum combustible recovery, minimum product ash and maximum pyrite rejection. The results show that column flotation provided improved flotation performance, in terms of combustible recovery as well as ash and pyrite rejection, for each of the bubble generating devices. However, the effectiveness of each bubble generating device was dependent on the type of frother used. Alcohol frothers were most effective for use with the static sparger, somewhat less effective for the foam jet and ineffective for the gas saver. Glycol frothers were effective for all three bubble generating systems, providing high combustible recovery (>90%); low clean-coal ash (4-6% ash) and high pyrite rejection (70-80%).

Jan 1, 1994

By D. Leppert

Large deposits of natural zeolites may provide cost-effective alternatives for treatment of soil and water contaminated ) with heavy metals and radionuclides. Research on the Bikini atoll demonstrated that addition of clinoptilolite to the soil significantly reduces cesium uptake by plants. Re- search on the potential use of zeolites in soils at Bunker Hill, ID indicated only minor benefits at very high contamination levels vs. US Bureau of Mines (USBM) work on the use of zeolites for treatment of mine waste waters emphasized problems with natural waters that previous studies have not addressed. High levels of competing calcium in natural waters significantly decrease the effectiveness of zeolites for heavy metal sorption and may limit the usefulness in these applications.

Jan 1, 1991

By Paul Culvenor, Brad Gyngell

Ensuring effective management of contractual processes is essential for maintaining profitability and operational efficiency in mining. However, due to limited capacity and resources, sites often struggle to manage these processes effectively, leading to oversights and financial losses. Recent advancements in Artificial Intelligence (AI) offer promising solutions to these challenges. Large Language Models (LLMs), like those powering ChatGPT, now enable machines to understand unstructured data like contracts. These can therefore be applied to address these challenges by taking some of the heavy lifting off of humans. In this paper, we analyze a real-world case study of the application of LLM tools for preventing a $400k contractual issue on an underground gold mine in Western Australia. We provide a gap analysis of the failure modes in existing processes that led to the issue. We then describe the application of LLM tools to flag it early and facilitate a collaborative solution between the operator and the supplier. This includes a comparative analysis of base case vs LLM case to evaluate the impact on project cost and time. Finally, we discuss how the integration of AI can foster improved relationships between clients and contractors across a broad range of potential contractual applications, allowing the time required for collaborative and proactive problem solving.

Feb 1, 2025