Facilitating cement grinding in vertical mills
Summary: In the cement industry, the necessity of continuous improvements in the grinding process and the related cost reduction has promoted the proliferation of vertical cement mills worldwide. These particular mills present a vast series of advantages compared to traditional, horizontal ball mills. Nevertheless, for reasons which derive principally from a different ventilation, “traditional” grinding aids do not seem to be able to provide the same performance enhancements which are achieved in horizontal ball mills. The present article describes a novel class of grinding aids developed especially for vertical mills. Furthermore, an innovative dosage technology which substantially increases the performance of these products is also described. The combined effect of these two distinct aspects constitutes an efficient, new technical approach for cement grinding in vertical mills.
Mainly due to lower specific energy consumption (measured in kWh/t of material produced) and higher production (t/h) values, vertical cement mills are slowly, but steadily, outnumbering “traditional”, horizontal ball mills. The immediate advantages of such mills can be easily summed up in the following key points:
– vertical cement mills are able to reach production values which are significantly higher than the ones achievable with traditional ball mills. As the latter are able to reach an indicative maximum of 180 –200 t/h, vertical mills reach up to 300 t/h.
– lower energy...
