The American Foundry Society’s Environmental, Health and Safety Division recently presented ME Elecmetal with the division’s 2020 Safety Innovation & Insight Award in the category of health. These awards honor innovative practices, programs, and projects that make plants safer, healthier or more ergonomically friendly places to work.

ME Elecmetal was presented this award in recognition of its creativity in controlling silica exposure while applying furnace refractory patch at both of its North American foundries.

The number one source of exposure is the siliceous fireclay refractory patch material used for the lining of the EAF melting furnaces. ME Elecmetal trialed alumina-based refractory, which did not hold up as well as the silica-based material. The company spent a lot of time on optimizing and standardizing the water patch mix utilized while patching, in addition to lots of training and awareness of proper patch application. While patch machine operation optimization did have a positive effect, it was not enough and was unreliable.

At both of our facilities ME Elecmetal built custom mobile “patch” hoods to fit on top of the electric arc furnaces to be able to utilize the side draft hood that normally ventilates the arc furnace while melting. These hoods were designed to be able to fit on furnaces with various orientations and not require the need to have more than one at each facility. This hood is to be used when applying the siliceous fireclay refractory material during furnace preparation and patching operations in between heats. The project in Duluth cost roughly $1,000,000, and the project in Tempe was only $100,000. This is due to the decision to add a separate 50,000 CFM dust collector in Duluth for the patching operation (it also added some general ventilation when patching is not happening). The melting dust collector controls in Duluth, MN are already susceptible to freezing during winter months and the dust bridging due to humidity and freezing that adding more moisture during patching would have added additional issues. The Tempe, AZ facility decided to use the mobile patch hood with their existing melt collectors.

Due to the need for using a separate dust collector for patching operations in Duluth, several controls were needed to control which collector ventilates the side draft hoods. Control dampers actuate based on the operation to direct flow to the different collectors as needed. The patch dust collector provides some general ventilation at the south end of the facility where slag handling takes place when patching is not happening.

In addition to the mobile hood, the company also added ventilation at the patch machines. A backdraft slotted hood for the bag pierce and feeding of the patch machines as well as a hood round the transition from the bag pierce hopper to the pressure vessel (patch transporter).

After these changes and sorting out some other challenges, the company’s most recent 2020 exposure data is as follows:

— Duluth (ug/m3): 47, 47, 63, 31, 41, 74, 23, 30, 45
— Tempe (ug/m3): 47, 52, 21, 21

Through additional testing at both facilities — taking pumps on and off during patching activities — it has been shown that the task of patching is what has the potential of exposing the operators over the PEL. So, in addition to drastically improving the overall exposure in the melt shop, ME Elecmetal can limit the restricted areas to being around the furnaces and patch machines only while patching.

“When we first engineered and endeavored this whole concept back then, I knew it would be a big feat,” said Scott Schudalla, Vice President of Manufacturing for ME Elecmetal. “Now, looking back at what we do in Melt Operations to make this concept tick, it’s just part of everyday life. Cycle times haven’t crashed, compliance is met at a tighter standard, and most importantly, we are operating in a manner that shows our employees we will invest in their equipment and safety to make a better workplace”