Search - Number 10 - SINTERING OF MAGNESIUM-ALUMINIUM SPINEL - AN INERT MATRIX FOR ISOLATION OF HIGHLY ACTIVE WASTE

SINTERING OF MAGNESIUM-ALUMINIUM SPINEL - AN INERT MATRIX FOR ISOLATION OF HIGHLY ACTIVE WASTE
Cover not present SINTERING OF MAGNESIUM-ALUMINIUM SPINEL - AN INERT MATRIX FOR ISOLATION OF HIGHLY ACTIVE WASTE
Category: Number 10
Publication: 10
Summary

Sintering of magnesium-aluminium spinel specimens on air and in vacuum in the interval of tem-peratures 700   1700  С was investigated. The material is offered to be used as an inert matrix for insulation of radioactive waste. Nanosized powders obtained using a method of cojoint reversed precipitation from a mixture of solutions of magnesium and aluminium nitrate salts. Sintering takes place intensively in the inter-val temperatures 1100 - 1500 ?С and less active - at 1500 - 1700 ?С. Activation energy of sintering equals 37.9   0.6 and 9.4   0.6 кJ/mol accordingly. Magnesium-aluminium spinel with relative density of 94.7 % was obtained by heat treatment at temperature 1700  С within 1 hour. Using the methods of X-ray phase analysis and infrared spectroscopy it is determined, that the obtained material has no other phases except for magnesium-aluminium spinel. The structure has grains 4 - 8 ?m and small rounded 0.8 - 1.2 ?m and major irregular 2.0 - 3.5 ?m pores. Activation energy of grain growth equals 83.1  1.5 кJ/mol.