Sintering performance evaluation method suitable for superfine iron ore powder

Abstract

The invention relates to a sintering performance evaluation method suitable for superfine iron ore powder, which comprises the following steps: before the iron ore powder is evaluated, sampling is carried out for chemical component analysis and macroscopic particle size detection; respectively carrying out sintering performance index detection on three parts of a normal-temperature overwet zone Ir, a drying preheating zone Id and a sintering high-temperature zone Ic on the iron ore powder, recording data and calculating an iron ore powder sintering conversion coefficient Isinter; calculating a chemical component conversion coefficient alpha iof the iron ore powder according to the detected chemical components of the iron ore powder; recording the iron ore powder price P 'iof, and multiplying the iron ore powder price P' iof by the sintering characteristic value Isinter of the iron ore powder and the chemical component conversion coefficient alpha iof to obtain a final iron ore powder cost performance calculation value Piof; and by comparing the cost performance calculation values Piof of different types of iron ore powder, the iron ore powder with the optimal cost performance is further determined. The sintering performance of the fine iron powder in the actual sintering production simulation process can be more intuitively known, the type of the fine iron powder with high cost performance can be determined through various evaluation index results, and data guidance is provided for production.

Description

Technical Field

[0001] The invention relates to the technical field of iron ore powder sintering performance evaluation, in particular to a sintering performance evaluation method suitable for ultrafine iron ore powder. Background Art

[0002] At present, there are many patents published for the evaluation method of the sintering performance of iron ore powder, and the research is relatively in-depth, and certain research results have been achieved. Most of the technologies evaluate the quality and performance of iron ore used for sintering by detecting the relevant sintering indicators of iron ore in the high-temperature mineralization process, and establish a corresponding relationship between the relevant detection indicators and the sintered ore output, quality, and energy consumption indicators. They have certain scientificity and practicality, and have important guiding significance for sintering production. However, in the actual sintering production process, different types of iron ore powder play different roles in the sintering process, and their sintering characteristics cannot be generalized. In particular, iron ore concentrate, due to its fine particle size and good mixing effect with flux, is often the main material for generating liquid phase, but also because of its fine particle size, its negative impact on the permeability of the material layer is not involved in other types of ore powder. If the sintering effect of the ore powder in the sintering process is predicted and estimated based on the characteristics of the ore powder itself, the relevant research needs to be further improved. Therefore, a sintering performance evaluation method suitable for ultrafine iron ore powder is invented, and the cost-effectiveness evaluation is carried out for the relevant characteristics of iron ore concentrate, which is of great significance for reducing sintering costs and improving sintering quality. Summary of the invention

[0003] The main problem to be solved by the present invention is to more intuitively understand the pros and cons of the sintering performance of iron ore concentrate in the simulated actual sintering production process, and to determine the types of iron ore concentrate with high cost performance through the results of various evaluation indicators to provide data guidance for production.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A sintering performance evaluation method applicable to ultrafine iron ore powder, the method comprising:

[0006] Step 1: Before evaluating the iron ore powder, it is required to take samples for chemical composition analysis and macroscopic particle size detection. The total iron grade TFe>50% and the proportion of ore powder-0.5mm particle size is required to be more than 90%. The chemical composition of the iron ore powder is recorded;

[0007] Step 2: The iron ore powder is subjected to normal temperature wet zone I r 、Drying preheating zone I d , Sintering high temperature zone I c Test the sintering performance indicators of the three parts, record the data and calculate the iron ore powder sintering conversion coefficient I sinter ;

[0008] Step 3: Calculate the conversion coefficient α of the chemical composition of the iron ore powder according to the chemical composition detected by the iron ore powder. iof ;

[0009] Step 4: Record the iron ore powder price P' iof , and the sintering characteristic value I of iron ore powder sinter and chemical composition conversion factor α iof Multiply them together to get the final iron ore powder cost performance calculation value P iof ;

[0010] Step 5: Calculate the cost-effectiveness of different types of iron ore powders iof , and further determine the iron ore powder with the best cost performance.

[0011] As a further technical solution of the present invention, the detection method of chemical composition analysis is element titration, and the detection data are TFe, Fe2O3, FeO, SiO2, MgO, Al2O3, K, Na, and Cl.

[0012] As a further technical solution of the present invention, the macroscopic particle size screening test is divided into four particle size distribution iron ore powder samples: <0.5mm, 0.5-1mm, 1-2mm, 2-3mm, and >3mm.

[0013] As a further technical solution of the present invention, the room temperature over-humid zone sintering performance index test is to select the -0.5mm particle size part of the iron ore powder and place it in a 105°C drying oven for 24 hours, mix it with pure CaO reagent and corundum balls with water, and place it in a drum for granulation to form quasi-particles. After granulation, the quasi-particle size is taken out and sieved.

[0014] As a further technical solution of the present invention, in the normal temperature wet zone sintering performance index detection, the iron ore powder and CaO pure reagent are added in an amount of 400g and 100g respectively, and the corundum ball is added in an amount of 500g±1;

[0015] The normal temperature wet zone sintering performance index test, in order to ensure that the core particle size is sufficient, the particle size of the corundum balls is 3mm;

[0016] The above-mentioned normal temperature over-humidified zone sintering performance index test, the water distribution amount is 120ml, and the actual mixed material moisture content should be 7.8%;

[0017] The normal temperature wet belt sintering performance index test, the drum size is 200mm diameter * 500mm length, the drum speed is 30 revolutions per minute, and the granulation time is 3min;

[0018] The normal temperature wet zone sintering performance index test and the quasi-particle size test are divided into six particle sizes: -0.5mm, 0.5-1mm, 1-3mm, 3-4mm, 4-5mm, and +5mm. The average particle size d of the quasi-particles is calculated according to the particle size distribution. The calculation formula is as follows:

[0019] Formula 1:

[0020] Where d is the average particle size of the quasi-particles, mm; d i is the average size of quasi-particles at different particle sizes, mm, such as 3-4 mm quasi-particles, d i is 3.5; f i is the proportion of quasi-particles at this particle size, %.

[0021] The room temperature super-humid zone sintering performance index I r The calculation formula is:

[0022] Formula 2:

[0023] Among them, I r is the performance index of sintering in the wet zone at room temperature, dimensionless; d is the average particle size of the quasi-particles, mm.

[0024] As a further technical solution of the present invention, the dry preheated zone sintering performance index is to place the iron ore powder in a 105°C drying oven and dry it for 24 hours, fully mix it with pure CaO reagent and add water, and place it in a drum for granulation to form quasi-particles. After granulation, the quasi-particles are taken out and sieved for particle size, and then the quasi-particles are placed in a 500°C muffle furnace, calcined at a constant temperature for 5 minutes, taken out and cooled, and then the quasi-particle size is re-sieved.

[0025] As a further technical solution of the present invention, the dry preheated zone sintering performance index is that the iron ore powder and CaO pure reagent are added in an amount of 400g and 100g respectively, the water content is 77ml, and the actual water content of the mixture should be 7.8%;

[0026] The drying preheat zone sintering performance index is that the drum size is 200mm in diameter and 500mm in length, the drum speed is 30 revolutions per minute, and the granulation time is 3min;

[0027] The dry preheated zone sintering performance index, the quasi-particle size detection by screening, is divided into five particle sizes of -0.5mm, 0.5-1mm, 1-3mm, 3-5mm, +5mm, and the average particle sizes d and d' of the quasi-particles before and after calcination are obtained according to the particle size distribution, and the calculation formula is consistent with Formula 1;

[0028] The drying preheating zone sintering performance index I d The calculation formula is:

[0029] Formula 3:

[0030] As a further technical solution of the present invention, the sintering performance index of the sintering high temperature zone is to conduct high temperature basic performance testing on the iron ore powder to obtain the minimum assimilation temperature T and liquid phase fluidity index I;

[0031] The sintering high temperature zone sintering performance index I c The calculation formula is:

[0032] Formula 4:

[0033] The iron ore powder sintering conversion coefficient I sinter The calculation formula is:

[0034] Formula 5: I sinter =I r ×I d ×I c ;

[0035] As a further technical solution of the present invention, the chemical composition conversion coefficient α of the iron ore powder iof The calculation formula is:

[0036] α iof =w(TFe)-100(w(K)+w(Na)+w(Cl)).

[0037] As a further technical solution of the present invention, the final iron ore powder cost performance calculation value P iof The calculation formula is:

[0038] P iof =P′ iof / (I sinter +α iof ).

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention proposes a sintering performance evaluation method suitable only for iron ore concentrate, which detects the characteristics of the three parts of the normal temperature over-humidification zone, the drying preheating zone, and the sintering high temperature zone of the ore powder to be evaluated according to its role in the sintering process, proposes corresponding indicators, obtains the total value of the sintering characteristics after data processing, and evaluates the cost performance of the iron ore concentrate according to the total value of the sintering characteristics and its own price. This method can take into account all the processes that the ore powder undergoes during the sintering process from granulation to sintering, and can evaluate the cost performance of the iron ore powder from the entire sintering process, so as to more intuitively understand the impact of different types of iron ore concentrate on actual sintering production and the benefits it brings, which is of great significance for enterprises to select high-quality and cost-effective iron ore powder raw materials, reduce sintering costs, and improve the quality of sintered finished ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The present invention is a process flow chart of a sintering performance evaluation method suitable for ultrafine iron ore powder. DETAILED DESCRIPTION

[0041] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] like Figure 1 As shown, an embodiment of the present invention provides a sintering performance evaluation method applicable to ultrafine iron ore powder, the method comprising:

[0043] Step 1: Before evaluating the iron ore powder, it is required to take samples for chemical composition analysis and macroscopic particle size detection. The total iron grade TFe>50% and the proportion of ore powder-0.5mm particle size is required to be more than 90%. The chemical composition of the iron ore powder is recorded;

[0044] Step 2: The iron ore powder is subjected to normal temperature wet zone I r 、Drying preheating zone I d , Sintering high temperature zone I c Test the sintering performance indicators of the three parts, record the data and calculate the iron ore powder sintering conversion coefficient I sinter ;

[0045] Step 3: Calculate the conversion coefficient α of the chemical composition of the iron ore powder according to the chemical composition detected by the iron ore powder. iof ;

[0046] Step 4: Record the iron ore powder price P' iof , and the sintering characteristic value I of iron ore powder sinter and chemical composition conversion factor α iof Multiply them together to get the final iron ore powder cost performance calculation value P iof ;

[0047] Step 5: Calculate the cost-effectiveness of different types of iron ore powders iof , and further determine the iron ore powder with the best cost performance.

[0048] In this embodiment, chemical composition analysis, macroscopic particle size detection, mixing and granulation, drying and roasting, high temperature basic property detection and cost performance calculation are performed on three kinds of sintered iron concentrates according to the above steps. The chemical composition and particle size composition of the experimental iron concentrates are shown in Table 1:

[0049] Table 1 Chemical composition and particle size composition of iron ore concentrate

[0050]

[0051] In this embodiment, the detection method of the chemical composition analysis is element titration, and the detection data are TFe, Fe2O3, FeO, SiO2, MgO, Al2O3, K, Na, and Cl.

[0052] In this embodiment, the macroscopic particle size screening test is performed to divide the iron ore powder samples into four particle size distributions of <0.5 mm, 0.5-1 mm, 1-2 mm, 2-3 mm, and >3 mm.

[0053] In the present embodiment, the room temperature over-humidification zone sintering performance index test is to select the -0.5 mm particle size part of the iron ore powder and place it in a 105°C drying oven for 24 hours, mix it with pure CaO reagent and corundum balls with water, and place it in a drum for granulation to form quasi-particles. After granulation, the quasi-particles are taken out and sieved for particle size.

[0054] In the present embodiment, the normal temperature wet zone sintering performance index test, the iron ore powder and CaO pure reagent are added in an amount of 400g and 100g respectively, and the corundum ball is added in an amount of 500g±1;

[0055] The normal temperature wet zone sintering performance index test, in order to ensure that the core particle size is sufficient, the particle size of the corundum balls is 3mm;

[0056] The above-mentioned normal temperature over-humidified zone sintering performance index test, the water distribution amount is 120ml, and the actual mixed material moisture content should be 7.8%;

[0057] The normal temperature wet belt sintering performance index test, the drum size is 200mm diameter * 500mm length, the drum speed is 30 revolutions per minute, and the granulation time is 3min;

[0058] The normal temperature wet zone sintering performance index test and the quasi-particle size test are divided into six particle sizes: -0.5mm, 0.5-1mm, 1-3mm, 3-4mm, 4-5mm, and +5mm. The average particle size d of the quasi-particles is calculated according to the particle size distribution. The calculation formula is as follows:

[0059] Formula 1:

[0060] Where d is the average particle size of the quasi-particles, mm; d i is the average size of quasi-particles at different particle sizes, mm, such as 3-4 mm quasi-particles, d i is 3.5; f i is the proportion of quasi-particles at this particle size, %.

[0061] The room temperature super-humid zone sintering performance index I r The calculation formula is:

[0062] Formula 2:

[0063] Among them, I r is the performance index of sintering in the wet zone at room temperature, dimensionless; d is the average particle size of the quasi-particles, mm.

[0064] In this embodiment, the dry preheated zone sintering performance index is to place the iron ore powder in a 105°C drying oven and dry it for 24 hours, fully mix it with pure CaO reagent and add water, and place it in a drum for granulation to form quasi-particles. After granulation, take out the quasi-particles and screen the particle size, then place the quasi-particles in a 500°C muffle furnace, roast them at a constant temperature for 5 minutes, take them out and cool them, and then re-screen the quasi-particle size.

[0065] In this embodiment, the dry preheated zone sintering performance index is that the iron ore powder and CaO pure reagent are added in amounts of 400g and 100g respectively, the water content is 77ml, and the actual water content of the mixture should be 7.8%;

[0066] The drying preheat zone sintering performance index is that the drum size is 200mm in diameter and 500mm in length, the drum speed is 30 revolutions per minute, and the granulation time is 3min;

[0067] The dry preheated zone sintering performance index, the quasi-particle size detection by screening, is divided into five particle sizes of -0.5mm, 0.5-1mm, 1-3mm, 3-5mm, +5mm, and the average particle sizes d and d' of the quasi-particles before and after calcination are obtained according to the particle size distribution, and the calculation formula is consistent with Formula 1;

[0068] The drying preheating zone sintering performance index I d The calculation formula is:

[0069] Formula 3:

[0070] In this embodiment, the sintering high temperature zone sintering performance index is to perform high temperature basic performance testing on the iron ore powder to obtain the minimum assimilation temperature T and liquid phase fluidity index I;

[0071] The sintering high temperature zone sintering performance index I c The calculation formula is:

[0072] Formula 4:

[0073] The iron ore powder sintering conversion coefficient I sinter The calculation formula is:

[0074] Formula 5: I sinter =I r ×I d ×I c ;

[0075] In this embodiment, the chemical composition conversion coefficient of the iron ore powder is α iof The calculation formula is:

[0076] α iof =w(TFe)-100(w(K)+w(NA)+w(Cl)).

[0077] In this embodiment, the final iron ore powder cost performance calculation value P iof The calculation formula is:

[0078] P iof =P′ iof / (I sinter +α iof ).

[0079] The calculation results of the performance indicators of the three iron concentrates are shown in Table 2. Due to the different origins of the three iron concentrates, the three sintering performance indicators vary greatly: the granulation performance of the three iron concentrates is basically the same under room temperature conditions, all above 0.70, so the air permeability of the sintering room temperature over-humidification zone is less affected; from the test results, it can be seen that the iron concentrate A is more likely to burst in the drying and preheating section of about 500°C, resulting in a significant decrease in the quasi-particle size, so its drying and preheating zone sintering performance index I d The high temperature basic properties are relatively poor, so the overall calculation of the iron ore powder sintering conversion coefficient I sinter The three sintering characteristic indicators of iron ore concentrate B and iron ore concentrate C are basically similar, but the overall indicator of iron ore concentrate C is better, so the overall calculation of iron ore powder sintering conversion coefficient I sinter maximum.

[0080] Table 2 Calculation results of iron ore concentrate performance indicators

[0081]

[0082] The results of the conversion coefficients of the chemical composition of the three iron ore concentrates and the calculated cost performance of the iron ore powder are shown in Table 3, where P iofThe lower the value, the higher the cost performance of iron ore powder. As can be seen from the table, although iron ore concentrate A has a higher iron grade, its overall sintering characteristics are the worst, and its price is relatively high. Therefore, from the calculation results, it is the iron ore concentrate with the lowest cost performance; although the sintering characteristics of iron ore concentrate C are higher than those of iron ore concentrate B, its chemical composition contains a large amount of elements such as K, Na, and Cl, which have a huge impact on sintering equipment. Therefore, the chemical composition conversion coefficient of iron ore powder is low, and its price is the highest. Therefore, its cost performance is lower than that of iron ore concentrate B and higher than that of iron ore concentrate C; while iron ore concentrate B has good sintering characteristics, only the iron grade is relatively low, and its price is also the lowest among the three ore powders, so it has the highest cost performance. From the perspective of price, the three ore powders are ranked as: C>A>B, and the final calculation results show that the cost performance ranking of the three ore powders should be: B>C>A, so iron ore concentrate B should be selected as the sintering raw material purchase.

[0083] Table 3 Conversion coefficient of chemical composition of iron ore powder and calculated value of cost performance of iron ore powder

[0084]

[0085] It should be noted that, in this article, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0086] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for evaluating the sintering performance of ultrafine iron ore powder, characterized in that: The method comprises: Step 1: Before evaluating the iron ore powder, it is required to take samples for chemical composition analysis and macroscopic particle size detection. The total iron grade TFe>50% and the proportion of ore powder-0.5mm particle size is required to be more than 90%. The chemical composition of the iron ore powder is recorded; Step 2: The iron ore powder is subjected to normal temperature wet zone I r 、Drying preheating zone I d , Sintering high temperature zone I c Test the sintering performance indicators of the three parts, record the data and calculate the iron ore powder sintering conversion coefficient I sinter ; Step 3: Calculate the conversion coefficient α of the chemical composition of the iron ore powder according to the chemical composition detected by the iron ore powder. iof ; Step 4: Record the iron ore powder price P' iof , and the sintering characteristic value I of iron ore powder sinter and chemical composition conversion factor α iof Multiply them together to get the final iron ore powder cost performance calculation value P iof ; Step 5: Calculate the cost-effectiveness of different types of iron ore powders iof , and further determine the iron ore powder with the best cost performance.

2. A sintering performance evaluation method for ultrafine iron ore powder according to claim 1, characterized in that: The detection method of the chemical composition analysis is element titration, and the detection data include TFe, Fe2O3, FeO, SiO2, MgO, Al2O3, K, Na, and Cl.

3. The sintering performance evaluation method for ultrafine iron ore powder according to claim 1, characterized in that: The macroscopic particle size screening test is divided into four particle size distribution iron ore powder samples: <0.5mm, 0.5-1mm, 1-2mm, 2-3mm, and >3mm.

4. The sintering performance evaluation method for ultrafine iron ore powder according to claim 1, characterized in that: The normal temperature over-humid zone sintering performance index test is to select the -0.5mm particle size part of the iron ore powder and place it in a 105°C drying oven for 23-25 ​​hours, mix it with pure CaO reagent and corundum balls with water, and place it in a drum for granulation to form quasi-particles. After granulation, the quasi-particle size is taken out and sieved.

5. A sintering performance evaluation method for ultrafine iron ore powder according to claim 4, characterized in that: In the normal temperature wet zone sintering performance index test, the iron ore powder and CaO pure reagent are added in an amount of 400g and 100g respectively, and the corundum ball is added in an amount of 500g±1; The performance index test of the room temperature wet zone sintering shows that the particle size of the corundum balls is 3mm. The above-mentioned normal temperature over-humidified zone sintering performance index test, the water distribution amount is 120ml, and the actual mixed material moisture content should be 7.8%; The normal temperature wet belt sintering performance index test, the drum size is 200mm diameter * 500mm length, the drum speed is 30 revolutions per minute, and the granulation time is 3min; The normal temperature wet zone sintering performance index test and the quasi-particle size test are divided into six particle sizes: -0.5mm, 0.5-1mm, 1-3mm, 3-4mm, 4-5mm, and +5mm. The average particle size d of the quasi-particles is calculated according to the particle size distribution. The calculation formula is as follows: Formula 1: Where d is the average particle size of the quasi-particles; d i is the average particle size of quasi-particles at different particle sizes; f i is the proportion of quasi-particles at this particle size. The room temperature super-humid zone sintering performance index I r The calculation formula is: Formula 2: Among them, I r is the performance index of sintering in the wet zone at room temperature, dimensionless; d is the average particle size of the quasi-particles, mm.

6. A sintering performance evaluation method for ultrafine iron ore powder according to claim 5, characterized in that: The dry preheated zone sintering performance index is to place the iron ore powder in a 105°C drying oven for 24 hours, fully mix it with pure CaO reagent and add water, and place it in a drum for granulation to form quasi-particles. After granulation, take out the quasi-particles and screen the particle size, then place the quasi-particles in a 500°C muffle furnace, roast them at a constant temperature for 5 minutes, take them out and cool them, and then re-screen the quasi-particle size.

7. A sintering performance evaluation method for ultrafine iron ore powder according to claim 6, characterized in that: The dry preheated zone sintering performance index is that the iron ore powder and CaO pure reagent are added in amounts of 400g and 100g respectively, the water content is 77ml, and the actual water content of the mixture should be 7.8%; The drying preheat zone sintering performance index is that the drum size is 200mm in diameter and 500mm in length, the drum speed is 30 revolutions per minute, and the granulation time is 3min; The dry preheated zone sintering performance index, the quasi-particle size detection by screening, is divided into five particle sizes of -0.5mm, 0.5-1mm, 1-3mm, 3-5mm, +5mm, and the average particle sizes d and d' of the quasi-particles before and after calcination are obtained according to the particle size distribution, and the calculation formula is consistent with Formula 1; The drying preheating zone sintering performance index I d The calculation formula is: Formula 3:

8. The sintering performance evaluation method for ultrafine iron ore powder according to claim 1, characterized in that: The sintering performance index of the sintering high temperature zone is to test the basic performance of the iron ore powder at high temperature to obtain the minimum assimilation temperature T and the liquid phase fluidity index I; The sintering high temperature zone sintering performance index I c The calculation formula is: Formula 4: The iron ore powder sintering conversion coefficient I sinter The calculation formula is: Formula 5: I sinter =I r ×I d ×I c。 9. The sintering performance evaluation method for ultrafine iron ore powder according to claim 1, characterized in that: The iron ore powder chemical composition conversion coefficient α iof The calculation formula is: α iof =w(TFe)-100(w(K)+w(Na)+w(Cl))。 10. The sintering performance evaluation method for ultrafine iron ore powder according to claim 1, characterized in that: The final iron ore powder cost performance calculation value P iof The calculation formula is: P iof =P′ iof / (I sinter +a iof )。

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