Smelting Daily Question 10.25 (English Version)

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This post was last edited by FILTRATION-MAN on 2011-10-25 at 15:40. 1. Please hide your replies; editing after posting is ineffective! Delete directly without hiding! 2. Hiding method: http://bbs.hcbbs.com/thread-492556-1-1.html 3. 10 points or 1 charm for a completely correct answer, 1 point for a completely wrong answer, and 5 points for an answer that is somewhere in between. 　　One word in one blank: In the history of iron and steelmaking technology, the first process is the direct reduction process. The blast furnace takes the ______ of the direct reduction process, which is a great improvement in metallurgical technology. As the iron and steel industry develops, coke, on which blast furnaces have relied for over 200 years, is becoming increasingly expensive, and the supply of suitable coking coals is decreasing. The direct reduction process was reintroduced at the end of the 18th century. _______, technologies that produce iron by reducing iron ore below the melting point of iron are generally classified as direct reduction processes, with the resulting products being known as direct reduced iron (DRI). The answer to this question can be found in the next question. The answer to the previous question: Refractories used in furnaces that operate at high temperatures clearly require higher overall operating temperatures. Refractories with a higher alumina content can be ______ to enable the furnace dome temperature to be raised to 1315°C; further increases in temperature require the use of special silica-based refractories resistant to creep. Refractories in such furnaces must also withstand thermal cycling as well as the ______ of alkali and iron oxides. The ______ of refractories in these furnaces can be quite long, but it depends heavily on the degree of contamination of the furnace by impurities present in the gases, which may contain large amounts of iron or alkali. These impurities can shorten the lifespan of the refractories