Sintering agglomeration method of limonite

Abstract

The invention discloses a sintering agglomeration method of limonite. The sintering agglomeration method comprises the following steps: adding the limonite which accounts for 50-65% of an iron-containing material; the addition amount of the solid fuel is 5.2-8.7% of that of the sintered material; the solid fuel is divided into two parts, one part is used during batching, and the other part is used during granulation; during sintering, the thickness of a material layer is 850-1100 mm; the ignition temperature is 1000 to 1100 DEG C; the negative pressure is 3-7 kpa; the ignition time is 2-5 minutes; the air draft negative pressure is 14 to 18 kpa; according to the method, the solid fuels with different granularities are added in the burdening and pelletizing processes respectively, and the content of the limonite is increased by controlling the water content of the sintered material, the ore return amount, the alkalinity and the component content of the sintered ore, the thickness of the sintered material layer and the ignition process parameters and the air draft negative pressure in the sintering process.

Description

Technical Field

[0001] The invention belongs to the technical field of ironmaking, and in particular relates to a sintering agglomeration method for limonite. Background Art

[0002] The price of high-quality imported ore is high and the production capacity is declining year by year. The large-scale addition of high-quality imported ore does not meet the actual needs of my country's steel production. Therefore, adding a high proportion of cheap imported limonite has become one of the effective measures to reduce the cost of sintering ore blending. However, limonite itself has a low assimilation temperature, and the pores will be surrounded by liquid phase if they are not dense during sintering. The loose body provides a large number of gas transmission channels, which reduces the mineralization time of sintering ore and deteriorates the quality indicators of sintering. The existing technology always increases the ratio of flux and fuel and screens the limonite that meets the particle size requirements on a large scale, so the existing technology has no industrial production value.

[0003] Patent CN201910658015.X discloses a high-proportion limonite sintering method, which effectively overcomes the thin-walled large air pores generated during the sintering process by increasing the flux and fuel ratio, and improves the yield of the sintered ore. However, the additional solid fuel and flux will increase the sintering energy consumption. Patent CN202010553269.8 discloses a graded circulation sintering method for limonite, which requires screening and grading the limonite, and mixing and layering with a variety of iron-containing and other materials in a specific manner after processing different particle sizes separately. At the same time, strictly control the mixture parameters, the ratio of each material, the sintering method and related process parameters, etc., to optimize the sintering process, but the operation process is too cumbersome and industrial production is difficult. Summary of the invention

[0004] The purpose of the present invention is to provide a sintering agglomeration method for limonite, so as to increase the utilization ratio of limonite in sintering.

[0005] The present invention adopts the following technical scheme: a sintering agglomeration method of limonite, comprising:

[0006] The amount of limonite added is 50-65% of the iron-containing material; the amount of solid fuel added is 5.2-8.7% of the sintering material;

[0007] Divide the solid fuel into two parts, one for batching and the other for pelleting;

[0008] During sintering, the thickness of the material layer is 850-1100mm; the ignition temperature is 1000-1100℃; the negative pressure is 3-7kpa; the ignition time is 2-5min; and the exhaust negative pressure is 14-18kpa.

[0009] Furthermore, when batching, 52-60% of the total solid fuel is added; and when batching, the proportion of solid fuel with a particle size of 2-5 mm is more than 75%, the proportion of returned ore is 27-38%, and the binary basicity of the sintered ore is 0.2-0.5, SiO 2 The content is 6.3-7.2%, MgO / Al 2 O 3 It is 1.1-1.45.

[0010] Furthermore, during pelletizing, the remaining solid fuel is pelletized; and during pelletizing, the proportion of solid fuel with a particle size less than 2 mm is more than 85%; and the water content of the sintering material is 7-13%.

[0011] Furthermore, after sintering, the yield of the sintered ore is 75.7-87.4%, and the drum strength is 61.4-69.3%. The beneficial effects of the present invention are:

[0012] The present invention adds solid fuels of different particle sizes in the batching and granulation processes respectively, and controls the water content, the amount of returned ore, the basicity and component content of the sintered ore, the thickness of the sintered material layer, the ignition process parameters and the negative pressure of the exhaust during the sintering process, thereby increasing the content of limonite.

[0013] In the present invention, limonite is produced in the form of acidic sintered ore, and solid fuel with a particle size of less than 2 mm is added during granulation, and the solid fuel with a particle size of less than 2 mm is evenly coated on the surface of the particles; this improves the kinetic combustion conditions of solid carbon, optimizes the mineralization conditions during the sintering process, and improves the yield and drum strength of limonite sintered ore;

[0014] The invention has simple process, safe operation and easy implementation, and can improve the yield rate and drum strength of limonite sinter. DETAILED DESCRIPTION

[0015] The present invention is described in detail below in conjunction with specific implementation modes.

[0016] The invention discloses a sintering and agglomeration method of limonite, comprising:

[0017] The amount of limonite added is 50-65% of the iron-containing material; the amount of solid fuel added is 5.2-8.7% of the sintering material;

[0018] Divide the solid fuel into two parts, one for batching and the other for pelleting;

[0019] During sintering, the thickness of the material layer is 850-1100mm; the ignition temperature is 1000-1100℃; the negative pressure is 3-7kpa; the ignition time is 2-5min; and the exhaust negative pressure is 14-18kpa.

[0020] Among them, when batching, 52-60% of the total solid fuel is added; and when batching, the proportion of solid fuel with a particle size of 2-5mm is more than 75%, the proportion of returned ore is 27-38%, and the binary basicity of sintered ore is 0.2-0.5, SiO 2 The content is 6.3-7.2%, MgO / Al 2 O 3 It is 1.1-1.45.

[0021] During pelletizing, the remaining solid fuel is pelletized; and during pelletizing, the proportion of solid fuel with a particle size less than 2 mm is more than 85%; and the water content of the sintering material is 7-13%.

[0022] Among them, after sintering, the finished product rate of sintered ore is 75.7-87.4%, and the drum strength is 61.4-69.3%.

[0023] Example 1

[0024] In the sintering and agglomeration method of limonite in this embodiment, the amount of limonite added is 65% of the iron-containing material, the proportion of hematite is 8% of the iron-containing material, the proportion of magnetite is 24%, and the proportion of miscellaneous minerals is 3%. The amount of solid fuel added is 8.7% of the sintering material.

[0025] When batching: the amount of solid fuel added is 52%; the proportion of solid fuel with a particle size of 2-5mm is 75%, and the proportion of returned ore is 38%. The binary basicity of sintered ore is 0.2, SiO 2 The content is 7.2, MgO / Al 2 O 3 The ratio is 1.1.

[0026] During pelletizing: the water content of the sintering material is 7%, the amount of solid fuel added is 48% of the total solid fuel, and the proportion of solid fuel with a particle size of less than 2 mm is 85%.

[0027] During sintering: the ignition temperature is 1000℃, the negative pressure is 7kpa, the ignition time is 2min, the exhaust negative pressure is 14kpa, and the material layer thickness is 850mm.

[0028] The yield of sintered ore is 75.7% and the drum strength is 61.4%.

[0029] Example 2

[0030] In the sintering and agglomeration method of limonite in this embodiment, the addition amount of limonite is selected to be 63.5% of the iron-containing material, the proportion of hematite is selected to be 13.4% of the iron-containing material, the proportion of magnetite is 20.1%, and the proportion of miscellaneous minerals is 3%. The addition amount of solid fuel is 7.5% of the sintering material.

[0031] When batching: the amount of solid fuel added is 58.6%; the proportion of solid fuel with a particle size of 2-5mm is 89.5%, and the proportion of returned ore is 28.6%. The binary basicity of sintered ore is 0.35, SiO 2 The content is 7.15, MgO / Al 2 O 3 The ratio is 1.35.

[0032] During pelletizing: the water content of the sintering material is 7.5%. The amount of solid fuel added is 41.4% of the total solid fuel, and the proportion of solid fuel with a particle size of less than 2 mm is 85.6%.

[0033] During sintering: the ignition temperature is 1070℃, the negative pressure is 6.5kpa, the ignition time is 3.1min, the exhaust negative pressure is 15.2kpa, and the material layer thickness is 914.5mm.

[0034] The yield of sintered ore is 78.5% and the drum strength is 63.4%.

[0035] Example 3

[0036] In the sintering and agglomeration method of limonite in this embodiment, the addition amount of limonite is selected to be 58.7% of the iron-containing material, hematite is 22.6%, magnetite is 15.7%, and miscellaneous minerals are 3%. The addition amount of solid fuel is 6.8% of the sintering material.

[0037] During batching: the amount of solid fuel added is 53.4%, the proportion of solid fuel with a particle size of 2-5mm is 87.4%, and the proportion of returned ore is 31%. The binary basicity of sintered ore is 0.39, SiO 2 The content is 6.85, MgO / Al 2 O 3 The ratio is 1.27.

[0038] During pelletizing: the amount of solid fuel added is 46.6% of the total solid fuel, the proportion of solid fuel with a particle size less than 2 mm is 88.4%, and the water content of the sintering material is 9.6%.

[0039] During sintering, the ignition temperature is 1065°C, the negative pressure is 5.8 kpa, the ignition time is 3.9 min, the exhaust negative pressure is 16.6 kpa, and the material layer thickness is 985.4 mm.

[0040] The yield of sintered ore is 80.7% and the drum strength is 65.6%.

[0041] Example 4

[0042] In the sintering and agglomeration method of limonite in this embodiment, the addition amount of limonite is selected to be 54.3% of the iron-containing material, hematite is 29.5%, magnetite is 13.2%, and miscellaneous minerals are 3%. The addition amount of solid fuel is 6.1% of the sintering material.

[0043] During batching: the amount of solid fuel added is 52.1%, the proportion of solid fuel with a particle size of 2-5mm is 89.4%, and the proportion of returned ore is 35.2%. The binary basicity of sintered ore is 0.45, SiO 2 The content is 6.21, MgO / Al 2 O 3 The ratio is 1.19.

[0044] During pelletizing: the water content of the sintering material is 12.1%, the amount of solid fuel added is 47.9% of the total solid fuel, and the proportion of solid fuel with a particle size of less than 2 mm is 91%.

[0045] During sintering, the ignition temperature is 1045°C, the negative pressure is 3.8 kpa, the ignition time is 4.7 min, the exhaust negative pressure is 17.2 kpa, and the material layer thickness is 1006.5 mm.

[0046] The finished product rate of sintered ore is 84.3% and the drum strength is 67.8%.

[0047] Example 5

[0048] In the sintering and agglomeration method of limonite in this embodiment, the amount of limonite added is 50% of the iron-containing material, the proportion of hematite is 35% of the iron-containing material, the proportion of magnetite is 12%, and the proportion of miscellaneous minerals is 3%. The amount of solid fuel added is 5.2% of the sintering material.

[0049] When batching: the amount of solid fuel added is 60%; the proportion of solid fuel with a particle size of 2-5mm is 87%, and the proportion of returned ore is 27%. The binary basicity of sintered ore is 0.5, SiO 2 The content is 6.3, MgO / Al 2 O 3 The ratio is 1.45.

[0050] During pelletizing: the water content of the sintering material is 13%, the amount of solid fuel added is 40% of the total solid fuel, and the proportion of solid fuel with a particle size of less than 2 mm is 92%.

[0051] During sintering: the ignition temperature is 1100℃, the negative pressure is 3kpa, the ignition time is 5min, the exhaust negative pressure is 18kpa, and the material layer thickness is 1100mm.

[0052] The yield of sintered ore is 87.4% and the drum strength is 69.3%.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A sintering agglomeration method for limonite, characterized in that: include: The amount of limonite added is 50-65% of the iron-containing material; the amount of solid fuel added is 5.2-8.7% of the sintering material; Divide the solid fuel into two parts, one for batching and the other for pelleting; During sintering, the thickness of the material layer is 850-1100mm; the ignition temperature is 1000-1100℃; the negative pressure is 3-7kpa; the ignition time is 2-5min; and the exhaust negative pressure is 14-18kpa.

2. The sintering agglomeration method of limonite according to claim 1, characterized in that: When mixing the ingredients, 52-60% of the total solid fuel is added; and when mixing the ingredients, the proportion of solid fuel with a particle size of 2-5mm is more than 75%, the proportion of returned ore is 27-38%, the binary basicity of the sintered ore is 0.2-0.5, the SiO2 content is 6.3-7.2%, and the MgO / Al2O3 is 1.1-1.

45.

3. The sintering agglomeration method of limonite according to claim 2, characterized in that: During pelletizing, the remaining solid fuel is pelletized; and during pelletizing, the proportion of solid fuel with a particle size less than 2 mm is more than 85%; and the water content of the sintering material is 7-13%.

4. The sintering agglomeration method of limonite according to claim 1, characterized in that: After sintering, the finished product rate of sintered ore is 75.7-87.4%, and the drum strength is 61.4-69.3%.