36

Team of Fluidization Technology

37

Brief Introduction

China has large reserves of low grade ores, which are difficult to be beneficiated by conventional processes. While these low grade ores are normally been treated as non-usable minerals in most countries, China has to utilize these low grade minerals to ensure the supply security one the one hand to support the social and economic development of China on the other hand. It is therefore crucial for China to find ways to utilize these low grade minerals.The main focuses of Team of Fluidization Technology is to realize the utilization of low grade iron ores through chemical reaction to transfer from non-beneficiated phases to easily processable phases. The mission of the team is to develop technologies to meet the great demands of low grade of mineral processing of China

Research Activities

Multiscale approaches will be adopted to solve the low grade mineral processing problems, e.g. phase and microstructure manipulation at the microscale, process intensification at the particle scale, scaleup principle at the reactor scale and key technologies development and system integration at the factory scale. It is our believe that only a comprehensive understanding from microscale to system scale could be acquired, may the new technologies be developed. The research activities in Team of Fluidization Technology includes:

Phase and microstructure tuning for low grade mineralsConversion kinetics and process intensificationModelling and simulation for reactor scaleupPowder product engineering (granulation, coating, surface modification, etc.)Key technologies development and pilot demonstration

Infrastructure

The team has over 50 members, including 1 member of Chinese Academy of Sciences, 4 professors, 5 associate professors, 7 assistant professors, 6 engineers, 4 administrative staffs, and 28 graduate students.The team has a variety of experimental equipment, like several batch scale fluidized bed reactors (Fig.1 left) and 2 continuous fluidized bed reactors with the capacity of 1-5kg/h (Fig. 1 right). The team also has established 1000t/a pilot scale fluidized bed facilities in Langfang campus of IPE, as shown in Fig. 2.

Team of Fluidization Technology

Fig.1 Lab scale fluidized bed reactors (batch scale facilities left and one of continuous fluidized bed right)

Fig.2 1000t/a pilot scale fluidized bed system for the direct reduction of iron ore

1. 2. 3.4.5.

38

Research Progress

1. New technology for upgrading Panxi ilmenite to synthetic rutile

The titanium resource reserve of Panxi area of China accounts over 36% of world total and 90% of China’s total. However, the titanium resource of Panxi area is difficult to be utilized due to low grade and high contents of MgO and CaO. From 1970s, Chinese government has pushed to develop utilization method for the Panxi ilmenite, where 4 pilot plants of 1000 t/a have been successively established, with joint efforts from all over China, over the past several decades, but these efforts all failed due to the problem of pulverization of the products.The team proposed to solve the problem by manipulating the phase and structure of ilmenite via fluidized bed roasting of

Fig.3. Microstructure evolution during the oxidation and reduction of Panxi ilmenite

Fig. 4. 10kt/a pilot plant for Panxi ilmenite to synthetic rutile

ilmenite powders. The phase and microstructure evolution during the oxidation and reduction process have been systematically investigated, as shown in Fig. 3. It was discovered that three dimensional (3D) rutile network formed during the oxidation of ilmenite could prevent the pulverization of ilmenite during leaching. However, the 3D rutile structure reduces significantly the rate of leaching. It was luckily discovered that through proper control of the reduction process, particles with 3D rutile network combined with reduction-induced micropores could be obtained. A new process that can speed up the rate of leaching while in the meantime to solve the long-standing pulverization problem was successfully developed for the first time for Panxi ilmenite. The newly developed route has passed the evaluation of Panzhihua Iron and Steel Company, and was employed by the company to establish 10 kt/a pilot plant, as shown in Fig. 4. After nearly 3 years’ design, construction and commissioning, the pilot plant achieved full capacity operation, where not only the TiO2 content of the upgraded product reaches over 90% with CaO+MgO less than 1.5%, but also the particle size remains unchanged after leaching. Consequently, a while set of new technology has been developed for upgrading Panxi ilmenite to synthetic rutile.

2. Process intensification for gas-solid fluidization

The team has worked for many years on process intensification for gas-solid fluidization and the achievements obtained include: (1) The fluidization of Geldart group C powders has been intensified by an external magnetic field for the first, where various kinds of group C powders showed smooth fluidization with external magnetic fields. Consequently, magnetically assisted fluidization has been proved to be a general intensification method for the fluidization of group C powders. A mechanism based on the chain formation and chain splitting bubbles in magnetic fields has been proposed for the magnetic fluidization and based on which a mathematic model has been developed. The magnetic fluidization has been applied to improve the efficiency of CH4-CO2 reforming and CH4 methanation using CO-H2. (2) A bubbling fluidization combined with fast fluidization method has been developed to intensify magnetizing roasting process for low grade iron ore particles with wide particle size distribution. It has been shown that roasting efficiency can be much

39

improved due to better residence time fitting and the roasting temperature can be reduced from 800-900℃ to 450-500 ℃, while in the meantime the magnetizing rate can be improved from 75% to 85%. (3) Internals were employed to intensify the reduction roasting of Panxi ilmenite, where the reduction rate was improved from less than 80% to 90%.

3. New technology for low grade mineral reduction

To apply the fundamental achievements in industrial scale, key technologies, like powder preheating, feeding/discharging, roasted ore cooling and stable combustion of low heat-value off-gas etc., have been developed. With the key technologies, a 100 kt/a magnetizing roasting pilot has also been established and successful ly commissioned for low grade iron ore(Fig.5). After the successful running of the pilot plant, many companies, including the world famous iron and steel company-POSCO, come to seek cooperation. After negotiation, we selected Jiutai Co. Ltd. as the cooperation partner, where a joint venture, with the total investment of 50 million RMB by Jiutai Co. Ltd., has been established to commercialize the technology. The joint venture is now implementing a 200 kt/a pyrolusite roasting project in Yunnan province (Fig. 6).

Fig. 5. 100kt/a pilot plant for magnetizing roasting of low grade iron ore

Fig.6. 200kt/a pilot plant for pyrolusite reduction

Selected Publications and Achievements

Qingshan Zhu, Hongzhong Li, Hua Tong and Tao Zhou, Process intensification for the fluidization of fine powders, 2nd Award, from China Chemical and Petrochemical Association, 2012Chao Lei, Qingshan Zhu and Hongzhong Li, Experimental and theoretical study on the fluidization behaviors of iron powder at high temperature, Chem. Eng. Sci., 118 (2014) : 59-69Qingshan Zhu, Jianbo Zhang, Hongzhong Li, Influence of phase and microstructure on the rate of hydrochloric acid leaching for pretreated Panzhihua ilmenite, Particuology, 14 (2014) : 83-90Yingce Wang, Zheng Zou, Hongzhong Li, Qingshan Zhu, A new drag model for TFM simulation of gas-solid bubbling fluidized beds with Geldart-B particles, Particuology, 15 (2014): 151-159Chao Lei, Tao Zhang, Jianbo Zhang, Chuanlin Fan, Qingshan Zhu and Hongzhong Li, Influence of content and microstructure of deposited carbon on fluidization behavior of iron powder at elevated temperatures, ISIJ Int., 54 (2014): 589-595.Tao Zhang, Chao Lei, Qingshan Zhu, Reduction of fine iron ore via a two-step fluidized bed direct reduction process, Powder Technol., 254 (2014) : 1-11.Changjin Li, Hongzhong Li, Qingshan Zhu, A hydrodynamic model of loop-seal for a circulating fluidized bed, Power Technol., 252 (2014) : 14-19.Xiaolin Lv, Hongzhong Li, Qingshan Zhu, Simulation of gas-solid in 2D/3D bubbling fluidized beds by combining the two-fluid model with structure-based drag model, Chem. Eng. J., 236 (2014) : 149-157.Jianbo Zhang, Gengyu Zhang, Qingshan Zhu, Chao Lei, Zhaohui Xie, Hongzhong Li, Morphological changes and reduction mechanism for the weak reduction of the pre-oxidized Panzhihua ilmenite, Metall. Mater. Trans. B, 45(2014) : 914-922.

1.

2.

3.

4.

5.

6.

7.

8.

9.

40

Baolin Hou, Hailong Tang, Haiying Zhang, Guoqiang Shao, Hongzhong Li and Qingshan Zhu, Experimental and theoretical investigation of mass transfer in a circulating fluidized bed, Chem. Eng. Sci., 102 (2013) : 354-364Zheng Zou, Hongzhong Li, Qingshan Zhu and Yingce Wang, Experimental study and numerical simulation of bubbling fluidized beds with fine particles in two and three dimensions, Ind. Eng. Chem. Res., 2013: 52, 11302-11312Jianbo Zhang, Qingshan Zhu, Zhaohui Xie, Chao Lei, Hongzhong Li Morphological changes of Panzhihua ilmenite during oxidation treatment, Metall. Mater. Trans. B, 44 (2013): 897-905Qingshan Zhu, Rongfang Wu and Hongzhong Li, Direct reduction of hematite powders in a fluidized bed reactor, Particuology, 11 (2013): 294-300Pengcheng Li, Jun Li, Qingshan Zhu, Lijie Cui and Hongzhong Li, Effect of granulation on the activity and stability of a Co-Al2O3 aerogel catalyst in a fluidized-bed reactor for CH4-CO2 reforming, RSC Advances, 3 (2013): 8939-894615.Jun Li, Li Zhou, Qingshan Zhu, and Hongzhong Li, Enhanced methanation over aerogel NiCo/Al2O3 catalyst in a magnetic fluidized bed, Ind. Eng. Chem. Res., 2013: 52, 6647-6654

Research Professors

Prof. Hongzhong Li was born in 1941 and graduated from the Department of Chemical Engineering, Taiyuan University of Technology in 1965. He worked as a Assistant Fellow and Assistant Professor at Institute of Coal Chemistry (ICC), CAS, Taiyuan, Shanxi Province, China (1965-1978). He obtained his MS degree from the University of Science and Technology of China in 1981 and his Ph. D. degree from the ICM, CAS in 1986. He worked as a Postdoctoral Fellow at the Department of Chemical Engineering, University of British Columbia (UBC), Canada (1986-1988). He has published more then 200 papers, 5 chapters and 4 books. He was authorized 10 China Practical Patents and 4 China Invention Patents. He won the Best Paper Prize at the 10th International Conference on Fluidized Bed Combustion in 1989 in San Francisco, the First Class Nature Science Prize and the Second Class Nature Science Prize awarded by Chinese Academy of Sciences in 1999 and 1997 respectively, three First Class Prizes of Science and Technology Progress awarded by the Chinese Society of Petroleum and Chemical Industries in 2009 and 2012, and the Book Prize of China

10.

11.

12.

13.

14.

Press Government Prizes awarded by News and Press Ministry of China in 2010 for the “Handbook of Fluidization” edited by Mooson Kwauk and Hongzhong Li.

AffiliationsMember of Chinese Academy of Sciences;Fellow of Royal Society of Chemistry;Director of Academic Committee, Institute of Process Engineering, CAS; Member of the standing council of Chinese Society of Particuology; Member of the standing council of the Chemical Industry and Engineering Society of China; Member of the editorial boards of Particuology, Computers and Applied Chemistry, Journal of Engineering Studies, and the advisory editorial boards of China Powder Science and Technology, Chinese Journal of Process Engineering, and Chemical Engineering (China).

Research InterestsThe prediction and optimal control of the local structure in gas-solids fluidized beds; Relationship among local structure; Mass transfer; Heat transfer; Reaction rate; Computer simulation of fluidized bed reactors and their scale-up.

41

Prof. Qingshan Zhu (Team Leader) was born in 1969 and received his Ph.D. degree in Reactor Engineering and Safety from Tsinghua University in 1997. He was a postdoctoral fellow at Kyushu National Industrial Research Institute, Japan in 1998-2000 and Eindhoven University of Technology, the Netherlands in 2000-2002. He became a full professor and at Institute of Process Engineering, Chinese Academy of Sciences (CAS) since April 2002 with the support of the so-called “100 Hundred Talents Program of CAS”. He is deputy director of Institute of Process Engineering, CAS (2013) and the executive deputy director of the State Key Laboratory of Multiphase Complex System, Ministry of Science and Technology, China. He has published over 90 SCI papers, and held 27 patents. He was awarded the NSFC Distinguished Youth Scholar in 2013.

AffiliationAssociate Editor-in-chief, Chinese Journal of Process Engineering (2004–present)Advisory Board Member, Particuology (2003- present)Advisory Board Member, International Review in Chemical Engineering (2009- present)Editorial Board Member, Chinese Journal of Powder Technology (2012-present)Editorial Board Member, Iron Steel Vanadium Titanium (2011-present)

Research InterestsFluidization; Mineral processing: Process intensification; Scaleup principle;

Prof. Xuchen Lu, born in 1964, got his B. Sc in 1986 from Jingdezhen Institute of Ceramics, and MSc in 1995 and Ph.D in 1998 both from Tianjin University. He has been a professor of materials science and engineering at Institute of Process Engineering, CAS since 2006. He is mainly engaged in high-efficient technology and process for materials preparation from natural minerals. He developed a new method of preparing zeolites using coal-series kaolin from a coalfield, such as nano-micro ZSM-5, SAPO-n and A zeolite etc.. He also proposed the complex salts-solid solution dehydration method and successfully prepared the anhydrous MgCl2 molten salts for electrolyzing magnesium metal and its alloys using bischofite by the method. He has published over 40 papers and has gotten over 30 patents. He won the Government Special Allowance of the State Council in 2005 and won excellent Worker of Chinese Academy of Sciences.

AffiliationsEditorial board member, Material SciencesReviewer, Powder Tech., Applied Clay Sci., and Composites Part A.Committee member, Advisory Committee of Science and Technology of Inner Mongolia

Research InterestsHigh-value utilization technology for non-metallic minerals; Preparing magnesium alloys from the brine containing MgCl2 or magnesite and synthesizing micro- and meso-porous materials and inorganic-organic nanocomposite materials from clay minerals.

42

Prof. Zhaohui Xie,born in 1963, got his M. Eng in 1990 from South China University of Technology, and M. Sc in 2002 from Colorado University at Boulder, USA. He has been a professor at Institute of Process Engineering, CAS, since 2008. He is mainly engaged in application of fluidization technology in metallurgical industry. As principal designer, he took part in developing a series of new processes, for high-efficient separating Vanadium, Titanium, Manganese and so on, from the ores. Most of them have been put into operation. As author of over thirty journal papers and inventor of thirteen patents, he is working on one of the most challenging technology in the world-direct reducing iron ore by fluidized bed, and such a pilot plant is under construction.

Research InterestsFluidized-bed reactor and engineering; Inorganic non-metal materials.