JPS6215617B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for stacking betting piles of raw materials for steel manufacturing. In general, it is convenient for the operation of raw materials to be supplied to sintering plants, blast furnaces, etc. if the range of fluctuation in their composition is as small as possible. Conventional raw material processing techniques have mainly focused on this point, and various brain-densing techniques have been developed. A typical method for stacking fine ore and lump ore in bedding piles is the Chevron method, which creates a pile with a triangular layered cross-sectional shape, as shown in FIG. This conventional pile stacking method uses a self-propelled stacker to stack ores of different chemical compositions, A to G, in order from the top in a pre-planned order, as shown in Figure 1. This is the way to attach it. The order of stacking is to start with ore A, which is a brand with a chemical composition similar to the final average chemical composition of pile P. Among the piled ore groups, a method is used in which the ores are stacked in the intermediate portions C to E of the pile P, excluding the first and last. On the other hand, the piles stacked as described above are removed using a double wheel reclaimer as follows. That is, a pair of bucket wheels 1, 1' installed at a constant interval L in the width direction of the pile are reciprocated in the width direction of the pile P while rotating and circulating themselves so that they can be applied to the sides of the pile in the width direction. By moving it, we cut out raw materials with small variations. With this method, since two bucket wheels 1 and 1' are installed at a constant interval L, they can be placed between W, W' and Z, Z' as shown in Figure 1-b. When the material is moved in parallel, in the case of special component raw materials stacked in the middle part of the pile C to E, in the range of left and right wheel positions W to Z and W' to Z', the pile is particularly moved as shown in Figure 1-c. In addition to periods when the material is not cut out at the ends corresponding to both ends in the width direction, the amount of cutout also varies greatly, resulting in non-uniformity between the center portion and the end portions. This results in supplying ore with periodically varying components to the next sintering step, which causes deterioration in the quality of the sintered ore. In short, this is because the scraping width l of the bucket wheels 1, 1' is constant, so the volume (pile cross-sectional area) to be scraped varies at positions near both ends of the left and right piles. The present invention solves the problems of the prior art as described above, and solves the problem of the final average chemical composition of the bedding pile cut out by a double-wheel reclaimer and obtained by stowing according to the Chevron method. Determine the loading amount for each brand based on the brand and the chemical composition of each brand, divide each brand into two groups consisting of products that are distinguished by the positive or negative relative to the target value of the chemical composition, and Select one item from the group that is closer to the target value for the chemical components mentioned above, combine them in order to create a group of two items, calculate the loading amount of each item, and calculate the amount of peace each item has. In consideration of the stacking capacity determined by the corner and stacking position in the pile height direction, and the appropriate stacking quantity determined by the relationship between the group brand and the average chemical composition of the pile, multiple quantities are determined. By dividing the amount of each divided brand into two brands in order of the final target value of the pile chemical composition and stacking them alternately, the number of divided brands can be stacked. I have overcome it,
It is suitable for supplying bedding ore of uniform composition to the next process. The configuration will be explained in more detail below. In the present invention, raw material was cut out from the bedding pile using a double-wheel reclaimer, and the relationship between the composition variation value in the width direction of the bedding pile and the composition variation value of the sintered ore product was investigated. It has been found that there is a strong correlation between the component fluctuation values and the component fluctuation values of sintered mineral products, and this pile stowing method was constructed based on this knowledge. The present invention is a method for loading a bedding pile using the Chevron method on the premise that it is cut out using a double-wheel reclaimer. This is a method in which the loading amount of each brand is determined based on the chemical composition, and the determined loading amount is loaded as follows. The case of sintered ore will be explained below. First, the average chemical composition of the entire pile is determined in advance so as to match the chemical composition of the finished product of sintered ore. for example,
Based on Table 1, using the example of SiO ₂ , if the final target composition of the pile is 5.47%, inventory and Select the brand to be used from the incoming raw materials.

[Table] Next, the loading amount for each brand is determined to be the final average chemical composition value of the pile. After that, a predetermined amount of each brand is stacked one after another, but it is known that if the standard brand is stacked in the center of the pile and the special brand is stacked in the upper part of the pile, products with less fluctuation in composition can be obtained. Therefore, the present invention utilizes this point to carry out stowage as follows. That is, as shown in Fig. 3, those whose SiO ₂ content is either positive or negative with respect to the target component S ₁ = 5.47% are separated into two groups, and each group is divided into two groups. From among them, select one that is closer to the target value and combine them in order to create a group. By performing such processing, the components of special brands that are a direct cause of component fluctuations will be diluted, reducing the influence on component fluctuations, and reducing the loading of one brand. This is useful for calculating the number of divisions when dividing a quantity into multiple parts and stacking them. When stacking these combined brands, each brand should be distributed evenly over the entire slope of the pile to prevent it from being concentrated at the foot of the pile, for example. Each brand is divided into several parts, and each divided unit quantity is divided into several batches and stacked to a predetermined stowage quantity. The number of divisions for each brand is determined by selecting from among the two groups mentioned above and the pileable amount determined for each brand, which is regulated by each brand's unique angle of repose and position in the pile height direction. The amount that can be loaded is determined by taking into consideration the amount that is preferable for bringing the average component value of the combined group brands closer to the final component target value of the pile.

【table】

【table】

[Table] The division number calculation method is explained below. As shown in Table 3, each brand has its own angle of repose (accumulation angle of powdered material), so when stacked, some brands may run out on the slope of the pile. Also, depending on the amount of stowage, a phenomenon occurs in which the piles are concentrated at the foot of the mountain, so the appropriate amount that can be stowed is determined according to the height of the pile and the angle of repose of each brand. However, for special brands, the specific components they contain are significantly larger than other brands, so in order to take into account the effect on component fluctuations, it is necessary to ensure that they are distributed evenly over the entire surface of the mountain slope and that they are different from other brands. The layer thickness is set to be the smallest possible to facilitate mixing. For other brands, the amount of cargo loaded is large, so there is a low possibility that cargo will run out, but there is a high possibility that the accumulation will be concentrated at the foot of the pile. The number of divisions must be set as small as possible without reducing work efficiency. Table 3 shows the relationship between the angle of repose for each brand and the pileable amount depending on the pile position for the calculation method described above. Each brand is stacked multiple times based on the number of divisions determined in this way. In actual stacking, products that are closer to the final target component of the pile are combined, and two brands that form this combination are stacked alternately. These relationships are shown in Table 2 and Figure 2. Examples of the present invention will be described below. First, the target component of the entire pile, that is, the average component (S ₁ ), is set so that the target component of the sintered ore is set in advance. Next, based on the chemical composition (S) of the brands that has been analyzed in advance and is known, loading brands A to G are selected, and the loading amount (T) for each brand is adjusted to the chemical composition (S ₁ ). ₁ ) Determine. The example in Table 1 shows the case where the target chemical component value is SiO ₂ = 5.47%, but each brand is
As shown in the figure, the items are divided into two groups using positive and negative signs, and within each group, the item closest to the target value is selected in order to form a combination. However, in the example, it was not evenly divided into groups, so Gs with a large amount of cargo was
It was distributed to each of Cs and Ds and balanced. Next, the combined brands were divided into predetermined loading amounts as shown in Table 2 and stacked. The number of divisions was determined as follows. In other words, when the height of the entire pile is 15 m, the divided stowage amount of each brand is the upper and lower limits of the stowage amount in the direction of pile height shown in Table 3 (each stowage amount for A to G brands). Loading amount with layer thickness corresponding to the position
The loading amount was selected within the range of (max, min), and the number of divisions was calculated by dividing the loading amount by the loading amount for each brand shown in Table 1. For example, pile A brand with a height of 0 to 5 m.
The division amount (loading amount) when stacking between 700
In the range of ~1000t, in the case of C, the amount of division is adjusted in the range of 200 to 300t, which is the loading amount between 10 and 15 meters, since it is stacked upward. This is shown in Table-2. Based on the number of stowage divisions and division amounts determined in this way, the method of grouping and combining brands shown in Figure 3 and each brand shown in Table 1 are used for actual stowage. Considering the ingredients contained in
The average component (S ₂ ) when two types of brands are combined is determined for each combination group. Next, the average component of the entire pile (S ₁ ) and the average component (S ₂ ) between each combination group, starting from the smallest value of S ₁ −S ₂ , that is, the average component of the entire pile (S ₁ ) The stacking is started sequentially from the combination group having the average component (S ₂ ) close to , and two brands are stacked alternately to form a pile. After implementing this bedding method to create a pile, samples were cut out using a double-wheel cutting device and sampled at predetermined positions.The degree of variation in SiO ₂ (δSiO ₂ ), which is one of the sintered component management indicators, was measured. The results shown in Figure 4 were obtained. As is clear from Figure 5, the conventional
While the variation (monthly average value) of SiO ₂ was 0.124%, after implementing the method of the present invention, it was
Good results were obtained, with a significant decrease of 0.081%. As explained above, according to the loading method of the present invention,
It becomes possible to obtain sintered ore of uniform composition no matter where it is cut from the entire pile, making it possible to significantly stabilize the quality of the sintered ore.

[Brief explanation of the drawing]

Figure 1a is a cross-sectional view of the bedding pile, Figure 1b is a diagram showing the relationship between the cutting bucket wheel and the pile width direction, and the moving process of one cycle of the bucket wheel, and Figure 1c is a diagram showing the relationship between the cutting bucket wheel and the pile width direction. Figure 2 shows the changes in the cutting amount of special brands, Figure 2 shows the pile loading situation, Figure 3 shows the combinations of loaded brands, Figure 4 shows the sintered ore before and after implementing the method of the present invention. FIG. 3 is a diagram showing fluctuations in component SiO ₂ . P... Betting pile, 1, 1'... Wheel, A, B, F, G... Standard brand ore, C,
D, E...Special brand ore, l...Wheel width, L
...Distance between wheels.

Claims (1)

[Scope of Claims] 1. Target value of the final average chemical composition of the betting pile cut out with a double wheel reclaimer and obtained by stacking according to the Chevron method, the loading brand, and the chemical composition of each brand. First, the loading amount for each brand is determined, and each brand is divided into two groups, each of which has a positive or negative difference with respect to the target value of the chemical component, and within each group, the amount of the chemical component mentioned above is determined. Create a group consisting of two items by selecting one item that is closer to the target value and combining them in order, and then calculate the stowage amount of each item by multiplying the angle of repose of each item by the pile height direction. Taking into consideration the stacking capacity determined by the stacking position and the appropriate stacking quantity determined by the relationship between the group brand and the average chemical composition of the pile, the pile is divided into multiple quantities, and each of the divided volumes is A method for stacking a betting pile, characterized in that the amount of each brand is combined in order from the one closest to the final target value of the pile chemical components, and two brands are stacked alternately by the number of divisions.