Tureckie surowce skaleniowe w krajowej produkcji p ytek ceramicznych

Feldspar raw materials belong to such raw materials for which demand has risen in Poland in the last years to a largest extent. The reason of it is the expansion of domestic branch of ceramic tiles. Larger and larger demand of the Polish industry of ceramic tiles for feldspar raw materials is covered among others in greater and greater extent by import from Turkey. Feldspar raw materials in that country are mainly obtained from albite-rich rocks which occur in the west part of the country in Menderes Massif particularly in its south fragment (Submassif ine). Their exploitation and proccessing are carried out by many companies from which KALTUN, ESAN ECZACIBASI, INE AKMADEN, KALEMADEN and ERMAD are of the greatest importance in the Polish market. The raw material of the highest quality (Na2O + K2O > 10%, Fe2O3 ≈ 0.02%, TiO2 ≈ 0.02-0.03%) is obtained as a result of benefication of primary rocks by flotation. The main compounds - apart from quartz - of studied samples analized by means of microscopic method are feldspars represented first of all by albite. This mineral occurs in two varieties. First of them - which strongly dominates - is so called chessboard albite. This variety is formed as a result of albitization of feldspars of various types. On the other hand, typical, multitwinned crystals of this mineral are observed significantly rarer. Albite most often contains 5-10 mol.% of anorthite molecule. Sporadically minor and/or trace minerals (e.g. titanite, rutile, micas) occur in samples studied. They are the carriers of colouring oxides (Fe2O3, TiO2) presence of which is outstandingly undesirable, especially in raw materials for the production of ceramic tiles of the highest quality such as gres porcellanato. The characteristic feature of the Turkish feldspar raw materials is occurrence of minor or trace amount of TiO2 in domination compared to Fe2O3 which mostly is more common colouring oxide in feldspar raw materials. It is connected with sporadic occurrence of such titanium minerals as titanite CaTi[O|SiO4] and rutile TiO2. However, in the majority of investigated samples the presence of these carriers of colouring oxides was not stated which confirms the opinion about high quality of feldspar raw materials of Turkish production.