Search Documents

By C. Schwandt

Recent research work has led to the development of a new electrochemical hydrogen sensor, which is based on a proton conducting solid electrolyte in conjunction with a self-contained solid hydrogen reference standard and is operated at elevated temperatures. The incorporation of the internal hydrogen reference renders the sensor versatile and user-friendly and makes it attractive for practical exploitation. The present article focuses on the utilisation of the sensor as the integral part of a probe for the quantitative determination of hydrogen in molten aluminium and aluminium alloys. The main features of the sensor and the probe as well as the measuring technique are discussed. Experimental results obtained with the novel analyser in trials under industrial conditions are presented and highlight the good performance of the device.

Jan 1, 2003

By B. K. Mishra

Power draw of the mill has been accepted as an indicator of the performance of the mill, yet the problem of predicting power under a given set of mill operating conditions still remains to be solved. In the literature, this problem of predicting power is attributed to a lack of knowledge with regard to the motion of the charge. Here a DEM based model is used to analyze the motion of the charge. The resulting information is used to predict the power draw of the mill. A 16-ft diameter mill is simulated. A factorial design study of the variables-mill speed, lifter configuration and ball size distribution-as independent variables is taken up. The power draw as a response variable is analyzed to establish the best operating condition of the mill.

Jan 1, 1993

By AIME AIME

THOUGH the Annual Meeting of the Institute-officially numbered 158 on the records was delayed a bit at the start by low steam pressure on the locomotives bringing members to New York, the crowd that finally arrived more than lived up to expectations, and the technical program had few difficulties because of absent authors or lack of competent discussers. The transportation difficulties were occasioned by the fact that Monday, Feb. 15, was the third coldest day in the 72 year history of the New York Weather Bureau, the official temperature being 8 below zero. The New York Central's premier train, the 20th Century, due at 9:30 a.m., arrived about 6:30 p.m., and the Commodore, another crack train from Chicago, was about equally late.

Jan 1, 1943

By W. J. Mahoney

A good quality assurance program at a coal mine or power plant is accurate, timely, and consistent. The quality analysis is accurate due to a complete sampling of the coal stream loaded into the unit train. The sample analysis is accurate because standardized testing procedures are applied. Once the analysis is completed, the results must be communicated to the electric utility in a timely manner. The electric utility needs the results to better manage the coal inventory at the power plants. A quality assurance program can also help the mine deliver a consistent product to the electric utility's power plants. The importance of the three major tenants for a good quality assurance program: accuracy, timeliness and consistency, are based on major changes that are taking place in the electric utility industry.

Jan 1, 1994

The appraisal of mineral reserves by a lender is carried out at the initial stages in developing a loan for a mine. The depth of investigations is influenced by the competence of the explorer, the type of commodity and knowledge of the geological environment. The lender looks for a reserve life which exceeds the term of the loan plus contingencies for events such as cost over-runs, adverse markets and production difficulties. The physical features of importance are discussed. Factors with direct financial implications are considered for their incorp- oration in sensitivity analyses to allow risk appraisal. When satisfied, the lender can then proceed to review cash flow forecasts, the basic strength of the project, then determine with the borrower the components and alternat- ives of a loan package.

Jan 1, 1979

By Jinsheng Wang, Xueming Lv, Wei Lv, Junyi Xiang, Xuewei Lv, Chenguang Bai

In this study, microwave heating was used to dry the nickel laterite which contains plenty of free water, crystal water and hydroxy water. The results showed that compared with the conventional drying process, the microwave drying greatly improved the drying efficiency of nickel laterite. The whole microwave drying process can be divided into three stages according to the drying rates, namely, the rising stage, stable stage and declining stage. The effects of microwave power output and particle size were also studied in the range of 0.8–2.0 KW microwave power and 3–6 cm of particle size. The results showed that the drying time significantly decreased with the increase of microwave power and decrease of particle size. The phases transition of the sample during the microwave drying process were also discussed.

Mar 1, 2018

By Charles W. Huggins

Knoop hardness indentations were studied and measured with the electron microscope on TiB2, HfC, and A1B12 crystals. A detailed description of replicating the indentations using collodion and Faxfilm is made. A John Hopkins grating having 28,800 lines per inch was used to accurately determine the magnification used on the electron microscope. The primary objectives were to prepare carbon replicas of hardness indentations, to measure the indenations accurately, and to compare the results with those obtained with the light microscope. The resulting data showed excellent agreement between the measurements made on the replicas with the electron microscope and those made with the optical microscope. The replicas made from collodion showed slightly better agreement with the light optical values than did the replicas made from Faxfilm.

Jan 1, 1963

By AIME AIME

FOLLOWING careful study of the relations of the Institute to students and the younger members of the profession, the Membership Committee recommended to the Board a change of plans abolishing the Junior Associate class of membership, substituting a -Junior membership and providing for Student Associates. The Board adopted this report at its meeting on Nov. 23, and asked Counsel to draft the necessary amendments to the By-laws, and gave formal notice of intentions to amend as provided in Section I, Article XI1 of the existing By-laws. The By-laws as it is proposed to amend Article I, 11, 111, IV, X, and XI follow. The new plan requires no changes in the other Articles. The matter will come before the Board for vote on Jan. 25.

Jan 1, 1929

By K. L. Kayler

The Bardon Trimount, Inc. stone quarry in Ashland, Massachusetts was the recent subject of a quarry closure review report. The quarry produces aggregate using standard drilling and blasting techniques. Stone is processed at an on-site plant. Noise monitoring data collected during the closure review indicate that the quarry generally operates within the quiet range. There is a decrease in noise while the quarry is not operating. Levels of dust associated with the quarry are low. Unpaved roadways are the greatest contributors of fugitive dust associated with the mining operation. The quarry cannot be seen from any homes within the town of Ashland, except during the winter months. The visual impact of the quarry on surrounding properties is minimal. Further quarry development is likely to reduce visibility of the quarry from some areas.

Jan 1, 1995

By D. Mu

A method is presented for evaluating the effective gas diffusion coefficient of porous media. A series of random-distributed porous solids with different porosity are generated, a solution of the gas diffusion equations inside the porous media is obtained using the finite element method (FEM), and then the effective gas diffusivities are computed. The results show that there is a percolation threshold sp, and this percolation threshold decreases with an increase in the connectivity of the pore network; the relationship between the effective diffusivity and the porosity is strongly nonlinear when the porosity £ is less than about 0.2; and is quasi linear for higher porosities. The threshold decreases with increasing the connectivity of the pore network. A formula relating the effective diffusion coefficient with porosity is proposed.

Jan 1, 2005

By Hong-ying Xia, Bao-bao Wang, Jin-hui Peng, Bing-guo Liu, Li-bo Zhang, Zhi-qiang Li

Based on optimization using response surface methodology designed by Box- Behnken, to study the interaction of wet industrial salt with moisture drying temperature (50-90 ); duration (10-50s); and the weight of the materials (20-60g). The results show that: the experimental parameter conforms to the quadratic equation model to influence the moisture content and the dehydration speed., in analyzing the significance and the interaction of various factors, the optimum by the Design Expert software conditions for drying with microwave radiation include temperature of 90 , duration of 10s, and sample mass of 26g. Verified by experiment, the moisture content after drying is less than 0.25% and the dehydration rate reached 1.37g/min, between the predicted value and the actual value confirmed good fitting degree.

Jan 1, 2015

By Shijie Wang

In pressure oxidation leaching of copper anode slimes, than 65% of the tellurium is m' cxtraoted during decopperizing. About l0- 15% of the selenium is also dissolved simultane¬ously by severe leach conditions. Current operation for the treatment of the leachate is to constantly recirculate the leach solution through a bed of copper turnings. The tellurium and sele¬nium are precipitated from the leach liquor as copper telluride and copper selenide and sepa¬rated from the solution by filtration. In order to improve the reaction efficiency and reduce the process cost, viz, minimize the copper addition, cut retention time, and reduce the energy consumption; a chemical reducing agent is studied and the cementation process tested in the laboratory. In this paper, the test results are presented and the process chemistry is discussed.

Jan 1, 2003

THE decision of the lower court (United States District Court for the Southern District of New York) in the suit of the Dwight & Lloyd Sintering Co., vs. John E. Greenawalt has been affirmed by the United States Circuit Court of Appeals for the Second Circuit. In the original suit, infringement of seven patents was alleged, these covering the process of producing a sinter .out of finely pulverized metalliferous ores as practised in shallow pans operating intermittently in distinction to the Dwight 6: Lloyd continuous machine. The court found that the long delay in bringing suit precluded any recovery of profits from the defendant under the basic down-draft sintering patent, although Dwight & Lloyd are recognized as the inventors of this' contribution to the art and its .importance is acknowledged.

Jan 1, 1928

By G. Noce

The ever more present necessity for greater precision in foundation structures on vertical piles subject to horizontal forces applied to the heads, in the light of of the latest knowledge about the elastic-plastic behaviour of the soil has led to the use of numerical calculation for the formulation of a general resolution method for the problem. The calculation method that will be set out, applicable to piles with inertia moments variable discreetly along their axes is especially useful when studying steel structures for medium and large tonnage vessels for which the metal piles are often constructed for the assembly of section of equal external diameter but different thickness and therefore different inertia moments. Two examples are given of constructions whose foundations have been projected with these calculation tools, one in the railway sector (foundation pile for the river Nera viaduct - Italy) important for the limitation of horizontal relative deck displacement, the other maritime (Dolphins of the petroleum pier of the port of Bandar Abbas - Iran).

Jan 1, 1989

By B. E. Ydstie, B. F. Lund, K. R. Løvåsen, B. A. Foss

The paper presents sensitivity analysis for a dynamic model of submerged arc silicon furnaces. The model we study, called ?Simod?, was developed by Elkem in cooperation with NTNU and Sintef. It is today a much used tool in Elkem for operator training and analysis of the dynamic behaviour of the silicon production process. The aim of our work is to bring the simulator tool closer to industrial practice, and construct a mechanism to adapt the model to the behaviour of a running process, online. The paper presents the results of the sensitivity analysis that has been undertaken for important parameters in the Simod model. The parameters associated with the process inputs are electric power loss, loss of fixed C and reactivity of carbon. The output signals that have been investigated are fed quartz, tapped silicon and silica. The paper also interprets the results of the sensitivity analysis in a process operation context.

Jan 1, 2004

APPLICATIONS for loan contracts for the exploration, development and mining of strategic and critical metals and minerals are now being accepted by the Department of the Interior. The RFC is authorized and directed by Executive Order 10161 to make such loans but the Secretary of the Interior must pass on the necessity for the loan. Applications should be addressed to James Boyd, acting deputy administrator, Defense Minerals Administration, Department of the Interior, Washington, D.C. rather than to the Field Offices of the Bureau of Mines as was first planned. Application forms are not yet available but it has been learned that data accompanying the application should include the known quantity and grade of reserves, the anticipated rate of production, the equipment, supplies, and man power required for the additional production, etc.

Jan 12, 1950

By AIME AIME

T HE Mid-Continent Section of the Petroleum Division met on Mar. 11 in the engineer's room of the Tulsa Building, Tulsa, Okla., for the purpose of reviewing the papers presented at the annual meeting in New York. L. G. E. Pignell, chairman and delegate to New York for the Mid-Continent Section, read a brief report giving the outstanding features of the various papers that were presented. He expressed regret that more members of the Division could not be present in New York to hear the interesting papers and discussions. It was his opinion that the various remedies presented for overproduction seemed rather theoretical and impractical and he recommended that the engineers come to the aid of some of the economists in giving more practical consideration to the overproduction problem.

Jan 1, 1929

By Yeatman, Pope

FOR many years geologists have felt that mining companies should adopt a more liberal policy in the publication of their reports. The increasing usefulness of the geologist to the mining profession in recent years demands that consideration be given to this question. Prior to 1900, the call for geologists of high reputation by mining companies was probably mainly in connection with lawsuits arising from the interpretation of rights or ownership as defined by the "Law of the Apex," and from problems such as finding the continuation of the vein or whether the vein followed was the main one or a branch. Later, outside of legal questions, the most intensive and general use of their services arose from the search for oil. Geologists to determine the position of the formations

Jan 1, 1938

By AIME AIME

T HE Institute of Metals Division and the Iron and Steel Division will meet jointly at the Stevens Hotel, Chicago, during the week of the American Metals Congress, Sept. 22-26. The Iron and Steel Di- vision of the American Society of Mechanical Engineers, the American Society for Steel Treating and the American Welding Society meet at the same time. but the sessions have been arranged to conflict as little as possible. A rich program of papers and plant visits has been arranged for the members and guests of the two Institute Divisions. The annual dinner and a pro- gram of entertainment are being arranged by the Woman's Auxiliary of the Chicago Section. Members are urged to register immediately up011 arrival and to make dinner and plant visit reservations at the same time.

Jan 1, 1930

By R. B. Taylor

"The Delnite mine is in the northwest part of Deloro township, Cochrane district. The property consists of 307 acres on the so-called 'South Break' in the Porcupine camp. The Company was formed in 1934 to take over the holdings of La Roche Mines, Limited. Gold has been produced continuously since June 1, 1937. The value of the gold recovered to date (December 31, 1946) has been $7,456,000, and the average grade of ore $6.81 a con.The ore at the Delnite occurs in relatively narrow, persistent, quartz-ankerite veins, which generally contain tourmaline and have a ladder-like structure. The gold occurs in the free state, and in association with pyrite and arsenopyrite, the two chief sulphides. The host rock is fine-grained, highly carbonatized andesite of Keewatin age."

Jan 1, 1954