The ball sintering method is a method in which a sintered mixture is made into a small ball to improve the gas permeability of the sintered layer, and a thick layer and a low-temperature sintering method are realized. The pellet sintering method generally requires that the pellets having a particle size of not less than 3 mm in the mixture account for more than 75% of the total amount of the mixture. The method sinter prepared cementitious columnar phase mainly acicular iron and calcium-based, high strength sinter, reducing, and less powder, large fragmentation.
As early as in the 1960s, China carried out the study of small ball sintering method. Anshan Iron and Steel developed a double-ball sintering process suitable for red ore sintering. However, due to the difficulty of the process, industrial production has not been realized. In the 1980s, Japan successfully developed a partial ball sintering method, which was put into operation on the Fushan No. 4 sintering machine in 1987. The main sintering technical indexes were significantly better than the ordinary sintering method. On the basis of domestic and foreign research, the Iron and Steel Research Institute has successfully developed a new ball sintering process, and then cooperated with the relevant units. From 1994 to 1996, the small ball sintering method was carried out in the sintering plant of Taishan Iron and Steel Company and the sintering plant of Shougang Mining Company. The success of industrial production has ended the history of China's small ball sintering process only staying in the experimental research stage, which is the result of the efforts of several generations of sintering workers in China.
At present, the small ball sintering method has been widely promoted and applied in China's iron and steel enterprises, and has achieved remarkable economic benefits.
The ball sintering method can greatly improve the yield of sintered ore, improve the quality of sintered ore, and reduce the consumption of sintering fuel. The theoretical analysis is as follows:
The output of the sintering machine can be calculated by the following formula:
Q=60KRBHV (1)
Where Q———production, t/h;
K———Production rate, %;
R——-mixed material bulk density, t/m 3 ;
B———sintering machine width, m;
H———layer height, m;
V———Sintering machine speed, m/min.
When H is expressed by the vertical sintering speed in Equation 1, then:
C=H/t
Cause: C=H/(L/V)
Then: CL=HV (2)
Where C———vertical sintering speed, m/min;
t———Sintering time, min, t=L/V;
K———Sintering machine length, m.
Substitute Equation 2 into Equation 1:
Q=60KRBCL (3)
In Formula 3, the width B and the length L of the sintering machine are invariants, and the yield K, the sintered bulk density R, and the vertical sintering speed C are variables. It can be seen that measures to improve the yield K, the loose density of the mixture R and the vertical sintering speed C are the key to the increase of the sintering machine. These three variables are analyzed separately.
(1) Mixture bulk density R
(1) The loose density R of different types of iron minerals is different. Magnetite R=4.9～6.2(t/m 3 ); hematite R=4.9～5.2(t/m 2 ); limonite R=2.7～4.3(t/m 3 ).
(2) The TFe content of similar iron minerals is different, R is also different, the TFe content is high, and R is increased. The iron grade of the iron-containing raw materials required to enter the plant is as high as possible.
(3) Under the same raw material conditions, the small spherical sinter R is larger than the ordinary sinter R, which is because the spheroidal sinter has a long peening time and a dense grain structure. The measurement indicates:
Ordinary sintered material: R = 1.5 ~ 1.9 (t / m 3 )
Small ball sinter: R = 1.7 ~ 2.0 (t / m 3 )
(2) Yield K
After the ball sintering method, the gas permeability of the sintered layer is improved, and the height of the layer can be increased. When the height of the material layer is increased, the yield K is inevitably increased. The general yield can be increased by 5% to 10%.
(3) Vertical sintering speed C
The vertical sintering speed C is the main factor affecting the output of the sintering machine. Only in the case of improving the gas permeability of the sintered layer, the vertical sintering speed can be improved. The factors related to the gas permeability of the sinter layer are as follows:
PâˆÎµ 1.58～3.0
Pâˆ1/S 0.579～2.0 (4)
Where P—the permeability index of the layer;
Ε—the porosity of the layer;
S———The specific surface area of ​​the mixture.
The above formula shows that the gas permeability of the sinter layer is proportional to the porosity of the layer and inversely proportional to the specific surface area of ​​the sinter.
The results show that the more uniform the particle size of the sintered mixture, the greater the porosity of the layer. The small particles of less than 3 mm in the pellet sintering material are greatly reduced, and therefore, the particle size is relatively uniform. Therefore, the pellet sintering method can increase the porosity of the sintered layer. In order to further increase the porosity of the layer, the ball sintering process requires the use of segregation fabric technology to increase the average diameter of the mixture, which can reduce the specific surface area S of the mixture. The sintering of the small ball increases the average diameter of the sintered material by 1 to 2 mm, and the specific surface area S of the mixture is greatly reduced.
It can be seen that the ball sintering method can increase the pore ε of the layer and reduce the specific surface area S of the mixture, thereby increasing the gas permeability index P of the sintered layer. As the permeability of the material layer is improved, the height of the material layer can be increased, thereby increasing the yield of the sintered ore, reducing the fuel consumption of the solid, reducing the FeO content in the sintered ore, and increasing the calcium ferrite mineral. Therefore, the small ball sintering method can improve the yield of sintered ore, improve the quality of sintered ore, and reduce fuel consumption.
As early as in the 1960s, China carried out the study of small ball sintering method. Anshan Iron and Steel developed a double-ball sintering process suitable for red ore sintering. However, due to the difficulty of the process, industrial production has not been realized. In the 1980s, Japan successfully developed a partial ball sintering method, which was put into operation on the Fushan No. 4 sintering machine in 1987. The main sintering technical indexes were significantly better than the ordinary sintering method. On the basis of domestic and foreign research, the Iron and Steel Research Institute has successfully developed a new ball sintering process, and then cooperated with the relevant units. From 1994 to 1996, the small ball sintering method was carried out in the sintering plant of Taishan Iron and Steel Company and the sintering plant of Shougang Mining Company. The success of industrial production has ended the history of China's small ball sintering process only staying in the experimental research stage, which is the result of the efforts of several generations of sintering workers in China.
At present, the small ball sintering method has been widely promoted and applied in China's iron and steel enterprises, and has achieved remarkable economic benefits.
The ball sintering method can greatly improve the yield of sintered ore, improve the quality of sintered ore, and reduce the consumption of sintering fuel. The theoretical analysis is as follows:
The output of the sintering machine can be calculated by the following formula:
Q=60KRBHV (1)
Where Q———production, t/h;
K———Production rate, %;
R——-mixed material bulk density, t/m 3 ;
B———sintering machine width, m;
H———layer height, m;
V———Sintering machine speed, m/min.
When H is expressed by the vertical sintering speed in Equation 1, then:
C=H/t
Cause: C=H/(L/V)
Then: CL=HV (2)
Where C———vertical sintering speed, m/min;
t———Sintering time, min, t=L/V;
K———Sintering machine length, m.
Substitute Equation 2 into Equation 1:
Q=60KRBCL (3)
In Formula 3, the width B and the length L of the sintering machine are invariants, and the yield K, the sintered bulk density R, and the vertical sintering speed C are variables. It can be seen that measures to improve the yield K, the loose density of the mixture R and the vertical sintering speed C are the key to the increase of the sintering machine. These three variables are analyzed separately.
(1) Mixture bulk density R
(1) The loose density R of different types of iron minerals is different. Magnetite R=4.9～6.2(t/m 3 ); hematite R=4.9～5.2(t/m 2 ); limonite R=2.7～4.3(t/m 3 ).
(2) The TFe content of similar iron minerals is different, R is also different, the TFe content is high, and R is increased. The iron grade of the iron-containing raw materials required to enter the plant is as high as possible.
(3) Under the same raw material conditions, the small spherical sinter R is larger than the ordinary sinter R, which is because the spheroidal sinter has a long peening time and a dense grain structure. The measurement indicates:
Ordinary sintered material: R = 1.5 ~ 1.9 (t / m 3 )
Small ball sinter: R = 1.7 ~ 2.0 (t / m 3 )
(2) Yield K
After the ball sintering method, the gas permeability of the sintered layer is improved, and the height of the layer can be increased. When the height of the material layer is increased, the yield K is inevitably increased. The general yield can be increased by 5% to 10%.
(3) Vertical sintering speed C
The vertical sintering speed C is the main factor affecting the output of the sintering machine. Only in the case of improving the gas permeability of the sintered layer, the vertical sintering speed can be improved. The factors related to the gas permeability of the sinter layer are as follows:
PâˆÎµ 1.58～3.0
Pâˆ1/S 0.579～2.0 (4)
Where P—the permeability index of the layer;
Ε—the porosity of the layer;
S———The specific surface area of ​​the mixture.
The above formula shows that the gas permeability of the sinter layer is proportional to the porosity of the layer and inversely proportional to the specific surface area of ​​the sinter.
The results show that the more uniform the particle size of the sintered mixture, the greater the porosity of the layer. The small particles of less than 3 mm in the pellet sintering material are greatly reduced, and therefore, the particle size is relatively uniform. Therefore, the pellet sintering method can increase the porosity of the sintered layer. In order to further increase the porosity of the layer, the ball sintering process requires the use of segregation fabric technology to increase the average diameter of the mixture, which can reduce the specific surface area S of the mixture. The sintering of the small ball increases the average diameter of the sintered material by 1 to 2 mm, and the specific surface area S of the mixture is greatly reduced.
It can be seen that the ball sintering method can increase the pore ε of the layer and reduce the specific surface area S of the mixture, thereby increasing the gas permeability index P of the sintered layer. As the permeability of the material layer is improved, the height of the material layer can be increased, thereby increasing the yield of the sintered ore, reducing the fuel consumption of the solid, reducing the FeO content in the sintered ore, and increasing the calcium ferrite mineral. Therefore, the small ball sintering method can improve the yield of sintered ore, improve the quality of sintered ore, and reduce fuel consumption.
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