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By Thomas Jancic

Two of the open-pit, copper-molybdenum mining operations of Duval Corporation are located in the foothills of the Sierrita Mountains approximately 30 miles southwest of Tucson, Arizona. In March 1959, mining from a moderate sized porphyry deposit known as the "Esperanza orebody" was begun at a rate of 10,000 tons of ore per day. Some five years later, a sizeable group of mineral claims west of Esperanza became available to Duval. Earlier exploration and development drilling in this area by others indicated an orebody of greater size but lower tenor than that of Esperanza. A drilling program conducted by Duval not only verified the results of the prior drilling but in addition, revealed a continuation of the mineralization to the south and east. Thus was developed the Sierrita orebody. Open pit design delineated 414 million tons of ore containing an average copper content of 0.35 percent and a molybdenum content of 0.036 percent. In April 1966, the office of Emergency Planning authorized General Services Administration to undertake a program under the Defense Production Act to en¬courage additional domestic production of copper in the interest of national defense. Duval's Sierrita Project was brought to GSA's attention in May 1966 on November 28, 1967, an agreement providing for the development of the Sierrita Property was consummated with GSA. In March 1970, the first copper-molybdenum concentrates were produced in the 72,000 tons-per-day concentrator. Pre-production stripping exceeded the scheduled 105 million tons despite the comparatively short lead time available to equip the mine, build the mine plant facilities, and staff the technical, supervisory, and labor forces. Shortly before the first concentrates were produced, plans were being formulated for a program to increase processing capacity by approximately 15 percent, which entailed increasing overall mining capacity by approximately 50,000 tons per day. This program is scheduled for completion early in 1971.

Jan 1, 1971

By R. E. Pennington

My subject this morning is coal liquefaction technology. Actually, coal liquefaction involves a number of technologies in a very complex system. The first slide shows the major components of such a system with arrows to indicate appropriate flows. The components are the facilities for coal feed preparation and handling; the coal hydrogenation or base liquefaction section; facilities for product separation and recovery, and in addition, facilities for the production of hydrogen from coal-based sources. A very rough break- out of the investments involved in these areas is given at the bottom of the slide. Investment is spread about equally among the three areas of operations Another way of looking at it is that the investments in what might be called support facilities are of the same magnitude as the base investment in the hydrogen facilities. Therefore, it is appropriate in a discussion of coal liquefaction technology to treat it as a system composed of a number of technologies. The next slide lists the various functions in the feed preparation section along with an indication of technology status. Storage, crushing, grinding, drying of coal all have been in commercial practice for a number of years. The slurrying and pumping of coal at least in water slurries, is practiced commercially also. The heating of coal slurries in oil to high temperatures under pressure is not in commercial practice and development and testing is going on by a number of people in this area. Some rather complex phenomena occur when coal oil slurries are heated to high temperatures.

Jan 1, 1975

By M. S. Moats

In the 1990?s, Técnicas Reunidas developed the Modified ZINCEX® Process to recover zinc from ores and secondary materials. The heart of this process was the use of solvent extraction to produce purified zinc electrolyte instead of traditional zinc dust cementation. This development was commercialized by Reunion Mining and Anglo American for primary ore at the Skorpion mine in Namibia with the first SHG zinc produced in May 2003. Horsehead Corporation through Horsehead Metal Products, Inc., its wholly owned subsidiary, is presently commercializing the MZP for the treatment of Waelz oxide. This paper will review open source information about the lessons learned and process modifications that have occurred at Skorpion over the past decade. It will also provide an update on Horsehead?s facility being constructed in Rutherford County, North Carolina.

Feb 23, 2014

By C. E. Golson

The preparation of aggregates is a form of mineral processing which has been taken for granted for many years, mostly because of its lack of glamour when compared to the winning of metallic minerals from their ores. Many of the processes and equipment now used in the metallic mineral processing industries originated in the more prosaic preparation of aggregates. 'Their adaptation to metallurgical processes has led to developments both in their design, and in their use. Modern practice, has been so exacting in its demands that, in many cases, this improved technology is finding new applications in the very industry in which it originated the mineral aggregate industry, The low cost requirements, large tonnage capacities and complex specifications which govern the acceptability of its products have node modern aggregate processing a much different art than it was one or two generations ago. The basic conditions which govern the type and quality of mineral aggregates were presented in an addendum to a paper given at the San Francisco Meeting in 1959 by one of the authors.

Jan 1, 1961

By Pablo Hadzeriga

There are two places in the world where potash, trade name for potassium chloride, is economically recovered from naturally occuring brines by solar evaporation. One is at the Dead Sea and the other at Wendover, Utah. American Potash and Chemical at Trona, California recovers potash from natural brines, but uses fuel to accomplish evaporation. Under proper meteorological conditions the use of solar evaporation might be desirable from the economical standpoint. Of course, this may not be true when, if by artificial evaporation, a group of very valuable salts are recovered. This is the case of the American Potash operation at Trona. Solar evaporation has its limits. The working temperature is low. We may say, just to cover most areas of the world where solar evaporation may be practical, that it will take place between 18°C and perhaps around 45°C. In most cases the average working temperature expected will be around 25°C.

Jan 1, 1963

By William H. Pelton

The presence of high-grade massive sulphides near York Harbour, Newfoundland has been known since the turn of the century. In the early 1900's a small, massive-sulphide deposit was worked by conventional hand methods and yielded about 100, 000 tons of high grade copper-zinc ore. Since that time, a number of mining companies have held options on the property and an exploration adit was driven along the fourth level of the original mine. Underground drilling revealed several additional massive sulphide lenses in the range of 10, 000 to 60, 000 tons (Fig. 1). The problem facing Long Lac Mineral Exploration Ltd. when they undertook an option on the property in 1969, was to outline any possible extensions to the known sulphide lenses which were outside the reach of underground drills and to search for new ore deposits which might double the known reserves into a feasible project for development. GEOLOGY AND PHYSICAL PROPERTIES: The geology is typical of many massive sulphide deposits within volcanic rocks in the Canadian Shield. The sulphide pods appear to occur along a complex andesite-basalt contact. Identification of the two volcanic types is difficult since they are almost the same colour. The most direct means of identification is by the slight difference in their magnetic susceptibilities. Pyrite, chalcopyrite and sphalerite are the main minerals in the sul¬phide lenses. The ore is massive, differing in density from the host rock by at least 1.0 gm/cc. There is little pyrrhotite or magnetite associated with the sulphides, so there is no appreciable difference in magnetic susceptibility between the sulphides and the basalt. Also, there is no alteration halo around

Jan 1, 1971

By Girish Roy, Robert Goodfellow, Angel Del Amo, Bingzhi Yang

Designing and constructing tunnels in seismic prone areas present unique challenges to both designers and contractors. The Westside Purple Line Extension Project– Section 3 in Los Angeles requires crossing an active fault that may subject the tunnels to extreme structural demands. In order to ensure that the linings will safely accommodate the fault movement, a revolutionary composite section—steel plate embedded in the intrados of the precast concrete segmental tunnel lining was finally selected. Additionally, continuous expansion steel plates over the circumferential joints will be installed to mitigate the potential opening of the circumferential joints.

Jun 13, 2021

By Kenneth W. Torpey, James G. Ball, Richard F. Flanagan, David S. McAllister

INTRODUCTION Under a Federal grant by the Urban Mass Transit Administration (UMTA) (80%), and sponsored by the State of New York (200), Niagara Frontier Transportation Authority is constructing a 10.3 km (6.4 mile) light rail rapid transit system in Buffalo, New York. The $450 million project, which began construction in the Spring of 1979, is unique in rail transit alignment designs in the U.S.A. and the first predominantly underground light rail system in North America. The Buffalo project is unique in that the first phase of the expandable system follows the alignment of Main Street and is on the surface in a proposed 1.6 km (1.0 mile) pedestrian mall in the downtown business district. The alignment then progresses northward into a cut-and-cover portal and standard double-box configuration for 2.74 km (1.7 miles) at a depth of 9.1-10.7 m (30-35 ft) and subsequently drops into bedrock at depths of 18.3-27.4 m (60 to 90 ft). The 5.63 km (3.5 mile) rock tunnel section consists of two single tunnels 4.88 m (16.0 ft) nominal finished diam. and includes five stations. The rock tunnel line section was divided into a north and south contract of 2 316 m (7,600 ft) and 3 243 m (10,640 ft), respectively. Due to the existing surface facilities and the future station locations, the line tunnel contracts differed considerably in their shaft access

Jan 1, 1981

The Anshan Iron and Steel Co. (AISC) broke its steelmaking design capacity in 1978, bringing its total production of steel products to 6.86 Mt. Located south of the industrial city of Shenyang, Liaoning Province, in northeastern China, it is by far China’s most important iron and steel complex, ranking twentieth among world centers. The complex represents a unique blend of old ecluipment and new ideas for increased production and improved products. Under a state plan, the Chinese hope to raise capacity to almost 15 Mt/a in the future. Originally started by the Japanese in the early 1920s, Anshan has had a rather turbulent 60-year history. It was disassembled by the Soviets after World War II, only to be reassembled by them in the 1950s. Production was also suppressed during the Cultural Revolution. Since the present-day organization, AISC, emerged, the center has experienced progressively improving conditions as well as increased production. Today, the center includes 10 blast furnaces, 24 open hearths, and two basic oxygen units, designed for 7 Mt/a ironmaking and 6.5 Mt/a steelmaking. In addition, it has six batteries of cokemaking facilities with combined 4.4-Mt/a capacity. Solid Iron Resources Anshan’s iron resources consist of a proven reserve base of over 7 Gt of 30~0 Fe, according to Kao Yang, president of the Anshan Iron Mining Co., a subsidiary of AI SC, Most of that, he continued, is amenable to surface mining. Five major mines located to the north and northeast of the city of Anshan are the principal iron ore producers. These mines trend in a somewhat circular manner and combined, represent an estimated 28.6 Ylt/a of ore capacity. In addition, some 2.2 Gt of magnesite, a necessary ingredient in steelmaking, are also part of the reserve base, according to Kao. Annual production is around .2 Mt/a of 47% magnesite, well over the steelmaking center’s annual requirements, Excess production is shipped to other steel-making centers. The largest of Anshau’s open-pit mines is the Chitashan operation with a design capacity of 8 Mt/a. Ore reserves here are well over a billion tons of 30% Fe. Earlier plans to expand production at this mine to 15 Mt/a, with the help of US Steel, have been temporarily shelved. The other mines in the district and their rated design capacity are: Kungchangling, 7 Mt/a; Donganshan, 6.4 Mt/a; Dakushan, 4.2 Mt/ti; and Yenchienshan, 3.0 Mt/a. The Kungchangling mine is the richest in terms of ore grade at 6076 Fe. Reserves are somewhat smaller at 100 Mt. The unit also operates a small shrinkage stoping operation. Ore grade at the other mines is usually 30-327. Fe. Llost mines operated at reduced capacity during 1979 owing to a natural gas shortage at the mills. The general

Jan 3, 1980

By C. C. Muir

At the outset, I believe reference should be made to comparatively recent world developments in copper which have an important bearing upon the Canadian position. COPPER SITUATION No one can doubt the marked change for the better compared with not so long ago when less than adequate attention was paid to marketing and to uses of the metal. I need not show you graphs of world copper prices, which except for relatively brief periods and war conditions were, until about three years ago, not unlike the topography of the Canadian Rockies. There remain, of course, some non-industry factors who yearn for the old days of "roller-coaster" copper prices.

Jan 1, 1964

By E. Allen Wendt

It is both a great pleasure and something of a challenge for me to have this opportunity to address a gathering encompassing such a wealth of expertise in the minerals field, It is particularly challenging because I have been asked to turn your attention from the relatively glamorous subjects of gold and money to the more mundane questions of our International commodity policy and the place of buffer stocks in that policy. However, these questions may be of more immediate importance for our economic interests at home and Abroad. I can testify that the problems affecting international commodity markets and the possibility of international action To resolve those problems are matters of real concern to Washington as well as to your industries,

Jan 1, 1978

By J. R. Hoskins

Method - A direct approach to instrument users, initially by letter and later by telephone or personal contact was made. The resultant data was compiled to give specific use information on the seven instruments. During the course of the study attempts to evaluate the Griswold Gage were abandoned when it became apparent that the gage was not being commercially produced. One company is developing the gage for its own use. The information presented is the result of over 1200 inquiries.

Jan 1, 1973

By Bill A. Hancock

In Situ leaching for the recovery of uranium from low grade sandstone deposits is one of the newest technological advances in the mineral industry. It is rapidly developing into a commercially feasible mining system which has economic, environmental, and social advantages over conventional mining systems. Because of the current uranium shortage, development of In Situ leaching into a sophisticated system has gained new impetus. In Situ leaching will become an important mining technique in the future, which will greatly help to supply uranium for our nation's energy heeds. In this paper, I will be giving an overview of the merits of the system, as well as the technology, problems, and research in solution mining of uranium.

Jan 1, 1977

By Ben Blaschuk

The Bagdad solvent extraction plant was commissioned in 1969 and was the second solvent extraction-electrowinning (SX-EW) operation to be built following the Ranchers Bluebird SX-EW plant near Miami, AZ. The current operation still resembles its original form, with four independent sections that run in parallel with each consisting of many long and narrow settlers. Through its 40-year history, the Bagdad SX circuit has experienced a range of pregnant leach solution flows and grades. The unique design of the Bagdad circuit has allowed for numerous configuration changes to accommodate the changing operational conditions, while maintaining an extraction recognized in the industry as excellent.

Jan 1, 2011

By Betty Gibbs

The Ore Body Modeling and Mine Planning Worshop, sponsored by the Society for Mining, Metallurgy, and Exploration, Inc. (SME), was held Feb. 22-24, 1991 before the SME Annual Meeting and Exhibit in Denver, CO. More than 40 people from mining companies, government agencies and universities attended. Eight vendors of integrated ore body modeling and mine planning software attended and presented the results of problem sets given before and during the workshop. They were: [ ]

Jan 1, 1991

By R. K. Komarek, F. E. Jr. Briber, G. M. Hanson, Fred D. DeVaney, J. H. Blake, C. L. Matson, T. E. Ban, N. E. Shields, R. D. Frans, R. B. Greenwalt

Metallurgically, the term agglomeration is used to describe processes whose goal is to form balls, briquettes, nodules, flakes, or other sized shaped particles from loose, usually fine, incoherent particles. In practice it includes such varying processes as the briquetting of coal dust and other substances, the balling and induration (heating) of such nonmetallics as cement, fluorspar, lightweight aggregates, etc. It includes such widely used processes as the sintering of nonferrous concentrates, such as those copper, lead, zinc, etc. The agglomeration of specific nonferrous metal concentrates is discussed in detail in the section of this handbook devoted to that particular metal. Agglomeration processes are of particular value to the iron and steel industry where the nature of the primary reduction process, the blast furnace, requires for best results a burden essentially free of fines. This is a change that has taken place since about 1960. Prior to that time many fine unsized ores were fed to the furnace. The development of the pelletizing process gave to the industry a chemically controlled closely sized product that increased the produc¬tion rate and reduced the costs so much that unsized fines are seldom used in modem furnaces. Steel plants produce many fine sized waste products such as fine dust (fine ore coke and gangue) and mill scale. These products, which have a valuable iron content, are usually sin¬tered directly at the plant for reuse. Fine sized ore concentrates are usually pelletized at the mine and shipped as pellets to the steel plant. Common practice in some areas producing natural high grade ores is to screen the ore at the mine to about 3/8 in. The oversize is shipped "as is" and constitutes blast furnace feed. The / in. may be shipped to the steel plant where it may be sintered or otherwise agglomerated. At some mines the fines may be pelletizied prior to shipment. With the development of large ocean ore carriers, and with the transportation of slurried concentrates or fines, a trend has developed of constructing large pelletizing plants or other types of agglomeration plants near large consumption centers (i.e., in the Netherlands or Japan) where ores of many types are brought together, ground if necessary, blended, and agglomerated. As an indication of tonnages of agglomerated materials produced, for iron materials alone (the largest share of the total) production in 1970 in the U.S. was Million gross ton Sinter 40.7 Pellets 43.1 Briquettes, nodules, & others 0.1 Total 83.9 During the 1960s, U.S. production of sinter rose from 40.3 million gross tons in 1961 to a high of 48.7 million in 1964, then settled back to almost the 1961 figure in 1970. Pellet production rose steadily from 14.4 million gross tons in 1961 to the 59.9 figure for 1975. Worldwide, sinter production in 1966 was estimated at 340 million mt (mainly in Europe, Russia, Japan, and the U.S.) and pellet produc¬tion the same year at 64 mt (primarily Canada and the U.S.). World pellet production capacity rose to 200 million tons in 1976.

Jan 1, 1985

By Richard A. Levins

The imposition of non-market regulations, such as the proposed SO2 standards for coal combustion, will typically lead to less efficient (thus more costly) production in a free enterprise system. For the coal industry these increased costs will occur in several ways, among which are mining less accessible low sulfur reserves and transporting low sulfur coal to distant markets. There are, of course, social benefits of reducing the S02 emissions from the use of high sulfur coal. The social benefits include decreased health risks, reduced damages to property, and certain unmeasurable benefits associated with the aesthetic appeal of clean air. Proponents of Federal S02 standards argue that the benefits gained from reduced emissions will exceed the costs borne by the coal industry and society in general in meeting the regulations. The purpose of this paper is to investigate the degree to which costs of meeting future energy demands from coal will change under different sulfur standards. No attempt is made to estimate the benefits of imposing regulations. Specifically, the impact of SO2 standards on the private costs of meeting regional coal demands, the competitive positions of the nation's major coal producing regions, the degree to which strip mining as opposed to underground mining will be feasible, the amount of coal being processed, and the amount of coal transported over major rail routes will be analyzed.

Jan 1, 1976

By Irwan Halim, Bhoshaga Mitrran Ravi Chandran, Kevin Huynh

Tunnel segmental lining design constitutes a significant iterative process where modeling and numerical analysis are factors in deciding the number of segments, their dimensions, gasket placements, as well as the locations of dowels and bolts. Consequently, these modifications lead to revisions in the final drawing details. However, the current tunnel engineering practices lack systematic solutions that effectively bridge the gap between the iterative design process and efficient visualization of completed drawings due to the time- consuming nature of redrawing. This paper presents a pioneering application of AI-driven solutions including using Autodesk's API, for the Northside Interceptor Tunnel (NSIT) Project. It showcases the automation of drawing design and the real-time visualization of modifications, thereby streamlining the drawing process.

Jun 23, 2024

By CHONG WEI, TATYANA KATSAGA, DEREK APEL

This study provides an effective determination process of the interface microstructural parameters in the numerical modelling of the mechanical interaction between two different geomaterials involved with frictional-bonded interfaces, such as the interaction between backfill columns and the surrounding rocks, or the soil-structure interaction, by using the coupled finite-difference and discrete-element (FD-DE) method. Three-dimensional numerical direct shear tests were conducted on the coupled FD-DE model of the combined rock-cemented rockfill (R-CRF) specimens with the frictional-bonded interface. With the microstructural parameters determined, the macro-mechanical properties of the interface of the coupled model were calibrated to well fit with the theoretical values of the combined specimen under the direct shear condition assumed according to the Mohr–Coulomb strength criterion. Evident elastoplastic shear behaviour was observed on the interfaces, and excellent agreement was attained between the shapes of the theoretical and simulated shear stress-displacement curves of the coupled models at different servo-controlled normal stresses. Particulate-scale force chains inside the DE model of the CRF specimen were highly consistent with the force contour on the FD model of the rock specimen, demonstrating the shear stress evolution of the coupled model at different shear displacements. Parametric studies verified the effects of the deformation properties of the interface parallel bonds on the shape of shear stress-displacement curves of the coupled models. The test results validated the feasibility and rationality of the coupled FD-DE method for modelling the combined specimens with frictional-bonded interfaces or joints. Furthermore, this study provides valuable numerical modelling experience for investigating the shear behaviour at the interface between cemented backfill columns and surrounding walls by using the coupled FD-DE method.

Nov 2, 2021

By Henry N. McCarl

The New England States form the most northeastern portion of the continental United States and include Connecticut, Rhode island, Massachusetts, Vermont, New Hampshire, and Maine. These states have an aggregate population of over 10.5 million people, and an average annual population rate increase of about 1.3%. A great deal of new construction is required each year to meet the increasing demand for new homes, roads, offices, factories, and warehouses. Yet, prices of construction materials such as blocks and concrete are generally higher in New England than in other well populated areas of the United States. This is an indication of local demand being somewhat greater than supply, an atmosphere conducive to new developments in the production of construction materials. One such field of development is the rapidly growing Lightweight Aggregate Industry. Recent construction in Boston has used a great deal of lightweight aggregate. New structures using lightweight aggregate in lightweight concrete include the following: M.I.T.'s 20-story Earth Science Center and 17-story Married Students Housing Project Prudential Life Insurance Center, West End Redevelopment Project at Charles River Park, Hotel Americana, and the British-owned 33-story office building at 50 Pearl Street.

Jan 1, 1964