GERMAN TECHNOLOGY
The EIRICH mixing system: A rotating and inclined mixing pan with eccentric mixing tool produces excellent results for different tasks in material processing, in this case for the pelletisation of coal dust
presented new research on coal dust agglomeration carried out jointly with the Institute of Mineral Processing Machines at TU Bergakademie Freiberg. Pelletisation produces granules which are easy to dose, opening up completely new markets for their use. An EIRICH mixer was used for the production of the pellet feed.
The investigations by HAVER ENGINEERING have demonstrated that it is technically feasible for fine materials such as dusty hard coal fractions to be transferred in particle sizes which do not generate dust. Improvements in the characteristics of the material resulting from agglomeration in the HAVER Scarabaeus disc pelletiser, such as a uniform particle size distributions for the granules, improved flow and spreading properties, prevention of demixing, permeability adapted to requirements and very good dosing accuracy, open up new areas of application.
“ Many industries generate dust which is either a reusable substance( eg coal dust) in itself or still contains reusable substances( eg dust from metallurgical processes). To enable the reusable substances to be handled or to be recovered from dust, the dust has to be agglomerated; the experts refer to this as grain enlargement or transformation into lumps. The processes involved are granulation, pelletisation or compaction / briquetting, depending on the specific application. In practically every case the agglomeration process is preceded by a mixing process, and the process used by HAVER ENGINEERING for producing granulate material with the disc pelletiser is no exception.”
The cited reasons are as follows. The low inherent moisture in the dust generally means inadequate compactability; for recycling processes, other materials often have to be mixed in as well, eg carbon carriers. Hence the dust is mixed with liquids, binders and in many cases additives as well. As a general rule the volumes of dust being processed are large. There is therefore a premium on keeping the amount of binder to a minimum. In addition, the moisture content, binder and additives must be evenly distributed in order to achieve a product with sufficient homogeneity. Sludges also have to be used in many cases for moistening.
“ This is where the use of EIRICH mixing technology proves to be advantageous for users. Due to their design, mixing systems from EIRICH achieve a better distribution than other systems, which results in savings on additives and binders. The mixer used for the purpose comes in sizes from 1 litre to 3,000 litres and has just a single rotor tool; there is no need for highspeed, high-wear choppers as used in plowshare mixers. The rotor can – depending on the task – run at speeds of more than 30 m / s. This makes it possible to generate high shear forces and distribute liquids, binders and additives quickly.”
For build-up agglomeration on disc pelletisers or in drum pelletisers, the
University
of Science and Technology Beijing( USTB) will host the 20th International Seminar on Paste and Thickened Tailings( Paste 2017) in Beijing, 15-18 June 2017.
This is going to be the first Paste Seminar held in China which consumed nearly 50 % mining products of the world. The objective of Paste 2017 in Beijing is to allow academics, designers, practitioners, consultants and suppliers to exchange knowledge, experiences and lessons learnt in different case studies and projects around the world.
Welcome to Paste 2017! Delegates who register before or on 16 April, 2017 can enjoy the Early Bird Rate. More discount will be offered to authors whose final articles have been approved and all legitimate students. Delegates can register and pay registration fees for the Seminar online( www. paste2017. com).
The Organizing Committee of Paste 2017 welcomes the support of the mining, engineering, and environmental communities and invites your company to participate as a sponsor. Major sponsors, social sponsors and material sponsors are available. For more information, please visit www. paste2017. com.
Shenghua YIN
School of Civil and Resource Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing, China Tel: + 86( 10) 62334680 Fax: + 86( 10) 62333563 Email: paste2017 @ 126. com