An evaluation method for iron ore sintering burdening scheme based on comprehensive sintering binding index

Abstract

The present invention discloses an evaluation method for iron ore sintering ore blending scheme based on comprehensive sintering bonding index. The evaluation method for iron ore sintering ore blending scheme based on comprehensive sintering bonding index includes the following steps: measuring the particle size composition of single ore, respectively measuring the bonded index and the bonding index of the coarse and fine particle sizes of single ore, calculating the sintering bonding index of the ore blending scheme, and optimizing the ore blending scheme. This method has a simple test process, high reliability of calculation results, can quickly obtain the sintering comprehensive bonding index under different ore blending schemes, and guides the ore blending in sintering production.

Description

Technical Field

[0001] The present invention belongs to the technical field of sintering in blast furnace ironmaking, and particularly relates to a method for evaluating an iron ore sintering ore blending scheme based on a comprehensive sintering bonding index. Background Art

[0002] Sintering is one of the pretreatment processes for fine iron ore before entering the furnace, and the quality of sintered ore seriously affects the production efficiency of blast furnaces. Sintering ore blending is an important means to control the quality of sintered ore. Through reasonable ore blending, not only can the quality of sintered ore be improved, but also cost can be saved and consumption reduced, and the range of sintering raw material resources can be expanded.

[0003] In the early stage, the optimization of sintering ore blending was mainly carried out through sintering pot tests. The optimal ore blending scheme was determined through a large number of test results. When there was a lack of research basis, the sintering test played an important role in exploring the optimized ore blending scheme. However, this method has a large amount of test work, a long cycle, and new sintering tests are required every time the raw materials change.

[0004] Wu Shengli et al. proposed to optimize ore blending based on the high-temperature properties of iron ores by measuring the high-temperature properties of single iron ores, such as assimilation, liquid-phase fluidity, self-strength of the bonding phase, calcium ferrite formation characteristics, and continuous crystal consolidation strength. Based on this method, the sintering properties of each single ore can be understood, providing a direction for optimizing ore blending and reducing the blindness of ore blending to a certain extent.

[0005] Fan Xiaohui et al. established a sintering ore blending model using support vector machines to predict the sintering performance of different ore blending schemes and obtain an optimized ore blending scheme by measuring parameters such as the liquid-phase formation characteristics and fluidity of single iron ores and the liquid-phase formation amount, and combining the test results of sintering pot tests for different ore blending schemes. The main problem with this method is that a large amount of ore blending test data is required to ensure the accuracy of the model, and when adding new ore types, the sintering test results need to be supplemented to update the model.

[0006] The essence of sintering is that part of the iron ore reacts with the flux to generate a liquid phase, which bonds and wraps the unmolten iron ore particles. After the liquid phase solidifies, a sintered ore with strength is formed. In the actual sintering process, the liquid phase is mainly generated by the reaction of fine-grained iron ore and the flux, while most of the coarse-grained iron ore is not melted and is bonded by the liquid phase. The roles of large-grained and small-grained iron ores are inconsistent. Therefore, it is necessary to consider their sintering properties separately.

[0007] Current optimization ore blending technologies do not separately consider the differences in the roles of large-grained and small-grained iron ores during the sintering process. Therefore, it is necessary to propose a new optimized ore blending method based on the bonding ability of fine-grained iron ore and the bonded ability of coarse-grained iron ore to guide the actual sintering production. Summary of the Invention

[0008] The present invention is a method for evaluating the iron ore sintering ore blending scheme based on the comprehensive sintering bond index. In the case of introducing standard powder, the bond index of the standard powder, the bond index of the large-particle iron ore, and the sintering index of the fine-particle iron ore are measured respectively, and the above properties are considered comprehensively to conduct an index analysis on the product properties of different sintering ore blending schemes, so as to obtain a more optimized sintering ore blending scheme.

[0009] The present invention is a method for evaluating the iron ore sintering ore blending scheme based on the comprehensive sintering bond index, including the following steps:

[0010] Step 1

[0011] Obtain the bond index BI of the 3-mm sized ore powder in the i-th single ore i and obtain the bond index BI of the standard powder s , and obtain the bond index CI of the standard powder lump and the +3-mm sized ore particles in the i-th single ore powder i ;

[0012] Step 2

[0013] Calculate the sintering bond index based on the sintering ore blending scheme and the properties of the measured single ores; the calculation formula is:

[0014]

[0015] In the formula: CSBI is the comprehensive sintering bond index;

[0016] α i is the content of the -3-mm particles of the i-th single ore;

[0017] β i is the mass percentage ratio of the i-th single ore in the mixed ore, that is, the mass percentage of the dry i-th single ore in the dry mixed ore in the sintering ore blending scheme;

[0018] The ore blending scheme includes selecting n single ores for mutual blending; n is a positive integer greater than or equal to 1;

[0019] Step 3 Selection of the optimized ore blending scheme

[0020] Select the corresponding optimized ore blending scheme according to the principle that the CSBI value is greater than 1 and the larger the better.

[0021] The present invention is a method for evaluating the iron ore sintering ore blending scheme based on the comprehensive sintering bond index, and the step 1 includes the following steps:

[0022] Step 1-1 Screening of single ores

[0023] Screen the i-th single ore to screen out the ore powder with a particle size of -3 mm and the ore particles with a particle size of +3 mm, and record the percentage α of the mass of the -3 mm particles in the i-th single ore accounting for the total mass of the i-th single ore i , that is, α i is the mass percentage of the -3 mm part of the i-th single ore in the mass of the i-th single ore; the i is an integer greater than or equal to 1;

[0024] Step 1-2 Single ore batching and forming

[0025] Mix the -3 mm sized ore powder of the i-th single ore with flux and water evenly, press and form, and then dry to obtain the green compact of the -3 mm sized ore powder of the i-th single ore; it is used to measure the bonding index BI of the fine particle size of the i-th single ore i ;

[0026] Step 1-3 Standard powder batching and forming

[0027] Prepare the standard powder with pure reagents and mix it evenly with water, press and form, and then dry to obtain the standard powder block; the standard powder block is used to measure the bonding index BI of the standard powder s , and is also used to measure the bonding index CI of the standard powder block and the +3 mm sized ore particles (coarse particle size) in the i-th single ore powder i .

[0028] The present invention is a method for evaluating the ore blending scheme for iron ore sintering based on the comprehensive sintering bonding index,

[0029] The method for measuring the bonding index BI of the -3 mm ore powder of the i-th single ore is as follows: Spread corundum balls in a corundum container, place the green compact of the -3 mm sized ore powder of the i-th single ore with a mass of m i on the surface of the corundum balls, carry out simulated sintering using the set heating rate system and atmosphere control system, weigh the minerals adhered to the corundum balls together after sintering, and record it as m i0 ; Calculate the single ore bonding index BI using formula (1) i1 ; i ;

[0030] BI i =(m i1 -m i0 ) / m i0 (1)

[0031] When applied industrially, the set heating rate system and atmosphere control system are carried out according to the corresponding parameters of the existing sintering process. During the development of the technology of the present invention, a sintering simulation device as shown in Figure 1 is used to carry out simulated sintering according to the sintering heating rate system and atmosphere control system (see Figure 2 ), and measure its bonding index BI i .

[0032] In the process of measuring the bonding index BI of the i-th single ore - 3mm ore powder i during the process, there will be some corundum balls that are not adhered with minerals; the mass of this part of corundum balls is not included in m i1 .

[0033] When applied industrially, the mass of the green compact of the i-th single ore - 3mm particle size ore powder to be placed on the surface of the corundum balls is defined as A; then the mass of the corundum balls placed in the corundum container is greater than or equal to 10A, preferably 10 - 20A. As a preference, the diameter of the corundum balls is 3 - 5mm. As a further preference, the diameter of the corundum balls is 3 - 3.5mm.

[0034] The present invention is a method for evaluating the ore blending scheme for iron ore sintering based on the comprehensive sintering bonding index

[0035] Measuring the bonding index BI of the standard powder s : Cover the corundum balls in the corundum container, place the standard powder compact with a mass of m s0 on the surface of the corundum balls, perform simulated sintering using the set heating system and atmosphere control system, and after sintering, weigh the standard objects adhered with corundum balls together, and record it as m s2 ; Calculate the bonding index BI of the standard powder using formula (2) s ;

[0036] BI s = (m s2 -m s0 ) / m s0 (2)

[0037] The above standard object is the product obtained after heating and melting the standard powder compact. The mass of the used corundum balls is greater than or equal to 10m s0 ; The diameter of the corundum balls is 3 - 5mm. As a further preference, it is completely consistent with the corresponding parameters used when measuring the bonding index BI of the i-th single ore - 3mm ore powder i .

[0038] In the process of measuring the bonding index BI of the standard powder s during the process, there will be some corundum balls that are not adhered with the standard object; the mass of this part of corundum balls is not included in m s2 .

[0039] The present invention is a method for evaluating the ore blending scheme for iron ore sintering based on the comprehensive sintering bonding index

[0040] Measuring the bonding index CI of the +3mm ore particles in the i-th single ore i ; Cover the +3mm ore particles of the i-th single ore in the corundum container, and place the mass of m si0Place the standard flour sample on the surface of the +3mm ore particles of the i-th single ore, and perform simulated sintering according to the sintering heating system and the atmosphere control system. Weigh the total mass of the used standard flour sample and the +3mm ore particles of the i-th single ore bonded by the used standard flour sample, and record it as m si1 ; Calculate the bonding index CI of the +3mm ore particles in the i-th single ore using formula (3) i ; Measure the bonding index CI of the +3mm ore particles in the i-th single ore i When measuring, the mass of the +3mm ore particles of the i-th single ore used should be greater than or equal to 5m si0 ; Preferably, it is greater than or equal to 10m si0 ; Further preferably, it is 10m si0 ~25m si0 ;

[0041] CI i = (m si1 -m si0 ) / m si0 (3)

[0042] In the present invention, when measuring the bonding index CI of the +3mm ore particles in the i-th single ore i , it is necessary to ensure that the mass of the +3mm ore particles of the i-th single ore used is greater than 5m si0 , otherwise it will lead to the problem of data distortion. In this step, a part of the +3mm ore particles of the i-th single ore used will not be bonded by the standard flour sample.

[0043] As a preferred solution: In a method for evaluating an iron ore sintering ore blending scheme based on the comprehensive sintering bonding index of the present invention, the flux is selected from at least one of calcium oxide, calcium hydroxide, calcium carbonate, magnesium carbonate reagents, or slaked lime, limestone, dolomite, serpentine, magnesite used in industrial production;

[0044] The dosage is: adding a flux of 10-30% of the mass of the -3mm particle size ore powder of the i-th single ore.

[0045] As a preferred solution: In a method for evaluating an iron ore sintering ore blending scheme based on the comprehensive sintering bonding index of the present invention, water is added in a ratio of 0.8-1.2 mL of water per 10 g of ore powder. That is, the -3mm particle size ore powder of the i-th single ore is mixed evenly with the flux and water, pressed into shape and dried to obtain a green compact of the -3mm particle size ore powder of the i-th single ore; 0.8-1.2 mL of water is used for 10 g of the -3mm particle size ore powder of the i-th single ore. Similarly, a standard powder is prepared with pure reagents and mixed evenly with water, pressed into shape and dried to obtain a standard powder block; that is, 0.8-1.2 mL of water is used for 10 g of the standard powder.

[0046] As a preferred embodiment: For an evaluation method of an iron ore sintering burden distribution scheme based on the comprehensive sintering bonding index of the present invention, the forming pressure is 2 - 20 MPa, and the sample size is a φ10 * 5 mm cylinder.

[0047] As a preferred embodiment: For an evaluation method of an iron ore sintering burden distribution scheme based on the comprehensive sintering bonding index of the present invention, the composition range of the standard powder is between 60 - 85 wt% Fe2O3 - 4 - 6 wt% SiO2 - 10 - 20 wt% CaO - 0 - 5 wt% MgO - 0 - 7 wt% Al2O3. When applied industrially, as a reference material for a system, its specific composition is set according to the composition range of the -3 mm part in the current sintering production or the expected sintering mixture.

[0048] As a preferred embodiment: For an evaluation method of an iron ore sintering burden distribution scheme based on the comprehensive sintering bonding index of the present invention, when sintering production has not been carried out or its value cannot be determined, according to the general requirements of iron ore sintering production, the composition of the standard powder can be set as 72 wt% Fe2O3 - 5 wt% SiO2 - 20 wt% CaO - 1 wt% MgO - 2 wt% Al2O3 and 77 wt% Fe2O3 - 5 wt% SiO2 - 15 wt% CaO - 1 wt% MgO - 2 wt% Al2O3 respectively.

[0049] As a preferred embodiment: For an evaluation method of an iron ore sintering burden distribution scheme based on the comprehensive sintering bonding index of the present invention, the testing equipment used includes a vertical furnace equipped with a sample injection guide rail and an atmosphere control system. The control range of the sample heating and cooling rate is 0 - 30 °C / s, preferably 0 - 20 °C / s. The vertical tube furnace is more conducive to controlling the furnace atmosphere. The vertical furnace is provided with a vertical guide rail, a temperature measuring device, an air inlet system, and a sample carrier platform; the sample carrier platform is horizontally arranged and connected to the guide rail; the guide rail is connected to a driving device; under the drive of the driving device, the sample carrier platform can be raised or lowered. A corundum container is placed on the carrier platform, and 3 mm corundum balls or +3 mm iron ore particles are laid in the corundum container.

[0050] As a further preferred embodiment: For an evaluation method of an iron ore sintering burden distribution scheme based on the comprehensive sintering bonding index of the present invention, it is necessary to determine the bonding index BI of the i-th single ore -3 mm ore powder, the bonding index BI of the standard powder, and the bonding index CI of the +3 mm ore particles under different flux contents. The flux content range is set according to the fine particle size ratio and sintering basicity requirements under different burden distribution schemes. The lower and upper limits (c(CaO), c(CaO)) of the flux content within the measurement range, the bonding index BI, and the bonding index CI i , the bonding index BI of the standard powder s and the bonding index CI of the +3 mm ore particles i , the flux content range is set according to the fine particle size ratio and sintering basicity requirements under different burden distribution schemes. The lower and upper limits (c(CaO) l , c(CaO) h ) of the bonding index BI and the bonding index CI i of the measured range i, namely BI il , BI ih , CI il and CI ih . The above measurement results can be used to calculate the bonding index BI i under the actual flux content c(CaO) in the -3mm particle size fraction for different ore blending schemes i . And the bonding index CI of the +3mm particle size fraction of ore particles when the standard powder acts with the +3mm particle size fraction of ore particles under the corresponding flux content.

[0051] γ = Σα i β i (4)

[0052] In the formula: γ is the content of -3mm in the blended material obtained from the ore blending scheme;

[0053] α i is the mass percentage of -3mm ore particles in the i-th single ore;

[0054] In the ore blending scheme, β i is the mass percentage of the i-th single ore in the ore blending scheme;

[0055] c(CaO) = R·c(SiO2) / γ (5)

[0056] In the formula: c(CaO) is the CaO content used when calculating the single ore BI i , BI s , CI i of different ore blending schemes;

[0057] R is the binary basicity in the ore blending scheme;

[0058] c(SiO2) is the SiO2 content in the ore blending scheme.

[0059] As a preferred scheme: An evaluation method for an iron ore sintering ore blending scheme based on the comprehensive sintering bonding index of the present invention can set the lower limit and upper limit of the flux content to c(CaO) l = 15%, c(CaO) h = 20% according to the general requirements of iron ore sintering production. When a new sintering plant has not yet carried out sintering production or ore blending tests, the lower limit and upper limit of the flux content can also be set to c(CaO) l = 15%, c(CaO) h = 20%; this is because most current sintering plants mainly use imported ores and add concentrate powders for sintering production. The proportion of the -3mm part in the ore is 50 - 70%, and the CaO content in the -3mm part of the sintering material is between 15 - 20%.

[0060] The content of flux c(CaO) in the -3mm fine particle size fraction, as an important indicator of the sintering ore-forming environment, varies under different ore blending schemes. For each ore blending scheme, the BI of the single ore for c(CaO) is tested i 、BI s 、CI i , which will increase the number of experiments. Therefore, determining the BI of the single ore within the upper and lower limits of a reasonable range of c(CaO) i 、BI s 、CI i , and calculating the flux content c(CaO) falling within this range is an efficient and fast method. Therefore, as a further optimized solution: In a method for evaluating an iron ore sintering ore blending scheme based on the comprehensive sintering bond index of the present invention, in order to further reduce the number of experiments, the present invention attempts to obtain corresponding parameters equivalent to the added amount of flux (calculated as calcium oxide) in the ore blending scheme by interpolation calculation, such as:

[0061] When it is necessary to obtain the bond index BI of the -3mm ore powder of the i-th single ore at different flux contents in the ore blending scheme i计算 ; select the lower limit and upper limit of the flux content c(CaO) in the ore blending scheme l 、c(CaO) h 、and obtain BI through formula (1) and the corresponding test method ih 、BI il ; where BI ih 、BI il are the bond indices of the -3mm part of the i-th single ore at flux contents of c(CaO) l 、c(CaO) h respectively; then calculate according to formula (6):

[0062]

[0063] c(CaO) in formula 6 is calculated according to formula 5

[0064] When it is necessary to obtain the bond index BI of the standard powder at different flux contents in the ore blending scheme s计算 ; select the lower limit and upper limit of the flux content c(CaO) l 、c(CaO) h 、and obtain BI through formula (2) and the corresponding test method sh 、BI sl ; BI sh 、BI sl are the bond indices of the standard powder at flux contents of c(CaO) l, c(CaO) h The caking index under; then calculate BI according to formula (7) s计算 ;

[0065]

[0066] The c(CaO) in formula 7 is obtained according to formula 5.

[0067] In the present invention, two kinds of standard powders are selected. One is 72wt% Fe2O3 - 5wt% SiO2 - 20wt% CaO - 1wt% MgO - 2wt% Al2O3, and the other is 77wt% Fe2O3 - 5wt% SiO2 - 15wt% CaO - 1wt% MgO - 2wt% Al2O3.

[0068] It is necessary to obtain the caking index CI of the i-th single ore + 3mm ore powder under different flux contents in the ore blending scheme i计算 When; select the lower limit and upper limit of the flux content c(CaO) l , c(CaO) h (that is, the upper limit value and lower limit value of calcium oxide introduced in the standard powder), obtain CI through formula (3) and the corresponding test method ih , CI il ; where BI ih , BI il are the comprehensive caking indexes of the +3mm part of the i-th single ore at the flux contents of c(CaO) l , c(CaO) h respectively; then calculate CI according to formula (8) i计算 :

[0069]

[0070] In formulas 6, 7, and 8:

[0071] BI i计算 is the calculated value of the caking index of the -3mm part of the i-th single ore;

[0072] BI s计算 is the calculated value of the caking index of the standard powder;

[0073] CI i计算 is the calculated value of the caking index of the +3mm part of the i-th single ore;

[0074] BI ih , BI il are the caking indexes of the -3mm ore particles of the i-th single ore at the flux contents of c(CaO) l , c(CaO) h respectively;

[0075] BI sh 、 BI sl are the Roga indices of standard flour at flux contents of c(CaO) l 、 c(CaO) h respectively;

[0076] CI ih 、 CI il are the comprehensive adhesion indices of +3mm ore particles of the i-th single ore at flux contents of c(CaO) l 、 c(CaO) h respectively;

[0077]

[0078] In the formula: CSBI is the comprehensive sintering adhesion index;

[0079] α i is the mass percentage of -3mm ore particles in the i-th single ore;

[0080] β i is the mass percentage of the i-th single ore in the ore blending scheme.

[0081] The BI in Formula 9 i can be the measured value or the BI i计算 value. To reduce the number of experiments, it is preferably the BI i计算 ; The BI s can be the measured value or the BI s计算 value. To reduce the number of experiments, it is preferably the BI s计算 value; The CI i can be the measured value or the CI i计算 value. To reduce the number of experiments, it is preferably the CI i计算 value.

[0082] The present invention first attempts to introduce standard flour; the purpose of introducing standard flour is to reduce the experimental workload and achieve the feasibility and expandability of this method in production practice. As Figure 3Shown as follows: Before introducing standard flour and corundum balls, it is necessary to separately investigate the interaction between the -3mm and +3mm parts of each different ore type. Assuming there are n ore types in total, without introducing standard flour, the number of measurement experiments is n×n. When introducing standard flour, the number of measurement experiments is 2n + 1. When the number of ore types exceeds 3, introducing standard flour has an advantage in terms of the number of experiments. In addition, considering that the types of sintering raw materials in some steel mills change frequently, it is very important to measure the sintering bonding performance of newly introduced ores and integrate them into the original system in sintering ore blending. Assuming m newly introduced ores, without introducing standard flour, the number of measurement experiments is 2n×m + m×m. When introducing standard flour, the number of measurement experiments is 2m, and the number of experiments decreases significantly.

[0083] Compared with other similar methods, the present invention first considers that the effects of large particles and fine particles in the iron ore sintering process are different, measures their sintering properties separately and combines the measured results. The sintering bonding index obtained by calculation can be used to evaluate the quality of the ore blending scheme and guide the optimization of the ore blending process. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 Comparison of the number of experiments with and without adhering powder

[0085] Figure 2 Schematic diagram of the test equipment;

[0086] Figure 3 Heating and atmosphere system during the test process;

[0087] Figure 4 Comparison between the sintering bonding index calculated by the present invention and the results of the sintering pot test. DETAILED DESCRIPTION OF THE INVENTION

[0088] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other

[0089] embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0090] See Figure 1, the present invention utilizes a vertical tube furnace and is equipped with a sample injection guide rail, an atmosphere control system, an electronic balance, and a rotary drum screening system to achieve the determination of the liquid-phase bonding effect of iron ore. The vertical tube furnace and the supporting sample injection guide rail and atmosphere control system include a vertical tube furnace, an atmosphere control system, an inlet pipe, a sample injection guide rail, a guide rail motor, a temperature-measuring thermocouple, and a temperature-sample injection control system. The corundum container is filled with corundum balls or +3mm iron ore particles, and the sample to be tested is placed on the flattened corundum balls or +3mm iron ore particles and enters the furnace together with the sample during the test to simulate sintering.

[0091] An evaluation method for the iron ore sintering burdening scheme based on the comprehensive sintering bonding index, and its determination process includes the following steps:

[0092] Single ore screening: Screen out the -3mm particle size ore powder and +3mm particle size ore grains of the i-th single ore, and record the content α of the -3mm part. i ;

[0093] Single ore batching and forming: Mix the -3mm particle size ore powder of the i-th single ore with a flux and water evenly, press it into a shape and dry it for standby; Mix the -0.5mm part of the ore powder with calcium hydroxide flux and water evenly, the addition amount of the flux is 15 to 20 wt.%, and 8 wt.% of water is added. After pressing it into a shape, dry it (pressing conditions: pressure is 10 MPa, pressure holding for 1 min, the size of the agglomerate is Dried in an oven at 120 °C for 2 h); Obtain the ore agglomerate of the i-th single ore.

[0094] Standard powder batching and forming: Use pure reagents to prepare a standard powder with a composition of 77 wt% Fe2O3 - 5 wt% SiO2 - 15 wt% CaO–1 wt% MgO–2 wt% Al2O3 or 72 wt% Fe2O3 - 5 wt% SiO2 - 20 wt% CaO–1 wt% MgO–2 wt% Al2O3, add 8% of the mass of the standard powder of water, mix evenly, press it into a shape and dry it for standby (complete separation of free water);

[0095] Sample weighing: Weigh the dried single ore agglomerate, and record the weight of the i-th single ore agglomerate as m i0 , and record the weight of the standard powder agglomerate as m s0 ; Among them, the ore agglomerate of the i-th single ore is placed on the flat corundum balls, the diameter of the corundum balls is 3mm, and the weight of the corundum balls is 10 times the mass of the ore agglomerate of the i-th single ore used;

[0096] Replace the -3mm particle size sample of the i-th single ore with a standard powder sample, and the remaining steps and the determination of the bonding index BI of the -3mm ore powder of the i-th single ore i The steps and parameters used are exactly the same (including the size and dosage ratio of the corundum balls); that is, spread the corundum balls in the corundum container, and place the standard powder block with a mass of m s0 on the surface of the corundum balls,

[0097] Cover the corundum container with the +3mm ore particles of the i-th single ore, and the mass is m si0 Place the standard powder sample on the surface of the +3mm ore particles of the i-th single ore. The mass of the +3mm ore particles of the i-th single ore used is 10m si0 ;

[0098] Simulation sintering: Use the vertical atmosphere control furnace with a sample injection guide rail to simulate the sintering of the sample according to the sintering heating system and atmosphere control system (as Figure 2 shown: that is, the heating system: heat up to 100°C within 30S, heat up from 100°C to 700°C within 60S, heat up from 700°C to 1000°C within 30s, heat up from 1000°C to 1200°C within 60S, and heat up from 1200°C to 1300°C within 60S. Atmosphere system: below 1000°C, use 10v%O2 - 12v%CO2 - 78v%N2; above 1000°C, use 22v%CO2 - 78v%N2 atmosphere) for the sample;

[0099] Measure the bonding index BI of the -3mm ore powder of the i-th single ore i The method is as follows: Cover the corundum container with corundum balls, and place the green compact of the -3mm particle size ore powder of the i-th single ore with a mass of m i0 on the surface of the corundum balls. Use the set heating system and atmosphere control system to carry out simulated sintering. After sintering, weigh the minerals adhering to the corundum balls together and record it as m i1 ; Calculate the single ore bonding index BI using formula (1) i ;

[0100] BI i =(m i1 - m i0 ) / m i0 (1)

[0101] During the process of measuring the bonding index BI of the -3mm ore powder of the i-th single ore i , there will be some corundum balls that are not adhered to minerals; the mass of these corundum balls is not included in m i1 .

[0102] Measure the bonding index BI of the standard powder s : Replace the -3mm particle size sample of the i-th single ore with the standard powder sample, and the remaining steps and the steps and parameters used for measuring the bonding index BI of the -3mm ore powder of the i-th single ore i are exactly the same (including the size and dosage ratio of the corundum balls); that is, cover the corundum container with corundum balls, and place the standard powder block with a mass of m s0 on the surface of the corundum balls. Use the set heating system and atmosphere control system to carry out simulated sintering. After sintering, weigh the standard substances adhering to the corundum balls together and record it as ms2 ; Calculate the binding index BI of standard flour using formula (2) s ;

[0103] BI s = (m s2 - m s0 ) / m s0 (2)

[0104] The above standard substance is the product obtained after heating and melting the standard flour block

[0105] During the measurement of the binding index BI of standard flour s , there will be some corundum balls that are not contaminated with the standard substance; the mass of this part of the corundum balls is not included in m s2 .

[0106] Measure the binding index CI of the +3mm ore particles in the i-th single ore i ; Spread the +3mm ore particles of the i-th single ore in a corundum container, and place a standard flour sample with a mass of m si0 on the surface of the +3mm ore particles of the i-th single ore. Carry out simulated sintering according to the sintering heating rate system and the atmosphere control system, and weigh the total mass of the standard flour sample used and the +3mm ore particles of the i-th single ore bonded by the standard flour sample used, denoted as m si1 ; Calculate the binding index CI of the +3mm part of the single ore using formula (3) i ;

[0107] CI i = (m si1 - m si0 ) / m si0 (3)

[0108] According to the different -3mm fine particle size content γ and CaO content in different ore blending schemes, the calculation is as follows

[0109] γ = ∑α i β i (4)

[0110] In the formula: γ is the content of -3mm in the mixed material; that is, the mass percentage of -3mm particles in the ore blending scheme

[0111] α i is the mass percentage of the -3mm part in the i-th single ore

[0112] β i is the mass percentage of the i-th single ore in the ore blending scheme

[0113] c(CaO) = R·c(SiO2) / γ (5)

[0114] R is the binary basicity of the ore blending scheme (R = c(CaO) / c(SiO2));

[0115] c(SiO2) is the SiO2 content of the ore blending scheme;

[0116]

[0117]

[0118]

[0119] In the formula: BI i计算 is the calculated value of the -3mm part of the bonding index of the i-th single ore;

[0120] BI s计算 is the calculated value of the bonding index of the standard powder;

[0121] CI i计算 is the calculated value of the +3mm part of the bonding index of the i-th single ore;

[0122] BI ih and BI il are the bonding indices of the -3mm part of the i-th single ore at the flux contents of c(CaO) l and c(CaO) h respectively;

[0123] BI sh and BI sl are the bonding indices of the standard powder at the flux contents of c(CaO) l and c(CaO) h respectively;

[0124] CI ih and CI il are the comprehensive bonding indices of the +3mm part of the i-th single ore at the flux contents of c(CaO) l and c(CaO) h respectively;

[0125]

[0126] In the formula: CSBI is the comprehensive sintering bonding index;

[0127] α i is the mass percentage of the -3mm part in the i-th single ore;

[0128] β i is the mass percentage of the i-th single ore in the ore blending scheme.

[0129] The prerequisite for normal sintering is that the comprehensive sintering bonding index CSBI of the ore blending plan is greater than 1. The larger the CSBI, the better the sintering bonding effect and the better the strength of the sintered product.

[0130] The following is a detailed description of the present invention in conjunction with specific embodiments.

[0131] In this embodiment, standard powders with pure reagent compositions of 77wt% Fe2O3 - 5wt% SiO2 - 15wt% CaO–1wt% MgO–2wt% Al2O3 or 72wt% Fe2O3 - 5wt% SiO2 - 20wt% CaO–1wt% MgO–

[0132] 2wt% Al2O3 are used. 8% of the mass of the standard powder is added with water, and after mixing evenly, it is pressed into shape and dried for standby (free water is completely removed).

[0133] Example 1

[0134] According to the above steps, the bonding index BI and the bonded index CI of 9 iron ores are respectively screened and measured, the sintering bonding indexes of 20 different ore blending plans are calculated, and the optimized ore blending plan is selected. And the calculation results are verified with the results of the sintering pot test of the above ore blending plan.

[0135] Figure 2 The heating system and atmosphere conditions adopted for this experiment are as follows. The particle size composition, bonding index BI and bonded index CI of single ore are shown in Table 1, the ore blending plan is shown in Table 2 in detail, and the calculation results of different ore blending plans are shown in Table 3.

[0136] Table 1 Particle size composition of single ore, bonding index BI of -3mm particle size fraction i , bonding index BI of standard powder s and bonded index CI of +3mm particle size fraction of single ore i

[0137]

[0138] Table 2 Sintering ore blending plan

[0139]

[0140]

[0141] According to formula (4), the content γ of -3mm fine particle size fraction of different ore blending plans can be calculated, and according to formula (5), c(CaO) in different ore blending plans can be calculated; then according to formulas (6 - 8), the bonding indexes of various single ores -3mm, standard and the bonded indexes BI i , BI s and CI of +3mm of each single ore under different ore blending plans can be calculated.i ,; Finally, the comprehensive sintering bonding index CSBI of different ore blending schemes is calculated according to formula (9), as shown in Table 3:

[0142] Table 3 Calculation results of different ore blending schemes

[0143]

[0144] From the above results, it can be seen that the comprehensive sintering bonding indexes CSBI of the ore blending schemes S1, S4, S5, S6, and S15 are relatively high and can be used as preferred ore blending schemes.

[0145] The sintering quality of the above 20 ore blending schemes was verified by the sintering pot test method, and the drum strength results are shown in Table 4:

[0146] Table 4 Sintering pot test results of different ore blending schemes

[0147] Ore blending plan Sinter drum index TI Ore blending plan Sinter drum index TI S1 63.5 S11 58.3 S2 60.9 S12 59.2 S3 63.1 S13 60.0 S4 63.8 S14 60.5 S5 64.7 S15 64.0 S6 65.5 S16 61.4 S7 60.6 S17 59.8 S8 60.1 S18 59.8 S9 61.0 S19 59.9 S10 62.0 S20 59.9

[0148] The relationship between the drum strength index TI of the sintering pot test product and the comprehensive sintering bonding index CSBI was analyzed. As Figure 3 shown, the two show good correlation. And the drum strengths of the above-mentioned preferred ore blending schemes S1, S4, S5, S6, and S15 all reached more than 63.5%.

[0149] Compared with the traditional sintering pot test, this method can calculate the comprehensive sintering bonding index CSBI of different ore blending schemes after measuring the sintering performance of single ores, obtain the preferred ore blending schemes, and the preferred schemes are consistent with the sintering pot test results. However, this method is more convenient and fast compared with the huge-scale sintering pot test. It only takes 2 man-days to measure the sintering properties of the above 9 single ores, while it takes 2 man-days to complete a set of sintering pot tests. In the embodiment, the efficiency difference is 20 times. In addition, this method can also perform ore blending optimization on a larger scale.

[0150] The above embodiments are only examples clearly illustrating the present invention and do not limit the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An evaluation method for the ore blending scheme of iron ore sintering based on the comprehensive sintering binding index, characterized in that, It includes the following steps: Step 1 Obtain the caking index of the -3mm sized ore powder in the i-th single ore 、Obtain the caking index BI of the standard powder s and obtain the caking index CI of the standard powder lumps and the +3mm sized ore particles in the i-th single ore powder i ; Step 1 includes the following steps: Step 1-1 Single ore screening Screen the i-th single ore, screen out the ore powder with a particle size of -3 mm and the ore particles with a particle size of +3 mm, and record the percentage α of the mass of the -3 mm particles in the i-th single ore accounting for the total mass of the i-th single ore i , where i is an integer greater than or equal to 1; Step 1-2 Single ore batching and forming Mix the -3mm sized ore powder of the i-th single ore with fluxes and water evenly, press it into shape after drying to obtain the green compact of the -3mm sized ore powder of the i-th single ore; it is used to measure the caking index of the fine-grained i-th single ore ; Step 1-3 Standard powder batching and forming Prepare standard powder with pure reagents, mix it evenly with water, press it into shape and dry it to obtain a standard powder block; the standard powder block is used to measure the caking index BI of the standard powder s , and is also used to measure the caking index CI of the ore particles with a particle size of +3 mm in the standard powder block and the i-th single ore powder i ; Step 2 Calculate the sintering bonding index based on the sintering ore blending scheme and the properties of the measured single ores; The calculation formula is: ； In the formula: CSBI is the comprehensive sintering bonding index; α i is the content of the -3mm part of the i-th single mineral; β i is the mass percentage ratio of the i-th single ore in the mixed ore, that is, the mass percentage of the dried i-th single ore in the dried mixed ore in the sintering ore blending plan; The ore blending scheme includes selecting n single ores for mutual blending; n is a positive integer greater than or equal to 1; Step 3 Selection of optimized ore blending scheme Select the corresponding optimized ore blending scheme according to the principle that the CSBI value is greater than 1 and the larger the better.

2. The evaluation method of iron ore sintering burden distribution plan based on comprehensive sintering binding index according to claim 1, wherein: Method for measuring the bonding index BI of -3mm ore powder in the i-th single ore i is as follows: Spread corundum balls in a corundum container, and place the green compact of the -3mm sized ore powder of the i-th single ore with a mass of m i0 on the surface of the corundum balls. Carry out simulated sintering using the set heating system and atmosphere control system. After sintering, weigh the minerals adhering to the corundum balls together and record it as m i1 ; Calculate the bonding index BI of the single ore using formula (1) i ; （1） Define the mass of the -3mm sized powder compact of the i-th single ore to be placed on the surface of the corundum balls as A; then the mass of the corundum balls placed in the corundum container is greater than or equal to 10A; Measuring the binding index BI of standard flour s When, spread corundum balls in a corundum container, and place a standard flour block with a mass of m s0 on the surface of the corundum balls, and perform simulated sintering using the set heating system and atmosphere control system. After sintering, weigh the standard object with corundum balls adhered to it, and record it as m s2 ; Calculate the binding index BI of the standard flour using formula (2) s ; （2） The above standard substance is the product obtained after heating and melting the standard powder block; The mass of the corundum balls used is greater than or equal to 10m s0 ; the diameter of the corundum balls is 3 - 5mm; Measure the adhesion index CI of +3mm ore particles in the i-th single ore i ; Spread the +3mm ore particles of the i-th single ore in a corundum container, and place a standard powder sample with a mass of m si0 on the surface of the +3mm ore particles of the i-th single ore. Conduct simulated sintering according to the sintering heating rate system and the atmosphere control system, and weigh the total mass of the used standard powder sample and the +3mm ore particles of the i-th single ore adhered by the used standard powder sample, denoted as m si1 ; Calculate the adhesion index CI of the +3mm ore particles of the single ore using formula (3) i ; Measure the adhesion index CI of the +3mm ore particles in the i-th single ore i When measuring, the mass of the +3mm ore particles of the i-th single ore used is greater than or equal to 5m si0 ; （3）。 3. The evaluation method of the iron ore sintering burdening scheme based on the comprehensive sintering binding index according to claim 1, wherein: The flux is selected from at least one of calcium oxide, calcium hydroxide, calcium carbonate, magnesium carbonate reagents or slaked lime, limestone, dolomite, serpentine, magnesite used in industrial production; its dosage is: calculated as calcium oxide, adding 10-30% of the flux based on the mass of the -3mm sized powder of the i-th single ore; Add water according to the ratio of 0.8-1.2 mL of water per 10 g of ore powder; that is, mix the -3mm sized powder of the i-th single ore with the flux and water evenly, press into shape and dry to obtain the -3mm sized powder compact of the i-th single ore; 0.8-1.2 mL of water is used for 10 g of the -3mm sized powder of the i-th single ore; similarly, prepare the standard powder with pure reagents, mix it evenly with water, press into shape and dry to obtain the standard powder block; that is, 0.8-1.2 mL of water is used for 10 g of the standard powder.

4. The evaluation method of iron ore sintering burden distribution plan based on comprehensive sintering binding index according to claim 1, characterized in that: The forming pressure is 2-20 MPa, and the sample size is a φ10×5 mm cylinder.

5. The evaluation method of iron ore sintering burden distribution plan based on comprehensive sintering binding index according to claim 1, wherein: The composition range of the standard powder is between 60~85 wt% Fe2O3 - 4~6 wt% SiO2 - 10~20 wt% CaO - 0~5 wt% MgO - 0~7 wt% Al2O3.

6. The evaluation method for the iron ore sintering burden distribution plan based on the comprehensive sintering binding index according to claim 5, wherein: Set the standard powder compositions to 72 wt% Fe2O3 - 5 wt% SiO2 - 20 wt% CaO - 1 wt% MgO - 2 wt% Al2O3 and 77 wt% Fe2O3 - 5 wt% SiO2 - 15 wt% CaO - 1 wt% MgO - 2 wt% Al2O3 respectively.

7. A method for evaluating the ore blending scheme for iron ore sintering based on the comprehensive sintering bonding index according to claim 5, characterized in that: Determine the bonding index BI of the i-th single ore - 3mm ore powder under different flux contents i , the bonding index BI of the standard powder s and the bonding index CI of the +3mm ore particles i . The flux content range is set according to the fine particle size ratio and sintering basicity requirements under different ore blending schemes. The lower and upper limits of the flux content c(CaO) within the measurement range l , c(CaO) h of the bonding index BI i and the bonding index CI i are BI il , BI ih , CI il and CI ih respectively. The above measurement results can be used to calculate the bonding index BI at the actual flux content c(CaO) in the -3mm particle size under different ore blending schemes i and the bonding index CI of the +3mm ore particles when the standard powder and the +3mm ore particles act under the corresponding flux content i . The calculation of the -3mm fine particle size content γ and the flux content c(CaO) of the ore blending scheme to be measured is shown in the following formula (4): （4） In the formula: γ is the content of -3mm in the blended material obtained from the ore blending scheme; α i is the mass percentage of the -3mm ore particles in the i-th single ore; β in the ore blending plan i is the mass percentage of the i-th single ore in the ore blending plan; （5） Where: c(CaO) is the CaO content used when calculating the single ore BI i , BI s , CI i for different ore blending schemes; R is the binary basicity in the ore blending scheme; c(SiO2) is the SiO2 content in the ore blending scheme.

8. The evaluation method of the iron ore sintering burden distribution plan based on the comprehensive sintering binding index according to claim 5, wherein: Set the lower limit and upper limit of the flux content to c(CaO) l = 15 wt%, c(CaO) h = 20 wt%.

9. The evaluation method of iron ore sintering burden distribution plan based on comprehensive sintering binding index according to claim 8, characterized in that: Obtain the corresponding parameters equivalent to the amount of flux added in the ore blending scheme by interpolation calculation, calculated as calcium oxide, It is necessary to obtain the caking index BI of the i-th single ore -3mm ore powder under different flux contents in the ore blending scheme i计算 When; select the lower limit and upper limit c(CaO) of the flux content in the ore blending scheme l , c(CaO) h , through formula (1) and the corresponding test method, obtain BI ih , BI il ; where BI ih , BI il are respectively the caking indexes of the i-th single ore in the -3mm part under the flux contents of c (CaO) l , c (CaO) h ; then calculate according to formula (6): （6） c (CaO) in formula 6 is calculated according to formula 5; It is necessary to obtain the caking index BI of the standard powder under different flux contents in the ore blending plan s计算 When; select the lower limit and upper limit c(CaO) of the flux content l 、c(CaO) h 、Through formula (2) and the corresponding test method, obtain BI sh 、BI sl ; BI sh 、BI sl are the caking indexes of the standard powder when the flux content is c(CaO) l 、c(CaO) h respectively; then calculate BI s计算 according to formula (7); （7） c (CaO) in formula 7 is calculated according to formula 5; Two kinds of standard flour are selected. One is 72wt% Fe2O3 - 5wt% SiO2 - 20wt% CaO - 1wt% MgO - 2wt% Al2O3, and the other is 77wt% Fe2O3 - 5wt% SiO2 - 15wt% CaO - 1wt% MgO - 2wt% Al2O3; It is necessary to obtain the caking index CI of the +3mm ore powder of the i-th single ore under different flux contents in the ore blending plan i计算 When; select the lower limit and upper limit of the flux content c(CaO) l , c(CaO) h , and obtain CI through formula (3) and the corresponding test method ih , CI il ; where BI ih , BI il are respectively the comprehensive caking indexes of the +3mm part of the i-th single ore under the flux contents of c(CaO) l , c(CaO) h ; then calculate CI according to formula (8) i计算 : （8） In Formulas 6, 7, and 8: BI i计算 is the calculated value of the -3mm partial caking index of the i-th single mineral; BI s计算 is the calculated value of the caking index of standard flour; CI i计算 is the calculated value of the caking index for the +3 mm fraction of the i-th single mineral; BI ih and BI il are the caking indices of the i-th single ore for ore particles smaller than -3 mm at fluxes of c (CaO) l and c (CaO) h respectively. BI sh and BI sl are the caking indices of standard flour at flux contents of c (CaO) l and c (CaO) h respectively; CI ih 、CI il are the comprehensive bonding indices of the +3mm ore particles of the i-th single ore at the flux contents of c(CaO) l and c(CaO) h respectively. （9） In the formula: CSBI is the comprehensive sintering bonding index; α i is the mass percentage of the -3mm ore particles in the i-th single ore; β i is the mass percentage of the i-th single ore in the ore blending scheme; BI in Formula 9 i is the measured value or BI i计算 value, and BI s is the measured value or BI s计算 value; CI i is the measured value or CI i计算 value.

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