Chemical Engineering & Technology

Cover image for Vol. 37 Issue 4

Early View (Online Version of Record published before inclusion in an issue)

Impact Factor: 1.366

ISI Journal Citation Reports © Ranking: 2012: 55/133 (Engineering Chemical)

Online ISSN: 1521-4125

Associated Title(s): Chemie Ingenieur Technik, ChemBioEng Reviews, Energy Technology

VIEW

  1. 1 - 21
  1. Research Articles

    1. Evaluation of Impact Velocity and Compression Force of Moist Zeolite 4A Granules at Breakage using an Equivalence Function

      Peter Mueller, Sergej Aman and Juergen Tomas

      Article first published online: 7 APR 2014 | DOI: 10.1002/ceat.201300792

      Thumbnail image of graphical abstract

      The mechanical properties of granules must be known to avoid problems during processing and transportation. Moist spherical zeolite 4A granules were tested by compression at a constant loading velocity until primary breakage. The granules were rectilinearly accelerated and impacted to achieve breakage. Compressive breakage force and impact breakage velocity distributions were determined.

    2. CFD-Discrete Element Method Simulations Combined with Compression Experiments to Characterize Stirred-Media Mills

      Stefan Beinert, Carsten Schilde, Greta Gronau and Arno Kwade

      Article first published online: 7 APR 2014 | DOI: 10.1002/ceat.201300716

      Thumbnail image of graphical abstract

      Micro-compression tests of single model aggregates and coupled CFD-discrete element method simulations are linked to improve the prediction of the dispersion progress in stirred-media mills. The dispersion efficiency is calculated by the stress energy distribution of an annular-gap mill and the breakage distribution of the particle system.

    3. Ultrafine Grinding of Limestone with Sodium Polyacrylates as Additives in Ordinary Portland Cement Mortar

      Katja Ohenoja, Sandra Breitung-Faes, Päivö Kinnunen, Mirja Illikainen, Juha Saari, Arno Kwade and Jouko Niinimäki

      Article first published online: 7 APR 2014 | DOI: 10.1002/ceat.201300707

      Thumbnail image of graphical abstract

      Nano-grinding of limestone in a stirred media mill is an interesting method for nano-CaCO3 production. More energy-efficient grinding of CaCO3 can be achieved by adding sodium polyacrylate with a low polydispersion index as grinding aid. Original Portland cement mortar tests were performed with ground nano-CaCO3 particles. The heat of hydration is accelerated.

  2. Reviews

    1. Mechanochemistry in Technology: From Minerals to Nanomaterials and Drugs

      Peter Baláž, Matej Baláž and Zdenka Bujňáková

      Article first published online: 7 APR 2014 | DOI: 10.1002/ceat.201300669

      Thumbnail image of graphical abstract

      Mechanochemical processing can effectively control and regulate the course of solid-state reactions. Possible applications of mechanochemistry in extractive metallurgy, materials engineering, and medicine are illustrated with several examples. Potential alterations of solid properties are described and the advantages and particularly attractive environmental aspects of these processes are explained.

    2. Progress and Challenges in Electrical Comminution by High-Voltage Pulses

      Fengnian Shi, Emmy Manlapig and Weiran Zuo

      Article first published online: 7 APR 2014 | DOI: 10.1002/ceat.201300660

      Thumbnail image of graphical abstract

      Comminution consumes about one third of the energy used by the mining industry. Therefore, improved methods for mineral comminution are continually being sought. A particle pre-weakening characterization method by single-particle/single-pulse test has been developed. Challenges in terms of facilities scaling-up, circuit design, generation of cracks, and downstream effects are discussed.

  3. Research Articles

    1. Air-Core Size Measurement of Operating Hydrocyclone by Electrical Resistance Tomography

      Arugonda Rakesh, Vakamalla T. S. R Kumar Reddy and Mangadoddy Narasimha

      Article first published online: 7 APR 2014 | DOI: 10.1002/ceat.201300672

      Thumbnail image of graphical abstract

      The air-core is one of the most important flow characteristics in hydrocyclones. Air-core profiles were measured by a dual-plane fast-response electrical resistance tomography system and high-speed camera. The influence of design and operating conditions of the hydrocyclone on air-core size is studied. Three reconstruction algorithms were adopted. Results are validated against simulations and camera data.

    2. Matrix Model Simulation of a Vertical Roller Mill with High-Efficiency Slat Classifier

      Jozsef Faitli and Peter Czel

      Article first published online: 7 APR 2014 | DOI: 10.1002/ceat.201300665

      Thumbnail image of graphical abstract

      Considering the continuously increasing industrial importance of vertical roller mills, a novel simulation and optimization method for operators of such equipment is described. Its suitability is based on a rather engineering than fundamental approach and on on-site sampling and tests. The complete technology is successfully simulated by a matrix model.

  4. Communications

    1. Influence of Different Grinding Devices on the Reactivity of Ground Granulated Blast Furnace Slag

      Martin Reformat and Horst-Michael Ludwig

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300653

      Thumbnail image of graphical abstract

      The replacement of ordinary produced cement by ground granulated blast furnace slag (GGBFS) in the cement production reduces negative impacts on the environment. By adequate fine grinding the reactivity of GGBFS as a cement linker substitution could be enhanced. The influence of grinding devices on the reactivity of GGBFS is investigated and evaluated.

  5. Research Articles

    1. Effect of Polydispersity Index on the Grinding Limits of Highly Concentrated Limestone Suspensions

      Katja Ohenoja, Juha Saari, Mirja Illikainen, Sandra Breitung-Faes, Arno Kwade and Jouko Niinimäki

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300415

      Thumbnail image of graphical abstract

      Ultrafine grinding of limestone in stirred media mills is an attractive method for nano-CaCO3 production. Effects of polydispersity index and doses of two sodium polyacrylates on the grinding limits of limestone suspensions were studied. Sodium polyacrylate with a low polydispersity index turned out to be an effective grinding aid for limestone.

    2. Optimal Positioning of the Circulating Load Input along the Tube Mill Length

      Vadim Mizonov, Vladimir Zhukov and Victor Zaitsev

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300539

      Thumbnail image of graphical abstract

      One of the key problems in improving the efficiency of grinding is how to match the particle size and the necessary grinding time. A model for optimizing the position of the circulating load input in a closed milling circuit with a tube mill is proposed. It is shown that such an optimum does exist and can yield a considerable gain in the circuit capacity.

    3. Modeling of Screening Processes with the Discrete Element Method Involving Non-Spherical Particles

      Harald Kruggel-Emden and Frederik Elskamp

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300649

      Thumbnail image of graphical abstract

      Despite many modeling advances, phenomenological models still lack the ability to represent dynamic processes within the unit operation sieving. Here, discrete element method simulations of complex-shaped particles on two batch apparatuses and a continuously operated sieve are performed. Phenomena related to sieving of non-spherical particles are investigated numerically.

    4. Reduction of Surface Roughness and Rounding of Limestone Particles in a Stirred Media Mill

      Ádám Rácz

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300671

      Thumbnail image of graphical abstract

      The rounded shape and smooth surface of particles is necessary for many processes. A stirred media mill was used in dry mode to produce rounded or smooth surface particles in a size range of a few hundred microns without significant size reduction. An evaluation method was created to show the effect of the milling parameters on the particle shaping in relation to the product-related stress model.

    5. Use of an Enhanced Stress Model for the Optimization of Wet Stirred Media Milling Processes

      Sandra Breitung-Faes and Arno Kwade

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300686

      Thumbnail image of graphical abstract

      An enhanced stress energy model is used for the prediction of optimum process parameters for inorganic materials in wet stirred media milling based on results for a different grinding material. Optimization of the process parameters leads to minimum wear values for a certain product fineness, especially for materials that are softer than the grinding media material.

    6. Dry Fine Grinding with Jet Mills: Potentials of Energy Optimization

      Sophie Schwarzwälder, Roland Nied and Hermann Sickel

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300692

      Thumbnail image of graphical abstract

      Application of single-stage, uncooled low-pressure compressors for jet milling offers an economical alternative to double-stage, cooled compressors for fine grinding. Stabilization during grinding provides an enormous potential for improvement. Selected examples demonstrate that the energy requirement can be reduced by a factor of > 2 with suitable stabilizers.

    7. Challenges in Nanogrinding of Active Pharmaceutical Ingredients

      André Bitterlich, Christina Laabs, Eike Busmannn, Arnaud Grandeury, Michael Juhnke, Heike Bunjes and Arno Kwade

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300697

      Thumbnail image of graphical abstract

      The influence of process parameters on product quality for the milling of the active pharmaceutical ingredients fenofibrate and cinnarizine was investigated. Besides the well-known challenge regarding stabilization of the newly formed (nano)particles, a further challenge occurred: the ripening of the cinnarizine crystals during or shortly after the milling process.

    8. Experimental and Computational Investigation of Knoevenagel Condensation in Planetary Ball Mills

      Christine F. Burmeister, Achim Stolle, Robert Schmidt, Katharina Jacob, Sandra Breitung-Faes and Arno Kwade

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300738

      Thumbnail image of graphical abstract

      Mechanochemical synthesis may offer green solutions to organic synthesis. Using the Knoevenagel reaction under solvent-free conditions in a planetary ball mill, the results are correlated with discrete element method simulations to prove the dependency of the reaction yield on stress conditions. Smaller balls were more time and energy efficient due to higher power values achieved by high stress frequencies.

    9. Mechanical Behavior of Deep-Frozen Bulk Solids at Compression

      Peter Müller, Franziska Gomolla and Jürge Tomas

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300779

      Thumbnail image of graphical abstract

      An economically and technically efficient method is needed to overcome the problems associated with frozen coal. Hard coal, iron ore, and sand samples saturated with water were deep-frozen for defined periods of time. Uniaxial compression tests were carried out to analyze the influence of the particle size and the residence time in the freezer on the material behavior.

  6. Reviews

    1. Size Reduction as Integral Element for Development and Manufacturing of Engineered Drug Particles

      Michael Juhnke and Edgar John

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300676

      Thumbnail image of graphical abstract

      A brief overview is given on drug compound and drug product characteristics impacted by drug particle size. Size reduction techniques applied after chemical synthesis and isolation processing are introduced for the engineering of drug particle size. The repercussions for the processing of highly active drug compounds are overviewed with regard to worker exposure and environmental impact.

  7. Communications

    1. Grinding of Vegetal Fibers to Micrometer Size

      Bernard J. Marin and Hélène Deleu

      Article first published online: 3 APR 2014 | DOI: 10.1002/ceat.201300640

      Thumbnail image of graphical abstract

      Wheat bran fibers are important in the food industry. Smaller fiber particle sizes could increase the extractability of its components. Therefore, different milling conditions were tested and optimal results were obtained when dry wheat bran was milled with a ball mill followed by a jet mill. Generally, finer particle size distributions could be achieved when dry milling conditions were applied.

  8. Research Articles

    1. Simulation of Multi-Stage Particle Classification in a Zigzag Apparatus

      Thomas Hagemeier, Hannes Glöckner, Christoph Roloff, Dominique Thévenin and Jürgen Tomas

      Article first published online: 19 MAR 2014 | DOI: 10.1002/ceat.201300670

      Thumbnail image of graphical abstract

      Zigzag air classifiers are superior to simple sieves for the separation of particles and are used in many industrial processes. The separation efficiency of a pilot-scale zigzag apparatus is studied using combined computational fluid dynamics simulations and discrete particle modeling. The process performance is discussed with respect to the chosen modeling approach and the operating conditions.

    2. Metathesis of Ionic Liquids: Continuous Ion Exchange by Donnan Dialysis

      P. Keil, M. Schwiertz and A. König

      Article first published online: 9 OCT 2012 | DOI: 10.1002/ceat.201200322

      Thumbnail image of graphical abstract

      A diffusion model-based approach is presented to model and optimize countercurrent Donnan dialysis. Integral transport coefficients were determined for several anions, with the objective to prepare task-specific ionic liquids (ILs) by continuous anion exchange. Anion conversions > 99 % were reached after model-based process optimization. Ultrapure IL were produced in long-term experiments for up to 130 h on stream.

VIEW

  1. 1 - 21

SEARCH

SEARCH BY CITATION