Search Documents

By B. E. Protheroe, C. Allen, A. Ball

The results of laboratory abrasive and abrasive-corrosive tests carried out on a range of carbon, Iowalloy, and stainless steels are compared with underground tests conducted on similar materials on prototype shaker conveyors carrying gold-bearing quartzitic rock. The dry-abrasion resistance of all the steels was found to be better than that of mild steel. When the added effect of corrosion was tested, the stainless steels proved to be much superior to proprietary abrasion-resistant alloys both in the laboratory and underground. The ferritic stainless grades were shown to be superior on the basis of cost per unit of volume lost. This investigation has shown that laboratory tests on materials can provide valuable information on their possible performance in situ, and can thus be used to replace lengthy experiments on site.

Jan 1, 1981

By K. Shitogiden, Y. Samada, T. Miki

Steelmaking slag contains nutrition such as Si, P and Fe for acceleration of phytoplankton growth. Phytoplankton can fixate carbon dioxide more than any other species on earth. Hence, suppression of CO2 can be achieved by applying the potential of steelmaking slag as the nutrition for their propagation. When it is considered to supply nutrition from steelmaking slag to seawater, we must avoid dissolution of hazardous elements or change of pH of seawater by steelmaking slag addition into seawater. The protection against dissolution of fluorine into artificial seawater has been studied based on dissolution behavior of steelmaking slag and synthesized substances into artificial seawater in the present work. The dissolution mechanism of fluorine from steelmaking slag and buffering action of pH change are discussed by using stability diagram in seawater.

Jan 1, 2004

By R. P. H. Willis

This paper describes the economics of backfilling, hydro-power, and mechanization when they are combined in an integrated stoping system. These three technologies have been shown to be viable, and the mines of the Gold Fields Group are introducing backfilling where the depths exceed approximately 2000 m below surface and in other highly stressed areas. addition, a number of mines are installing hydro-powered systems, and the first trackless stope within the Group may soon be a reality. The main emphasis in the paper is placed on the quantifiable effects of trackless stoping, including a basic risk analysis by use of a spreadsheet model. It is concluded that a substantial decrease in working costs and an increase in revenue are possible, resulting in a marked increase in working profit.

Jan 1, 1989

By Song Ning

The main mineral constituents of phase-transformed chalcopyrite are CuS and FeS2. CuS is more soluble than FeS2 in an acidic CuCl2 solution with presence of excessive NaCl, so that FeS2 could be removed as solid residue from a leached solution. The experimental results showed that the efficiency of the copper leaching is heavily determined by the following two factors: a) The degree of the chalcopyrite phase transformation to CuS and FeS2 b)The concentration of Cl during the leaching, specifically whether there is enough excessive Cl existed. I t was found that when the Cl in the solution is not excessive, the slowest step of the leaching is the dissolution of Cu2Cl2.

Jan 1, 2006

By Jim Daley

SEE is a dynamic organization composed of people from all facets of the explosives industry who are truly interested in the advancement of that industry. I had been a miner at the Homestake Gold Mine in Lead, SD for 12 years when I decided to obtain a mining engineering degree. The mental and economic consequences of that decision were more severe than we had imagined. The joint scholarship program of the Northern Plains and Black Hills Chapters of SEE provides assistance to several college students each year. I was fortunate enough to receive scholarships from this program twice and this assistance helped me and my family with both monetary and psychological support during times of need so that we could stay focused on the goal of obtaining a degree.

Jan 1, 1995

In general, it cannot be assumed that the strength of coal pillars remains constant over long periods of time. Field observations indicate that a coal seam, especially when it contains a parting layer, deteriorates over time, reducing the load-bearing capacity of the pillars. This paper discusses a unique approach to determining the time-dependent strength of coal pillars in the field. Three coal pillars that were developed 5, 15, and 50 years ago were chosen for the study. Holes were drilled in coal and parting layers in each pillar, and the strength profiles were determined for each hole using a borehole penetrometer. The strength data were treated statistically to establish time-dependent strength equations for different layers. The results can be used to help estimate the loss of pillar capacity over time.

Jan 1, 2012

By John V. Beall

Our moment of truth is in the offing. When the SME Directory is published in this July issue of [8:] we will know how good or how bad our system is for this computerized Directory. At this writing we have not seen the printout. The SME Directory is designed for maximum utility by the membership but this, of necessity, makes the job complicated. In the alphabetical section, names are listed last name first, followed by codes indicating the class of membership, year of election and divisional interests of each Member. This information is followed by job title, company division, company name and address complete with zip code, or simply by the mailing address of the Member in cases where he either has no company or has not supplied the company information.

Jan 1, 1971

By W. Mostowitsch, H. O. Hofman

In our investigation of the Behavior of Calcium Sulphate at Elevated Temperatures with Some Fluxes,' we incidentally studied the decomposition of ferric oxide when heated in a current of dry air. We found that at 1,500° C., with 15-min. periods of heating, Fe²,O³, hardly changed in weight, the greatest loss being 0.23 per cent., and we therefore concluded that the compound remained unchanged at 1,500° C. in a current of dry air. In a more recent experiment we heated Fe²,O³, in a current of dry air and found that there was a decided loss in weight. A new investigation upon the behavior of Fe², O³, using a larger amount of substance and heating for a longer period of time, revealed the fact that a measurable dissocia-

Jan 1, 1910

OFFICIAL Washington is gravely concerned over the adverse military situation caused by the all-out intervention of the Chinese Communists in Korea. What the policies of the United Nations and the United States will be in the new crisis is unknown. However, Stuart Symington, chairman of the NSRB, set the general pattern for mobilization in the near future when he said that this country would move from a "light gray to a dark gray mobilization." The implications of accelerated mobilization for the mining industry are particularly apparent with respect to the manpower situation. Revised policies recently initiated for the recall of reservists may be abrogated, in which case key personnel in the mining industry may face calls to active duty with insufficient consideration given to their indispensability to national defense in their present positions.

Jan 1, 1951

By C. A. Rowland, R. C. Nealey

Wet grinding rod mills have been used for 50 years to grind ores and to make specification sand. The application of wet grinding rod mills is well understood. Until recently, there have been very few installations of dry grinding rod mills. The selection of dry grinding rod mills follows the basic principles established for the selection of wet grinding rod mills. The basic Bond Formulae1 [ ] is used to select mills when using grindability test results as the basis for selection. W is multi- plied by the 1.3 wet to dry grinding factor established from wet and dry ball milling experience, and then by any other applicable inefficiency factors.1 Dry grinding rod mills have also been selected by scaling up bench scale continuous rod mill tests and pilot plant tests.

Jan 12, 1968

The early gazetteers mentioned the mining of coal in this state but gave no output data Several of the bulletins of the Illinois Coal Mine Investigations give the results of some historical studies of parts of the state and some early production figures, but some make no mention of this phase of the industry Reports to the state by the various railroads of tonnages carried give figures for coal carried, but usually do not specify its origin These figures, however, when used for roads which crossed the various coal producing counties, and divided between counties in accordance with the little data available have furnished the base for the most of the estimates of county productions Some county histories furnished a few facts, and some were obtained from various other sources

Jan 1, 1942

FOR two days preceding the Colorado Mining Association annual meeting, officers representing all interests of the lead and zinc producers hammered away at remedies for the ills of the industry behind closed doors at the University Club in Denver. For once in the stormy history of the industry, large and small producers alike came to agreement with an automatic sliding scale stabilization import tax. The proposal set forth in full on the following page, is not new being merely an amplification of the tariff arrangement whereby tariffs are imposed when the price drops below ceiling. Its advocates claim that it is simple, automatic, and flexible. It will give stability to the industry without subsidies and since no government bureaus will be required to administer it, there will be no cost to the taxpayer.

Jan 3, 1953

By N Vijay Mohan, K V. Balamukund, G Ananth Ramulu

Jointing of steel rods in reinforced concrete structures needs careful consideration as it renders the structure weak at the joint. The jointing is usually done at sections of structural members, where the bending moment and shear force are least. Jointing is done either by overlapping the rods or welding or by mechanical splicing. A novel method of jointing them is by inserting the two rods in a steel sleeve and cladding it on to the rods by subjecting the sleeve to explosive energy. A rod jointed in this fashion is tested for direct tension and bending when used in a reinforced concrete beam. The test results show that it is an effective method. The advantage is that a number of joints can be made in a single operation.

Jan 1, 1993

Two separate but closely related projects now under construction on the St. Lawrence River- the Seaway and the St. Lawrence Power Project- are providing the impetus for what may become one of the most significant economic expansions in the Northeast. By 1959, or even earlier, electric power will be flowing from the largest single hydroelectric installation east of the Rockies. Simultaneously there will come into existence a great new commercial waterway which will provide cheap transportation from the farm and industrial heartlands of the U. S. and Canada to the markets and resources of the world. When the Seaway is completed, vessels with five to ten times the capacity of those now using the Canadian canal system will be able to move from the Atlantic Ocean to Lake Superior.

Nov 1, 1955

Dragline performance drops considerably when chop-down and double handling of material is needed due to increasing overburden thick- ness or total pit depth. Beyond a certain pit depth the dragline needs support by a pre- stripping system in the upper portion of the overburden. In soft to medium hard ground the bucket wheel excavator can be used for pre- stripping, whereby several methods of material transport are investigated. Conveyor transport around the pit and dumping by stackers is the best solution from the technical point of view. Cross pit transport and dumping by means of a conveying bridge is the method with the lowest costs per volume moved. Cross pit transport by use of a beltwagon with overlong discharge boom is both, poor from the technical point of view and high in overall costs.

Jan 1, 1981

By S. Xu, A. Ramesh, F El-dabbagh, Z. Fang, A. Sobhy, J. A. Kozinski

Waste remediation is a goal that will be driven forward by economic conditions. As the cost of waste disposal increases, new methods of waste reduction will become economically attractive, and will be implemented. It is difficult to imagine, however, a time when there will be no waste generation. For the foreseeable future, despite effective reduction practices, there will still be hundreds of millions of tons of waste that must be destroyed or controlled to protect the public health and the sanctity of the environment. To remain faithful to environmental covenants, the mineral and metallurgical industries will face these new challenges. This paper discusses novel waste remediation approaches and techniques focusing on hazardous wastes and thermal remediation. Aspects concerning technological and environmental importance are examined. Solutions for neutralization of environmentally hazardous compounds are proposed.

Jan 1, 2004

By Owen F. Jensen

CONSTRUCTION of a ground-water supply includes many operations, which do not end with completion of facilities. Evaluations must be made of the quality of water in various areas and the history of production. Following an analysis of geologic, hydrologic, and chemical data there must be an exploratory drilling program and a study of resulting information. When the well is completed a continuous survey of operating records and basic data is necessary, since designs for future wells are varied as more data becomes available for those already completed. As the following discussion must be limited to a single undertaking, the customary procedure will be outlined for development and construction of a ground-water supply in which more than three wells are involved. Parts of this procedure are applicable for all ground-water supplies.

Jan 11, 1954

CLARENCE M. HAIGHT, Franklin, N., J. (communication to the Secretary*).-In that hart of Mr. Wilson's paper describing the Gilman cut-and-fill system, a few features do not appear to be fully explained. In what way is the waste used for filling obtained? The text mentions that, if waste is encountered when driving the filling raises, these raises are stopped until the fill is needed; that seems to suggest mining the capping for fill, which might make the backs of the stopes had as the stopes approach the top of the ore. If, on the other hand, the fill is brought to the raises in cars, are the crosscuts that are necessary in ore or waste? Is the cost of this fill included in the stoping costs given?

Jan 5, 1917

By M. P. Rennick, D. M. Burton

The Murray Brook massive sulfide deposit, which was the first geochemical discovery in the Bathurst camp, is one of the largest sulfide deposits in the area. The massive sulfides are hosted by quartzose metasedimentary rocks in the lower part of the Ordovician Tetagouche Group. This thick succession of sedimentary rocks is overlain conformably by felsic volcanic rocks, and is structurally overlain by mafic volcanic rocks. The massive-sulfide body is polydeformed, but primary metal zoning is still discernable and may permit future exploitation of discrete lead-zinc and copper zones. Although it was discovered in 1956, the deposit was not developed until 1989, when Murray Brook Resources commenced processing of gossan containing precious metals. Recovery of gold, silver, and mercury is accomplished by indoor vat leaching on a year-round basis.

Jan 1, 1992

By Jack F. Havard, John S. Lagarias

When ore bodies are faulted or mill feed turns refractory, mining managers and engineers act vigorously to convert imminent failure into eventual success. The recent proliferation of onerous environmental regulations and restraints is likewise a threat to successful mining enterprise, in some ways more insidious and dangerous than the problems presented by natural obstacles. The regulatory burden has become so heavy that a pall of pessimism covers much of the mining industry. In this paper we frankly recommend an approach that does not just "make the best of it" but rather directs the whole environmental process: first, to improve planning, engineering, and operating procedures; and, second, to demonstrate the need for modification of laws and regulations which are intolerably burdensome to both the mining industry and the public.

Jan 1, 1979