@inproceedings{LogschGlaserBalzetal., author = {Logsch, Florian and Glaser, Claudia and Balz, Jessica and Ay, Peter and Leiker, Matthias and Heiduschke, Rene}, title = {Experimental studies of the pelletizing-flocculation process of ironhydroxide containing suspensions in a Taylor-Couette-Reactor}, series = {Abstracts of the XXIX International Mineral Processing Congress : 17-21 september, 2018}, booktitle = {Abstracts of the XXIX International Mineral Processing Congress : 17-21 september, 2018}, edition = {1. Auflage}, publisher = {Ore and Metals, Publishing House, Moscow}, address = {Moscow}, isbn = {978-5-98191-086-9}, pages = {189}, abstract = {The treatment of iron-hydroxide-containing water from ground water and surface water is achieved by a combination of the process steps of flocculation and subsequent mechanical dewatering. The aim is to create solid pellet structures by extending the structure forming flocculation process with a build-up pelletizing process which can be transferred directly into a drying unit. A Taylor-Couette-reactor (diameter of the inner cylinder - 40 mm, gap width - 5 mm) was used for these experimental studies. To produce the necessary flow profile the inner cylinder was rotated at a speed of 230 rpm. The iron hydroxide-containing suspension (dry matter content: 2 mass \%) was added simultaneously with the addition of a cationic high-molecular flocculant in various flocculant dosages and residence times of 5 to 15 min. The pellets were examined for parameters such as geometric dimensions, dry substance content and dewatering behaviour. As the results show, there is a direct relationship between the residence time and the geometric dimensions of the pellets. After a residence time of 5 min, round pellets with an average diameter of 6 mm were formed. With an increase in the residence time up to 15 min, a compaction of the pellets could be observed, which resulted in an increase in the dry substance content of 8.0 to 11.2 mass \% on average. After completion of the pelletizing process, the pellets were mechanically dewatered by filtration. By applying this innovative wet pelletizing of iron-hydroxide containing suspensions in a Taylor-Couette-reactor, it is possible to carry out the process of flocculation combined with the pellet formation with simultaneous pellet compaction in a single process step. The resulting pellet structures are distinguished from conventional floc structures by an improved water discharge capacity. After classification the pellets can be marked directly as easy-to-handle bulk material, suitable as feedstock in percolation columns for the purification of contaminated fluid streams}, language = {en} } @inproceedings{AyGlaserLogschetal., author = {Ay, Peter and Glaser, Claudia and Logsch, Florian and Narra, Satyanarayana and Gemende, Bernhard and Gerbeth, Anja and Riedel, Tobias and Pausch, Nicole and Leiker, Matthias and B{\"a}de, Bianka and Heiduschke, Rene}, title = {Micro-structured Iron (III) hydroxide agglomerates with high porosity as adsorbents}, series = {Proceedings of the XXVIII International Mineral Processing Congress (IMPC 2016), September 11-15, 2016, Qu{\´e}bec City, Canadian Institute of Mining, Metallurgy and Petroleum}, booktitle = {Proceedings of the XXVIII International Mineral Processing Congress (IMPC 2016), September 11-15, 2016, Qu{\´e}bec City, Canadian Institute of Mining, Metallurgy and Petroleum}, isbn = {978-1-926872-29-2}, pages = {Paper 263}, abstract = {This study focusses on the production of micro-structured agglomerates with high porosity from iron (III)-hydroxide-containing materials as adsorbent. A fractal structure of the agglomerates was created through a two-stage agglomeration process. Developing porous structures was necessary to increase the adsorption capacity. Various materials were used for the agglomeration experiments: i) filter cake (dry matter content 23 to 27 wt.-\%); ii) FerroSorp®DGμ, a product which is already being used commercially for various applications in water cleaning. These materials in the pristine state have different characteristics such as dry matter content and particle size distribution. The desired optimised agglomerates can be achieved with the help of additives or binders, respectively. Additionally, the agglomeration process parameters play a vital role. In order to produce agglomerates with high porosity, the process was carried out in two steps. Firstly, FerroSorp®DGμ (d90 < 30 µm) was agglomerated jointly with the aforementioned filter cake in an Eirich intensive mixer (particle size range 125 µm < d90 < 500 µm). The second agglomeration step post drying was carried out in a pelletisation disc or in an Eirich intensive mixer with the addition of polymeric binders (up to particle sizes ranging from 2 to 4 mm). Agglomerates were characterised both in short and long term loading tests using phosphate as model ion. Contact times were less than 10 min, similar to practical application in percolation columns, or more than 7 days, respectively. The results show that the agglomerates produced in the two-stage pelletisation process have more advantageous properties like better accessibility of the active sites obtained by specificly influencing the particle size distribution during the two-stage pelletisation process.}, language = {en} }