Sintering process

Abstract

The invention discloses a sintering process, which comprises the following steps of: adding a sintering raw material into a rotary kiln from the tail end of the rotary kiln; spraying fuel from the head end of the rotary kiln to sinter the sintering raw material; discharging clinker sintered from the head end of the rotary kiln; collecting flue gas in the rotary kiln from the tail end of the rotary kiln; dedusting the collected flue gas; and returning a part of kiln dust separated from the flue gas to the rotary kiln. The sintering process can effectively eliminate ring formation in the rotary kiln, saves deslagging operation, and has high safety and low cost.

Description

technical field [0001] The invention relates to a sintering process, in particular to a sintering process in alumina production. Background technique [0002] Alumina is the main raw material for electrolytic aluminum smelting. Most of the current alumina production uses bauxite as raw material, the main production method is the Bayer method, and a few use the sintering method, Bayer-sintering series method, etc. [0003] In alumina production using the sintering method or the Bayer-sintering tandem method, raw meal or Bayer red mud needs to be sintered, traditionally using sintering equipment with a rotary kiln. [0004] Rotary kiln is the main component of sintering equipment. The rotary kiln can be divided into four zones according to the sequence of sintering materials moving in the furnace and processing, namely drying zone, decomposition zone, firing zone and cooling zone. [0005] During the sintering operation, due to the high temperature in the rotary kiln, espec...

AI Technical Summary

Problems solved by technology

[0005] During the sintering operation, due to the high temperature in the rotary kiln, especially in the sintering zone, the high-temperature sintered material is easily bonded to the inner wall of the rotary kiln, that is, ring formation of the sintered material on the inner wall of the rotary kiln occurs. Especially in the part where the sintering zone is adjacent to the decomposition zone, ring formation is more likely to occur, thus affecting the normal progress of sintering and requiring frequent maintenance

When ringing is serious, even sintering cannot be carried out

In addition, when the ring formation reaches a certain level, the ring formation sintering material falls off from the kiln wall, forming a large egg-shaped block, which is easy to damage the sintering equipment during the downward process, such as the kiln body of the rotary kiln and / or cooling devices for cooling the fired clinker and presenting a safety hazard

[0006] For this reason, the traditional sintering process usually requires an air cannon or a slag breaker to break the oversized fired clinker block in the rotary kiln, which increases the complexity of the process and leads to an increase in production costs

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