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By R. L. Virta

Four companies ? H.C. Spinks Clay Co., Inc., Imerys, Old Hickory Clay Co., and Unimin Corp. ? mined ball clay in four states in 2013. On the basis of preliminary data, production was 1 Mt (1.1 million st) with an estimated value of $47 million. Production increased by 3 percent in tonnage from 973 kt (1.1 million st) with a value of $45.1 million in 2012. Tennessee was the leading producer accounting for 64 percent of domestic production, followed by Texas, Mississippi and Kentucky. About 67 percent of total ball clay production was airfloat, 22 percent was crude or shredded and 11 percent was water-slurried.

Invensys’ recently introduced Field Device Manager for Foxboro I/A Series distributed control systems provides the industry’s first solution that takes advantage of both the latest Enhanced Electronic Device Description Language (Enhanced EDDL) and FDT technologies. This combination provides comprehensive lifecycle support to configure, calibrate, commission, diagnose and optimize the performance of any vendors’ foundation fieldbus device. The I/A Series Field Device Manager enables users to take advantage of any EDDL, Enhanced EDDL and/or FDT host deliverables supplied by the device vendor.

Jan 1, 2007

By D. H. Horswill

Red Dog, the world’s largest zinc mine, is located ninety miles north of the Arctic Circle in northwest Alaska on lands owned by the Inupiat Eskimo organization called NANA. NANA received a subsurface title over this resource as part of their settlement lands under the Alaska Native Claims Settlement Act and subsequently entered into a Lease Agreement with Cominco in 1982. Cominco, an international mining company focused on zinc, built and operated the mine. NANA’s principle objective in the development of the mine was to have it contribute to the development of sustainable communities within their traditional region. This meant creating job opportunities in a modern economy while preserving the traditional subsistence lifestyles. Preservation of their culture, language, and traditions are as important to the NANA people today as they were through ages past. The principles of sustainable development – matching economic, environmental, and social goals through continuous communications and high commitment to efficient and effective operations – have been core values for the Red Dog Mine from the beginning. This paper will describe how a large mining operation in a remote corner of the world has been able to contribute toward sustainable development in that region.

Jan 1, 2000

By John W. Shield

Oxide gold reserves are being rapidly depleted, especially in regions with long histories of gold mining, such as the Black Hills of South Dakota. However, these districts often have substantial additional deposits, where gold is refractory. It is not amenable to traditional cyanide extraction due to the presence of sulfide minerals that encapsulate or otherwise preclude the economic extraction of the gold. Several technologies have been developed to render refractory sulfide deposits amenable to traditional cyanide processing. These include roasting and pressure autoclaving. Unfortunately, these oxidation processes require substantial capital investment and incur significant operating costs. Microorganisms that obtain energy for their life processes by the oxidation of iron sulfides can be used to treat gold-bearing refractory sulfide minerals. As the bacteria convert the sulfide to sulfate, they expose any gold associated with the sulfide matrix. This makes the gold amenable to cyanide extraction.

Jan 1, 1996

By D. M. Jepsen

One of the first things we tell a potential new client is that they have only one chance to make a first impression with an Aboriginal community; all future communications and engagement will be predicated on that first impression. The key components of this most critical meeting are not your power point, your maps, or your draft plan for development ? they are instead a genuine, evident and clear demonstration of a sincere desire to develop a positive relationship that is based upon respect, and consideration and understanding of local communities and their interests, needs and desires. Relationship building is the foundation of proactive and positive consultation and accommodation with Aboriginal communities and the tone is set with the first meeting. C3 has refused more clients than we have accepted due most often to the fact that relationships between the company and the Aboriginal community have already devolved into a tense and toxic scenario. Land access and tenure certainty for exploration and mine development is critical to the foundation of a healthy, sustainable and environmentally and economically sound mineral exploration and mining sector. Without certainty confidence to invest in mineral exploration will be severely eroded. We all understand that substantive investments in exploration are required to increase the possibility of discovering, defining and developing new mines. The development of positive relationships based on a shared commitment of understanding, mutual respect and trust by Aboriginal Peoples and the mineral sector can provide the required business certainty and deliver social and economic benefits for local Aboriginal communities.

Jan 1, 2012

By Robin J. Hickson

El Abra has mining concessions granting the right to exploit minerals in more than 130 km2 (32,122 acres). SCM El Abra owns “rights to occupy” the surface of these claims. The company also owns the surface rights over the process plant area and over land conveyor route. The project has procured all material easements relating to the mine area, processing facilities and access rights of way. Engineering, procurement and construction Figure 1 sets out the development and construction schedule for the project. Development is already well under way. As of early January 1996, about 70% of the project was complete and more than 80% of the capital expenditures were committed.

Jan 1, 1996

By Pafos Busch, Martin Fischer, Johannes Jaeger

The Spitzenberg Tunnel is a 600 m (1,970 ft) long twin tube motorway tunnel on Germany’s Autobahn A44 between Kassel and Eisenach. Since flexibility was considered to be very important in the continuously changing geological conditions, NATM was chosen as the construction method. When passing an old quarry with only 1,80 m (6 ft) of overburden, the excavation works became extraordinarily challenging. This paper not only describes the special methods, like double sidewall drifts and pipe umbrellas applied in this zone but also highlights the cooperation between the parties involved, which in combination made the project a joint success.

Jun 13, 2021

By R. L. Zick

The High Density Sludge Process was originally developed by Bethlehem Steel Corporation for use on acid mine drainage and diluted waste pickle liquor discharges requiring continuous chemical treatment systems. This work began in the early 1970s and was first put into practical use around 1973. To date there are approximately 15 operating systems which have been installed on mine drainage in the United States, and another 10 systems worldwide. Dense Sludge is an innovative and improved method for treating acidic metal bearing streams in a manner which minimizes the volumetric generation of sludge for disposal. The technology utilizes a sludge recycle process which forms particles that have a low affinity for water, unlike conventional metal hydroxide solids which contain tightly bound interstitial waters. Typical acid mine drainage streams contain high sulfate concentrations which combine with calcium ions in lime based treatment systems to form gypsum crystals. The physical form of this gypsum is radically altered when the Dense Sludge process is utilized compared to the form generated in conventional lime treatment systems. The characteristics of the metals particles are also changed in this process, as the metal hydroxides are converted to metal oxides. Slides No. 1 and No.2 show scanning electron micrographs of conventional and densified sludges illustrating these differences. The magnification used was 300X. The dense sludge particles settle faster, dewater more readily, are more easily pumped, and hold much less water than conventional precipitates. In some cases, because the metal content of the sludge is more concentrated, it can be economically recovered.

Jan 1, 1998

By M. Adnan Göksel

Pyrite cinder is generated by roasting pyrite for sulfur dioxide production. It contains up to 62% iron, but also may contain other hazardous or toxic materials such as Zn, Pb, As, T1, Cd, Cu, Sn and S. Furthermore, the physical characteristics are not properly suited for conventional sintering. As a result pyrite cinder is considered to be unsuitable for iron and steelmaking or for outside storage because of its potential for causing environmental problems. In recent years industrialized nations have put increasing pressure on the manufacturers to either use such waste products or properly dispose of them. In this study, solutions to both the iron recovery and disposal problem were attempted by pelletizing the pyrite fines with internal carbon. The pellets, after hydrothermal hardening, were reduced and melted in a furnace for hot metal production. Hot metal of usuable quality was produced and the hazardous materials were either collected with the fumes or in the slag.

Jan 1, 1984

By J. Wickens

This paper discusses how Bald Mountain Mine dramatically reduced mercury production by treating process solutions with a liquid reagent called UNR 811A. The reagent is marketed by Cherokee Chemical Co., Inc. A summary of the bench tests comparing several different reagents is given. The ensuing plant trial is discussed and results are presented. The plant trial treatment costs are discussed. Finally, potential cost savings are discussed.

Jan 1, 2001

By M. E. Gershon

I would like to congratulate Professor Gershon on an idea that is obviously valuable and is certainly new to me. It has, however, to be further developed, in that one can get fallacious results by limiting oneself to positional weights. In the example problem, the positional weight of one block was 8.6 (the 8.0 value in the paper was incorrect) for 36 units in the cone, for a mean block value of 0.239. The positional weight of the second block was 4.4 for 15 units, for a mean block value of 0.293. Surely one would expect the second block to be rated higher. Additionally, the time value of money adjustment cannot be determined by depth, because the time that a block is mined is determined by the mining sequence, not depth. Figure 1 shows a slightly altered version of Professor Gershon’s pit. The overall value of the pit is the same, as are the total values under each of his blocks. The values in the right-hand cone have been reversed top to bottom, and the values in the rest of the pit adjusted to keep the central cone total unchanged. All values have been multiplied by 10. Figure 2 shows the sequence of mining, at three blocks per year, for Professor Gershon’s pit, and Fig. 3, the sequence for a pit under the other block. Table 1 shows the value and discounted value (157. ) of Professor Gershon’s pit, and Table 2 shows similar values for the second pit. It is apparent that the second pit schedule is more valuable than the first.

Jan 12, 1987

Contents

Jan 1, 1985

By V. Kecojevic

The objective of this research was to establish the relationship between production, consumption and energy cost in the surface mining of bituminous coal. Specific energy sources such as diesel, gasoline, electricity, explosives and bituminous coal were considered in this study. Gain in net energy, proportion of the cost of energy consumption and total energy cost relative to total revenue of extracted coal were determined, and a new energy efficiency index and a new energy-cost ratio were established. A case study on an operating surface coal mine was carried out to demonstrate the application of the newly developed method. The results of this study can be used by the mine operators in establishing strategies for the optimization of energy production and consumption, and for reducing the cost of bituminous coal extraction.

Jan 1, 2014

By Ben V. Petersen

Surveying is to tunneling, as a steering wheel is to a car—somewhat essential if you want to end up in the right place. The principles of tunnel surveying have remained unchanged since the first tunnels were constructed: To mathematically connect the selected start and end points of a tunnel and physically translate that alignment onto the ground. The alternative is just dead-reckoning and leaves the probably less than satisfying end results to chance. Today’s laser-guided tunnels often have to thread the needle through a maze of soil types, utilities, structural features and other underground considerations. Surveying makes it possible.

Jan 1, 2005

By Roger K. McLimans, Venkatramaiah N. Vasudev, Christian Knudsen, Stefan Bernstein, Dirk Frei

Computer Controlled Scanning Electron Microscopy (CCSEM) analyses of sediment samples from coastal regions of Kerala and Tamil Nadu states and the heavy mineral deposits of Chavara, South India, show large lateral differences in the titanium content in ilmenite due to varying degrees of iron leaching. As the depositional environments for the sands with varying degrees of ilmenite alteration are comparable, the cause for the different degree of alteration is due to differences in the primary source of the ilmenite or to differences in the geochemical history of the ilmenite grains during transport from source to deposit. The CCSEM analyses of the heavy mineral fractions show that source of sediments with a high content of titanium-enriched ilmenites, mainly the heavy mineral deposit around Chavara, resides in the khondalite belt of South India (granulite facies metasediments). The less titanium-enriched ilmenites are sourced from other rocks in the area such as the charnokites. Those conclusions are based on the high MgO content in the leached ilmenites, chemical composition of the accompanying garnets (low CaO and high MgO), and the concentration of aluminum-rich minerals in the sands.

Jan 1, 2005

By David Cronan

"Most of the recent renewed interest in manganese nodule mining has been focused in the Clarion-Clipperton Zone (CCZ) in the NE tropical Pacific where nodules are rich in Mn, Ni and Cu. However, equally interesting, but compositionally different, nodules occur in the tropical central South Pacific (CSP). The CC Zone deposits lie in the International Seabed Area whereas those in the South Pacific lie mainly in the Exclusive Economic Zones of Island States, principally the Cook Islands and Kiribati. The CSP nodules should not be regarded as an alternative resource to CCZ nodules, as they are enriched in different elements. Rather, the CCZ nodules should be thought of as a source of one group of metals (Mn, Ni and Cu) and the CSP nodules the source of another group (see below), mutually complementing each other and to be mined in parallel for their different metals.Manganese nodule mining in the South Pacific has been mooted since the 1970s. However, new data on manganese nodule composition and abundance there have recently appeared. Also, a recently developed interest in 'rare', 'green' and 'technology' elements has necessitated a re-examination of old South Pacific nodule data for information on these elements (previously thought to be economically unimportant), and the re-analysis of the deposits to obtain new data on them. Additionally, current and possibly future applications to the UN to extend island 'continental shelf' areas necessitates an appraisal of the manganese nodules in these areas. These developments have prompted recent work that has helped to refine our understanding of the distribution and abundance of metals of traditional interest in South Pacific nodules, namely Mn, Co, Ni and Cu, but has also drawn attention to other elements of possible economic interest including titanium (Ti), vanadium (V) and the rare earth elements (REE)."

Sep 1, 2014

By C. V. Deutsch, T. Acorn

Understanding and managing risk is of increasing concern for the mining industry. Although methods exist to model geologic uncertainty based on stochastic modeling techniques and multiple realizations, there are few approaches to manage this geologic uncertainty in pit optimization. Block values can be penalized if the block uncertainty is high, but the goal here is to consider the reserve risk within the pit. This paper presents an approach for pit optimization that considers all realizations simultaneously with a heuristic pit optimizer. The heuristic algorithm maximizes value and also penalizes reserve risk. The inclusion of multiple realizations provides access to the risk or uncertainty in the total pit value. Considering this information permits an active risk management approach that can manage the uncertainty in the reserves within the entire pit.

Jan 1, 2018

By L. Harris

The Yanacocha project is the first foreign investment in Peruvian mining since Cuajone during 1976. Three years after the project began, it has become the largest producer of gold from heap-leach operations in the world and the top producer in Latin America. The success of Minera Yanacocha SA (MYSA) opens a new chapter in Peruvian mining with the exploitation of its widely spread gold deposits. And it has attracted the interest of foreign investors in Peru’s mineral resources. Construction began on Aug. 1, 1992. The first gold bar was poured on Aug. 7, 1993 from ore from the Carachugo Mine. During 1993, Minera Yanacocha produced 2.5 t (81,000 oz) of gold and 9.4 t (304,000 oz) during1994 (40% above budget). Production was expected to exceed 15.5 t (500,000oz) during 1995 with the start-up the Maqui Maqui Mine.

Jan 1, 1996

By Valérie J. Bertrand, Richard W. Lawrence, Marcos G. Monroy

Two cemented paste backfill (CPB) formulations containing pyritic tailings were leached in deionized water in flooded and alternating air-flooded environments and in a simulated acid rock drainage-type (ARD) solution. Scanning Electron Microscopy (SEM), solid phase chemistry and acid-base accounting measurements documented the weathering characteristics of the CPB samples. Short-term exposures of the portland-CPB samples preferentially dissolved the cement binder to a greater extent than slag-Portland CPB mistures. In all cases, the added neutralizing potential provided to backfill by cement was short-lived and insufficient to neutralize the acid generating potential of the mixture.

Jan 1, 2000

By Kristian E. Waters, Hao Ma, Haibei Wang

Over the past few decades, ELM based separation processes have become an attractive and efficient way to remove toxic metal ions from the various aqueous waste effluent streams. This paper provides a comprehensive review of the generation, characterization, and applications of emulsion liquid membrane (ELM) from the more than 280 papers and books published so far. First, the ELM formation and the transport mechanism are introduced. Then the ELM stability and emulsion splitting methods are discussed in detail, followed by the latest research and findings of the extraction of copper and nickel using the ELM technique during the past few decades, including a thorough discussion of ELM operating parameters that impact ELM stability and extraction. In addition, the kinetics study and industrial application of this technique for the removal of coppers/nickel solutes are also presented and discussed.

Jan 6, 2023