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By H. W. Turner

The axis of the middle portion of the Ural mountains is made up chiefly of highly compressed igneous and sedimentary schists, considered of Devonian age by the Russian geologists, with large areas of serpentine (peridotite originally) gabbro, etc,, intrusive in the schist series. In addition there are large areas of probably older granitic and gneissic rocks. The nickel deposits referred to in this paper are found in the Devonian schists and their associated igneous rocks. The gabbro-peridotite intrusions probably took place in late Devonian or early Permian time, inasmueh as the Permian and Carboniferous beds lie at gentle angles on the Devonian series on the west slope of the Urals. Perhaps the first attempt to work a nickel deposit in the Urals was made about 1866 in the Revdinsk district, which is situated southwest of Ekaterinburg. 3 was informed by a Russian that a wet method of extracting the nickel was tried but was not a commercial success. This deposit has been described by Muller,l Foullon, and Karpinski.3 Beck4 gives an abstract of these papers. ; Lying to the southeast of the Revdinsk district, the Sissert estate intervening, is the Verkhne-Ufalei district, which is traversed by the railroad from Ekaterinburg to Cheliabinsk, as shown on the map, Fig. 1, there being a station on this railroad at the iron-smelting town of Verkhne-Ufalci. About 7 versts (4.6 miles) north of this town is the Nijni-Karka-dinsk iron mine, which is a limonite deposit. In one of the shafts in this mine a serpentine rock showing a green mineral was encountered. A sample of this mineral collected in 1910 was tested by Mr. Wyatt, chief chemist of the Karabash laboratory of the Kyshtim Mining Works, and determined as nickel ore. A thin section of one piece of the serpen-

Jan 1, 1915

STANDING COMMITTEES Executive-A. R. LEDOUX, chairman. Membership-GEORGE C. STONE, chairman. Finance-J. V. N. DORR, chairman. Library-E. GYBBON SPILSBURY, chairman. Papers and Publications-BRADLEY STOUGHTON, chairman. Nominations-POPE YEATMAN, chairman.

Jan 7, 1919

By E. J. Yoder, N. B. Aughenbaugh, R. B. Johnson

Mineral aggregates experience degradation during field and laboratory compaction. Reduction in the aggregate size is accomplished by abrasion of the particle edges and fracturing of individual pieces which have become overstressed. Little is known of the factors that govern the amount of breakdown experienced for a given situation. A field study was made of the factors affecting aggregate breakdown under compaction using three carbonate aggregates of different physical properties. The preliminary results indicate that rock type, compactive effort, gradation, and thickness of compactive layer are factors which exert the greatest influence. Mineral aggregates experience a mechanical breakdown of some of the aggregate pieces into smaller fragments during any compaction process, whether in the field or laboratory. This phenomenon occurs as abrasion of the sharp edges during movement and reorientation of the particles in densifying and/or as granulation and fracturing of those pieces which have become overstressed. Two types of aggregate breakdown occur in the field. These may be classed in a general category of aggregate degradation.* One occurs during the con- * Aggregate degradation has been defined in many different ways. For this paper it is considered as any breakdown of larger particles into smaller ones, whether mechanical or chemical. struction period and is related to the densification of the aggregate body from a loose state to a relatively dense mass by heavy compaction equipment. This type is almost entirely a mechanical action. The other occurs after the construction period when the roadway has been put into use. This in-service breakdown is; a different phenomenon from the breakdown during construction in the sense that it combines mechanical with chemical changes. Time becomes an important consideration that may cause subordinate factors in construction degradation to develop into principal ones for in-service breakdown. Breakdown of aggregates in service has been extensively studied by investigators from the northwestern

Jan 1, 1962

By B. S. Butler

Apropos of metals low in the series illustrated by Dr. Butler's Table 11, it is interesting to note that Cress and Feldman29 reported traces of platinum metals in several samples of alunite. They found, chemically and spectrographically, several traces of platinum, palladium, and rhodium in alunite from Sugar Loaf Peak, near Quartzite, Ariz.; silver, platinum, and rhodium in alunite from Rio Grande County, Colorado; and traces of rubidium and gallium in various samples of alunite. These authors stated that the platinum metals appear to be present as Oxides and suggested deposition by hydrothermal solutions under near-surface conditions. AS described by Heineman,30 the wall rock of the Sugar Loaf alunite veins shows considerable alunitic alteration. Pyrite and hematite are relatively abundant in the wall rock but decrease progressively near the veins. Assays of samples of the Sugar Loaf alunite, run by J. B. Cunningham of the University of Arizona College of Mines, showed traces of silver and 0.002 to 0.004 oz of gold per ton, but the chemical form of the gold and silver in this occurrence remains undetermined.

Jan 1, 1957

By Y. C. Kim, S. L. Barua

Underground coal mine planning has traditionally focused on the mine design aspects concerning safety and efficiency in the quest to produce low cost coal. Very little attention has been given to coal quality control aspects of mine planning at most US underground coal mines. With the enactment of the Clean Air Act of 1970, the generally high sulfur content of coal has become a major concern for the coal-fired power plants in the east. Similarly, the ash and the Btu content of coal are equally important for boiler efficiency. Coal mine planning must incorporate coal quality control aspects as well as traditional safety and efficiency aspects. According to an article in Coal Age (March, 1982), nearly one-half of the US coal exported to Europe does not meet the contract specifications regarding ash, sulfur and Btu contents. Although one of the reasons cited for this problem was "inadequate sampling at the US ports," the more fundamental cause probably lies in the inadequate quality control of run-of-mine (ROM) coal at the source. To perform adequate quality control of ROM coal, mines need predicted short-term in-situ coal quality information. Such predictions are generally based on whatever available sampling information is around the mine workings. Unfortunately, the closest sampling information, in the form of diamond drill hole assays, is often several thousand feet away in most underground coal mines and is inadequate for short-term coal quality prediction purposes. This is because the diamond drill holes (DDH) were traditionally placed in the coal deposit during the mine development phase to determine coal seam continuity and overlying roof conditions. They were not placed for short- term mine planning. A study was undertaken by the University of Arizona for the Homer City Owners in Pennsylvania to show that there is a need for more closely spaced samples, if the short-term coal qualities are to be predicted with any "reasonable" degree of accuracy. Prior to this study, a short-term quality prediction model, STPM, had to be developed. This model uses not only DDH, but also other sample information obtainable during face development work to predict the qualities of in-situ coal that are available in the immediate future.

Jan 1, 1985

In the seven years that have elapsed since the AIME World Symposium on Mining and Metallurgy of Lead and Zinc, there have been a number of significant milling innovations and trends implemented in lead-zinc flowsheets to either improve grade and recovery or to control escalating mill costs. First, mill controls and instrumentation, which only had a foot in the door in 1970, have become increasingly common. In Australia, research into automatic crushing control has been implemented by Mount Isa Mines, and in virtually any large lead-zinc mill worldwide, an assortment of on-stream x-ray analyzers, grinding circuit controls, level detection devices, and reagent metering methods can be found. The increased circuit control offered to mill operators by this new technology points to more efficient flowsheets, as well as to a greater dependence upon computer-controlled operation.

Jan 11, 1977

By R. W. D. Clarke, J. C. Folinsbee

INTRODUCTION This paper deals with a procedure for planning the mining of an orebody for which cross-sections, plans, grade of ore, and a geological estimate of the ore reserve have been prepared. The procedure begins with the preliminary selection of a mining method or methods on which an engineering evaluation will be carried out. The engineering evaluation is described in three parts: Conceptual Studies Engineering Studies Detailed Design An overall planning model is presented, plus an expanded model for the Engineering Study Throughout the discussion of the planning procedure, reference is made to three bulk mining methods, including block caving, sublevel caving, and longhole sublevel stoping, including a summary of the main characteristics of each of these mining methods. The planning model is designed for a longhole sublevel stoping method, but with modification, will apply to other methods. PRELIMINARY SELECTION OF A MINING METHOD To experienced mining engineers, identification of the nominal mining method for a given orebody normally involves a large measure of judgement. The geological data is reviewed to determine the configuration of the orebody, including size, shape, dip, grade, and metal distribution. Geotechnical data is considered, including the competence of the ore and host rock, faults, fracture patterns, groundwater, and the potential for in situ stresses. Geographical data, including the natural and societal conditions, are evaluated for their effect upon the mining method, and finally, economic data, basically defined as the value of the ore in the ground, but more specifically, including grade of mineable ore, distribution of ore grade throughout the orebody, and metallurgical recovery, will have a bearing on the nominal method selected. Preliminary evaluation of these factors will result in the elimination of the obviously inappropriate mining methods, leaving some method or methods for further, more detailed study. Since ore does not occur in simple geometric shapes, the method selected for more detailed study will require some variation to the standard. A few key factors will bear heavily on the selection and provide a basis for the most realistic choice. Geological Data The configuration of an orebody defined by the horizontal and vertical dimensions, the dip and strike, and the possibility of repetitive occurrences will have the major influence on the selection of the mining method. For bulk mining methods, the dip of the orebody should be steep, or the orebody must be thick so that gravity can be utilized to deliver fragmented ore to a central gathering area. Geotechnical Data The geotechnical data will be studied in greater detail when the nominal mining method has been selected and the engineering evaluation is undertaken. However, some basic initial information must be available. The structural strength of the ore and host rock, including the effect on it of faulting, fracturing, and insitu stresses, must be known. Data from exploration drilling and examination of drill core will assist in the preliminary assessment of these factors. Highly fractured ground may suggest a caving method of mining for certain orebody configurations, whereas highly competent or strong ore might indicate that for a similar configuration, longhole sublevel stoping will more likely succeed. Data obtained on groundwater from exploration drilling will be considered to determine if it can be controlled, or if it will represent a long term major expense or a hazard for which no control is possible.

Jan 1, 1981

By Wilbur T. Stuart

THE increased demand for iron ore has necessitated a re-examination of ore-bearing lands on which the presence of water previously has indicated hazardous and expensive operating conditions. In view of the importance of iron ore production to the national economy and defense, the Ground Water Branch of the U. S. Geological Survey, in cooperation with the state of Michigan, began a study of mine drainage in the Iron River district in 1945, and later extended the work to the Marquette district. The purpose of these studies was to define the principles involved in the movement of surface and ground water toward the mined areas, with the hope that the information obtained in the research would lead to the development of methods of water control and to a reduction in the total mining costs.

Jan 12, 1951

INTRODUCTION The difference between a mineral inventory or mineral reserve and an ore reserve was discussed in the introduction to Chapter 10. The term ore reserve implied mineral in place that is capable of being mined at a profit. Potential profitability of in situ minerals is dependent upon several economic parameters in addition to grade estimates for blocks of the mineral

Jan 1, 1980

By Alan Stanley

R. T. Hukki (Finland Institute of Technology, Helsinki, Finland)—In the analysis of mill products containing minerals of appreciable difference in specific gravity the well-known principle of the method described by Stanley is applied in a number of ways for a variety of problems. The use of Le Chatelier bottle as explained in the paper may be a dependable and sufficiently accurate way, although no information is given as to the reproducibility of the specific gravity determinations. In the case of MacIntyre ore the method is applied for three separate products produced apparently without reagents and relatively free of fine slimes. Should it be applied for flotation products carrying a substantial amount of slimes, difficulties should be anticipated in the process of eliminating air inclusions from the sample. The difficulties mentioned above may be overcome by the use of a volumeter, an instrument designed for specific gravity determinations of finely divided solids in dry state. This instrument, see Fig. 4, is manufactured by F. Süffert-Bürner A. G. in Basel, Switzerland. Its operation is based on the law of Boyle and Mariotte. With the use of the volumeter, the specific gravities of test samples having a total volume of about 30 cm are easily reproducible within ±2 units in the second decimal of the specific gravity figure, and even better than that with utmost care. This accuracy is sufficient for ordinary operational control. How closely the specific gravity determinations follow the respective chemical assays depends primarily on the nature of the sample itself. In this respect no specific gravity instrument can give better results than those justified by the consistency of mineral distribution in samples analyzed.

Jan 1, 1954

By W. H. Forbes

As permissible explosives and electric detonators are now generally recognized as the only safe means of blasting in coal mines, this paper is limited to their use. Causes of Misfires There are many different causes of misfires, but the principal ones are as follows: 1. Explosives which have deteriorated through improper storage either at the storage magazine, the distributing magazine, or at the working face. This is not only true of the explosive itself, but also of its detonating agent. 2. Improper priming and charging at the working face. This commonly occurs when the explosives are handled by inexperienced persons. 3. Improper methods of tamping; the leg wires of the detonator may be abraded or broken by the tamping bar or stick, thereby causing a short or broken circuit. 4. Faulty leading wire, or electrical apparatus of insufficient strength to explode the detonator. Prevention of Misfires Storage is an important factor, especially with permissibles of a nitrate or ammonia base. Both explosives and detonators should be stored in substantially built, fire-resisting magazines and should be situated so that the minimum amount of moisture and heat is present. They should be so constructed that a constant supply of fresh air enters; the floor of the magazine should be raised to permit the circulation of air under the stored explosives. Boxes should be stored top side up and in such a manner that the old explosives are used before those of a later delivery. This eliminates chance of deterioration from lengthy storage. Detonators should be similarly handled and stored. The distributing magazine stock should be regulated so that not more than one day's supply is on hand.

Jan 1, 1930

By Hans E. Gustafsson

INTRODUCTION The Kiirunavaara iron ore mine is situated in northern Sweden about 150 km north of the Arctic Circle. The ore body has a sheetlike shape, stretches about 4000 m N-S dipping 60°E and has an average width of 85 m. The ore body is known to a depth of more than 1500 m. Mining at present has reached a depth of about 500 m. The mineral is a magnetite containing 66-68% Fe. The ore body was originally mined as an open pit from 1900-1957. From then on the mining method has been sublevel caving. Production for the last few years has been 20-25 million tons /year. Sublevel caving is a mining method with many merits. One of the most valuable is the ability of using a high degree of mechanization. Today, 25 years after sublevel caving was introduced at Kiirunavaara, the advantages of the method have been more or less exhausted, and the disadvantages are more obvious as the rock pressure increases with depth. One of the disadvantages is the high degree of waste rock in the hoisted ore. Today the waste rock content is about 25% by weight of which 20% comes from the caved rock. Second, we are calculating a relatively high loss of ore (20%). Third, selectivity is unsatisfactory when mining different grades of ore. Field testing sublevel shrinkage caving (MSTM) is primarily aimed at lowering the content of waste rock compared to sublevel caving. ECONOMIC TARGET A simple calculation shows that if the waste rock content can be lowered from 25 to 15% the operational costs of mining will be lowered by about 40 million SEK/year (US $9 million) at a production level of 20 million tons/ year. A 15% waste content is the target of the field test. In the long range a decrease in waste rock dilution will mean lower investment costs for deeper levels. DESCRIPTION OF THE MSTM MINING METHOD One reason for decision to carry out the field test was that with MSTM the development drifts from sublevel caving could be utilized and thus the project could start without delay. The only additional development work needed was the loading level. Fig. 2 shows a profile through the MSTM area 66-68% Fe. and Fig. 3 shows the loading level.

Jan 1, 1981

By J. C. F. Randolph

This mill being now in successful work, it seems proper to record some professional memoranda concerning it. It is intended to handle an unusual ore, in a locality difficult of access, and its arrangement and method of procedure present some novel features of interest. It was prepared for the San Miguel property at Batopilas, State of Chihuahua, Mexico, owned by the Consolidated Batopilas Silver Mining Company of New York, at present under the management of ex-Governor Alexander R. Shepherd. This property contains a large series of more or less parallel veins, worked through a deep cross-cut tunnel 1300 feet in length. The vein rock of these veins is calcapar in diorite. While, near the stirface, ruby silver, black

Jan 1, 1882

By John C. F. Randolph

THIS mill being now in successful work, it seems proper to record some professional memoranda concerning it. It is intended to handle an unusual ore, in a locality difficult of access, and its arrangement and method of procedure present some novel features of interest. It was prepared for the San Miguel property at Batopilas, State of Chihuahua, Mexico, owned by the Consolidated Batopilas Silver Mining Company of New York, at present under the management of ex-Governor Alexander R. Shepherd. This property contains a large series of more or less parallel veins, worked through a deep cross-cut tunnel 1300 feet in length. The vein rock of these veins is calespar in diorite. While, near the surface, ruby silver, black

Jan 1, 1882

By Harry A. Roe

THE power drag scrapers and the slackline cableway excavator have been called "long-range excavators." Broadly, their field of usefulness is restricted to work in which their long range of action permits them to operate economically, and which other, possibly more conventional, excavating units cannot do. Both of these machines dig or lift material and transport it to a remote dumping point. They combine these two functions in a single machine, nearly always in a single straight-line motion. [ ] The purpose of this paper is to examine the important features that distinguish the machines in this group from each other, as well as from other groups. The Machines The "power drag scraper" is a long-range excavating machine that employs a bottomless drag scraper operated back and forth between digging and dumping points by two haulage cables. The typical arrangement is that of Fig. 1. This is the "slusher" of the underground mine, as well as the "dragline scraper" of the sand and gravel industry, and other open-pit mining operations.

Jan 1, 1937

By Harry Roeser

Short cuts for determining the constants of oil decline curves, with the method of least squares as a starting point, are presented and applications made to practical examples. The nature of the raw data does not justify rigid adherence to the orthodox theory but does lend justification to convenient methods of approximation within reasonable limits. If the conventional form y = kxn were changed to y = k(x + c)', methods of determining the curves would be simplified and greater uniformity in calculated results would probably follow. As A result of the publication, several years ago, of some articles on determining the constants of empirical formulas, the determining the constant's of types of curves used for estimating the production decline of oil wells was brought to the writer for study. Methods requiring a minimum of time and labor and a maximum of rigor were sought, as it appeared that the nature of the data from which such curves are computed and the relative uncertainty of occurrence of the events predicted from them did not justify close adherence to the theory on which the solution of such problems is ordinarily based. The technical deficiencies of the solutions presented in this paper, from the standpoint of the method of least squares, are readily apparent to those familiar with that method, but their presentation in detail here is irrelevant to the subject matter. However, it is the author's conviction, after a rather exhaustive study of the problem, that the value of the solutions lose little by the approximate application of the conventional theory. It must be understood by those who use these formulas that the solutions herein given, and the formulas based on them, are merely facilities to aid the valuation engineer in forecasting future events. It is assumed, also, that before application is made of them, prescient judgment based on the circumstances in each case, shows that the forecast has some probability of realization. On this basis only will these formulas be found useful.

Jan 6, 1924

By E. J. McKee

THE area discussed lies south of Canadian River in Hutchinson County, Texas, covering approximately 10 m. east and west and 4 m. north and south. Development is carried on in the manner usual in standard tool operations. No outstanding divergence from the usual methods is necessary as wells are completed in 35 to 55 days to approximately 3000 ft. Most of the time is lost in the upper part of the hole and is usually caused in driving pipe of larger sizes. After approximately 1500 ft., little trouble occurs. A comparison of 13 contractors drilling for Phillips Petroleum Co. gave the following averages: Drilling time from 32 to 63 days with a daily footage of from 49 to 87 ft. per day. The rigs furnished are National turnbuckle type with 6-in. irons and steel wheels.

Jan 11, 1926

By H. K. Work

THE instrument for the rapid determination of carbon in steel, described in this paper, was developed originally to facilitate the opera-tion of the pilot-sized open-hearth furnace in the Jones & Laughlin Research and Development Laboratory. In this small furnace, with its shallow bath, the drop in carbon is accelerated, and a rapid, reliable test for carbon content is indispensable. This problem becomes rather acute when it is desired to finish heats at a carbon content higher than can be estimated with any degree of accuracy by the fracture test. Several independent methods for determining carbon were investigated, therefore, and it was found that a relatively simple magnetic device could be made to give reproducible results. A laboratory instrument was designed and set up for the use of the furnace operators. It was tested exhaustively in the laboratory and was used with considerable success for following the carbon content in the furnace bath. As soon as suffi-cient data had been compiled to indicate that the instrument might have a wider application, a more rugged model was constructed and placed in the mill to be tested on commercial heats. Finally, about a year ago, instruments were furnished to the plant open-hearth shops, and these have been in use since that time. As a matter of convenience, the instrument has been named the "Carbanalyzer," and will be referred to by this designation in the following pages. ?

Jan 1, 1939

By L. A. Pursell

Environmental constraints can both delay and raise the cost of a major plant addition, often requiring a complete reevaluation of the plant site and the proposed project. In this case history, steps are presented which were followed in applying for environmental permits for a major addition to a lime plant. Methods are described for determining expected emission increases and for selecting the best control technology for each source. The description progresses through pre-application conferences with control agencies, the formal application procedure, computer modeling the air quality impact, and the methods followed in obtaining a favorable determination.

Jan 1, 1983

By O. W. Walvoord

To those working in the mineral industry, the flowsheet is a familiar and valuable tool, seldom used, unfortunately, to its fullest advantage. As with so many other commonplace and simple items, there is little or no attempt to expand on the forms, and types of flowsheets. A flowsheet or flow diagram may be defined as an illustration showing circulation of the ore stream in a concentrating plant. It may be further described as an explanatory graphic design or picture. A flowsheet is obtained by interpreting the metallurgists' research and ore test data, usually with some adjustments to suit the economies of the project. It brings together, in compact form, information from a number of sources.

Oct 1, 1956