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By R. T. Carter

THE phase behavior of a number of binary systems consisting of paraffin hydro-carbons has been determined in recent years. In addition, the composition of the coexisting phases of mixtures of crude oil and natural gas has been investigated.1 However, the latter study did not include information concerning the influence of the concentration of a component upon its distribution between two coexisting phases. Owing to the paucity of such information it was considered desirable to investigate in some detail the composition of the co-existing phases in the methane-propane-n-pentane system throughout the greater part of the two-phase region at a tempera-ture of 100°F. Information of this nature also permits the establishment of the critical behavior of this ternary system.

Jan 1, 1940

By E. W. Codington

The pebble-phosphates of Florida occur in a district roughly bounded on the north by the 28th parallel, on the east by an irregular line running a few miles east of Peace river and on the west by the Gulf of Mexico, and covering an area of about 4000 square miles. There seems to be no reason why the deposits should not extend farther south along the gulf coast. That section remains unprospected, transportation-facilities being non-existent. It is not intended in this paper to discuss the geology of these formations; but a word as to their probable origin will be perhaps the best method of giving a correct idea of their present position. Starting with a low, flat surface, with even less of superficial undulation than appears at present, an im-

Jan 1, 1896

By Eugene P. Pfleider

RECENT interest in germanium centers around its use as a semi-conductor of electricity in electronic devices. It is generally believed that germanium transistors, diodes, triodes, photocells, and rectifiers will largely replace the present-day vacuum tubes. The germanium electronic devices are much smaller, lighter, and more resistant to shock, and they require only a small fraction of current required for conventional devices. Hence only a small amount of heat is given off by the equipment. This development will require many times the quantity of germanium now being produced, which in 1948 was approximately 1000 lb' and was obtained almost entirely from zinc ores in Missouri, Kansas, and Oklahoma. No one knows with certainty what the demand will be for ger-manium by 1956. It may be 40,000 lb.1 Known concentrations in zinc ores are not sufficient to

Jan 1, 1954

By J. B. Newsom

IN the Indiana limestone district, some 50 or 60 per, cent of the merchantable stone in a quarry opening is waste, and only about 40 or 50 per cent of the stone from the opening is finally sold. So long as the present system of quarrying is used, the wastes measured and reported in this paper will continue. Comprehensive development of an entirely different method of quarrying, using wire saws for cutting, promises great improvement. Some of the savings to be expected are pointed out in the following pages. No attempt has been made to measure losses due to variations and natural flaws in the stone, since these vary greatly in different quarries, and accurate measurement would be difficult. The wastes that have been measured account for about 30 per cent of the total ledge, which leaves 20 or 30 per cent chargeable to unmeasured sources of loss.

Jan 1, 1932

Jan 1, 1936

By Gee C. E

Ore reserves at the Kambalda Nickel Operations of Western Mining Corporation are estimated using the polygonal method for calculating areas of influence of drillholes. All raw assay and survey data are stored on one disk pack on the Company's CYBER 73 computer located in Perth, about 600 km from Kambalda. The initial step involving the computer is to search all assay data and calculate all potential ore-grade intersections. As the orebodies are thin, structurally complex and many are in close stratigraphic proximity, the selection of intersections which have the best grade over at least a minimum mining width involves complex logic. The orientation of an ore surface at each drill intersection point and a zone code are added to each intersection by the geologist from geological plans prepared for each ore surface. The orientation data together with downhole surveys enables the calculation of inter- section true widths and the zone code links each recalculated intersection to the appropriate ore surface.

Jan 1, 1977

By Kenneth S. Graham, S. C. Gambrell

A short term, simple roof bolt load cell which uses a birefringent (photoelastic) coating as its sensing element has been developed. The load cell is installed between the bearing plate and the nut/washer and measures the initial force after installation by the bolting machine. The load cell can be removed from the bolt and used again to measure initial force in another bolt if desired. Because temperature and humidity changes in the mine cause creep/relaxation of the coating and/or adhesive, the load cell is useful for accurately measuring force for a period of only two weeks after installation. Force in the bolt is determined by referring to a calibration curve for the load cell.

Jan 1, 1992

By S. S. Peng, V. Z. Sun

One of the major concerns of ground control in a coal mine is the prevention of roof, pillar and floor failures of the mine entry. To better design and evaluate the stability of a mine entry within a certain level of confidence, a reliability approach is introduced. The advantage of using the reliability approach, rather than the conventional safety-factor (SF) method, is that it not only takes variability of both rock/coal properties and stress into consideration but also assesses the stability of each component and the mine entry as a whole. Therefore, it is anticipated that by using this approach the current ground-control technology in a coal mine will convey a better sense of confidence. The results of a case study show that there is a significant difference in mine entry stability between the current design method and the reliability approach.

Jan 1, 1999

THE first award of the James Douglas gold medal for achievement in non-ferrous metallurgy was made to Frederick Laist, of the Anaconda Copper Mining Co., and the presentation ceremony was a feature of the annual banquet of the Institute at the Waldorf, on Feb. 21. Frederick Laist was born in Cincinnati, Ohio, Oct. 30, 1878. In his early youth his parents moved to California where, in 1901, Mr. Laist graduated from the University of California, in the course of chemical en-gineering. For one year after graduation he was an in-structor in chemistry at the University of Utah. Fol-lowing this he was employed as a chemist in the lab-oratory of the Washoe Reduction Works of the Anaconda Copper Mining Co., where in successive stages he has occupied the position of chief chemist, blast-furnace superintend-ent, assistant superintend-ent of the entire plant, superintendent, and finally manager of the Anaconda company's reduction plants in Montana, which position he now holds. Mr. Laist, in his labora-tory work, manifested great interest in the hydrometal-lurgy of copper and zinc. As chief chemist at Anaconda, he brought the laboratory to a high degree of efficiency.

Jan 3, 1923

By B Shen

The Wambo Rail Spur located near Singleton, New South Wales, Australia, runs for approximately 14 km linking the Mt Thorley rail loop and the Wambo Coal Mine. The project involves a 260 m long tunnel in weathered sedimentary and intrusive materials. The tunnel has a low cover and runs under a main highway. This second paper on the project looks into one aspect of the tunnel in detail: the use of shotcrete arch as the primary support for part of the tunnel excavation. The use of shotcrete instead of steel arch, formulation of the material specification, construction sequencing, installation at the excavated face and material testing for verification related to this facet of the project will be discussed in this paper. The tunnel opened in April 2006, and two years on, we briefly reflect on the impact of this design decision on the overall project.

Jan 1, 2008

By Wei Wu

A computer-aided method for optimization of bench blast design in surface mines is presented. The design procedures basically consist of two steps. Firstly, a series of normalized, full- scale bench crater tests must be carried out in the field to find the optimum burden that produces the largest amount of acceptable fragments and other parameters that defines the effective fracture zone. Next, the locations and initiation sequence of blast-holes will be determined in such a way that each hole, at its time of firing, will be responsible for same amount of burden rock and will be in a position favorable to effective fracture of burden rock. A computer software "B.B." which can assist the second step of the design is fully introduced and its application is illustrated by an example.

Jan 1, 1992

By R. H. Frank

IN the investigation of the effect of the time of heat on slag volume, no attempt was made to vary the usual practice at the Bonney-Floyd Co., such as selecting special-purchase scrap or cleaning foundry returns. The data were collected from seven normal heats, including four medium carbon, two medium manganese-molybdenum and one nickel-chrome-molybdenum. These heats were made with our normal practice and no special instructions were given the melters except to make sure that all slag-making materials were weighed and that no slag was lost during the melting, refining or tapping. After the stopper was set in the ladle, it was carefully weighed and the heat was tapped. As soon as the heat was slagged on the pouring floor, the nozzle was plugged with mud, to preclude the possibility of losing any slag while the ladle was being conveyed to the scales. The ladle, containing all of the slag, was weighed and the difference between this weight and the original weight was taken as the slag weight.

Jan 1, 1947

By T. Taniguchi

The existing Mitsubishi Process line at Naoshima Smelter and Refinery has been operating successfully since 1991, and its present production capacity is 270,000tpy of copper. Furnace relining works have been carried out every two years to coincide with the compulsory bi-yearly boiler inspection, but the next target is to extend the furnace refractory life to four years, while still undergoing the mandatory boiler inspection every two years. Although the damage of hearth bricks beneath lances in the Smelting furnace was a matter of concern, it was reduced by controlling gas velocity and evening solid distribution to each lance. The life of bath level bricks in the Converting furnace was also a concern, but four-years continuous use of the bricks was achieved in the course of the last two campaigns. Several other improvements were also carried out to the cooling systems during the shutdown in 2005 to ensure longer campaign life. This paper summarizes recent improvements implemented to enhance the advantages of the Mitsubishi Process.

Jan 1, 2006

By George H. Cook

At first sight this subject seems to belong to pure theoretical geology, but examination will soon show that it has important practical and economic interest to the mining engineer. The conclusion that all the northern portions of our country, as well as of the eastern continent, have, in the later periods of geological history, been covered with a thick bed of ice, is now accepted by geologists. This bed of ice, except in its greater magnitude, was like the modern glaciers of the Alps, and other mountains which extend above the line of perpetual snow. The marks it has left upon the surface show that it was comparatively thin on its southern edge, but that its thickness was much greater a little further north, and that it was several thousand feet thick at its kenviest parts. This variation of its surface would give it a descending slope towards the south, and cause the mass of ice, like a semifluid substance, to move in that direction,

Jan 1, 1879

By Pierre-Yves Morvan

One of the numerous challenge for underwater mining is the positioning. This paper describes an architecture for the integration of an Ultra Short BaseLine (USBL), an Acoustic Synthetic BaseLine (ASBL) operating in Sparse Array mode and a Doppler Velocity Log (DVL) closely coupled with an Inertial Navigation System (INS) for precise subsea positioning in severe environments. By using such architectures, the INS can help to reduce the noise on the measurements coming from acoustic sensors. Another advantage is the capability to reduce the number of required transponders on the seabed, and as a consequence, reduce the time for the deployment and calibration of each transponder. The paper further describes sea-trials performed to assess the ability of a complete positioning system to provide decimetric positioning precision even with a single beacon deployed in the navigation area.

Jan 1, 2017

By R. S. Dean

AMONG naturally occurring inorganic compounds, magnetite has many unusual and interesting properties, and it is the purpose of this paper to call attention to these properties and review possible uses of magnetite that might be based on them; in other words, to see what uses may be found for magnetite as a physical rather than as a chemical entity, as a mineral rather than as an iron ore. The Mineral Physics Studies initiated in the Metallurgical Division of the U. S. Bureau of Mines a few years ago gathered together much information on mineral properties, and they are therefore the principal source of material for this paper.

Jan 1, 1937

By Thomas Fenner

Surface and underground mining operations are often hindered by unknown tunnels and slopes and the precise locations of adjacent workings. Mine safety and planning are adversely affected especially in previously undermined areas where historical records are incomplete or nonexistent. The results of several ground penetrating radar (GPR) studies for the detection of known mine tunnels in underground coal, salt and gold mines are presented. A case study to locate unknown, abandoned mine workings at a surface gold mine successfully located all workings to a depth of 11 m (36 ft).

Jan 1, 1996

THE auriferous sulphide ores of the eastern end of Gippsland, and notably of the Cassilis and lVIitta districts, are amongst the most complex and refractory in Victoria-perhaps in Australia. The minerals occurring in these ores are pyrite, arseno-pyrite, zincblende, galena, and (in smaller amounts) some of the copper, sulphides, as chalcopyrite and covellite; and some of the antimonial minerals, notably stibnite and jamiesonite. In the oxidized portions of the lodes, the oxidized lead and iron minerals, and small amounts of the hydrated arseriiate of iron, are found.In the Cassilis mine, near Omeo, copper is present usually in quantities of under 1 %. The magnetic sulphide of iron is of fairly common occurrence. In, the upper levels of the Cassilis mine tin was usually present, the amount going up to 3% in some samples of concentrates. These minerals occur sometimes banded, but usually as an intimate mixture-pyrite and arseno-pyrite predominating. The gangue is usually quartz (blackened by enclosed particles of sulphides). Calcite, magnesium silicate and felspar are also present in varying amounts.

Jan 1, 1911

By W. P. Blacutt

A financial-economic model incorporating physical, market and policy variables has been developed for mining investment in Bolivia. Additional risk criteria emanating from political instability, new mining legislation, recent environmental regulations and a new minerals taxation system are accounted for and are integrated into the investment decision model. Results of the model indicate that geologic and market variables have the dominant effect on the investment-worth function. Among policy variables, exchange rate and taxation policies have the most significant influence. Depreciation allowance for infrastructure development has negligible weight in the investment-worth function. The business structure of the firm considering investing in the Bolivian Polymetallic Project, is found to be an instrumental factor in the investment-worth outcome.

Jan 1, 1995

By Jon C. Yingling

Techniques for optimization of mineral processing flowsheets are reviewed. Though not yet widely used in the minerals industry, approaches for chemical process optimization based on successive quadratic programming (SQP) algorithms may be employed to determine optimum unit design and control settings for a mineral processing flowsheet. Moreover, in certain mineral processing flowsheet applications, specialized techniques can be applied because of the nature of the system relations. These techniques offer advanta es in efficiency. Moreover, their capability exceeds that o f the SQP approaches since simultaneous optimization of circuit configuration and unit controls can be addressed.

Jan 1, 1990