Whole-body type external-heating muffle type rotary kiln

Abstract

The invention belongs to the field of metallurgical equipment, and in particular relates to a whole-body type external-heating muffle type rotary kiln. A whole-body type continuous external heating muffle type coal-based rotary kiln device with a preheating section and a high-temperature section is adopted, the continuous stabilization of the temperature in a high-temperature area is realized, and a strict requirement on a reduction condition of reduced iron is met. By adopting a muffle-type heating mode, a reduction atmosphere in the rotary kiln is very full, the volatile gas is totally recycled, and the afterheat is fully utilized, so that the required reduction temperature of reduced materials can be greatly reduced, the reduction speed is greatly increased, the energy consumption is greatly reduced, and the carbon emission is reduced; by using non-caking coals with high granularity and high quality as reducing coals, the device is suitable for various iron raw materials with high grade, low grade and varieties, the reduction process is flexible, and the device has many advantages. According to a single production line of the device, the annual reduction treatment ore quantity can reach the maximum scale of 1,800,000-2,100,000 tons.

Description

technical field [0001] The invention belongs to the field of metallurgical equipment, and in particular relates to a flame-chambered rotary kiln with external heating. Background technique [0002] China is a big country of steel. Today, steel output has exceeded 800 million tons. Although my country's iron ore resources are widely distributed, the distribution of low-poor, fine and refractory iron ore resources accounts for more than 96%. So far, they have not been well developed and utilized, resulting in idle and waste of resources. On the contrary, steel mills still need to import a large amount of iron ore every year. For high-grade iron ore, import dependence accounts for more than 55% of the total iron ore consumption of steel mills. [0003] China's iron and steel industry used to vigorously develop blast furnace ironmaking, but reduced iron technology is relatively lagging behind. my country's annual output of reduced iron is about 500,000 tons, accounting for less ...

AI Technical Summary

Problems solved by technology

[0009] For the above-mentioned reduced iron methods, the investment scale of each production line is tens of millions to hundreds of millions, which limits the investment of reduced iron investors into this field

[0010] In the existing external heating flame-insulated coal-based rotary kiln method, due to the support ring and support wheel in the middle of the kiln, the high temperature section of the kiln cannot be heated for a long distance, and the heating furnace can only leave the support ring and support wheel support part , forming a segmented external heating flame-insulated rotary kiln

Therefore, the scale of the kiln is small, the reduction temperature is low, the temperature in the high-temperature zone is discontinuous and unstable, and the whole body heating of the rotary kiln cannot be realized, and the reduction drum of the rotary kiln is single-cylinder, and combined with segmental heating, it cannot adapt to reducing iron. Requirements for the continuity and stability of reduction temperature can only be used on a small scale in industries with less processing capacity such as chemical industry and non-ferrous precious metals, which limits its development in the field of reduced iron

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