The measurement and prediction of coin wear in circulation

Abstract The circulation wear rates of pure nickel, cupronickel and nickel-plated-steel coins were measured and found to be in the ratio 1:3:1. The relative wear rates of nickel and cupronickel coins were similar to those reported in earlier studies, and the circulation wear data for nickel were used as a reference in laboratory wear tests. A correlation between circulation wear rates and laboratory wear rates formed the basis for a prediction of service life using relief legibility as an 'end of life' criterion. This criterion was determined to be an average surface thickness loss of 12 pm. The surfaces of nickel and Nickel-Bonded-Steel (N-B-S™) coins were observed to harden both in circulation and in the laboratory tests at a rate of approximately 1 VHN/year of actual or simulated service life. It was also observed that the laboratory wear rate of N-B-S coins increased as nickel cladding thickness increased and this effect was attributed to differences in surface hardness.
Wear test results are also reported for the new Canadian dollar coin material which shows a better wear resistance than pure nickel.
Keywords: Wear testing, Coinage, Nickel-bonded steel, Aureate Nickel, Cupronickel, Hardness, Friction.
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Publication: CIM Bulletin
Author(s): J.G. KELLY
Keywords: Underground mining, Mucking, Crushing, Conveying, Scooptrams, Oscilloaders, Equipment.
Issue: 911
Volume: 81
Year: 1988
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Summary: The tax reform process marches on. The December 16, 1987 measures tabled by Finance Minister Michael Wilson represent one more step toward the objective of total reform of Canada's income and sales taxes. While the income tax changes are taking shape, much work still needs to be done on the sales tax side of the coin.
Publication: CIM Bulletin
Author(s): ROBERT B. PARSONS
Issue: 911
Volume: 81
Year: 1988
Text
Summary: A flexible model involving perfect mixers, stagnant zones, plug flow, material bypassing and recycling zones has been developed for interpreting mixing phenomena in mineral processes. The mixing properties are described by the residence time distributions which can be subsequently interpreted by the flexible model. User-friendly computer programs (for IMB-PC or compatible) have been developed for simulation and modelling of RTDs using the proposed model. Seven mineral processing case studies...
Publication: CIM Bulletin
Author(s): C. BAZIN, D. HODOUIN
Keywords: Mineral processing, Modelling, Computer programming, Computer application, Mixers, Residence time distribution, Homogenization.
Issue: 911
Volume: 81
Year: 1988
Text
Summary: Oil has been discovered off Newfoundland in a number of locations on the Grand Banks, the most notable and exciting being in 1979 when Hibernia was discovered. This discovery has brought new challenges to the province as well as to all of Canada. During the seven years* since its discovery, both industry and governments have attempted to define its parameters and to find the most efficient and economical way to develop the field. A number of studies have been completed during the interval and...
Publication: CIM Bulletin
Author(s): R. FLOOD
Keywords: Industrial minerals, Concrete, Platform construction, Hibernia, Oil fields, Drilling equipment, Gravity-based platform, Mineral resources.
Issue: 911
Volume: 81
Year: 1988
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Summary: At the time of this study, the Valley mine was producing 23 000 tonnes of ore per day from a large, low-grade porphyry copper orebody. Sulphide mineralization, principally bornite and chalcopyrite, occurs in a stockwork of quartz veins in one phase of the Guichon Creek batholith. The property was explored from 1967 to 1982, and was placed in production in 1983.
Using a three-parameter lognormal approximation developed by G.F. Raymond at Similkameen and Mount Isa Mines, a geostatistical...
Publication: CIM Bulletin
Author(s): G.F. RAYMOND, W.P. ARMSTRONG
Keywords: Ore reserve estimation, Valley, Copper, Highland Valley, Grade estimates, Kriging, Geostatistics.
Issue: 911
Volume: 81
Year: 1988
Text
Summary: Canada became the world's largest uranium producer in 1984. That leadership position is likely to be maintained for many years into the future because of a firm production base, many undeveloped known deposits with commercial promise, and a large geological potential for new discoveries.
There are some uncertainties on the horizon, principally because of restrictive actions in process within the U.S.A., which are aimed at preserving a deteriorating domestic uranium industry. Should such...
Publication: CIM Bulletin
Author(s): O.J.C. RUNNALLS
Keywords: Uranium, Mineral economics, Energy resources, Nuclear energy, Uranium production.
Issue: 911
Volume: 81
Year: 1988
Text
Summary: Geerite (CuI6S) is a rhombohedral copper sulphide which occurs naturally in epitactic replacement of sphalerite; cell dimensions closely approximate those of the host sphalerite.
Geerite-type structures can be produced by leaching digenite (Cu,sS) in ferric sulphate solutions. X-ray diffraction and electron microprobe studies indicate that eight metastable geerite-type structures can be produced, depending upon the concentration of ferric sulphate solution used and the duration of the leach....
Publication: CIM Bulletin
Author(s): RONALD J. GOBLE, LOWELL S. WHITESIDE, ALI M. GHAZI
Keywords: Mineral processing, Flotat ion, Geerite, Sphalerite, Leaching, Sulphu r, Copper.
Issue: 911
Volume: 81
Year: 1988
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