The basic material for chrome oxide green is chrome iron ore (chromite). The reduction of the alkali chromate extracted from the chromite results in chrome oxide green. Chrome oxide green (Cr2O3) is chemically inert to a large extent. It is insoluble in water, acids and alkaline solutions. The pigment is stable to heat up to approx. 1000°C. Temperatures exceeding this value lead to particle size growth and thus a colour shift.
The chromium 6 content of the chrome oxide green types distributed by Scholz is very low. Therefore, they support the low chrome (VI) content level required for cement. This prevents health problems, as they are observed in dealing with products containing chromium (VI), even before they arise.
Besides the chrome oxide types made by Lanxess, which are distributed under the brand name Colortherm Green, the product range of Scholz comprises additional types.
- Colortherm® GN
- Colortherm® GNM
- Colortherm® GX
- Chrome Oxide Green GN Z
- Bayoxide® C Gn B
- Chrome Oxide Green G 2023
- Chrome Oxide Green Granulate G 3023
Owing to the chemical and technical characteristics of chrome oxide green, these pigments are used in a wide variety of applications.
- For the colouring of concrete, plasters, paving blocks, floor coverings, asphalt, etc.
- As the colour-providing pigment in paints and lacquers, plastics As corrosion protection
- As corrosion protection
- In clinkers, mortars, tamped concrete and shotcrete mixes, for increasing the stability, and as a wetting agent of facings (foundry)
- As polishing and abrasive material
- As raw material for the production of refractory bricks.
Product properties and delivery forms of chrome oxide green pigments
The synthetically manufactured chrome oxide green pigments of the Colortherm® series and the chrome oxide green pigments of Harold Scholz are available in 3 different delivery forms, i.e. as powder, granules or as liquid pigment preparations. These high-quality colour pigments are used in many different industries.
Powder pigments are always solid substances of which the simplest form is an insoluble powder. They are predominantly used in the building industry.
Granules are spray-dried and dust-free pigments. Owing to the sophisticated manufacturing process of these granules with a very good flowability, discharging them from silos, big bags or paper bags is easy and convenient for the user. This also provides for better dosing.
Liquid colours are stabilised aqueous suspensions made of chrome oxide green powder. Due to dust-free and clean dosing, they are easy to handle for the user.