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排序方式: 共有9441条查询结果,搜索用时 31 毫秒
1.
《Advanced Powder Technology》2022,33(3):103450
In the present investigation, systematic grinding experiments were conducted in a laboratory ball mill to determine the breakage properties of low-grade PGE bearing chromite ore. The population balance modeling technique was used to study the breakage parameters such as primary breakage distribution (Bi, j) and the specific rates of breakage (Si). The breakage and selection function values were determined for six feed sizes. The results stated that the breakage follows the first-order grinding kinetics for all the feed sizes. It was observed that the coarser feed sizes exhibit higher selection function values than the finer feed size. Further, an artificial neural network was used to predict breakage characteristics of low-grade PGE bearing chromite ore. The predicted results obtained from the neural network modeling were close to the experimental results with a correlation of determination R2 = 0.99 for both product size and selection function. 相似文献
2.
分析了溢流型球磨机进料口矿浆泄漏的原因以及泄漏后给球磨机润滑系统和环境所带来的危害。通过对溢流型球磨机进料口密封装置的改进,减少和杜绝了矿浆泄漏,改善了球磨机运行环境,延长了润滑油使用周期、提高了球磨机有效作业率,降低了球磨机运行成本。 相似文献
3.
Harshita Gogoi V. Nirosha Anjali Jayakumar Keerthana Prabhu Meghna Maitra 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2018,40(1):39-44
In the present study, pre-treated paper mill sludge (PMS) was evaluated extensively as a substrate for production of acetone-butanol-ethanol using Clostridium sporogenes NCIM 2337. The PMS was subjected to three types of pre-treatment methods namely alkali, mechanical, and thermal treatment and was analyzed by SEM. The pre-treatment of PMS by alkali was observed to be more effective over the other pre-treatment methods. The alkali pre-treated sludge was then made to undergo fermentation, which showed the conventional process of acidogenesis followed by solventogenesis. The acetone, butanol, and ethanol concentration for 15% alkali pre-treated PMS was estimated to be maximum. 相似文献
4.
为了验证在某复杂难选铁矿石的选矿工艺中,应用高压辊磨机和立式搅拌磨的优越性,进行了一系列对比试验。结果表明,与颚式破碎机相比,高压辊磨机产品的粉矿率更高,产品的可磨性更好;与球磨机相比,立式搅拌磨机细磨效率更高、效果更好,相同磨矿细度下,立式搅拌磨机磨矿产品的解离度更高,磁选铁精矿品位也更高;高压辊磨+立式搅拌磨在处理复杂难选铁矿石方面具有显著的优势。 相似文献
5.
针对轧机垂直系统动力学参数可信度不足等问题,提出一种基于实测数据的改进粒子群算法辨识轧机垂直系统动力学参数的方法。首先,将轧机垂直系统刚度和阻尼考虑成达芬振子和范德波尔振子,构建轧机垂直系统非线性动力学模型,并对粒子群算法进行改进;然后,通过数值仿真算例辨识得到系统在感染噪声和不含噪声时的动力学参数,验证了该算法的有效性;最后,以现场某轧机垂直系统为研究对象,基于现场实测数据,应用该算法进行辨识,得到了轧机垂直系统动力学参数估计,通过实测位移、速度和加速度信号分别与辨识后的位移、速度和加速度信号进行对比,证明该方法辨识轧机垂直系统动力学参数结果可靠,具有一定的工程应用价值。 相似文献
6.
7.
《Ceramics International》2021,47(23):33405-33412
In this study, SnO2@MnO2@graphite (SMG) anode material is prepared via a facile ball-milling approach combined with hydrothermal treatment. SnO2 and MnO2 nanoparticles are evenly dispersed on numerous sheet-like graphite. MnO2 can not only play a catalytic role for facilitating the conversion reaction of Sn/Li2O to SnO2, but also as a barrier to impede the coarsening of Sn in the composite. Meanwhile, graphite nanosheets could serve as an ideal volume expansion buffer and good electron conductor. Consequently, the SMG anode delivers superior reversible capacity of 1048.5 mAhg−1, ideal rate capability of 522.2 mAhg−1 at 5.0 A g-1 and stable long-life cyclic performance of 814.8 mAhg−1 at 1.0 A g-1 after 1000 cycles. This result indicates that the incorporation of MnO2, graphite nanosheet and SnO2 have a great potential in enhancing the performance of SnO2-based anode for battery applications. 相似文献
8.
《Ceramics International》2021,47(23):32610-32618
AA7075 + 6%B4C+3%ZrC nano hybrid composite was successfully fabricated, with nano reinforcements composition in AA7075 alloy selected based on previous investigation, to achieve better mechanical performance. Two different sintering techniques, namely conventional and microwave, were implemented to determine the effect on microstructural and mechanical properties. Microstructural investigation was performed with the help of W-SEM. Tensile, compression, and hardness were measured with the help of UTM and Vickers microhardness machine. Porosity was calculated by using Archimedes principle. It was observed that the added nano ZrC particles formed agglomerates and the B4C particles were distributed homogenously. Composites processed by microwave sintering showed excellent mechanical properties compared to the conventionally sintered composites. No intermetallic compounds were detected in microwave sintered composites through XRD analysis, indicating strong and clean interface bonds between matrix and reinforcement particles. High strain to fracture value of 12.24% was noted in microwave sintered nano hybrid composite, while it was 6.12% for conventional sintered one. Fractography revealed no peeling action of reinforcements from the matrix material, and the mode of failure was brittle. It was concluded that, while fabricating nano range hybrid composites, the implementation of advanced sintering technique (microwave sintering) with low sintering temperatures and low sintering times with internal heat generations, helps in eliminating defects that may develop because of high surface energies of nano range reinforcements. 相似文献
9.
《International Journal of Hydrogen Energy》2021,46(60):30976-30987
Palm oil mill effluent (POME) is a wastewater effluent that is generated from palm oil milling. Treatment of POME, especially using biological treatment methods, is a challenge as it contains high amounts of organic and sulfur compounds, and it is highly acidic. In this research, the effects of zero-valent iron (ZVI) on the enhancement of methane production from POME via anaerobic digestion were investigated. Furthermore, to identify the reactor operation modes that were suitable for the addition of ZVI, anaerobic digestion of POME was tested in three reaction configurations: batch reactor, fed-batch reactor, and continuous stirred-tank reactor (CSTR). In the batch mode, where acidic POME was fed with 16 g/L of ZVI dose just once, methane production increased by 74%. However, as the oxidation of ZVI under anaerobic conditions led to the production of hydroxyl ions, the pH of the medium continuously increased from approximately 7 to 9, which is not suitable for methanogenesis. In the fed-batch mode that involved intermittent feeding of acidic POME, the pH of the culture media was maintained at 6.8. This is because the extra hydroxyl ions generated from the oxidation reaction of ZVI tended to neutralize the acids in the feeding substrate. In addition, ZVI promoted the production of methane from POME and increased the average methane content in biogas from 62% to 76%. In the CSTR mode, which involved continuous feeding of acidic POME, ZVI increased methane production by 86% (from 1.79 to 3.32 L/day), methane content in biogas from 60 to 75%, and total chemical oxygen demand (tCOD) removal efficiency from 78 to 89 to 88–95%. Thus, the addition of ZVI can be a potential strategy for in-situ methane enrichment of biogas by anaerobic digestion of POME. This is because ZVI acts as a buffer for acid generation and provides extra electrons, ferrous ions, and ferric ions, which promote key microbial activities in the anaerobic digestion process. 相似文献
10.
Jiri Cermak Lubomir Kral Pavla Roupcova 《International Journal of Hydrogen Energy》2021,46(27):14494-14507
Effect of chemical composition of Mg-xCu based alloys (x = 9.94–58.00 wt %) modified by KCl upon their hydrogen storage performance was studied. Kinetic curves and pressure-concentration isotherms were measured in the ranges up to 60 bar and 388 °C, respectively. It was observed that desorption rate dc/dt is not significantly influenced by the composition. Unknown Cu-rich phase was detected that has shown a catalytic effect on desorption from a mixture with other phases. Activation energy of hydrogen desorption decreased with increasing x from 180 kJ/mol down to 98 kJ/mol. Average hydride dissociation enthalpy, ΔH, for the lowest plateau was 75 kJ/mol which is equal to literature value for pure Mg. Slightly lover average value, 67 kJ/mol was obtained for the second plateau and ΔH for the third one decreased from 70 kJ/mol for the lowest to 49 kJ/mol for the highest x. 相似文献