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By Stuart M. Jones, Eugene E. Hively

The Tower Mill is a vertical "stirred" ball/pebble mill recently Introduced In the Western Hemisphere This device offers a significant power savings on wet fine grinding applications when compared to conventional tumbling mills This paper describes the laboratory application of this mill In wet grinding hydrated alumina to products of 50 percent passing 2 to 6 microns

Jan 1, 1983

By B. Suresh, Kalyan K. Das, Pradip

A series of salicylaldoxime derivatives with alkyl group substitution in the main chain and the side chain were synthesized and evaluated for the flotation of malachite, cerussite and smithsonite. The effect of chain length and the position of the substituent group on the selectivity of separation amongst oxidized copper, lead and zinc minerals are discussed in this paper.

Jan 1, 1995

By M. Misra, I. Anazia

The effects of the enzyme, peroxidase, on the sedimentation and consolidation characteristics of Florida phosphate slimes were investigated. Results indicate that pretreatment with the enzyme was beneficial for slime dewatering and consolidation. Biological activity, resulting from slime pretreatment with the enzyme, induced higher mechanical binding between slime particles.

Jan 1, 1990

By Tracy Braun, Dan Lampshire

Over the past decade, heap leaching at Cortez has evolved from a rather small operation producing around 30,000 ounces per year of gold to an operation scheduled to produce over 400,000 ounces in 2004. Evolution and expansions in the heap leach operations are discussed including plant design criteria and some of the design features in the various facilities. Operating parameters and production forecasting are also discussed.

Jan 1, 2005

By Harry C. Oussoren, James C. Miles

A new seven kilometer long subway line is being constructed through dense glacial soils under a major thoroughfare in Toronto. Eductor, deep well and vacuum wellpoint systems are being used to lower the water levels by as much as 16 metres for the construction of the twin tunnels and associated structures. The design and performance of the dewatering systems will be described. Unanticipated difficulties and their solution will be presented.

Jan 1, 1999

By J. G. Nalven, J. A. Sturgess

On July 1, 1999, most domestic metal mines will have to report releases of toxic chemicals into the environment for the first time as required by SARA Title 313. Some of these reportable releases will appear huge in relation to reports by other industries. The reasons for the potentially large reportable releases, special considerations for mining operations, and strategies for dealing with the reports are described. Data composited from experience with several mining companies is presented in the context of a typical goldmine.

Jan 1, 1999

By J. M. Gambogi

Demand for titanium minerals and pigments was nearly unchanged in 1996 compared with 1995. However, through mine expansions and process optimization by the TiO, pigment industry, the available supply of titanium minerals and pigments increased moderately. At the end of 1996, exploration, development and expansion programs were ongoing in the mining sector. But expansion projects in the pigment sector were delayed pending increased demand.

Jan 1, 1997

By Jim W. Rosteck, Anthony Del Vescovo

In December of 1992, the City of New York, Department of Environmental Protection, solicited bids for Contract 543B. The low bidder was a joint venture of Schiavone Construction Co., Inc. and the J. F. Shea Co., Inc. When completed, the project provides a 4.88 meter diameter water tunnel 8,840 meters long. This paper presents a case history of the equipment and construction methods utilized for this, the first portion of the New York City Water Tunnel constructed by use of a tunnel boring machine.

Jan 1, 1997

By R. C. Freas

Limestone is a basic raw material in the production of cement, lime, a wide variety of industrial products, and a significant percentage of the crushed stone produced in the United States annually. It is used in fluxes, glass making, mineral fillers, environmental applications such as flue gas desulphurization and water treatment, soil conditioners, animal feeds, and as a construction aggregate. This presentation provides an overview of limestone distribution in the United States, it’s production, the variety of products produced, and a brief review of the primary uses for limestone.

Jan 1, 2006

By Bekta? Uz

The study area is located between Orhangazi and Sapanca geographically known as Armutlu Peninsula (Figure 1). It is steep broken and mountainous with an area of 4000 km2. [ ] Economic marbles are investigated in regionally such as Orhangazi, Elmali, Menek?eyayla, Sapanca, Pamukova and they are seperated approximately 800 km2 (Figure 2). These marbles are massive, thick and dispersed as small sized outcrops in Armutlu Peninsula.

Jan 1, 2005

By J. Iannicelli

Kaolin, normally an inert filler when compounded with polymers, is converted into a strongly reinforcing pigment by prereaction with certain functional silanes. Modification of kaolin with amino and mercaptosilanes allows it to form crosslinks and confers significant improvements in modulus, abrasion resistance, compression set and other physical properties of a broad range of polymers.

Jan 1, 1992

By Robert T. Tape, Thomas G. Harper

Valley-fill heap leaches built in steep terrain over low-friction angle liner system may be unstable even though analyses indicate stable ore slopes. This paper demonstrates the potential for massive heap failure using stability analyses which consider both heap slope and heap mass failure considerations. The computations presented also reveal the sensitivity of mass heap stability to liner friction angles.

Jan 1, 1987

By Shahid A. Pirzada, Milton Manrique, Patrick R. Taylor

Microsilica or silica fume is a waste material generated from silicon or silicon-containing alloys producing electric furnaces. One of its usage is as an additive in the concrete production. This investigation describes a process to use microsilica as a feed material to produce fine silicon carbide. A thermal plasma reactor is used to convert this waste material into a value added ceramic. Details of the theoretical considerations, experimental work, and characterization are presented in this work

Jan 1, 1995

By H. Nematollahi

Numerous magnesite deposits are found in the south part of Khorasan state, east of Iran. During the past few years, production of high-grade magnesite ore was possible only by using selective mining method. The decreases of high-grade ore imply upgrading of the low-grade ore. To do so, the objective for the first phase is to obtain a material which contains less than 2.5% SiO2. The present study was carried out based on three different samples. The results obtained in laboratory indicate that the direct flotation of magnesite by fatty acids led to acceptable result.

Jan 1, 2003

By S. Luning

In the nineties the gold sector in Burkina became subject to internationally prescribed liberalization policies. The national state is at present only one of many players. Who are these players, and how are they involved with one another in organizing goldmining activities and prospects in Burkina? One mining site serves as a case to study the scope of players and the types of authorities they build upon in governing gold sites. What conclusions can be drawn in regard to the present position of the Burkinabe state within this field of governing authorities?

Jan 1, 2007

By Roy H. Patten

When driving a shallow soft ground bore, the appearance of surface craters along the tunnel alinement indicates trouble, particularly when a major highway is intersected. During the excavation of a 3.7 m diam tunnel in Seattle, Washington a chemical grouting program was implemented to stabilize soil conditions sufficiently to allow advancement of the mole without loss of ground. Unanticipated mixed face conditions consisting of saturated running sand and some boulder pockets bedded on top of dense glacial till created excavation difficulties. A discussion of problems and corrective measures is presented.

Jan 1, 1987

By K. F. Hollberg, D. Graehl, L. Despain

OCI Wyoming's recent expansion of its surface Soda Ash production facilities outstripped the mine's ability to supply Trona ore necessitating infrastructure changes to the mine. A computer simulation of the mine's production systems along with the surface facilities was created to determine the most economic investment alternatives to increase mine production. This paper describes the development of the simulation model; the results obtained, and discusses the issues involved in using simulation modeling for mine production system design.

Jan 1, 2002

By I. Andras

The paper deals with the application of artificial intelligence methods in assessing the effectiveness of longwall shield support. A fuzzy sets based method is used to derive response surfaces/curves representing the dependence between basic parameters of the shield, as the initial setting pressure and the stiffness on the response metric, i.e. the convergence and load increase during a working cycle.

Jan 1, 2008

By S. El-Mofty, P. Zhang, N. A. Khalek

This article reviews different technologies used for beneficiation of siliceous and calcareous phosphate ores of different origin. The review sheds light on recent trends suggested for solving problems associated with separation of different impurities from phosphates. Applications of recently modified flowsheets as well as new reagents in the flotation of phosphate ores of sedimentary origin are highlighted.

Jan 1, 2003

By W. J. Halvorsen

Means for minimizing the disadvantages of thermal drying are suggested. The other ap¬proach of substituting other techniques in place of thermal drying is also discussed. Recent devel¬opments in fine coal screening dry down to 3.2 mm (0.125 in.) and 2.0 mm (10 mesh) offer an econom¬ical means in certain cases.

Jan 1, 1988