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By K. A. Prisbrey

Mineral carbonation is the reaction of carbon dioxide with mineral silicates to form solid, carbonate compounds. The carbonate ion holds carbon in a low energy state – lower than in carbon dioxide. Thus the reaction of carbon dioxide to produce mineral carbonates captures the carbon in a stable, solid form. The University of Utah is investigating the carbonation of silicate minerals by mechanochemical processing, which has the potential of being much less expensive than other methods. Tests to date have shown that a marked change takes place in the lizardite variety of serpentine after 15 to 20 minutes of intense grinding in the presence of gaseous CO2. Further testing is in progress.

Jan 1, 2004

By Dr. -Ing. Karlheinz Timtner

This paper deals with the complicated and often misunderstood relationship between torsional windup, load sharing and peak torques in conveyor backstops. The principals apply in low speed, intermediate speed or high speed applications. Once the controlling factors are understood, a reasonable approach to selection procedures can be achieved.

Jan 1, 1996

By R. L. Schmidt, Williamson. T. N.

INTRODUCTION This paper describes one of several research projects funded by the Advanced Research Projects Agency to extend the technology of rapid underground excavation. This study and field research effort are to investigate alternative means to determine rock and geological conditions in advance of a tunnel boring machine (TBM). Approximately 1 year of a planned 3-year program has resulted in the definition of three candidate drill systems. Hardware has been assembled to field test these candidates and testing has begun. The 3-year objective is to develop a single optimum prototype drill and test it in an active TBM operation. ACKNOWLEDGMENT This research was supported by the Advanced Research Projects Agency (ARPA) of the Department of Defense and was monitored by the Bureau of Mines under Contract No. H0210037. The authors and sponsoring agencies are indebted to the quarry operators in California, Virginia, and West Virginia who offered assistance including access to their properties.

Jan 1, 1997

By Jouko Suominen

The basic development of various mining equipment has been strongly influenced by two objectives; improving economic results and safety aspects. Both of these factors contribute to increased requirements of mechanization and automation in different parts of mining processes. When we are limiting the discussion the crushing circuits, automation has two dimensions, one being the component automation, or intelligence, the other being automation of complete processes. Both of these subjects are closely tied up, the former being a condition for the latter. The key technologies of crushing automation are transducers, programmable logics and computer software. Also equipment technology continually faces new challenges, which result even in totally new product families. One example of this kind of development area the track-mounted, integrated crushing systems, where design criteria have been simple control, unmanned operation, and flexibility in changing requirements. This crushing system, or philosophy, offers excellent possibilities for new concepts in various underground and open pit applications, connected with automatic process control. Following presentation is a summary of aspects, of haw a crusher manufac¬turer sees the development of automa¬tion as an integral part of equipment technology and development.

Jan 1, 1989

By P. Venkatasubramanian

The selection of a mining method for a mineral deposit is a complex decision problem. Human judgment, based on experience with mineral deposits and geologic conditions, remains the single most important input of the decision-making technique. If the use of artificial intelligence, in particular the developments in expert systems, is taken to its logical conclusion, the experience of the domain experts could be incorporated into a decision-support expert system. A knowledge-based decision support system for mining method selection for ore deposits has been designed whereby the domain knowledge is represented as production rules and organized in a semantic tree representation. This model is written in the PROLOG language. While the verification difficulties of expert systems models are recognized, an example of the model's decision on the mining method for a given ore body is presented and shown to be consistent with the decision made by human experts. In addition, plans, for further verification of the model are delineated.

Jan 1, 1992

By R. E. Weeks, D. J. Millenacker

Utilization of true in situ technologies for mining copper in Arizona will involve a complex environmental permitting process. This process is a key factor in determining the feasibility, costs, and implementing time- frames required for development of this innovative mining method. The regulatory structure in Arizona is presently changing due to enactment of the Environmental Quality Act (EQA) of 1986 and development of new aquifer protection rules and regulations. The US Bureau of Mines has reviewed the comprehensive hydrogeologic characterization, ground water monitoring, mechanical integrity testing, well construction, contingency planning, and other regulatory elements that will serve as mechanisms to assure protection of ground water resources. The purpose of this paper is to inform the domestic copper industry of the significance of the new Arizona regulatory structure and its implications for prospective in situ operators.

Jan 1, 1987

By R. Gerling

A computer program has been developed for finding a near-optimum schedule of the mining sequence for flat lying, tabular orebodies. The deposit is divided in blocks with equal areas and definite grades, thicknesses and ore contents. Mining is done by room and pillar method and trackless haulage to surface. Access from surface is by adits or ramps with additional vent raises. In total eight different general concepts for access and development can be realized. The optimum mining sequence is found by a heuristic method. Criterion is the maximization of the net present value over the lifetime of the mine. Specific stoping costs per t of ore are taken for con¬stant, whereas development and haulage costs for individual blocks and also sequences will be different. Correct ventilation and a technically sensible sequence are guaranteed. Beginning with a single block, neighbouring blocks are tested and an optimum stoping sequence is generated. The net present value of the total mining operation for the planning period is calculated, taking into account ore, which is mined during development. The program can also be used to investigate given mining sequences.

Jan 1, 1986

By Edward C. Dowling

The advance of science and technology influences the modern economy in countless ways. Older industries must adapt to changes in the marketplace, while new industries are born by applying new technology to meet consumer needs. In light of declining head grades and increased unit costs in the US minerals industry, new technological developments in the production environment are paramount to maintaining a competitive footing in the international marketplace. Micro-engineering research provides the transition between the knowledge base and the application of new technology on the production level. Economic considerations The primary goal of technical development in the production environment is to reduce unit operating costs. Simply stated, this is accomplished by improving operating efficiencies and productivities on the production level. The goal of micro-engineering research in the production environment is to evaluate promising technologies and develop the criteria necessary to apply them in operations. As such, this process is the first step toward innovation and discovery. Generally, the micro-engineering research is followed by macro-engineering development. In the production environment, there are generally more development projects than can be accomplished in a timely manner. Usually, this is the result of financial and human resource limitations. Consequently, it is necessary to prioritize the work such that the most beneficial projects are accomplished first. By performing a discounted cash flow analysis and using benefit-cost ratios (for non-mutually exclusive alter¬natives) or net present value criteria (for mutually exclusive alternatives), the projects can be rated from best to worst. In this way, the financial and human resources can be best allocated to first complete those projects giving the highest returns before moving on to other activities. Moreover, this information is a prerequisite for management to justify additional financial or human resources.

Jan 1, 1992

INTRODUCTION Automatic controls are devices that assist operators by performing routine tasks faster and better than they could alone. Great strides have keen taken in the development of new processes and bigger machines to improve productivity, but these developments created the need for increased protection of machinery and labor. The new production-line techniques, or continuous processes developed, resulted in routine and, frequently, demoralizing jobs. The human race is not constituted mentally to perform routine operations. Devices were needed also to gather information automatically and perform routine functions. High-capacity plants incorporating large equipment

Jan 1, 1985

By D. S. Holmes

Biological processes for metal solubilization and ore beneficiation are in widespread use today. There are also some promising new applications of biotechnology in the areas of metal concentration and toxic metal cleanup. Recent progress in genetic engineering promises both to revolutionize the existing biological process and to expedite the adoption of the new biological applications. But before it can do so effectively, progress must be made in many areas of fundamental research and in biochemical engineering. These issues are addressed with special reference to the biotechnology of semi-enclosed containers (bioreactors), dumps, heaps, in situ and under- ground leaching, and with respect to the biotechnology of metal concentration. Finally, certain biological considerations for bacterial strain improvement are discussed.

Jan 1, 1987

By Albert E. Ketler

The techniques for fire monitoring of conveyor belts in underground coal mines have been revolutionized by the advent of sensitive carbon monoxide sensors and computer monitoring systems. These new systems are rapidly replacing the previous thermal (fixed-point temperature) sensors that have been shown to be considerably less sensitive for early fire warning. CO is generally an excellent indicator of spontaneous combustion. However, the most recent non-flammable conveyor belt materials have been shown to "burn" with dense smoke, but without sufficiently high temperatures to produce much carbon monoxide. To cover this fire detection void, a smoke detector was developed to augment CO sensing for these new conveyor materials. However, computer monitoring provides the flexibility for handling this and other additional instrumentation as fire monitoring techniques evolve. CO, smoke and temperature sensing may eventually be advocated for complete fire monitoring.

Jan 1, 1987

By John B. Jones

New concepts in shaft kiln processing are included in the design of two large diameter shaft kiln plants now under construction. One kiln will be used to produce cement clinker at the Boettcher plant of the Ideal Cement Company at Fort Collins, Colorado. The other kiln is for the semi-commercial oil shale plant for Petrobras, the Brazil National Oil Company at Sao Mateus do Sul, Parana, Brazil. Investigations on application of the new concepts are proceeding in a portable pilot kiln. The shaft kiln has long been recognized as a method of gas-solids contacting having the following principle advantages: l. High thermal efficiency 2. Ability to handle a variety of feed materials with a wide range of particle sizes 3. Minimum investment and operating cost

Jan 1, 1963

By L. Spiers

Motorized Conveyor Pulleys contain all the traditional conveyor belt drive components inside the pulley. Light duty airport check in, grocery stores and food processing conveyors; requiring compactness, elimination of guarding and component containment have been using them for years. Portable Aggregate Processing Equipment require these features but with higher belt pulls and severe duty beyond the capacity of traditional components in a limited space. New materials, design technologies and automation; converging with safety issues, higher energy and operating costs; have created a pressing need. The challenge is to integrate new technologies and traditional components into a reliable, compact, conveyor belt drive system.

Jan 1, 2003

By John Durkin

A system based on seismic techniques has been developed to detect and locate men trapped underground following a mine disaster. Both theoretical and field studies have been used to generate models to predict the performance of the system. For a strong source, it is almost certain that the miner's signal will be detected if the geophone array can be positioned over a likely area of entrapment. After signal processing, it is highly likely that the location of the miner can be determined within an accuracy of 100 ft (30.5 m). The system is presently operational in a state of readiness in the event of a mine disaster.

Jan 1, 1980

By C. W. Lockhart

Strength evaluation programs, based on sub- jecting a number of 5-718 inch (0.15 m) diameter core samples from highly fractured or poorly consolidated rock, to triaxial compression tests, have been successfully completed. An innovative approach was required since con- ventional methods with similar materials had not produced reliable results. Drilling methods were modified, and specially designed transparent core barrels were used. Sample preparation was successfully accomplished by using speciallydesignedtools and unorthodox hand- ling methods. Initial tests were carried out on weathered oxides from an open pit copper mine. The technique was later used successfully where the test material was weak, friable coal. The procedures used offer a practical method of testing weak materials where conventional methods would not be successful.

Jan 1, 1980

By Timothy Batchler, Khaled Mohamed

Standing supports have been used in coal mines for decades to enhance roof support capability. Occasionally, standing supports are used to resist the lateral movement of spalled ribs. Researchers from the National Institute for Occupational Safety and Health (NIOSH) are conducting a testing program for standing supports to investigate the effect of lateral loading on their vertical loading capacities and the factors affecting their lateral loading capacities. The Mine Roof Simulator (MRS) was used to determine the response of steel props to vertical and horizontal loadings. Finite element models (FEMs) were developed and verified using the tested steel props. Prop models were used to study the effect of a range of roof and floor materials — gray shale, shale and claystone — on the critical buckling loads of the steel props.

Dec 1, 2022

By Hiroyuki Kawata, Toshiyuki Ueno, Mikio Yamazaki

INTRODUCTION For the construction of several kinds of structures which pass through under railways, we have recently developed an effective and new tunnel construction method, aiming at more secure train operation during the construction as well as the rationalization in the construction works for such structures. Most important in carrying out the construction works for the structures under railways is how to maintain the safe operation of trains. For such construction works, temporary supporting structures and supplemental works have been often applied, for which high cost and long period for the construction have been required. While, this new tunnel construction method has the feature that it is capable of constructing definitive structures for various purposes, which, at the same time, acts as the temporary supporting members for protection of railways. Therefore, this method is now drawing much attention in that higher safety of train operation, low construction cost, and shorter construction period are accomplished, minimizing the period required for slackening the train speed during the construction works.

Jan 1, 1979

By K. V. Raj, R. Jacksha

Conveyor systems persist in being a source of injuries and fatalities in the mining industry. To reduce these incidents, better methods are needed to enhance the monitoring of probable hazards and improve situational awareness during the normal operation and maintenance of conveyor systems. To address these issues, researchers from the U.S. National Institute for Occupational Safety and Health (NIOSH) continue to investigate emerging technologies that show the potential to improve miner safety around conveyors. This paper presents a feasibility assessment by NIOSH researchers of a fully integrated, commercially available wireless Internet of Things (IoT) system to improve situational awareness around conveyor systems.

By M. H. Kotze, M. J. Virnig, G. Steinbach

Earlier work at Mintek on the development of gold-selective resins culminated in a plant-manufactured batch of the first generation of Minix resin. A subsequent pilot-plant campaign at a South African gold mine identified some problems with that resin. These included lower capacity and selectivity for gold compared with the laboratory prototype, and a slow but progressive loss in capacity as the resin was eluted and reloaded cyclically. These problems were overcome by chemical modification of the resin structure. Examples of these improvements are presented. The commercialization of a new resin for a new metallurgical application presents problems, which are exacerbated by the initial lack of demand for the resin because the process is unfamiliar to the mining industry. Progress in the commercial development of Minix is discussed in this context.

Jan 1, 1993

By C. H. Smith

The present interest in beryllium seems to be the result of recent developments in the uses for the metal discovery of significant deposits of disseminated beryllium ores, and the development of chemical and physical processing techniques, for recovering the beryllium values contained in these ores. At the present time most of the new and potential uses for beryllium are in the research stage of development and are not consuming large quantities of the metal. However, they do point to an expanding market. Interesting new discoveries or extensions of previously known deposits have been reported during the past year from the Boomer Mine in Colorado, the Mesquite area of Nevada,, the Chemalloy pegmatites in Canada, the Brazilian and African pegmatite districts and from other areas, However, this paper will discuss only four of the beryllium deposits, which appear to be of special significance due to their; large reserves of ore and promise economic development. The new chemical and physical processing techniques are not discussed in detail, but it should be stressed that the development of an economical process to handle the pegmatitic and low-grade non-pegmatitic beryllium ores is of great importance to the development of the beryllium industry. Scientists in both government and industry are co-operating in this effort and it is expected that commercial processes will be developed in the near future.

Jan 1, 1962