Calcite and dolomite aggregate used in industrial applications may appear to be a simple raw material at first glance, yet in reality it is a critical component that directly determines final product quality across very different sectors: glass, plastics, paint, paper, and construction chemicals. A batch selected with the wrong parameters can lead to color deviation on the production line, loss of strength, and even product recall costs. At Alpay Doğaltaş, as we source aggregate to industrial users from Turkey's various calcite and dolomite deposits, primarily the Saraylar area of Marmara Island, we evaluate the decisive technical criteria for each sector in detail.
The first and most decisive parameter in industrial aggregate selection is the calcium carbonate ratio. The CaCO3 value directly affects the purity of the raw material and therefore the performance of the final product. Batches to be used in glass production are expected to have a CaCO3 ratio of 98.5 percent and above, while values of 97 percent and above are acceptable for filler use. The higher this ratio, the lower the non-reactive impurity content of the raw material. The white dolomite and calcite aggregates we supply are documented with a CaCO3 analysis for each batch after being classified at partner processing facilities, before reaching the end user.
The granulometric curve stands out as the second critical parameter. In industrial applications it is not the grain size itself but the grain size distribution, that is, the shape of the curve, that is decisive. For micronized products used as fillers in the paint and plastics sectors, fine-grained homogeneous batches are preferred at the raw material source. The paper sector requires specific d50 values for filler and coating applications. In the construction chemicals sector, a narrow band granulometric distribution is preferred because it affects mixture rheology. The consistency of the granulometric curve in the batches we supply is ensured by sieve systems and air classifiers operated at partner processing facilities.
Whiteness is the determining acceptance parameter, particularly in premium paint, paper, and plastics applications. Measured as the whiteness value, this property is inversely proportional to the iron oxide (Fe2O3) and other coloring component content of the calcite aggregate. Deposits with an Fe2O3 ratio below 0.05 percent are suitable for sectors that demand a white product. The white dolomite we source from the Saraylar area of Marmara Island is a preferred source for these sensitive applications thanks to its low iron content and high whiteness. The whiteness value is measured for each batch with a spectrophotometer and reported, so no color inconsistency occurs on the production line.
