Method for roasting ultralow-carbon lime in rotary kiln and lime product produced by same

A technology of rotary kiln and limestone, which is applied in the field of ultra-low carbon lime roasting in rotary kiln and lime products produced by it, can solve problems such as inability to meet quality requirements, and achieve the effects of low production cost, good moisture resistance and long shelf life

Active Publication Date: 2012-12-19
TAIYUAN IRON & STEEL GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The carbon content of active lime produced by traditional technology is ≥0.5%, which cannot meet the requirements of high-grade silicon steel, pipeline steel, ultra-low

Method used

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  • Method for roasting ultralow-carbon lime in rotary kiln and lime product produced by same
  • Method for roasting ultralow-carbon lime in rotary kiln and lime product produced by same

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0046] Example 1

[0047] Prepare 20-40mm limestone before the experiment, with a particle size exceeding the upper and lower limit and not exceeding 3%, the raw material S content is 0.02wt%, and the CaO content is 52wt%.

[0048] The main parameters of rotary kiln calcination are controlled according to the following standards: speed 0.73 rpm, calcination temperature 1010℃, kiln head temperature 650℃, secondary air volume 53000Nm 3 / Hour, the coal injection rate is 6800 kg / hour, and the fuel injection rate is 6L / min.

[0049] After being calcined for 1.5 hours, it was cooled to 100°C and crushed by a PC300×400mm hammer crusher to obtain lime with a particle size of 0-15mm. The lime was sieved through a linear vibrating screen with an upper layer of 12mm and a lower layer of 5mm to obtain a particle size of 2- 12mm lime is passivated by adding calcium chloride to obtain a lime product.

Example Embodiment

[0050] Example 2

[0051] Prepare 20-40mm limestone before the experiment, with a particle size exceeding the upper and lower limit and not exceeding 3%, the raw material S content is 0.02wt%, and the CaO content is 52wt%.

[0052] The main parameters of rotary kiln calcination are controlled according to the following standards: rotation speed 0.8 revolutions per minute, calcination temperature 1050 ℃, kiln head temperature 920 ℃, secondary air volume 55000Nm 3 / Hour, coal injection rate is 7200 kg / hour, fuel injection rate is 10L / min.

[0053] After calcination for 2.5 hours, it was cooled to 150°C and crushed with a PC300×400mm hammer crusher to obtain lime with a particle size of 0-15mm. The lime was sieved through a linear vibrating sieve with an upper layer of 12mm and a lower layer of 5mm to obtain a particle size of 2- 12mm lime is passivated by adding calcium chloride to obtain a lime product.

Example Embodiment

[0054] Example 3

[0055] Prepare 20-40mm limestone before the experiment, with a particle size exceeding the upper and lower limit and not exceeding 3%, the raw material S content is 0.02wt%, and the CaO content is 52wt%.

[0056] The main parameters of rotary kiln calcination are controlled in accordance with the following standards: speed 0.76 rpm, calcination temperature 1030°C, kiln head temperature 785°C, secondary air volume 54000Nm3 / h, coal volume 7000 kg / h, fuel injection volume 8L / min.

[0057] After calcination for 2 hours, it was cooled to 120°C and crushed with a PC300×400mm hammer crusher to obtain lime with a particle size of 0-15mm. The lime was sieved through a linear vibrating sieve with an upper layer of 12mm and a lower layer of 5mm to obtain a particle size of 2- 12mm lime is passivated by adding calcium chloride to obtain a lime product.

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Abstract

The invention relates to a method for roasting ultralow-carbon lime in a rotary kiln and a lime product produced by the same. The method comprises the following steps: sufficiently roasting limestone at the high temperature of 1010-1050 DEG C for 1.5-2.5 hours under the conditions of coal quantity 6800-7200 kg/hour and fuel charge 6-10 L/hour, cooling, crushing, screening, and adding a surface modifier for passivation, thereby obtaining the lime product. The low-carbon lime has the advantages of favorable moisture resistance, long storage period, low production cost, high purity and high activity, and satisfies the RH furnace refinement decarburization/denitrification technique of high-designation silicon steel, pipeline steel and ultralow-carbon steel.

Description

technical field [0001] The invention relates to a method for roasting lime in a rotary kiln and a lime product produced therefrom. Background technique [0002] At present, domestic large-scale production of active lime production processes mainly include shaft kilns, rotary kilns, and mechanical kilns, and coal powder, coal gas, and natural gas are mainly used as fuels. The carbon content of active lime produced by traditional technology is ≥0.5%, which cannot meet the requirements of high-grade silicon steel, pipeline steel, ultra-low carbon steel and lime powder used in RH decarbonization and desulfurization. The carbon content of active lime is less than 0.2%, S≤0.025% , CaO ≥ 90% quality requirements. [0003] Therefore, there is an urgent need to develop a new method to prepare the above-mentioned lime meeting the carbon content requirement. Contents of the invention [0004] In order to be able to produce lime with a carbon content lower than 0.2%, the present inv...

Claims

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Application Information

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IPC IPC(8): C04B2/10
Inventor 程立衡旭文田林凯苏延德耿德昌蔡书云王华冠康彦萍
Owner TAIYUAN IRON & STEEL GROUP
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