JPS6254173B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention mainly relates to a method for homogeneously loading raw materials for sintered ore. In the ironmaking process, it is common practice to feed powdered iron ore to a blast furnace in the form of sinter or pellets. This is because operating the furnace using homogeneous raw materials over a long period of time guarantees the most efficient and stable operation, and as a result, the cost of manufactured pig iron can be reduced. For this reason, large amounts of iron ore are purchased in powder form, or ore purchased in bulk is crushed into powder, and this is stacked using the siebron method, parallel pile method, or horizontal method to prepare a large amount of homogeneous raw material. This is then cut out one by one to produce sintered ore and pellets, and iron is made using raw materials with stable ingredients and quality over a long period of time. The problem here is the method of homogenizing the raw materials, which is the first step of homogenization. In other words, as proposed in Japanese Patent Publication No. 54-40441, attempts have been made to limit the loading positions of raw material ores that have a negative impact on homogenization in order to alleviate the negative impact, but the results have not been completely homogenized. This is the actual situation. As shown in Figure 1, when viewed from the loading step surface, this appears to be an attempt to achieve homogenization, but if we consider the state in which this is cut out from the pile, it becomes clear that the
As shown in the figure, this method is not necessarily satisfactory. This point will be considered based on FIGS. 1 and 2. Now, the brands of each stowage layer in Figure 1 are A, B, C,
In the case of D, each block shown in Table 2 of the embodiments of the present invention described later is composed of only the same brand, and the double foil type cutting device 1 shown in FIG.
Looking at the area by brand extracted in step 2, each brand A,
There is a large difference in the areas indicated by B, C, and D, and there is also a large difference in the structure of the units cut out onto the conveyor belt. This clearly shows that this proposal cannot achieve its purpose no matter where the ore containing special components is loaded. In other words, a sufficiently homogeneous blend of raw materials cannot be obtained. Moreover, this fluctuation has one cycle for each reciprocation of the double-foil cutting device, and this fluctuation occurs repeatedly. This proposal has such problems, and as a result, the monthly average variation in basicity of the cut raw material is as large as 0.025. The present invention does not have the problems of the conventional method described above,
This method was developed as a result of experiments and studies to find a method that achieves even better homogenization.The main feature of this method is that it determines the target composition and particle size of the powdered material based on the composition and quality of the sintered ore. The blending ratio of each brand is set based on the particle size of each brand of powdered stowage material, and the blending weight of each brand is calculated based on this blending ratio and the total weight of the stowage pile plan. The total weight of the pile plan is divided into a plurality of predetermined equal amounts to form stowage blocks, and the various brands are distributed to each stowage block in an amount that is uniform between the blocks, and the blocks are divided in the order of each stowage block. The second feature is a method of stacking powdery raw materials, which is characterized by stacking each brand in the order of distribution. Hereinafter, the present invention will be explained in detail based on examples thereof. First, from the target composition and quality of the planned sintered ore, the unified target composition of the entire bedding pile shown in Table 1,
The quality structure was determined.

[Table] Next, based on the target ingredients and quality, and based on the ingredients and quality of the existing raw materials and each brand that has been confirmed to arrive at the time of piling, each brand and blending ratio that satisfies the target, ingredients, and quality is determined. Based on this, calculate the amount of each brand that makes up the pile loading weight,
This was allocated to each brand as shown in Table 2, and the allocated amount was stacked in layers using the Siepron method. An example of the stowage plan at this time is shown in Table 2. Based on the target composition and quality of the sintered ore, the target composition and particle size of the entire powdered loading material are determined, and on the other hand, the blending ratio of each brand (the second % column in the table). This mixing ratio and the planned stowage weight of the entire powder stowage material (hereinafter referred to as stowage pile) (Table 2 total column 140,000 tons)
Based on this, set the overall blended weight of each brand as shown in Table 2, and set the stowage pile in a plurality (4 in this example) of predetermined equal weights (the bottom row of Table 2) in the height direction.
35,000 tons) to form stowage blocks, and each stowage block constitutes a homogeneous division of target components and particle size according to the distributed weight by brand shown in Table 2. The actual stowage is carried out in a predetermined block order.
Moreover, the products are stacked so that the stacking order for each brand in each block is at least constant between each stacking block.

【table】

[Table] Thus, each pile was cut out using a double-foil cutting device and sequentially supplied to a sintering factory, and samples were taken using a predetermined sampling device to control the composition and quality of the feedstock. Looking at the data at this time, the monthly average variation in the basicity of the pile was 0.016, which was extremely small compared to 0.025 in the conventional method, and homogenization was further improved. According to the method of the present invention explained above, the ingredients, quality, and composition are uniform for each loading category, so the cut raw material is homogeneous, and the quality of the sintered ore produced from it is uniform and stable, and the blast furnace using it as raw material The present invention has great effects, such as making it possible to operate the furnace with extremely high stability.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the cross-sectional structure of a pile stacked by the SIEPRON method, and FIG. 2 is an explanatory diagram of the cut-out amount distribution by layer when the pile stacked by the SIEPRON method is cut out.

Claims (1)

[Claims] 1 Based on the composition and quality of the sintered ore, determine the target composition and particle size of the powdered loading material, and set the blending ratio of each brand based on this and the components and particle size of each brand of powdered loading material. The combined weight of each brand is calculated based on this mixing ratio and the total weight of the stowage pile plan, and the total weight of the stowage pile plan is divided into a plurality of predetermined equal amounts to form stowage blocks, and the various types mentioned above are calculated. Allocate the brands to each loading block in an amount that is uniform between the blocks, and in the order of each loading block and within the block.
A method for stowing powdery raw materials, characterized in that each brand of the distribution is stowed in order.