Method for predicting yield of sintered ore of iron ore powder

Abstract

The invention discloses a method for predicting the yield of sintered ore of iron ore powder. The method comprises the following steps: (1) carrying out component analysis on the iron ore powder used for sintering and blending ore in an iron and steel plant; (2) uniformly mixing the iron ore powder and a calcium-containing flux, briquetting, carrying out gradient roasting treatment on the obtained block mass within a set temperature range, and cooling the block mass roasted at different temperatures to obtain the roasted block mass; (3) respectively carrying out drum treatment on the roasted block masses, and then screening to obtain the drum strength of the roasted block masses at different temperatures; (4) solving an average value of the drum strength of the roasted agglomerates at different temperatures, and defining the average value as the drum strength of the iron ore powder agglomerates; and (5) carrying out granulation, material distribution and ignition sintering on the iron ore powder to obtain the sintered ore yield, and carrying out fitting analysis on the drum strength of the iron ore powder block mass and the sintered ore yield to obtain the function relationship between the drum strength of the iron ore powder block mass and the sintered ore yield. According to the method, the sintered ore yield can be predicted through the drum strength of the micro sintering experiment, guidance is provided for sintering production, and efficiency improvement, energy conservation and consumption reduction in the sintering production process are facilitated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sintering, and particularly relates to a method for predicting finished product rate of iron ore powder sinter. BACKGROUND

[0002] At present, there are various iron ore sintering ore matching methods aiming to improve the quality and yield of sinter. However, in actual operation, due to the large fluctuation of iron ore resource quality, the stability of ore matching is challenged. At the same time, the traditional ore matching method mainly depends on experience and lacks precise data support, resulting in unstable sinter quality and affecting subsequent steel production. These problems highlight the urgency of improving the ore matching method, and more scientific and accurate technical means need to be introduced to meet the needs of industry development.

[0003] With the increasing variety of sinter raw materials, the chemical composition and physicochemical properties of the raw materials become extremely complex, resulting in increased difficulty in ore matching. The mainstream ore matching methods mainly include traditional sintering experiment ore matching, normal temperature property guided ore matching and high temperature property guided ore matching. Although the traditional sintering experiment is close to the actual situation and has good effect, it has large workload and high cost; the normal temperature property guided ore matching is based on the normal temperature physicochemical performance of the ore powder, but it cannot directly reflect the high temperature sintering behavior, and the accuracy of ore matching is insufficient; the high temperature property guided ore matching is based on the behavior law of the ore in high temperature sintering to refine indexes for guiding ore matching, but it has problems such as deviation of pretreatment from the actual situation and repeated and complex evaluation, and its promotion is limited.

[0004] In summary, the existing ore matching methods have many problems, and it is imperative to develop a new sinter ore matching method. Therefore, developing a method for predicting the finished product rate of iron ore powder sinter is beneficial to improving the accuracy and practicality of ore matching. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a simple, low-cost and accurate method for predicting the finished product rate of iron ore powder sinter, which gives the preferred iron ore powder or ore matching scheme when matching complex ore, and is beneficial to the stable and smooth operation of blast furnace smelting.

[0006] To solve the above technical problems, the present application adopts the following technical scheme:

[0007] The present application provides a method for predicting the finished product rate of iron ore powder sinter, comprising the following steps:

[0008] (1) analyzing the composition of the iron ore powder used for sinter ore matching in a steel plant to determine the content of total iron (TFe), CaO and SiO2 in the iron ore powder;

[0009] (2) mixing the iron ore powder in step (1) with calcium-containing flux and then briquetting, gradient roasting the obtained briquettes in a set temperature range, cooling the briquettes roasted at different temperatures, and obtaining the roasted briquettes;

[0010] (3) The drum strength of the iron ore powder briquettes is obtained by respectively performing a drum treatment on the calcined briquettes obtained in step (2) and then performing a screening, so as to obtain the drum strength of the briquettes calcined at different temperatures;

[0011] (4) The average value of the drum strength of the briquettes calcined at different temperatures obtained in step (3) is calculated, which is defined as the drum strength of the iron ore powder briquettes;

[0012] (5) The sintered ore yield is obtained by performing a granulation, a material distribution and an ignition sintering on the iron ore powder in step (1), and the function relationship between the drum strength of the iron ore powder briquettes and the sintered ore yield is obtained by performing a fitting analysis on the drum strength of the iron ore powder briquettes and the sintered ore yield.

[0013] Preferably, in step (1), the iron ore powder is a sintering raw material containing iron, and the raw material of the iron ore powder includes one or more of hematite, magnetite, siderite, sintered return fines and iron-containing scrap of a steel plant.

[0014] Further preferably, the hematite includes limonite and / or specularite.

[0015] Preferably, in step (1), the iron ore powder is a full-size grade iron ore powder.

[0016] Preferably, in step (2), the calcium-containing flux includes one or more of limestone, quicklime and slaked lime, and the particle size of the calcium-containing flux is greater than or equal to 90% of -200 mesh.

[0017] Further preferably, the addition amount of the calcium-containing flux is constrained according to the alkalinity (mass ratio of CaO to SiO2) of the sintered ore on site, or the alkalinity of the mixture is 1.5-2.5.

[0018] Preferably, in step (2), the gradient calcination of the briquettes is performed every 25℃ in the range of 1250-1350℃, and the calcination time is 5-30 min, so as to obtain the briquettes calcined at different temperatures.

[0019] Preferably, in step (2), the diameter of the briquettes is 20-30 mm, and the height is 20-30 mm.

[0020] Preferably, in step (3), the AC drum is used for the treatment, and then the screening is performed, and the proportion of +0.5 mm is defined as the drum strength of the calcined briquettes.

[0021] Further preferably, the number of the briquettes used for measuring the AC drum index is 10-20.

[0022] Further preferably, the rotation speed of the AC drum used for the measurement is 40-60 r / min, and the total number of rotations is 200.

[0023] Preferably, in step (5), based on the function relationship between the drum strength of the iron ore powder briquette and the sintered ore yield, the greater the drum strength of the iron ore powder briquette, the higher the corresponding sintered ore yield of the iron ore powder.

[0024] Compared with the prior art, the present application has the advantages of:

[0025] The present application can provide guidance for sintering production by predicting the sintered ore yield through drum experiments and forming a guiding relationship between the performance of iron ore powder and sintered ore, saving manpower, material resources and time required for conventional sintering cup experiments to determine the sintering performance of iron ore powder, and can optimize high-quality sintered ore, which is helpful for energy saving and consumption reduction in the sintering production process. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The figure is a direct relationship between the drum strength of the iron ore powder of embodiment 1 of the present application and the sintered ore yield.

[0027] Figure 2 The figure is a process flow diagram of the present application. DETAILED DESCRIPTION

[0028] The present application will be further described below in combination with the drawings and specific preferred embodiments, but the protection scope of the present application is not limited thereby. The materials and instruments used in the following embodiments are all commercially available.

[0029] The main chemical components of seven commercial iron ore powders were analyzed to determine the content of total iron (TFe), CaO and SiO2, and the results are shown in Table 1.

[0030] Table 1 Analysis table of main chemical components of seven iron ore powders (unit: wt%)

[0031] Iron ore TFe CaO SiO2 Class A (TFe-Mg concentrate) 53.15 0.26 4.39 Magnetite B (Brazilian concentrate) 63.32 0.032 6.24 Limonite C (Silk Road) 58.56 0.072 7.61 Limonite D (PB powder) 61.23 0.092 3.41 Limonite E (South African concentrate) 64.26 0.045 4.21 Specularite F (Brazilian coarse powder) 64.45 0.064 2.66 Limonite G (Mack powder) 60.52 0.06 4.50 Limonite

[0032] The present application will be further described below in combination with the drawings and specific preferred embodiments, but the protection scope of the present application is not limited thereby. The materials and instruments used in the following embodiments are all commercially available.

[0033] Embodiment 1

[0034] A method for predicting the sintered ore yield of iron ore powder, as shown in Figure 2 , comprises the following steps:

[0035] I. Briquetting and roasting experiment:

[0036] (1) Sintering ore blending adopts 7 kinds of iron ore A to G, all of which are full particle size iron ore powder, and the flux used is calcium carbonate reagent (the particle size of calcium-containing flux is-200 mesh≥90%), the iron ore powder and calcium carbonate reagent are mixed according to the basicity adjustment of 2.0, 5% moisture is added to the mixed material, and then pressed into 50 briquettes with a diameter of 30 mm and a height of 30 mm, every 10 briquettes are put into a muffle furnace at 1250℃, 1275℃, 1300℃, 13625℃ and 1350℃ for roasting for 10 min, after roasting, the briquettes are naturally cooled to room temperature, and the AC drum strength is determined (+0.5mm ratio), the rotation speed of the AC drum is 50r / min, a total of 200 rotations, and the drum strength of the briquettes after roasting under different temperature conditions is shown in Table 2.

[0037] Table 2 Drum strength of seven kinds of iron ore powder (unit: %)

[0038] Iron ore 1250℃ 1275℃ 1300℃ 1325℃ 1350℃ Average A (TFe-Mg concentrate) 60.2 65.2 72.6 80.6 88.5 73.42 B (Brazilian concentrate) 55.6 60.4 70.2 84.5 91.5 72.44 C (Silk Road) 44.8 70.5 82.6 88.6 96.2 76.54 D (PB powder) 38.4 52.9 68.6 78.6 86.2 64.94 E (South African concentrate) 65.2 70.9 78.2 90.5 97.6 80.48 F (Brazilian coarse powder) 40.6 50.3 65.4 75.9 85.7 63.58 G (Mack powder) 62.3 68.9 85.6 95.6 98.1 82.1

[0039] II. Sintering cup experiment verification

[0040] (1) Sintering experiments of the preset 7 kinds of iron ore powder under different water and carbon are carried out, the specific steps are as follows: weigh the iron-containing raw materials, fuel, flux and returned ore, and add them to the φ1500mm×500mm scale automatic mixer for mixing, then add 7% of additional water and mix. The mixed raw material is sent to the φ600mm×2000mm spiral cylinder granulator for granulation, the rotation speed is set to 30r / min, and the granulation time is 5min. After granulation, the material is laid and sintered;

[0041] (2) Before laying, 3kg of bedding material (16-25mm) is added to the φ300mm×1000mm sintering cup, the mixed material after granulation is evenly laid in the sintering cup, after laying, the material column is shortened by 20mm by light pressing with the material press, then the sintering cup is fully laid, and the material layer thickness is about 880mm;

[0042] (3) Natural gas is used for sintering ignition, the ignition temperature is 1150±20℃, the ignition time is 1.5min, and the ignition negative pressure is 6kPa. From the start of ignition to the time when the sintering waste gas temperature reaches the highest and then starts to drop is the sintering time. After reaching the sintering endpoint, the sintering machine is turned off when the waste gas temperature is lower than 200℃, the sinter is unloaded and naturally cooled in the air, and finally the sinter is dropped, screened and the yield is calculated. The yield is the weight of the qualified sinter with the required particle size (usually 5mm and above) accounted for the total weight of the mixed material put into the sintering machine (including iron-containing raw materials, fuel, flux, returned ore, etc.).

[0043] The drum strength of the iron ore powder briquettes and the sinter yield data are fitted and analyzed as follows Figure 1As shown in the figure, the drum strength obtained by the method proposed in this invention has a good correlation with the sinter yield (Y=0.313X+57.314, R). 2 = 0.9466), indicating that this method can predict the yield of the corresponding sintered ore, avoiding the need to conduct a large number of sintering cup experiments and saving manpower and resources.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method of predicting the yield of iron ore fines sinter product, characterised by, The method comprises the following steps: (1) performing component analysis on iron ore powder used for sintering ore blending in a steel plant; (2) mixing the iron ore powder in step (1) with calcium-containing flux, then briquetting, gradient roasting the obtained briquettes in a set temperature range, cooling the briquettes roasted at different temperatures, and obtaining the roasted briquettes; (3) performing drum treatment on the roasted briquettes obtained in step (2) respectively, then performing screening, and obtaining the drum strength of the briquettes roasted at different temperatures; (4) calculating the average value of the drum strength of the briquettes roasted at different temperatures obtained in step (3), and defining the average value as the drum strength of the iron ore powder briquettes; (5) performing granulation, distribution and ignition sintering on the iron ore powder in step (1), obtaining the sintered ore yield, fitting and analyzing the drum strength of the iron ore powder briquettes and the sintered ore yield, and obtaining the functional relationship between the drum strength of the iron ore powder briquettes and the sintered ore yield.

2. A method of predicting the yield of sintered iron ore fines as claimed in claim 1 wherein, In step (1), the iron ore powder is an iron-containing raw material for sintering, and the raw material of the iron ore powder includes one or more of hematite, magnetite, siderite, sintered return fines and iron-containing scrap of a steel plant.

3. A method of predicting the yield of sintered iron ore fines as claimed in claim 2, wherein, The hematite includes limonite and / or specularite.

4. The method of predicting the yield of sintered iron ore fines as claimed in claim 1 wherein, In step (1), the iron ore powder is a full-size iron ore powder.

5. The method of predicting the yield of sintered iron ore fines as claimed in claim 1 wherein, In step (2), the calcium-containing flux includes one or more of limestone, quicklime and slaked lime, and the particle size of the calcium-containing flux is greater than or equal to 90% of -200 mesh.

6. A method of predicting the yield of sintered iron ore fines as claimed in claim 5 wherein, In step (2), the addition amount of the calcium-containing flux is constrained according to the alkalinity (mass ratio of CaO to SiO2) of the sintered ore on site, or the addition amount is set according to the alkalinity of the mixture being 1.5-2.

5.

7. The method of predicting the yield of sintered iron ore fines as claimed in claim 1 wherein, In step (2), the briquettes are gradient roasted at every 25℃ in the range of 1250-1350℃, and the roasting time is 5-30 min, to obtain the briquettes roasted at different temperatures.

8. The method of predicting the yield of sintered iron ore fines as claimed in claim 1 wherein, In step (2), the diameter of the briquettes is 20-30 mm, and the height is 20-30 mm.

9. The method of predicting the yield of sintered iron ore fines as claimed in claim 1 wherein, In step (3), the AC drum is used for treatment, and then screening is performed, and the proportion of +0.5 mm is defined as the drum strength of the roasted briquettes; The number of briquettes used for determining the AC drum index is 10-20; The rotation speed of the AC drum used for determination is 40-60 r / min, and a total of 200 rotations are performed.

10. The method of predicting the yield of sintered iron ore fines as claimed in claim 1 wherein, In step (5), based on the functional relationship between the drum strength of the iron ore powder briquettes and the sintered ore yield, the greater the drum strength of the iron ore powder briquettes, the higher the sintered ore yield corresponding to the iron ore powder.

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