Öncü Madencilik was founded in Eskişehir in 1994. Regular extraction began in 2006, and in 2016 the company concentrated entirely on mining.
Today we work our own licensed deposits in the Eskişehir basin. The sedimentary magnesite we produce has been used for many years as a body raw material by more than twenty of the largest ceramic tile manufacturers in Türkiye. Our first shipment to Europe took place in 2022, supplied in volume to one of the largest ceramic producers in Spain and used successfully in production.
Our product is raw, uncalcined sedimentary magnesite (MgCO3). Its silicate-bearing structure makes the material behave differently in a ceramic body from refractory-grade magnesite, and that difference is precisely what makes it suited to tile bodies.
In a tile body, magnesite works as a secondary flux alongside feldspar. It lowers the peak firing temperature, raises mechanical strength and reduces water absorption. Because it acts strongly, it is used in small proportions, and the effect on gas consumption per fired tonne is direct. Dosage is set by the producer's own formulation.
Published work on magnesium-bearing fluxes reports reductions in sintering peak of the order of 50 °C at optimum dosage.
Increases in green, dry and fired bending strength are reported for magnesite additions in wall and floor tile bodies.
Denser vitrification at the same firing cycle, with firing shrinkage kept within standard once dosage is controlled.
| Oxide | Mass % |
|---|---|
| MgO | 43.59 |
| SiO2 | 4.97 |
| CaO | 1.42 |
| Al2O3 | 1.17 |
| Fe2O3 | 0.35 |
| Loss on ignition | 48.11 |
| Property | Value |
|---|---|
| Main phase (XRD) | Magnesite |
| Secondary phase(s) | Enstatite-type pyroxene |
| Free quartz | not detected |
| Moisture, 110 °C | seasonal |
| Form supplied | raw, uncalcined |
| HS code | 2519.10 |
Buyers of ceramic-grade magnesite watch two impurities above all: free quartz, which causes pinholing in glaze, and dolomite, which brings unwanted CaO into the body.
X-ray diffraction identifies the secondary phase not as free quartz but as a magnesium silicate carrying trace calcium, an enstatite-type pyroxene. At 1.42% CaO the dolomite content is minimal.
All figures are taken from reports issued by SAM, Seramik Araştırma Merkezi A.Ş., the ceramic research centre affiliated with Eskişehir Technical University. A certificate of analysis accompanies each shipment.
Download technical profile (PDF)
| Licensed area | 860 ha |
| Estimated reserve | 2,200,000 t |
| Method | Open pit |
A sedimentary magnesite laid down in a lacustrine setting: interbedded with clay horizons, soft in texture and pale in colour. Worked without drilling or blasting and shipped raw. Odunpazarı district.
| Licensed area | 850 ha |
| Estimated reserve | 2,150,000 t |
| Plant | Crush, screen, sort |
The site where magnesite is produced, processed through jaw crushers, screens, magnetic separators and a washing drum. Beylikova district.
Our material is used as a body raw material by more than twenty of the largest ceramic tile manufacturers in Türkiye. Türkiye is the world's fourth-largest ceramic tile producer, and these plants run the same body formulations, on the same equipment, as their European counterparts.
Our material has been supplied in volume to one of the largest ceramic producers in Spain and used successfully in production.
Until now our material has reached export markets through intermediaries. From 2026 export sales are handled in-house, which means the buyer deals directly with the company that owns the deposit: technical questions answered by the producer, quality certified at source, and no trading margin in between.
Samples are supplied on request, accompanied by full laboratory analysis. Tell us the requirement of your body formulation and we will respond with specification and terms.
info@oncumining.com
+31 625 11 47 74 · call
+90 532 457 55 44 · WhatsApp
+90 222 220 26 52
+90 541 262 62 07
+90 542 263 49 90
İstiklal Mh. Reşadiye Cad. No: 8
Yelkovan İş Merkezi, Kat 2 / No 112
Eskişehir, Türkiye
Operations in Odunpazarı district. Loading port: Gemlik.