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By G. Aggistalis, N. Kazilis, C. Rawlings, N. Rachaniotis, S. Raptopoulos, M. Knights, R. Game

The Egnatia Odos (Odos meaning road) is one of Greece’s largest ever highway construction projects and one of Europe’s most important. The Highway will assist in the connection of the Greek Ionian/Adriatic Coast with Turkey and the Black Sea reviving an historic Roman alignment “Via Egnatia” connecting Rome to Constantinople (now Istanbul). There are 74 twin tunnels (60 bored and 14 cut-and-cover) with lengths ranging from 160 m (175 yd) to 4,600 m (5,031 yd) and 100 m (109 yd) to 270 m (295 yd),respectively. The complex geology and resulting physical geography have had a major influence on both the design and construction of these tunnels. This paper describes the management, design and construction challenges of these numerous tunnels.

Jan 1, 2005

By C. T. Baroch

The purpose of this report is to describe the design features and techniques used in operating a plant capable of producing about 1,500 pounds of titanium metal per day. The process used was based on the reduction of titanium tetrachloride with magnesium, a modification of what is generally known and spoken of as the Kroll process. Sponge metal crushed to melter's specifications was the end product of the operation as conducted. The report is divided into sections covering general plant layout and the major unit operations. These, in turn, are each divided into discussions of the equipment, operating procedures, and typical results. Descriptions are given in more detail than is generally expected of a technical report. During 1953 and 1954 over 130 engineers and businessmen, officially representing some 80 industrial, chemical, end engineering firms, visited the operating plant, and their questions, which indicated a serious interest in details, have served as a guide for the material contained in this report.

Jan 1, 1955

Investigation on Multicomponent Semi-Autogenous Grinding

Sep 13, 2010

By A. C. Moorgas, J. Divall

This study investigates the feasibility of using waste iron slag, the by-product from a mineral sands processing works, in road construction. The study includes the different options investigated for the treatment of a leachate that is produced during the cooling of the iron slag, prior to processing. It also reviews the reasons for choosing the current treatment option that is being trialed. Cooling the iron slag with water results in the formation of a leachate with a high pH and high sulphide concentration. This leachate can seep into the ground and, over time, it will contaminate the ground water. A system was designed to collect and treat the leachate to prevent contamination of surrounding natural water sources. Numerous leachate treatment options were investigated to find cost effective method of treatment After cooling, the iron slag is passed through an iron recovery plant and the unsaleable product is placed on a dumpsite. Rain percolates through the dumpsite, which can result in the formation of a leachate that can contribute to a contaminated plume. After extensive testwork, it was found that the dumpsite, which was leached of contaminants, could be screened and used as a G5material (specifications in Table II) in road construction. The initial challenge was to establish that this material was environmentally safe for use in this particular application. Approval from the Department of Water Affairs (DWAF) was required for the testwork and then for the long-term use of this material in the construction industry. The following challenge involved establishing a market for the material. Construction companies in the area were reluctant to change to a new product that was not naturally occurring. The economics of this project are extremely sensitive to transport costs and hence only projects within a specified radius can be supplied with the Black Top Gravel (BTG). This project is not are venue generator, but it does save the money that would be required to manage the dump, and it reduces the closure costs.

Jan 1, 2003

By C. Patel, George H. Hope

"INTRODUCTIONThe Hemlo area is located in Northern Ontario, some 350 km east of Thunder Bay along highway 17. Hemlo is Canada's largest, recent discovery of gold ore. Three companies, Lac, Noranda, and Teck are currently developing mines and processing facilities in the area. A combined milling capacity of approximately 10,000 tonnes per day will ultimately be available in the area. The gold yield will be between 750,000 to 1,000,000 ozs. per year. This will slightly more than double Ontario's gold production but only represents 2.5% of the total world gold production.Lac Minerals Ltd. is substantially committed to the gold mining business. Lac currently operates four (4) gold mines and mills and produces 300,000 ozs. per year. Lac's Hemlo development will put the company in the position of number one gold producer in Canada.The Lac Hemlo ore body has an estimated reserve of 37 million tonnes at 6.2 g/t. The mining will take place at an initial rate of 3,000 t/d commencing in the first quarter of 1986. The mine and plant will be expanded to 6,000 t/d in 1988. At this capacity, Lac will be the largest producer in the Hemlo area.1. GEOLOGYThe orebody is divided into two (2) zones for mining purposes. The 'A' Zone is to the east and dips to the Northeast from surface to 300 m below surface. This zone has a strike length of 250 m to 300 m at an average width of 20 m. The upperpart of the zone will be mined by open pit and the remainder from underground. The 'B' Zone, to the north west of the 'A' Zone, although lined up is not necessarily an extension of 'A' Zone. 'B' Zone has a known strike length of 600 m and is open to depth and along the strike. It is over 70 m wide in the core. This zone holds most of the property's known reserves. 'C' Zone with narrow gold zones is under exploration in the south west portion of the property."

Jan 1, 1985

Electrochemistry Measurement, Using Chena Analyser, to Investigate Selective Separation of Pentlandite and Pyrrhotite

Sep 13, 2010

By B. M. Loftus

An investigation into the use of impinging stream (jet) reactors for the leaching of a free milling ore produced an increase in gold recovery by 10% while decreasing leaching time by up to 90%.Tests on refractory ores demonstrate no apparent improvement in recovery. However, leaching kinetics are dramatically increased when these ores are subjected to jet reaction prior to agitation.

Jan 1, 1997

TO THE. BOARD OF DIRECTORS AND MEMBERS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN Submitted herewith are the report of the Treasurer for the year 1945 and reports for the same year of the following committees: Membership, Admissions, Papers and Publications, Mining and Metallury (Magazine), and Library. In this review of the year by the Secretary reference frequently will be made to the "Paul" Committee and to the "hotter" Committee. The first is the special committee on Divisional Relationships and the second the special Committee on Ways and Means. These two important committees, appointed by President Harvey S. Mudd under authorization of the Board of Directors on March 21, 1945, were composed as follows:

Jan 1, 1946

By R. P. Mohring

Before we look at what the challenges and opportunities for future coal mining will be, it is appropriate to have a look at whether there will be a coal industry in the future. There is much talk about the damage caused by the burning of fossil fuels and the need to replace coal and oil with more environmentally friendly energy sources. Yes, there is evidence that the current practice in burning of fossil fuel has certain negative environmental effects, however, the adverse effects for global economic development from inappropriate measures to control greenhouse gas emissions would be severe.

Jan 1, 2001

By G B. Arehart

The Midas epithermal system is one of the larger low-sulfidation epithermal vein systems discovered in the western US in recent years, containing in excess of 3 Moz of gold (premining). The deposit is spatially and temporally related to bimodal volcanism in the Northern Nevada Rift; dates on igneous rocks (16 - 14.7 Ma) bracket the age of high grade veins (15.3 Ma). Hydrothermal alteration at Midas is typical of epithermal systems, comprising proximal potassic through distal propylitic assemblages; in contrast to many epithermal systems, Midas has minimal development of wallrock illite/sericite. Mineral assemblages are clearly zoned on the vein structures that acted as focal planes for fluid upflow. Geochemical zoning patterns also show this zoning. Metals were deposited in open-space veins as the result of boiling of hydrothermal fluids; multiple episodes of crustiform mineral deposition are documented in the vein textures. The major vein minerals include quartz, adularia, calcite, selenides and sulfides, with electrum as the primary ore mineral. REE patterns for vein material are similar to patterns for coeval rhyolites, but distinctly different from patterns of the host rocks. Stable isotope data are consistent with meteoric water as the dominant ore fluid. Combined REE and stable isotope data suggest that fluid from which the main ore-bearing stage of the veins was deposited was slightly lower pH than other stages.

Jan 1, 2005

By Lloyd R. Michels, Burke Cartwright, S. F. Ravitz

"INTRODUCTION Frequent attempts have be,made in the electrolysis of molten magnesium chloride to regenerate the electrolyte by allowing the chlorice generated at the anwdo to read with magnesium oxide and carbon within the melt according to the following reactions: (1) MgO + C + CL2 = MgCl2 + CO,(2) 2MgO + C + 2C12 = 2MgC12. + CO2.The principal advantages of such a procedure are that (1) the direct source of magnesium is magnesium oxide rather than the more expensive dehydrated magnesium chloride and (2) it is not necessary to handle or dispose of large quantities of chlorine or hydogen chloride.Grätzll 5/ proposed the use of an MgO carbon feed in a more or,less compact form in the anode compartment, of the cell. In a patent issued to Magall Aktiengecellschaft, 6/ a compact mixture of MgO and carbon is used as the anode itself. Kato 7/ and Backer 8/ add the feed in finely divided form to the surface of the anode compartment. The Bureau of Mines 2/ recently made a pilot-plant investigation of the electrolysis of suspension of MgO and carbon from chloride melts, in which it was found that although,current efficiencies of 60 to 70 percent were obtainable, the formation of sludges containing MgO, carbon, and magnesium seriously interfered with the operation of the cell,"

Apr 1, 1945

By Linfeng Zhou, Yuanbo Zhang, Rong Sun, Guanghui Li, Zhiwei Peng

The volatilization behavior of rhenium in the process of oxidative roasting of a molybdenite concentrate with 43.55 wt.% Mo and 321 g/t Re is explored based on identifying the relationship between volatilization of sulfur and rhenium. The results show that rhenium volatizes after sulfur and precise control of operating variables plays an important role in separating rhenium from molybdenite concentrate. When the roasting parameters are optimized as follows: roasting temperature 600 oC, roasting time 2 h, roasting atmosphere air, the volatilization rate of rhenium reaches 89.26%. In the process of solidification roasting, the volatilization rate of rhenium decreased almost to zero when the ratio of slaked lime/molybdenum concentrate was 10% excess to the stoichiometric requirement at 600 oC for 2 h.

Jan 1, 2016

By A. L. Crandell

History The Cortez Mining District has a long history of mining activity dating back to 1862. More recently, Cortez Gold Mines had operated a cyanide leach, counter current decantation (CCD) recovery gold mill from January 1969 to February 1976. This type of plant has been standard in the US for treating higher grade, finely disseminated gold in Carlin type ores. The mill was initially operated from 1969 to 1973 at 1.5 kt/d (1650 stpd) on oxidized ore from the Cortez ore body. In 1973, the mill was operated at 2 kt/d (2200 stpd) on softer, less oxidized, high clay ore from Gold Acres, located 13 km (8 miles) west of Cortez, NV. In February 1976, the oxidized portion of the ore body at Gold Acres was depleted and the mill ceased operations. Successful heap leaching of the lower grade portion of the ores was practiced at both Cortez and Gold Acres to supplement the milling operations. Valuable experience was gained in the operation of these two heap leaching programs (Duncan and Smolik, 1977). The ore heaps at Gold Acres and Cortez were releached with a limited crew from 1976 to 1979. The surge in the price of gold in late 1979 sparked an interest to incorporate new techniques into treating lower grade and less oxidized carbonaceous ores at Cortez. In early 1980, heap leaching was started on low grade oxidized dump material left from the earlier Cortez mining operation. By June of 1980, testwork was completed on the London Extension Dump, a low grade, mildly carbonaceous dump at Gold Acres. It was decided to convert the mill at Cortez from the conventional cyanide leach CCD recovery plant to a carbon-in-leach (CIL) recovery system. In May 1983, ore processing from the Horse Canyon deposit began. The Horse Canyon ore body contains both oxide and carbonaceous ores and is located 22.5 km (14 miles) from the Cortez mill. The Cortez CIL circuit was expanded to handle a blend of oxide and carbonaceous ores from Horse Canyon. Ore selection In the last quarter 1979, gold prices were increasing to a point where restarting the Cortez mill, idled since 1976, appeared imminent. Several previously explored geologic reserves at various stages of development were available as possible sources of feed for the mill. Initial metallurgical testing of dumps and tailings from earlier operations was completed, and previously uneconomic deposits were explored. It was decided to pursue sources of ore with the least lead time to production and those with the least capital cost requirements. A master plan was developed to bring the four profitable ore resources into production. The plan called for: • Heap leaching of waste dumps from the Cortez mining operation; • Restarting the mill to handle the waste dumps from the London

Jan 9, 1986

By P. A. Olubambi

The leaching of zinc and copper from Nigerian bulk sulphide ore with sulphuric acid in the presence of hydrogen peroxide was studied. The aim of the study was to investigate the effectiveness of hydrogen peroxide as an oxidant for the sulphuric acid leaching of zinc and copper from a complex sulphide ore. Distribution of elementals within the various particle sizes was initially determined by ICP-OES and XRF to provide a basis for explaining the dissolution process. The effects of concentration of hydrogen peroxide, particle size, stirring speed, and leaching time at a constant temperature of 298K were studied. There were variations in elemental and mineralogical composition within the different sizes. The concentrations of zinc and copper reduced as particle size decreased while silica, sulphur, iron and lead contents increased. Dissolution results showed that the leaching rate of copper was lower than that of zinc. The highest recoveries of zinc and copper were obtained at a leaching time of 180 minutes, stirring speed of 160 rpm, particle size of 75 µm and a concentration of 1M H2SO4/1MH2O2. It was observed that the leaching rate of zinc and copper increased with increasing hydrogen peroxide concentration. Increased stirring speed had a negative leaching effect as it promotes hydrogen peroxide decomposition. Keywords: Nigerian sulphide ore, zinc, copper, hydrometallurgy, sulphuric acid, hydrogen peroxide.

Jan 1, 2006

By James J. Graham

Uravan, Ambrosia Lake, Gas Hills and South Texas are all historic names in US uranium. These mining areas supplied the uranium that brought the United States into the nuclear age during the 1960s, and fueled the birth of nuclear energy for peaceful uses — a promise of nearly limitless, clean energy for the world’s future. That promise still exists today, but it is hard to hear over the rhetoric of environmental activists and politicians. Nuclear power offers dependable electricity with limited environmental impact at stable prices. Nuclear power releases no greenhouse gases or particulate matter into the atmosphere. High level nuclear waste (HLW), although long lived, is readily controlled and compact. In the United States, generating 1 billion kWh of electricity with coal produces 47 kt (52,000 st) of solid waste (ash and sludge), compared to 3.6 t (4 st) of HLW produced by nuclear.

Jan 1, 2002

Your assessment of the minerals business. The global mining industry is strong. I am convinced it will continue meeting the mineral needs of the world population for the foreseeable future. Two developments have greatly enhanced the industry’s ability to produce low-cost minerals. Technological innovations have resulted in increased productivity. And there has also been a dramatic expansion of the number of favorable countries in which to explore and mine. Capital expenditures have flowed to the low-production-cost mines and development projects as well as to the exploration projects and stable countries having the best potential for valuable mineral discoveries.

Jan 1, 2000

By Gordon M. Matheson, David K. Miller

Possible impacts to the water quality and production capacity of ground water supply wells by blasting is a common cause of complaints for blasting contractors, mining companies, and local regulatory authorities. The major complaints of changes in well water quality include; turbidity, discolored water (red, brown, black, yellow and milky water), and nitrate and/or coliform contamination. The major complaints for changes in well water production capacity include: loss of quantity production, air in water and/or water lines, damage to pump, and damage to well screen or borehole.

Jan 1, 1997

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldwell Counties in western Kentucky. According to the latest available statistics, this district supplied 1/5,960 short tons of fluorspar in 1937, compared with the total domestic production of 181,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds. The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldrell Counties in western Kentucky. According to the latest available statistics, this district supplied 165,960 short tons of fluorspar in 1937, compared with the total domestic production of 151,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By Michael A. Anuta

This report describes the potential for utilization of satellite observations for remote sensing of mine waste disposal areas. Four study sites consisting of metal and nonmetal mining areas in different climatic and physiographic regions of contigous United States were used in this investigation. The mine waste disposal sites consisted of mining of phosphates in Florida, copper in Arizona, silver in Idaho, and coal in West Virginia. Landsat satellite multispectral scanner observations were used together with aerial photographs, ground surveys, U.S. Geological Survey maps, and other ancillary information. Landsat digital data were categorized using automated supervised classification algorithms and an image analysis system. Detailed description of automated classification techniques employed and the accuracy attained is provided together with the results of manual interpretations. The inventory of areas distrubed for phosphate mining and a change detection investigation for-Polk County Florida were also undertaken during this study.

Jan 1, 1982