Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for reducing the expansion rate of pellets

A technology of pelletizing and expansion rate, which is applied in the field of iron pellets for blast furnace ironmaking, can solve the problem that the blast furnace cannot be used in a large proportion, and achieve the effect of reducing the expansion rate and meeting the requirements of the blast furnace

Active Publication Date: 2020-03-27
SHANXI TAIGANG STAINLESS STEEL CO LTD
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0018] The above examples show that the expansion rate of alkaline pellets produced by conventional technology is 31.3%, which is much higher than the standard of less than 20% required by large blast furnaces, so blast furnaces cannot be used in large proportions

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0061] In this embodiment, the FeO content of the iron ore powder used in the production of pellets is reduced from 10.4% in the example of the background technology to 6.2%, and the particle size of the flux limestone powder is changed from the original conventional "less than 0.074mm" to 84%. "Adjusted to "less than 0.044mm is 94.3%". At the same time, the hood temperature of the grate preheating stage II in the grate-rotary kiln roasting equipment was increased from 1130°C to 1145°C, and the time for the pellets to pass through the preheating stage II was extended from 4.6 minutes to 6.8 minutes.

[0062] In detail, in this embodiment, the method for reducing the pellet expansion rate may include the following steps:

[0063] (1) Ingredients

[0064] Iron ore powder, limestone powder and bentonite are weighed and proportioned according to the following parts by weight, and the specific proportioning is:

[0065] Limestone powder 67 parts,

[0066] Iron ore powder 918 par...

Embodiment 2

[0076] In this embodiment, the FeO content of the iron ore powder used in the production of pellets is reduced from 10.4% in the example of the background technology to 5.5%, and the particle size of the flux limestone powder is changed from the original conventional "less than 0.074mm" to 84%. "Adjusted to "less than 0.044mm is 94.3%". At the same time, the temperature of the fume hood in the grate preheating stage II was increased from 1130°C to 1145°C, and the time for the pellets to pass through the preheating stage II was 6.8 minutes.

[0077] In detail, in this embodiment, the method for reducing the pellet expansion rate may include the following steps:

[0078] (1) Ingredients

[0079] Iron ore powder, limestone powder and bentonite are weighed and proportioned according to the following parts by weight, and the specific proportioning is:

[0080] Limestone powder 67 parts,

[0081] Iron ore powder 918 parts,

[0082] 12 parts of bentonite,

[0083] Among them, th...

Embodiment 3

[0091] In this embodiment, the FeO content of the iron ore powder used in the production of pellets is reduced to 4.7% from 10.4% in the example described in the background technology, and the particle size of the flux limestone powder is changed from the original conventional "less than 0.074mm" to 84%. "Adjusted to "less than 0.044mm is 94.3%". At the same time, the temperature of the fume hood in the grate preheating stage II was increased from 1130°C to 1145°C, and the time for the pellets to pass through the preheating stage II was 6.8 minutes.

[0092] In detail, in this embodiment, the method for reducing the pellet expansion rate may include the following steps:

[0093] (1) Ingredients

[0094] Iron ore powder, limestone powder and bentonite are weighed and proportioned according to the following parts by weight, and the specific proportioning is:

[0095] Limestone powder 67 parts,

[0096] Iron ore powder 918 parts,

[0097] 12 parts of bentonite,

[0098] Amon...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
particle sizeaaaaaaaaaa
particle sizeaaaaaaaaaa
particle sizeaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method for reducing the expansion rate of pellets. The method comprises steps of formulation, uniformly mixing and pelletizing, and calcination. In the formulation step, theiron ore powder, limestone powder and bentonite are formulated according to the following weight percentage which is 60 -90 parts of limestone flour, 850 -950 parts of iron ore powder and 8 -20 partsof bentonite, wherein the content of FeO in the iron ore powder is in a range of 3 -5%, and the proportion of the limestone powder particles of particle size of less than 0.044mm is 93% or above. in the uniformly mixing and pelletizing step, the iron ore powder, the limestone powder and the bentonite are uniformly mixed and then pelletized to produce pellets, the water content of the pellets is 8%to 10%, and the average particle size of the pellets is 9 -15 mm. In the calcination step, the pellets are arranged on a grate - rotary kiln, a piece of calcination equipment, to be calcinated to obtain finished pellets, wherein the temperature of the smoke cover of the preheating ii section of the grate - rotary kiln is larger than 1140 degree Celsius, and the preheating period is larger than 6. 5min. According to the method, the expansion rate of the finished pellets can be remarkably reduced to be less than 20%, and the requirements of a blast furnace can be met.

Description

technical field [0001] The invention relates to the technical field of iron material pellets for blast furnace ironmaking, in particular to a method for reducing the expansion rate of pellets. Background technique [0002] Acid pellets are important iron-containing raw materials for blast furnaces, but their high-temperature metallurgical properties, poor basicity sintered ore, especially low reduction degree, low softening start temperature, and wide softening temperature range seriously deteriorate the high-temperature zone of blast furnaces. air permeability. When using, if the operation system of developing the edge is adopted, if the acid pellet rolls to the edge of the furnace wall, because of the low temperature at the beginning of soft melting and dripping, it may cause melting and damage to the slag skin of the furnace wall, which is not conducive to the furnace lining protection, will negatively affect the life of blast furnace refractories. [0003] Therefore, i...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C22B1/24C22B1/20C22B1/216C22B1/26
CPCC22B1/20C22B1/216C22B1/2406C22B1/26
Inventor 范建军史永林李昊堃蔡湄夏贺淑珍张华
Owner SHANXI TAIGANG STAINLESS STEEL CO LTD