Powder multistage suspension preheating kiln outside calcium oxide calcining method

Abstract

The invention discloses a powder multistage suspension preheating kiln outside calcium oxide calcining method. The powder multistage suspension preheating kiln outside calcium oxide calcining method comprises following steps: 1, limestone powder is introduced into a multistage suspension preheating kiln for preheating to 800 to 900 DEG C; 2, the pre-heated material is introduced into a decomposition furnace, and calcining is carried out for 25 to 35s at 900 to 1100 DEG C; 3, the calcined material is conveyed back into a rotary kiln, and is subjected to calcining for 25 to 35min at 1100 to 1300DEG C, and is cooled to obtain calcium oxide. According to the method, the step in the prior art that block limestone is subjected to direct calcining is changed into the above steps that limestone is crushed into powder, and suspension preheating, decomposition furnace calcining decomposition, and rotary kiln calcining slaking are adopted to prepare powdery calcium oxide, the single line production capacity is 5 to 10 times higher than that of the conventional method, and energy saving and environment protection are realized.

Description

technical field [0001] The invention relates to a calcining method for calcium oxide, in particular to a method for decomposing and calcining calcium oxide outside a powder multistage suspension preheating kiln. Background technique [0002] There are mainly two methods for producing calcium oxide (lime) at present. The first method is to use a vertical kiln to fire, and the second method is to use a single-stage preheating rotary kiln to fire. [0003] The vertical kiln is for calcination of large limestone with a particle size of 100mm-300mm. During the calcination process, it needs to be matched with suitable fuel, and it enters the kiln simultaneously for combustion. In this process, large limestone is required to achieve the effect of ventilation and combustion. The combustion speed is slow, the efficiency is low, the energy consumption is high, the output is low, the quality is poor, and it is necessary to increase environmental protection desulfurization and denitrifi...

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Problems solved by technology

[0003] The vertical kiln is for calcination of large limestone with a particle size of 100mm-300mm. During the calcination process, it needs to be matched with suitable fuel, and it enters the kiln simultaneously for combustion. In this process, large limestone is required to achieve the effect of ventilation and combustion. Slow burning speed, low efficiency, high energy consumption, low output, poor quality, and need to increase environmental protection desulfurization and denitrification equipment, resulting in high production costs

[0004] The single-stage preheating rotary kiln is for calcination of limestone with a particle size of 40mm-80mm. The material slowly enters the kiln head of the rotary kiln and injects fuel for combustion. The waste heat generated during the combustion process of the rotary kiln enters the single-stage preheater at the kiln tail. Inside, the material has a certain preheating effect, but it absorbs heat slowly, and the material particles are relatively large, resulting in relatively poor combustion effect, relatively long calcination and decomposition time, poor ventilation effect, etc., low output, high energy consumption, poor quality, and It is also necessary to increase environmental protection desulfurization and denitrification equipment

[0005] These two traditional processes are to calcinate block limestones of different sizes into block lime at high temperature, and then undergo grinding, hydration and other processes, and further process them into lime powder, lime paste (slaked lime) and other materials. Traditional processing methods Low production capacity, the current single machine production capacity is 100 to 800 tons / day, and the energy consumption is high, the energy consumption is 3350kJ / kg (200 kg standard coal), and the power consumption is 50 degrees

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