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By Aspinall T. O, Bell L. C

Increased awareness and stricter enforcement of regulatory requirements for adequate rehabilitation of surface mining sites has made environmental planning an essential part of strip mine planning. Rehabilitation is site specific and should be based on data which relate to that site. Cost-effective spoil pile design to minimise erosion is an important part of rehabilitation. Spoil pile design is an integral part of strip mine design. QCT Resources Limited has provided a postgraduate scholarship toward research in this area. The controlling factors of spoil pile design are post-mining land use, drainage requirements and degree and rate of erosion. The extent to which mine design is controlled by these factors is determined by regulatory requirements. To plan acceptable rehabilitation programs, erosion processes must be accurately modelled, and a range of erosion prediction models are available. Useful prediction models can be placed in two categories with the first category containing soil loss prediction models which can be used to predict the amount of soil lost from an area over a short or long term basis. Models in this category include the Universal Soil Loss Equation (USLE), Water Erosion Prediction Project (WEPP), Griffith University Erosion and Sedimentation System (GUESS) and Chemical, Runoff and Erosion from Agricultural Management Systems (CREAMS). The second category contains topographic evolution models which give an indication of the long term morphological development of a formed surface subjected to erosion processes. Models in this category include "Topog", Willgoose's Physically Based Catchment Evolution Model and Areal Nonpoint Source Watershed Environment Response Simulation (ANSWERS). The USLE has been used in the agricultural field for soil loss prediction. To apply the equation to mine sites in Central Queensland, it is necessary to understand the factors affecting erosion at the sites. This understanding should allow the variables of the equation to be quantified. The rainfall factor applied in the USLE is independent of engineering design or soil management techniques. The factor of spoil erodibility is dependent on the material's physical and chemical properties and can vary from site to site. In the equation, the topographic factor, cover and management factor and conservation practices factor can be varied by design to reduce erosion on rehabilitated areas.

Jan 1, 1991

By T. Haubold, K. Ortner, T. Jung, D. Roth-Fagaraseanu, C. Mattern

Application of integrally bladed disks (blisks) is of increasing interest in compressors of aero engines. Blisks are preferred due to their potential for size and weight reduction, for increased performance and for reduced manufacturing costs compared to conventionally bladed disks. Erosion of the blisk aerofoils in service reduces engine performance, and can result in short shop visit cycles. This significantly increases the life cycle cost of these components, particular when considering that eroded aerofoils can't be exchanged easily for blisks during refurbishment. Shop visit cycle times can be extended and maintenance costs can be reduced through the application of an effective protective coating. The ongoing development of an erosion resistant coating and deposition process suitable for coating complex blisk geometries is described here. The coating is a multilayered W /TiB2 system exhibiting superior erosion resistance compared to known single- and other multilayer concepts. A modified sputter process is used to enable coating even of blisk geometries with shadowed surface to competitive recurring cost.

Jan 1, 2006

By A. M. F. Carter

A survey was conducted so that the degree of corrosive, erosive, and abrasive attack on material-handling systems in the mining and mineral-processing industry could be assessed, and so that the areas of research and development that would be relevant to the needs of the industry could be determined. Of the 59 different mines that were invited to participate in the survey, 41 returned completed questionnaires, giving a return rate of 70 per cent. The total number of completed questionnaires amounted to 45. An analysis of the results shows that attack by erosion or abrasion is considered to occur more often than attack by corrosion. However, al three types of attack must be regarded as significant problems within the mining industry, since 52 per cent of the participating mines reported pump failures due to the inability of the materials of construction to withstand the operating conditions, and almost 90 per cent reported piping failures due to corrosion (22 per cent) or to erosion and abrasion (78 per cent).

Jan 1, 1986

By Niraj Bala

Boiler tubes of coal-fired boilers suffer severe erosion-corrosion (E-C). One method to counteract this problem is by the use of therma, spray protective coatings. Cold spray coating process was used to deposit Ni-20Cr powder on SA 516 (Grade 70) boiler steel. The bare as wel, as the coated steels were subjected to cyclic experimenta, studies, in the superheater zone of a coa, fired boiler. The weight change technique was used to establish kinetics of the erosion-corrosion. XRD, FE-SEM/EDS and X-ray mapping techniques were used to analyse the as-sprayed and corroded specimens.

Jan 1, 2010

By J. Davis, M. G. Reading

"INTRODUCTIONInternational Minerals and Chemical Corporation (Canada) Limited operates two potash mine/refinery complexes near Esterhazy, Saskatchewan. Annual production of approximately 4.2 million tons is sold in the United States and overseas in five grades according to size and quality.Ore grading 25% K2 0 equivalent is mined from a horizontal bed by continuous boring machines, crushed, and hoisted at 8 inches. The refinery operation consists of the eight basic steps shown in Figure 1. Particle sizes handled are similar to those experienced in other forms of mineral beneficiation: 8 inches to 100 mesh. The ore is crystalline and particles are angular. Fortunately the major mineral constituents, sylvite (KCl) and halite (NaCl), demonstrate relatively low hardness at 2 to 2.5.Therefore, while simple abrasion must be acknowledged, it is not a major problem except, of course, in circuits carrying magnetite.Corrosion, as represented by the classic equations of Figure 2, occurs in all its various forms."

Jan 1, 1983

By I. Iwasaki

The effects of percent solids, mill loading and grinding time on product size distribution and ball wear were studied in a laboratory ball mill for a taconite ore. Mild steel balls and HCLA steel balls were used to examine the role that ball hardness play in grinding. Net production of minus 325 mesh - material reached maximum at 70% solids, whereas the ball wear decreased as pulp density increased. HCLA steel balls ground the taconite ore finer than mild steel balls under otherwise identical conditions. Examination of ball surfaces with a scanning electron microscope suggested that grinding with mild steel balls involved nipping rather than attrition, whereas grinding with harder HCLA balls involved both nipping and attrition.

Jan 1, 1984

By Paulo F. T. Sachs

ERP systems have been widely implemented nowadays in several industries. However, ERP was originally designed to fit former MRP and MRP II users, and most of the ERP research has been focused on discrete manufacturing . On the other hand, process industries ? and mining in particular ? present many peculiar characteristics, which are difficult to comply with ERP systems standard functionalities. Again, very limited research has been developed covering enterprise management systems in mining. The objective of this paper is to identify, through an explanatory study that includes a case study methodology, how ERP systems manage the functional areas of the mining industry, and how they fit into the mineral value chain IT requirements. A secondary objective is to identify the gaps between ERP?s functional capabilities and the mining industry business requirements, and to point out the perceived benefits they generate to the companies.

May 1, 2004

Jan 1, 1967

The following errors were inadvertently included in "How millisecond delay periods may enhance or reduce blast vibration effects" by R.M. Wheeler in the September issue of Mining Engineering.

Jan 1, 1987

Jan 1, 1910

Jan 1, 1969

[VOL. XXXVI. Page. Line. 155 29 For "Joachimstahl," read "Joachimsthal." 215 Foot-note 2. For " May, 1892," read " May, 1902." 216 21 For " ack-screw," read " jack-screw." VOL. XXXVII. 31 3 For "quantity of tons," read "quantity of slimes." 35 10 Expunge "recorded in Table VII." 37 24 Expunge "to." 38 33 For "page 89," read "page 9." 44 40 For "page 86," read "page 6." 47 In table, third line under heading "Excavators and Conveyors," expunge "per 40 ft. of."]

Jan 1, 1918

By A. J. Partos

Table 4, Page 311 Table 4 Experimental Parameters from Straight Line Interpretation of Mohr Failure Envelope [ ]

Jan 1, 1991

Most statistical and geostatistical methods of re-source and reserve estimation work extremely well for Normal (Gaussian) well-behaved information. However, most interesting mineral deposits exhibit far from this idealistic distribution of values. It seems that the more valuable the mineral, the less likely the data are to have a Normal distribution. Values tend to be "positively skewed" with a long tail into the high values. Using averaging techniques, such as inverse distance or ordinary kriging may result in consider-able overestimation of grades and tonnages unless such values are cut or otherwise modified. This paper presents some real case studies where distributions are (a) highly skewed and (b) the product of multiple phases of mineralisation. Practical methods are presented for solving such problems including combinations of indicator and log normal kriging methods. The emphasis of the presentation is on developing operational methods which can be used on project evaluation or grade control in producing mines.

Jan 1, 2000

By A T. Spathis

Corrections are given for “A three parameter rock fragmentation distribution” by A.T. Spathis (Measurement and Analysis of Blast Fragmentation, Workshop hosted by 10th International Symposium on Rock Fragmentation by Blasting, New Delhi, India, November 25-29, 2012 pp. 73-86). Typographical errors in two equations for the uniformity index in the two versions of the original and modified Kuz-Ram model are corrected. It is noted that the modified equation in the original published paper of Cunningham also had the same typographical error. A corrected plot of the dependence of the uniformity index versus the burden to diameter ratio is given. These corrections do not affect the rest of the original published paper.

Jan 1, 2013

By William C. Martin

"Consolidated Sudbury Basin Mines Limited owns two mines, 4 miles apart, near the southwest end of Sudbury Basin. The Errington mine lies close to the north boundary of Creighton Township and about 18 miles by car from Sudbury. The Vermilion Lake mine is in Fairbank Township, on the south side of Vermilion Lake.The first discovery of base-metal mineralization within Sudbury basin was made by James Stobie in 1897 at Stobie Falls on the Vermilion River, half a mile west of the Errington mine. A few years later Alphonse Oilier made a discovery of massive pyrite with base-metal sulphides near the west end of the present Errington workings.No work of consequence was done on these discoveries until 1924, when Joseph Errington acquired options on a large acreage of ground which was later taken over by the Treadwell Yukon Company Limited. After considerable diamond drilling this company sank No. 1 shaft in 1926. In the next three years, a large amount of underground development was done, a pilot mill was constructed and operated for two years. All operations ceased in 1931 with the fall in metal prices. While in operation the pilot mill treated 186,172 tons of ore the average grade of which was 1·07 per cent copper; 1 10 per cent lead; 4·60 per cent zinc; 0·03 ounces gold; and 1 70 ounces silver.Up to the time of closing in 193 l there had been completed at the mine 26, 790 feet of lateral work and 75,500 feet of surface and underground diamond drilling. The company records, however, showed no figures on ore reserves, except broken ore in stopes amounting to about 60,000 tons. A study of the plans, prior to reopening the mine in 1952, showed 1,450 lineal feet of ore (at 1952 prices) opened up by drifting on the 300-foot and 500- foot levels. It is clear that no comprehensive picture of the structure was had at this time. The orebodies were considered to be very irregular pods scattered through masses of quartzite-carbonate in a sheared zone about 800 feet wide. In some way the ore was believed to be related to the tuff-slate contact zone. With this picture it was impossible to make a reasonable ore estimate or even gauge the tonnage potentialities with any feeling of reliability."

Jan 1, 1949