Microbeam has recently constructed a slag sticking apparatus (pictured below) to better address ash bonding to steel/ash surfaces. We use the apparatus in determining the adhesive strength of slag on steel surfaces as a function of steel temperature, steel type, steel surface corrosion/oxidation/sulfidation, and slag type.
We perform tests with the sticking apparatus by melting a 1/8″ diameter cylindrical ash pellet (mounted on a wire), which is then dropped onto a heated steel substrate. The pellet adheres to the heated steel surface and the adhesion force of the slag droplet to the steel surface is measured using a pushrod. A load cell measures the force of the pushrod to shear the slag from the steel.
An example of sticking test results of slag on an unoxidized and oxidized alloy appears below. The results show a higher adhesive strength for slag on the oxidized surface. Results are used for selection of steels and use of coating.