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Jan 1, 1901

By S. R. Rao, J. A. Finch, E. El-Ammouri, K. Ngoviky, P. A. Disten

Sludges produced by lime treatment of acid mine drainage (AMD) can contain significant quantities of base metals which represent both a potential hazard and a loss of values. A new technique for metal recovery from sludge is proposed by combining selective acid leaching and adsorption of metal ions by activated silica sol. The process is demonstrated on two AMD sludges, one containing primarily nickel and the second zinc. They were first treated with sulphuric acid (pH 3.5) to selectively leach the target metals and then activated silica sol was added to the leach solution to adsorb the nickel and zinc. Thickening and centrifuging gave about 90 percent rejection of the input volume to effluent. The adsorbed metals were redissolved by strong acid into a concentrated solution relative to the feed and the silica sol was recycled.

Jan 1, 2000

By A. C. Atenas

The majority of refineries that operate with traditional starting sheet technology ?starting sheet- uses a relatively low current density of 250 A/m2. Industrial tests at high current density with conventional technology were carried out in Refinery of Potrerillos, getting satisfactory results that are similar the results obtained with permanent cathode technology. The series of copper refining electrolyses electrolysis trials were carried out between 300 to 325 A/m2. Electrolysis conditions, in accordance with industrial practice, were kept constant in all sets of experiments and were as follows; 45 g/L Cu 2+, 210 g/L H2SO4, 62 °C, electrolyte circulation of 14-18 L/min. The same Dosing dosing of Additives additives used in permanent cathode technology was required in these tests. In general, only not importantminor operational modifications were necessary in comparison to normal practice in the Refinery to assure the good results. Different quality of starting sheet and anodes were examined. The test included starting sheets from smelter and laminated process. Results indicate that the charge physical quality of the electrodes and the control of the process during the two first days of operation are the keys to get the best results.

Jan 1, 2007

By Rong Guo, Qi He, Jinsuo Zhang

"Coal mine ranks No.1 among the 6 major high-risk industries, so it is no doubt that the senior managers in the coal mine bear more stress than other industry executives. The massive working stress results in serious influences on the physical and mental health of the senior managers of coal mine, which might also induce the safety risk in the coal mine. Therefore, to evaluate the senior managers’ working stress and put forward strategies of mitigating the stress is of great theoretical and practical significance in improving the physical and mental health of the senior managers and reducing the safety risk in the coal mine. The research on the working stress has been made in the western countries for almost 50 years, China began the research in the mid and late 1990s, the research is spread across multiple industries including education, medical treatment, computer and aviation. However, there is little research on the senior managers’ working stress of the coal mine, so the available literatures are few. In the paper, we, based on the working stress model of Robbins and through questionnaire survey, analyze the element composition of the senior managers’ working stress of the coal mine; then, we construct the evaluation indicator system of the senior managers’ working stress of the coal mine based on the individual factor, organization factor and environment factor; after that, we determine weights of each evaluation indicators by using the improved triangular fuzzy number weight method, and set up the evaluation model of the senior managers’ working stress of the coal mine on the basis of the fuzzy comprehensive assessment method. At last, in accordance with the model, we evaluate and analyze the working stress for the senior managers of some typical coal mines, and diagnoses the major sources and intensities of the senior managers’ working stress, and then propose corresponding strategies of mitigating the stress."

Jan 1, 2017

By J. Marsden

Lift height, overall heap height and climate all play an important role in determining precious metals leaching rates, recoveries, operating costs and capital cost requirements for heap leaching operations. The effects of these factors are not easy to predict from testwork, and this can result in unexpected delays in metal production, lower recoveries than expected and higher capital and operating costs than necessary. This paper investigates the economic impact of lift height, overall heap height and climate on heap leaching and provides criteria to assist in the design and operation of leaching facilities. Descriptions of three heap leach operations in the western USA are provided to support the discussions and conclusions.

Jan 1, 1995

By J L. Maule, S J. Mathews, K A. Rodgers

Gold and Silver bearing epithermal veins of the Golden Cross deposit are hosted in Miocene and Pliocene calc-alkaline volcanics occurring 8 km northwest of Waihi at the southern extent of the Coromandel Peninsula, North Island, New Zealand. Veining occurred during a period of hydrothermal activity that began early to late Pliocene, and possibly continued into the Pleistocene.   Field relations and petrographic relationships reveal that multiple generations of FeS2 occur in the Golden Cross region, with FeS2 occurring in all nine rock types recognised at Golden Cross. The variability of FeS2 morphology was investigated by preparation of high purity FeS2 separates, and grain counting. Marcasite is the dominant FeS2 phase at Golden Cross, and along with pyrite is shown to have a systematic habit variation. Pyrite shows a sequence from cubes through octahedra to pyritohedra to dendritic growth. This pyrite sequence conforms to an experimentally determined sequence. The parallel sequence for marcasite at Golden Cross is from tabular through bladed aggregates to euhedral miscellaneous marcasite morphologies. The FeS2 sequences observed are believed to be due to increasing temperature, and perhaps also increasing FeS2-oversaturation and fluid flow.

Jan 1, 1994

By M. I. Kalashnikova, Y. M. Shneerson, E. E. Zhmarin, Y. V. Degtiarev, E. M. Vigdorchik

Separation of a magnetic fraction from nickel concentrate following matte flotation, and its treatment in a separate circuit enable reduces precious metals losses. The magnetic fraction is treated in two stages of oxidative leaching: atmospheric and pressure leaching. A study of the atmospheric stage, using mathematical modelling, is described in this paper. The mathematical model and experimental data were used to carry out industrial process calculations. The model enabled extrapolation of the results of batch laboratory test to industrial-scale continuous processing and the selection of optimal process conditions and large-scale equipment. In December 2004, commercial oxidative leaching tests were performed on the magnetic fraction at the Severonickel Plant (Monchegorsk, Russia). A comparative analysis of the mathematical modelling results and the actual process parameters is presented.

Jan 1, 2005

By P. C. McLeod

THE GECO OREBODY, located north of lake Superior in the Thunder Bay district of northern' Ontario, was discovered in 1953. Diamond drilling in the following year indicated a 15,000,000-ton ore-body, and production plans were made for the shipment of copper and zinc concentrates in three years. To accomplish this, the Geco Project was initiated. The property was in an undevdoped, inaccessible area, and the project involved the conversion and extension of a logging road to the property, the construction of two railways and seventy miles of hydro transmission line, the erection of a municipality, the building of a plant, and the development of an underground mine to produce 3,300 tons per day. This paper describes some of the methods used in the underground development phase of the Geco Project.

Jan 1, 1958

By R. H. Grau

This Bureau of Mines report describes methane liberation trends from all U.S. coal mines liberating over 100 Mcfd (100,000 cfd) (2.8 Mm3/d). Detailed are results from the latest Bureau survey performed in 1985 and shown are mine and company name, location, coalbed and methane liberation quantity. The report shows that in 1985, there were 180 mines producing more than 100 Mcfd (2.8 Mm3/d) and the total quantity of methane liberated by these mines was 303,900 Mcfd (8,605 Mm3/d). This data is compared with previous studies performed in 1971 , 1973, 1975, and 1980. From 1971 to 1985, there was a 10% decrease in the number of mines liberating at least 100 Mcfd (2.8 Mm3/d) but there was a dramatic 34% increase of liberations from these mines. The increase seems to be caused by new mines being developed in deeper, gassier coalbeds, particularly in Alabama. Likewise, in comparing the ten highest liberating mines in 1975, 1980, and 1985, an increase in methane liberations each year was experienced. The report classifies mines by three levels of liberations: greater than 100 Mcfd but less than 500 Mcfd (2.8 to 14 Mm3/d); 500 Mcfd to 1 ,000 Mcfd (1 4 to 28 Mm3/d); and greater than 1,000 Mcfd (>28 Mm3/d). It was found that 87% of liberations were from mines producing over 1,000 Mcfd but these accounted for only 38% of all the mines in the study.

Jan 1, 1987

By Xu H.

In recent years, the mineral applications dealing with more complex data in distributed environment have grown rapidly. Many mineral and mining organizations have to organize internally and globally distributed manufacturing and experiment sites, which share the roles of databases and other multi-services like software programs. Thus, there are commercial and technical pressures pushing the mineral software vendors to move their current service toward Web service. XML has gained wide acceptance for representing, storing and transferring structured data and documents of many kinds, especially in scientific communities. However, so far there is no such a Markup Language in mineral industry. A XML-based uniform encoding, which is called MineML(Mineral Markup Language), is proposed and developed in this project. The framework of the MineML specification is created. MineML will play the role as shared protocols within mineral domain for archiving, transferring the multi-nature data between the software packages on the desktop over the Internet and sharing the services between users at different sites. Inspired by MLA’s (Mineral Liberation Analyser, JKMRC, University of Queensland, Australia) Mineralogical Data Presentation Program, a proof-of-concept prototype of Web Service is developed here to validate and demonstrate the MineML specification. Certain strategies, specific technologies and tools are adopted to create such an environment. To accomplish that, a set of experimental MineML documents including correlated XML, XSD (schemas) and XSL(stylesheets) documents have been elaborated for archiving, presenting and transferring the mineralogical data information, with the persistence on flexibility and extensibility for generic mineral and mining data handling.

Jan 1, 2003

By J. W. Halley

RIMMING steels derive their name from their action during solidifica-tion in the molds. As a result of incomplete deoxidation, gas is evolved during freezing, and the metal has a characteristic rolling action. The metal rises along the mold walls and descends in the center of the ingot. This action keeps the top of the ingot open and the advancing rim of solid metal can be seen. The rim grows until the rolling action is insufficient to prevent the top of the ingot from freezing or until the action is stopped by capping the ingot with a heavy plate. The violence of the reaction and its characteristics, such as growth or drop ill the molds, are deter-mined by the Composition, the furnace practice, and the deoxidation in the ladle and in the molds. Though rimming steels represent a large proportion of the amount of plain carbon steel made, they have received comparatively little attention in the technical literature. The manufacture of rimming steels has been described by Hibbard,1,2 Fleming,3 Pierce4 and Jackson.5 The reactions occurring during rimming have been considered from the theoretical point of view by Chipman and Samarin.7 The structure of rimmed-steel ingots has been discussed by Nead and one of the present authors.6 Meyer,8 in studying segregation, investigated the distribution of carbon, sulphur and phosphorus in rimmed-steel ingots by analyzing the rim and core of blooms. In their studies of segregation, the Joint Committee of the Iron and Steel Institute and the British Iron and Steel Federations studied distribution in one billet and one ingot of rimmed steel. A detailed study of the distribution throughout the ingot has not been published. The present investigation was undertaken to determine accu-rately the distribution of carbon, manganese and sulphur in normal rimmed ingots and the general distribution of other common elements present. The study included some work on the effect of pouring condi-tions and furnace practice on the distribution, though there is still much to be done in this direction.

Jan 1, 1938

By J. M. Karpinski

The need for standard test methods in the minerals beneficiation industry is growing with the increasing complexity of our processes and the more stringent requirements imposed on the quality and uniformity of our products. Although solutions of our problems have never been easy, they will become increasingly difficult to achieve unless we can develop a reliable and reproducible set of test methods. Historically speaking, our need was greatest for methods of chemical analysis. As these methods developed, they improved our ability to determine the grade of ore and measure the effect of our beneficiation attempts. The entire concept of grade and recovery is only as old as chemical analysis. Then came physical measurements. Each new concept in minerals beneficiation was related to certain properties and required corresponding test methods: specific density for jigging, magnetic susceptibility for magnetic separation, and tumbler strength for pellets. And associated with each process was the need for size determination. Size measurement is probably the first physical test ever conceived, and yet we are still improving on it. Dry sieving was quite acceptable for direct-shipping ores, but we had to go to wet sieving to control pelletizing and flotation. Subsieve analyzers have extended our routine measurements to the subsieve sizes, hut not below a few microns. As we all know, the solution of slimes- beneficiation and pollution-abatement problems is hampered by the lack of reliable and reproducible test methods in the fine-particle size range.

Jan 1, 1971

By Jan M. Mutmansky

Main purpose of the research described is to apply the method of computer simulation to the process of tunneling by rapid excavation methods. Primary attention was focused on the materials handling subsystem because of its potential for improvement from a systems standpoint. A description is given of the computer model and a summary of some applications of the model for improving the rapid excavation process is included.

Jan 1, 1975

By W. W. West

MACHINERY used for size reduction of materials may be divided into three classes-depending upon the manner in which the crushing force is applied. In the first class could be listed the primary crushing units, such as the jaw crusher and gyratory crusher-which crush to coarse sizes by applying pressure intermittently between converging surfaces. In the second class may be listed crushing units, such as the hammer mill, roller mill, and ball mill, which crush principally by grinding or attrition. In the third class is the impact mill which, as the name infers, crushes by impact. The second and third classes generally include machinery used as secondary units for intermediate or fine crushing and grinding. Theory of Crushing by Impact Throw a stone into the air and give it a severe blow while it is momentarily suspended, and it shatters into several pieces. The impact crusher uses this "batting" principle, but carries it one step further. As the material to be reduced enters the crushing chamber, it receives a severe free-air impact blow by hard-hitting beaters suspended from rotor discs. The shattered particles formed are then driven at high velocity against impact blocks, where a further reduction in particle size takes place. The rebounding particles from the impact blocks are again caught by the beaters, and the process repeated until the material is swept out of the open bottom of the crusher. Impact Crushing Versus Attrition Crushing Fig. 1 shows a Hammermill type of attrition crusher. This particular mill has central feed and is reversible. Because of the central feed, an impact section can be designed into it at the feed entrance for preliminary crushing, followed by the cage bar attrition area for final sizing. The material is caught and held in a crushing chamber enclosed by grate bars or perforated plate. It remains in this chamber until it is reduced to particle size small enough to pass through the openings between the bars or in the plate. In this manner the top particle size discharged from the mill is closely controlled. As the swinging hammers pass through the bed of material, the material is broken down by a scrubbing action between hammers and material, material and grate bars, and material against material. This attrition produces a rounded particle shape, accompanied by slivers and a comparatively high percentage of fines. The crusher is especially useful in industries where the material treated is not too abrasive, such as limestone, cement or coal plants. It can be readily understood that from the maintenance standpoint, it is not suitable for hard abrasive materials such as refractories and aluminum oxides. One common type of impactor is shown in Fig. 2. The bottom of this type crusher is entirely open and the passage of the material through the crushing chamber is almost instantaneous. Liberal clearances are maintained between the impact hammers and the anvil type breaker blocks. This eliminates practically all attrition. It is the elimination of attrition that makes the impactor particularly adaptable for reducing hard, abrasive materials. The impactor is also well suited for the reduction of wet or frozen materials, which clog an ordinary Hammermill. Particles broken by impact, when examined under the microscope, show a distinct tendency toward rough, cubical shape, with a minimum of fines. Another important factor in impact crushing is that crushing is accomplished along natural cleavage lines, thus freeing foreign ores or materials.

Jan 1, 1952

By Robert Morgan

With improved methods for designing and detonating shots the potential for flyrock can be significantly decreased, but there are few absolutes in blasting; therefore blasters must learn from the mistakes of others. Blasters must conscientiously employ control measures to minimize the risk of flyrock. The worst case incidents which tend to be widely reported by the media, should serve as a reminder to us all that minimizing the risk of flyrock must be incorporated into the design of the drill pattern and blast design.

Jan 1, 2001

Jan 1, 1965

By B. B. Zavoico, J. G. H. Crump, P. P. Gregory

West Texas was the scene of greatly increased oil activity during 1937, producing 75,743,000 bb1.l in that year as compared with 61,901,-000 bb1.2 in 1936, an increase of 22.36 per cent. The annual total of wells completed increased from 15863 in 1936 to 28062 in 1937, an increase of 76.92 per cent. Of the total completions in 1937, 2464 were oil wells,2 11 gas wells2 and 331 dry holes.2 The marked increase in the number of oil wells completed in West Texas during 1937 had a substantial effect upon the daily average production per well, which decreased 20.84 per cent from December 1936, when a total of 5310 wells3 produced 5,236,467 bbl.3 for an average of 31.81 bbl. per well per day to December 1937, when 7571 wells2 with a total production of 5,910,257 bb1.2 averaged 25.18 bbl. per well per day. Drilling blocks and checkerboard acreage were being acquired following geophysical work in the northern end of the Permian Basin area, composed of Bailey, Cochran, Hockley, Yoakum and Terry Counties, presaging extension of active development northward. During 1937, at one time 30 geophysical crews were working in West Texas, and an average of 15 to 20 crews was active in this area throughout the year. Discoveries Wasson-Denver Field.—Wasson-Denver field in Gaines and Yoakum Counties was the outstanding field discovery of the year. Production is from porous limestone found at about 5000 ft., and an average well is good for from 300 to 500 bbl. of crude oil per day through 3/4-in. choke. The discovery well was drilled by A. G. Carter and others on the Wasson Ranch, Gaines County, and the field has since been extended into Yoakum County. At the year's end 21 wells had been completed, producing

Jan 1, 1938

By Hong Zhong, Shuai Wang, Zhanfang Cao, Ting Dai

"Manganese is widely used in industries such as the steel industry and is now an essential element in modern industry. Technologies for the efficient and clean utilization of manganese resources must be developed and employed to ensure the sustainable growth of the manganese industry. Our research focuses on the use of beneficiation technologies to improve the grade of ores or the replacement of low-grade manganese carbonate ores with high-grade manganese oxide ores, and thus, to reduce reagent and energy consumption and the yield of electrolytic manganese residues from metallurgical processes; the study of leachate purification technologies; the study of electrochemical behaviors during electrolysis and energy-saving electrolysis methods; the development of chromium-free passivators as alternatives to the highly toxic potassium dichromate passivator; the non-hazardous treatment and resource utilization of electrolytic manganese residues and other manganese by-products; and the development of new manganese products. INTRODUCTION Manganese is widely used in the steel industry, nonferrous metallurgy, the chemical industry, electronics, batteries, agriculture, etc. Globally, more than 90% of manganese is consumed by the steel industry, and thus, it is said that ""No steel industry without manganese""(Banerjee et al. 2017, Zhang et al. 2017). Current manganese resources mainly include manganese ores, marine manganese nodules and waste catalysts. The total global output of manganese ore from land deposits is 18 million tons (metal volume), and the reserves, most of which is in the form of manganese oxide ores, are estimated to be 620 million tons (metal volume). More than 400 manganese ore deposits with a total reserve of 1.22 billion tons have been discovered in China. These deposits are predominantly manganese carbonate ores. Marine manganese nodules exist on the surface of the deep seabed at depths of 2000-6000 m. These nodules, which are also called polymetallic nodules, manganese balls, manganese aggregates and manganese tumors, are mainly composed of iron and manganese oxides. The total reserves of these resources add up to more than 3 trillion tons. Furthermore, the manganese in manganese-containing catalysts can be recycled after they become inactive."

Jan 1, 2018

By Dale E. Berner

A new navigation dam at Olmsted on the Ohio River will be built "in-the-wet" using a lift-in construction method by the Washington Group/Alberici Joint Venture for the U.S. Army Corps of Engineers, Louisville District. Up to 4,000-ton precast concrete dam shell segments will be prefabricated on the Illinois riverbank and lowered into the river on a marine skidway and cradle. A 4,500-ton capacity catamaran crane barge will lift the precast concrete shells and lifting frames from the cradle, and transport them partially submerged to a piled foundation pre-installed underwater. Tremie concrete will be used to compositely connect the shells, piles and sheet pile cut-off walls. This paper focuses on the pipe-pile foundations for this half-mile long navigation dam, and for the temporary precast yard and marine skidway. The dam foundations are designed to resist large ground motions from the New Madrid Fault Zone, and selected production piles are designed to serve as landing piles to support the shells during the construction process. Specific foundation issues addressed in the paper include: pile load tests; production field testing requirements; controlled fixity 24-inch diameter pipe-pile design including seismic considerations; cut-off wall design; sheet pile cellular fixed weir design; isolation jOint design; and temporary works foundation designs for both the precast yard and the marine skidway, including testing of 42-in diameter pipe piles.

May 11, 2007

By C. A. Herbert

"The Workman's Compensation Law of Indiana, enacted in 1915, amended in 1917, 1919, 1923, and 1927, and in 1929 named the Indiana Workmen's Compensation Act of 1929, provides for a weekly compensation for disability due to accidents of 55 per cent of the average weekly wage of the employee, to start on the eighth day of disability. Compensation is computed from a maximum and minimum weekly wage of $30 and $16, respectively. Thus, the maximum weekly compensation is $16.50 and the minimum $8.80; the total compensation paid is not to exceed $5,000.In addition to the compensation the employer is required to pay all medical, surgical, hospital, and nurse fees for a period of 30 days and may be required to pay such fees for an additional 30 days at the direction of the Industrial Board of Indiana. In the case of fatalities the employer must contribute $100 toward funeral expenses.The law also stipulates that ""the employer shall keep a record of all injuries, fatal or otherwise, received by his employees in the course of their employment,"" also that the employer shall report within one week of their occurrence all accidents that cause either the death of the employee or the loss of more than one day's work. However, no standard form is furnished or required by the industrial board on which the employer shall keep a record of accidents, neither is he required to report the time of return to work of the injured employee unless the period of disability exceeds seven days and the accident thus becomes compensable. Hence, no record is kept of noncompensable accidents other than the first report sent to the industrial board by the employer.If the employer were required to keep a complete and concise record of all accidents, in duplicate, on a special form either furnished or required by the board, giving all of the essential data in regard to the accidents, and if he were required to submit a copy of this record to the board at the end of the fiscal year, the data thus assembled would not only be of material assistance to the board, particularly in making up its annual report, but would also furnish information of much value in the study of accident causes and what may be done to remove them.Those industries that have made marked progress in reducing accidents keep such records, as it is only through a full knowledge of how accidents occur that intelligent steps can be taken to prevent their recurrence. Unfortunately, the mining industry as a whole in Indiana has not kept pace with many other industries in reducing accidents, and it is urged as an aid to improvement that a thorough and complete record of mining accidents be kept."

Dec 1, 1932