Investigation of the usage of fly ash containing a high amount of sulfate as a clinker replacement material

Year 2023, Volume: 29 Issue: 5, 507 - 512, 31.10.2023

Murat Saydan , Furkan Türk , Ülkü Sultan Keskin , Hilal Say

Abstract

Tons of fly ash are released every year due to the coal burned in thermal power plants that meet 80% of Türkiye's electrical energy needs. Especially considering the low-quality lignite reserves in Türkiye, the recycling rate of the high sulfate fly ash is relatively low. In concrete production, the use of ash containing high SO3 is not allowed due to the limitation of SO3 ratios of fly ash by regulations. Herein, the usability of fly ash, which has a high sulfate content due to the low-quality lignite reserves in Türkiye, and is therefore wholly waste, as a clinker replacement material was investigated. Fly ash, which has been used as a clinker replacement material, was obtained from Afşin Elbistan thermal power plant. Binders were obtained by grinding together the high sulfate fly ash, clinker and gypsum at different rates. The setting times of the mixtures in the fresh cement paste were determined, and the compressive strengths of the hardened samples were examined. As a result of the study, it was concluded that although the high sulfate fly ash extended the setting time by approximately 29% compared to the reference specimen, it increased the 28-day compressive strength of the hardened specimens up to 14%.

Keywords

Waste, High sulphate fly ash, Clinker, Compressive strength, Cement production

Yüksek oranda sülfat içeren uçucu küllerin klinker ikame malzemesi olarak kullanılabilirliğinin incelenmesi

Abstract

Türkiye’nin elektrik enerjisi ihtiyacının %80’ini karşılayan termik santrallerde yakılan kömürlerden dolayı her yıl tonlarca uçucu kül açığa çıkmaktadır. Özellikle ülkemizdeki düşük kaliteli linyit rezervleri düşünüldüğünde, açığa çıkan yüksek sülfat içeriğine sahip uçucu küllerin geri dönüşüm oranı oldukça düşüktür. İnşaat sektöründe ise yönetmelikler tarafından uçucu küllerin SO3 oranlarının sınırlandırılması sebebiyle yüksek SO3 içeren küllerin kullanımlarına izin verilmemektedir. Bu çalışmada, ülkemizdeki düşük kaliteli linyit rezervleri sebebiyle yüksek sülfat içeriğine sahip olan, dolayısıyla tamamıyla atık durumda bulunan uçucu küllerin, klinker ikame malzemesi olarak kullanılabilirliği araştırılmıştır. Klinker ikame malzemesi olarak kullanılacak olan ve yüksek oranda sülfat içeren uçucu kül Afşin Elbistan termik santralinden temin edilmiştir. Yüksek oranda sülfat içeren uçucu kül, klinker ve alçı ile farklı oranlarda birlikte öğütülerek karışımlar elde edilmiştir. Karışımların taze halde priz süreleri tayin edilmiş, sertleşmiş numunelerin ise basınç dayanımları incelenmiştir. Çalışma sonucunda, yüksek sülfat içeren uçucu külün priz bitiş sürelerini referans numuneye göre yaklaşık %29 uzatmasına rağmen, 28 günlük basınç dayanımlarını %14’e kadar artırdıkları tespit edilmiştir.

Keywords

Atık, Yüksek sülfatli uçucu Küller, Klinker, Basınç dayanımı, Çimento üretimi

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