One of the most important problems facing the gold industry is that the placer and free milling gold ores are almost terminating. Hence, the use of refractory ores has been increased during the recent years. In genera...One of the most important problems facing the gold industry is that the placer and free milling gold ores are almost terminating. Hence, the use of refractory ores has been increased during the recent years. In general, gold refractory ores occurs in various types of deposits associated with a range of minerals. Among the refractory ores, the sulfide type is the most common. The methodology employed in the mining process depends on the mode of occurrence of the ore and on the particle size, shape and degree of purity of the auriferous species. We have undertaken a mineralogical investigation of a representative sample of a complex gold mining ore collected in the municipality of Princesa Isabel, Paraiba, Brazil, using X-ray fluorescence spectrometry, X-ray diffractometry, infrared spectroscopy, inductively coupled plasma-atomic emission spectrometry and the Fire Assay. The results showed that the arsenic content of the ore was closely related to the gold content, and that the occurrence of “invisible gold” was associated primarily with pyrite and secondarily with arsenopyrite. The sulfur content of the ore was directly related to its refractoriness. It is concluded that gold mineralization in the study area is mainly of the gold-quartz-sulfide veins (lode gold), while the gold found in the mini-fractures of the deposits is probably associated with the hydrothermal processes that occurred in the region.展开更多
The lack of care related to maintenance management is directly linked to the absence of plans for maintenance of buildings. Because of that, there is a big incidence of building accidents caused by the negligence of m...The lack of care related to maintenance management is directly linked to the absence of plans for maintenance of buildings. Because of that, there is a big incidence of building accidents caused by the negligence of managers and the lack of investment. The research has shown that, although building inspection is a consolidated building maintenance tool, managers do not prepare their building maintenance plan, nor use building inspection as a tool, leading the buildings to the premature obsolescence. The research calls attention to the building inspection technique that can be used to evaluate building maintenance and conservation. It is also a tool for analysis and investment planning based on actions to solve failures and anomalies that might come out during the building inspection. Those failures and anomalies are classified according to their degree of risk, determining the technical priorities of the investment adjustment in the maintenance plan. The paper presents a risk analysis methodology which classifies inspect elements in a building, determining the priority order of services to be executed on a scale from minimum risk （1） to imminent risk （5）. The method shows a tool for building inspection, and it serves as a guideline for building maintenance interventions.展开更多
基金the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq,grant no.550261/2010-9)for financial support
文摘One of the most important problems facing the gold industry is that the placer and free milling gold ores are almost terminating. Hence, the use of refractory ores has been increased during the recent years. In general, gold refractory ores occurs in various types of deposits associated with a range of minerals. Among the refractory ores, the sulfide type is the most common. The methodology employed in the mining process depends on the mode of occurrence of the ore and on the particle size, shape and degree of purity of the auriferous species. We have undertaken a mineralogical investigation of a representative sample of a complex gold mining ore collected in the municipality of Princesa Isabel, Paraiba, Brazil, using X-ray fluorescence spectrometry, X-ray diffractometry, infrared spectroscopy, inductively coupled plasma-atomic emission spectrometry and the Fire Assay. The results showed that the arsenic content of the ore was closely related to the gold content, and that the occurrence of “invisible gold” was associated primarily with pyrite and secondarily with arsenopyrite. The sulfur content of the ore was directly related to its refractoriness. It is concluded that gold mineralization in the study area is mainly of the gold-quartz-sulfide veins (lode gold), while the gold found in the mini-fractures of the deposits is probably associated with the hydrothermal processes that occurred in the region.
文摘The lack of care related to maintenance management is directly linked to the absence of plans for maintenance of buildings. Because of that, there is a big incidence of building accidents caused by the negligence of managers and the lack of investment. The research has shown that, although building inspection is a consolidated building maintenance tool, managers do not prepare their building maintenance plan, nor use building inspection as a tool, leading the buildings to the premature obsolescence. The research calls attention to the building inspection technique that can be used to evaluate building maintenance and conservation. It is also a tool for analysis and investment planning based on actions to solve failures and anomalies that might come out during the building inspection. Those failures and anomalies are classified according to their degree of risk, determining the technical priorities of the investment adjustment in the maintenance plan. The paper presents a risk analysis methodology which classifies inspect elements in a building, determining the priority order of services to be executed on a scale from minimum risk （1） to imminent risk （5）. The method shows a tool for building inspection, and it serves as a guideline for building maintenance interventions.
