The Impacts of Grinding Ball Size Distribution on Energy Consumption, Product Size and Media Wear within the Dry Stirred Mill

Öz

Nowadays, it is desired to use water resources more efficiently due to environmental factors. In this context, the importance of dry stirred mills is increasing day by day. In ball mills, grinding performance can be increased by using media with different sizes and choosing the appropriate grinding media size distribution. It is thought that a similar approach can be applied for dry-stirred mills. Thus, it is predicted that there may be effects on grinding performance and product quality. Although there has been an increasing amount of research on dry stirred mills lately, a missing point is the discussion of the effect of grinding media size distribution. Within the scope of the study, the effect of ball size distribution - a variable that directly affects the mill’s performance - on the grinding performance of the vertical dry stirred mill was investigated by batch grinding tests. For this purpose, the bi-modal and tri-modal compositions of the media sizes selected using the material size-ball size ratio values developed in the literature were mixed in different ratios for the vertical stirred mill. The data obtained from the tests performed at different stirrer speeds for calcite, clinker, and copper ores were evaluated in terms of energy, shape of the size distribution, and the obtained size reduction ratios. In addition, the effects of using different sized media distributions on media wear are discussed. It is thought that the findings obtained from the study will be beneficial on the dry stirred mill technology, which is expected to become increasingly widespread.

Anahtar Kelimeler

• Grinding
• fine grinding
• stirred mill
• optimization

Kuru Karıştırmalı Değirmende Bilya Boyu Dağılımının Enerji, Ürün Tane Boyu ve Bilya Aşınması Üzerindeki Etkilerinin Araştırılması

Öz

Kuru karıştırmalı değirmenler üzerine yapılan çalışmalar son yıllarda hız kazanmıştır. Birçok değişken üzerinde araştırmalar yapılmış ancak değirmenlerin temel değişkeni olan bilya dağılımının etkileri detaylı olarak incelenmemiştir. Geleneksel bilyalı değirmenlerde, farklı çapta bilyalar kullanılıp, uygun dağılımın seçimi ile öğütme performansı arttırılabilmektedir. Benzer yaklaşımın kuru karıştırmalı değirmenler için de uygulanabileceği böylelikle, öğütme performansı ve ürün kalitesi üzerinde olumlu etkilerinin olabileceği öngörülmektedir. Bu çalışma kapsamında değirmen performansını doğrudan etkileyen bir değişken olan bilya boyu dağılımının, dik kuru karıştırmalı değirmenin öğütme performansı üzerine etkisi, kesikli öğütme testleri ile incelenmiştir. Bu amaçla, literatürde geliştirilen malzeme boyu ve bilya boyu oranı değerleri kullanılarak seçilen bilya boylarının, dik karıştırmalı değirmen için, ikili ve üçlü bileşimleri farklı oranlarda karıştırılmıştır. Kalsit, klinker ve bakır cevheri için farklı karıştırma hızlarında yapılan testler sonucunda elde edilen veriler, enerji, boyut dağılımının şekli ve boyut indirgeme oranları yönlerinden değerlendirilmiştir. Ayrıca, farklı boyutlara sahip bilya dağılımının kullanılmasının, bilya aşınmasına etkileri tartışılmıştır. Çalışmadan elde edilen bulguların, giderek yaygınlaşması beklenen kuru karıştırmalı değirmen teknolojisi üzerinde faydalı olacağı düşünülmektedir.

Anahtar Kelimeler

• Öğütme
• ince öğütme
• karıştırmalı değirmen
• optimizasyon

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