IJAT Vol.16 No.6 pp. 756-765
doi: 10.20965/ijat.2022.p0756


Influence of Agitator Shape on Characteristics and Grinding Efficiency of Attritor Mill

Chenzuo Ye*1, Yutaro Takaya*2,*3, Yuki Tsunazawa*2,*4, Kazuhiro Mochidzuki*2,*5, and Chiharu Tokoro*2,*3,†

*1Graduate School of Creative Science and Engineering, Waseda University
3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan

*2Faculty of Science and Engineering, Waseda University, Tokyo, Japan

Corresponding author

*3Faculty of Engineering, The University of Tokyo, Tokyo, Japan

*4Geological Survey of Japan (GSJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan

*5Retoca Laboratory LLC, Funabashi, Japan

April 23, 2022
July 19, 2022
November 5, 2022
photovoltaic panel recycling, attritor mill, agitator shape, grinding kinetics, DEM simulation

Grinding is a unit of operation of a pure mechanical process. An attritor is a grinder able to be used for fine or selective grinding. However, few studies have reported on the optimum design for the attritor. The attritor’s grinding characteristics and grinding effect depend not only on the operating conditions, but also on the geometry of the agitator. Therefore, we investigated the effect of the agitator shape on the grinding efficiency from the viewpoint of experiments, kinetic analysis, and discrete element method (DEM) simulations. We conducted grinding experiments with two different agitators. One was Agitator A, a traditional design with two pairs of 90° staggered mixing arms at the middle and bottom of the mixing shaft. The other was Agitator B, with a lower mixing arm inclined by 10° along the horizontal direction. We found that the grinding rate constant of Agitator B was approximately 40% greater than that of Agitator A. Although the size distribution of the particles was relatively dispersed after grinding with Agitator B, the distribution was concentrated mainly within two ranges (<0.5 mm and 2–4 mm) with Agitator A. These results and an elemental analysis of each size fraction suggested that the dominating grinding mode in Agitator A was surface grinding, whereas in Agitator B, it was bulk grinding. In terms of the influence of the agitator shape, the DEM simulation results showed that the kinetic energy of the grinding media in Agitator B was 0.0046 J/s, i.e., larger than the 0.0035 J/s obtained for Agitator A. A collision energy analysis showed that the dominating collision was between the media and wall in the tangential direction for both models. The collision energy of the media in Agitator B was larger than that of that in Agitator A. The results from the DEM simulation can help us evaluate the experimental results and infer the reasons why the grinding rate constant in Agitator B is larger than that in Agitator A.

Cite this article as:
C. Ye, Y. Takaya, Y. Tsunazawa, K. Mochidzuki, and C. Tokoro, “Influence of Agitator Shape on Characteristics and Grinding Efficiency of Attritor Mill,” Int. J. Automation Technol., Vol.16 No.6, pp. 756-765, 2022.
Data files:
  1. [1] C. Tokoro, S. Lim, Y. Sawamura, M. Kondo, K. Mochidzuki, T. Koita, T. Namihira, and Y. Kikuchi, “Copper/Silver Recovery from Photovoltaic Panel Sheet by Electrical Dismantling Method,” Int. J. Automation Technol., Vol.14, No.6, pp. 966-974, 2020.
  2. [2] Y. Kishita and Y. Umeda, “Development of Japan’s photovoltaic deployment scenarios in 2030,” Int. J. Automation Technol., Vol.11, No.4, pp. 583-591, 2017.
  3. [3] M. Elrawemi, L. Blunt, H. Muhamedsalih, F. Gao, and L. Fleming, “Implementation of in process surface metrology for R2R flexible PV barrier films,” Int. J. Automation Technol., Vol.9, No.3, pp. 312-321, 2015.
  4. [4] M. M. Aman, K. H. Solangi, M. S. Hossain, A. Badarudin, G. B. Jasmon, H. Mokhlis, A. H. A. Bakar, and S. N. Kazi, “A review of Safety, Health and Environmental (SHE) issues of solar energy system,” Renewable and Sustainable Energy Reviews, Vol.41, pp. 1190-1204, 2015.
  5. [5] F. Corcelli, M. Ripa, E. Leccisi, V. Cigolotti, V. Fiandra, G. Graditi, L. Sannino, M. Tammaro, and S. Ulgiati, “Sustainable urban electricity supply chain – Indicators of material recovery and energy savings from crystalline silicon photovoltaic panels end-of-life,” Ecological Indicators, Vol.94, Part 3, pp. 37-51, 2018.
  6. [6] Y. Kikuchi, A. Heiho, Y. Dou, I. Suwa, I.-C. Chen, Y. Fukushima, and C. Tokoro, “Defining Requirements on Technology Systems Assessment from Life Cycle Perspectives: Cases on Recycling of Photovoltaic and Secondary Batteries,” Int. J. Automation Technol., Vol.14, No.6, pp. 890-908, 2020.
  7. [7] K. Fujimoto, S. Fukushige, and H. Kobayashi, “Data Assimilation Mechanism for Lifecycle Simulation Focusing on Process Behaviors,” Int. J. Automation Technol., Vol.14, No.6, pp. 882-889, 2020.
  8. [8] C. Tokoro, M. Nishi, and Y. Tsunazawa, “Selective grinding of glass to remove resin for silicon-based photovoltaic panel recycling,” Advanced Powder Technology, Vol.32, Issue 3, pp. 841-849, 2021.
  9. [9] Y. Tsunazawa, S. Hisatomi, S. Murakami, and C. Tokoro, “Investigation and evaluation of the detachment of printed circuit boards from waste appliances for effective recycling,” Waste Management, Vol.78, pp. 474-482, 2018.
  10. [10] Y. Tsunazawa et al., “Investigation of part detachment process from printed circuit boards for effective recycling using particle-based simulation,” Materials Trans., Vol.57, No.12, pp. 2146-2152, 2016.
  11. [11] S. Hasegawa, Y. Kinoshita, T. Yamada, M. Inoue, and S. Bracke, “Disassembly reuse part selection for recovery rate and cost with lifetime analysis,” Int. J. Automation Technol., Vol.12, No.6, pp. 822-832, 2018.
  12. [12] M. Matsumoto, N. Mishima, and S. Kondoh, “Tele-Inverse Manufacturing – An International E-Waste Recycling Proposal,” Int. J. Automation Technol., Vol.3, No.1, pp. 11-18, 2009.
  13. [13] A. Szegvari and M. Yang, “Attritor grinding and dispersing equipment,” Union Process Incorporated, pp. 311-345, 1999.
  14. [14] C. Tokoro, Y. Ishii, Y. Tsunazawa, X. Jiang, K. Okuyama, M. Iwamoto, and Y. Sekine, “Optimum design of agitator geometry for a dry stirred media mill by the discrete element method,” Advanced Powder Technology, Vol.32, Issue 3, pp. 850-859, 2021.
  15. [15] Y. Nagata, M. Minagawa, S. Hisatomi, Y. Tsunazawa, K. Okuyama, M. Iwamoto, Y. Sekine, and C. Tokoro, “Investigation of optimum design for nanoparticle dispersion in centrifugal bead mill using DEM-CFD simulation,” Advanced Powder Technology, Vol.30, Issue 5, pp. 1034-1042, 2019.
  16. [16] P. A. Cundall and O. D. L. Strack, “A discrete numerical model for granular assemblies,” Géotechnique, Vol.29, Issue 1, pp. 47-65, 1979.
  17. [17] Y. Tsunazawa, Y. Shigeto, C. Tokoro, and M. Sakai, “Numerical simulation of industrial die filling using the discrete element method,” Chemical Engineering Science, Vol.138, pp. 791-809, 2015.
  18. [18] B. M. Ghodki, K. C. Kumar, and T. K. Goswami, “Modeling breakage and motion of black pepper seeds in cryogenic mill,” Advanced Powder Technology, Vol.29, Issue 5, pp. 1055-1071, 2018.
  19. [19] Y. Tsunazawa, D. Fujihashi, S. Fukui, M. Sakai, and C. Tokoro, “Contact force model including the liquid-bridge force for wet-particle simulation using the discrete element method,” Advanced Powder Technology, Vol.27, Issue 2, pp. 652-660, 2016.
  20. [20] M. Yamamoto, S. Ishihara, and J. Kano, “Evaluation of particle density effect for mixing behavior in a rotating drum mixer by DEM simulation,” Advanced Powder Technology, Vol.27, Issue 3, pp. 864-870, 2016.
  21. [21] Y. Kosaku, Y. Tsunazawa, and C. Tokoro, “Investigating the upper limit for applying the coarse grain model in a discrete element method examining mixing processes in a rolling drum,” Advanced Powder Technology, Vol.32, Issue 11, pp. 3980-3989, 2021.
  22. [22] Y. Takaya, Y. Xiao, Y. Tsunazawa, M. Córdova, and C. Tokoro, “Mechanochemical degradation treatment of TBBPA: A kinetic approach for predicting the degradation rate constant,” Advanced Powder Technology, Vol.33, Issue 3, 103469, 2022.
  23. [23] Y. Nagata, Y. Tsunazawa, K. Tsukada, Y. Yaguchi, Y. Ebisu, K. Mitsuhashi, and C. Tokoro, “Effect of the roll stud diameter on the capacity of a high-pressure grinding roll using the discrete element method,” Minerals Engineering, Vol.154, 106412, 2020.
  24. [24] S. Fukui, Y. Tsunazawa, S. Hisatomi, G. Granata, C. Tokoro, K. Okuyama, M. Iwamoto, and Y. Sekine, “Effect of agitator shaft direction on grinding performance in media stirred mill: investigation using DEM simulation,” Materials Trans., Vol.59. Issue 3, pp. 488-493, 2018.
  25. [25] Y. Tsuji, T. Kawaguchi, and T. Tanaka, “Discrete particle simulation of two-dimensional fluidized bed,” Powder Technology, Vol.77, Issue 1, pp. 79-87, 1993.

*This site is desgined based on HTML5 and CSS3 for modern browsers, e.g. Chrome, Firefox, Safari, Edge, Opera.

Last updated on Jun. 03, 2024