Abstract
In order to find out the construction materials for the process of reactions (3) and (4) of the magnesium-iodine thermochemical cycle the corrosion tests of ceramics (alumina, mullite, periclase, graphite, glass linings, etc.) and some jointing mortars were carried out for test durations up to 1000 hours and at temperatures up to 700°C in the atmosphere of a HI-I2-H2O mixed gas. The atmosphere was prepared without hydrogen, since hydrogen has little effect on the corrosion of ceramics. The corrosion resistance has been evaluated by observing the change in appearance, weight, and strength after the test. The test results were as follows: (1) The oxide materials (alumina, mullite, etc.) and graphites showed a good corrosion resistance at 500°C and 700°C. (2) Aluminum phosphate type jointing mortar was favorable. On the other hand, sodium silicate type mortar showed remarkable weight gain and decrease of bending strength accompanied by deposition of sodium iodide, and could not be assessable as candidate materials. (3) The pyroceram type glass lining specimens did not show any changes in its appearance and in weight at temperature range between 200°C and 500°C, while standard type were damaged.
