Kremer Schiefermehl hellst (40900)

Product information "Kremer slate flour light (40900)" 

40900 - 40920 slate flour 

This is a mineral consisting of numerous oxides based on Si, Al, Fe, Mg, K and Ti, 

which also contains small amounts of S, P, CO2 and Na2O. 

At the beginning of the Devonian period around 400 million years ago, a large, constantly sinking marine sedimentation basin was created from the French Atlantic coast to the Czech-Polish low mountain ranges, in which an extraordinary number of deposits and magmatic rock formations occurred due to a very flexible tectonically determined soil morphology. One of the oldest pieces of evidence of the use of Lower Carboniferous clay slate by humans are several slabs lying on top of and next to each other that were found in 1936 during excavations near Gera. They were probably used by the hunters of the Magdalenian period as slab covering for their tent buildings. The beginnings of actual slate mining go back to the 12th century, as in France and England. Since then, thin-split clay slates have been used as roofing material. Of the slate mined, only 25% can be used to make roof slate, the rest is dried, ground and fed into the various branches of the large-scale chemical industry. Today, slate powder is mainly used in anti-corrosive paints, firstly because it is optimally resistant to acids, alkalis and oxidizing media (soluble content in hydrochloric acid according to DIN 55920 - 13: 11.2%) and enhances the effect of inhibitor pigments, and secondly because the flakes are oriented parallel to the film plane and thus form a barrier layer with high tensile strength and great elasticity and also significantly improve substrate adhesion. 

The advantage is that it swells very little, so that applications in electrical insulation paints can also be considered.

Slate powder is also suitable for blending aluminum paints and for coatings with high heat and chemical resistance. 

Acid-resistant and heat-resistant putties, fillers and seals of all kinds are also made using slate powder.

In roofing felt and bitumen production, slate powder is used as a filler and weighting agent; to prevent caking and grain sizes (> 63 μ) are used for surface sprinkling.