SELEE® wins the 2017 Corporate Technical Achievement Award for the development of an aluminosilicate-based ceramic foam filter for molten iron and aluminum filtration.
Many foundries today use ceramic foam to filter molten iron and aluminum when high quality castings are desired. Metal castings are found everywhere, from parts in your automobile like engine blocks, brake drums, and crankshafts, to the pan on your stove. SELEE® alone has sold almost 1 billion iron foundry ceramic foam filters since we introduced the first one in the 1980s. Its composition was based on silicon carbide, largely because the filtration of molten iron demands excellent thermal shock resistance as well as high strength and refractoriness from the filter. In practice, molten iron at over 1400°C is poured directly into the filter at ambient temperature. It cannot break, creep or spall during the filtration step. Thus the high thermal conductivity, low thermal expansion and refractoriness properties of silicon carbide are quite useful in producing filters capable of meeting these stringent demands. Over the last three decades, several companies have entered the marketplace with competitive ceramic foam filters, and most of these were also designed using silicon carbide as the main component. Ultimately, silicon carbide became the material of choice for the iron filtration market.
A couple major problems developed in recent years with respect to this product that led SELEE® to take action. The production of silicon carbide powder is a costly, environmentally-unfriendly process with a significant portion supplied from China. In mid-2008, Chinese governmental export policies and local supply/demand dynamics resulted in dramatic price increases and declining availability. Since that time, conditions have eased somewhat, but remain volatile and unpredictable. This event mobilized SELEE® to launch a new product development program in order to protect its customers from price increases and filter shortages, and challenge the paradigm of silicon carbide in iron foundry filters.
A significant amount of time and resources were devoted to the program, and in January 2010 SELEE® introduced “SELEE IC™”, an aluminosilicate-based filter that is completely free of silicon carbide, yet capable of meeting the thermal shock and refractoriness challenges of iron foundry filtration applications. The attributes of aluminosilicate combined with a newly engineered ceramic formulation enabled the creation of a product equal in performance with an improved supply chain. All ceramic materials for this product are sourced from the United States, which eliminates the impact of ocean freight costs, foreign currency fluctuations, and political risks. Patents have been issued in Mexico, Canada, US, India, China, Europe, and Russia. Since January 2010, SELEE® has sold over 200 million filters with the new formulation, providing customers with stable pricing and filter availability. The use of SELEE IC™ is continuing to grow with over 90% of its customer base converted. To date, SELEE® is the only ceramic foam producer that has reformulated its traditional silicon carbide ceramic foam filter in order to achieve the benefits described above. We are excited to offer yet another new product in the arena of molten metal filtration.