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-10 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-10 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.
Air entraining additives for mortar
n response to the new requirements demanded by the cement industry, PROQUICESA has developed a line of additives that promotes the inclusion of air in the cement mortar in the form of microbubbles homogenously distributed.
These additives, included in the range of PROQUICESA’s ADITOR® AES additives, increase workability and durability cement based on a greater resistance to freeze-thaw cycles and a greater fluency of the mortar. Additives comprising this range allow the occlusion of a quantity of air in the mortar which can range between 4-12% depending on customer needs and raw materials characteristics.
These features make these ADITOR® AES additives especially useful for paving materials or other situation where they will be exposed to changing climatic conditions, specially cold weather, and in situations that more fluid mixtures are preferred.
As result of our full specialization in the field of additives for the cement industry and of our permanent contact with the cement manufacturers, PROQUICESA has other series of additives that make up this line of specialty products, focused on changing cement setting times, called ADITOR® J.
Grinding aids modifiers of the setting times, also marked by the highest quality standards of quality like the rest of our products, have arisen as result of research projects started at the request of certain customers to meet targets of various kinds: provide specific qualities their cements, save certain technical conditions, etc.