Study reveals cause of increased dusting from slag handling

After desulphurization of hot metal slag is formed which, after separation from the hot metal, is deposited on special slag handling sites at SSAB. At the slag heap, this handling generates clouds of dust, which are classified in three categories, of which class 3 causes the greatest problem. 

Problem with increased dust clouds

Minimizing this dust generation is important for improving the immediate environment. During the summer months of 2013 the proportion of class-3 dust clouds increased to 12.5 %, as opposed to 2.9 % during the same period in 2010. 

In a study conducted by Swerim and SSAB the cause of this increase was investigated. The rates of production in 2010 and 2013 were relatively similar. 

Minimizing the clouds

By analysing process data, Swerim was able to determine that more slag was generated during the desulphurization process, resulting in more trips to the slag heap. 

As a result of the increased amount of slag, new disposal sites had to be created. Before the slag is removed from these sites, it must be water-cooled. More slag demands a greater volume of water. 

Water affect the size of cloud

The study revealed that class-3 dust clouds are affected by the volume of cooling water. Based on the results of the study, SSAB has decided to conduct trials with an aim to improve the immediate environment and minimizing the proportion of class-3 dust clouds.