JPH0588292B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a raw material loading method in a blending yard. (Conventional technology) There are 20 to 30 types of main raw materials for sintered ore, and in order to stabilize the quality of sintered ore, it is necessary to thoroughly mix these various raw materials in a blending yard in advance. . The method of loading raw materials in such a blending yard is shown in outline in Figure 1. Various raw materials are first stored in storage hoppers 1, then quantitatively cut out from each hopper 1, and conveyed to the belt conveyor 2. The stacker is then transported to the bedding stacker 3 (hereinafter referred to as stacker). The stacker 3 reciprocates within a set range of a blending yard (hereinafter referred to as yard), and the amount of raw material cut out from each hopper 1 is determined by the moving speed of the stacker 3. The material will be stacked in the yard according to its thickness (raw material loading amount). The raw materials stacked in this manner are discharged by the double-wheel reclaimer 4 as shown in FIG. 2 as follows. That is, the bucket foils 5, 5 installed at a constant interval L in the width direction of the mountain are moved back and forth in the width direction of the mountain, and the bucket foils 5, 5 themselves are rotated and moved to the sides in the width direction of the mountain. I am trying to get rid of the attached raw materials. According to this method, when the bucket wheels 5, 5 are at the position X or Z, the raw material group G stacked on the side of the pile and the raw material groups A to G stacked on the central part of the pile are delivered. Also Bucket Foil 5,
When the position of 5 is Y, raw material groups C to G are dispensed. For this reason, if the components of the raw material groups A to G or the quality such as particle size are significantly different, the quality of the raw material dispensed with the reciprocating cycle of the double foil reclaimer 4 will vary. Therefore, the order and combination of raw materials to be stacked should be determined so that the quality of raw material groups A to G is constant, and the quality fluctuations of raw materials that occur due to the period of reciprocating motion of the double-wheel reclaimer 4 are suppressed as much as possible. There is a need to choose. In addition, among the quality of raw materials, SiO ₂ and particle size are particularly important items to control. This is _SiO2
Fluctuations in sintered ore greatly affect quality fluctuations such as RDI and reduction rate, and fluctuations in particle size are a major cause of permeability fluctuations during sintered ore firing, which in turn causes a decrease in sintering yield. It's for a reason. In addition, it is necessary to particularly consider the loading method for composition-adjusted raw materials such as soft silica, serpentine, and scale, and for raw materials with large quality fluctuations, but generally, for such raw materials, hopper 1 It is known that fluctuations can be suppressed by minimizing the amount of material cut out (T/H), extending the stacking time, and increasing the number of stacked layers. Therefore, for component-adjusted raw materials and raw materials with large quality fluctuations, a method is used to cut them out at the lowest limit of cutting capacity as much as possible. Therefore, it is necessary to select the order and combination of the raw materials of raw material groups A to G so that the average values of SiO ₂ and particle size of each of raw material groups A to G are the average values of the entire pile of raw materials. . This is because the raw material group is a collection of raw materials cut out from each hopper 1, so it is necessary to appropriately select each raw material and the amount of raw material cut out (T/H) when cutting out from each hopper 1. However, as mentioned above, the types of raw materials range from 20 to
There are 30 types of raw materials, and the loading amount of each raw material ranges widely from several hundred tons to over 10,000 tons, making it difficult and common to select the appropriate loading order and combination of raw materials. Currently, the amount of raw materials to be cut out (T/H) and combinations are roughly determined and stacked based on the characteristics of the SiO ₂ particle size of each raw material. In addition, as a method to make the SiO ₂ particle size of the entire raw material stacked in the blending yard uniform,
62-15617 has been proposed, but this method is applicable only when the raw material cutting hopper 1 is one tank, and normally, multiple raw material cutting hoppers are stacked. , it is not a technology that can be applied to all stowage operations. (Problem to be solved by the invention) As a result, the average of each of raw material groups A to G
Although each average value of SiO ₂ particle size is approximately at the same level as the average value of the whole pile in some parts, there are many parts that deviate greatly from the average value of the whole pile, for example, raw material group A. and the average SiO ₂ of raw material group C,
If there is a large difference in particle size, when discharging a pile of raw materials piled up with the double foil reclaimer 4, if the bucket foils 5, 5 are in position X or Z, raw material group A and raw material group G are discharged. It mixes into the raw materials, but the position of bucket foil 5, 5 is Y.
In this case, raw material groups C to G will be mixed into the discharged raw material, and the SiO ₂ particle size of the discharged raw material will vary greatly depending on the position of the bucket foils 5, 5. This in turn causes the particle size of SiO ₂ , the main raw material for sintering, to fluctuate and the sintered metal to be formed.
This causes variations in quality such as RDI and reduction rate, and also causes variations in air permeability due to variations in particle size, resulting in a decrease in sintering yield. (Means for Solving the Problems) In order to solve these problems, the present invention provides a combination of SiO ₂ and particle size of the stacked raw materials, which is a suitable combination of stacked raw materials that can suppress variations in particle size as much as possible. (1) In a method of stacking various raw materials using a blending stacker that moves back and forth within a specified range in a blending yard, Average of raw material groups divided by dividing raw materials into multiple parts
When calculating the SiO ₂ content and determining the amount of raw material cut out from multiple raw material cutting hoppers for each divided raw material group, the amount of raw material cut out from each raw material cutting hopper (T/H) is assumed to be constant. Calculate the transfer amount (T/H) of the raw material with the highest SiO ₂ content and the raw material with the lowest SiO ₂ content from each raw material combination for all raw material combinations,
A method for loading raw materials in a blending yard, characterized in that raw materials are cut and stacked from a plurality of hoppers in the order of the combinations with the smallest transfer amount, (2) a plurality of raw materials for each divided raw material group; When creating the raw material cutting schedule from the raw material cutting hopper, the raw material cutting amount (T/H) from the raw material cutting hopper is not constant, and
For raw materials whose components are adjusted such as scale, and raw materials that are considered to have large quality fluctuations, avoid cutting out multiple raw materials, and fix the raw material cut-out amount (T/H) at or close to the lower limit of cutting equipment capacity, and reduce the remaining Amount of raw material cut out (T/
H) A raw material loading method in a blending yard according to the above item (1), characterized in that the raw material combination is selected by assuming that each remaining raw material is equal; (3) the raw material from the raw material cutting hopper; When selecting a combination, combinations of fine raw materials with an average particle size of 1 mm or less or coarse raw materials with an average particle size of 3 mm or more are excluded from the range. The gist of this document is the method of loading raw materials in the blending yard described in section 1). (Function) By implementing the present invention, each of the raw material groups A to G in the pile of raw materials piled up in the blending yard.
The SiO ₂ particle size value is the same as the SiO ₂ particle size value of the entire pile, and when the raw material is discharged with the double foil reclaimer 4, the fluctuation of the SiO ₂ particle size of the raw material depending on the position of the bucket foils 5, 5 is It can be held down. As a result, it is possible to improve the sintering yield by reducing quality fluctuations in sintered ore RDI, reduction rate, etc., and reducing fluctuations in air permeability. (Example) As an example, an example of creating a stowage plan when the number of raw material cutting hoppers is three tanks will be shown. First, in accordance with each target component value of sintered ore, each target component value of the entire raw material to be stacked in the blending yard and a loading plan for each raw material are created in advance. Next, this overall loading plan is divided into a plurality of loading plans for each raw material for the entire raw materials to be loaded in the blending yard. At that time, the dividing method is as follows: the average SiO ₂ of each divided particle, the average SiO ₂ of the entire raw material,
Adjust to match the particle size as much as possible. The loading plan after division is shown in Table 1. The average SiO ₂ and particle size in this plan are 3.836% and 2.268 mm, and these values select the combination of raw materials to be cut out from the raw material cutting hopper 1. The average SiO ₂ becomes the standard of time, and the particle size becomes the standard.

[Table] Next, from among these loading plans for each raw material, the weighted average SiO ₂ when cutting raw materials from the raw material cutting hopper 1 in the 3 tanks will be the average SiO ₂ value of the plan in Table 1. Select two raw materials and determine the cutting amount (T/H) for each raw material. The method is
First, the planned loading amount (T/H) of the blending stacker 3 in this plan is determined. This is the cutting amount (T/H) when raw material is cut out from the three-tank raw material cutting hopper. Next, assuming that the cutting amount (T/H) of each raw material cutting hopper 1 is the same, and using the following formula, for each raw material combination, the highest SiO ₂ raw material and the highest SiO 2 raw material are determined.
If the raw material with low SiO ₂ is transferred, the target SiO ₂
Calculate the amount of transfer required to achieve each. Transfer amount (T/H) = (Target SiO ₂ %--SiO ₂ -T%) x BD
ST T/H/High-SiO ₂ raw material SiO ₂ %-Low-SiO ₂ raw material SiO ₂
% Target SiO ₂ %: Cutting amount of three raw materials (T/H)
Target SiO ₂ % when determining SiO ₂ -T%: Cutting amount of three raw materials (T/H)
Average SiO ₂ % BDST T/H: Target T/H of the blending stacker during the loading period of the divided loading plan High-SiO ₂ raw material SiO ₂ %: Among the three raw materials number one
High SiO ₂ raw material SiO ₂ % Low-SiO ₂ raw material SiO ₂ %: The highest among the three raw materials
SiO ₂ % of raw materials with low SiO ₂ Table 2 shows the blending stacker target T/
The calculation results of the transfer amount for all combinations when H is 1200T/H are shown, and three raw materials are selected in the order of raw material combinations with the smallest value. Here, the combination of brands B, C, and F requires the least amount of component adjustment and can be adjusted to the target component. The results are shown in Table 3. Brand C, which is a low-SiO ₂ raw material, and brand F, which is a high-SiO ₂ raw material.
By transferring 2T/H, the average SiO ₂ can be adjusted to the target value.

【table】

【table】

【table】

【table】

【table】

【table】

【table】

【table】

[Table] Here, the reason for selecting combinations based on the size of the transfer amount (T/H) is simply the average of the same T/H.
When determining the quality of a combination based on the difference between SiO ₂ and the target SiO ₂ , even if the SiO 2 is closest to the target SiO ₂ , if the difference in SiO ₂ between the raw materials is small, it will be completely adjusted to the target SiO ₂ . This is because large adjustments are required to achieve this, and in extreme cases, adjustments may not be possible. In addition, as selection criteria for this combination, fine raw materials with an average particle size of 1 mm or less, or particles with an average particle size of 3
It is effective to exclude combinations of coarse raw materials of mm or larger from the selection range. This is because when only fine-grained raw materials are stacked, the rolling of the raw materials on the pile is small, and the raw materials are only stacked at the top of the pile, and when only coarse-grained raw materials are stacked, the rolling of the raw materials on the pile is small. This is because the rolling motion is large, and the raw materials are only piled up on the sides of the pile, causing quality fluctuations. Furthermore, the reason why fine raw materials are limited to 1 mm or less and coarse raw materials to 3 mm or more is because normal raw materials can be classified into fine or coarse raw materials based on these values. In addition, for composition-adjusted raw materials such as soft silica, serpentine, and scale, and raw materials that are considered to have large quality fluctuations, simultaneous cutting of multiple raw materials should be avoided, and the raw material cutting amount (T/H) should be set to the lower limit of cutting capacity. Alternatively, a method can be used to cut out the material at a value close to that value, extend the stacking time, increase the number of stacked layers, and reduce quality fluctuations. Therefore, when selecting the optimal combination of raw materials, raw materials with large fluctuations should be cut at a low cutting rate (T/H).
It is desirable to fix the transfer amount (T/H) by the following formula and select a combination based on the magnitude. Transfer amount (T/H) = (Target SiO ₂ %--SiO ₂ -T%) x BD
ST T/H/High-SiO ₂ raw material SiO ₂ %--Low-SiO ₂ raw material Si
O ₂ % SiO ₂ −T%=SiO ₂ −i%×i Raw material T/H/BDST T/H
+ (High-SiO ₂ raw material SiO ₂ % + Low-SiO ₂ raw material SiO ₂ %) / × (BDST T / H-i raw material T / H) / BDST T / H Target value SiO ₂ %: Cutting amount of three raw materials (T/H)
Target SiO ₂ % SiO ₂ -T% when determining
Average SiO ₂ % when the cutting amount (T/H) of two raw materials is constant SiO ₂ -i%: SiO ₂ % of the raw material with large fluctuations i Raw material T/H: The cutting amount (T/H) of the raw material with large fluctuations H) BDST T/H: Target T/H of the blending stacker during the loading period of the divided loading plan High-SiO ₂ % Raw material SiO ₂ %: Among the two raw materials
High _SiO2 raw material _SiO2 % Low- _SiO2 raw material _SiO2 %: _SiO2 among the two raw materials
In this way, the combination of raw materials and the cutting amount ( _T /H) are determined, but the amount of work (work time) due to this combination of raw materials is It is determined by the raw material with the shortest possible stowage time determined by its planned stowage amount. Table 4 shows the calculation results for the amount of work (work time).
Brand B has only 8 hours and 3 minutes in this combination, which is shorter than other brands. Therefore, the amount of work (work time) for this raw material combination is 8 hours and 3 minutes.

[Table] In the same manner, plans are sequentially created while excluding each planned raw material from the selection range of raw material combinations. The stowage plan created in this way is shown in Table 5. In this way, it is possible to create a plan for each stowage operation such that the average SiO ₂ of each raw material is always constant.

[Table] (Effects of the invention) The present invention stabilizes the quality of SiO ₂ in the width direction of the mountains in the blending yard, particle size, etc., which in turn stabilizes the quality of the main raw material for sintering, and improves the quality of sintered ore.
Quality such as RDI and reduction rate is stabilized, and the sintering yield can be improved by stabilizing air permeability during sintering.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of equipment used in blending work. FIG. 2 is a diagram illustrating a method of discharging raw materials in a blending yard. 1...Storage hopper, 2...Belt conveyor,
3...Blending stacker, 4...Double foil reclaimer, 5...Bucket foil.

Claims (1)

[Claims] 1. In a method of stacking various raw materials using a blending stacker that moves back and forth within a designated range in a blending yard, each raw material is divided into a plurality of parts, and the divided raw material groups are When calculating the average SiO ₂ content and determining the amount of raw material cut out from multiple raw material cutting hoppers for each divided raw material group, the amount of raw material cut out from each raw material cutting hopper (T/H) is kept constant. The raw material with the highest SiO ₂ content and the highest SiO ₂ content among the combinations of raw materials
A blender characterized in that the transfer amount (T/H) of raw materials with a low content rate is calculated for all combinations of raw materials, and the raw materials are cut out from a plurality of hoppers and stacked in the order of the combinations with the smallest transfer amount. Raw material loading method in the ding yard. 2 When creating the raw material cutting schedule from multiple raw material cutting hoppers for each divided raw material group, the raw material cutting amount (T/H) from all raw material cutting hoppers is not constant, For raw materials with equal composition adjustment and raw materials that are considered to have large quality fluctuations, avoid cutting out multiple raw materials, fix the raw material cutting amount (T/H) at the lower limit of cutting equipment capacity or a value close to it, and The raw material loading method in a blending yard according to claim 1, characterized in that the raw material combination is selected by assuming that the raw material cut-out amount (T/H) is equal for each remaining raw material. 3 When selecting the combination of raw materials from the raw material cutting hopper mentioned above, the combination of fine raw materials with an average particle size of 1 mm or less or coarse raw materials with an average particle size of 3 mm or more is within the range A method for loading raw materials in a blending yard according to claim 1, characterized in that: