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By A. Founie

The United States continues to be the world’s leading producer and consumer of diatomite. Production of diatomite in the United States during 2005 was estimated to be 653 kt (720,000 st). This was a 5-percent increase compared with 2004. The value of processed diatomite in the U.S. was about $179 million in 2005. Production was from six companies with 12 processing facilities in four states. California and Nevada were the principal producing states. They accounted for about 70 percent of U.S. production in 2005. U.S. diatomite exports were about 144 kt (159,000 st). Imports were negligible. The internal structure and chemical inertness make diatomite an excellent raw material for filtration, absorbent and filler applications. Filtration, especially the purification of beer, liquors and wine and the cleansing of greases and oils, continued to be the largest end use for diatomite. Other applications include the removal of microbial contaminants, such as bacteria, protozoa and viruses in public water systems, and the filtration of human blood plasma. The use of diatomite as fillers and in pharmaceutical applications, including the filtration of human blood plasma, continues to increase as has its use as an insecticide base and as pozzolan. The relative rank of end uses of diatomite were filter aids, 75 percent; fillers, 11 percent; absorbents, 7 percent and other (mostly cement manufacture), 7 percent.

Jan 1, 2006

By Clinton Strachan, Rob Dorey

10.1 INTRODUCTION This chapter presents considerations which should be applied to heap leach pad site selection, site evaluation, and design, relative to the geotechnics of the site and ore. 10.1.1 General Guidelines are presented covering the topics encountered in design and construction of heap leach faci1ities. Because geotechnical characteristics vary from site to site, not all geotechnical topics associated with a specific heap leach facility are presented, and there may be exceptions to some of these guidelines. The general features of a heap leach facility (from Chapter 1) to be discussed in this chapter are: • Leach pad (including leach pad foundation and liner); • Heap; • Solution storage faci1ities (for pregnant and barren process solutions) ; and • Solution collection facilities (which collect and convey solutions in the heap and convey them to solution storage facilities). These general features are illustrated in Figure 10.1. Liners for these facilities are discussed in Chapter 11. Solution application systems and the sizing aspects of solution storage facilities are discussed in Chapters 6, 7, and 12. The general features listed above are constructed with and overlie naturally occurring materials (such as ore, borrow soils, and subsurface soils and rock). These natural materials are relied upon to perform in an acceptable manner as a component of the leach facility (such as the liner, drain material, and foundation).

Jan 1, 1988

By Hocking G

For some underground structures, the use of the plane strain assumption in stress analyses may not be justified. The finite element method and photoelasticity have been used to obtain complete 3-D solutions, but, for various reasons, neither method has found universal use. The boundary integral equation method (B.I.E.M.) can be more efficient and economical than the finite element method for 3-D problems involving large volume to surface area ratios. A B.I.E.M. program developed for calculating stresses and deformations in infinite elastic media has been used to determine the 3-D distributions of stress around T- and Y- junctions of circular tunnels in stress fields in which the ratios of horizontal to vertical stress are 0, 0.33, 1.0 and 2.0. For the T- junction considered,stress concentrations at the intersection are approximately twice the plane strain values. Except where horizontal field stresses are high, the stresses in both tunnels approximate the plane strain values at about two tunnel diameters from the point of intersection of the tunnel centre lines. The stresses in the two branches reach those for the corresponding plane strain, two parallel tunnel case two diameters from the point of intersection of thq inner tunnel walls. Very high stress concentra- tions occur in the pillar of rock between the inner tunnel walls near the point of intersection.

Jan 1, 1976

THE opening session was held on Tuesday evening, October 23d. Mr. J. F. Lewis, on behalf of the local committee of arrangements, made a short address of greeting to the members assembled, and then introduced Gov. A. H. Holley, of Lakeville, Conn. Gov. Holley addressed the Institute as follows : Gentlemen, we give you cordial welcome to a mining, manufacturing, and agricultural country, of which we are not a little proud. We welcome you as an association, and as individuals. We invite you to an inspection of our resources, and to our methods of improving them. We appreciate the results of your efforts in past years, and we anticipate good from your advice and counsel in the future. You are in the vicinity of some of the oldest mining and manufacturing operations in iron in our country. It will be our pleasure to conduct you to a mine which was worked for more than a half century before our country achieved national independence, and to point out to you the spot where the products of this mine were wrought into cannon and shot during the progress of our Revolution. We can show you also a far larger area of mining country than was supposed to exist in this vicinity at that early day. There are, within a radius of thirty miles from this spot, ten mines at least that have been extensively worked, and there are as many more that have been occasionally worked, with a fair degree of success. All the mines that are wrought to any extent produce excellent qualities of iron, while many of them in various combinations produce as good material for the manufacture of steel, car wheels, axles, and many other purposes, as can be found in any country. The old Salisbury iron retains its reputation for tensile strength unsurpassed, when made entirely from the ore of the old mine. The progress that has been made in the development of these mines since the days of the pickaxe, when the product was transported in pounds upon horseback, to those of the steam-engine, which now moves hundreds of tons per day, presents, indeed, a

Jan 1, 1878

The opening session was held on Tuesday evening, October 23d. Mr. J. F. Lewis, on behalf of the local committee of arrange ments, made a short address of greeting to the members assembled, and then introduced Gov. A. H. Holley, of Lakeville, Conn. Gov. Holley addressed the Institute as follows: Gentlemen, we give you cordial welcome to a mining, manufac turing, and agricultural country, of which we are not a little proud. We welcome you as an association, and as individuals. We invite you to an inspection of our resources, and to our methods of im proving them. We appreciate the results of your efforts in past years, and we anticipate good from your advice and counsel in the future. You are in the vicinity of some of the oldest mining and manufacturing operations in iron in our country. It will be our pleasure to conduct you to a mine which was worked for more than a half century before our country achieved national inde pendence, and to point out to you the spot where the products of this mine were wrought into cannon and shot during the progress of our Revolution. We can show you also a far larger area of mining country than was supposed to exist in this vicinity at that early day. There are, within a radius of thirty miles from this spot, ten mines at least that have been extensively worked, and there are as many more that have been occasionally worked, with a fair degree of success. All the mines that are wrought to any extent produce excellent qualities of iron, while many of them in various combinations produce as good material for the manufacture of steel, car wheels, axles, and many other purposes, as can be found in ally country. The old Salisbury iron retains its reputation for tensile strength unsurpassed, when made entirely from the ore of the old mine. The progress that has been made in the development of these mines since the days of the pickaxe, when the product was trans ported in pounds upon horseback, to those of the steam-engine, which now moves hundreds of tons per day, presents, indeed, a

Jan 1, 1879

By William B. Phillips

In connection with the address of our late President, Mr. Joseph D. Weeks, delivered at the Pittsburgh meeting, in February, 1896,* I venture to believe that a circumstance which came recently to my notice may possess some historical interest. Several years ago I spent some months in Western Kentucky

Jan 1, 1899

By Paul D. Young, Michael J. Allan

"The Con Mine has been producing gold continuously since 1938. In 1990 laboratory and pilot plant investigations began into the use of pressure oxidation for treatment of an arsenic trioxide waste product from two previous roaster operations on the property. This led to the construction in 1992 of a 96 ton/day plant to treat a mixture of arsenic waste and flotation concentrate from the existing mill. The plant was commissioned in the fall of 1992.This paper describes experience gained in the commissioning and initial operation of the plant. The unique aspects of treating a hazardous waste product are described including special operating procedures to satisfy environmental and employee safety concerns. The paper further describes modifications made to the process flowsheet, to operating procedures and to materials of construction in the early months of operation."

Jan 1, 1994

PREFACE During the past year, the Council of the SAIMM undertook a major strategic-planning exercise to review all its current activities, and to redefine its scope and objectives in the light of changing circumstances. The following are the four main concerns that prompted Council to take stock of the situation. (1) Over the past five years, the SAIMM has become heavily involved in a variety of new activities. (There are many examples, of which the expansion in book publications and the establishment of physical metallurgy as a third major discipline with its own colloquia and schools are perhaps the most important.) While these new activities have considerably broadened the SAIMM's scope, they have resulted in a significant increase in the day-to-day workload of the President, Office Bearers, and Council members, and of the secretarial staff based at Kelvin House.

Jan 1, 1986

By Pierre de P. Ricketts

Having had occasion while in Europe during the past summer to visit some of the foreign mints and assay offices connected with the same, I thought a brief description of the general process of coining employed, and such items connected with assaying as were new, might prove interesting to the Institute. The principal foreign mints are: the Royal Mint, London; and the mints in Paris, Brussels, Utrecht, Berlin, Vienna, Copenhagen, St. Petersburg, Stockholm, Madrid, Milan, Rome, and Constantinople. My time only permitted my visiting a few of the principal and largest given in the list, and for a description of the remainder I am indebted to the kindness of Mr. James M. Napier, who in company with the deputy master, and chemist of the Royal Mint, made a complete inspection of all the European Mints in 1870.

By D. D. Runnells, G. A. Doyle

The quality of water in mine pit lakes depends in part on the physical limnology, including such factors as thermal and chemical stratification, turnover and the development of anoxic conditions with depth. Limnologic data collected from four existing pit lakes in Montana and Saskatchewan indicate that pit lakes develop a thermocline (temperature stratification) in the upper 10 to 30 m (33 to 100 ft) of the water column. Two of the pit lakes, 26- and 55-m (85and 180 ft) deep, undergo seasonal turnover of the entire water column, whereas two deeper pit lakes, 110- and 240-m (360- to 790 ft) deep, undergo seasonal turnover of only the upper portion of the water column. In the deeper lakes, seasonal mixing does not extend through the entire water column, and a distinct chemocline develops with depth.

Jan 1, 1998

By T. Egleston

In the year 1881 I presented to the Institute two papers containing the resnlts of researches on gold, in which I endeavored to make plain some of the causes of the losses in the working of gold-ores. Since that time I have continued this investigation at intervals with the following results. In the papers previously presented to the Institute I made no attempt to make compounds containing more than two substances. Since then I have endeavored to make more complex compounds. The experiments consist in fusing mispickel free from gold with a certain amount of metallic gold, and experimenting with that; also fusing the same mineral with sulphide of antimony, and fusing iron pyrites with gold and compounds of antimony. The mixture was made with mispickel taken from a vein not far from Stamford, Conn., absolutely free from gold. It was fused

Jan 1, 1884

By G. A. Doyle

The quality of water in mine pit lakes depends in part on the physical limnology, including such factors as thermal and chemical stratification, turnover and the development of anoxic conditions with depth. Limnologic data collected from four existing pit lakes in Montana and Saskatchewan indicate that pit lakes develop a thermocline (temperature stratification) in the upper 10 to 30 m (33 to 100 ft) of the water column. Two o f the pit lakes, 26- and 55-m (85 and 180 ft) deep, undergo seasonal turnover of the entire water column, whereas two deeper, pit lakes, 110 and 240-m (360- to 790 ft) deep, undergo seasonal turnover of only the upper portion of the water column. In the deeper lakes, seasonal mixing does not extend through the entire water column, and a distinct chemocline develops with depth.

Jan 1, 1997

By C. W. Schulties, W. J. Mallio, L. J. Petrovic, J. A. L. Campbell

Roof control comprises about 35% of direct and indirect underground mining costs. In addition, difficulties in estimating roof control costs for new areas lead to the greatest uncertainties when negotiating coal contracts. And obviously, coal cannot be mined if the roof can't be held. Accordingly, there are strong incentives to attack this problem on as many fronts as possible. One successful geological modeling technique for predicting future roof conditions was recently applied at Peabody Coal's Simco mine No. 5, located in Coshocton, Ohio. Benefits derived from it included: - A better identification of areas where poor safety conditions may be encountered. - Improved roof control cost estimates for contract negotiations. - Estimates of time-duration while mining in bad roof areas. - Labor and materials cost predictions in an existing mine. - Productivity increases through prior knowledge of areas to avoid.

Jan 10, 1975

Book Review Sampling in the mineral and metallurgical processing industries. London, Institution of Mining and Metallurgy, 1973. 65 pp. illus. £5. The seven papers presented at a special meeting of the Institution of Mining and Metallurgy held in London in July, 1973, have been brought together under the above title.

Jan 11, 1973

By Fred C. Drury

The Explosives Engineer's concern for personnel training in the safe, efficient and effective use of explosives materials has grown in recent years. Available training options have also grown. Today's options include off-site training seminars and in-house training departments, both of which represent significant cost to the smaller producer.

Jan 1, 1981

By Pamela Binstead

The Institute's ninetieth anniversary was celebrated in grand style with a banquet and dance in the ballroom of the Carlton Hotel in Johannesburg, on 22nd March. Some six hundred and thirty members and guests filled the room to capacity, and many remained to enjoy the festivities until well past midnight.

Jan 1, 1985

By William G. Kegel

Problems involved in putting the gob back underground in modern deep mines we dealt with. In particular, the problems associated with haulage of the gob back to the mine, the blown gob method of dispersion underground, and handling the refuse as slurry are discussed. Some alternative methods of disposal are presented.

Jan 1, 1976

Environmental impact and rehabilitation on completion are primary considerations in obtaining approval for mine projects from government authorities.This paper focuses on the planning and commencement of rehabilitation during the mining of an open cut mine (Hedges Gold Mine) in an environmentally sensitive area in the southwest of Western Australia.

Jan 1, 1992

The twin iron ore islands of Cockatoo and Koolan are located in the spectacular setting of Buccaneer Archipelago off the Kimberley coastline of WA.Cessation of ore shipments from Koolan in 1993 ended 42 years of continuous mining activity which began with the first shipment of ore from Cockatoo in 1951.

Jan 1, 1993

By E Emery Gray, Gary Ard

Each year when hundreds of Engineers and Specialists in the explosives industry meet for the SEE Annual Conference, new ideas are exchanged and new business relationships formed. Harbert Construction Corp. and EGA, Inc., a company specializing in drilling and bIasting, formed such a relationship through mutual interest in such a manner.

Jan 1, 1981