@inproceedings{EckertDasguptaAy, author = {Eckert, Karl-Andreas and Dasgupta, Sunanda and Ay, Peter}, title = {Novel techniques to optically characterize melt crystallization kinetics of high oleic sunflower oil based fatty acid mixture}, series = {Book of Abstracts of the 7th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry Karlsruhe, March 23-25, 2014}, booktitle = {Book of Abstracts of the 7th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry Karlsruhe, March 23-25, 2014}, publisher = {abiosus e.V. Conferences}, address = {Karlsruhe, Germany}, abstract = {The rising applications of enriched unsaturated fatty acid fractions are significantly increasing the need for a cheap method of manufacturing such fractions. Melt crystallization is an established method for purification and enrichment of desired fractions from mixtures [1, 2, 3]. Enrichment of such natural unsaturated fractions by melt crystallization processes has already been proved effective in prior investigations [1, 2]. Since then many analytical and investigative methods have been applied on various natural plant oil based poly-unsaturated fatty acid (PUFA) mixtures to generate the much needed fundamental melt crystallization data [1]. One such method is the use of in-situ polarized light microscopy [1, 4, 5]. Some of the important parameters affecting the melt crystallization of PUFA mixtures are nucleation and crystal growth rate. To be able to observe and visualize these micro-scale phenomena, circular polarized transmitted light microscopy was applied. A tempered chamber (Linkam LS 120) containing the sample between two object slides was placed right within the microscope camera setup (Leica DM RME and Leica DFC 500) with a viewing window. With respect to the transmitted light, the sample was placed between two circular polarized filters such that the system is calibrated for optimal visualization. Unlike linear polarization, in this method every crystal independent of its alignment in the sample, delivers an interference color different from its background. This way, the entire crystal structure could be clearly separated from the melt. Nucleation and crystal growth rate of a high oleic sunflower oil based PUFA was measured using this method at 5K supercooling and 10K/min cooling rate. Growth curves for total crystal area and number of crystals were analyzed and illustrated graphically. A typical S- curve is observed for both the cases starting with a lag phase followed by an exponential growth phase and ending in a saturation phase.}, language = {en} } @inproceedings{DasguptaAy, author = {Dasgupta, Sunanda and Ay, Peter}, title = {In-situ monitoring and induction time measurements during melt crystallization of plant based fatty acid mixtures in V-form reactor}, series = {6th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry Karlsruhe, March 17-19, 2013}, booktitle = {6th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry Karlsruhe, March 17-19, 2013}, publisher = {abiosus e.V. Conferences}, address = {Karlsruhe, Germany}, abstract = {Enriched plant based unsaturated fatty acid mixtures are increasingly finding applications in various fields like those of production of bio-fuels and polymerization of epoxy resins. In the case of production of epoxy resins, they are highly advantageous due to the presence of multiple double bonds in the fatty acids which provide opportunities for cross linking by substitution. On the other hand, bio-fuels need raw materials with very low crystallization temperatures. This special property can also be attributed to these enriched unsaturated fractions due to their weak inter-molecular interactions owing to the kink in their structures. Melt crystallization has long been established as an optimal method for purification and enrichment of fractions from mixtures [1,2]. Previous studies have shown promising results with regard to enrichment of unsaturated fractions by melt crystallization processes [1]. Melt crystallization kinetics of two plant based poly-unsaturated fatty acid mixtures have been investigated in this study [3]. A high oleic and a high linoleic fatty acid mixture were chosen for comparison purposes. A V-form reactor was developed for optimal in-situ analysis with the help of the focused beam reflectance measurement (FBRM®, Mettler Toledo Ltd., Switzerland) instrument [3]. Enhanced heat transfer especially to deal with the heat given out during crystallization was enabled through minimal volume of sample, optimized mixing and the special shape of the reactor. Important parameters like induction time, mixing speed, etc have been determined and compared as functions of degree of supercooling and composition of PUFA mixtures. In accordance to theory, the induction times in both the cases decreased with increasing supercooling and mixer speed. On the other hand, the high linoleic fatty acid mixture required much higher supercooling (4.4K to 5.4K) than the high oleic mixture (2.2K to 3.2K) for favorable induction times.}, language = {en} } @inproceedings{DasguptaAy, author = {Dasgupta, Sunanda and Ay, Peter}, title = {Enrichment of unsaturated fractions in a Linseed oil based fatty acid mixture by melt crystallisation}, series = {5th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry, Karlsruhe, Germany}, booktitle = {5th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry, Karlsruhe, Germany}, pages = {S. 93}, abstract = {Enriched plant based unsaturated fatty acid mixtures are increasingly finding applications in various fields like those of production of bio-fuels and polymerization of epoxy resins. In the case of production of epoxy resins, they are highly advantageous due to the presence of multiple double bonds in the fatty acids which provide opportunities for cross linking by substitution. On the other hand, bio-fuels need raw materials with very low crystallization temperatures. This special property can also be attributed to these enriched unsaturated fractions due to their weak inter-molecular interactions owing to the kink in their structures. Melt crystallization has long been established as an optimal method for purification and enrichment of fractions from mixtures [1,2]. Previous studies have shown promising results with regard to enrichment of unsaturated fractions by melt crystallization processes [1]. Melt crystallization kinetics of two plant based poly-unsaturated fatty acid mixtures have been investigated in this study [3]. A high oleic and a high linoleic fatty acid mixture were chosen for comparison purposes. A V-form reactor was developed for optimal in-situ analysis with the help of the focused beam reflectance measurement (FBRM®, Mettler Toledo Ltd., Switzerland) instrument [3]. Enhanced heat transfer especially to deal with the heat given out during crystallization was enabled through minimal volume of sample, optimized mixing and the special shape of the reactor. Important parameters like induction time, mixing speed, etc have been determined and compared as functions of degree of supercooling and composition of PUFA mixtures. In accordance to theory, the induction times in both the cases decreased with increasing supercooling and mixer speed. On the other hand, the high linoleic fatty acid mixture required much higher supercooling (4.4K to 5.4K) than the high oleic mixture (2.2K to 3.2K) for favorable induction times. References [1] S. Dasgupta, N. Dreiack, P. Ay, presented at the 5th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry (Eds: J.O. Metzger, M.A.R. Meier), Karlsruhe 2012 [2] G.F. Arkenbout, Melt Crystallization Technology, Technomic Publishing Company Inc., Pennsylvania 1995 [3] S. Xu, Master thesis, Chair of Mineral Processing, Processing of Biogenous Resources, Brandenburg University of Technology, Cottbus 2010}, language = {en} } @misc{DasguptaRettigAy, author = {Dasgupta, Sunanda and Rettig, Florian and Ay, Peter}, title = {Nucleation kinetics during melt crystallization of plant based high oleic and linoleic polyunsaturated fatty acid mixtures}, series = {Crystal Growth \& Design}, volume = {16}, journal = {Crystal Growth \& Design}, number = {2}, issn = {1528-7505}, doi = {10.1021/acs.cgd.5b01432}, pages = {861 -- 866}, abstract = {Nucleation kinetics of high linoleic and high oleic polyunsaturated fatty acid (PUFA) mixtures were investigated during melt crystallization by means of an Focused beam reflectance measurement (FBRM) sensor. Samples were analyzed thermally and chemically in the Differential Scanning Calorimeter (DSC) and Gas Chromatograph (GC) respectively. Investigations showed that a high oleic content in the PUFA mixtures lead to higher induction times, τi. Unlike previous investigations, a clear relation between τi and cooling rates was established. τi increases with increasing cooling rates and decreasing supercooling. Activation energies of nucleation, ∆Gc' were determined by means of the Fisher Turnbull equation wherein ∆Gc' decreases exponentially with increasing supercooling. Investigations and further evaluations conclude that while the plot establishes the effect of supercooling on ∆Gc' , it does not incorporate the effects of molecular diffusion or the cooling rate. Hence, 3D modeling was performed to visualize the combined effects of cooling rate and supercooling on induction time.}, language = {en} } @misc{OyegbileAyNarra, author = {Oyegbile, Benjamin and Ay, Peter and Narra, Satyanarayana}, title = {Optimisation of micro-processes for shear-assisted solid-liquid separation in a rotatory batch flow vortex reactor}, series = {Journal of Water Reuse and Desalination}, volume = {6}, journal = {Journal of Water Reuse and Desalination}, number = {1}, doi = {10.2166/wrd.2015.057}, pages = {125 -- 136}, abstract = {This paper reports the study of micro-processes in a novel pre-treatment technique using a pellet forming batch flow vortex reactor of cylindrical shape that consists of axially revolving rotor plates between fixed stator plates. The suspension was first mixed with high molecular weight synthetic polymers by stirring for approximately 50 seconds and then agitated for 20 minutes. The process was optimised for a number of operating conditions including polymer type and dosing regimen, rotation speed, wall-plate gap distance, residence time and suspension filling method. The results of the investigation show that optimising a number of process variables that influence floc formation and growth, along with specific apparatus construction and geometry, help to maintain the suspension in a metastable state that is crucial for the formation of pellet-like compact agglomerates with better dewaterability and uniform aggregate size. A maximum dry solids content of 28.3\% after gravity dewatering through a 0.5 mm sieve was recorded during the investigation, with a maximum particle removal efficiency of 97.5\%.}, language = {en} } @misc{EckertDasguptaSelgeetal., author = {Eckert, Karl-Andreas and Dasgupta, Sunanda and Selge, Benjamin and Ay, Peter}, title = {Solid liquid phase diagrams of binary fatty acid mixtures - Palmitic/stearic with oleic/linoleic/linolenic acid mixture}, series = {Thermochimica Acta}, volume = {Vol. 630}, journal = {Thermochimica Acta}, issn = {0040-6031}, doi = {10.1016/j.tca.2016.02.008}, pages = {50 -- 63}, abstract = {The solid liquid phase diagrams of binary mixtures of the five main saturated and unsaturated fatty acids present in most edible plant oils have been determined in this paper. These binary mixtures comprise of a saturated fatty acid, either palmitic (C16:0) or stearic (C18:0) and an unsaturated one, oleic (C18:1), linoleic (C18:2) or linolenic (C18:3) acid. Differential scanning calorimetry (DSC) was used to obtain an overview of the solid liquid transition behaviour including the metastable ranges of these mixtures. In order to describe all the phase transformations in these systems, the boundary functions have been determined and compared. Phase diagrams determined, illustrate characteristic behaviour in accordance to literature. This work specifically focuses on to describe the solid liquid transitions of the mixtures and not on every single transition or reaction. This paper contributes to the elucidation of the phase behaviour of these important mixtures which are applied in diverse industries.}, language = {en} } @misc{DasguptaDreiackAy, author = {Dasgupta, Sunanda and Dreiack, Nadine and Ay, Peter}, title = {Melt crystallization kinetics for enrichment of highly unsaturated fatty acid fractions based on Linseed oil}, series = {Journal of Environmental Research And Development}, volume = {11}, journal = {Journal of Environmental Research And Development}, number = {1}, issn = {0973-6921}, pages = {1 -- 6}, abstract = {Naturally occurring plant based fats and oils have a huge potential as renewable resources to synthesize chemically new products apart from being widely used as ingredients in various kind of food and cosmetics. Oils are triglycerides which are basically tri-esters made of glycerol and three fatty acids. The latter finds application on one hand as raw material for the polymerization of epoxy resins whereas on the other in the manufacturing of biodiesel amongst others. Melt crystallization as a method to enrich a fatty acid mixture with higher unsaturated fractions is becoming increasingly established. A polyunsaturated fatty acid mixture with high concentration of linolenic acid (C 18:3) was chosen for this work. This linolenic oil fatty acid rich mixture was subjected to different temperature profiles in order to optimize maximum yield of unsaturated fatty acid in the mother liquor post isothermal centrifugal separation. The influence of the temperature profile on the quality of the desired product was thereby investigated. To examine the exact composition of the resulting product several analytical methods like Differential Scanning Calorimetry (DSC) and Gas Chromatography (GC) were developed and performed. Product compositions with a total saturated content (C16:0 - palmitic acid and C18:0 - stearic acid) of below 3\% was achieved successfully.}, 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} } @inproceedings{MarkowskiAyPempeletal., author = {Markowski, Jens and Ay, Peter and Pempel, Harry and Logsch, Florian}, title = {Recycling of metal-coated plastic parts from end-of-life-vehicles (ELV) with biotechnological methods}, 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 191}, abstract = {Due to the European Directive 2000/53/EC on end-of-life-vehicles, from 2015 on more than 95\% of car materials have to be recycled. In order to recycle the materials back into the economic cycle, it is necessary to produce products with high quality and purity. Plastic components in cars, which are coated with metals by vapour deposition or electroplating, have a wide circulation (e.g., as cladding panel or trim strip for interiors and exteriors). In the end-of-life-vehicle recycling process, these plastic-metal composites are not considered in usual technologies (car shredder) and are not separated from Automotive Shredder Residue. These parts can be separated by optical or HF-detection sorting and then introduced to a specific treatment. Experiments with a specially developed bioleaching configuration showed that the thin coatings, which consist mainly of copper, nickel and chromium, can be removed efficiently from the polymer base materials by a bioleaching solution with Acidothiobacillus ferrooxidans as a leaching agent. The solution used was produced in special fermenters with a 9K-nutrient salt media. During the bioleaching process at 35°C maximum temperature, most of the copper is dissolved and the other metals accumulate as metal sludge. The bacterial cultures based on A. ferrooxidans are robust and resilient. After a 48-hour bioleaching period while the composites were stirred regularly with ventilation, the plastic particles were completely free from metallic coatings. The metal components are separated for further use: undissolved components (mainly Ni and Cr) are separated by decantation of the solution; dissolved copper recovey is carried out by cementation of copper. The cementated solid contains ~98\% Cu, along with small amounts of other metals. With the bioleaching process, good separation and re-utilization of the metallic coatings is possible. The cleaned plastic parts were prepared by compounding for new applications with injection-moulding.}, language = {en} } @misc{EckertDasguptaSelgeetal., author = {Eckert, Karl-Andreas and Dasgupta, Sunanda and Selge, Benjamin and Ay, Peter}, title = {Construction and comparison of solid liquid phase diagrams of binary sat-sat and unsat-unsat fatty acid mixtures comprising two of palmitic/stearic/oleic/linoleic/linolenic acid}, series = {Journal of Environmental Research And Development}, volume = {10}, journal = {Journal of Environmental Research And Development}, number = {4}, issn = {0973-6921}, pages = {10}, abstract = {In this paper, binary phase diagrams of the five main fatty acids present in edible oil based mixtures are shown. While previously the binary systems of one saturated and one unsaturated acid were investigated, in this work the binary mixtures comprise of palmitic (C16:0) and stearic acid (C18:0) or a binary mixture of oleic (C18:1), linoleic (C18:2) or linolenic acid (C18:3). In order to obtain the phase diagrams with all the solid liquid and solid phase transitions, the mixtures were analyzed by means of Differential Scanning Calorimetry (DSC). Phase change boundary functions based on thermodynamic models and experimental values were fitted and compared. The phase diagrams obtained show behaviors in good agreement to literature. The paper contributes to the deeper understanding of the essential phase change effects during industrial crystallization processes.}, language = {en} } @misc{KloseReinholdLogschetal., author = {Klose, Markus and Reinhold, Romy and Logsch, Florian and Wolke, Florian and Linnemann, Julia and Stoeck, Ulrich and Oswald, Steffen and Uhlemann, Martin and Ballach, Juan and Markowski, Jens and Ay, Peter and Giebeler, Lars}, title = {Softwood lignin as a sustainable feedstock for porous carbons as active material for supercapacitors using an ionic liquid electrolyte}, series = {ACS Sustainable Chemistry \& Engineering}, volume = {5}, journal = {ACS Sustainable Chemistry \& Engineering}, number = {5}, pages = {4095 -- 4102}, language = {en} } @inproceedings{MarkowskiPempelAy, author = {Markowski, Jens and Pempel, Harry and Ay, Peter}, title = {Recovery of nickel-containing coatings with hydro-biotechnological methods}, series = {COM 2017, Conference of Metallurgists (MetSoc), The 56th Annual Conference of Metallurgists, hosting World Gold and Nickel-Cobalt, August 27-30, 2017, Hyatt Regency Vancouver, British Columbia, Canada}, booktitle = {COM 2017, Conference of Metallurgists (MetSoc), The 56th Annual Conference of Metallurgists, hosting World Gold and Nickel-Cobalt, August 27-30, 2017, Hyatt Regency Vancouver, British Columbia, Canada}, publisher = {Canadian Institute of Mining, Metallurgy and Petroleum}, address = {Vancouver}, isbn = {978-1-926872-36-0}, abstract = {Metal-coated thermoplastic parts find more and more functional and aesthetic applications in the interior and exterior of cars. The vapor-deposited or electroplated coatings are usually composed of a plurality of nickel- and chromium-containing layers, which are applied to copper-containing carrier layers on the polymers. Previously, recycling processes are mainly focussed at the recovery or thermal utilization of the plastics. Targeted and selective recycling of the metallic coatings is usually not carried out. Together with several SME, BTU developed a process, in which a complete and separate recovery of all components in high purity is possible with biotechnological methods. The bioleaching is carried out with iron and sulfur-oxidizing bacteria, esp. Acidithiobacillus ferrooxidans. The copper-containing layers are dissolved in the solution; chromium- and nickel-containing particles are precipitated as solids. After the bioleaching, a mechanical separation of the individual metal-containing components and their separate workup are carried out. End-products are metallic copper, a nickel- and chromium-containing solid and the cleaned plastics. The bioleaching ensures a high purity of the end products. Through the use of bacteria, which are also found in nature, the process is environmentally friendly. Compared to chemical leaching using inorganic acids, considerably shorter leaching times can be achieved. In addition to the optimization of the leaching process, the R/D-project also includes the development and testing of the apparatus technology.}, language = {en} } @misc{EckertDasguptaSelgeetal., author = {Eckert, Karl-Andreas and Dasgupta, Sunanda and Selge, Benjamin and Ay, Peter}, title = {Novel model for the prediction of SSLE temperatures and crystallization paths of any mixture containing palmitic, stearic, oleic, linoleic and linolenic acid}, series = {Thermochimica Acta}, volume = {652}, journal = {Thermochimica Acta}, issn = {0040-6031}, doi = {10.1016/j.tca.2017.03.015}, pages = {126 -- 140}, abstract = {A mathematical model for the prediction of phase change temperatures and crystallization paths for mixtures consisting of palmitic (P), stearic (S), oleic (O), linoleic (L) and linolenic acid (Ll) in any distribution is presented in this paper. This model is based on the information gathered from modeled ternary phase diagrams, namely PSO, PSL, PSLl and OLLl, that were based on experimental binary phase diagrams of all possible combinations of these fatty acids. These experimental binary phase diagrams were obtained by means of differential scanning calorimetry and mathematical function fitting, within which the eutectic region of binary palmitic/stearic with oleic/linoleic/linolenic acid was investigated in detail. The basic mathematical model used was previously shown in literature which delivered good results for such systems. The importance of the developed model was then justified by investigations on real and composed synthetic fatty acid mixtures, where a high accuracy of the predicted temperatures could be shown for the technically relevant liquidus and solidus temperatures. A satisfying prediction for thermal events below the first solidus line could be reached as well. This work directly contributes to an enhanced understanding of the thermodynamic and kinetic background of such important mixtures applied in diverse products and industries, thereby showing a large optimization potential for crystallization technologies.}, language = {en} } @inproceedings{DasguptaGlaserAy, author = {Dasgupta, Sunanda and Glaser, Claudia and Ay, Peter}, title = {SLE diagram for a high oleic palm oil based fatty acid mixture at low saturated content}, series = {9th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry, March 19-21, 2017, Karlsruhe, Germany}, booktitle = {9th Workshop on Fats and Oils as Renewable Feedstock for the Chemical Industry, March 19-21, 2017, Karlsruhe, Germany}, publisher = {Abiosus e.V.}, address = {Oldenburg}, abstract = {Vegetable oils and their derivatives are increasingly replacing mineral oils in their applications.[1,2] Among other constituents in vegetable oil, both saturated and unsaturated fractions are important raw materials. The latter possesses double bonds which can provide as substrates or raw materials for various chemical industries.[3] Fractionation of these oils or as in our case the Poly-Unsaturated Fatty Acid (PUFA) mixture is required so as to generate favorable compositions according to applications. Generation of Solid Liquid Equilibrium (SLE) phase diagrams for real mixtures is extremely important to enable a thorough understanding of the thermodynamics of the fractionation process of crystallization. The PUFA mixture was fractionated in a multistage scrubbing layer crystallizer. The product was put into a decanter centrifuge so as to fractionate them into mother liqor and crystal fraction. The temperature in the jacket was maintained such that △T< 5K from the liquidus point obtained from the Differential Scanning Calorimeter (DSC) thermal analyses. Each crystallizer was also maintained at a temperature 5K below the previous one. This way a slow and successive cooling of the PUFA was achieved such that probes from different fraction could be obtained. They were analyzed thermally and chemically in the DSC and Gas Chromatography - Flame Ionization Detector (GC-FID) setup respectively.[4] Similar to previous literature as in [5], technically relevant partial SLE diagrams for high oleic palm oil was created by fractionating the mixture in a scrubbed layer crystallizer along with their metastable range were determined.[6]}, language = {en} } @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} }