A method for building a heap of a high-silica high-alumina ore

Abstract

The application relates to a high furnace iron-making raw material processing technology. A high-silicon high-aluminum ore stacking method provided by the application has the effect of improving the quality of mixed ore. The application can make the distribution of aluminum oxide in the material pile more uniform. In addition, since the problem of uneven distribution of aluminum oxide is solved, the application can introduce more high-silicon high-aluminum ore, thereby reducing the raw material cost of mixed ore.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of steel metallurgy, and in particular to a method for building a pile of ore fines. BACKGROUND

[0002] Domestic and foreign steel enterprises are equipped with large-scale mixing yards. Different varieties of iron ore fines are mixed in the mixing yard and then transported for sintering. The mixed ore is the main iron-containing raw material for sintering, accounting for more than 80% of the new raw material for sintering. The quality of the mixed ore directly affects the yield and quality of the sintered ore. At present, the mixed ore is mixed, neutralized and stacked in the mixing yard with more than 20 kinds of iron-containing raw materials. The composition and particle size of the entire pile are stable and uniform along the long direction of each section, and the composition and particle size fluctuation between the upper and lower piles and between each pile is as small as possible.

[0003] Global iron ore resources are showing a trend of continuous deterioration, and steel enterprises use a large amount of low-quality and low-price ore. High-silicon and high-aluminum iron ore is cheap due to its low iron grade and high mass fraction of aluminum oxide, and is used in large quantities by steel enterprises. Aluminum oxide is one of the main gangue components in iron ore fines and has an important influence on the sintering process. A certain amount of aluminum oxide in iron ore fines can generate silicates containing aluminum oxide and promote the generation of calcium ferrite. However, too high aluminum oxide will increase the viscosity of the liquid phase and reduce the fluidity of the liquid phase, resulting in sintering quasi-particle liquid phase segregation. After high-silicon and high-aluminum ore is mixed and stacked, due to its high mass fraction of aluminum oxide, it will cause uneven distribution of aluminum oxide in the mixed ore and increase the composition fluctuation, which will adversely affect the production of the sintering and ironmaking process. SUMMARY

[0004] The embodiments of the present application provide a stacking method for high-silicon and high-aluminum ore to solve the technical problem of uneven distribution of high-silicon and high-aluminum ore.

[0005] In a first aspect, the embodiments of the present application provide a stacking method for high-silicon and high-aluminum ore, comprising the following steps:

[0006] A plurality of iron-containing materials with known chemical compositions are provided, one of which is high-silicon and high-aluminum ore, and the other of which is high-grade iron ore;

[0007] A plurality of layers are designed, the high-silicon and high-aluminum ore and the high-grade iron ore are concentrated in the same layer, and the ratio of each layer of various iron-containing materials is calculated according to the target chemical composition of the mixed pile.

[0008] The stacking is performed according to the calculated ratio, and the layers are stacked layer by layer to form a pile.

[0009] In some embodiments of the present application, the high-silicon and high-aluminum ore and the high-grade iron ore are concentrated in the outermost layer.

[0010] In some embodiments of the present application, before the outermost layer of the material layer is stacked, the chemical composition of the existing material layer is measured and calculated, and the chemical composition of the outermost layer of the material layer is adjusted so that the overall chemical composition of the material pile formed after the outermost layer of the material layer is stacked is closer to the target chemical composition.

[0011] In some embodiments of the present application, the material pile comprises four material layers.

[0012] In some embodiments of the present application, the material layers are stacked layer by layer by the stacker.

[0013] In some embodiments of the present application, when the material layer containing high-silicon high-aluminum ore is stacked,

[0014] The forward speed of the stacker is 20-24 m / min;

[0015] The reverse speed of the stacker is 30-35 m / min;

[0016] The material flow of the stacker is 1200-1400 t / h.

[0017] In some embodiments of the present application, when the material layer not containing high-silicon high-aluminum ore is stacked,

[0018] The forward speed of the stacker is 16-20 m / min;

[0019] The reverse speed of the stacker is 25-30 m / min;

[0020] The material flow of the stacker is 1400-1700 t / h.

[0021] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0022] The method for building a pile of high-silicon high-aluminum ore provided by the embodiments of the present application can make the chemical composition of the entire material layer approximately match the entire material pile by concentrating the high-silicon high-aluminum ore in one material layer and also concentrating the high-grade iron ore in the material layer, so that the chemical composition of the entire material layer approximately matches the entire material pile; and the high-silicon high-aluminum ore is concentrated in one material layer, which can be mixed more uniformly, and the distribution of aluminum oxide is more uniform; the distribution of aluminum oxide in other material layers is also more uniform because they do not contain high-silicon high-aluminum ore. Therefore, the present application can make the distribution of aluminum oxide in the material pile more uniform. In addition, the present application can introduce more high-silicon high-aluminum ore because it solves the problem of uneven distribution of aluminum oxide, thereby reducing the raw material cost of mixed material. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0025] Figure 1 A flowchart of a high-silicon high-aluminum ore stacking method provided by the embodiments of the present application is shown. DETAILED DESCRIPTION

[0026] The advantages and various effects of the present application will be more clearly presented by the following specific embodiments and examples. Those skilled in the art should understand that these specific embodiments and examples are used to illustrate the present application, not to limit the present application.

[0027] Throughout the specification, unless otherwise specifically indicated, the terms used herein are to be understood as having the meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as generally understood by those skilled in the art to which the present application belongs. If there is a conflict, the present specification takes precedence.

[0028] Unless otherwise specifically indicated, the various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.

[0029] When high-silicon high-aluminum ore is involved in the mixing and stacking, due to its high alumina mass fraction, it will cause uneven distribution of alumina in the mixed ore, increased composition fluctuation, and adverse effects on the production of the sintering and ironmaking process.

[0030] The embodiments of the present application provide a high-silicon high-aluminum ore stacking method to solve the technical problem of uneven distribution of high-silicon high-aluminum ore.

[0031] In a first aspect, referring to Figure 1 The embodiments of the present application provide a high-silicon high-aluminum ore stacking method, comprising the following steps:

[0032] S1: providing a plurality of iron-containing mineral materials with known chemical composition, one of which is high-silicon high-aluminum ore, and the other of which is high-grade iron ore;

[0033] S2: designing a plurality of layers, concentrating high-silicon high-aluminum ore and high-grade iron ore in the same layer, and calculating the ratio of various iron-containing mineral materials in each layer according to the target chemical composition of the mixed ore stack;

[0034] S3: stacking according to the calculated ratio, and stacking the layers one by one to form the stack.

[0035] It is understood by those skilled in the art that the iron-containing mineral materials need to be mixed before sintering. The mixed materials obtained by mixing are generally in the form of a stockpile, which is generally conical. Limited by the processing capacity of the on-site equipment, the stockpile is generally mixed and stacked in batches, and each batch of materials forms a layer. The TFe, SiO2 and Al2O3 contents of each layer are approximately the same. The layer is also called a block in the art.

[0036] It is understood by those skilled in the art that the material composition of each iron-containing mineral material is detected by the mixing plant, and thus the material composition of each iron-containing mineral material is known.

[0037] It is understood by those skilled in the art that high-grade iron ore refers to iron ore with high iron content and low impurity content.

[0038] It is understood by those skilled in the art that the mixed materials used for sintering have certain requirements for chemical composition, i.e., target chemical composition of the mixed materials.

[0039] It is understood by those skilled in the art that the existing stacking method disperses the high-silicon and high-aluminum ore in the entire stockpile. Since the high-silicon and high-aluminum ore itself has a high aluminum content, other iron-containing mineral materials tend to have a low aluminum content. The alumina in the entire stockpile is relatively enriched in the high-silicon and high-aluminum ore. The high-silicon and high-aluminum ore cannot be absolutely uniformly dispersed in the stockpile, and the content of alumina in the area where the high-silicon and high-aluminum ore is relatively concentrated is significantly higher than the overall level of the stockpile, which leads to uneven distribution of alumina in actual production and affects the smooth progress of the sintering and ironmaking process.

[0040] The present application concentrates the high-silicon and high-aluminum ore in one layer and concentrates the high-grade and low-silicon and low-aluminum iron ore in the same layer, so that the chemical composition of the entire layer is approximately matched with that of the entire stockpile. The high-silicon and high-aluminum ore is concentrated in one layer, which increases the amount of high-silicon and high-aluminum ore in the layer and reduces the weighing error caused by small material flow compared to being evenly dispersed in four layers. By increasing the speed of the stacker when building the layer containing high-silicon and high-aluminum ore and increasing the number of layers of the layer, the distribution of alumina in the layer is more uniform. The distribution of alumina in other layers is also more uniform because they do not contain high-silicon and high-aluminum ore. Therefore, the present application can make the alumina in the stockpile more evenly distributed.

[0041] In addition, the present application can introduce a larger amount of high-silicon and high-aluminum ore because it solves the problem of uneven distribution of alumina, thereby reducing the raw material cost of the mixed materials.

[0042] In some embodiments of the present application, the high-silicon and high-aluminum ore and the high-grade iron ore are concentrated in the outermost layer.

[0043] Those skilled in the art can understand that, since the whole stockpile is roughly conical, the thickness of the outer layer is thinner than that of the inner layer if the volume of each layer is roughly the same. The high-silicon high-aluminum ore and high-grade iron ore are concentrated in the outermost layer, and the high-silicon high-aluminum ore is more evenly distributed in the whole stockpile.

[0044] In some embodiments of the present application, before the outermost layer is stacked, the chemical composition of the existing layers is measured, and the chemical composition of the outermost layer is adjusted so that the overall chemical composition of the stockpile formed after the outermost layer is stacked is closer to the target chemical composition. The stockpile can better meet the sintering requirements.

[0045] In some embodiments of the present application, the stockpile includes four layers.

[0046] Those skilled in the art can understand that the stockpile is divided into four layers for stacking, which is a common solution in the art.

[0047] In some embodiments of the present application, in step S3, the layers are stacked layer by layer by the stacker.

[0048] In some embodiments of the present application, when the layer containing high-silicon high-aluminum ore is stacked,

[0049] The forward speed of the stacker is 20-24 m / min;

[0050] The reverse speed of the stacker is 30-35 m / min;

[0051] The flow of the stacker is 1200-1400 t / h.

[0052] Those skilled in the art can understand that by increasing the speed of the stacker and reducing the flow, the number of layers of the high-silicon high-aluminum ore-containing layer is increased, and the distribution of alumina in the layer is more uniform.

[0053] In some embodiments of the present application, when the layer not containing high-silicon high-aluminum ore is stacked,

[0054] The forward speed of the stacker is 18-20 m / min;

[0055] The reverse speed of the stacker is 25-30 m / min;

[0056] The flow of the stacker is 1400-1700 t / h.

[0057] Those skilled in the art can understand that the above technical parameters are conventional technical parameters in the art.

[0058] The present application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and not used to limit the scope of the present application. The experimental methods in the following examples, if no specific conditions are noted, are generally determined according to the national standards. If there is no corresponding national standard, the general international standards, the conventional conditions, or the conditions suggested by the manufacturers are used.

[0059] Examples

[0060] Firstly, the present example provides basic information about various iron-containing mineral materials involved.

[0061] The iron-containing mineral materials involved in the present example are named as follows: C powder, A powder, King, Kuri, New MAC, Jinbao powder, miscellaneous material, high-silicon and high-aluminum mineral.

[0062] The chemical components of the above mineral materials are shown in Table 1.

[0063] TFe (%) SiO2(%) Al2O3(%) Carpow 65.65 2.11 1.3 Alpow 64.56 4.66 1.58 King 57.24 5.82 1.97 Kurri 56.78 6.54 1.75 New MAC 60.45 4.62 2.45 Kingbaw 56.32 8.38 1.75 Gangue 48.05 5.52 1.63 High-silicon high-aluminum ore 56.28 10.65 3.54

[0064] Table 1

[0065] In Table 1, TFe refers to the total iron content.

[0066] The present example also provides a stacking method of high-silicon and high-aluminum mineral, comprising the following steps:

[0067] A stacking plan is made, and the planned values of TFe, SiO2and Al2O3in the stockpile are 58.45%, 5.85% and 2.03%, respectively.

[0068] The mass percentages of each raw material in the stockpile are calculated according to the above plan as follows: C powder 6%, A powder 8%, King 30%, Kuri 13%, New MAC 24%, Jinbao powder 9%, miscellaneous material 5%, and high-silicon and high-aluminum mineral 5%.

[0069] Four layers are designed, and the high-silicon and high-aluminum mineral and the C powder are concentrated in the outermost layer, and the mass percentages of each raw material in the outermost layer are as follows: C powder 10%, A powder 15%, King 20%, Kuri 35%, high-silicon and high-aluminum mineral 20%, and the remaining raw materials are evenly distributed in the other layers according to the batching plan.

[0070] The stacking is performed layer by layer according to the plan, and the stockpile is formed, wherein the flow rate of the outermost layer is 1400 t / h, and the flow rates of the other layers are 1600 t / h.

[0071] After the stockpile is formed, the material rake and the material hopper of the mixing drum sampler are used to deliver the material to the sintering conveyor, and 15 manual samplings are performed on the outer delivery belt, and the test results are shown in Table 2.

[0072] Sample No. TFe (%) SiO2(%) Al203(%) 1 58.47 6.27 2.19 2 58.49 5.89 1.95 3 58.98 6.01 1.93 4 59.13 5.85 1.93 5 59.58 6.16 2.13 6 58.61 5.99 2.02 7 58.61 6.33 2.15 8 58.47 6.7 2.1 9 59.59 6.26 2.11 10 58.52 5.81 1.95 11 59.12 5.97 2.16 12 58.54 5.91 1.96 13 58.46 6.26 1.93 14 59.19 6.29 2.16 15 58.48 5.83 1.91 Average 58.82 6.10 2.04 Standard deviation 0.40 0.24 0.10

[0073] Table 2

[0074] In Table 2, the sampling serial number refers to the serial number of the sample obtained by 15 artificial samplings in the example.

[0075] Comparative Example

[0076] The difference between the present comparative example and the example is only that:

[0077] All raw materials were evenly distributed into four layers, and the flow of all layers was 1600 t / h. The remaining operations were exactly the same as those in Example 1.

[0078] The test results are shown in Table 3.

[0079]

[0080]

[0081] In Table 3, the sampling serial number refers to the serial number of the sample obtained by 15 artificial samplings in the comparative example.

[0082] As can be seen from Table 1 and Table 2, the average values of TFe, SiO2and Al2O3in the example and the comparative example are almost exactly the same because the planned components of the raw materials are exactly the same, which also shows that the actual components of the raw materials in the example and the comparative example are very small. The standard deviation of Al2O3in the example is only 0.10, and the standard deviation in the comparative example is 0.17, and the standard deviation in the example is much lower than that in the comparative example, which shows that the distribution of Al2O3in the example is more uniform. Then, under the condition that the components of the raw materials in the example and the comparative example are basically consistent, the difference between the example and the comparative example is only that the high-silicon high-aluminum ore and the coke breeze are concentrated in the outermost layer in the example, while the comparative example is evenly distributed. This fully shows that the above-mentioned difference of the example is beneficial to the more uniform distribution of Al2O3. At the same time, the standard deviation of SiO2also presents a similar rule, which further proves the effectiveness of the above-mentioned technical means adopted in the example in uniformly distributing Al2O3.

[0083] Various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is only for the convenience and brevity, and should not be understood as a hard limitation on the scope of the present application; therefore, it should be considered that the described range has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, regardless of the range. In addition, whenever a numerical range is indicated in this text, it refers to any cited number (fraction or integer) within the indicated range.

[0084] In this application, the positional words such as "upper" and "lower" are specifically the directions of the drawing surface in the drawings unless otherwise stated. In addition, in the description of the specification, the terms "comprise", "include" and the like mean "including but not limited to". Moreover, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed or inherent to such processes, methods, articles or devices. Without more limitations, the elements defined by the statement "comprise" do not exclude the presence of other identical elements in the processes, methods, articles or devices including the elements. In this text, the relationship terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. In this text, the "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following cases: A exists alone, A and B exist together, and B exists alone. For the association relationship of more than three associated objects described by "and / or", it means that any one of the three associated objects can exist alone, or any at least two of them exist together, for example, for A, and / or B, and / or C, it means that any one of A, B and C exists alone, or any two of them exist together, or all three of them exist together. In this text, "at least one" means one or more, and "multiple" means two or more. "At least one", "at least one of the following" or the like means any combination of the items, including any combination of single or multiple items. For example, "at least one of a, b or c", or "at least one of a, b and c", can mean a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, where a, b and c can be single or multiple.

[0085] The above description is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications of these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A method of stockpiling a high-silica high-alumina ore, characterised by, The method comprises the following steps: providing several iron-containing mineral materials with known chemical compositions, one of which is high-silicon and high-aluminum mineral, and the other is high-grade iron ore; designing multiple layers, and concentrating the high-silicon and high-aluminum mineral and the high-grade iron ore in the same layer, and calculating the proportion of each of the iron-containing mineral materials in each layer according to the target chemical composition of the mixed stockpile; stacking according to the calculated proportion, and stacking the layers to form a stockpile; the high-silicon and high-aluminum mineral and the high-grade iron ore are concentrated in the outermost layer; before stacking the outermost layer, the chemical composition of the existing layers is measured and calculated, and the chemical composition of the outermost layer is adjusted so that the overall chemical composition of the stockpile formed after the outermost layer is stacked is closer to the target chemical composition; the stockpile comprises four layers; the layers are stacked by a stacker; when the layer containing the high-silicon and high-aluminum mineral is stacked, the forward speed of the stacker is 20-24 m / min; the reverse speed of the stacker is 30-35 m / min; the material flow of the stacker is 1200-1400 t / h; when the layer not containing the high-silicon and high-aluminum mineral is stacked, the forward speed of the stacker is 16-20 m / min; the reverse speed of the stacker is 25-30 m / min; the material flow of the stacker is 1400-1700 t / h.

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