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This report summarizes the results of a research project entitled "Fatal Accident Data Base Development." This project is the last project under Contract No. S0110601. Volumes I and 1I, "Industrial Engineering Study of Hazards Associated with Underground Coat Mine Production," summarize the original industrial engineering project and the Fatal Accident Report Analysis project. These projects were completed and accepted by the U.S. Bureau of Mines on December 10, 1971. Both volumes of the report have been made available by the Bureau to the public through the U. S. Department of Commerce technical information service. Another project under the same con tract, entitled "Equipment Operations Safety Study, ' was completed in January 1972 and the report was accepted by the U. S. B. M. at that time. The analysis in this Natal Accident. Data Lose Development report is closely related to analysis in both of the earlier reports. The original project involved an industrial engineering and safety of production operations for a representative sample of underground bituminous coal mines. The contactor was required to make recommendations 'in work practices, mining methods, equipment, and safety practices which can effectively reduce the fatality rate from rib and roof falls.' (Longwall mining methods were excluded from the study.) Time study and work element analyses were performed in over 50 mines as part of the field data gathering effort. Another requirement of the study was to develop sets of multiflow. Process charts, which are diagrammatic illustrations of the time-related interaction of mining, cycle job elements.

Jan 1, 1972

By Felix duBreuil

The present sampling procedure for evaluating the rock dusting conditions in a coal mine is time consuming. This study considers means by which this procedure could be simplified. Surveys were conducted in six coal mines in Pennsylvania to determine the in¬combustible content of the deposited dust. Some 2,000 samples were analyzed and statistically evaluated. It is suggested that the mean incombustible content could be obtained with fewer samples and smaller samples without greatly increasing the sampling error.

Jan 1, 1972

By George J. Thompson

Almost all persons connected with mining industry have had an exasperating experience like the following: 'On a cold and frosty morning in mid-January, you find yourself quite happy with the world. Production is up and the mine has been running smoothly. All at once the radio cracks up your tranquility -- 'so and so' piece of equip¬ment has broken its 'whatzit'. Now the iron is in the fire, and things have to be fixed quick.!' This can be a major failure which will bring the whole operation to a grinding halt or just one of the numerous maintenance headaches on an auxiliary piece of equipment. After one has experienced a major or minor catastrophe, he has to wonder whether some other methods with respect to design and maintenance would help prevent these unexpected calamities. The objective of this paper is to gain an insight into the charac¬teristics of steel at cold temperatures so that better decisions can be made with respect to maintenance and repair of mining equipment. Most machinery and their structures are exposed to cold temperatures. Even in locations as far south as Alabama and Arizona, brief periods of cold in winter months can adversely affect the ability of mach¬ines to do their work. To understand the background of cold temperature brittle fracture, jet us examine its basic elements. First, when steel gets cold, it gets brittle. This is best described by Figure 1. This graph shows a typical stress/strain curve of a mild or medium grade steel at room temperature. Stress is defined simply as the amount of force acting on one square inch of

Jan 1, 1972

By Charles V. Riley

While the late 1960's are known as the years of the public recognition of impending environmental crises, the 1970's will be known as the decade of public concern for improving the quality of that environment. One of the present major environmental concerns is the temporary disturbance resulting from coal surface or open cast mining. To realize that this concern will continue in the future, one need only observe the daily news media. Increasing energy demands in the U.S., a doubling of electrical power consumption each decade during the present century, and the projected needs for the remainder of the century are indica¬tions that coal surface mining as a major extractive industry will continue. Coal and lignite, prime energy resources and extremely abundant in these United States, in the face of seemingly limited gas, oil and uranium reserves, are both destined for expanded future use. Presently some extremely serious techno-logical and environmental problems are associated with the develop¬ment and use of nuclear power. It is true that the extraction and use of coal as an energy fuel poses disruptive problems for the environment, but the solutions to many of the problems are known or can be solved within a reasonable time framework. Certainly our national well-being and continued survival, as a free nation within the world community, automatically dictate the continued use of the coal resource for energy. Concurrently, those engaged in coal surface mining, with the temporary disturbance of the land and water resources, must also realistically conclude that public concern for maintaining and improving the quality of the environment will not diminish. Although as ecological, economic, social and aesthetic elements

Jan 1, 1972

By Kermit Allen

Historically, major natural gas transmission companies have been faced with the problem of meeting peak demands when the source of natural gas is located hundreds of miles away from the marketing area. Transcontinental Gas Pipe Line Corp.'s position was further complicated when offshore gas supply wells were shut-in during hurricane alerts. Transco's solution to this problem was the construction of salt storage wells adjacent to their pipeline near Eminence, Miss. Storage caverns were constructed using conventional solution mining methods. Two 13 3/8-in.-diam cased wells were completed and a 1,000,000-bbl cavern was leached at an interval of 5700 to 6700 ft at the base of each well. The two caverns have a usable storage volume of 2.0 billion cu f t and each well has a deliverability rate of 375 million standard cfd. The caverns are unique in that brine is not used for product displacement-all brine has been removed from the caverns. Natural gas is stored at a maximum pressure of 4000 psia. During withdrawal the cavern pressure drops to a minimum of 1225 Asia-the volume of gas between these two pressures becomes "usuable or top gas." The Eminence storage terminal is located on the Eminence salt dome about 30 miles north of Hattiesburg, Miss. Construction began in July 1968 and was completed in October 1970.

Jan 1, 1972

By Fun-Den, Wang

An open pit rock structure usually contains geological planes of weakness. They are formed by joints, faults, bedding planes, fractures, and cleavages. Rock slope failures often occur in the form of sliding of rock blocks along a plane or several planes. Such a rock block has three- dimensional geometry, and consequently a vector method of analysis has been found useful in evaluating its stability. Rock blocks of a tetrahedral shape with one free surface have been analyzed by Londe. Rock blocks formed by sets of parallel joints have been analyzed by Wittke. The present chapter presents the analysis of rock blocks formed by planes of weakness of arbitrary orientation, and of three-dimensional geometry.

Jan 1, 1972

By W. J. LANGRON

This paper describes the results of VLF-EM test surveys, using the Ronka EM-16 equipment, over a selection of environments in Australia and Papua.Using comparisons with known geology, drilling information and other geophysical work it is shown that the maximum depth of penetration of the method is about 100 ft but is considerably less than this in most areas.The author believes the method could aid in geological mapping and provide a useful adjunct to aeromagnetic surveying in some areas.

Jan 1, 1972

Increasing demands on quality of metallurgical grade alumina and for lower production costs led to the development of a new fluid bed calcining process. The process, jointly developed in Germany by Vereinigte Aluminium Werke A. G. and Lurgi Gesellschaften m.b.H., takes advantage of modern chemical engineering methods such as counter-current flow of combustion air and solids, direct heat-exchange between combustion air and fine solids, and near stoichiometric combustion of oil in a fluid bed. Using a two-stage Venturi-type suspension preheater for heat-recovery from combustion flue-gases, the circulating fluid bed technique with internal oil combustion at 220°F for the calcining step and a five-stage fluidized bed cooler for heat-recovery from calcines, the process gives an outstanding heat-efficiency. In a first industrial plant for 560 sh. tons/day of alumina heat consumption figures of less than 1·400 B.T.U./lb Al203 g were achieved.

Jan 1, 1972

By R WOODS

The interaction of, flotation collectors with sulphide mmerals takes place at the solid-solution interface. The electrochemistry of the processes which affect this interface are discussed. The interaction of xanthates with sulphides is an electrochemical process, xanthates being electro-oxidized to chemisorbed xanthate and dixanthogen.The role of oxygen is to provide a cathodic process to allow the anodic oxidation to occur. The hydrophobic condition of the mineral surface is brought about by the presence of the oxidized xanthate species. The action of reagents which can activate or depress the flotation of sulphides is discussed briefly.

Jan 1, 1972

By Earle J. Klohn

"The design, construction and operation of tailings dams is rapidly becoming a major consideration for most new mining developments, as well as for many existing operations. In North America, under pressure from public opinion, various government agencies have in recent years enacted legislation covering the design, construction and operation of tailings dams. In British Columbia, comprehensive legislation has been passed during the past year (1971). All of these new regulations may be placed into two broad categories: regulations concerning the safety of the dam and appurtenant structures, and regulations concerning the prevention of pollution. Both types of regulation affect the design of the tailings dam facilities. Consequently, they must be considered jointly by the designer. A good tailings dam design must satisfy the basic requirements of safety, pollution control, storage capacity and economy. To achieve this, 'the design must be based on a thorough understanding of both the geotechnical problems involved and the requirements of the mining development. Obviously, this requires close cooperation between the designing geotechnical engineers and the mining operators. This paper outlines the major engineering factors that should be considered in the investigation, design, construct ion and operation of tailings dams. Basic methods of tailings dam construction are reviewed and the advantages and disadvantages of each briefly discussed. Comparisons are made between the design and construction of conventional water supply dams and tailings dams. Examples are presented of some of the problems that may arise during construction and operation of a tailings dam. The paper also explains the need for basic instrumentation of tailings dams and for carrying out simple field tests and measurements during construction and operation. Of prime importance is the downstream monitoring of surface and subsurface seepage flows. These observations are invaluable where contamination of surface and/or subsurface water may become a contentious issue at some future date. Each tailings dam design must be based on a study of the particular requirements of that project. To make a proper evaluation, adequate data must be available concerning a large number of items•, including such things as: topography, hydrology, geology, subsoil properties, seismicity, government regulations, fineness of mill grind, mill water balance, availability of suitable construction materials, volume of water to be stored behind starter dam, downstream development or liability, and many others. The large number of variables involved in such an evaluation often result in the designer considering two or more alternative designs. Selection of the final design, which is usually based on detailed cost analyses of the alternatives, must be made in close consultation with the owner."

Jan 1, 1972

By Donald Crowell

Due to falling metal prices and depletion of ore reserves, lead-zinc mining in the Leadville, Colorado, area gradually came to a halt in the 1950's. Exploration work continued, however, and by 1969 sufficient ore had been blocked out to warrant sinking a shaft and erecting a new concentrator to treat 700 tpd. The new shaft and concentrator were to be located in Iowa Gulch several miles east of Leadville at an elevation of 11,100 ft. The Leadville project is a joint venture between Newmont Mining Company and ASARCO with ASARCO being the operator. Design work began in the fall of 1969. Engineering was done by Torkelson Engineering Company of Salt Lake City in conjunction with the Central Engineering Department of ASARCO. The plant was constructed by Stearns-Roger Corporation. Construction began in the spring of 1970 and the plant went onstream in April, 1971. Flow sheets and equipment lists are attached. This paper will describe the flow sheet very briefly and discuss in more detail those aspects of the design which may be of interest, particularly the provisions for expanding the capacity of the plant.

Jan 1, 1972

By Carl E. Bagge

It is easy for a coal spokesman to relate to the theme of this meeting--that the decade of the 1970's is pivotal for the mineral industries. For the coal operator, this period is crucial. The coal industry, according to most energy forecasters, must gear its production machinery to meet a sharp rise in the demand for coal--in this decade to sustain inevitable boosts in electricity output, and in the next to start supporting a big new domestic synthetic fuels industry that is already in the formative stage. The logic of that projection flows from a combination of hard circumstances--proved reserves of domestic fluid fuels are dwindling, the hope for bountiful and cheap nuclear power must be indefinitely deferred, and the threat of long-term fuel imports to the national interests is becoming starkly visible. Only coal, with its assets of abundance, security and versatility, offers the nation an adequate and immediate lift out of its current energy crisis. A hard-won expansion of coal production made the critical difference between local power load-shedding and major area blackouts in 1970, the year the energy crisis went public. Coal will have to play that same key role, not just through this pivotal decade but through the turn of the century. But the logic of fuel demand apparently does not always extend to supply. The coal industry has had a huge production job laid out for it by the energy statisticians, but up to now the energy policy-makers have not followed through with the aids and inducements that the coal operator urgently needs to do that job well and completely.

Jan 1, 1972

By Jay F. Smith

The Alan Wood BOF Shop consists of two 140 ton furnaces with a rated yearly capacity of 1-1/4 million ingot tons, he hot metal for the BOF Shop is supplied by two 18 foot blast furnaces which produce an average of 2000 tons per day, To achieve the rated ingot ton capacity with this limited supply of hot metal, the preheating of scrap is necessary. This is accomplished in the furnace by using an oxygen-natural gas burner. Piping Arrangement The natural gas and oxygen are piped into the Shop through 8-inch lines to their respective valving stations. As can be seen from Figure 1, the flow of natural gas passes through a flow control valve which is common to both furnaces, after which it divides into two 6-inch lines forming two identical and independent gas control lines, one for each furnace.

Jan 1, 1972

By J. Marshall Rounsevell

It is probably not too far from the truth to say that the sulfur content of the steel bath at the first turndown of the basic oxygen furnace is influenced by every factor which varies in the operation of a BOF shop. However, the determination from normal shop operating data of the effect of a given factor on turndown sulfur content requires a means for collecting a large quantity of such data and a significant variation of the factor in question in that data. In this paper, operating data from 4000 heats collected on the computer at Inland's No. 4 BOF Shop is utilized to analyze the effect of four operating parameters -- hot metal sulfur content, hot metal manganese content, percent burnt dolomitic lime (dolomite) in the flux charge, and the presence or absence of transfer ladle slag skimming -- on first turndown sulfur content.

Jan 1, 1972

By Richard L. Stowe, Donnie L. Ainsworth

The static, rapid, and shock-loading response of rock is of interest to many in the field of rock mechanics. For example, the effects of loading rates on strength and stress-strain characteristics of rock are quite important in defining input loading for use in the design of underground protective installations. Response data on rock subjected to shock loading over a wide range of pressures are also vital in the field of underground nuclear testing. In addition, material response is needed in design of shock-absorbing liners. A number of investigators have reported that ultimate compressive strength of rock increases with increased rates of loading.1-6 Wuerker3 stated that modulus of elasticity, obtained from sonic determinations, increased in some rocks by a factor as high as 4.5. It appears that only a limited amount of work has been done on comparing static modulus and modulus obtained from impact testing.6 Phillips4 showed that with increased rates of loading the deformation decreased. More recent work by Atchley and Furr5 showed that when moderate-strength concrete is stressed with increased loading rates, the axial strain at failure increased. One would expect this to occur if we think in terms of purely elastic materials. For example, if E is constant and maximum strength [amax], increases, the axial strain would also increase. However, in rock testing thus far we have worked almost exclusively with nonhomogeneous and inelastic rocks. From this fact alone the increase in axial strain with increased load application is noteworthy.

Jan 1, 1972

"The rocks of Notre Dame Bay form part of the Central Paleozoic Mobile Belt (Williams, 1964) of the Newfoundland Appalachians. The Central Paleozoic Mobile Belt of the northern part of the island consists predominantly of Lower and Middle Ordovician rocks overlain by Silurian elastic and volcanic sequences and underlain in the marginal zones of the belt by polydeformed metamorphic rocks of the Gander Lake Group (Kennedy and McGonigal, 1972) in the northeast and the Fleur de Lys Supergroup (Neale and Nash, 1963; Kennedy, Phillips and Neale, 1972) in the northwest. The Ordovician rocks of the Central Mobile Belt have been subdivided into a number of local groups in different parts of the region. The Lush's Bight Group was first defined by MacLean (1947) . Recently Marten (1971) has revised the definition of this group, as shown in Table 1 and his revised definition is accepted in the present paper. Plate tectonic models that have been proposed for the development of the Newfoundland Appalachian System have indicated that the mafic volcanic rocks of western Notre Dame Bay represent oceanic crust (Bird and Dewey, 1970; Dewey and Bird, 1971; Church and Stevens, 1970) which marks the remnants of the proto-Atlantic Ocean first proposed by Wilson (1966) . Such models infer that the mafic volcanic rocks constitute the upper part of an ophiolite sequence. Analyses of the lavas show that they are tholeiitic and support this conclusion (Papezik and Fleming, 1967; Smitheringale, 1972) . A complete ophiolite sequence, consisting of peridotites overlain by gabbros, overlain by a sheeted diabase dyke complex which passes upward into pillow lavas, occurs at the base of the Snooks Arm Group (Upadhyay et al., 1971 ) . Sheeted diabase dykes are known to underlie the lowest mafic pillow lavas of the Lush's Bight Group at several localities in Notre Dame Bay (Strong, 1972, and pers. comm.) . However, several conflicting points about the geology of this region suggest that although a typical oceanic crustal sequence of Lower Ordovician age is present, older rocks occur within the ophiolite terrane in several places (Williams, Kennedy and Neale, 1972) ."

Jan 1, 1972

By J. A. MacLellan

"CONSTRUCI'ION OF SHERRITT'S CONCENTRATORSSherritt Gordon is operating two mills north of the 56th parallel, and is presently engaged in building a third. The author was closely involved in the design and construction of all three of these concentrators.The Lynn mill is the oldest of these three concentrators-it is a 4,000 ton per day nickel-copper plant built in 1953. The Fox mill is a 3,000 ton per day copper-zinc concentrator built in 1970. The Ruttan mill will be a 10,000 ton per day copper-zinc plant scheduled to go on line in July 1973.LYNN MILL The Lynn mill including the crushing, concentrating, drying and load out plant is about 69,700 square feet or 17.4 square feet per ton per day. '!his plant was originally built in 1927 at Sherridon, 150 miles south of Lynn Lake, as a 2,000 ton per day copper-zinc plant. In 1952 the plant was moved by tractor train to Lynn Lake. The whole plant was re-oriented within the original perimeter walls as a 2,000 ton per day nickel-copper plant. This plant was expanded to 4,000 tons per day by the addition of t1-Jo rod mills and a 5-1/2 short head crusher in 1959.The Sherridon mill processed its last ore in Sherridon in September 1951 and the first load of nickel concentrate was loaded at Lynn Lake on November 9, 1953 when the railroad arrived at Lynn Lake.The site for the Lynn Lake mill was cleared of overburden in the summer of 1952 and foundations for structural steel and SO!l8 equipment foundations were poured the late summer and fall of 1952 • Steel was erected from January to June 1953. Most of the equipment came in from January to March of 1953 by tractor sleighs. Sane sleighs upset but no equipment was lest through the ice."

Jan 1, 1972

By D. L. Morgan, J. A. Butterfield

"Geological data, production trends and current projects underway suggest that enough molybdenum will be available from more diversified sources to meet the world's growing demands. The growth in molybdenum consumption has been primarily related to its beneficial effects as an alloying agent in steel. This rapid growth has been deliberately fostered by stable prices, adequate supply and application research. The molybdenum industry is now in a process of change which has been seen in several other metals, such as aluminum and nickel. As supply sources have become more diversified, the market has become more competitive. The recent drop in consumption has led to excess production capacity, accumulation of substantial producer inventories and increased market uncertainties. While consumption is expected to increase in the next two to three years, it will take some time to absorb the excess capacity and inventory. The increased proportion of by-product capacity indicates that prices may become more variable. Producer discipline will be required to prevent serious price erosion in times of surplus. Future prices may not continue to increase with inflation. For the longer term, several factors favour the increased consumption of molybdenum. Engineering requirements are becoming more severe and molybdenum alloys can help to meet these changing needs. In addition, consumers can rely on a large and increasing supply of molybdenum. A 7 per cent growth rate in consumption can probably be sustained through the next decade, but new applications and reasonably stable prices will be needed to make this possible."

Jan 1, 1972

By M. B. Kahle, A. D. Pernichele

Four types of slope failures in waste dumps are recognized debris flow, foundation failure, edge slump, and blowout. The first three types, although at times causing considerable damage to property and interfering with mine operations, are not usually dangerous to personnel because of their slow rate of movement. The fourth type, the blowout, is the most dangerous because of its explosive mode of failure and lack of forewarning. The December 1969 failure at Verona dump is presented as an example of a blowout. Data from piezometer holes indicate that the blowout was due to perched leach solutions near the face of the dump. The level of water in this zone is very closely related to the rate of leach water application on the dump. A detailed analysis of core samples indicates that the impounded water was perched on a zonal accumulation of jarosite which is associated with a buried dump surface. Drain holes proved successful in controlling perched leach solutions in the critical zone near the face of the dump. Monitoring of the water level in the perched zone is considered essential in preventing blowouts. The use of drain and piezometer holes has allowed an increase in the rate of water application on the dump while preventing additional failure.

Jan 1, 1972

By Sam H. Patterson

Fuller's earth and bentonite are two clay commodities that are interrelated either by mineral composition or use. Because of this interrelation and the sale of both for many different uses, some ambiguity in their classification has resulted. The term "fuller's earth" has no compositional or mineralogical meaning, and it is used more or less as a catchall for any clay or earthy material suitable for certain uses. Most, but not all, of these uses require absorbent properties. Bentonite by geologic definition must have formed from volcanic ash or tuff or the glassy material in volcanic rock; most bentonites consist chiefly of montmorillonite but other clay minerals may be present. In industrial usage the term "bentonite" is applied to any clay consisting chiefly of montmorillonite, irrespective of origin. Georgia and Florida have historically been the leading States in the production of fuller's earth; bentonite has been produced in Alabama on a small scale. The first major use of fuller's earth was in refining of oils. Other materials have replaced fuller's earth for this purpose to a major extent, but many new uses for fuller's earth have been found, and production has increased in recent years. The new uses include absorbent products, insecticide and pesticide carriers, drilling mud, and many others. The bentonite now produced in Alabama is of the "southern," "low selling," or "calcium" type and is used mainly as foundry-sand bond. Most of the fuller's earth mined now is in the Hawthorn Formation of Miocene age; a lesser amount is produced from the Twiggs Clay Member and other beds in the Barnwell Formation of Eocene age. Inactive pits from which fuller's-earth was produced from other formations occur at several localities. The bentonite now mined in Alabama is in beds of Cretaceous age; several years ago bentonite was produced from Eocene beds in this State.

Jan 1, 1972