Search Documents

By William L. Saunders

MANY members of the Institute, who participated in the visit made, during the Bethlehem meeting of February, 1906, to the shops of the Ingersoll-Rand Company, at Phillipsburg, N. J., inspected with interest the new Electric-Air drill, which the company had set up for the purpose of showing it in actual operation to American. mining engineers. At the request of the Secretary of the Institute, I promised at that time to prepare a paper for our Transactions, describing the construction and advantages of the machine. But such a paper would then necessarily have contained much that was only expected or claimed by the designers and manufacturers of the drill, and not yet incontrovertibly proved by varied and long-continued practice. However moderate such statements might have been, they would have given inevitably to the paper, to some extent at least, the air of a prospectus, rather than of a technical contribution. I therefore decided, with the Secretary's approval, to postpone the writing of the promised paper until it could set forth the results of adequate actual practice, as well as the latest details of construction, etc., based upon practical experience. That period has now arrived. The Electric-Air drill has been exhaustively tested in the field, under varied and arduous conditions and upon the hardest rocks. It is now fairly in the field; its merits and performances are matters of unimpeachable record, and its place among established competitors can be definitely determined. As a representative of the Ingersoll-Rand Co., as well as a member of the Institute, I may be permitted to add that my company, being largely interested in the manufacture of air-

Jan 9, 1907

By A. A. Sadegh

A laboratory investigation was carried out on the characterization and beneficiation of sillimanite ore. Petrographic analysis indicated that the ore consisted of massive elongated sillimanite grains in a matrix of hematite, garnet, feldspar and silica. A procedure for estimating the percentage of sillimanite was developed using float-sink and magnetic-separation techniques. A liberation study was carried out to determine the level of size reduction required to achieve sufficient liberation while ensuring that gravity concentration techniques would be applicable. Laboratory testing was performed on the liberated ore to investigate the applicability of using wide-angle dense-medium cycloning to upgrade this ore. Initially, medium-only tests were carried out using various size distributions of magnetite and ferrosilicon as the dense-medium solids to evaluate the effects of operating conditions on medium segregation. Depending on the medium solids and operating conditions, either positive of negative differentials (difference between the relative densities of the underflow and overflow streams) were obtained. Based on these results, separation tests were performed to process nominal -1.2-mm sillimanite ore. The results indicated that sillimanite concentration could be obtained using a medium relative density that was much lower than would typically be used in a dense-medium cyclone separation.

Jan 1, 2007

MR. RIGG: Gentlemen, I would like to welcome you all to the symposium this morning. My name is Jack Rigg, and I m a special assistant to Hollis Dole, Assistant Secretary of the Interior for Mineral Resources. Hollis is not in town this morning, and I am here to pinch-hit for him. The first order of business this morning is remarks by the Honorable Russell Train, Under Secretary of the Department of Interior. Mr. Train. MR. TRAIN: Thank you, Mr. Rigg. Lest you think that Hollis Dole is not interested in this symposium, let me just say that fie is flying back from Australia just to be here. He is heading up a United States delegation in Australia meeting on resource problems in the Pacific. And I believe he will be here about noon.

Jan 1, 1970

By O. C. Blade

This report on the properties of aviation gasolines and aviation jet fuels produced in the United States during 1955 was made under a co-operative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. Analytical data are presented for 116 samples of aviation gasoline and for 38 samples of aviation jet fuel. The analyses were made on samples typical of the manufacturers' 1955 production in their laboratories and the results submitted to the Bureau of Mines for compilation. The products of 20 manufacturers of aviation gasolines and of 16 producers of aviation jet fuels are represented.

Jan 1, 1956

By Joseph A. Corgan

The river- or dredge-coal industry of Pennsylvania is conducted on many of the rivers and creeks that drain the Pennsylvania anthracite fields. Coal thus recovered found its way into the streams as coal was being prepared for market by the anthracite industry proper, in the northeastern part of the State. The Principal rivers draining; the fields, those where dredging is taking place, are the Susquehanna, Schuylkill, and Lehigh. Several creeks - the Shamokin, Mahanoy, Wiconisco, and Swatara - also are productive sources of river or creek coal. Operations along the streams cover a wide territory, and along the Susquchanna alone; dredges are recovering coal for about 160 miles. Anthracite was a significant factor in the early industrial development of the United States. Industry used it to generate steam, and railroads used it as fuel for locomotives; but it probably was most important industrially in the smelting of iron ore. For more than a hundred years homes have been heated with this fuel. From the beginning of mining in 1807, to 1940, more than 4 billion net tons of anthracite had been prepared and shipped to market. In the preparation process much of the smaller-size coal and refuse found their way into rivers and creeks which carried the material many miles. This study is concerned with the recovery of that anthracite from those rivers and creeks.

Jan 1, 1942

By Mario Aiezza

This paper outlines the results of a relationship developed during the design and construction of the foundations for the Gallery Towers project in Melbourne. Both the builder and the piling contractor were determined to arrive at a satisfactory foundation solution to the problems encountered at the site. The scope of piling work was to provide load-bearing piles under the building columns, some of which were located within a retention system that also required a piling solution. Geological conditions were variable and challenging. The site area was small and located adjacent to the National Arts Centre in the developed Southbank area, a high density office area. This presented logistical problems in limiting construction traffic on site and also demanding minimal noise and vibration emanating from piling activities. The piling contractor, Vibro-Pile, and the builder, Walter Construction Group, faced the challenges presented with a refreshing cooperative attitude that was beneficial to both companies. Commercial issues rising from design and construction problems were first put apart in order to allow the respective technical department of each company to work with minimum constraints to achieve the most cost effective solution. In the process usual adversarial attitudes resulting in loss of time and money was avoided. A number of issues were addressed successfully at minimum cost and time during this contract. Despite the difficulties encountered, the job was completed on time and with negligible claims for extras, resulting in the development of a strong mutual respect between both companies.

Jan 1, 2002

By Yves Gratton

The International Commission on Large Dams (ICOLD) is a non-governmental International Organization which provides a forum for the exchange of knowledge and experience in dam engineering. It is the world's leading professional organization dedicated to advancing the technology of dam engineering and supporting socially and environmentally responsible development and management of the world's water resources. ICOLD was founded in 1928 and has National Committees in 82 countries with approximately 7,000 individual members who are engineers, geologists and scientists from governmental and private organizations, consulting firms universities, laboratories and construction companies. Its original aim was to encourage progession in planning, design, construction, operation and maintenance of large dams and associated civil works by collecting and disseminating relevant information and by studying related technical questions. Since the late sixties, focus was put on subjects of current concern such as dam safety, monitoring of performance, reanalysis of older dams and spillways, effects of ageing and environmental impacts. More recently, additional subjects have included cost studies at the planning and construction stages, harnessing international rivers, information for the public at large, and financing.

May 1, 2002

By Bhaskar B. Thapa

The proposed Caldecott fourth bore will consist of a two lane highway tunnel along California State Route 24 near the City of Oakland. The proposed design and construction sequence for the 15-m-diameter tunnel are based on the New Austrian Tunneling Method (NATM). The initial support system incorporates combinations of shotcrete, rock dowels, lattice girders, spiles, and grouted steel pipe canopies. The final lining is cast-in-place reinforced concrete. A waterproofing membrane and drainage system are placed between the initial and final linings. State Route 24 is a lifeline route, required to be open to emergency vehicles within 72 hours after a major earthquake, defined as having a return period of 1,500 years and a peak ground acceleration of 1.2 g. Although the seismic design criteria are stringent, the design of the tunnel lining system is ultimately controlled by static ground loads in the weak rock along the alignment.

Jan 1, 2008

By T N. Little

The grade control process undertaken at mines aims to maximise the value of the ore (valuable product) mined and fed downstream for processing or sale. The full range of grade control activities includes: reserve estimating, drilling/sampling, assaying, modelling, ore block design, blasting, ore mark out, excavating, stockpiling, processing and reconciling. Over the last 25 years, the grade control process has undergone significant improvements and this is in part due to the developments in grade control blasting. This paper discusses the development and classification of grade control blasting applications in surface mining. A review by the author in 1988 (Little and van Rooyen, 1988) is used as a benchmark for discussing the very significant progress that has been made.Two major technology initiatives have enabled this development. The first was the development of a method for the measurement and analysis of total displacement during the blasting process. Currently, the Blast Movement Monitor (BMM®) is a practical tool that has been used around the world to improve the industry’s understanding of three-dimensional blast movement dynamics. The second technological enabler was the development of electronic detonator systems. The unique aspects of electronic detonating systems are their higher accuracy and that all detonators are activated at time zero (initiation). From a grade control blasting perspective these features and other improvements allow experimentation and, ultimately, more complex, multiobjective blasts to be designed and implemented.This paper reports on a classification and review study undertaken by the author. In all, five selective blasting methods and nine bulk blasting methods are classified and reviewed. Five important observations are made: there is value in classifying the range of grade control blasting strategies, and the blasting objective framework presented is helpful in this regard the range of strategies available to designers is increasing as enabling technology develops, so too do the ambitions of blast designers and the expectations of downstream customersgrade control blasting and Mine to Mill concepts are merging, and this paper caters for this trend using multiple blasting objectiveshaving a technical primary blasting objectives framework, combined with the classification system presented here, should assist practitioners and stakeholders with lateral thinking in regards to future technological innovations, grade control blasting and Mine to Mill initiatives.CITATION:Little, T N, 2015. Classification and development in grade control blasting for surface mines, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 343–354 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Paul J. Sylvester, Yeonuk Choi, Mike Nelson, Louis J. Cabri, Mike Tubrett

"The development and characterization of sulphide standards containing as many as seven precious metals has increased the efficiency and comprehensiveness of micro-analyses for deportment studies using laser ablation microprobe inductively coupled plasma mass spectrometry (LAM-ICPMS). Because trace precious metals occurring in solid solution or as sub-micron inclusions in sulphides, arsenides, and sulpharsenides are often heterogeneously distributed, a significantly large number of analyses are required. Using well-prepared samples it is possible for up to 120 analyses per day, far more than by other comparable methods. Examples will be discussed from projects focused on the deportment of Au and the platinum group elements (PGE).INTRODUCTIONBecause gold and the platinum-group elements (PGE) occur as both discrete minerals and in trace quantities in a variety of minerals (mostly sulphide, arsenide, and sulpharsenide minerals), specialized trace analytical methods were developed and applied to determine the deportment of precious metals in ore deposits, requiring sensitivities ranging originally from about hundreds to presently tens of ppb for individual precious metal or less.In mineralogical studies, micro-analytical techniques such as the electron microprobe were first applied to obtain analyses for major elements in about 1959-60, but as the instrumentation improved early attempts for PGE in potential carrier minerals indicated that reasonable levels of detection (LOD) were of the order of 300-400 ppm, depending on analytical conditions, X-ray spectral lines, and mineral matrix (e.g., Cabri and Laflamme, 1976). Eventually, the lowest detection levels by electron probe micro-analyses (EPMA) obtained for some PGE were of the order of 10s of ppm using high accelerating voltage and current for extended measuring time on peak and background (Gervilla, Cabri, Kojonen, Oberthür, Weiser, Johanson, Sie, Campbell, Teesdale and Laflamme, 2004)."

Jan 1, 2010

By Brosnan J. G

Simcoa Operations is the only silicon smelter in the region and since the plant was commissioned in late-1989, has progressed from supplying silicon metal to the secondary aluminium market to the current position of supplying in excess of 90 per cent of its production to the high quality chemical and primary aluminium markets. This position has been achieved through the unique advantage which Simcoa has developed within the industry, namely raw materials, people and Simcoa's ability to adopt and use modern technology. A quality culture was instilled into the workforce prior to commissioning which ultimately led to AS3902 qualification in 1992. Simcoa has continued its quality drive through the formation of 'Simcoa's Quality Leadership Process' which is planned to make Simcoa the best silicon producer in the world.

Jan 1, 1995

By S. Junnikkala, K. Föhr

"Experiments were performed with plant feeds with a continuous 1,8 m3 cell at Pyhasalmi mine with Cu flotation feed in order to test the applicability of the bubble surface area flux as an indicator of the flotation rate constant. It was found that bubble surface area flux could not predict the rate constants of coarse Cu containing fractions. In the middle size fraction, the correlation coefficient in the rate coefficient estimation was higher but not statistically significant. Only the fine fraction showed a linear relationship with a moderate correlation coefficient.The bubble surface area flux was shown not to be a function of the impeller velocity above a threshold value. The flux was an almost linear function of the superficial gas rate enabling to use the superficial gas rate instead of flux if the operation of an existing cell is to be estimated.INTRODUCTIONBubble area flux seems to offer a simple way of modeling flotation. It relates the flotation rate constant with the bubble surface area flux by a simple linear equation. Due to this, there has been a considerable interest in using the bubble area flux for flotation computations. It has even caused claims that a cell producing a high bubble surface area flux automatically produces a high rate constant and therefore a high recovery.This paper discusses some of the assumptions of the relationship and gives some plant results during two sampling campaigns.The bubble surface area flux s b is describing the area of bubbles available for flotation in a cell per unit area. The bubble surface area flux is related to the superficial gas rate J, by the Sauter mean diameter as follows"

Jan 1, 2001

By J. P. BONARDI, C. W. Davis, R. B. Moore, J. W. MARDEN, S. C. Lind, J. E. Conley

The rare metals are becoming increasingly important to our industries. Rare-metal alloys have properties which indicate that we are only on the threshold of the possibilities of their utilization, not only in making nonferrous alloys, but also as special steels. Not only are their uses broadening rapidly, but the metals are affecting our industries in other ways. The oxides and some salts are used as pigments; others have medicinal value. The pure metals are made into filaments for incandescent lamps, and targets for X-ray tubes. By their efficient use in alloys, the weight of automobiles is reduced, • and the wear and tear on tires and roads is thus minimized; in machine shops they help to give greater efficiency to tools and reduce production costs. Their development has marked a milestone in the progress of civilization. There has been considerable uncertainty regarding analytical methods for the rare metals. A great deal has been published, but the weak and the strong points of the various methods have not been investigated as carefully as is needed. The Bureau of Mines at its Rare Metals station in Colorado necessarily had to do a great deal of analytical work in connection with the metals covered by this bulletin, which aims to give the results of the experience so acquired. No claim for much originality is made, although some published methods given have been modified, and some new ones have been developed by members of the staff. The principal methods available were studied critically, and it is to be hoped that the work will assist those interested in analytical work in connection with the metals named.

Jan 1, 1923

Claims of 16 gold mining companies seeking damages from L-208 will be heard in Court of Claims starting Jan. 26. Earlier this year, judges ruled that 3 gold mining companies could sue for damages from the wartime order closing their mines. Congress later waived the statute of limitations thus permitting other gold miners to get in their claims. Despite power shortages third quarter production of aluminum exceeded that of the previous period by 2.2 pct. However, September production was 16 million lb less than in August. Hewitt-Robbins, Inc. dedicated a new $1 million addition to the company's Buffalo, N. Y. belt conveyor plant. New equipment, including a $220,000 press, will make belts up to 70 in, wide, compared with the former limit of 60 in. Charges of a tin cartel in Malaya are not backed up in the latest U. S. Government report according to the Malayan Tin Bureau. The U. S. mission reported that it "did not discover any evidence of curtailment of tin output by the mining and smelting industries." It noted that guerilla activity had halted exploration and expansion attempts by producers.

Jan 1, 1952

By K. Leutwyler, H. L. Bigelow

Jan 1, 1966

By Freeman Bishop

More than a few discussions are taking place these days among management economists seeking a way out of the dilemma of lower productivity vs. higher labor costs. Most suggestions would be illegal under present antitrust laws. Otherwise interindustry cooperation could be used to divide up some of management's tasks. Or price structures might be tuned to the special machinery and skills of some plants. Both remedies would be under attack almost immediately. There is one other remedy that is getting lots of attention: some form of compromise between management and labor to phase out no longer needed work practices that unions insist shall be retained. Railroads are the national industry suffering the most from this disease, still known as "featherbedding," an epithet coined by the railroaders themselves.

Jan 1, 1971

By R. A. Reiley

Introduction Democratic countries are founded on the principle that all citizens have the right to participate in policy setting and decision-making processes. Citizen participation is especially evident in environmental issues and policies. In the United States, there are currently over 10,000 environmental organizations and new ones are being formed each year. Many of these organizations are formed on a watershed basis and are particularly concerned about the impact mining has on the environment. While the environmental issues vary from area to area, most concerns center around mining impacts related to subsidence, water pollution, and water diversion. Citizens have a number of avenues for participating in lawmaking that affects the mining industry. Some of these avenues include participation in litigation and citizen ballot initiatives. In addition, there are less formal methods of participation that include attending public meetings, commenting on agency rules or lobbying on specific legislation. The intent of this article is outline the various public participations mechanisms, highlight the latest legal developments that have affected mining industry through citizen participation, and briefly discuss emerging issues.

Jan 1, 2001

By S. R. Dindarloo

Although blasting is one of the most widely used methods for rock fragmentation, it has a major disadvantage in that it causes adjacent ground vibrations. Excessive ground vibrations can cause a wide range of problems, from nearby residents complaining to ecological damage. Prediction of blast-induced ground vibration is essential for evaluating and controlling the many adverse consequences of surface blasting. Since there are several effective variables with highly nonlinear interactions, no comprehensive model of blast-induced vibrations is available. In this study, the support vector machine (SMV) algorithm was employed for prediction of the peak particle velocity (PPV) induced by blasting at a surface mine. Twelve input variables in three categories of rock mass, blast pattern, and explosives were used for prediction of the PPV at different distances from the blast face. The results of 100 experiments were used for model-building, and 20 for testing. A high coefficient of determination with low mean absolute percentage error (MAPE) was achieved, which demonstrates the suitability of the algorithm in this case. The very high accuracy of prediction and fast computation are the two major advantages of the method. Although the case study was for a large surface mining operation, the methodology is applicable to all other surface blasting projects that involve a similar procedure.

Jan 1, 2015

By Albert H. Fay

Through the hearty cooperation of the State coal-mine inspectors, the bureau is able to present in this paper a a complete statement of the coal-mine fatalities occurring throughout the United States during the calendar year 1919. The reports received from the inspectors for the year just closed show a reduction of 10.58 per cent in coal-mine fatalities as compared. with 1918, while in 1918 the reduction was 4.3 per cent from 1917 figures. The total number killed was 2,307 in 1919 and 2,580 in 1918, a reduction of 273. There was a decrease of 128, or 25 per cent, in fa tali ties resulting from mine cars and locomotives, and a decrease of 198, or 15 per cent, in the fa tali ties due to fall of coal or rock. Surface accidents show a decline of about 25 per cent as compared with the previous year. There were, however, increases in accidents due to gas and dust explosions and also explosives. There occurred during the year nine disasters in which five or more men were killed, representing a total of 201 fatalities. The worst disaster of the year was the one occurring at the Baltimore Tunnel No. 2, Wilkes-Barre, Pa., resulting from the explosion or burning of a number of kegs of powder, by which 92 lives were lost. This disaster emphasizes the need for stricter regulations relating to hauling men and explosives into the mine at the same time. The question of whether electricity was responsible or not does not affect the consideration of the various dangers which arise in underground transportation and handling of explosiveB. At best the handling and hauling of explo.sives is hazardous and such being the case, no one, other than the necessary attendants, should be permitted to ride in cars or cages transporting explosives. As a result of this disaster, the report b of the coroner's jury to the governor of Pennsylvania brings out some important dangers to be avoided in the use and transportation of explosives.

Jan 1, 1920

By Christoph Müller

Information exchange for mine process optimization is essential. Today, modern mining equipment uses the IREDES standard to exchange production plans and reports for easy management and storage. To gain further benefits from process optimization, a mine wide access to real-time information is needed as e.g.: The current status of a machine, operational details etc. Presently, real-time data exchange systems are developed by machine producers. Each machine producer uses its own way of gathering, managing, and storing production data. These proprietary mining processes increase the complexity of cross platform data exchange and management for mines which involves machines produced by different vendors. Casting and unifying the data requires much effort. For this purpose, ?IREDES On-line? currently is being introduced. The standard defines an open, web based method for the exchange of volatile real time machine information. Two different principles are used: Web Services for cross platform information exchange within the IT world and the optional OPC UA for use with automation and process control systems. With such a standard information from machines of different vendors may be managed by using one common platform without spending the effort for dedicated interface development. Additionally, information management and storage will become straight forward since all the data are of the same format. The IREDES On-line standard utilizes the latest IT technologies as well as the knowledge and experiences gained from the previous IREDES standard. The paper explains the benefits, the use, as well as the technical design of the standard and gives application examples from the practice.

Oct 1, 2009