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By J. Herbst, J. A. Kitchner, J. P. Anfruns, G. Poling

Measurements have been made of the rate of capture of single particles of strongly hydrophobic, surface-methylated, quartz, of sizes ranging from 12 to 40 pm diam., by single rising bubbles of diam. 0.5 to 1.1 mm. The results agree closely with the theoretically calculated hydrodynamic collision rates, indicating that, in this system, every collision results in capture and retention of a particle.

Jan 1, 1976

By Clarence O. Babcock

A simple robust rock bolt load gage was tested in the laboratory to define its characteristic behavior and to obtain a measure of its performance. The gage uses three vibrating wire sensors crimped 120 degrees apart into the outer surface of a hollow cylindrical steel tube. The resonant frequencies of the wires change as the gage is loaded. This change is read with a Creare meter developed for the Bureau on a previous contract to read borehole stress gage results. A statistical analysis of data obtained defines the variables influencing results. A U. S. patent (3,914,992) assigned by the author to the Department of the Interior was granted October 28, 1975.

Jan 1, 1976

By G. Wayne Clough

During shallow tunneling in an urban environment, deposits or pockets of saturated soil or fractured, weathered rock are often encountered. Under such conditions, special problems with tunnel support, underpinning of structures adjacent to the tunneling, and/or flow of groundwater into the tunnel occur. If the ground conditions are appropriate, i.e., the soil is sandy, silty or fissured, or the rock is weathered or fractured, the solution to these tunneling problems may be chemical stabilization of the ground. Injection stabilization as an aid to tunneling is practiced extensively in Europe and its use is increasing in the U.S. The advantages of this technique over conventional solutions can be substantial in terms of cost and time, especially in mechanized tunnel boring where even a small zone of soft ground can bring the tunneling to a complete halt. In this paper European practice in using chemical ground stabilization for urban tunneling will be reviewed. In contrast to previous papers which have dealt with specific applications (1,5,8,9) this paper will broadly cover the subject, addressing itself to grouting techniques, costs, the reasons for grouting, philosophy of the users towards grouting, design of grouting solutions (or lack thereof) and methods of quality control. Differences with U.S. grouting practice are also noted. The information presented is derived from several visits to Europe, discussions with European and U.S. grouting personnel, and the available literature (2). The author's most recent European trip was made under the auspices of the U.S. Department of Transportation in conjunction with a research study being performed at Stanford University; a detailed report of this visit is available in reference (6).

Jan 1, 1976

I met Austin Taylor in Vancouver on my way home from my first Pioneer examination. He asked me to examine the unsuccessful old Lorne mine, adjoining and west of the Pioneer. I had no idea that this meeting would lead to one of the outstanding successes and pleasant associations of my career. I knew nothing of Taylor, except that Gen. McRae and associates said that he had been engaged in lumbering and was interested in an oil and gasoline marketing company called Home Oil. But even if the Lorne examination would be only a small one, in the depths of the Depression in 1931, I was glad to have a chance to look at another gold property, so I agreed to visit the Lorne early in August. The start of the trip was not auspicious. I had been working hard on an unproductive study, and was greatly worried by my father's hopeless illness with tuberculosis. To get a little rest on my way north I had arranged to go from Seattle to Vancouver on the night boat that connected with my train. To my surprise, Bill Boultbee, an associate of Taylor, met me at the train in Seattle at 9:30. He said he would drive me to Vancouver, arriving at one In the morning. I was so tired that I begged off and let him take the drive alone Boultbee was most understanding and friendly, but I knew how I would have felt if I had been kind enough to take the long drive to help a stranger and then had been forced to make the return midnight drive alone. I was lucky they did not call off the examination at once. I got a good sleep on the Vancouver boat and Austin Taylor met me at the Hotel Vancouver for breakfast. After a brief talk he took me to the small steamer that made the 4-hr sail up Howe Sound to the village of Squamish. This was the end of the Province-owned Pacific Great Eastern Railway that was eventually to be a shortcut from Vancouver to the Canadian National main line at Prince George. Because

Jan 1, 1976

By David G. Chedgy

The Meadow River No. 1 Preparation Plant, owned by Sewell Coal Company, a subsidiary of the Pittston Company, was commissioned in the spring of 1974. The plant is designed to process 400 TPH of 5" x 0 raw coal. The 5" x 114'l fraction is processed in a Heavy Medium Vessel with the 114 x 28M reporting to Deister Tables for cleaning. The 28M x 0 fraction is cleaned in flotation cells, with the froth going to clean coal vacuum filters and the tailings to a static thickener where the underflow is reclaimed on Refuse Filters prior to disposal. The noise dosage a worker receives is determined by the ratio of the length of time the worker spends in a particular noise environment divided by the noise exposure in that particular environment. If the worker is exposed to several different sound levels, his total dosage would be the sum of each of the individual dosages. The equation for determining the dosage is: [ ]

Jan 1, 1976

I reached New York at the start of my second South American adventure on Jan. 9, 1916. In the Anaconda office I found that we were not to take the steamer for two weeks which gave me time to study reports on Potrerillos and Corocoro. Reno Sales, whom I had met in Butte only casually, was to go with us to South America. Though he was only a little older than I, he was already an unquestioned leader of our profession, and we became and remained good friends. William Braden was in New York and would return to Santiago with us. Tom Hamilton would also be returning from a vacation. Leighton Stewart, a young engineer who was to work for Braden, was going on the steamer with us, taking along his wife. And of course Dr. Ricketts would go along. He had just become engaged to John Greenway's half sister, Kate Greenway, and in order not to be away from her longer than was necessary, he did not reach New York until a day before we sailed. This made eight of us who would be in the party. We were to go to Corocoro first, as Braden had taken an option on the Chilean company there. Development was already under way. As reports came in by mail we tried to get as good an idea of the property as we could before the actual examination. Mr. Thayer "put us up" at India House, one of the best lunch clubs in New York, and Reno and I ate our lunches there almost every day. Thayer, Braden, and Cornelius Kelley, who was to succeed Mr. Ryan as president of Anaconda, joined us when they could. At the lunches they told us about the under- ground war in Butte a few years earlier. When I wrote my chapter on the Butte wars in Romantic Copper more than 15 years later I could not help being biased a bit by my friends, all of whom were on the Anaconda side. But their opponents in the Clark and Heinze camp were just as biased in their comments on my book.

Jan 1, 1976

By C. G. Janes, N. Finkelstein, L. M. Jr. Johnson

In May, 1966, the General Services Administration (GSA) announced a program to encourage additional domestic production of copper in the interest of national security. Upon learning of the copper production expansion program, Duval Corporation entered into negotiations with GSA for development of the Sierrita copper-molybdenum property under the program. Agreements between the GSA and Duval Sierrita Corporation, a wholly owned subsidiary of Duval Corporation, were concluded in 1967, with the Sierrita Concentrator beginning operation in 1970 at a designed capacity of 72,000 STPD. Subsequent additions and modifications have expanded capacity to 90,000 STPD. This property, located approximately 20 miles south of Tucson, Arizona, represents an investment including working capital of about $200 million. These funds were provided from an $83 million loan from GSA, repayable in copper valued at 38 cents per pound, $48.75 million of bank loans subject to U. S. Government V- loan guarantees, and Company capital contributions. Current general operating statistics for the concentrator are listed below: Ore Grade 0.32% Cu., 0.030% Mo. Daily Tons Milled 90,000 STPD Annual Copper Production 94,600 Tons Annual Molybdenum Production 15,000,000 Lbs. Annual Silver Production 1,135,000 Ounces

Jan 1, 1976

By Edgar A. Scholz

The purpose of this paper is to make a comparative cost analysis of domestic and foreign exploration projects which developed into mines during the 1960-1974 time period. A total of 18 mining companies, American and Canadian, were approached to solicit cost data on domestic and foreign exploration projects which developed into mines. Only 20 percent of the companies to which questionnaires were sent made data available. Several companies answered negatively, informing us that they would have difficulty in attempting to sort our costs. Some companies were usable to release cost details. It is comforting, however, to realize that some of the non-contributing companies expressed eagerness to hear the findings of this paper. Inasmuch as the data available on exploration expenditures is, in some cases, somewhat uncertain and that no two mining companies follow the same system of cost allocations, the results obtained in this analysis should he interpreted as trends of a general character.

Jan 1, 1976

By Whitmell J. Smithwick

Lime is one of the most extensively used chemicals in industry. Other than sulfuric acid, it is used in greater quantities than any other man-made industrial chemical. In 1974 there were 20,368,000 tons of lime used in the United States, which amounts to approximately 190 pounds for each man, woman and child in our nation. Lime also is perhaps the most diversely used of any industrial chemical. It is used in such areas as pharmaceutical, chemical, steel making, glass making, production of copper and aluminum, sugar refining, agriculture, construction, ecological endeavors, potable water treatment and sanitation. Figure I lists the major uses of lime for 1974, which is the latest year for which this data is available. The impact of the use of lime for ecological reasons did not show up to any appreciable extent in 1974, but we expect this to be a significant factor within the next few years. Fortunately, in the United States and also in most of the world, there are many deposits of high quality limestone available for the production of hood quality lime. For this discussion, we will assure that a limestone of a suitable quality and size consist will be available in a storage bin or stockpile near the kiln. Quality requirements for the lime product will be covered. We also will give a brief description of the three most popular types of lime calcining systems, how they function, and expected lime product quality from each of these. Commercial fuels and major accessory equipment will be discussed briefly.

Jan 1, 1976

By H. E. Hawkes

Reconnaissance mineral exploration based on the distribution of ore metals in stream sediments has become a generally accepted method of mineral reconnaissance. This approach seems to work almost equally well in all climates and in all kinds of terrain, provided of course that the ore deposits being sought are exposed at or near the surface and are actively undergoing erosion. Nobody with any experience in the field would question the validity of the concept on which stream sediment reconnaissance is based. Considerable dispute does arise, however, when the subject of density of sample sites per unit area, or sample spacing, comes up for discussion. What is the optimum balance between completeness of coverage and cost? The tacit assumption is frequently made that a greater sample density necessarily leads to more complete coverage and hence a lower probability of missing an important discovery, without regard for the size of the stream sample or the topology of the drainage pattern. The purpose of this paper is to attempt to bring the problem of site selection in stream sediment sampling into better focus, and to present a formula that may help in planning reconnaissance programs.

Jan 1, 1976

By E. J. Wasp

An upsurge of interest in slurry pipelines to move coal from Wyoming, Montana, and Colorado to markets in the southwest, west, midwest and northwest has recently developed. Specific pipelines have been proposed to serve these markets; the routes of these lines are depicted in Exhibit I. It is, therefore, timely to discuss some technical aspects of the terminal facilities for these western coal pipelines. The discussion will be based on experience with the Ohio and Black Mesa pipelines as well as detailed planning and testing for a proposed 1,000-mile system from Wyoming to the middle south area. The economics of the pipeline terminal processes are heavily depend¬ent on site, type of process used, and other specifics of the situation. However, the following approximate breakdown of costs for a 1,000 mile, large capacity pipeline will be useful for orientation purposes. [Water supply 4 Coal cleaning 5 Feed preparation 10 Slurry transportation 72 Dewatering terminal 9 100%]

Jan 1, 1976

My first regular job nearly fell through. My parents were spending the summer in California and I joined them at Lake Tahoe where we were guests at the lovely summer home of the Reids of Belmont. The time went quickly but I was eager to start work so I left for Bisbee a few days earlier than I had arranged. This was lucky, as just after I left a letter came from Gene Whitely, chief engineer of Calumet and Arizona, saying that because of the depressed copper industry there would be no job. I reached Bisbee on a Saturday morning, a day or two before my 23rd birthday, July 27, 1907. The brown plastei four-story Copper Queen Hotel was only a few steps from the station where the branch railway ended. I rented the cheapest room on the top floor and, of course, there was no elevator. I soon learned how to walk up the mile of switching tracks to the Calumet and Arizona office at the Irish Mag mine. I was horrified when Whitely told me about his letter telling me not to come, but since I had not received it he relented and said I could work for a short time anyhow. I was to start at 7:30 the next Monday morning, "holding the ignorant end of the tape”-in other words being surveyor's assistant, at $100 a month. Hours were from 7:30 to 5: 00, seven days a week. I spent Sunday walking around the town. I rented a room at the Royal Lodging House, which was cheaper than the hotel. It smelled strongly of carbolic acid but that meant no bugs. Compared with Cobalt or Cripple Creek, Bisbee didn't seem unattractive. The main street, with one or two-storied stores and saloons, followed the bottom of the canyon with high steep hills on both sides. My lodging house was on a rock in a narrow spot in the canyon, discouragingly called Tombstone Canyon. Chihuahua Hill, opposite the

Jan 1, 1976

By Raymond P. Miller, David L. Monson, Robert A. Robinson

A geotechnical instrumentation program consisting of borehole extensometers and portable tape extensometer stations was effectively used to monitor concrete liner deformations and guide construction procedures during enlargement of a 75-year old Union Pacific Railroad tunnel in Wyoming. Enlargement involved excavation of the old concrete invert and placement of 5,941 feet of new concrete invert 6 feet lower in squeezing shales, fault zones and water-bearing sandstones. Instrumentation data were used to guide procedures for excavating the old invert, installation of temporary interior struts, underpinning existing liner walls, and placing the new concrete invert.

Jan 1, 1976

If it had not been for the almost unbelievable adventures that came before and after, the last ten months of 19 15 would have been exciting enough for anyone. As it was they were a cheerful interlude. I spent most of the time on our Warren operations catching up on a lot of underground work and visiting Ajo every few weeks to see if my Chuquicamata visit might help solve the New Cornelia problem. While the difficulties were finally solved, at times they seemed almost hopeless. About all I could do to help was to make sure that the ore sent to the pilot plants represented the average ore that must be treated in the final 5000 tpd mill. Dr. Ricketts and John Greenway worked tirelessly with the best consulting advice they could obtain. Credit for the final success was due chiefly to their efforts. Since our old group had given up its "Merry Widow" home in Warren, a few of us got rooms in the company-built Cole Building over the Warren grocery store. This included Jim Lewis, Roy Mitchell, Steve Landon, Paul Stevens, and Hubert d'Autremont who came from Duluth to join our legal staff. Later we rented a small house two blocks from the Calumet and Arizona office. With the now flourishing country club only a 10-min walk away, and an electric car running to it every half hour or so, we were able to give parties in return for the hospitality of our friends. One of the most pleasant episodes came by luck a few days after I got back from Chile. Chester Congdon, a leading director in Calumet and Arizona, with his wife and their daughters, Elizabeth and Helen, spent a couple of days at the Greenway house before making an auto- mobile trip across the desert from Tucson to Ajo. At the same time I arranged to examine the small but rich Bush and Baxter copper mine a few miles from Tucson. At a party in Warren we found we would all be staying at the Santa Rita Hotel in Tucson, and I took my South

Jan 1, 1976

By J de Cuyper, E. J. Parkins, H. L. Shergold, W. Freyberger

The paper is divided into two parts. The first part describes an investigation of the effect of temperature on the conditioning and flotation of an ilmenite ore with a 1:l oleic acid-fuel oil mixture as collector. During conditioning the pulp underwent characteristic changes of flocculation, deflocculation and dispersion which were monitored by measuring the power consumption of the conditioner motor. Optimum flotation results were obtained at the end of the deflocculation period. High ilmenite recoveries were obtained at high temperatures and high concentrate grades at low temperatures. The second part of the paper describes a study of the effect of temperature on the adsorption of oleic acid at the ilmenite/water interface. At high adsorption densities it was chemical and exothermic. Contact angles showed that the hydrophobicity of the collector-coated minerals increased with an increase in temperature.

Jan 1, 1976

By N. Finkelstein, D. A. Hinckfuss

The large and compact but simple Bougainville Copper Limited flotation circuit has been in operation for 3-1/2 years. Discussion of problem areas encountered since start-up and remedies that have been implemented or proposed, form the main basis of this paper. Full cur- rent operational data is also provided.

Jan 1, 1976

By J. Herbst, I. Heber-Panu, Dan G. Cojocariu, E. Ene-Danalache, G. Poling

A general model which represents not only batch but also continuous flotation in multi-cell machines is presented. This model considers both the size distribution and the distribution of flotabilities in a size class for valuable mineral particles in the pulp. The general expression is shown to reduce to several previously reported models. In addition, a number of new models are found to arise for different specific assumptions concerning the flotability distribution and/or the size distribution of the particles undergoing flotation. Several of these new models are tested experimentally using laboratory-scale batch and pilot-scale continuous data. Model parameters are estimated from this data and a comparison of calculated recoveries and those experimentally determined are presented. Finally, the influence of the feed rate, aeration rate and valuable mineral content of the feed on the recovery is examined.

Jan 1, 1976

By J. Herbst, K. Fallenius, G. Poling

Since 1970 a new series of pneumo-mechanical flotation machines has been developed by Outokumpu Oy. The cells have a completely new type of mechanism based on a recently-developed theory of conditions necessary for dispersion of large amounts of air. The mechanism was developed in 3 cu m cells and scaled to 16 cu m cells. Rotor and stator description, scale-up theory, and practical experience with the 16 cu m cell are presented.

Jan 1, 1976

By Richard L. Bullock

Drilling of small diameter blast holes in the conventional tunnel driving system or mining operation still consumes a significant part of the time and money required to extend an opening in rock. The use of pneumatic drills for most small hole applications has been the dominant tool used by miners and tunnel men alike throughout the world. But now, a, trend has been started that is showing major inroads into the traditional areas of pneumatics drilling for all types of rocks. Operators dealing in very soft materials, such as coal, salt or potash, traditionally had the option to use hydraulic power for their drilling tools. Twelve to fifteen years ago, drillers in medium hard, but nonabrasive rock extended their drill machine option by helping to develop a drill that still used air to power the hammers, but relied on hydraulic power for the rotational torque and feed thrust. (1) This was a significant step forward, particularly for those who drilled in rocks that were compatible to rotary-percussion bits. However, this application was in fact somewhat limited to the limestone and dolomite formation of mid-United States and the softer sediments in Europe. Now high performance rock drills have been developed, using all-hydraulics for both the hammer and rotation, that have many advantages over the conventional pneumatic systems. In two previous papers on this subject, (2)(3) this author reviewed in detail: 1) the characteristics of each of the manufacturer's products that were on the market; 2) The specific advantages of the all-hydraulic drilling systems; 3) Data from the applications of these drilling systems that was in use; 4) What was needed to further develop this drilling system and utilize its potential in the mining or tunnelling cycle. This paper will attempt to update previous papers, without reiterating many details of drill descriptions or

Jan 1, 1976

By John F. Shea

When Dick Robbins asked me to give a keynote address, I felt it might be in order to review some of the practices and techniques used in tunneling and work up to some of the concepts now used to mine and construct tunnels. Needless to say, there have been many changes in tunneling technology and also many changes in the Safety Codes controling them. An example of this latter change was the fact that in 1931, my father excavated the Owyhee Tunnel No.5 with gas locomotives. He was able to do it because there was no natural gas in the rock and the ventilation system was designed to free the tunnel atmosphere from powder and exhaust fumes. Today OSHA rules would never permit gas locomotives underground, although there were no incidents on this particular project. One of my first tunnels, as Project Manager, was the Clear Creek Tunnel for the Bureau of Reclamation. Our method of handling muck was the Conway Muckers. This unit was a valuable improvement to the hand mucking of previous generations. The Conway was also used in our Navajo Project, in New Mexico. Unlike the Clear Creek project, where water was one of our main problems - up to 7,200 gallons per minute, at a pressure of 395 pounds per square inch - in the Navajo Tunnel, we had a mixed face which caused a major problem with our support system. In one of the Navajo Tunnels, there was a major cave-in, when the squeezing shale came in during an attempt to strengthen the support system. Although moving shale was not a constant problem, there were areas where the shale was five to six feet above the spring line.

Jan 1, 1976