Kozlu taşkömürünün koklaşma özelliklerine Oltu linyiti ilavesinin etkisi

Öz

Ülkemizde kok üretimi için kullanılan taşkömürü rezervleri oldukça sınırlıdır. Ancak koklaşamayan linyit rezervleri ise oldukça yüksektir. Linyitlerin taş kömürlerine ilave edilerek kok üretiminde kullanılabilmesi için bu karışımların koklaşabilme özelliklerinin tespit edilmesi gerekmektedir. Bu çalışmada Erzurum Oltu linyiti ve Zonguldak Kozlu taşkömürü ve bu kömürlerin belirli oranlarda hazırlanan karışımları kullanılmıştır. Ham kömür ve kömür karışımlarının koklaşma kalitesini belirleyen nem içeriği, kül, uçucu madde, petrografik analiz, serbest şişme indeksi, Gray-King kok testi, dilatasyon ve plastisite (akışkanlık) gibi çeşitli parametreler incelenmiştir. Oltu kömüründe maseral bileşiminin %75 oranında hüminitten oluşması bu kömürün düşük ranklı karakterini, Kozlu kömürünün %65 vitrinit içeriği yüksek ranklı ve koklaşabilir karakterini göstermektedir. Mikrolitotip bileşimleri de bu durumu desteklemektedir. Kömürlerin ve karışımlarının serbest şişme indeksi testinde, %100 Oltu linyitinin hiç yapışma göstermediği, %100 Kozlu kömürünün ise iyi bir koklaşma özelliğini yansıtan 6 FSI değerine sahip olduğu belirlenmiştir. Gray-King kok testinde, Oltu linyiti tek başına bir kok tipi üretmezken, %100 Kozlu kömürü ve %20 Oltu-%80 Kozlu karışımı G tipi bir kok üretimi sağlamıştır. Akışkanlık testleri, Oltu linyitinin tek başına hiçbir plastisite veya akışkan davranış göstermediğini, Kozlu taş kömürünün ise 87 °C'lik geniş bir plastik aralık ve 980 DDPM'lik (dakikada kadran bölümü) maksimum akışkanlık gösterdiğini ortaya koymaktadır. Genleşme testlerinde, Oltu linyiti herhangi bir genleşme olmadan yumuşama ve büzülme davranışı göstermiş, Kozlu kömürü ise yumuşama ve büzülmenin yanında %+118'lik önemli bir genleşme oranı göstermiştir.

Anahtar Kelimeler

• Koklaşma
• karışım
• koklaşma parametreleri

Effect of Oltu lignite addition on coking properties of Kozlu hard coal

Öz

In our country, hard coal reserves used for coke production are quite limited. However, non-coking lignite reserves are quite high. In order for lignites to be added to hard coals and used in coke production, the coking properties of these blends should be determined. In this study, Erzurum Oltu lignite and Zonguldak Kozlu hard coal and blends of these coals prepared at certain ratios were used. Various parameters such as moisture content, ash, volatile matter, petrographic analysis, free swelling index, Gray-King coke test, dilatation and plasticity (fluidity) which determine the coking quality of raw coal and coal blends were investigated. The 75% huminite content of the maceral composition in the Oltu coal indicates its low-ranking character, while the 65% vitrinite content in the Kozlu coal indicates its high-ranking and coking character. Microlithotype compositions also support this situation. In the free swelling index test of the coals and blends, it was determined that 100% Oltu lignite did not show any adhesion and 100% Kozlu coal had a FSI value of 6, which reflects a good coking property. In the Gray-King coke test, Oltu lignite alone did not produce a coke type, while 100% Kozlu coal and 20% Oltu-80% Kozlu coal blend produced a G type coke. Fluidity tests revealed that Oltu lignite alone showed no plasticity or fluid behaviour, while Kozlu coal showed a wide plastic range of 
87 °C and a maximum fluidity of 980 DDPM (Dial Division per minute). In expansion tests, Oltu lignite showed softening and shrinkage behaviour without any expansion, while Kozlu coal showed softening and shrinkage as well as a significant expansion rate of +118%.
 

Anahtar Kelimeler

• Coking
• blend
• coking parameters

Kaynakça

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