Cr(VI) Reduction - C-ADD Mapei (2024)

MA.P.E./Cr 07 is a micro-granulated chromate reducing agent for cement and ready mix mortars.
MA.P.E./Cr 07 is based on the brand new “controlled release” technology, developed by MAPEI and patent pending.
MA.P.E./Cr 07 is composed of antimony trioxide encapsulated and micro-granulated in a special soluble polymer. When dispersed in cement, during mortar or concrete preparation, micro-granules are dissolved, thus releasing the reducing agent.
MA.P.E./Cr 07 allows the use of antimony trioxide without the health risks associated to the inhalation of fine dusts.

MA.P.E./Cr 07 can be dosed directly in the cement mill, or during cement bagging or blending using a suitable powder dosing system. Generally speaking we suggest a dosage around 15 g/t for each ppm of Cr(VI) in the cement.
Optimised dosages are obtained when MA.P.E./Cr 07 is perfectly dispersed in cement: the better the dispersion, the lower the dosage. For this reason, particular care has to be taken in proper dispersion of micro-granules in cement.
Performances of hexavalent chromium reduction are similar to other antimony-based products manufactured and commercialized by Mapei: under normal cement storage conditions, the reducing action shall remain unchanged for at least six months.

The usage precautions are related to the potential risk of inhalation of fine antimony trioxide particles: it has to be pointed out that the encapsulation in soluble polymer and the micro-granulation completely eliminates the fine fraction, thus eliminating the aforementioned risk.
For further information, please refer to the Safety Data Sheet and to the MA.P.E./Cr 07 safety dossier, available on request.

N.B. – Although the technical details and recommendations contained in this product report correspond to the best of our knowledge and experience, all the above information must, in every case, be taken as merely indicative and subject to confirmation after long-term practical applications: for this reason, anyone who intends to use the product must ensure beforehand that it is suitable for the envisaged application: in every case, the user alone is fully responsible for any consequences deriving from the use of the product.

MA.P.E./Cr 05 is a chromate reducing agent, based on accurately selected raw materials in order to guarantee constant quality and high performance.
MA.P.E./Cr 05 is a liquid additive which has to be added to the mill during the cement grinding process. It ensures the production of cements without Cr(VI), according to the European directive 2003/53/EC.

MA.P.E./Cr 05 guarantees, besides advantages coming from the use of a liquid product, an efficient and stable reduction of soluble chromates in cement and hydraulic binders. It is an absolutely innovative liquid product: a patented MAPEI technology based on antimony compounds. During cement hydration the reducing agent acts on soluble chromates, converting Cr(VI) into Cr(III).

MA.P.E./Cr 05 can be successfully employed in cement and hydraulic binders and in general wherever it is necessary to reduce Cr(VI).
The additive must be used only during grinding, added onto the clinker conveyor belt or directly in the first chamber.
In any case it should be added as close as possible to the mill entrance, avoiding long and complicated distances which could cause a loss of additive before entering the mill.
MA.P.E./Cr 05 is particularly suitable in case of high soluble chromates content and when a long lasting reduction of chromates is required: under normal cement storage conditions, the reducing action shall remain unchanged for at least six months.

Please refer to the appropriate safety data sheets.

The dosage depends on the Cr(VI) content in the cement and the grinding system. Generally speaking we suggest a dosage between 50 and 55 g/t for each ppm of Cr(VI) in the cement. The additive dosage, in any case, has to be optimised through a reliable industrial trial, preferably with the help of our Technical Assistance Group.

MA.P.E./Cr 05 is available in drums, IBC tanks and in bulk tank trucks (full truck loads).

MA.P.E./Cr 05 is a stable dispersion of antimony compounds in water. All necessary precautions must be taken so that all the storage conditions potentially affecting the stability of the suspension are carefully controlled.
Avoid temperatures above 40°C.
MA.P.E./Cr 05 has a neutral/slightly alkaline pH: 8.0±1.5. Any dilution and contamination with other substances must strictly be avoided, with particular reference to other products for hexavalent chromium reduction that are normally very aggressive, corrosive and characterized by a very acid pH.
MA.P.E./Cr 05 is supplied in IBC, the stability is at least eight (8) months if stored in the original packaging, closed firmly and stored away from direct sunlight and heat sources. Once the IBC has been opened, the product should be consumed as soon as possible as stability may be reduced.
If MA.P.E./Cr 05 is supplied in bulk tank truck, stability is four (4) months if stored properly. It is recommended to use suitable storage systems (preferably in HDPE).

MA.P.E./Cr 05 can be dosed by means of membrane or peristaltic pumps.

The use of a liquid dispersion like MA.P.E./Cr 05 is safe, because any release of antimony dust is completely eliminated.
For further information, please refer to the Safety Data Sheet and to the MA.P.E./Cr 05 safety dossier, available on request.
PRODUCT FOR PROFESSIONAL USE ONLY.

N.B. – Although the technical details and recommendations contained in this product report correspond to the best of our knowledge and experience, all the above information must, in every case, be taken as merely indicative and subject to confirmation after long-term practical applications: for this reason, anyone who intends to use the product must ensure beforehand that it is suitable for the envisaged application: in every case, the user alone is fully responsible for any consequences deriving from the use of the product.