A method for determining sintering moisture

Abstract

The present invention discloses a method for determining sintering moisture, which first measures the wet capacity of materials used in various ore blending of sintering material piles, and then calculates the moisture content of sintering mixtures according to formula (I). The method for determining the moisture content of sintering mixtures provided by the present invention can accurately calculate the appropriate range of sintering moisture according to the formula. The method is simple, easy to implement, accurate and reasonable, and can provide a reference for production, avoiding the need to explore the granulation moisture during the production process after the ore blending structure of the material pile is adjusted, thereby effectively improving the stability rate of various indicators of sintered ore.

Description

Technical Field

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

[0002] In the steel production process in my country, iron ore sintering is an important method to provide blast furnaces with iron-making raw materials with excellent metallurgical properties. The moisture content of the raw materials used in sintering has a great influence on pelletizing. If the raw materials are not moist, it is difficult for the green balls to grow. Because in the early stage of ball formation, there is insufficient capillary water between the ore materials, the gaps between the ore particles may be filled with air, and the bonding between the particles is very fragile. However, materials with insufficient moisture can be supplemented with water during ball making. If the raw materials are too wet, the mother balls are easy to stick to each other or deform, making the green balls uneven in size. Over-wet green balls have low strength, high plasticity, and are easy to change, affecting the permeability of the material layer. The most suitable moisture content of the mixture for sintering is to make the mixture achieve the highest ball formation rate or maximum permeability to evaluate. However, the suitable moisture content range is small. When the actual moisture content exceeds ±0.5%, it will have a significant impact on the ball formation of the mixture. Different sintering materials have different suitable moisture contents. Generally speaking, the finer the particle size of the material and the larger the specific surface area, the higher the required suitable moisture content. In addition, the appropriate moisture content is closely related to the type of raw materials. The moisture content required for sintering of loose and porous limonite can be controlled at 14%~18%, while the appropriate moisture content for sintering of dense magnetite is 6%~10%, and hematite is in the middle at 8%~12%. The figure below shows the relationship between the ball formation rate and moisture content of a certain material. Therefore, the appropriate amount of sintering water plays an important role in improving the pelletizing effect of iron ore powder. During the production process, the moisture content is often adjusted in real time based on experience. When the ore distribution structure is adjusted significantly, the sintering moisture range cannot be accurately known when the upper and lower stock piles are replaced, which will lead to untimely adjustment of the sintering moisture content, resulting in fluctuations in the quality of the sintered ore and delayed adjustment of process parameters. Summary of the invention

[0003] The object of the present invention is to provide a method for determining sintering moisture.

[0004] The object of the present invention is achieved by providing a method for determining sintering moisture, which first measures the wet capacity of materials used in various ore blends in a sintering stockpile, and then calculates the appropriate range of sintering moisture according to formula (I).

[0005] Y 混合料水分 = A 配比 *A 湿容量 +B 配比 *B 湿容量 +C 配比 *C 湿容量 ...-K 修 (I);

[0006] Among them, (A配比 +B 配比 +C 配比 ...) = 100%, A, B, C... are the materials in the ore distribution structure, and K is the correction value, which is related to the proportion of dust removal ash used in the machine head, quicklime, material moisture, etc.

[0007] The wet capacity refers to the maximum water content that a unit mass of mineral can maintain in a naturally stacked state. When measuring the wet capacity, the material is dried in an oven at 105°±5° for more than two hours before measuring.

[0008] The beneficial effects of the present invention are as follows: the method for determining the moisture content of the sintering mixture provided by the present invention can accurately calculate the appropriate range of sintering moisture according to the formula. The method is simple, easy to implement, accurate and reasonable, and can provide a reference for production, avoiding the need to grope for granulation moisture during the production process after the ore mixing structure of the material pile is adjusted, thereby effectively improving the stability rate of various indicators of the sintered ore. DETAILED DESCRIPTION

[0009] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0010] The present invention provides a method for determining sintering moisture. The method first measures the wet capacity of materials used in various ore blends in the sintering material pile, and then calculates the appropriate range of sintering moisture according to formula (I).

[0011] Y 混合料水分 = A 配比 *A 湿容量 +B 配比 *B 湿容量 +C 配比 *C 湿容量 ...-K 修 (I);

[0012] Among them, (A 配比 +B 配比 +C 配比 ...) = 100%, A, B, C... are the materials in the ore distribution structure;

[0013] The K value is mainly adjusted according to the proportion of dust removal ash, quicklime, material moisture, etc. It is an empirical constant value, which is obtained by exploring different raw material structures. For specific calculations, please refer to: the CaO content of quicklime is 85%, so the theoretical amount of water added for complete digestion of 1 ton of quicklime is 0.27 tons. If the quicklime is not completely digested in the sintering batching room, a certain amount of water needs to be added. When the machine head dust removal ash and returned ore are used as dry materials, a certain amount of water needs to be added to improve the quality of pelletizing.

[0014] The wet capacity refers to the maximum water content that a unit mass of mineral can maintain in a naturally stacked state. When measuring the wet capacity, the material is dried in an oven at 105°±5° for more than two hours before measuring.

[0015] The present invention is further described below by way of examples.

[0016] Examples 1-5 are calculations of the most suitable granulation moisture for the D1#-D5# sintering stockpile at the Honghe base of Kunming Iron and Steel. Tables 1-5 are the ore distribution and wet capacity of the D1#-D5# stockpile, respectively.

[0017] Example 1 Determination of sintering moisture in D1# sintering pile

[0018] Table 1 Ore blending and wet capacity of D1# sintering stockpile

[0019]

[0020] The actual sintering granulation moisture content of the material pile in production is 8.57%. According to formula (I), the optimal theoretical sintering granulation moisture content of D1# material pile is 8.5%. Only fine-tuning is required in production, which can avoid the situation where the process parameter adjustment is delayed and the quality of the sintered ore is reduced due to the inability to accurately control the sintering granulation moisture content after a large adjustment of the material pile structure and the ore blending materials.

[0021] Example 2 Determination of moisture content during sintering of D2# pile

[0022] Table 2 Ore distribution and wet capacity of D2# sintering stockpile

[0023]

[0024] According to formula (I), the sintering moisture content of D2# pile is 7.96%, and the actual sintering moisture content of the pile is 8.00%.

[0025] Implementation 3 Determination of sintering moisture in D3# sintering pile

[0026] Table 3 Ore distribution and wet capacity of D3# sintering stockpile

[0027]

[0028] According to formula (I), the sintering moisture content of D3# pile is 9.11%, and the actual sintering moisture content of the pile is 9.20%.

[0029] Implementation 4 Determination of sintering moisture in D4# sintering stockpile

[0030] Table 4 Ore distribution and wet capacity of D4# sintering stockpile

[0031]

[0032] According to formula (I), the sintering moisture content of D3# pile is 7.84%, and the actual sintering moisture content of the pile is 7.90%.

[0033] Implementation 5 Determination of sintering moisture in D5# sintering pile

[0034] Table 5 Ore distribution and wet capacity of D5# sintering stockpile

[0035]

[0036] According to formula (I), the sintering moisture content of D3# pile is 7.49%, and the actual sintering moisture content of the pile is 7.60%.

[0037] Experimental Example 6 The moisture content of sintering mixtures of 5 piles (used for more than two months) with large changes in the ore distribution structure before and after use were randomly selected from the Honghe Base of Kunming Iron and Steel Co., Ltd. for comparison. The results are shown in Table 6.

[0038] Table 6 Comparison of sintering moisture before and after using the method of the present invention at a certain base

[0039]

[0040] Result analysis: From Table 6, it can be seen that the deviation after using the method of the present invention is ±0.25%, which is significantly lower than the deviation before use. After adopting the method of the present invention, when the pile structure is greatly adjusted, the moisture content of sintering and granulation can be accurately controlled, and the fluctuation of sintered ore quality caused by moisture deviation (insufficient or over-wet) can be reduced.

Claims

1. A method for determining sintering moisture, characterized in that: The method first measures the wet capacity of the materials used in the various ore batches of the sintering material pile, and then calculates the appropriate range of sintering moisture according to formula (I). Y 混合料水分 =A 配比 *A 湿容量 +B 配比 *B 湿容量 +C 配比 *C 湿容量 ...-K 修 (I); Among them, (A 配比 +B 配比 +C 配比 ...) = 100%, A, B, C... are the materials in the ore distribution structure, K is the correction value and is related to the use ratio of dust removal ash from the machine head, quicklime, and material moisture. When applied, K 修 The value is 1.7%.

2. The method for determining sintering moisture according to claim 1, characterized in that: The wet capacity refers to the maximum water content that a unit mass of mineral can maintain in a naturally stacked state. When measuring the wet capacity, the material is dried in an oven at 105℃±5℃ for more than two hours before measuring.

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