Volume No. 10 Issue No.: 4 Page No.: 593-601 April-June 2016

 

MICRO-STRUCTURED IRON(III) HYDROXIDE AGGLOMERATES WITH HIGH POROSITY AS ADSORBENT

 

Ay P.*, Glaser C., Logsch F.1, Narra S.2, Gemende B., Gerbeth A., Riedel T.,
Pausch N.3, Leiker M., Bäde B. and Heiduschke R.4

1. Department of Mineral Processing, Faculty of Environmental Sciences and Process Engineering Brandenburg University of Technology Cottbus-Senftenberg (GERMANY)
2. Technical Environment and Climate Protection, University of Applied Sciences, Luebeck (GERMANY)
3. University of Applied Sciences, Zwickau (GERMANY)
4. P.U.S. Produktions- und Umweltservice GmbH, Lauta (GERMANY)

 

Received on : January 10, 2016

 

ABSTRACT

 

This study focusses on the production of micro-structured agglomerates with high porosity from iron(III)-hydroxide-containing materials as adsorbent. A fractal like structure of the agglomerates is to be created through a two-stage agglomeration process. This is necessary to achieve porous structures and to increase the adsorption capacity. Various materials were used for the agglomeration experiments : filter cake (dry matter content 23 to 27 wt.-%) and FerroSorp®DGμ, a product which is already being used commercially for various applications in water cleaning. These materials have different characteristics in the natural state such as dry matter content and particle size distribution. Further, the purity of the iron(III)-hydroxidecontaining materials with respect to the amounts of organic and inorganic materials is of particular importance during application. 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®DG? (d90 < 30 ?m) was agglomerated jointly with the aforementioned filter cake in an Eirich intensive mixer (particle size range 125 ?m < d90 < 500 ?m). The second agglomeration step after drying was carried out in a pelletisation plate 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 6 h, 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.

 

Keywords : Microstructured agglomerate, Iron (III)-hydroxide-containing material, Adsorption capacity, Adsorbent for water cleaning, Ferrous catalysts

 

 

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