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By John Hall

THE Fremont test for measuring the energy consumed in breaking a notched bar of steel is not so well known in this country as it deserves to be. The test specimen used in this test is about 3/8 by 1/4 by about 1 1/4 in., notched with a hack saw on the lower side to cause the piece to break at a fixed point. A weight of 10 kg. falling 4 m., and provided with a knife or chisel which strikes the specimen, breaks the test piece by impact. The residual force in the falling weight after it has broken the specimen is recorded by a suitable device, and the difference between the total energy and the residual energy of the weight (in kilogrammeters) is the force consumed in breaking the specimen. An experience of several years with the Fremont testing machine has shown its great value in readily detecting brittleness not revealed by tensile testing or slow bending testing. I this paper it is proposed to discuss (1) the supersensitiveness of the test as applied to cast steel and (2) its value in revealing the effect of heat treatment under certain conditions. .

Jan 7, 1913

By H. Reinhardt, P. Haglund, J. Rydberg, B. Lunden

As legislation to minimize pollution in effluent streams becomes stricter, it is important to treat used acid pickling baths before discharge. This is usually achieved by neutralization of the acids and precipitation of the dissolved metals in such a way that neither acids nor metals can be re-used. A process has been designed and tested on a pilot plant scale to recover both acids and metals from a stainless steel pickling bath leaving only Na2SOs in the effluent. In this process, H2SOr is added to the spent pickling liquor and the recovery of the pickling acids HN03 and HF is achieved by solvent extraction, using TBP in kerosene as the organic solvent. The extracted acids are stripped with water, giving an acid concentration high enough for direct use in the pickling bath. Molybdenum is also extracted by TBP and is recovered in a separate step. The other metals, Fe, Cr and Ni, are precipitated from the raffinate as hydroxides, dried and recycled to the metal process. In evaluating this process, comparative experiments with mixer-settler and pulsed column have been performed. The process described is being considered for use by a Swedish company pickling 70,000 tons per annum of stainless steel.

Jan 1, 1973

Report of President The important fact of the year 1916 is that on July 25 contracts were executed by which the American Society of Civil Engineers because an additional Founder Society and arranged to make its permanent home in our building. The contracts provide for the construction of three additional stories to the building, the American Society to pay the cost tip to $250,000, this being considered equivalent to what each other Founder Society had contributed, the American Society to participate in the original Carnegie gift and have an equal share in the property with each other Founder society. The construction of the addition to the building is under way, $62,525.04 having been expended thereon in 1916. It has been found that, clue to war conditions and the advanced price of materials, the cost of the addition will be $300,000. The founder societies have been requested to assume the extra $50,000, one quarter each. This work is in charge of a Building Committee consisting of H. H. Barnes, Jr., Chairman, E. G. Spilsbury, Charles Warren Hunt and Charles F. Rand. At the request of the Founder Societies, important alterations were made in the lecture halls on the fifth floor of the building to make the same suitable for social functions of the societies. The cost, $6,642.08, was advanced by the United Engineering Society but is to be paid eventually by the Founders. The Library of the civil Engineers is being merged with the Library of the United Engineering. Society and the other founder societies. At the present time the membership of the four founder societies is 29,000 and of associate societies 23,000, so that a total of 52,000 engineers now have their headquarters in our building. The value of the real estate now owned by this Society is $1,647,171.16. This sum will be increased at the end of 1917 by the amount of the cost of the addition to the building.

Jan 3, 1917

By Ramani R. V

There are many important physical phenomena in mine ventilation which involve transient mass and heat transfer processes. These processes have been modeled using differential equations often solved with close form solution. Within the last two decades, many numerical schemes have been devised to solve these mass-transfer problems. Much of this effort has focused on variants of the finite element and finite difference methods. In this paper, the solution of mass transfer models in mine ventilation by finite difference technique is discussed. Specifically, the computational effort and the accuracy of the solution are presented.

Jan 1, 1988

By Frederick Burbridge

The Morning silver-lead-zinc mine of the Federal Mining & Smelting Co. is about 'two miles northwest of Mullan, Ida. The lode is a metasomatic fissure vein. The orebody is approximately 2000 ft. long within the bounds of the property and varies in width from knife edge stringers to 50 ft. It has been developed to a depth of 3600 ft. and stands nearly vertical in Revett quartzite, which .strikes north 65" west. The high-grade veins and lenses are generally mixed with waste (siderite, quartz, and quartzite). The average grade of ore to sorting plant in 1921 was 4 oz. silver per ton, 8.6 per cent. lead, and 4.1 per cent. zinc. Wall rock stands only a short time without timbering. The minimum angle of gravity flow is 45". The ratio of waste sorted out to ore is 6 per cent. No gases are generated underground and temperature has no influence on mining operations. Fresh air is forced down the air raise and up the main shaft. Drifting and Stoping Main drifts 12 ft. wide and 13 ft. high are driven every 200 ft. (vertically) and are connected by raises 125 ft. apart. These raises consist of three compartments (chute, tramway, and timber slide) and are for the purpose of ventilation, access, and hoisting supplies to stopes. Ground is stoped between raises. Chutes are placed every 25 ft. for drawing off ore broken in stopes. Waste for filling is obtained from waste raises off the stope in walls or waste is dumped from the level above down the chute compartment of raises, which is bulkheaded so that waste can be drawn off at any floor as required. Timbering Posts and caps for square sets (varying in diameter from 6 to 24 in.) are cut to length in a sawmill on the surface. No preseratives are used. Timber is taken on a flat car along drifts to a raise nearest the working place and hoisted as required. Practically no timber is salvaged for

Jan 1, 1925

Weekly Capacity ? Current Schedule Rate (198.5 tonnes / hour) X Skip Time (112.7 hours) X Effectiveness (85%) = Weekly Capacity (19,015 tonnes) Capacity Conclusions - Existing hoists optimized are best option for Fraser Morgan (>20M + schedule for other). - Peak will have to be managed. - Critical to have equipment & infrastructure in best possible condition to ensure reliability.

Feb 1, 2008

The estimation of local recoveries, such as the local recovered tonnage of ore and its corresponding grade at a given cutoff grade, is an important problem in a selective mining operation. Multigaussian kriging provides a simple solution to this specific problem. The solution is also complete in the sense that local recoveries are estimated together with their estimation variances. It is thus possible to assess confidence limit intervals on the estimated recoveries. Multigaussian kriging has been applied to the Jerritt Canyon deposit in a most realistic situation. The various steps of the estimation procedure are presented in detail and the potential of the method is demonstrated in view of the results. The obtained results show that the estimated recoveries are in good agreement with the actual recoveries and the actual estimation errors are correctly predicted by the estimation variances. Multigaussian kriging thus appears as a useful and fully operationable tool for the mining industry.

Jan 1, 1986

By Tagawa H

In Japan, geological condition do not only vary in a wide range of strata but are also extremely complex with the existence of faults and aquifers. With respect to rocks, in particular, it is very rare that homogeneous rocks are distributed uniformly. In general, geological conditions are distributed in a wide variety, ranging from earth, sand, soft and medium rocks to hard rocks. Under these geological conditions, when planning of the tunnel construction is to be made out, either blasting method or tunnel boring machines must be selected taking into consideration the geological structures along with the designed tunnel route,' possibility of encountering aquifers, hardness of rocks anticipated and also, the adjacent environ- mental conditions. In the process of select- ing an excavation method,, it is important to make a comparative investigation between the above two methods considering the advantages and disadvantages with regard to the respective operating efficiency, economical efficiency and the conditions and scope of application as well. Furthermore, in addition to these considerations, the recent environmental restriction, which does not allow the blasting in the surroundings of residential areas, must also be taken into account. Because of this, in some cases there is no alternative but to use a static excavation method or a tunneling machine even when these are less efficient than blasting.

Jan 1, 1987

By B. Silliman

THESE ores occur in the Laurentian rocks in the town of Clifton, St. Lawrence County, New York. The Clifton Mining Company have opened these magnetites upon their estate of 23,000 acres, on the waters of the Grasse River, an affluent of the St. Lawrence, which flows for about nine milt",3 across the estate, exposing a section of the formation, and affording ample water-power at numerous points. In approaching this district from De Kalb Junction, upon the Watertown and Ogdensburg Railway, the observer passes from the zone of the specular ores, which abound to a great extent in Jefferson County, across a belt of non-metal-liferous limestones, continuing for some miles intermingled with metamorphic rocks, and gradually giving place to heavy beds of granitic and porphyritic gneiss, the weathered surfaces of which present a gray and rough appearance, from the washing out of the feldspar; leaving the quartz very prominent, and completely disguising the real character of the rock, which, when freshly broken, has a lively reddish appearance from the predominance of flesh-colored and red feldspar. Beds of fine-grained quartzite appear also intercalated in the granitic gneiss. These are the dominating rocks of the magnetite region, but the magnetite is always found, so far as the speaker's observation extended, associated with beds of calcite, carrying hornblende, black and green, biotite, and brown garnet interspersed with yellow and magnetic pyrites. The strike of these rocks is about northeast, and their dip about 40' to 45' southeast

By Carlos Ortiz, Pedro Quispealaya

"En este trabajo se detalla las experiencias de innovación de operaciones en una mina subterránea, logrando una visión profesional remota hacia los operadores de: Locomotoras durante la trayectoria de retroceso, Inspección de piques, el arranque y parada de equipos etc. En todos estos empleamos dispositivos electrónicos versátiles en tamaño, peso, capacidad de almacenamiento en memoria y otras relacionadas a la comunicación digital. En esta oportunidad en especial nos referimos a cámaras de video y transmisores aplicando tecnología inalámbrica."

Sep 1, 2017

Hoisting ropes are constructed of wires and strands positioned helically around the axis. This helical positioning causes that, in the rope loaded at the end with the weight Q, the longitudinal displacement u, axial force P, torsional displacement v and constant torsional moment M are generated. More over, the proper weight of the rope q gives the force acting along the axis of the rope. This force changes its value from 0 at the bottom to qL at the top. This force gives, along its length, a variable torsional moment making the rope rotate. During the movement of the conveyance downwards the falling part of the rope rotates, which makes it untwist on the section up to the half-depth of the shaft and twist on the other half-depth. As the result, the twisting lay of the rope changes increasing in the upward direction and decreasing downwards. The angle of twist of the strands changes in an apposite way. When moving upwards, the uplifted rope does not twist and retains its state of deformation up to the moment when it passes over the pulley. Next, the cycle of untwisting and twisting repeats during the movement of the other conveyance downwards. This phenomenon is known from mining practice. It was also analysed, in the works of Glushko (1966) and Popowicz (1963).

Jan 1, 1995

By Paul Billingsley

The term Boulder batholith was first applied in 1897 by W. H. Weed2 to the extensive mass of granite in western Montana within whose borders occur the ore deposits of Butte. In a general way this was known to extend from Helena on the north to the Highland Mountains near Butte on the south, and to be relatively narrow in its east-west diameter. Its intrusive relations to the surrounding sedimentary rocks, and its probable Tertiary age, were described by Weed, but in many ways his statements, based upon incomplete data, have required revision. Most notable of the errors of this description of the batholith were the failure,3 since corrected, to recognize the intrusive contact of the granite with the capping of andesite, and the complete absence of any reference to the many extensions of the granite beyond the somewhat narrow limits of its largest exposure.

Jan 1, 1915

By Thomas M. Barczak

Longwall roof behavior is characterized by strata displacements in both the face-to-waste (horizontal) and roof-to-f1oor (vertical) direc-tions. The roof support structure provides resistance to this motion by translation of these displacements into vertical and horizontal support loading. Observations indicate that the shield reacts with both a vertical and horizontal force to uniaxial convergence (displacement). However, there are different magnitudes depending on whether the displacement is vertical or horizontal. This makes it possible to use supports as monitors of strata activity and loading. The Bureau of Mines examined this behavior using a linear elastic model of the support structure with two degrees of freedom. Vertical and horizontal load reactions were related to associated displacement actions of the strata. This was done by determining the stiffness of the shield under controlled vertical and horizontal displacement motions in the Bureau's mine roof simulator. This report provides example predictions of strata convergence and isolation of horizontal support loading due to vertical roof convergence using the linear elastic shield model. The report also examines efforts to determine strata behavior by direct measurement of support displacement.

Jan 1, 1987

By S. S. Jenkins Jr.

While the method is seldom used anymore, coyote blasting is an historically interesting way to blast large quantities of rock. It was used extensively in the days before modern fast drills were available and can be very effective in some formations that have a natural breakage pattern. This paper will cover the general principles, some blast design factors and point out several actual blasts including some very large ones.

Jan 1, 2005

By Q. Li, B. Ricks

Over the last several decades mineral concentrate long distance slurry pipelines have been installed and successfully operated. Nearly all were installed via the buried construction method. Their record of depend ability and economy has been well proven. However, these systems operate in regions where seasonal soil frost penetration is shallow or non-existent. In recent years interest in long distance mineral concentrate pipelines in northern cold regions has been increasing. For cold regions one must consider seasonal temperatures and soil frost penetration in order to ensure reliable operations through the year. Herein a case study is developed where heat balance and temperatures for small and large diameter long distance slurry pipelines are compared. The study development is as follows: ?Rheological properties are analysed over range of temperatures from near freezing (4ºC; 39ºF) to relatively very warm (40ºC; 104ºF). ?Then assuming similar climatic conditions, soil properties, and pipeline length, a study is carried out for two pipeline diameters, namely: a small diameter (nominal8 inch; 219.1 mm) and a large diameter (22 inch; 558.8 mm). ?The study focus is on maintaining slurry temperature above freezing throughout the pipeline length by illustrating a decision based on burial depth versus coating the pipeline with insulation.

Jan 1, 2007

By P. D. Bush, E. H. Gates, M. D. Vijayaraghavan, L. F. Engle

The process developed over the last few years by Republic Steel Corporation in conjunction with Colorado School of Mines Research Institute has been used as a basis for the conceptual engineering of full size plants. The paper will cover the equipment design criteria, equipment design itself, and the integration of the complex unit operations. There are unique features of agitation and use of gas media through- out. The paper will provide an illustrative example of the process requirements for a variety of raw material feeds. It will discuss the materials of construction approach required.

Jan 1, 1973

The Matakan Unit of New Ireland, Papua New Guinea is a highly fossiliferous lagoonal deposit containing numerous coal pods and lenses. The unit is strati graphically part of the massive reefal Lelet Limestone of Miocence age. These organic-rich sediments have a high hydrocarbon potential as evident from microscopical observations as well as Rock- Eval pyrolysis data. The coal is varied in regard to dominant macerals, vitrinite being predominant in some parts and pollen and spores present in sufficient proportions to constitute a cannel coal elsewhere. The highly fossiliferous carbo as Rock-Eval pyrolysis data. The coal is varied in regard to dominant macerals, vitrinite being predominant in some parts and pollen and spores present in sufficient proportions to constitute a cannel coal elsewhere. The highly fossiliferous carbonaceous sedimentary rocks associated with the coal are rich in pyrite expressed in the sulphur content (19.7 - 22.8%). A high primary productivity and anoxic sediment pore waters or just above sediment - water interface have given rise to sufficient organic matter accumulations to yield a potential hydrocarbon source rock. Atomic H/C ratios of the coals are between kerogen type III and type II mainly, expressing the mixed nature of the coal and that of the associated sediments is type II. Early generated hydrocarbons (exsudatinite) have formed from pollen exines filling the pollen cavities and in places filling micro- fissures in the surrounding vitrinite.

Jan 1, 1987

By P. K. Sharma

The acidophilic and chemolithotrophic Thiobacillus ferrooxidans bacteria grown in the presence of soluble ferrous ions and solid substrates (sulfur, pyrite and chalcopyrite) as their energy source have been used in the investigations. The cell surfaces are characterised by zeta-potential, contact angle, FT-IR and FT-Raman studies. The adsorption isotherms of the cells on pyrite and chalcopyrite indicate that the adsorption begins on pyrite at a much lower equilibrium cell population than on chalcopyrite. The isotherms tend to level off at a cell adsorption density corresponding to a horizontal monolayer coverage when the geometrical dimensions of the cells are considered. In the presence of cells, the xanthate flotation of pyrite completely depressed, whereas chalcopyrite flotation is unaffected. The results suggest that chalcopyrite can be selectively floated from pyrite, also at a neutral pH region, in the presence of T. ferrooxidans cells.

Jan 1, 1999

By Liu C. H, Juang Y. F

Coal/gas outbursts were one of the rather difficult safety problems faced in the coal mines of this Country, with coal fields characterized by frequent disturbances of folds, faults and pinch-offs. With average mining depth about 500m below surface, several such accidents occurred with up to 500 tonnes of coal outburst. In recent years, after a series of improving countermeasures had been undertaken, gas outburst accidents had been greatly decreased. The characteristics of gas outbursts in Taiwan coal mines include relating to coal petrography, mining depth and the other deformation forces. All these have been investigated, trying to determine the parameter of outbursts under natural conditions. The preventive countermeasures include predicting tests, de-stressing boring in coal seams, the emergency procedures during outbursts and certain improving options.

Jan 1, 1988

By William E. Ford, Edward Salisbury Dana

34. Axial Ratio, Axial Plane. - The crystallographic axes have been defined (Art. 22) as certain lines, usually determined by the symmetry, which are used in the description of the faces of crystals, and in the determination of their position and angular inclination. . With these objects in view, certain lengths of these axes are assumed as units to which the occurring faces are referred.

Jan 1, 1922