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By D. Zaharaki

The optimisation of geopolymer synthesis was studied bymixing low Ca electric arc ferronickel slag with kaolinite, sodium silicate solution, sodium hydroxide pellets and water. The pulp was heated at low temperatures and left for curing at room temperature. Through statistical analysis it was shown that the factors with the most statistically significant effects on the compressive strength of the produced geopolymers are slag particle size and aging period. XRD and FTIR studies provide useful information regarding the progress of geopolymerisation mechanisms. Finally, studies regarding the durability and structural integrity of the produced geopolymers were also carried out.

Jan 1, 2006

By D. Nilsson

This paper demonstrates the importance of including a discount rate in the determination of the optimum final depth of an open pit. Without a proper discount rate, a pit will probably end up too deep. Another consideration is future underground mining. If underground mining is profitable, the pit may need to be shallower. Of all of the investments needed, only mining equipment and the underground mine should be included, and amortization and depreciation should not he included in the study.

Jan 1, 1998

By H. S. Rathor

In a major hydropower project in the Himalayas, during excavation of tunnel, hydrothermal gradient line appeared and caused extremely unfavorable conditions with rock and water temperature varying between 55°–66°C and nearly 100% humidity. Major changes in method of excavation, schedule of works, deployment of additional equipments and acclimatization of personnel were made to complete this unfavorable stretch of world’s longest Head Race Tunnel. The case study covers the various aspects of tunneling in geothermal rocks, inhuman working conditions, loss of production, cost overrun, contractual claims and strategy to manage such unfavorable working conditions.

Jan 1, 2003

By George Wilson

As the economic and environmental attractiveness of conveying coal and ore slurries by pipeline increases, greater attention has been given to designing and selecting components for these pipeline systems. Pumps are one critical element in pipelining. Pumping slurries is a particularly arduous task, calling for special design and construction. The first article in this two-part series describes some factors to consider when selecting pumps to resist abrasive wear.

Jan 9, 1981

By Tim Wolf

The paper "Weld Notch Affects on Pulley and Belt Conveyor Reliability" has done an excellent job of describing theoretical fatigue and fracture mechanics methods used in modern weld design. From this foundation, we intend to further detail areas previously discussed and present new research in the application of these principles to pulley weldment life prediction. Affects of changes in alternating stress range, mean stress, and residual stress have been investigated using controlled laboratory fatigue tests on a pulley weldment. Comparisons between these results, weld codes, and theoretical fatigue predictions will be made and discussed.

Jan 1, 1998

By Gary PE Beerkircher

A brief history of banana screen development and evolution will be presented along with the operational advantages of the large banana screens available in the industry today. Applications of the large banana screens will be presented as well as the economic advantages that the use of large banana screens can offer to the Mining lndustry today. Banana screen installations in metal, non- metal and coal mining applications will be presented.

Jan 1, 1997

By Athorn Mary-Lee, Randall A. Snowdon

During the development of the Selby Coalfield, UK, a Robbins full-face tunnel boring machine (TBM) and a Thyssen Titan roadheader were used to drive a pair of parallel spine roadways. This paper presents a summary of the comparative operational and cutting performance of both the Titan road- header and the Robbins TBM. Statistical techniques were employed to identify relations between machine performance and geotechnical parameters.

Jan 1, 1986

By Ahmed A. El-Saie

To reduce the problem of overbreak and its associated added costs, a new technique is proposed to make a slot around the tunnel profile in hard rock. The Finite Element Method was used to investigate the effect of the slot on the stress field and deflection of the tunnel core. Beam theory was also applied to calculate the stresses and deflections of a slotted tunnel for several different slot depths.

Jan 1, 1981

By Michael Elliot-Jones

The fundamental competitive structure in world coal markets will be modified by the entry of such new participants as Colombia and the newer mines in South Africa. The US will, in most markets remain the swing producer, although a number of low cost US mines will continue to compete in world markets. Exchange rate swings will persist as a major hazard for coal exporters.

Jan 1, 1986

By I. C. Watson, J. W. Klokow, A. F. Knoetze, R. G. B. Pickering

In the late 1970s and early 1980s there were a number of attempts to use Tunnel Boring Machines in deep level gold mines. These attempts must be regarded as unsuccessful. Since then there have been comprehensive developments in tunnel boring equipment and tunnel support technology. This paper defines the problems experienced in those early trials, reviews the technology development, and concludes that tunnel boring in deep level goldmines can be justified in today’s environment.

Jan 1, 1999

By T. W. Conrad, B. Kerr

During the last decade grassroots minerals education programs have blossomed throughout the United States and in other countries. At the same time an environmental education movement has been gaining momentum. While this offers a unique opportunity to share the mining industry’s story, it also has some potential pitfalls. In this paper the authors will discuss some of the benefits of participating in environmental education and provide some practical tips for success, based on New Mexico experiences. It will conclude with a presentation on a successful environmental education program at Heights Middle School in Farmington New Mexico.

Jan 1, 2001

By Lynn B. Hales, Randy Ynchausti

Expert systems are now being used effectively to streamline and improve the performance of supervisory computer control strategies. Their advantages have led to use in both batch and continuous applications. Expert systems in the context of real-time process control, will be defined and examples of their successful implementation in autogenous, semi-autogenous and ball mill grinding circuits will be discussed.

Jan 1, 1990

By Romeo Jurani, Ralph Dresel, Fred Kissell, Charles Parker

This report describes actions taken to control silica dust at the Yucca Mountain Exploratory Studies Facility (ESF), a tunnel located in Southern Nevada that is part of a scientific program to determine site suitability for a potential nuclear waste repository. The rock is a volcanic tuff containing significant percentages of both quartz and cristobalite. Water use for dust control was limited because of scientific test requirements. A major dust reduction was achieved with an intermediate air cleaning station located on a rear deck of the TBM trailing gear.

Jan 1, 1999

By C. Bazin, B. Girard

The application of time series analysis techniques to plant data provides a method for examining and modeling the behavior of operators during the operation of furnaces for the reduction of ilmenite concentrate. The obtained model is used to assess the consistency of actions carried out by the operators and to review and improve the training procedures.

Jan 1, 1996

By D. R. Taylor, R. G. Goss

The use of clay granules as carriers for pesticides dates from the early 1940's and by the present day represents a business conservatively estimated at between 200 - 300 thousand tons / year in the U.S. alone. Aside from economic and specific target pest efficacy advantages, the use of clay granules as pesticide carriers also delivers a number of environmental benefits which will be reviewed. Topics to be discussed will include: 1) drift control (versus liquid sprays), 2) mobility (in the environment), 3) worker safety, and 4) transportation (spill) safety.

Jan 1, 1999

By L. B. Hales

Color video or digital cameras have been installed over flotation cells to monitor color, bubble size, froth movement, and other characteristics. These systems are designed so that the camera provides flotation performance information just as any other sensor might. Factorial tests have been run to monitor and measure the variation in froth characteristics as a function of flotation control settings. Ultimately, it is envisioned that froth image sensors can be used to monitor and control the flotation performance as effectively and for less cost than current analytical systems.

Jan 1, 1999

By Blagoj Golomeov, Boris Krstev

Nowadays, in the papers of authors in the area of flotation concentration, we can find several equations that describe the kinetics of flotation process as follows: Agar's equation, Klimpel's equation, Beloglazov's equation and Group of authors' equation (equation with two kinetic constants). This paper makes an attempt to determine the most appropriate equation for mathematical interpretation of kinetics of the SASA mine rougher Pb - Zn flotation.

Jan 1, 2002

By S. D. Bearden

The world's barite reserve base is adequate for at least 100 years at the current consumption rate. China, India and the United States are expected to remain the leading producing countries, and the United States will continue to be the largest consumer. None of the known substitutes for barium sulfate are expected to impact existing applications. World production in 1995 was 4.41 Mt (4.86 million st), which is about 50% of capacity. Consumption is directly proportional to hydrocarbon well installation activity. Imports are expected to continue to supply more than half of the US requirements.

Jan 1, 1998

By D. John Curtis, Gordon S. Crighton, John C. Hester

The six main drives needed to build 55 miles of 4.8 and 7.7 metre i.d. tunnels in 33 months called for careful co-ordination of the design of tunnel boring machines and linings. The implications of these requirements are discussed, with particular reference to the selection of tunnel liners. The solutions adopted are detailed and details are given of the specifications and procedures adopted. The design methods employed for liners are outlined. The construction methods are described and current performance figures given.

Jan 1, 1991

By A. C. Lyons

The presentation describes the history, preliminary report, site investigation, including examination of old records, design of tunnel including choice of levels, alternative linings and working sites, the preliminary contract involving shaft sinking on the site of the Tower Block; design modifications, the main contract, including shaft sinking, ground treatment, compressed air installation, machine tunnelling, tunnelling enlargements for chambers, waterproofing and equipment.

Jan 1, 1981