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By A. Ojanen, T-L. Huggare, A. Kuivala

An electrolytic zinc plant with a capacity of 90,000 tons/year went on stream in Kokkola, Finland, in late 1969. It is a standard electrolytic zinc process plant; however, it has been subjected to several process improvements and enlargements during its time of operation. A fluidized bed roaster treats 500 tons/day of zinc concentrates which also contain mercury. Since the mercury evaporates completely in the roasting process, a mercury removal unit has been added to prevent, contamination of sulphuric acid produced in the neighbouring acid plant. The same unit also removes selenium from the roaster gases. In a separate unit, about 6 tons a year of metallic 99.999% mercury is recovered. The neutral leaching, originally a batch process, has been converted to a continuous operation, and a residue treatment system comprising hot acid leaching and jarosite precipitation has been added. Purification comprises a "hot arsenic-zinc dust" step and a cadmium removal step with zinc dust, both operated batchwise. Purification residues are used to make about 200 tons/ year of 99.99570 cadmium in a process developed by Outokumpu Oy. The electrolytic precipitation of zinc carried out at medium current density gives zinc of 99. 995% purity.

Jan 1, 1973

By R. W. Jigins

OPERATIONS of the Braden Copper Co. are in the Chilean Andes, southeast of Santiago. Most remote of the company communities is Sewell, a town of 12,000 people, 7000 ft above sea level at the junction of the Coya and Teniente rivers. Four miles down the Coya River is the smelter town of Caletones, elevation 4500 ft, with a population of about 3000. At the junction of the Coya and Cacha-poal rivers 24 miles below Sewell is Coya, elevation 2500 ft, location of the company's two hydroelectric plants. The principal accounting offices; steel, iron, and brass foundries; railroad shops; and major mechanical repair and fabricating shops are at Rancagua in the central Chilean valley, 44 miles from Sewell. The company owned narrow-gage railroad connects with the Chilean national railroad at Rancagua and above Coya is the only modern means of travel. El Teniente mine at Sewell is the largest underground copper mine in the world. The mill, at the portal of the main tunnel, has a capacity of 34,000 tons of crude ore daily, although production is lower during the winter beacause of electric power restrictions. When operating at capacity the mill produces 2000 tpd of copper concentrates and 32,000 tpd of tailings. Tonnage of tailings is equivalent to about 100,000 tons of pulp at normal water to solid ratio. Because the streams flowing from the Andes in the area of Braden's operations are used for irrigation, it is impossible to dump tailings directly to the river. The tailings pulp must be separated into solids and decanted clear water, and the clear water returned to the same water shed from which the original water was removed. Remaining sands and slime must be deposited in a reservoir where they will not cause trouble to farmers.

Jan 1, 1958

By Donald W. Scott, Adam L. Wesner

THE inevitable depletion of Mesabi direct-ship- ping iron ores, hastened by recent wars, has increased the importance of developing methods to concentrate iron-formation materials. Many mining companies, independent research organizations, chemical companies, and equipment manufacturers are devoting attention to this important work. It is only natural that magnetic iron-formation materials have received major emphasis, since magnetic recovery methods apply and reserves of Mesabi magnetic taconites are large. However, the non- magnetic* iron-formation materials are likewise believed to represent a large reserve and their study has not been neglected.

Jan 6, 1954

By A. T. English

X-ray dif action techniques were used to investigate ordering and domain coalescence for the B2 (CsC1) superlattice in this alloy. Essentially complete disorder is obtainable by drastic quenching. isothertmal ordering occurs very rapidly at temperatures between 565° and 680°C, only a few seconds being required for development of substantial long-range order. A very fine antiphase dormain structure, found in samples annealed for short times, undergoes coalescence with further annealing. Domain "size" is found proportional to (t)1/2 . This Yate law can be derived by adapting the formalism of Hillert's analysis 01- metallurgical grain growth. For this Purpose the material is descvibed in terms of a "Swiss-cheese " structure, consisting of two multiply connected, mutually intertwined domain volumes. The observed activation enevgy for coalescence, 70 kcal per g-atom, agrees with an estit~lated value ,for volume diffusion in disordered rrzaterial. It is suggesled that the experimental value vejlects the substantially disordered environment of mobile vacancies located in the moving antiphase domain boundary. The alloy Fe-Co-2V is bcc below about 900'C and orders into a B2 (CsC1) superlattice below about 730c It has important applications in magnetic components, including many requiring extensive cold rolling.* example, Marcinkowski and Brown6 observed a re1atively small as-quenched domain size of about 250Å in B2 Fe3A1. Since there appear to be no published data on domain coalescence in B2 alloys, this process was studied in detail. MATERIALS AND EXPERIMENTAL TECHNIQUES A commercial high-purity alloy, nominally 49 Fe-49Co-2V, was obtained from the Arnold Engineering Co. in the form of cold-rolled sheet 0.004 in. thick. Samples were annealed for 1 hr at 800°C in dry H2 to produce disorder and quenched into iced brine. They were then annealed in a nitrate-nitrite salt bath for various times at temperatures between 525° and 625°C. Estimates of the LRO parameter S and the APD size D were made using established X-ray diffraction techniques. Superlattice peaks are best observed using CoKa radiation, for which the value of (fFe-fCo) is maximized. Peak-to-background intensity ratio was improved by filtering CoKß from the incident beam to eliminate sample fluorescence, and by using a pulse-height analyzer. The LRO parameter S was computed from the ratio of integrated intensities I 100/I 200- Owing presumably to systematic errors associated with the presence of crystallographic texture and X-ray extinction, only rough agreement was obtained between experimental and theoretical (absolute) intensity ratios. For this reason certain experimental refinements (e.g., use of balanced filters) were considered superfluous and were omitted. Emphasis was placed on maximizing intensity in order to reduce the time taken to accurately determine the contour of the very small (loo), peak. This was done by point counting 105 counts at appropriate intervals. Background intensity averaged about 1200 cps.

Jan 1, 1967

In mid-November, a long awaited announcement was made by John Drybrough, President of Granduc Mines Ltd. In short, he said that the extensive exploration conducted by his company and its parent organization, Newmont Mining Corp., have indicated the feasibility of a commercial copper mining operation at the company's prospect located slightly north of Stewart, B.C., and just east of the Alaskan Panhandle. The financing of the project is now being planned. SUMMARY OF PROJECT Granduc reasonably assured ore reserves are estimated at 32,510,000 tons averaging 1.93% copper content before dilution, of which 20,670,000 tons averaging 2.08;:; copper content are situated above the proposed mine access tunnel at elevation 2475 above sea level. The life of the reserves at the planned rate of production is 13 1/2 years. The probability of finding substantial additions to these present reserves is considered good.

Jan 12, 1963

By R. W. Mancantelli, J. R. Woodward

In 1947 a large low grade deposit of uranium was located in the northwest corner of Saskatchewan, in the Beaverlodge property of Eldorado Mining & Refining Ltd. Most of the values occur as thin seams and as coatings on other minerals, and the ore, which is light and friable, is not amenable to the usual gravity methods of concentration. The acid leaching process developed to retreat the company's Port Radium tailings was also impractical, as the percentage of carbonates is high and the percentage of sulphides relatively low. Construction of the mill building and installation of equipment, both scheduled for 1952, awaited selection of a satisfactory ore dressing process on or before Oct. 1, 1951. An extensive research program on dressing of ores from the Ace mine therefore was undertaken by the Mines Branch in Ottawa, a research team at the University of British Columbia and an ore dressing group at the company's Port Hope refinery.

Jun 1, 1955

By H. A. Doerner

PROPOSALS to use hydrocarbon or natural gases for the reduction of zinc from oxide materials may be traced back through Patent Office files to the early years of the present century. Natural gas at rates cheap enough to compete with solid fuels has been available at or near one major zinc district for more than a decade. That the seemingly meritorious and economically interesting applications of these proposals have not devel-oped into workable processes for direct production of zinc by natural gas cannot be completely ascribed to the proverbial conservatism of the zinc industry. It is possible to produce spelter commercially in normal times from zinc oxide and carbonaceous reducing agents without having a very precise understanding of the chemistry of the process. The reduc-tion by hydrocarbons is not, however, in this class, and the technical complexity of this reduction metallurgy and chemistry prohibits solution of the inherent difficulties by the "hit and miss" methods that are some-times thought to be practical. In a thermodynamic study of the chemistry of zinc smelting, Maier1 made a preliminary study of the chemistry of the use of methane for reducing zinc oxide by thermodynamic means, pointing out that the following reactions, the limits of which could be theoretically predicted, were important: ZnO + CH4 = Zn(gas) + CO + 2H2 [1] CH4 = C -I- 2H2 [2] ZnO + CO = Zn(gas) + CO2 [3] ZnO + H2 = Zn(gas) + H2O [4] Other possible reactions, not discussed in the reference quoted, are: CO2 + CH4 = 2CO + 2H2 [5] H2O + CH4 = CO + 3H2 [6]

Jan 1, 1933

By Kenneth A. Grace

Jan 1, 1985

By David H. Browne

One of the most difficult problems in the chemistry of iron-ore, and one, the solution of which, so far as I am aware, has never been attempted, is the distribution, throughout a given vein, of Bessemer ore, and its relation to the formation of the deposit. In those hematite-mines in which both Bessemer and non-Bessemer ore occur, the sorting of the ore as it lies in the deposit becomes a problem of much economic as well as scientific interest. It would seem, from a superficial examination. or, indeed, from any examination not conducted for this especial purpose, as if high- and low-phosphorus ores were mixed in inexplicable confusion ; and a mining-chemist is very apt to fall into a system of adventitious analyses, taking first-class ore wherever he can find it, and overlooking its relation to the formation and position of the vein. I hope that a few notes which I present on this subject may be found worthy of consideration, as throwing a new light upon this obscure topic. During the last three years, while acting as chemist of the Lumberman's Mining Co., I have made some 3000 analyses of iron-ore from the Ludington mine at Iron Mountain, Michigan. These analyses were necessary in order to separate Bessemer and non-Bessemer ore which occurred intermixed in the deposit. During the last year, I attempted in several ways to find some reason or method in the distribution of phosphorus, and have finally become cognizant of the arrangement herein outlined. I have been obliged to confine my attention to our new mine, and, in that, to that portion wherein

Jan 1, 1889

At its meeting on February 21, 1933, the Board of Directors passed the following resolution defining and expressing the policy of the Institute with respect to official participation or action in controversial matters: WHEREAS, the Board of Directors at its last meeting passed the following resolution: "The Board of Directors, having been appealed to by several Local Sections for advice concerning the attitude and policy of the Institute relating to the endorsement of candidates for public office, the following statement of policy is formulated;

Jan 1, 1932

POSITIONS VACANT Wanted, for a new smelting company now being organized in China: one man familiar with the design and operation of a zinc smelter; one experienced in the design and operation of a lead smelter; and a chemist competent to make the usual analyses in connection with lead and zinc smelting and to make clay analyses. Men with their wives preferred. Company will pay all expenses to and from China, medical attendance, salary, bonus per ton of zinc or lead produced, allowance for food, and furnish quarters. No. 120. . . ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, oil geologist, age 33 years, technical education, nine years' experience with oil and mining companies, wishes employment with repu-

Jan 8, 1916

By Harlan A. Walker

ROCK-DRILL steel has an important bearing on costs in many mining operations, both directly and indirectly. Direct factors include such items as shop expense, steel consumed per ton of ore produced, cost of distribution and the dust hazard. The latter, although no specific amount may be assigned to it, is an ever-present problem, and is receiving increased attention as the science of mining progresses. Indirectly drill-steel performance affects consumption of compressed air, maintenance of drills and drilling speed. The latter, in turn, increases or retards the tempo of mining and development. These factors, while not all inclusive, are preponderant in their importance. Thus it is evident that in an extensive operation drill-steel expense may run to many thousands of dollars and that thoughtful research leading toward more efficient practice is warranted. EXPERIMENTAL WORK During the late spring of 1939, experiments were undertaken at Homestake in reducing changes in drill-steel gauge from 1/8 in. to 1/16 in. [ ] In drifts and crosscut headings mounted machines were set up and holes were drilled with 1/8-in. bit-gauge changes and other holes a few inches

Jan 1, 1940

By Barnabas Bryan

In the year 1875, the Pennsylvania Supreme Court, acting on incorrect information concerning the production of oil and gas, established what has become the law of the land for the governing of oil production. While the decision was ideal for the refining monopoly which was completed in that year, there is no evidence that the court was in any way influenced by that refining monopoly. The evidence indicates that the court accepted the view of the royalty owner and independent oil producer. Throughout the life of the refining monopoly it accepted this law, which was so evidently to its advantage in securing cheap raw material. The same policy continued until the development of the exhaustion theory and the entry of the various units of the former monopoly into the production of crude oil. It is curious that no one doubted the new theory of shortage sufficiently to feel the need of changing the law. When the theory entered the economic field sufficiently to raise crude oil prices beyond justification it shortly disproved itself, but by this time the question of split ownership in producing fields made a change from legal error to justice too complicated to be undertaken by the large companies. Not even the ardent advocate of unit operation dared to carry the question to the United States Supreme Court, which has never been asked to pass on the complete question. The impossible position of the producing industry, hemmed in on one side by court law compelling wasteful production and on the other by the national law against cooperation, lasted until the demoralization of 1927 led to cooperation within a state and under state guidance. Since that time control of production has grown with the bringing in of each new field and at this time has the active support of the Department of the Interior in such ways as are definitely legal. As in 1875, the royalty owner and independent producer are opposing by all possible means the rational conduct of the business of producing crude oil. Fluctuation in Investments The investor in oil securities has not been as badly fooled as has the oil man himself. Fig. 1 is designed to show the composite regard of all

Jan 1, 1930

By P. A. Albert

THE to a transformation has been investigated by Newkirk1 in sponge titanium alloys which had been relatively slow-cooled so that several grains formed in a former grain. For a nucleated from , Newkirk assumed the following relationships and found them consistent with his experimental results: (00.1)a (110)Pll.01. II [111] Liu and Margolin,' in their investigation, found that the habit planes of martensitic in titanium consisted of planes of the families (3341, and (3441,. Using Newkirk's orientation relationship, the (3341 habit plane is found to correspond to the (1450) plane of a.

Jan 1, 1954

By Robert Glass Cleland

UPON the death of its founder, Phelps, Dodge & Co. entered upon a new chapter in its long and varied history. Thereafter, for nearly a decade, William E. Dodge largely determined and executed the policies of the company. The old firm, dissolved automatically by Phelps's death, was succeeded by a new partnership consisting of Anson G. Phelps, Jr., William E. Dodge, Daniel James, James Stokes, William E. Dodge, Jr., and D. Willis James, one of the three sons of Daniel James. Each of the first three partners owned a twenty-five-per-cent interest in the company, Stokes had a fifteen-per-cent interest, and the two younger partners each held five per cent. The new company bought Anson Phelps's holdings in the old firm from Olivia Phelps, his widow and executrix, for approximately seven hundred thousand dollars; but the new partnership, designed by agreement to last the usual five-year period, was brought to an end shortly before that time by the death of the younger Anson Phelps from small- pox. Perhaps because of poor health, the son had never been as deeply concerned with business as his father, but found

Jan 1, 1952

By Agustin S. Segura, Luis G. Gutierrez

Foreign investment in Mexico, particularly of American capital, has increased steadily since 1940. At present, however, these investments are less important to the Mexican economy than in earlier periods. In the last few years, local or Mexican capital has participated in most American investments in Mexico with the encouragement of the Mexican Government. Foreign investment in a wide variety of industrial activities has gone up in the last decade, placing mining investments in second place. This growth is the result of the Mexican Government's favorable attitude toward industrial expansion. The process has been encouraged through tax exemption on infant industry, through customs protection, and through other incentives.

Jan 11, 1959

By R. K. Adams

The availability of digital computers costing less than $15, 000 makes them economically attractive as versatile research and experiment tools. Several such installations at Oak Ridge National Laboratory have shown that improvements in research productivity and experimental control accuracy can result from the proper application of a small digital computer. However, careful attention must be paid to several potentially expensive problems in 1) interfacing the experiment to the computer and 2) programming the computer. Two specific applications of very small computers to metallurgical testing and research are described. One is a system for data acquisition and precise temperature control associated with a thermocouple testing program, and the other is a system for pulse calorimetry determination of the specific heat of metals over wide temperature ranges and in the neighborhood of metallurgical transformations. The data acquisition system which uses a PDP-8/S computer monitors signals from up to 264 low-level thermocouple signals at two scanning speeds: 10 readings per second for long-term drift data, and 500 readings per second for transient data. The pulse calorimetry system which uses a PDP-8 computer accepts up to 6 signals of 0- to 10-v range and because of a larger analysis program, uses a bulk memory (magnetic disc) in addition to core memory.

Jan 1, 1969

By AIME AIME

T HE appointment of Herbert Hoover to the portfolio of Commerce in the President's Cabinet is to engineers the fulfillment of a long deferred hope to have an engineer in high political office and is a matter of congratulation to us for three reasons; because he is a mining engineer who represents the highest type of idealistic engineering effort; because he is a past president of the Institute; and because he has probably a broader grasp of world problems than any other living engineer. Frank A. Vanderlip in the preface to his book "What Happened to Europe" tells of the many interviews he had with the most prominent men in Europe which were made possible for him by his eminence as a banker and by the courtesy of the American ambassadors. He cites by name such well known figures as Austin Chamberlain, Sir Auckland Geddes, Monsieur Delacroix, Monsieur Briand, Mr. Padkrewski, Mr. Venizelos, Colonel House, General Pershing, Mr. Baruch, and many others and says :

Jan 1, 1921

By E. S. Machlin, A. A. Hendrickson

Use was made of a recently developed surface-accumulation diffusion technique to measure the self-diffusivity of edge-type dislocation singular lines (Burgers vector along <110>) in a bent and polygonized single crystal of silver. Two factors are involved in obtaining a number for the diffusivity. One factor, the dislocation-line density, was measured by a microscopic technique recently developed, and the value of the other parameter, the effective "diameter" of a dislocation pipe, was estimated. With these parameters equal to 7.3 X 106 dislocations per sq cm and 10-7 cm, respectively, it was found that the self-diffusivity along edge-type dislocation lines was a factor of about two times the average grain-boundary self-diffusivity. The dislocation-pipe diffusivity is about 7x10-7 sq cm per sec at 450°C. THE possibility of short-circuit diffusion through imperfections in crystals has been recognized for some time. It was only recently, however, that concerted effort has been expended to obtain values of diffusivity for grain-boundary short circuits. The work, for example, of Hoffman and Turnbull1 on silver, Fisher&apos;s&apos; analysis of the grain-boundary dif-

Jan 1, 1955

By Richard A. Arnold

The evolution of planning processes in the United States from the early 1900&apos;s is briefly examined. From one year operating budgets, planning processes have evolved into sophisticated analyses of alternative long-term future strategies and the management issues and practices which relate to their implementation. Increasing complexity within the business environment has led to numerous planning methodologies and extensive use of computers to analyze operating and financial information. All of these developments, however, have not supplanted the real need for decision-makers to continue to give important weight to the intuitive or soft data inputs into the planning process.

Jan 1, 1985