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991.
992.
全逆流混合澄清器在溶剂萃取厂中的应用 总被引:2,自引:0,他引:2
本文综述了全逆流混合澄清器的结构特征、主要优点和在稀土分离、铀、钨及废水处理等领域的12个工厂应用的结果;并与普通混合澄清器进行了萃取级效率、溶剂夹带损失和经济效益对比。 相似文献
993.
介绍了闭路湿磨分级工艺中采用斜窄流分级斗 ,运用浅层沉降原理及斜窄流道的边壁剪切效应 ,缩短沉降距离以提高单位占地面积产能和改善矿浆的分散作用和分级效率 ,运用窄小的溢出面积使细粒及时溢出以提高分离精度和分级质效率的研究成果。该机已在某选厂生产使用中 ,用于闭路磨矿按 43 μm粒度分级 ,单位占地面积产能 7.5 1m3 / (m2 ·h)或 2 .91t/ (m2 ·h) ,分级质效率 5 9.89% ,底流浓度 5 8.8% ,溢流浓度 18.7% ,成功替代12 5mm水力旋流器。 相似文献
994.
矿山关闭及其生态环境恢复分析 总被引:13,自引:0,他引:13
矿山关闭及其生态环境恢复已成为我国的研究重点和难点,但其关闭的科学程序与相应措施还未得到深入研究。本文从矿山可持续发展角度,针对矿山关闭中存在的问题,本文根据国内外相关文献和我国矿山关闭现状情况.阐明矿山关闭及其生态环境恢复中存在矿企外部成本转嫁、产权配置效率低、缺少闭矿规划和忽视生态安全等的问题.在闭矿后合理发展生态农业是缓解经济衰竭的重要措施.并提出编制闭矿规划、调整产权关系、生态环境乡土化、加强矿区地质环境与生态环境的监测、发展特色旅游事业等相应建议。 相似文献
995.
996.
Hao Wang Shiteng Wang Yujie Wang Yuhang Fu Yi Cheng 《American Institute of Chemical Engineers》2022,68(3):e17519
A ternary fluid color-gradient lattice Boltzmann model is proposed to investigate the effect of mixing-induced dynamic interfacial tension on the diffusive mixing of two fluids inside microdroplets moving in a third continuous phase through a baffled channel. The diffusion coefficient of binary mixtures and dynamic interfacial tension in this model can be directly defined and independently adjusted. The simulation results show that the dynamic interfacial tension between miscible binary fluids at interfaces with ambient phase would lead to the motion of the interface and redistribution of solutes inside the droplet during mixing. The larger initial interfacial tension gradient would improve mixing efficiency at early stages by promoting faster solute flow. The present model can be easily applied to quantitatively characterize the mixing behavior inside droplets in the practical processes involving the dynamic interfacial tension phenomenon and inspire new designs for mixing intensification. 相似文献
997.
为研究工业副产石膏在水泥中的缓凝机理及效果,探索工业副产石膏规模化应用于水泥生产的可行性,我公司利用钛石膏、磷石膏、硫石膏等工业副产石膏进行了用作水泥缓凝材料的工业试验,并提出了资源化利用的方案。实验结果表明单独使用钛石膏按1.3%比例掺入32.5级水泥中会增加水泥的28 d强度,单掺磷石膏会对42.5级水泥的强度有不利影响。 相似文献
998.
Beiyue Ma Xinming Ren Zhi Gao Jialong Tian Zhouhua Jiang Wenyu Zan Jingkun Yu Fan Qian Yingnan Cao Gaofeng Fu 《International Journal of Applied Ceramic Technology》2022,19(3):1265-1273
Composite additives are an efficient means to improve the high-temperature stability and slag resistance of low-carbon MgO-C refractories. In this work, Al2O3-SiC powder was firstly synthesized from electroceramics waste by carbon embedded method at 1500°C, 1550°C, and 1600°C for 4 h, and then the as-synthesized Al2O3-SiC powder was used as an additive to low-carbon MgO-C refractories. The effects of its addition amounts of 0, 2.5 wt.%, 5.0 wt.%, and 7.5 wt.% on the properties of the refractories were investigated in detail. It was found that increasing the heat treatment temperature is beneficial to the phase conversion of mullite and quartz to alumina and silicon carbide in the electroceramics waste. Furthermore, the addition of Al2O3-SiC powder effectively improves the performance of low-carbon MgO-C samples, and the formation of spinel dense layer and high-viscosity isolation layer is the internal reason for the improvement of the oxidation resistance and slag resistance of low-carbon MgO-C samples. This work provides ideas for the reuse of electroceramics waste and presents an alternative strategy for the performance optimization of low-carbon MgO-C refractories. 相似文献
999.
Xiaolong Fu Deyou Li Hongjie Wang Guanghui Zhang Zhenggui Li Xianzhu Wei 《Journal of Mechanical Science and Technology》2018,32(5):2069-2078
The transient flow in pump-turbines during the load rejection process is very complex. However, few studies have been conducted on three-dimensional (3-D) numerical simulation. Hence, we simulated 3-D transient turbulent flow in a pump-turbine during the load rejection process using the calculation method of coupling the flow with the rotor motion of rigid body. To simulate the unsteady boundary conditions, the dynamic closing process of the guide vanes was simulated with the dynamic mesh technology. The boundary conditions at the spiral-casing inlet and the draft tube outlet were determined using the user defined functions (UDF) according to the experimental data. The numerical results of the rotational speeds show a good agreement with the experimental data. Then, the complex transient flow in the pump-turbine during the load rejection process was analyzed based on the numerical results. The results show that there are severe unsteady vortex flows in the vaneless space near the conditions under which the hydraulic torque on the runner equals to zero. When the pump-turbine operates into the maximum reverse discharge condition in the reverse pump operating process, the unsteady vortex flows in the vaneless space are instantaneously impacted into the region between the guide vanes and the stay vanes by the sudden reverse flows. The formation and development mechanism of the unsteady vortex flow in the vaneless space is associated with the distribution characteristic of the velocity field. 相似文献
1000.
Geometric error compensation for five-axis ball-end milling by considering machined surface textures
Guoqiang Fu Tengda Gu Hongli Gao Yu’an Jin Xiaolei Deng 《The International Journal of Advanced Manufacturing Technology》2018,99(5-8):1235-1248
Arbitrarily adjusting tool poses during error compensation may affect the quality of surface textures. This paper presents one tool center limitation-based geometric error compensation for five-axis ball-end milling to avoid the unexpected machined textures. Firstly, the mechanism of cutter location generation with cuter contact (CC) trajectory is analyzed. Due to zero bottom radius of ball-end cutter, CC points of the surface are only related to the tool center of the cutter. Realizing that, tool center limitation method of ball-end milling is established based on the generation of movements of all axes in order to ensure the machined textures. Then, geometric error compensation of ball-end milling is expressed as optimizing rotation angles of rotary axes by limiting tool centers of cutter locations. Next, particle swarm optimization (PSO) is intergraded into the geometric error compensation to obtain the compensated numerical control (NC) code. The limited region for particles of rotation angles is established, and moving criterion with a mutation operation is presented. With the help of the tool center limitation method, fitnesses of all particles are calculated with the integrated geometric error model. In this way, surface textures are considered and geometric errors of the machine tool are reduced. At last, cutting experiments on five-axis ball-end milling are carried out to testify the effectiveness of the proposed geometric error compensation. 相似文献