通过化学分析、化学物相分析、光学显微镜鉴定,并结合扫描电镜分析、X-射线衍射分析等手段,对西藏某银铅多金属矿进行了系统的工艺矿物学研究。研究结果表明,矿石中银、铅、锌为有回收价值的元素,铜和金单独回收难度较大。银矿物主要为...通过化学分析、化学物相分析、光学显微镜鉴定,并结合扫描电镜分析、X-射线衍射分析等手段,对西藏某银铅多金属矿进行了系统的工艺矿物学研究。研究结果表明,矿石中银、铅、锌为有回收价值的元素,铜和金单独回收难度较大。银矿物主要为辉银矿,银黝铜矿;铅矿物主要为方铅矿、铅矾和铅铁矾;锌矿物主要为闪锌矿;铜矿物主要为黄铜矿、黝铜矿及铜蓝等。其它金属矿物主要为赤铁矿、褐铁矿和黄铁矿。脉石矿物主要为石榴子石、石英、绿泥石等。选择-0.074 mm 60%作为较佳磨矿细度可以保证载银矿物方铅矿的单体解离,而其它矿物充分解离则需进一步磨细。辉银矿粒度很细,单独选出银精矿的可能性较小,与载体矿物方铅矿、黝铜矿在浮选过程中将随载体矿物一起进入到相应的选矿产品中。该研究对于选别银铅锌铜多金属矿有一定的指导意义。展开更多
Global warming has led to significant vegetation changes especially in the past 20 years. Hulun Buir Grassland in Inner Mongolia, one of the world’s three prairies, is undergoing a process of prominent warming and dr...Global warming has led to significant vegetation changes especially in the past 20 years. Hulun Buir Grassland in Inner Mongolia, one of the world’s three prairies, is undergoing a process of prominent warming and drying. It is essential to investigate the effects of climatic change （temperature and precipitation） on vegetation dynamics for a better understanding of climatic change. NDVI （Normalized Difference Vegetation Index）, reflecting characteristics of plant growth, vegetation coverage and biomass, is used as an indicator to monitor vegetation changes. GIMMS NDVI from 1981 to 2006 and MODIS NDVI from 2000 to 2009 were adopted and integrated in this study to extract the time series characteristics of vegetation changes in Hulun Buir Grassland. The responses of vegetation coverage to climatic change on the yearly, seasonal and monthly scales were analyzed combined with temperature and precipitation data of seven meteorological sites. In the past 30 years, vegetation coverage was more correlated with climatic factors, and the correlations were dependent on the time scales. On an inter-annual scale, vegetation change was better correlated with precipitation, suggesting that rainfall was the main factor for driving vegetation changes. On a seasonal-interannual scale, correlations between vegetation coverage change and climatic factors showed that the sensitivity of vegetation growth to the aqueous and thermal condition changes was different in different seasons. The sensitivity of vegetation growth to temperature in summers was higher than in the other seasons, while its sensitivity to rainfall in both summers and autumns was higher, especially in summers. On a monthly-interannual scale, correlations between vegetation coverage change and climatic factors during growth seasons showed that the response of vegetation changes to temperature in both April and May was stronger. This indicates that the temperature effect occurs in the early stage of vegetation growth. Correlations between vegetation growth and precipitation of the month before the current month, were better from May to August, showing a hysteresis response of vegetation growth to rainfall. Grasses get green and begin to grow in April, and the impacts of temperature on grass growth are obvious. The increase of NDVI in April may be due to climatic warming that leads to an advanced growth season. In summary, relationships between monthly-interannual variations of vegetation coverage and climatic factors represent the temporal rhythm controls of temperature and precipitation on grass growth largely.展开更多
文摘通过化学分析、化学物相分析、光学显微镜鉴定,并结合扫描电镜分析、X-射线衍射分析等手段,对西藏某银铅多金属矿进行了系统的工艺矿物学研究。研究结果表明,矿石中银、铅、锌为有回收价值的元素,铜和金单独回收难度较大。银矿物主要为辉银矿,银黝铜矿;铅矿物主要为方铅矿、铅矾和铅铁矾;锌矿物主要为闪锌矿;铜矿物主要为黄铜矿、黝铜矿及铜蓝等。其它金属矿物主要为赤铁矿、褐铁矿和黄铁矿。脉石矿物主要为石榴子石、石英、绿泥石等。选择-0.074 mm 60%作为较佳磨矿细度可以保证载银矿物方铅矿的单体解离,而其它矿物充分解离则需进一步磨细。辉银矿粒度很细,单独选出银精矿的可能性较小,与载体矿物方铅矿、黝铜矿在浮选过程中将随载体矿物一起进入到相应的选矿产品中。该研究对于选别银铅锌铜多金属矿有一定的指导意义。
基金Open Project of Hulun Buir Grassland Ecosystem Observation and Research Station, No.2010-10Open Project of Ministry of Agriculture Key Laboratory of Resource Remote Sensing and Digital Agriculture, No.RDA0803+1 种基金 No.RDA0903Basic Research Project of the Ministry of Science and Technology, No.2007FY110300
文摘Global warming has led to significant vegetation changes especially in the past 20 years. Hulun Buir Grassland in Inner Mongolia, one of the world’s three prairies, is undergoing a process of prominent warming and drying. It is essential to investigate the effects of climatic change （temperature and precipitation） on vegetation dynamics for a better understanding of climatic change. NDVI （Normalized Difference Vegetation Index）, reflecting characteristics of plant growth, vegetation coverage and biomass, is used as an indicator to monitor vegetation changes. GIMMS NDVI from 1981 to 2006 and MODIS NDVI from 2000 to 2009 were adopted and integrated in this study to extract the time series characteristics of vegetation changes in Hulun Buir Grassland. The responses of vegetation coverage to climatic change on the yearly, seasonal and monthly scales were analyzed combined with temperature and precipitation data of seven meteorological sites. In the past 30 years, vegetation coverage was more correlated with climatic factors, and the correlations were dependent on the time scales. On an inter-annual scale, vegetation change was better correlated with precipitation, suggesting that rainfall was the main factor for driving vegetation changes. On a seasonal-interannual scale, correlations between vegetation coverage change and climatic factors showed that the sensitivity of vegetation growth to the aqueous and thermal condition changes was different in different seasons. The sensitivity of vegetation growth to temperature in summers was higher than in the other seasons, while its sensitivity to rainfall in both summers and autumns was higher, especially in summers. On a monthly-interannual scale, correlations between vegetation coverage change and climatic factors during growth seasons showed that the response of vegetation changes to temperature in both April and May was stronger. This indicates that the temperature effect occurs in the early stage of vegetation growth. Correlations between vegetation growth and precipitation of the month before the current month, were better from May to August, showing a hysteresis response of vegetation growth to rainfall. Grasses get green and begin to grow in April, and the impacts of temperature on grass growth are obvious. The increase of NDVI in April may be due to climatic warming that leads to an advanced growth season. In summary, relationships between monthly-interannual variations of vegetation coverage and climatic factors represent the temporal rhythm controls of temperature and precipitation on grass growth largely.
