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By David Chastka, Isidro Rivera, Shawna Von Stockhausen, Idit Zarchi

The City of Santa Cruz Water Department is replacing the existing Newell Creek Dam inlet/outlet works at Loch Lomond Reservoir in the San Lorenzo Valley. The project will improve the City’s overall operational efficiency, improve system performance, and improve the safety and reliability of storage for the City’s drinking water supply. The project comprises new inlet works* (three new inlets that control and convey flows into and out of the reservoir, and an intake control building), an inlet/outlet tunnel with a 48-inch conduit to convey flows into and out of the reservoir, and a new outlet structure at the toe of the dam. The outlet structure includes a release point for energy dissipation of emergency drawdown flows, a connection to Newell Creek Pipeline, and beneficial releases into Newell Creek. The project also includes a new dam seepage collection and monitoring system and appurtenant structures such as a culvert bridge over the spillway plunge pool to improve access to the new outlet. Notable complex project components include in-water work to connect the new intake shaft pipes to the three new inlets. The project includes one major milestone with a work window regulated by environmental permits that could only be amended/ extended with approvals from those agencies. If not met, the milestone work would have caused significant delays (potentially up to one year) to the project.

Jun 13, 2021

By J. Leonard Frame

A coal-fired fluidized bed combustion (FBC) system will be installed at the Owatonna Tool Company, Owatonna, Minnesota. Two FBC combustors will burn solid fuels: coal, petroleum coke, and wood and paper wastes. Crushed dolomitic limestone will be used to control sulfur emissions to EPA limits. The combustors will supply indirectly heated hot air and hot water for paint drying operations, washing processes, and space heating. The program is sponsored by the United States Department of Energy and the Owatonna Tool Company, and is one of five programs designed to demonstrate industrial applications of coal-fired fluidized bed equipment. The paper will describe the combustion system and the results of development tests with dolomitic limestone for sulfur emission control.

Jan 1, 1978

By L. F. Zeiler

In the past, health concerns in coal mines have primarily centered on those elements which have been essentially inherent to the mining environment. These would include respirable coal mine dust, respirable crystalline silica, excessive noise levels, and diesel exhaust particulates. Commercially-available chemical products are prevalent on mine property. These potentially toxic materials are chemical formulations that can degrease, clean, and lubricate metal parts, separate coal from rock in float/sink operations, and aid in roof consolidation, among other uses. As the general public has become more aware of the hazards of chemical exposures, miners have likewise become more concerned about working with an ever-expanding variety of chemical products on the job. Often, product or chemical specific hazard communication training is inadequate or ineffective, and miners do not know exactly what the ingredients are in the products they handle, or the health hazards involved with their use or misuse. Currently, the Mine Safety and Health Administration (MSHA), by law, enforces 1972 Threshold Limit Values (TLV). MSHA is making preparations to adopt new personal exposure limits for enforcement. The values given throughout the article are 1994 TLV's and are not enforcement standards, but are used for discussion purposes. They reflect the current scientific thinking regarding personal exposure to these chemical agents. An overview of these products is presented, and the potential health hazards associated with their use are discussed. Controls needed to prevent overexposures, such as proper handling procedures and personal protective equipment, are covered. Methods used to collect and identify contaminants are presented.

Jan 1, 1995

By D. C. Lynch

While silica ores are generally considered to have little value, those with exceptionally low B and P content have, potentially, significant worth if processed for use in photovoltaics. The sales value of a cubic meter of ?run of the mill? silica sand is $42 per cubic meter (retail and delivered). If the silica sand can be used to produce solar silicon, its value after processing is $34,000 per cubic meter. Factors that impact the suitability of silica for direct processing in production of photovoltaics are examined.

Jan 1, 2010

By John S. Owens

The National Steel Pellet Project and the Butler Taconite Project are operated by The Hanna Mining Company in the vicinity of the towns of Keewatin and Nashwauk, on the western Mesabi Range. Production began in 1967, after seven years of exploratory and development diamond drilling and reconnaissance magnetic surveys, Previously, direct shipping hematitegoethite ores and gravity concentrates had been produced in the area from numerous open pits and several underground mines since the start of the century. Total shipments of these oxidized ores amounted to more than 200 million tons, but at the present time such reserves are nearly exhausted, and there are no mining operations in the Keewatin-Nashwauk area except at the two taconite projects. The locations of all of the present taconite operations on the Mesabi Range are shown in Figure 1, extending for a distance of about seventy miles from the Butler plant to the Dunka River area. The Butler and National plants have a combined rated capacity of 4.4 million tons of pellets. Their reserves cover a combined strike length of about eight miles on the Biwabik iron formation. All of the intervals between present taconite operations on the Mesabi are potential sources of additional magnetic taconite; in particular, exploration and economic studies have been carried out by Jones and Laughlin Steel Corporation in the Biwabik area between Aurora and Virginia, and by Pickands Mather and Company in the Hibbing area. However, west of the Henna and Butler holdings, it appears unlikely that magnetic taconite exists in commerical quantities at economic depths due to extensive oxidation of magnetite to hematite.

Jan 1, 1968

By R. L. Keiski, H. Miettunen

"The serpentinite massifs of Hitura are located in the municipality of Nivala in Central Finland. The most important sulfide minerals in the ore are pentlandite, pyrrhotite and chalcopyrite. The ore body consists of amphibolite rocks in contact with serpentinite against mica gneiss. The mean Ni grade of the ore is about 0.7%, and the highest Ni grades have been encountered in close contact. In general, the inner parts of the ore are strongly serpentinized ultramafite and some sulfides have been converted to mackinawite and valleriite. The degree of alteration varies considerably within the ore body and, correspondingly, the grain size of the sulfides varies as well. In this study, flotation tests were done with samples from different zones of the ore body. The flotation test results on the bench scale and plant scale are discussed in terms of the mineralogical features of the ore. Ores in the North Hitura zone differ from those in the South Hitura zone.IntroductionThe Hitura nickel mine, like the entire Nivala area, is part of the Bothnian Svecokarelian schist zone, where numerous Ni-Cu boulders have been discovered since the early 1930s. The Nivala area has therefore been the subject of exploration activities by the Geological Survey of Finland (GSF) and mining companies. The first period of exploration started in 1936, and the Makola nickel deposit, located 3 km south of the Hitura mine, was discovered by GSF in 1937. About 415,000 tonnes of ore were mined at Makola between 1941 and 1954. In 1937, during the exploration and development stage of the Makola mine, boulder tracing and a geophysical survey revealed a significant ultramafic body with some lowgrade Ni-Cu occurrences in the South Hitura zone.In 1961, GSF continued the exploration program in the area and discovered the North Hitura ultramafic complex and its allied Ni-Cu occurrences. In 1964, Outokumpu Oy bought the property and, after underground exploration, comprehensive mineralogical studies, process research and a feasibility study, production started in 1970 (Isohanni et al., 1985)."

Jan 1, 2015

By J. Larsson

In the pursuit of increased safety the mining industry has worked to develop systems for remote control and autonomous operation of both stationary and mobile equipment. This paper reports on a newly developed system for teleoperation and autonomous tramming of LHD (Load-Haul-Dump) mining vehicles that not only increases the safety of the operators, but also has the potential to increase productivity.

Jan 1, 2010

By Charles T. Holland

INTRODUCTION Insofar as I am aware, the term rock mechanics was not in the English dictionary in 1930 when I started my graduate program at West Virginia University. Hence, I never thought that I was undertaking studies in rock mechanics when I undertook to write a thesis on the physical properties of West Virginia coal. In this case, the subject was primarily concerned with the compressive strength of coal, the elasticity of the coal, the physical weathering properties of the coal and its friability. These days investigations of rocks pertaining to such properties are included in the term "rock mechanics". Other than this aspect, the principle interest in this part of my program was that I became interested in the strength of coal from the standpoint of structural purposes, and also became cognizant of its elastic properties as well as its energy storing properties. This research also tied in with a remark that Professor Lawall made in a Mining Methods class in 1928 when he remarked that a peculiar thing was happening in the southern part of West Virginia, namely, in the Pocahontas coal field. His remarks were to the effect that pillars were blowing up in the mines and when asked why he replied the cause was not known. The failure of three-inch coal specimens, especially those in stronger coal, in non-hydraulic actuated testing machines was reminiscent of his description of those pillar bursts or bumps.

Jan 1, 1971

By Toby Mayo, Tassos Grammatikopoulos, Massoud Aghamirian, MARK FEDIKOW

The Zoro pegmatite project in east-central Manitoba occurs 20 km east of the historic mining town of Snow Lake. A composite sample (Master Comp) was prepared fromthree pegmatite zones within Zoro Dyke “D1” including the North, Central, and South Zones for mineralogical analysis and heavy liquid separation (HLS). The mineralogical examination was conducted on a subsample crushed to ca. P80 of 600 μm to determine the overall mineral assemblage, liberation of spodumene, and assess the potential recovery of spodumene by flotation. XRD and QEMSCAN results show that the sample consists of spodumene (10.5%), quartz (29.3%), plagioclase (29.0%), K-feldspars (21.3%), micas (5.1%), tourmaline (2.9%), and Fe-Mn-phosphates (0.1%). Spodumene is well liberated (88%), but also forms complex particles (7%), and middlings with quartz (4%). Liberation of spodumene increases from 81 in the + 600 μm to 95%in the − 106 μm size fraction. Liberation of quartz, feldspars, and micas account for 89%, 94%, and 83%, respectively. Electron probe micro-analyses and LA-ICP-MS showed that the average Li concentration is 3.7% in spodumene, 2196 ppm in micas, 1001 ppm in tourmaline, and 115 ppm in K-feldspars. Thus, spodumene accounts for 96%, micas 2%, Fe-Mn phosphates 1%, and both K-feldspars and tourmaline for < 1% of the total Li in the sample. The mineralogical data indicate the potential to recover spodumene by flotation with minimal Li losses due to other than spodumene carriers. Heavy liquid separation was conducted on the Master Comp which was crushed to − 6.4 mm, while the − 600 μmfractionwas removed fromthis test. The coarse fraction − 6.4mm/+ 600 μmwas subjected to HLS tests with eight heavy liquid-specific gravity cut-points (2.65 to 3.10 g/cm3). HLS indicates that it is possible to produce a high-grade lithium concentrate (close to 6% Li2O) after the rejection of iron silicates with magnetic separation.

Sep 16, 2020

By George I. Staber

This paper is a brief review of the recent history, and the present status of, of the program designed to develop practical new processes for producing pipeline quality gas from coal. Clean synthetic pipeline-quality gas from coal became a major objective during 1971. Agreement was reached with the American Gas Association, Inc., to cosponsor a $120 million, 4-year program to be funded $80 million by Government and $40 million by American Gas Association. The program was first announced by President Nixon in his Energy Message on June 4, 1971, and a portion of the additional funds needed for the program was approved by the Congress in the December 1971 supplemental budget action. A natural gas shortage has developed in the United States and every indication is that it will worsen. Many transmission and distribution companies have already been forced to curtail sales because of the shortage. Large sums are being committed to systems needed to bring liquefied natural gas from abroad and to plants to manufacture synthetic natural gas from petroleum--also largely imported. On the other hand, there is sufficient domestic coal to supply all of the needed gas through the next century. This accelerated program is designed to provide processes for making gas from coal at costs, including security costs, below the imported alternates. As outlined in the President&apos;s Energy Message, OCR and A.G.A. have accelerated the coal gasification program to make it possible to construct and operate a "demonstration plant" (semicommercial size) after 1975. Several processes, in various stages of development as will be described later, are being supported. Concurrently, the overall program will be constantly monitored and evaluated with the assistance of an independent, unbiased contractor. C F Braun of Alhambra, California, was selected for this task and has been actively engaged in it for the last several months. Through continuing studies of the various processes and subprocesses as the pilot plant program continues, optimums will be discerned. These will serve as

Jan 1, 1972

By J. B. Hiskey

Thiourea is a reagent capable of complexing gold and silver. With the proper oxidant, thiourea can effectively dissolve metallic gold and silver. A thiourea leaching system possesses potential advantages over conventional cyanidation including acidic solutions instead of alkaline, cationic complexes in contrast to metal-cyanide anionic complexes, and faster leaching rates with acidic solution of thiourea. Generally, the rate of metal dissolution in thiourea solutions is fastest when ferric ion is employed as an oxidant. Acidic thiourea solutions for certain applications could offer a nontoxic and noncorrosive option for processing gold and silver. This paper provides information regarding the fundamental chemistry of the acidic thiourea system, and reviews the dissolution of both silver and gold in acidic solutions of thiourea. The recovery of gold and silver from acidic thiourea solution is discussed.

Jan 1, 1981

By Robert L. Stroup

Let me open my remarks this morning by stating how we as legislators and as natives of the western coal-producing states feel about our role in becoming one of the major producers of coal-related energy and chemical products is similar to the groom at his shotgun wedding. We are apprehensive, to say the least, as to the ultimate outcome. We do not have complete freedom of choice. It will certainly change our quality of life. We are concerned about the increase in population, but are realistic enough to recognize that we are forced to go through with the marriage. Other alternatives could be worse than the bride. Also, we were aware that this could occur, but we did not plan on it being this sudden. Or, put another way, we have two groups advising us that our choices are cattle or coal, food or fuel, pollution and people or pure air, wheat or gas, clean water or prosperity, noise or solitude.

Jan 1, 1976

By Chris Roos

The mining industry has made strides in planning for operations to be safe for the workforce and public, to protect the natural environment, and to maximize value for shareholders. However, many of the techniques used to accomplish these goals are based on estimated models of mineral content, production efficiency, and economic performance. The industry has begun to recognize the need for understanding the uncertainty in these models, how it affects their decisions, and what the potential impacts are for each project. The challenge has become how technical professionals can effectively communicate the impact of this uncertainty and its importance to both technical and non-technical audiences. This paper presents mining engineers (and other technical professionals) with traditional and modern principles of data visualization and technical communication that can assist with communicating the effects of uncertainty in the mine planning process.

Jun 25, 2023

By O. V. Bush

Most governments recognize that energy efficiency represents a partial solution to reducing global capital shortages and environmental crises that threaten to seriously impede economic growth. Much of the United States and many foreign countries are embracing the concept of Integrated Resource Planning (IRP) which incorporates Supply Side Management (SSM) and Demand Side Management (DSM). Since SSM comes at twice to three times the cost of DSM, it makes economic sense to employ the energy conservation techniques of DSM. This paper will explain these concepts and some of the incentives being put forward by governments and utilities to promote DSM.

Jan 1, 1995

By Ali Hafiz, Rich McCafferty, Chris Blanchard, Kaz Tabrizi, Kevin Ruston, Joseph Rigney, Mike Keville, James Dorta

Many existing tunnels have deteriorated as they age, requiring a massive amount of investment for their rehabilitation. The tunnel of interest in this paper is being rehabilitated by adding precast concrete arch panels under the existing concrete ceiling, and measuring the gap between them was the objective of this research. For this purpose, a mobile 3D laser/thermal scanner was used for scanning the tunnel, especially for the purpose of measuring its profile. To calculate the gap, the distance between the tunnel profile and the theoretical profile of the concrete arches was measured. Additionally, an in-house program was developed using MATLAB to automate the data processing to determine the above-referenced gaps. Results were provided in the form of heat maps showing the measured gap.

Jun 23, 2024

By John C. Brower

The purpose of this paper is to examine the Gays in which- the policies of the U.S. government, mining companies and third world countries affect each other with regard to the availability of minerals. The interaction involves U.S. policy towards the mining industry, the policies of the companies themselves, and the policies of third world countries towards the U.S. and multinational companies. It is assumed in this discussion that U.S. policy will continue to be to seek certain minerals from abroad rather than attempt to develop domestic sources for all its requirements. This would seem to make sense both from the standpoint of cost, and for preserving what domestic resources there are so as to maintain some degree of market leverage. In today&apos;s jargon, this means greater dependency on the "third world", which, for this discussion, includes virtually all the nations in Africa, South America and Asia. Concern for availability raises the important distinction between dependency and vulnerability, and as the Director of the Bureau of Mines has pointed out, the two are not the same. Dependency is not neccessarily a bad thing; it is vulnerability that counts (Norman, 1980)

Jan 1, 1982

By Todd Hollingsworth

The Boddington gold mine is located near Perth in Western Australia in the Saddleback Greenstone Belt, a fault-bounded sliver of Archaean volcanic and shallow level intrusive rocks, surrounded by granitic and gneissic rocks. The mine began operations in 1987, producing about 7.7 t/a (250,000 oz/year) until mining ceased in 2001. Built on the footprint of the original mine, the Boddington gold mine expansion project involved opencut mining from two large pits. Expected gold production is around 31 t/a (1 million oz/year) for the first five years. It will be the largest gold mine in Australia. The mine has proven and probable reserves of more than 622 kt (20 million oz) of gold and has an expected life of more than 24 years. The mine is currently solely owned by Newmont Gold Corp., the world?s second-largest gold mining company, employing around 28,000 people worldwide. The conveyor and belt feeder contract for the Boddington gold mine expansion project was awarded by Aker Kvaerner Clough Murray Roberts (AKCMR) to FLSmidth Conveyor Engineering Inc. in August 2006. The contract involved the design and manufacture of 15 conveyors and 17 belt feeders with belt widths ranging from 450 mm to 2.4 m (18 in. to 96 in.) and conveyor lengths from 16 m to 2,172 m (52 ft to 7,125 ft). The total motor power added up to more than 16,700 kW (22,400 hp). The total length of all belting was almost 11.5 km (7.1 miles), and the total fabricated steel weight was approximately 3.7 kt (4,100 st).

Jan 1, 2010

By G. Reed Marchant

During the past two decades, we have witnessed the computer revolution. Like other revolutions, it has been successful in many ways; however, it has not been without difficulties. One of the areas where these difficulties have been more prevalent has been in the application of computers for the purpose of controlling industrial processes. During the early 1960&apos;s, many people naively assumed that bridging the gap between data processing and process control was a simple matter of connecting a few wires, doing a little programming, laying off most of the people and watching the plant make great increases in production as the lights on the computer blinked on and off. Unfortunately, it has not been that simple. Instead, a whole new-set of disciplines has been required to overcome the major obstacles that exist. Nevertheless, current successes are proving that the digital process control computer is here to stay, and that through the application of digital computers an attractive return on investment can be obtained in many applications.. The purpose of this paper is to illustrate some of the requirements for successful implementation of computer control systems, with particular attention to the following four objectives: First: Acquaint the reader with the general control problems so that he may more fully recognize the major requirements for successful implementation. Second: To acquaint the reader with the types of control hardware that can be considered for use in the development of control systems. Third: To discuss some of the major obstacles that must be overcome for successful implementation of computer control systems. Fourth: To discuss the systems approach in the development of control systems and to illustrate it in the implementation of an actual control system.

Jan 1, 1971

By Lynn B. Hales

Unfortunately, the term "control" has a negative connotation in the minds of many of our operating plant personnel. Whereas the opposite is true of those associated with research and technical centers in our industry. The magnitude of this difference in opinion and actual experience has often proved to be a major factor influencing the success or failure of process control applications. Through the years, many plant people have endured a number of unsuccessful attempts by "outside" people to "optimize" their plants; and these experiences have proved to have had quite a callousing effect on them. On the other hand, in many plants, successful process control efforts have made firm allies of the operating personnel, and have increased the number of metallurgical people who are well qualified and experienced in process control. The instrumentation industry, computer industry, and the mining industry&apos;s ability to quantify what is really happening in our processes have grown and developed rapidly since the first control efforts were made in the 1930&apos;s (1). Because of this-,: new control opportunities are becoming increasingly more feasible and older well established ones are becoming even more practical and necessary with regard to the economic s of our industry.

Jan 1, 1979

By G. France

The Blair Athol Coal Mine (BAC) is a large open cut operation in the Bowen Basin of Queensland, Australia. Current mine capacity is about 11 million tonnes per annum (Mtpa) of export coal. On-line analysis at BAC consists of two Coalscan 9500s installed directly on the output of the crusher plant and immediately before the product stockpiles, while a third Coalscan 9500 is installed on the transfer conveyor feeding the train loading bin. The two product Coals cans have a dual purpose. The first is to provide real time coal quality data directly back to the mining operations. The second is that of modeling the product stockpile with accurate on-line information. This modeling enables both production and coal quality personnel to accurately examine the coal quality of each stockpile with a degree of resolution which previously had never been achieved.

Jan 1, 1999