Research On Aluminum Magnesium Dry Ramming Material Using In Induction Furnace

With the development of society,the requirements on metallurgy and casting industry are increasing.In metallurgy and casting industry,induction furnace was widely used for its high efficiency,flexibility,energy-saving,economy and other advantages.At present,the service life of relatively inexpensive induction furnaces is not long and the expensive imported induction furnace is difficult for ordinary users to bear in a long-term.The difficulties induction furnace faced had greatly limited the development of China's metallurgical and foundry industry.Therefore,developing a domestic relatively inexpensive high-quality induction furnace lining is imperative.The subject used different sizes of fused white corundum,?-A1₂O₃ powder,fused magnesia as raw materials and used dry ramming method to make aluminum magnesium dry ramming material.?1?The close particle packing experiment according to Anderson equation showed that the packing density was maximum and the particle size distribution formula designed was reasonable when the powder exponent q of Anderson equation equaled 0.25.?2?Reasonable addition amount of magnesia powder was beneficial to the performance of the sample.Adding excess amount of magnesia powder would decrease the bulk density,compression strength and enlarge the apparent porosity,linear change of the sample.Adding ?1mm magnesia had an adverse effect on the properties of the sample adding optimal amount of magnesia powder.The sample added fused magnesia had better properties than the samples with other sources of magnesium when adding the same amount.?3?Additives improved overall performance of the sample.Taking the apparent porosity,bulk density,compressive strength,the linear change and the performance of the sample at high temperature into account,the sample had a better overall performance when the addition of boron oxide was 1.5wt%,the addition of silica powder was 2wt% and the adding of ?-A1₂O₃ powder was 2wt%.?4?Firing temperature had a great effect on the physical performance of aluminum magnesium dry ramming material.When the firing temperature was below 1400 ?,the main reaction in the sample was the formation reaction of magnesia-alumina spinel by which accompanied a volume expansion,it leaded to a loose structure,a relatively poor performance of the sample,while the firing temperature was above 1400 ?,what primarily happened in the sample was sintering.?5?When the temperature was above 1030 ?,magnesia-alumina spinel could be generated by the reaction of ?-A1₂O₃ and magnesia,the activation energy of the reaction was 185.0KJ/mol,the reaction of magnesia-alumina spinel generating was controlled by three-dimensional diffusion,the mechanism function of the reaction was Jander equation G???=[1-?1-??1/3]1/2,f???= 6?1-??2/3[1-?1-??1/3]1/2.