EP 2 077 979 B2

Additives and methods for reducing hexavalent chromium in cement

(22) 26.10.2007

(43) 15.07.2009

(45)12.09.2012/27.04.2016

(73) Mapei S.p.A., 20158 Milano (IT)

(57) This invention relates to a method for reducing hexavalent chromium in common cement. This method consists in the use of selected antimony(III) compounds directly added to cement before, during or after grinding. The efficacy of the method relies on the fact that the antimony(III) is a strong reducing agent in alkaline solution and can effectively reduce chromium(VI) to less toxic and less soluble chromium(III). The antimony(III) compounds are in liquid form or in form of suspension of solid particles in a liquid carrier. …

(84) AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR; AL BA HR MK RS

x

Related articles:

Issue 1/2022 MAPEI SPA

Hexavalent chromium in cement, 15 years later

Since January 2005, following the implementation of directive 2003/53/EC [1], cement or cement-based preparations placed on the European market must not release, when mixed with water, more than 2...

more
Issue 2015 Drymix MAPEI

Encapsulation and controlled ­release of Cr(VI) reducing agent: ­application in ready-mix mortars

1 Introduction The manufacturing process of Portland cement is standardized and widely described in several publications [1]. Raw materials (usually limestone and clays, with some aluminium and iron)...

more
Issue 12/2012

The leaching of antimony from concrete

Although already present in Portland cements (basically as a consequence of the use of secondary fuels [1]) antimony recently gained importance due to the fact that it had been identified as one of...

more
Issue 1-2/2019 HRP20181461 (T1)

Portland cement additives consisting of a reducing agent embedded in a polymer matrix

(22) 12.09.2018 (43) 02.11.2018 (57) Summary of the corresponding patent EP2662346 (A1): A method is described for reducing hexavalent chromium in common cements and cement based materials comprising...

more
Issue 1/2024 WO 2023/198871 A1

Method for manufacturing cement clinker using stainless steel slag

(22) 14.04.2023 (43) 19.10.2023 (57) In the method for manufacturing cement clinker raw materials which include at least one stainless steel slag material are calcined and burned to produce the cement...

more