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ABSTRACT
It is known that the medium-grade and low-grade iron ores before the direct use in metallurgical furnaces are almost always concentrated. For ore-grain release all run-of-mine ore is crushed and milled. The result of such operations is a finely ground concentrates, which are then subjected to clotting. Among the known methods of clotting of the wide-spread high-temperature methods - sintering and pelletizing followed by baking raw pellets. During these processes, there is a partial removal of detrimental impurities (sulfur, phosphorus, etc.). However, for loose rich iron ore with low content of detrimental impurities may be preferable to conduct the "cold" briquetting using small amounts of binding substances (such as molasses or carboxymethyl cellulose water solution). This method allows obtaining a lumpy product of high quality without additional costs for the sintering or baking of raw products. The article sums up the results of research of physical and mechanical properties of briquettes, concentrated from loose high-grade iron ores with different binding substances. Testing of samples for uniaxial compression, falling, shatter and wear were conducted, including drawing of strength characteristics. The test results show that produced briquettes meet the requirements (to use it in the blast-furnace burden).
Keywords: clotting, loose high-grade iron ores, binding substance, physical and mechanical
INTRODUCTION
It is known, iron ore raw materials base of Russia consists mainly of medium-grade and low-grade iron ores, which are almost always subject to the concentration and subsequent clotting.
Among the known methods of clotting the most wide-spread are high-temperature methods such as sintering and pelletizing followed by baking raw pellets.
But for some types of iron ores briquetting is the preferred method of clotting [1 - 4].
However, in our country there is a certain amount of deposits of high-grade iron ores (with iron content 50% or more), which is preferable to clotting by "cold" briquetting [5 - 8].
This method allows to:
* using ores with a grain size of 0-10 mm without concentration and grinding while pelletizing needs ores with a grain size of 0.07-0.05 mm;
* producing hard grains without extra baking, which is carried out...