High Temperature Strength Of Sinter

With the rising of the coal rate, the coke rate has been greatly reduced presently and the penetrable quality of the charging column was worsened. In this case, more attention was paid to the high-temperature strength of the sinter on the lumpy zone in blast furnace. At present, however, the method of checkout cannot well and truly image the practice and meet the requirement of iron production. Misdata may result in distractor in sintering process. In this thesis, tests on the compressive strength of sinter using a high temperature compressive testing machine with adjustable atmosphere were completed. The main results are as follows:(1) The compressive strength of sinter decreased gradually with the rising of the temperature and it was discovered that the downtrend of the compressive strength was placid under 600℃and evident above 700℃.(2) The compressive strength of sinter after reduction was fluctuant because it had a concave between 500℃and 600℃, but it decreased gradually after it had a peak value at about 700℃.(3) The compressive strength of sinter had a complex relation to its reduction degree. For example, it declined rapidly in the area of reduction degree between 5% and 10% but increased slowly in that between 10% and 20%. However, it tobogganed once more when the reduction degree was between 20% and 30%.(4) At higher temperature, the change of compressive strength of sinter was more intensive with the change of the reduction degree. At 850℃, it was about 80% of the original value when the reduction degree was about 10% and when the reduction degree was 25%, it was about 40% of the original value. At a higher temperature of 900℃, it decreased rapidly from about 60% to circa 90% when the reduction degree turns from 8% to about 30%.(5) The compressive strength of sinter after reduction with higher pore ratio was lower and had a beeline relationship with the pore ratio. The related expressions at different temperatures were given in this work.The damage mechanism of sinter in blast furnace was discussed in this thesis. Based on that, advices on quality evaluation and process optimizing in sinter production were given. Moreover, a suit of more simple and applicable equipment for sintering test in laboratory was opened out.