Anti wetting additives for aluminosilicate refractories in molten aluminum contact applications

<p>"Aluminosilicate based refractories are widely used in furnace installations for melting aluminum because they are inexpensive, readily available and generally exhibit the properties desired from a refractory material. However, they face severe corrosion and degradation issues due to the extremely reducing nature of molten aluminum alloys. Isothermal static cup testing is widely used as a tool to evaluate the performance of refractories against penetration by molten aluminum alloys. Various testing methods were reviewed and an upgraded static cup test was recommended. Commercially available aluminosilicate refractories were tested using this method and their results were studied in order to understand the corrosion process.</p> <p>Barium sulfate, which is widely used as an anti-wetting additive to improve refractory performance by limiting physical contact between molten metal and the refractory, has proved ineffective at temperatures above 1000⁰C. A literature review suggested that barium sulfate formed barium celsian at high temperatures and that the celsian was responsible for the non-wetting effect. Wetting angle measurements of molten AL 5083 on synthetic celsian discs revealed that barium celsian and strontium celsian were both not wetted by molten aluminum. Static cup tests were performed on aluminosilicate refractories containing barium carbonate and strontium carbonate. These additives led to the in-situ formation of celsian phases within the refractory matrix that led to improved corrosion resistance at 1300⁰C. Phase analysis revealed that celsian formation suppressed the formation of mullite within refractories, thereby reducing penetration"--Abstract, page iv.</p>

Name thesis:degree_name

Ph. D. in Ceramic Engineering

Grantor

Missouri University of Science and Technology

Year dc:date.available

2016

Author dc:creator

• Shukla, Devdutt Pramod

• Ceramic Materials

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/1778

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-2780