Copper recovery and reduction of environmental loading from mine tailings by high‐pressure leaching and sx‐ew process

The flotation tailings obtained from Bor Copper Mine contain pyrite (FeS2) and chalcopyrite (CuFeS2), these sulfide minerals are known to promote acid mine drainage (AMD) which poses a serious threat to the environment and human health. This study focuses on the treatment of mine tailings to convert the AMD supporting minerals to more stable forms, while simultaneously valorizing the mine tailings. A combination of hydrometallurgical processes of high-pressure oxidative leaching (HPOL), solvent extraction (SX), and electrowinning (EW) were utilized to recover copper from mine tailings which contain about 0.3% Cu content. The HPOL process yielded a high copper leaching rate of 94.4% when water was used as a leaching medium. The copper leaching kinetics were promoted by the generation of sulfuric acid due to pyrite oxidation. It was also confirmed that a low iron concentration (1.4 g/L) and a high copper concentration (44.8 g/L) obtained in the stripped solution resulted in an improved copper electrodeposition current efficiency during copper electrowinning.Moreover, pyrite, which is primarily in the mine tailings, was converted into hematite after HPOL. A stability evaluation of the solid residue confirmed almost no elution of metal ions, confirming the reduced environmental loading of mine tailings through re-processing

Geochemical Characteristics of Tungsten in Miyako Granitoid and Scheelite-bearing Aplitic Veins at the Yamaguchi Cu-W Skarn Deposit, Iwate, Japan

Tungsten analyses were made on 16 samples collected from the North Miyako granitic body in Northeast Japan. Petrographic facies of the North granitic body vary from quartz diorite in the marginal zone (zone A), to tonalite and granodiorite (zone B), and to granite in the central zone (zone C). A large number of barren and scheelite-bearing aplitic veins are distributed around the Yamaguchi deposit which occurs in the contact aureole of zone C granite. The tungsten content of zone C granite is lower than that of the granitic rocks in zones A, B and the aplitic veins. It appears that tungsten in the differentiated granitic magma, which was associated with ore mineralization, was transported out of the magma chamber by magmatic fluids. The tungsten content is generally low in the North Miyako granitic rocks but high in granitic rocks of Okinoshima zoned pluton, as well as in Otani granite and Busetsu granite from the Southwest Japan. In the case of magnetite-series, however, the behavior of tungsten in the Miyako granitic body from the tungsten metallogenic province is similar to that of the Okinoshima zoned pluton from molybdenum metallogenic province in Southwest Japan. Behavior of tungsten in granitic magma is affected by magmatic evolution during the process of saturation of granitic melt with magmatic fluid.International Symposium on "Dawn of a New Natural History - Integration of Geoscience and Biodiversity Studies". 5-6 March 2004. Sapporo, Japan

Investigation of Trace Element Distribution in Permanent Root Dentine by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

In this study, we report on the effectiveness of using laser ablationinductively coupled plasma mass spectrometry (LA-ICP-MS) to analyze the compositionof trace elements within root dentinal tissue in permanent teeth. The trace elementdistribution in different dentine regions and age related changes in their concentrationwere investigated using the LA-ICP-MS technique, provided semi-quantitative data for12 trace elements among which Mg, Zn, and Sr ranked as the most abundant. Theresults demonstrated that most of the observed elements display conformity throughoutroot dentinal tissue, except for the higher concentrations of Mg in the cervical area andthe higher levels of Zn measured in the pulpal layer. Alterations in the levels of dentinalSr, Cr, Mn, and Se were also observed in relation to the age of dentinal tissue. Thefindings of this investigation indicate that the combination of EPMA and LA-ICP-MSmeasurements may prove instrumental to the further research of this topic in the future

Geology and geochemical characteristics of the Xiajinbao gold deposit in the Hebei Province, China

The Xiajinbao gold deposit is located in the Yanshan District of the North China Craton. The geology of the Xiajinbao deposit consists of Archean gneiss, Proterozoic sedimentary rocks, granite porphyry, quartz porphyry dikes, and diorite dikes. The diorite contains a large quantity of magnetite. The granite porphyry and quartz porphyry dikes, which contain trace amounts of ilmenite without magnetite, have high aluminum saturation index values and a low magnetic susceptibility. These rocks are classified as ilmenite series granitic rocks. The pyrite quartz veins (Stage I), pyrite-chalcopyrite quartz veins (Stage II), and sphalerite-galena quartz veins (Stage III) of the Xiajinbao deposit were hosted in the granite porphyry. Major gold mineralization was associated with the sphalerite-galena quartz veins. The homogenization temperature and salinity of the sphalerite-galena quartz veins are 220 degrees C in a mode and 9.1-13.8 wt%, respectively. The sulfur fugacity of the Xiajinbao deposit ranged 10(-7.8) -10(-11) and 10(-9.5) -10(-14.3) atm for the pyrite-chalcopyrite quartz veins and sphalerite-galena quartz veins, respectively. The formation environment of the sphalerite-galena quartz veins of the Xiajinbao deposit is similar to that of zoned base metal veins associated with oxidized magma. The oxygen and hydrogen isotope ratios of the hydrothermal solution in equilibrium with quartz from the sphalerite-galena quartz veins range from + 3.3 to + 5.5 and -38 to -41%, respectively, suggesting magmatic water. The range of sulfur isotope ratios of pyrite and galena from the sphalerite-galena quartz veins is from -0.2 to + 3.6%. These sulfur isotope ratios are in the range of ratios for ores formed by igneous activity associated with oxidized magma. Therefore, the gold mineralization of the Xiajinbao deposit is inferred to be the result of igneous activities from oxidized magmas, such as the diorite dikes, with the granite porphyry forming the host rock of the sphalerite-galena quartz veins of the Xiajinbao deposit

Investigation of Trace Element Distribution in Permanent Root Dentine by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

In this study, we report on the effectiveness of using laser ablationinductively coupled plasma mass spectrometry (LA-ICP-MS) to analyze the compositionof trace elements within root dentinal tissue in permanent teeth. The trace elementdistribution in different dentine regions and age related changes in their concentrationwere investigated using the LA-ICP-MS technique, provided semi-quantitative data for12 trace elements among which Mg, Zn, and Sr ranked as the most abundant. Theresults demonstrated that most of the observed elements display conformity throughoutroot dentinal tissue, except for the higher concentrations of Mg in the cervical area andthe higher levels of Zn measured in the pulpal layer. Alterations in the levels of dentinalSr, Cr, Mn, and Se were also observed in relation to the age of dentinal tissue. Thefindings of this investigation indicate that the combination of EPMA and LA-ICP-MSmeasurements may prove instrumental to the further research of this topic in the future