{"title":"STATISTICAL QUALITY CONTROL: A MULTIVARIATE APPROACH","authors":"B. Samanta, A. Bhattacherjee","doi":"10.1142/S0950609899000232","DOIUrl":"https://doi.org/10.1142/S0950609899000232","url":null,"abstract":"Many quality control operations in mining deal in controlling more than one variable for meeting the quality specifications. In such cases, an application of the Shewhart's univariate control chart for each of the variables is unsatisfactory as it fails to consider the problem in a multivariate situation ignoring correlation structures amongst the variables. In this paper, an application of the Hotelling's multivariate control chart is demonstrated in an iron ore mine through a case study. The study revealed that the sensitivity of detecting an out-of-control condition is increased using a multivariate control chart. It is suggested that once an out-of-control is detected in multivariate chart, the corresponding univariate control charts should be investigated to identify which variable(s) causes the out-of-control condition. While investigating multivariate and univariate control charts for the case study mine, two possible out of control conditions were encountered: one due to the out-of-control condition of the individual variables and the other relates to the correlation structure of the variables. For the case study mine, it was also revealed that even if the application of control charts will improve the quality of ore, it is difficult to meet all the quality specifications, especially Fe% and Al2O3% on a regular basis. To overcome this problem, it is suggested that the system may require a fundamental change in the mining process or the specification limits may be reviewed. The fundamental change may be the review of cut-off grade, changing of blending ratio of material from different faces and further blending of material.","PeriodicalId":195550,"journal":{"name":"Mineral Resources Engineering","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117138745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"AN APPLICATION OF LOGIT MODEL TO INJURY EXPERIENCE DATA","authors":"J. Maiti, A. Bhattacherjee, U. C. Gupta, S. Ray","doi":"10.1142/S0950609899000244","DOIUrl":"https://doi.org/10.1142/S0950609899000244","url":null,"abstract":"The influence of various casual factors on the severity of injury was examined using the 4-year injury data from a group of underground coal mines. Although there are many factors that could affect the injury severity: miners' age, experience, occupation, injury-location, shift-time and specific-mine were chosen as the affecting variables. The logit model was applied for this analysis. The bivariate analysis was conducted to separately study the effect of each of the factors on the severity of injury and to estimate the odds of severe injuries. For the case study mines, it was concluded that the injury severity varies by age, occupation, injury-location, shift-time and specific-mine. However, experience in general does not have any significant effect on it.","PeriodicalId":195550,"journal":{"name":"Mineral Resources Engineering","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125537369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ECONOMIC SIGNIFICANCE OF SUB-CUTOFF GRADES IN OPEN PITS OPERATING WITH CONCENTRATOR BOTTLENECK","authors":"Ren-yi Yi, J. Sturgul","doi":"10.1142/S0950609899000219","DOIUrl":"https://doi.org/10.1142/S0950609899000219","url":null,"abstract":"Mathematical models are built and a nonlinear algorithm is coded to determine solutions to cutoff grade, sub-cutoff grade and sub-grade stockpile sizes which optimise the open pit mining from an economic point of view. The purpose is to study the theory that it is more reasonable economically for an open pit mine to stockpile its low grade ores and treat them later, especially if the mine has a bottleneck condition at the concentrator.","PeriodicalId":195550,"journal":{"name":"Mineral Resources Engineering","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128421933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"EVALUATION OF IN SITU LEACHING PROCESSES: DUAL-POROSITY MODEL","authors":"Jishan Liu, B. Brady","doi":"10.1142/S0950609899000220","DOIUrl":"https://doi.org/10.1142/S0950609899000220","url":null,"abstract":"A dual-porosity model is developed to study processes of in situ leaching. The model involves two overlaying continua at the macroscopic level: a permeable fracture system that determines the flow field of leach solution and a relatively impermeable matrix system that determines the leaching kinetics. The most obvious advantage of the model is that parameters it requires are minimal and easily available in practice. These parameters include the in situ hydraulic conductivity, longitudinal and transverse dispersivities, the lumped rate constant, and an empirical rock mass classification index, RQD (Rock Quality Designation). The simulation of in situ leaching processes is linked to RQD through the effective porosity of fractured media. The incorporation of RQD enables the simulation of in situ leaching processes to be carried out for a whole spectrum of ore deposits. When RQD approaches 0, it represents that the ore deposit may be a porous medium with a high effective porosity. This may reduce the double-porosity model to a single porosity model. When RQD approaches 100, it represents that the ore deposit may be considered as impermeable and unleachable. These values bound the possible ranges in behavior of the system. Based on the double-porosity model, the relation between particle size and leachability is developed, and the effects of double porosities on the concentration of a dissolved mineral are investigated. It is demonstrated through model results that the recovery rate of a valuable mineral is mainly determined by the effective porosity of the fracture pore system, the porosity of the rock matrix system, and their ratios in addition to the concentration of reagent and the ore grade.","PeriodicalId":195550,"journal":{"name":"Mineral Resources Engineering","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131378188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SIMULATION OF A LARGE OPEN PIT MINE OPERATION IN AUSTRALIA","authors":"A. Basu","doi":"10.1142/S0950609899000189","DOIUrl":"https://doi.org/10.1142/S0950609899000189","url":null,"abstract":"The open pit gold mining operation by Kalgoorlie Consolidated Gold Mines Pty Ltd (KCGM) is the largest in Australia. The final pit will result in combining a few existing pits and underground operations. That is why the current operation is also known as the \"Super Pit\". The scale of the operation demands efficient planning and the company has a very strong strategic planning department to support the mine planning and design activities. The author was supported by the KCGM in undertaking a study of the production system for the open pit mine operation and to develop a computer simulation of the existing system. A graduate student started working on this project as his Master's Thesis (Sappington, 1997) under the supervision of the author. This paper presents the initial study, formulation, and coding of the simulation and animation model developed for the above-mentioned operation. The model developed was also validated against existing performance measures and produced satisfactory results. Advantage of having such a model are emphasised and its role in strategic planning are addressed. The model developed was used later to test a few dispatch algorithm and for proposing a dispatch algorithm. However, the detailed sensitivity analysis and discussion of the dispatch algorithm are beyond the current scope of this paper.","PeriodicalId":195550,"journal":{"name":"Mineral Resources Engineering","volume":"08 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129275676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MAINTENANCE AND COST EVALUATION OF AN AUTOMATED HAULAGE TRUCK AT INCO LIMITED","authors":"Mark Ashcroft, N. Vagenas, G. Baiden","doi":"10.1142/S0950609899000207","DOIUrl":"https://doi.org/10.1142/S0950609899000207","url":null,"abstract":"In 1983, Inco Limited began a program to design a rapid ore transportation system. This program was designed to serve two purposes: to provide a new effective material transport system for ramp haulage and to perform research and development to develop enabling technologies for future mine automation. As a result of the program, Inco designed and constructed a prototype automatic haulage truck. The premise of the truck operation was to serve as a haulage system on mining horizons where conveyor belt systems were not feasible. The intention was for the truck to haul material from a loading chute to a dumping area, using a self-guiding mechanism. The truck was commissioned to operate at Inco's Little Stobie Mine in May 1991. This paper discusses the maintenance characteristics of the automated haulage truck at Little Stobie mine of Inco Limited in Ontario, Canada. The paper also discusses the truck's performance compared to conventional truck haulage systems of similar capacity. The maintenance study of the 70-ton trolley-driven automatic truck presented in this paper covers the period of May 1991 to December 1993. The study discusses failure characteristics, frequency of occurrence of faults and calculation of the truck's availability. Furthermore, indexed cost information related to the truck's productivity is also presented. The outcome of this paper will indicate that automation of truck haulage systems is a reliable and cost-effective alternative for underground mines.","PeriodicalId":195550,"journal":{"name":"Mineral Resources Engineering","volume":"220 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114746420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"OVERVIEW OF SELECTED MINING LAW ISSUES IN VENEZUELA","authors":"Roberto Mendoza","doi":"10.1142/S0950609899000104","DOIUrl":"https://doi.org/10.1142/S0950609899000104","url":null,"abstract":"","PeriodicalId":195550,"journal":{"name":"Mineral Resources Engineering","volume":"214 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123570771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"RUSSIA PLODS ON WITH PRODUCTION SHARING CONCEPT","authors":"S. Horton, Mikhail Y. Galyatin","doi":"10.1142/S0950609899000116","DOIUrl":"https://doi.org/10.1142/S0950609899000116","url":null,"abstract":"","PeriodicalId":195550,"journal":{"name":"Mineral Resources Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124861977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"THE NEW BOLIVIAN MINING CODE","authors":"Teddy Cuentas Bascope","doi":"10.1142/S0950609899000050","DOIUrl":"https://doi.org/10.1142/S0950609899000050","url":null,"abstract":"As of 1952, and well into the 80's, the Bolivian mining industry's main characteristic was its ownership, the State; which played a protectionist and leading role in pro duction. Under this model, all regulations related to mining property were focused to guarantee a fast, easy access by Corporaci Un Minera de Bolivia, COMIBOL (Bolivian Mining State Corporation) to the lands mineral resources, thus giving the Corporation a limitless operational frame, and allowing it to perform its main objective as the main source of mining production. Juridical security of private mining ownership, was indeed a secondary objective. Large mineralised areas of the Bolivian land, were assigned to COMIBOL by the State; all these land allo cations had a 5 km security border zone (approximately 8.06 miles) within which, private rights to ownership were banned. Juridical regulations on Fiscal reserves were created parallel to the Mining Code which was current at the time, and which covered more than 70% of the total mineralized areas of the country, thus, private access to such territories were only available through concessional rights through concession-contract and leasing agreements — for limited periods of time. Un der such conditions, Bolivia marched into the 1980s with a negative growth rate, based on low investments — especially, in exploration — a growing technological delay, intensive use of labor, insufficient management capacity, a limited access to finance, and in general, very low; which was covered at that time by high mineral and metal prices in the international market. The fall of metal and mineral prices in the International Market, which took place at the end of 1985, triggered the fall of the State protectionist model, and the virtual bankruptcy of the Bolivian Mining Corporation which came to an accumulated deficit of about 700 million dollars (1980-1985), not withstanding the losses of the state smelting plant which had reached over 300 million during the same period. Mining exports started to be severely undermined with its logical negative impact on tax revenues, which in turn undermined the economies of the metal and mineral producing areas; this led to the consequent loss of legitimacy of Mining vis-vis the civil population. Facing exhaustion and unfeasibility, the States protectionist model, had to be reformed. The need of a profound structural reform in the Bolivian mining sector required the","PeriodicalId":195550,"journal":{"name":"Mineral Resources Engineering","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114703145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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