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By A. C. Alexander

Chevron Resources Company owns and operates an open pit phosphate mine and mill 11 miles north of Vernal, Utah. The plant currently produces 500,000 tons per year of concentrate and has the capacity to produce 750,000 tons per year. The operation is currently being expanded to 1,300,000 tons per year of concen¬trate in order to supply a new fertilizer plant being constructed by Chevron Chemical Company in Rock Springs, Wyoming. A 10-inch, 96-mile pipeline is being built to transport the concentrate from Vernal to Rock Springs. The present and expanded operation will be discussed. HISTORY In 1915, Harry Ratliffe staked nearly 15,000 acres of low to medium grade phosphate rock along the southern flank of the Uintah Mountains. This deposit became the largest privately owned phosphate deposit containing approximately 700 million tons of reserves. Initial development of the deposit began in 1958 by San Francisco Chemical, a joint venture between Stauffer Chemical Company and Mountain Copper Limited. In 1968, Stauffer Chemical Company bought out Mountain Copper Limited and became sole owner and operator. In 1981, Chevron Resources Company bought the property from Stauffer and has operated the mining and milling operations since.

Jan 1, 1985

By José A. Matar Ibañez

Geologic terranes in Argentina include potential mineralized environments from localized younger Precambrian cratonic outcrops through Paleozoic sequences, generally in the northwest or under younger cover, to the Mes[o] zoic-Cenozoic Andean Systems in western and southern Argentina. Argentina is self sufficient or nearly so in many metallic, nonmetallic, and energy commodities, and exploration in each of these categories is ongoing. Present production of precious metals (silver and gold) is important, and many recent discoveries of base metals, precious metals, alloy metals, and other mineral categories have been made. Economic trends, geologic environments, and commodity types important in actual exploration are described, and it is emphasized that extensive areas showing attractive alteration, geochemical, and geological anomalies, especially of porphyry, cordilleran vein, and epithermal characteristics, remain to be fully evaluated.

Jan 1, 1986

By William J. Halvorsen

We are currently doing work on three ways to improve the performance of our froth flotation systems. One development is the use of a cationic flocculent added to the feed of the froth cells. This does give some improvement in ash of the product particularly in a situation where there is a good bit of clay present. Difficulty is usually experienced with clay carrying over with the water contained in the froth product and also adhering to the coal surfaces. Addition of the flocculent to the flotation feed preferentially flocculates the clay causing it to drop into the tails. The results of some laboratory test work on Pittsburgh 88 Seam coal in Eastern Ohio is shown in Table 1. [ ]

Jan 1, 1979

By Jeffrey Peterson, John Beesley, Martino Scialpi, John Cassidy

The DC Clean Rivers Project is DC Water's ongoing program to capture and treat combined sewer overflows (CSOs) during rainfall before they reach the District waterways. The Anacostia River system was designed to reduce CSOs into the Anacostia River and includes the Blue Plains Tunnel, Anacostia River Tunnel, First Street Tunnel, and Northeast Boundary Tunnel. A portion of the Anacostia River system was commissioned in March 2018 and the final component, the Northeast Boundary Tunnel, was placed in operation on September 15, 2023. This paper provides a summary of the experience gained during construction of this +$2.9 billion project, an overview of the system performance since its activation in 2018, and a look-ahead to the next phase of the DC Clean Rivers program: the Potomac River Tunnel.

Jun 23, 2024

By C. J. Im

As market conditions become more competitive, U.S. coal producers are faced with the increasing need to find methods of lowering production costs in their operations. One area worthy of investigation is the additional recovery of fine coal that is normally discarded in the preparation plant waste stream. United Coal Company is currently assessing the capability of the Deister Flotaire, a new application of a column flotation cell, to recover additional, saleable coal from preparation plant waste. This paper presents the technical data obtained to date. Work with a 0.76 m (30 inch) diameter cell installed in a plant shows considerable coal recovery is possible from a nominal 0.595 run (28 mesh) X 0 refuse stream.

Jan 1, 1986

By W. A. Zingg

Impervious zones in copper waste heaps create a problem in contacting the rock with leaching solutions. These zones are normally associated with compacted layers .formed on the surface of each lift by dump truck traffic and by disintegration of the rock exposed to atmospheric conditions. These layers are usually only a few feet in depth--but, nevertheless, act as barriers to vertical flow causing the leach solution to perch in the heap, Consequently, much of the rock remains untouched and the leach solution breaks out the side of the heap instead of continuing downward to bedrock. One solution to this problem is breaking the hard pans with explosive charges. However, to use explosives means adopting new explosive materials and methods. To use this process successfully requires finding answers to operating conditions inherent to waste heaps. Foremost among these are: (1) type and size of casing that can be used because of limitations brought about by drilling problems, caving and, corrosive conditions; (2) perforating the casing at required levels; (3) an explosive capable of being pumped; (4) obtaining detonation of the, main charges through, the wail of the casing; (5) an explosive with the ability to propagate through the voids of the rubble and one which is not affected by water, acidic solutions, or back pressure conditions from hydrostatic heads; (6) to heave and rupture the compacted zones without chambering or recompressing the waste material.

Jan 1, 1970

By P. J. Bethell

In the froth flotation process the detrimental effect of slimes on the froth flotability of valuable minerals has long been known.1 Work by Aplan2 on the froth flotation of coal has shown that the presence of clay slimes causes loss in flotation selectivity, and recovery of combustibles. Obviously then the presence of clay slimes to any great extent in the froth cell feed in a coal preparation plant is undesirable. This problem is exacerbated in plants treating raw 600 um (28#) by zero material due to the variation in flotation with size. The net effect of this phenomenon in a bank of cells treating raw minus 600 µm (28#) material s that by the time adequate flotation of the coarsest size fractions has occurred the finer sizes are already producing undesirable high ash material, which often leads to unacceptable overall quality. Reduction in aeration rate and/or chemical addition to combat this, further decreases the flotation rate of the coarsest fraction leading to heavy losses of coarse low ash coal to the tailings. The above mentioned characteristics formed a key aspect of the fine coal circuitry design at Elk Run Coal Company in Sylvester, WV. The plant was designed to produce compliance steam coal (less than 1.20 lbs. S02/million b.t.u.) Desliming ahead of the froth flotation was included, as the slimes in the plant feed were clay rich, had very high ash levels, and low potential recovery. Lab testwork had also shown that poor selectivity would be expected if raw minus 600 um (28#) material was froth floated.

Jan 1, 1986

By Walter C. Labys

This paper reports on recent modeling efforts to analyze the eastern U.S. steam coal market with a cross-sectional econometric as well as a quadratic programming approach. The background to coal modeling is examined first. The particular aspect of the steam coal market to be modeled are then presented and the corresponding coal model described. Both empirical results and rigorous mathematic pertubation analysis are presented. Conclusions are then drawn regarding potential modeling applications in the policy area.

Jan 1, 1979

By Philip G. Meikle

The Bureau of Mines Coal Mining Technology program has developed new concepts aimed at improving the efficiency of underground coal product ion. Conceptual designs have resulted in equipment prototypes, some of which are currently undergoing proof-of-concept evaluations at Bureau and cooperator facilities. Several of these systems and concepts are described.

Jan 1, 1984

By G. Montgomery

This is a summary of what has happened to the domestic production of two industrial minerals vital to a healthy US economy: fluorspar and barite. A few years ago we were self-sufficient in both minerals and good ore reserves still exist. FLUORSPAR Some 9% of the fluorspar presently being consumed in the US is imported, whereas the use of fluorspar has not declined proportionately. Several factors can be mentioned.

Jan 1, 1986

By Lloyd E. Haight

After accepting the invitation to make this appearance today, it occurred to me that the subject matter which had been assigned to me, namely, the purpose and role of an advisor, was, contrary to what; some people might think, a controversial subject. In my brief lifetime, I have discovered that the world is full of advisors; that is to say, there are many people who undertake to render advice concerning subject matters upon which they may, or may not be qualified to speak. It shall be my purpose today to set forth what now appears to be the function of the members of the Advisory Council to the U. S. Public Land Law Review Commission; and, in so doing, I hope that I do not offend the Commission or any other-member of the Advisory Council with whom I serve. It has always been my personal conception of the role of an advisor that he should tender advice when it is requested, and then only if he has prepared himself concerning the matter upon which the advice is being given. I am sure it was the Congressional intent at the time the Public Land Law Review Commission was established indeed it was the hope. of Congress--that those of us who were to become members of the Advisory Council were informed upon certain particular subjects and then at the proper time express our opinions upon these subjects-and, by the same token, not attempt to enter opinions upon problems with which we have no experience in theory or in actuality. Some wag once said that if Columbus had had an advisory council, he would still be waiting at the dock in Spain, and there is more truth than fiction in that statement. With this problem in mind, let us examine the purpose of the Advisory Council itself.

Jan 1, 1967

By P. R. Thomas

This paper addresses the relative long-term cost and resource position of new and existing ferrochromium production in selected Market Economy Countries (MEC'S). The market impact of new ferrochromium production in nations such as India and the Philippines and the continuing change in international trading patterns are also evaluated. This paper draws upon the data and analyses of a recent Bureau of Mines, Department of Interior, Minerals Availability Program appraisal that evaluated the cost and availability of chromite and ferrochromium production from the demonstrated resources of 80 producing or potential mining operations in 10 market economy countries.

Jan 1, 1984

By Michael M. Donahue

"The public interest -- as opposed to the narrow interests of particular shippers -- will also benefit from the establishment of adequate revenue levels and the revitalization of the railroads. And this is particularly true with respect to the transportation of coal. "

Jan 1, 1981

By Kevin Hegerle

The Henderson Mill has operated over a wide range of production rates, feed grades, manpower levels and recovery targets since start-up in 1976. Henderson Mill personnel, both management and hourly, have successfully responded to these changes by not only maintaining unit costs, but by actually decreasing unit costs. Methods of cost reduction have included conventional austerity programs, innovative technological improvements and creative work schedules. This paper addresses both maintenance and operating cost reductions and efficiency improvements.

Jan 1, 1986

By Fred H. Lightner

The feasibility evaluation of the Borealis project of Houston International Minerals Corporation (HIMCO) was initiated in October of 1980. The operation of the Borealis Mine and heap leaching plant began in late 1981. In order to achieve the rapid development schedule several items were necessary: 1) Pre-planning of environmental requirements and early study of key issues. 2) Adoption of conservative design criteria. 3) Coordination and cooperation between HIMCO and regulatory agencies. 4) Adoption of specialized engineering and construction procedures. 5) Careful evaluation of owner project management philosophy.

Jan 1, 1982

By A. Bruynesteyn

Results are presented from a series of tests designed to determine the beneficial effects of the microorganism Thiobacillus ferrooxidans upon the leaching of uranium from a pyritic uranium ore. Minus 1-inch (-25mm) 0.0711 percent uranium containing, pyritic ore from the Rio Algom Mine at Elliott Lake, Canada was leached with lixiviants of various Eh and pH as well as being subjected to a biologically-assisted ferric iron leach. In all cases, the biological leach gave superior extraction. At pH 1.6, the biological leach gave 100.6 percent extraction and the ferric iron leach 69.8 percent. This improvement in extraction is associated with a relatively rapid biological breakdown of the pyritic material, thus liberating uranium mineralization associated with these pyritic materials and regenerating the ferric sulphate lixiviant in situ.

Jan 1, 1981

By Lawrence E. Mannion

In southwest Wyoming lies buried the world's largest source of natural sodium carbonate, or soda ash. Perhaps a hundred billion tons of trona (sodium sesquicarbonate) are contained in ancient lake beds in the Green River basin'). There the Green River Formation encloses more than 40 extensive beds of trona. At least 25 of these exceed 3 feet (1 meter) in thickness and most of them are more than 300 square miles in extent. Five have been exposed in mines and lie between 800 and 1500 feet below the surface. Others lie at depths of from 400 to 3500 feet. Three companies have underground mines that supply trona to adjacent soda ash plants. These are the FMC Corporation, Allied Chemical Corporation, and Stauffer Chemical Company. A fourth, Texasgulf Corporation, has a mine under development. In 1974, annual soda ash capacity in the Green River area was approximately 4,300,000 tons, which requires the mining of about 7,500,000 tons of trona.

Jan 1, 1975

By Manuel Viveros J.

This paper will deal with the type of rocks so called evaporites, which are sedimentary rocks produced by water evaporation from seas, lakes or marginal lagoons, in warm and arid climates. Salts derived from these deposits are precipitated according to their solubility; that is, the more soluble precipitates first, overlain by other sediments like silts, shales, limestones, sands, etc. The most common evaporites, according to their chemical composition, are : Chlorides Sulphates Carbonates Nitrates Borates Common salt, or halite, sulphates like anhydrite and gypsum, are the most important. Potassium chloride (silvite and carnalite) and potassium sulphate are of great commercial value.

Jan 1, 1974

By Walter E. Heinrichs

Early history of the district is typical of many, particularly in Southwestern United States. The usual early Spanish influence was felt; Marcos de Niza, Coronado and Father Kino are most notable, but authentic records regarding Spanish mining activities are sparse. About 1769 the Indian village of Tucson became a Spanish settlement. During the next century prospecting attempts were largely interrupted by the Indian, Mexican and Civil Wars. By 1870 Tucson had a population of 3200 and by 1880 the Southern Pacific Railroad extended all the way from Los Angeles. Pyrometasomatic copper ore was first produced with some local direct ore smelting done during the late 1800s. By 1907, a rail line was built from the Twin Buttes mines to Tucson by the Twin Buttes Mining and Smelting Company. World War I was a very active period, with mixed copper, lead, zinc, gold and silver production. This came mainly from underground replacement and contact metamorphic deposits and from practically all portions of the district. Some of these operations continued intermittently until the 1929 depression.

Jan 1, 1976