Proquicesa

The Cr(VI) existing in the cement is a sensitizing agent which can originate skin diseases, like contact dermatitis, in people who handle cement pastes, mortars and concretes, causing different levels of injury. In order to avoid this phenomenon, Directive 2003 / 53 / CE has imposed to European cement manufacturers the limit of Cr(VI) content in their cements of 2 ppm, as maximum.

Since the presence of the species Cr(VI) in the cement essentially derives from the oxidation of the element chromium existing in certain materials used for its manufacture, the solution to the problem happens to add to cement an external chemical agent able to reduce the Cr(VI) – soluble- to Cr(III) - insoluble -, which is not absorbed by the skin.

After years of R&D in this field, PROQUICESA have formulated an additive reducer of Cr(VI) in cements, whose characteristics and benefits turn to it in one of the most advantageous and profitable options of the market nowadays.

ADITOR® Cr-770 is a low viscosity liquid product, fully suitable to be supplied in bulk, that can be dosed in the entrance of the mill by employing a simple pumping system, not needing special equipment for its unloading, transfer, and storage.

It is a stable dissolution which allows large periods of storage without lose of properties. It does not settle, for what the 100% of the product can be used, and not generate residues. And it has a wide expiry, in terms of duration of its reducer effect in the cement (~ 4 months).

Its handling is fully safe, hygienic and careful with the environment, since it is not a corrosive and/or abrasive product (classified Xi-Irritant), and it is possible to be dosed on the feeding belt of the mill, without damaging the faying surfaces.

ADITOR® Cr-770 is effective on all type of cements, under low dosages: between 150 and 180 ppm of additive per each ppm of Cr(VI) to be reduced, depending on the characteristics of the cement.

 

Related publications:

  Technical Report: "Nuevo Aditivo Reductor de Cr(VI) en Cementos. Desarrollo y Experiencias Industriales

Published in Cemento y Hormigón (Apr 09)