Preferentially selective extraction of lithium from spent LiCoO_(2)cathodes by medium-temperature carbon reduction roasting

Lithium recovery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of lithium.The medium-temperature carbon reduction roasting was proposed to preferential selective extraction of lithium from spent Li-CoO_(2)(LCO)cathodes to overcome the incomplete recovery and loss of lithium during the recycling process.The LCO layered structure was destroyed and lithium was completely converted into water-soluble Li2CO_(3)under a suitable temperature to control the reduced state of the cobalt oxide.The Co metal agglomerates generated during medium-temperature carbon reduction roasting were broken by wet grinding and ultrasonic crushing to release the entrained lithium.The results showed that 99.10%of the whole lithium could be recovered as Li2CO_(3)with a purity of 99.55%.This work provided a new perspective on the preferentially selective extraction of lithium from spent lithium batteries.

温拌添加剂对沥青结合料PG分级的影响研究

采用室内试验量化分析了不同温拌添加剂对基质沥青和SBS改性沥青结合料PG分级的影响。结果表明：温拌添加剂对沥青结合料的PG分级影响程度取决于沥青和添加剂种类、添加剂含量和RTFOT老化温度等。石蜡基添加剂Sasobit对沥青结合料PG分级产生强化作用,在其典型掺量3%时,沥青结合料的PG分级上限、下限和中间温度可分别提高13.5、6.9和5.0℃。在正常掺量范围内,Aspha-min温拌添加剂对沥青结合料的PG分级上限、下限和中间温度影响不大。剔除个别异常数据,RTFOT老化温度163~133℃的变化对沥青结合料PG分级无显著影响。

Using nonparametric modeling approaches and remote sensing imagery to estimate ecological welfare forest biomass

The spatial distribution of forest biomass is closely related with carbon cycle, climate change, forest productivity, and biodiversity. Efficient quantification of biomass provides important information about forest quality and health. With the rising awareness of sustainable development, the ecological benefits of forest biomass attract more attention compared to traditional wood supply function. In this study, two nonparametric modeling approaches, random forest（RF） and support vector machine were adopted to estimate above ground biomass（AGB） using widely used Landsat imagery in the region,especially within the ecological forest of Fuyang District in Zhejiang Province, China. Correlation analysis was accomplished and model parameters were optimized during the modeling process. As a result, the best performance modeling method RF was implemented to produce an AGB estimation map. The predicted map of AGB in the study area showed obvious spatial variability and demonstrated that within the current ecological forest zone, as well as the protected areas, the average of AGB were higher than the ordinary forest. The quantification of AGB was proven to have a close relationship with the local forest policy and management pattern, which indicated that combining remote-sensing imagery and forest biophysical property would provide considerable guidance for making beneficial decisions.

Study on Comprehensive Evaluation of New Urbanization Level in Qinghai Province

The new type of urbanization has always been regarded as an important force to promote economic and social development and an important means to realize agricultural modernization.In order to analyze the problems existing in the process of urbanization in Qinghai Province,5 second-level indexes and 17 third-level indexes were constructed to establish a comprehensive evaluation index system of urbanization development level,and the entropy method was used to analyze the urbanization level of Qinghai Province from 1999 to 2018.The results show that the urbanization of Qinghai Province can be divided into three stages:in the first stage(from 1999 to 2005),the urbanization of Qinghai Province was basically in a stage of slow development;in the second stage(from 2006 to 2011),the urbanization of Qinghai Province was in the stage of slow growth;in the third stage(from 2012 to 2018),urbanization in Qinghai Province was in the stage of rapid and high-quality development.

Crystallization of battery-grade lithium carbonate with high recovery rate via solid-liquid reaction

Lithium carbonate(Li_(2)CO_(3))stands as a pivotal raw material within the lithium-ion battery industry.Hereby,we propose a solid-liquid reaction crystallization method,employing powdered sodium carbonate instead of its solution,which minimizes the water introduction and markedly elevates one-step lithium recovery rate.Through kinetic calculations,the Li_(2)CO_(3)solid-liquid reaction crystallization process conforms by the Avrami equation rather than shrinking core model,which means the dissolution rate of Na_(2)CO_(3)is the most important factor affecting the reaction process.The effects of reaction conditions such as temperature and stirring speed on the Li_(2)CO_(3)precipitation behavior were evaluated.The results indicated that temperature is a most essential parameter than other reaction conditions or stirring speed.The exceptional 93%recovery of Li_(2)CO_(3)at 90℃with a remarkable purity of 99.5%was achieved by using 1.2 M ratio of Na_(2)CO_(3)/Li_(2)SO_(4).This method provides a new idea for the efficient preparation of battery-grade Li_(2)CO_(3).

Eco-environmental vulnerability assessment for large drinking water resource： a case study of Qiandao Lake Area, China

The Qiandao Lake Area （QLA） is of great significance in terms of drinking water supply in East Coast China as well as a nationally renowned tourist attraction. A series of laws and regulations regarding the QLA environment have been enacted and implemented throughout the past decade with the aim of negating the harmful effects associated with expanding urbanization and industrialization. In this research, an assessment framework was developed to analyze the eco-environ- mental vulnerability of the QLA from 1990-2010 by integrating fuzzy analytic hierarchy process （FAHP） and geographical information systems （GIS） in an attempt to gain insights into the status quo of the QLA so as to review and evaluate the effectiveness of the related policies. After processing and analyzing the temporal and spatial variation of eco-environmental vulnerability and major environ- mental issues in the QLA, we found that the state of eco- environmental vulnerability of the QLA was acceptable, though a moderate deterioration was detected during the study period. Furthermore, analysis of the combination of vulnerability and water quality indicated that the water quality showed signs of declination, though the overall status remained satisfactory. It was hence concluded that the collective protection and treatment actions were effective over the study period, whereas immediately stricter measures would be required for protecting the drinking water quality from domestic sewage and industrial wastewater. Finally, the spatial variation of the eco-environmental vulnerability assessment also implied that specifically more targeted measures should be adoptedin respective regions for long-term sustainable develop- ment of the QLA.