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By Pieter W. Greeff, Graeme W. Mitchell

INTRODUCTION This paper describes the underground environmental planning parameters developed for Pancontinental Mining Limited's Jabiluka uranium deposit. The deposit is located 230 km east of Darwin in the Alligator Rivers region of the Northern Territory, Australia. The deposit is situated within land subject to an Aboriginal land claim, adjacent to a National Park and within a proposed extension to that National Park, as well as being close to a long- established Aboriginal reserve. In addition, being the first large underground uranium mine planned in Australia, the environmental considerations, both on surface and underground are considerable. Pancontinental is committed to the highest practicable standard of environmental management in the operation of the mine. In addition, Government regulations and requirements are particularly stringent by world standards. The underground environmental problems are discussed later in the paper with emphasis placed upon radiation aspects, both gamma and radon daughters, and dust. Consideration has also been given to heat and humidity due to the location of the deposit in a sub-tropical region 12° south of the equator. The paper explains how these environmental factors influence the design and selection of stoping methods. GEOLOGY AND ORE RESERVES The Jabiluka Two orebody is completely overlain by flat-bedded Kombolgie Sandstone with a thin layer of surficial colluvial sands. The orebody occurs in an east-west striking folded succession of Lower Proterozoic metasedimentary rocks of the Cahill Formation. Uraninite and pitchblende constitute essentially all the uranium mineralisation and are contained in the four lithological series, as shown in Fig. 1. - ,Upper Graphite Series - Main Mine Series - Lower Mine Series 1 - Lower Mine Series 2 The succession at Jabiluka has been folded and forms an east-south-east striking, asymmetric syncline-anticline which dips south and plunges to the east. A major fault bisects Jabiluka Tw8 having a north-south trend and dipping about 80 to the west. A near vertical tourmaline granitic pegmatite dyke up to 30 m in thickness has intruded the Jabiluka Two orebody at the western end. Current drilled ore reserves for Jabiluka Two are 52.0 million tonnes at 0.39% U308. Included in these reserves are 1.1 million tonnes of gold ore at 10.7 g/tonne. A large proportion of the orebody can be mined in thick sections (over 80% of tonnage) either as single sections or by bulking a number of thin sections which are close together.

Jan 1, 1981

By H. M. Rutherford

THE reflection method in seismic prospecting has aroused much interest in the past few years. The purpose of the present paper is .to present the method of reflections in the mapping of geologic structure and also to give some indication of its limitations. The reflection method is well adapted to the mapping of geologic structure in the Mid-Continent fields, and has been found most useful there. The refraction method is ideally suited to the finding of structures, such as domes, where the amount of relief is very large. This explains the brilliant success of the refraction method in the Gulf Coastal region of Texas and Louisiana. The additional fact that salt has a much higher velocity than the sur-rounding sediments made their discovery much easier. By the use of the reflection method, differences of relief of 25 to 50 ft. to the mile may be detected at a depth of 5000 ft., and the depth points accurately plotted on a map. This is hardly possible by the use of the refraction method. The reflection method has been in almost continuous use in the Mid-Continent area since 1926, but very little, if anything, has been published until recently(7) ? regarding either the method or the results. The dis-covery of several oil fields is now attributed to the use of the reflec-tion method. Reflection methods have been used by the Germans to find the thick-ness of the ice of several glaciers. (2,8) The depths there considered were of the order of only a few hundred feet. For the method to be of any practical value in this country, it must be able to work to depths of several thousand feet. As was indicated above, this is now possible, though there are many problems connected with the reflection method yet to be solved. The refraction method requires that the shooting be done over long ranges. It was necessary, for example, to take distances out to several miles in order to penetrate some five thousand feet. Naturally this uses a good deal of dynamite. In the reflection method the distances are much shorter and the amounts of dynamite are much smaller, within limits which will be noted below. The chief distinction between refrac-tion and reflection methods is to be found in the analysis of the seismo-gram. Refraction shooting makes use of only the first arrival of energy

Jan 1, 1932

By C. R. Fondersmith, John Chipman

In the manufacture of rimming steel—which constitutes the bulk of the world's production of mild steel—the factors that determine the quality of the product are very closely associated with the pouring and solidification of the steel in the ingot mold. The behavior of the metal in the mold is, on the one hand, the resultant of the complex processes through which the liquid metal has passed, and, on the other, it is an indication of the probable behavior of the ingot during subsequent rolling and finishing operations. A detailed study of the mechanism of solidification of rimming ingots ought to yield information that will be useful in controlling the structure of the ingot and the quality of the ultimate product. The first step in such a study is to determine the rate at which the solid shell of the ingot forms from the liquid metal in the mold. A knowledge of the rate of solidification will make it possible to correlate observations of rimming action and gas evolution with studies of the structure, porosity, and segregation within the ingot. Thus, if the metal in the mold is observed to fall, let us say one minute after pouring, the portion of the structure associated with this fall will be located in the part of the ingot that is solidifying at that particular moment. The knowledge that the ingot solidifies to a depth of 3/4 in. in the first minute enables us to locate in the ingot the structural features corresponding to the observed fall. Conversely, the blowhole condition associated with a rising or growing ingot will be found in the part of the ingot that is solidifying at the time the phenomenon occurs. The time required for the complete solidification of an ingot has long been a matter of speculation. It is of considerable practical importance in connection with charging and heating in the soaking pits. Too rapid handling of the ingot through heating and rolling processes has been thought to be associated with excessive pipe and other internal defects, so that a further object of this investigation was to attempt to estimate the time required for complete solidification, or the minimum practical time within which the subsequent operations can be performed with the minimum hazard.

Jan 1, 1937

The apparent small effect of skimming on desulphurization is somewhat misleading because the data was collected during the first months of use on the skimmer. During this period of time, the operators were, of course, just learning to use the equipment and, consequently, in many cases a so-called skimmed heat may have only been partially skimmed. In addition, during this period, the percentage of sulphur in the blast furnace slag was gradually increasing because of the increasing oil injection rates being employed at the blast furnace. An additional factor that cannot be disregarded is the apparent slower slag formation rate obtained in the BOF when the blast furnace slag is removed. This is evidenced at our shop by a much stronger tendency toward sparking and related lance skulling problems with deslagging, in spite of satisfactory manganese levels in the hot metal. Naturally, slower slag formation could account for poor desulphurization which would partially offset the beneficial effect of a lower sulphur input.

Jan 1, 1972

ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members) Graduate mining and metallurgical engineer now open for engagement. Member, 38 years old, married, 19 years' experience in United States, Europe, South America, Africa, in exploration work, surveying, assaying, mining, milling, ore-dressing, construction and management. Four languages mastered. No. 355. Member, aged 35, technical graduate, desires position -as superintendent or assistant superintendent of spelter or zinc oxide furnaces, or both. Gas producer experience, zinc metallurgical and laboratory experience. Can handle men. No. 356. Member, also Assoc. Mem. Am. Soc. of C. E.; excellent technical education, and best of references covering twelve years in responsible charge of work; experienced in surveys, construction, prospecting, mine examination and development and irrigation work; speak Spanish fluently, and can write a good report. Good executive. Available during June. Age 34; married. No. 357.

Jan 6, 1917

By F. R. Van Horn

WALLACE MCKEEHAN, Douglas, Ariz. (communication to the Secretary*).-In going over this report, which I have done very carefully, I find that the summary as composed deals with the various problems almost entirely from the employer's standpoint and that practically no consideration is given to the employee's point of view. An experience of 3 ½ years as safety inspector, and almost 30 years as workman-and official, has convinced me that any plan for the betterment of working conditions which will achieve any degree of success must give the workmen their share of responsibility and allow them full participation. The company may finance and direct the movement, but its ultimate success depends upon the support given by the workmen. The cooperation of the men doing the actual work is so essential that all writers insist that this must be secured, but they do not agree as to how this can best be done.

Jan 4, 1917

Florida State Geological Survey, Tallahassee, Fla Herman Gunter, State Geologist A list of publications will be sent upon request Citizens of the state may obtain publications available without cost, others may have them for postage, or they can be sent express collect Twenty Annual Reports have been issued from 1908 up to and including the 21st-22nd Annual Report (1931). Only three are now available; 4th Annual Report (1912), 15th (1924) and 18th (1927) Reports since 1921 contain statistics on mineral production. All reports contain papers on various subjects, many of which are still available separately, and are so indicated in the list of publications. Seven bulletins have also been issued, principally of interest to paleontologists Bulletin 7, The Pensacola terrace and associated beaches and bars in Florida (1931), is of more general interest Bulletins will be sent upon receipt of postage. Thirteen Press Bulletins, most of which are available, have also been issued, but are of minor interest

Jan 1, 1933

I HAVE hitherto shown you as well as I knew how the procedure for those operations which are needed in melting on either a large or small scale, as you might need them. Now I wish to pass on to some other operations which, while related to the operations and power of fires and also to certain kinds of melting, are not wholly connected with the art of casting. First I wish to begin with the actual substance of the art of alchemy, which is sought and desired with so much zeal. Then, as a useful and ingenious thing, I wish to inform you of the art of distilling, and, afterwards, how you should operate a mint in an orderly fashion and without burden on the conscience. Then I shall tell you of the ironworker, the goldsmith, the coppersmith, and some others, as you will be able to see in their places.

Jan 1, 1942

The Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and outstanding attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The following were the Howe lectures and lecturers for the years indicated 1924 What is Steel? By Albert Sauveur. 1925 Austenite and Austenitic Steels. By John A. Mathews. 1926 Twenty-five Years of Metallography. By William Campbell. 1927 Alloy Steels. By Bradley Stoughton. 1928 Significance of the Simple Steel Analysis. By Harry D. Hibbard. 1929 Studies of Hadfield's Manganese Steel with the High-power Microscope. By John Howe Hall. 1930 The Future of the American Iron and Steel Industry. By Zay Jeffries. 1931 On the Art of Metallography. By Francis F. Lucas.

Jan 1, 1923

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, graduate Columbia School of Mines, age 35, married, best of health, dependable, desires position as manager or scout for reliable interests. Experience covers responsible positions incident to the mining and milling of gold-silver, copper, lead, and zinc ores, and the examination of base and rare-metal deposits in United States and Mexico. Salary $3600. Available April 1. No. 453. Member, mining engineer, technical training, age 32, assayer, engineer and superintendent of porphyry copper development, churn drilling and shaft sinking. Examination of prospects and development of gold prospects. Considerable flotation experience. No. 454. Young Columbia graduate, conscientious worker, with experience in inorganic analysis, surveying, draughting, and wit. post-graduate training in geology, desires position wt. prospects. Minimum salary considered, $130 in U. S. and $150 in Mexico. At present employed. Draft exempt. No. 455.

Jan 5, 1918

By J. P. Zannaras

If we assume that testing of the model started at time C, that time t2 was the instant at which the elastic limit of the material was passed at the points of the maximum stress, and that at time t3 the failure of the model was completed as shown in the typical photograph (Fig. 1), then actually the photograph shows the final results of what took place between time t2 and t3. By the principle of similitude all conclusions drawn from the behavior of the model were applicable and valid for actual mine roofs up to the time t, after time t, motions and friction came into play during the destruction of the model. The events between t2 and t3 and the photograph itself are not representative of the events expected in an actual mine roof unless corrections imposed by the principle of similitude are made.

Dec 1, 1956

By Freeman Bishop

President Allende says he will expropriate all American investments in Chile and he's already well on the way to accomplishing this objective. What the average observer doesn't realize is that this has not only created big lossess for the copper companies. It could also take a chunk out of the U.S. taxpayers' pockets. Premier Castro expropriated the U.S. taxpayers' investment of over $100 million in the Nicaro (Cuba) nickel and cobalt operations-and U.S. Government protest over the loss was never heard above a whisper. Where the taxpayer comes in today is through the Overseas Private Investment Corporation, which was set up to guarantee U.S. companies' foreign investments against losses due to political changes. As of now, metals firms hold more than $300 million worth of obligations against this U.S. Government agency. The agency itself may not be able to raise more than $85 million, and a supplemental appropriation may be needed to meet its guarantees.

Jan 1, 1971

This Association is made up of Alabama members of the following technical societies: The American Society of Civil Engineers, American Institute of Mining Engineers, American Society of Mechanical Engineers, American Institute of Electrical. Engineers, American Chemical Society and the American Institute of Architects. The association organized last winter for the purpose of maintaining an organization among the technical men of the State of Alabama, to stimulate the development of the natural resources of the State, to foster public interest in all things beneficial to the State, to advance the interest of the technical profession in the State and to encourage social intercourse among its members. On June 30, 1917, an excursion was made to the power house of the Alabama Power Co. at Lock 12 on the Coosa River. This is the first meeting held outside of Birmingham and is also the first meeting to which ladies were invited. About 85 members and guests attended and the excursion was voted a great success by all present.

Jan 8, 1917

By Allen R. Rowen

One of the greatest deterrents to more widespread use of manufactured lightweight aggregate is the fact that no industry-wide standards for its application exist. It is true that ASTM has specifications covering lightweight aggregate, but they are so broad as to be of little assistance in mix design work. Today even an engineer who has worked with one lightweight aggregate may be faced with re-education on his next light- weight concrete job if he is in an area served by another producer. Manufacture of lightweight aggregates has grown with the country, appearing in the patent literature at least as early as 1875, when a patent was issued covering use of burnt clay aggregate as an admixture in manufacture of artificial stone. The widely known Haydite came into the picture prior to 1920 as a result of work by Stephen J. Hayde, and there have been many others since who have contributed significantly to the growth of the industry and its technology.

Nov 1, 1956

By Roswell Johnson

A CANVASS of the various institutions known or suspected to be giving courses dealing with petroleum and gas revealed the courses listed in the accompanying table, which includes a summary of the number of class hours, as a whole, of the courses listed. It will be observed that the situation is grati-fying. Courses are presented in different institutions in the main geographic sections of the country, so that students have no difficulty in obtaining education in this field. The committee believes that the courses that are offered in many institutions are so inadequate in amount as to make it unwise for students who have not had additional work to consider themselves trained in this field. We strongly urge the few schools now presenting the most adequate courses to develop these more fully, bringing their work up at least to 300 hours, and let other schools concentrate their energies in other fields.

Jan 6, 1922

POSITIONS VACANT (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Wanted for a mill on the Ivory Coast of Africa an experienced amalgamator and millman. Salary, $160 to $200 per month. No. 18. ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Chemist-metallurgist of broad technical training, university graduate, with experience in chemical and metallurgical research work, desires position, preferably in the East. Has successful past that stands investigation. No. 73. Member, mining and metallurgical engineer; thorough technical training, Ph.D., Columbia University, aged 39, married, with-an-extensive experience in smelting, mining, and economic geological work in U. S., Mexico, and South America, desires position as assistant to the Manager or Superintendent, or as a director of experimental and research work, with a reliable mining or metallurgical company. The West, Mexico, or South America preferred. No. 98.

Jan 6, 1914

By Antonio Marrano, Eda F. Quadros, Diogo Correa [Fo], Paulo T. Cruz

For many years the water pressure test has been used as a normal procedure to investigate the hydraulic characteristics of rock masses and discontinuities. Although the test has given evidence of problematic areas, the nature of flow and the so called equivalent permeability are seldom seriously affected by the testing tecnique. In order to improve the information on these points the Instituto de Pesquisas Tecnológicas de São Paulo - IPT, has developed an extensive program at laboratory and field research on the hydraulics at rock fractures. This paper summarizes the main items related to this research. Is shows that with only small improvements on field tests and some support of laboratory conductivity tests on natural rock joints it is possible to obtain a better understanding of the nature of flow in fractures, improve flow predictions and estimate the opening and hydraulic conductivity, as well as the transmissivity of natural joints or rock discontinuities.

Jan 1, 1982

By R. S. Shrode, R. F. Bunting

Transportation is one of several important increments in the total market cost of most commodities. On a national average it has been reported that transportation accounts for about 25% of the total cost of a product at the market place. And industrial minerals are no exception. In fact, the proportionate cost frequently exceeds the 25% average. Further, it may actually determine the economic value of a deposit. Transportation possibly may be thought of as a specialized subject, of concern only to a traffic manager and of only nominal interest to the mining engineer, the geologist or other technically oriented member of a mineral producers' staff. However, in the industrial minerals field, interest is not commonly confined to exploration, development, production or marketing, but is in contrast an overlapping one. In a very real sense this broad area of interest in the total economics of the business is the specialty of the industrial minerals man. And transportation is a vital part of the total picture.

Jan 1, 1970

By R. W. Smith

A study has been made of the crushing and grinding circuits by the Portland Cement Association in nine cement plants. Five of the plants used the wet process and four, the dry method. Both raw and clinker grinding were studied in the four dry processing plants. The raw materials used varied considerably from plant to plant. Actual power consumption data were obtained for the majority of the grinding mills in these plants. Previously representative raw and clinker samples had been obtained from the nine plants, and Bond1 and Hardgrove2 grindability tests were run on these samples. All pertinent data concerning the grinding mills, such as mill size and speed, ball charge size and weight, size distribution of feed, and discharge materials were also obtained. Thus it became possible to calculate the actual horsepower used by the various mills, and to compare this figure to the theoretical horsepower as calculated by several different methods.

Jan 4, 1961

By Wayne E. Hall

The Darwin mining district of California, 160 miles north of Los Angeles, has yielded an estimated $45 million in lead, silver, zinc, and copper since 1875. The deposits are in silicated limestone of Pennsylvanian and Permian age close to a stock of horn- blende-biotite-quartz monzonite. Steep left-lateral strike-slip faults that strike N 50" 70" E served as feeder channels for the ore solutions, and minor folds, favorable beds, and faults close to the feeder channels localized the orebodies. The orebodies are irregular, steep, pipe-like replacements that cut across bedding, bedding replacements, and fissure fillings in a calc-silicate country rock consisting mainly of wollastonite, grossularite-andradite garnet, idocrase, and diopside. Near surface the ore consists of a soft, crumbly mass of cerussite, hemimorphite, jarosite, limonite, and some secondary copper minerals. The primary ore consists of galena, sphalerite, pyrite, pyrrhotite, and chalcopyrite with smaller amounts of andorite, matildite, scheelite, tetrahedrite, and a high silver- lead-bismuth-selenium-bearing galena.

Jan 9, 1959