I’m Mirco Venetz and today I get to tell you how diverse and exciting a day at the steel mill can be for an apprentice. Starting at our electric arc furnace where scrap is melted, then moving on to secondary steelmaking, all the way to the casting pit. Currently I’m working at the (what we call it) “new steel mill” with the ladle furnaces. Here’s what my day there looks like:
Start of my day
My day starts at 6.30 am at the time clock – just a bit after the start of the regular shift time. Then I go to the locker room to put on my safety gear. After I’ve changed, I walk straight to the new steel mill to the ladle furnaces where I say hello to my workmates and familiarize myself with the cast program and today’s list. I see that our batch is just being melted in the furnace. Even before the batch is tapped, I make sure the workplace is clean and that everything that is expected to be needed is in place. Next, I check whether the ladle furnace electrodes are long enough or whether they need to be shortened or expanded – in this case, an additional electrode piece is screwed on so that the melt can be heated. Everything’s ready now and the melt is about to be tapped – together with the plant operator I walk to the furnace to calculate the first alloys and to start alloying.
Control and analysis
Now we return to the ladle furnaces where, as soon as the batch arrives, the actual work begins for us. The batch is heated and alloyed to the target analysis. We keep checking the slag and correct it, if necessary, with lime, alumina and aluminum grit. If the analysis is ready for further treatment, we start vacuum degassing. This is done to remove gases that would harm the steel and to increase the degree of purity. After vacuum treatment the molten steel is prepared for the casting process. That means: setting the final alloys and, depending on the quality, rinsing for approx. 20 minutes. This is done in order to achieve exactly the degree of purity that we guarantee. In the end, a final sample is drawn which is used for the test report.
The bell rings
Then we ring the bell so that everyone in the pit knows that casting is about to begin. Today’s rather quiet, so I also go to the pit and help with casting. The trolley’s ready and in the meantime the ingot molds have been delivered, flooded with argon and the right casting powder has been hung in at the correct height. The ladle is lifted into the trolley, the ladle slide gate is connected, and as soon as the spout is in the correct position the ladle slide gate is opened – first a couple hundred kilos of steel into the box before the filling of the ingot molds can start. The ingot molds start to fill up more and more. The ingots are done, now put the exothermic welding powder on top, and as soon as that’s burned the covering powder goes on top. We call this “top treatment”. I take another look at the finished ingot molds which now have to stand for a few hours to solidify. For today, my work is done.
Instructive and exciting
Right before I take a shower and get changed, I stop by the office to do some small tasks, mostly evaluations of production data for all kinds of analyses. The clock strikes 2.30 pm, I go to the locker room and clock out for the day. On my way to the train station, I think back at my workday and realize that it was yet another instructive and exciting day.