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DEPENDENCY on foreign sources for many mineral raw materials is a characteristic of our economy which is becoming painfully evident. Although investment in foreign mining projects has increased, it has not kept up with the growing demand for foreign minerals. The sphere of American investment capital in mining ventures abroad has been severely limited by the rise of nationalism in many underdeveloped countries. Consequently, we can look back over half a century in which mining investment, exclusive of petroleum, has increased by 50 pct whereas other American investments abroad have multiplied by better than 300 pct. Investment in foreign mining or petroleum encounters different problems than capital investment for other industries. It is rarely invested in industrialized nations. Most of it goes to countries with expanding frontiers, like Canada, or to underdeveloped nations like Liberia. It must be used for building communities, recruiting and training labor, and establishing lines of communication and transportation. These complications are an accepted part of the mining game. However, the most complex problem is in those countries which consider mineral exploitation a usurpation of the people's natural heritage. This is a characteristic of the young government existing by a tenuous balance of power in an underdeveloped nation. American mining capital understandably has shunned these nations as being poor investment risks. However, they possess minerals which are needed by industry. Our government has attempted to stimulate mineral supplies beyond those provided from abroad by private capital. ECA, now under DMPA, makes loans to foreign mining companies. Since the ECA program cannot be expected to continue indefinitely, Point IV seems to be the logical next step to encourage foreign countries to fill our shortages. However, only 1 pct of the $35 million budget provided in the first year for Point IV was alloted for mining programs. Considering the need for minerals and the difficulties of procuring them by private investment, a larger share is needed and justifiable. Those who have been engaged in foreign mining can vouch for the fact that it takes many decades to teach the complex technology and economics of mining to the natives of under-developed countries. For this reason Point IV must be considered a long range program. Mineral requirements for the present must be met by more direct measures. Encouragement of private investment in foreign mining by such incentives as tax relief on profits from foreign sources, international bank-borrowing facilities for private capital, and diplomatic assistance in encouraging foreign countries to cooperate are imperative for our future mineral security.

Jan 1, 1952

An experiment substituting pneumatic crawler drills for large-diameter rotary rigs in overburden stripping operations has indicated significant bit cost savings for Perry and Hylton Coal Co., Beckley, W. Va. The test was conducted in the Egeria Mountains (part of the Appalachian Range), where about 30 m (100 ft) of overburden consisting of hard, seamy sandstone and shale must be removed to recover a 560-mm (22-in.) vein. Perry and Hylton operates ten surface mines and is presently developing three more for start-up in the near future. The company follows a progressive policy toward ecological concerns, incorporating a self-imposed systematic mining and reclamation program for mined lands which leaves the landscape in a suitable condition for further development by local communities.

Jan 6, 1976

By G. K. Burgess

J. W. RICHARDS, South Bethlehem, Pa.-I think my affections are still rather with the radiation pyrometer than the optical pyrometer, for practical use, and I wish that Prof. Burgess would use the two together, under the same conditions, using the optical as his standard, if he prefers. Then, assuming the optical emissivity which he feels is correct for the optical pyrometer, he could calculate the thermal emissivity for use with .the radiation pyrometer. If we could thus get reliable values for the thermal emissivity, we could then use the radiation pyrometer, and would avoid the use of the standard lamp, which has to be frequently calibrated for use in the optical pyrometer. It is very advisable to distinguish carefully between the terms optical emissivity and thermal emissivity. There -is considerable confusion caused by the bare statement that molten iron has an emissivity of so much, meaning by that its optical emissivity, for a light wave of a certain length; whereas what we want in the radiation pyrometer is its total ther-

Jan 4, 1917

By F. P. Agterberg

It can be useful to model the mean grade values for a metal in mineral deposits containing that metal as representing the extreme value tail of a lognormal frequency distribution for the concentration values of the metal in common rocks of all types. Results for copper and zinc in the Abitibi area of the Canadian Shield are compared to results previously obtained for the Canadian Appalachian region. The lognormal model is also applied to a set of 162 large gold deposits in the Abitibi area. In the second part of the paper, 1311 large and small gold deposits in the Abitibi area are modeled as discrete events. By means of a newly developed spatial clustering model it is possible to predict the variances of random variables for frequencies of deposits in cells of different sizes.

Jan 1, 1981

By J. P. Batcha, J. Robert Denny

Since 1964. Newmont Mining Corp. has been engaged in a systematic research and development of computer techniques for a variety of mine planning applications. The general objective of this effort has been twofold: first, to arrive at a viable near-optimum plan for mining a particular orebody and, second, to decrease the financial investment by reducing the man-hours required for mine planning. Three major phases in the evolution of Newmont's computer techniques for mine planning are discernible. In phase one, the computer's ability to duplicate manual drafting and contour mapping was developed. Obviously, all recognized geologic characteristics had to be included, and consequently the development of computer techniques for the proper incorporation of structure, stratigraphic trends, and other geological features was a significant aspect of phase one.

Jan 1, 1970

By J. F. Harvard

We might say that for the metallurgist time "ambles withal," for the mining engineer time "trots withal," and for the geologist, time "gallops withal." And anyone for whom time "stands still withal" does not belong in the mining community today! In this bicentennial year of the United States of America we sense the mystery of time and we feel the pulse of history, especially in our own profession. What was mining like 200 years ago? What is it like today? What will it be like 200 years in the future?

Jan 7, 1976

The Institute's stock of Volumes XXXI, LI, and LII has become much reduced by sales. If members have copies of these volumes which they can spare, the price of $3 per volume will he paid for them, if in good condition. If desired, a copy of the Index for Volumes XXXVI to LV will be given for one of these volumes of the Transactions and one dollar additional. For two volumes of the Transactions, a copy of the Index will he sent and the balance will be credited to the payment of dues.

Jan 1, 1919

Zinc is just now a very important metal. Its use in cartridges and shrapnel brass are in the public eye. But its uses after the war are no less important. Brass as an engineering material for electrical machin-ery, journal bearings, and plumbing fixtures takes fully 50 per cent. of the production, and its use in these lines would have been increased in the last few years but for the price. Its use for barbed wire is probably more in war time than in peace. In the composition of paints, it is becoming more and more necessary. One of the forms of pigment, litho- pone, is the base of nearly all interior wall paints; of all the sanitary enamels for bath-rooms and bath-tubs, and is now in great demand. Zinc oxide is also increasing in use for paint, and for manufacture of linoleum. When we realize that this district-Missouri, Oklahoma, Kansas and Arkansas-produces now over one-third of the zinc ore of the world, it is at once seen that a meeting where the geology, mining, concentration

Jan 6, 1917

By V. M. Frey

IN 1936 the foreman at one of the oldest limestone quarries in northern Virginia discovered the remains of three old well-drill holes that contained dynamite. As consulting engineer for the property, I was then called upon to devise a method for removing the explosive. As no exact formula for the handling of unexploded dynamite exists, the proper steps for removing it must always be dictated by local conditions. A description of the procedure in this case may, therefore, be of interest to others faced with a similar problem.

Jan 1, 1939

The Institute's stock of Volumes XXXI, LI, and LII has become much reduced by sales: If members have copies of these volumes which they can spare, the price of $3 per volume will be paid for them, if in good condition. If desired, a copy of the Index for Volumes XXXVI to LV will he given for one of these volumes of the Transactions and one dollar additional. For two volumes of the Transactions, a copy of the Index will be sent and the balance will be credited to the payment of clues.

Jan 12, 1918

The necessary funds have been provided for the award in 1915 of three prizes, respectively of $50, $30, and $20, for the best essays, or other papers, submitted in competition by Junior Members and Members of Affiliated Student Societies. The following rules for the competition are therefore established in accordance with the instructions of the Board of Directors May 22, 1914: (1) A competitor for the President's Prizes must be, at the time of submitting his essay, either a Junior Member or a Member of an Affiliated Student Society of this Institute.

Jan 1, 1917

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Mine and mill accountant for Mexico. Knowledge of Spanish desirable. Salary $150 to $200 gold per month with living quarters. No. 60. Master mechanic familiar with mine and cyanide plant machinery for Mexico; $200 gold per month and living quarters. No. 61. Electro-metallurgist for production of ferro-alloys, salary $200 to $400 depending on experience. No. 62. Man familiar with ferro-tungsten products of electric furnaces to draw up specifications for machine tools, to watch these tools in service and revise specifications accordingly. Salary $150 to $200 per month. No. 63. Engineers under 35 years of age for placer mining work in Belgian Congo; $1,500 to $1,700 plus traveling and living expenses, two years' contract. No. 67.

Jan 2, 1916

By H. L. Talbot, A. J. Hall, R. S. Young

A METHOD for the chemical differentiation of oxidized cobalt from sulphide cobalt in complex mine and concentrator products is of considerable interest to a number of mining companies throughout the world. At Rhokana Corporation, in Northern Rhodesia, for instance, cobalt is found chiefly in the sulphide form, as carrollite, but a cobalt oxide mineral also occurs irregularly underground, and relatively small quantities in the mill feed from time to time are difficult to detect it visually at the concentrator. The oxide cobalt is not amenable to the sulphide flotation process used at Rhokana and nearly all of it passes into the tailing. The occasional. period when high tailing losses occur with no appreciable change in the cobalt content of the mill feed has naturally been disturbing to the concentrator staff, who had no means of determining whether an influx of cobalt oxide ore or laxity on the part of the mill flotation operators were responsible for these results. A procedure for determining oxidized copper minerals, based on their solubility in dilute sulphuric acid saturated with SO2, has been used for many years in the copper industry. In the presence of cuprite the procedure fails, but otherwise it gives results quite satisfactory for control purposes. Empirical methods for determining oxidized forms of zinc and lead have been proposed, but they are generally unsatisfactory except in isolated cases of a very simple ore. No published procedure for determining oxidized forms of cobalt or similar elements has come to the authors' notice. EXPERIMENTAL PROCEDURE There are obviously two alternatives in attacking a problem of this nature. One is to employ a solvent for oxide cobalt that will not dissolve cobalt sulphide. The other is, to find a substance capable of oxidizing the cobalt sulphide to sulphate, which of course is water-soluble and can then be leached from the water-insoluble oxide cobalt. A representative sample of Rhokana cobalt oxide ore was secured, ground to minus 200-mesh, and carefully rolled to furnish a standard sample for this work. The analysis of this material gave the following percentages: Co, 0.55; Cu, 1.64; Fe, 2.98; S, 0.08; SiO2, 41.42; A1203, 11.20; CaO, 13.82; MgO, 3.80. As a source of cobalt sulphide a similar large sample of carrollite was prepared, analyzing Co, 23.36 per cent; Cu, 27.32; and S, 31.13. This sample of course was not pure carrollite, but was the best obtainable in quantities sufficient for a standard intended for considerable work. It was a pure sulphide sample, microscopic examination showing only carrollite, a little bornite, and gangue, with no visible sign of oxidized ore present. A wide variety of reagents were used in an effort to selectively dissolve oxide cobalt or to oxidize sulphide cobalt to

Jan 1, 1946

By Charles Legrand

The problem of mine pumping is so much affected by local conditions, and those conditions are so liable to changes during the life of a mine, that the best system to use is difficult to determine. The experience of the writer has been that, in general, for copper mines, electric pumping is most satisfactory unless the quantity of water to be pumped is great or the mine does not use electric power for any other purpose. As a rule, however, figuring on the cost of necessary power plant, the total cost of installation is greater with electric pumps than steam pumps. As the water is liable to be gritty, outside-packed plunger pumps are to be recommended, and if the water is not acid, or only slightly so, chilled cast-iron plungers pay for their extra cost very quickly in diminished cost of packing. With chilled plungers it is possible to use metallic packing instead of soft packing, if the water is not too gritty or the lift too high. In vertical pumps this packing is satisfactory for lifts up to 400 ft., in the experience of the writer, and may be found satisfactory for higher lifts. For water slightly acid, cement-lined pump bodies have given good satisfaction. For acid water, both plungers and puhp bodies should be made of acid-resisting bronze. For high lifts, especially with gritty water, a satisfactory pump valve is difficult to find. To reduce the unbalanced pressure on the valve at time of opening it is advisable to have narrow seats; this, however, brings high pressures on the seats when the valve is closed. On large valves for lifts of 600 to 1,000 ft. we have used leather, hard rubber, vulcanized fiber, and soft brass; for clear water the latter has given best satisfaction. The difficulties due to grit make it advisable to have large sumps where water can settle, and if possible, to have two of them so that they can be cleaned alternately. At the mines of the Old Dominion Copper Mining & Smelting Co., Globe, it was found that a small air ejector discharging into a mine car provides a very convenient way to clean mud and sand from a sump.

Jan 1, 1916

The House Committee of the Engineering Societies Building has lent to he members of the three welfare committees a room on the ground floor of the building where they can carry on some of their war activities. Two sewing machines and two knitting machines are installed there and ladies are invited to sew for the Foreign War Relief Committee and knit for the Emergency Committee, which is working for the 27th Engineers, a special mining regiment. The Emergency Committee, Mrs. H. Norman Spicer, Chairman, reports the formation of a committed of 21 members. The organization meeting was held March 7, and plans were made for future activities as follows: A letter was read from Mr. Ingalls asking for 72 sweaters, 72 helmets, 66 pairs of wristlets as well as 772 pairs of socks, 272 being for immediate delivery. To meet this request it was decided to secure the helmets and wristlets from the Navy League, and to undertake the making of the sweaters and socks ourselves. Accordingly Mrs. H. N. Spicer and Mrs. J. H. Devereux were empowered to buy wool in sufficient quantities, and woven material for the 72 sweaters, sending the bills to Mr. Ingalls, who had guaranteed the money from the Engineering and Mining Journal. This was attended to promptly, and the materials were ready for distribution to the committee on March 13. After considerable difficulty, knitting machines for the socks were discovered and the agent came to demonstrate them. Mrs. Spicer gave one to the Committee and Mr. Ingalls has guaranteed the money to buy two when the manufacturers can deliver them. Up to April 6, 130 pairs of socks, machine and hand-knitted, have been handed in-also 68 sweaters, 80 helmets and 90 pairs of wristlets. It has been calculated that it needs five women knitting behind each man at the front to keep him continuously supplied with knitted garments.

Jan 5, 1918

IN order that you may be expert in every phase of this art of parting, I wish to caution you upon twelve points, all necessary, so that you may know beforehand what may happen to you and what provision you must make to obtain good results. Understand that the gain derived from this art lies in carrying out the work that you wish to do accurately and with profit, which means nothing other than working with certainty and seeing that there is no loss of gold or silver [69v] or substance of anything that is valuable in itself. For, since everything lost is silver or gold, it is valuable however little. it may be, and many little things obviously make one large one; for gain increases gain, and loss, loss. Therefore, you will have as your first task to seek to have the materials that you are to use for making the aqua fortis of as perfect a nature as possible. I tell you this because the saltpeter is often weaker and of worse quality than the alum. For this reason it is necessary to make an effort to have it not only well refined and free from earthiness but also of a nature as powerful as pig [dung] saltpeter, the color of which tends strongly toward yellow. In order to work better, you also refine this again before you put it to use, as I shall tell you in its place. Likewise, see if you can get alum of the red kind that comes from the Levant or from Cartagena, for it costs less and is more powerful. Furthermore; see that you have a good number of well-formed cucurbits of properly purified glass not too large and of, equal content and size. Above all, see that they contain, no indentations, bubbles, folds, or scratches, especially, in the, body or in the bottom, because they break easily and the nature and great force of the acid pierces them by eating away, and makes a little hole. For this reason, cucurbits. are always divided into four grades; one is taken for making aqua fortis, another for drying the waters when they are laden with silver, the third for recovering the acids from the separations, and the fourth are either rejected as useless or dangerous, or are saved for recovering the whites or for some other service. Whoever wishes to practice this art well should remember to keep a large supply of cucurbits, receivers, and alembics. The third is the precaution which one must take in luting them; first, to

Jan 1, 1942

By J. P. Manning

UNQUESTIONABLY, the outstanding feature of the piping for the sulphide plant is the large amount which had to be done in almost every size from instrument tubing to 84 in. OD pipe. In this article the piping will be considered under the main headings of Yard Piping and Building Piping. Tables I and II give data concerning the individual systems. In the case of yard piping the figures pertaining to lengths and weights are approximately correct; those for building piping are given only for the concentrator and smelter buildings where the amounts were the most extensive. Yard Piping The installation specifications for yard piping called for all sizes larger than 12 in. to have welded joints made with outside welding rings. This type of joint was selected over butt-welded joints because less time would be needed for lining up, damaged pipe ends would be less of a problem, and deflections up to 6° per joint could be made when necessary. These advantages were thought to outweigh the disadvantage of the greater amount of welding required. Yard piping in sizes of 3 to 12 in. was specified to have butt-welded joints made with inside welding rings which were intended to facilitate lining up and keep welding material out of the lines. Screwed connections were specified for sizes under 3 in. No protective coatings or wrappings were required on pipe to be buried because of the dry climate at Chuquicamata.

Jan 1, 1952

By H. M. Chance

THE present value of most coal properties resides largely in the coal remaining to be mined, which thus constitutes the most important asset. The object of this paper is to discuss methods commonly used in computing the value of mineable coal. To distinguish clearly between such coal values and the values of other property, the several kinds of property values may be divided into classes; this is necessary to avoid unintentional omissions of items of importance. VALUE OF COAL RESERVES Judicial decisions prescribe, and appraisers commonly accept, current sales value as the preferred means for determining the value of transferable property. With few exceptions a property is worth the sum that can be realized from its sale by a willing seller to a willing buyer, a sale in which compulsion urges neither party, and between whom there is no community of interest to fix a value; or it is worth at least as much as a responsible buyer will offer for it. Actual sales of like property or bids from responsible buyers for the property, or for substantially like property, are the best established methods for determining values. Only in the absence of such sales or bids can valuations by other methods be entertained, and only for reasons of weight can sales values be set aside. Sales of coal in the ground, as customarily carried out through lease, under royalty agreements, are therefore the most trustworthy means available for determining the value of coal reserves.

Jan 6, 1926

By H. C. Gatos, Ahmed Azzam

A UTORADIOGRAPHY would appear to be sim-A pler and less time-consuming for diffusion studies than any of the radioactive tracer techniques commonly employed, namely, the sectioning, surface increase, and surface decrease techniques.' Accord- ingly, it was felt worthwhile to investigate the applicability of autoradiography to self-diffusion measurements, and gold was chosen for this purpose. The radioactive isotope Au'!'' was used, as obtained from the Brookhaven National Laboratory. Its radiation consists of p (0.97 mev) and y (0.41 mev) rays, and it has a half-life of 2.69 days. No-Screen X-ray film was found suitable for these experiments: the film has the desired high speed for recording P rays and yet is practically insensitive to y rays. On the other hand, due to the high atomic weight of gold, this metal is a strong absorber for p rays. The

Jan 1, 1953

* A loan, perhaps as great as $100 million, from American insurance companies is about negotiated for development of Labrador iron ore properties. The program will call for a total expenditure of up to $200 million, including, as well as all mine development work, the power facilities, housing for mining personnel, and auxiliary equipment. * Mobile air compressors and a water tank, mounted on a 30-ton rubber-tired trailer and towed right up to the drilling crews, eliminates the need for expensive underground water and air pipe lines in the experimental oil shale mine operated by the Bureau of Mines near Rifle, Colo.

Jan 11, 1950