CN113051847A - Blast furnace slag thermal stability evaluation method and optimization method - Google Patents
Blast furnace slag thermal stability evaluation method and optimization method Download PDFInfo
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Abstract
A blast furnace slag thermal stability evaluation method and an optimization method relate to the technical field of iron making and comprise the following steps: s1: obtaining the quality and production temperature of each component in the slag; calculating a first enthalpy change value of the slag heating stage based on thermodynamic software; calculating a second enthalpy change value of the slag heating stage based on a thermodynamic reaction formula; s2: taking the average value of the first enthalpy variable value and the second enthalpy variable value as an actual enthalpy variable value; s3: adjusting the alkalinity of the slag, and repeatedly executing the steps S1-S2 to obtain actual enthalpy change values of a plurality of groups of slag with different alkalinity; s4: based on a second law of thermodynamics, taking the average value of actual enthalpy change values of a plurality of groups of slag with different alkalinity as the total heat required by the slag temperature rise stage; s5: and inputting the total heat into the furnace slag, and calculating the change rate of the furnace slag viscosity after the total heat is input along with the alkalinity of the furnace slag. The method provided by the invention can realize quantitative research on the thermal stability of the blast furnace slag, and avoid the problems of overheating or insufficient furnace temperature of the blast furnace slag and the like.
Description
Technical Field
The invention relates to the technical field of iron making, in particular to an evaluation method and an optimization method for thermal stability of blast furnace slag.
Background
The reasonable utilization of energy is the direction of exploration and development of various industries, and along with the continuous development of economy and society, the demand on energy is increasing day by day. The ferrous metallurgy industry, as the backbone industry, has a particularly great demand for energy, with blast furnace iron making being one of the most energy consuming parts of the entire industry. In the blast furnace iron-making process, a part of heat is not reasonably utilized, and in order to ensure the physicochemical reaction temperature required by smelting, slag is always overheated, which has adverse effect on the service life of blast furnace equipment. Therefore, the control of reasonable heat in the slag is of great importance to energy conservation and emission reduction of the steel industry and the improvement of energy utilization efficiency. In order to realize reasonable control of heat in the slag, the premise is to determine the thermal stability of the slag.
The thermal stability of the slag is the ability of the slag to resist thermal fluctuation, and when the input heat in the smelting equipment is changed, the slag with stronger thermal stability can only produce smaller temperature change under the condition that the input heat fluctuates, thereby avoiding the adverse effect on the melt fluidity and slag-metal reaction in the smelting process.
In recent years, with the continuous large-scale blast furnace and the change of the components of the charging materials, the requirement on the thermal stability of the slag is higher and higher. However, due to the reduction of the amount of high-grade and high-quality ores and the increase of price and cost, imported ores and low-grade ores become the choice of large enterprises. But with too much Al in the furnace2O3The thermal stability of the slag is deteriorated by the components such as MgO, and the slag contains excessive Al2O3In the process, a high-melting-point compound with strong crystallization capacity is generated, so that the enthalpy change of slag is increased, the fluidity is poor, and the metallurgical performance is deteriorated;when the content of MgO is too high, high-melting-point substances are formed, so that the viscosity of slag is increased, the fluidity is poor, the sintering melt amount is increased, the coke ratio is increased, and the economic iron-making principle is not met; furthermore, the method is simple. The heat fluctuation is obvious when the blast furnace is stopped and rebleed, and the heat stability of the slag can also obviously influence the smelting. The slag is used as one of main byproducts of the blast furnace, the related high-temperature physical and chemical processes of the slag in the smelting process have been researched more, but the thermal stability of the slag is more closely related to energy conservation, emission reduction and high-efficiency production, and a system evaluation method for the thermal stability is not formed at present.
In practical production, the addition of the blast furnace fuel is a link which is easy to control. When the fluctuation of the ore components of the furnace burden leads to the change of the slag components, if the thermal stability of the slag can be determined, the heat entering the furnace can be adjusted in time, so that the slag starts from the thermal stability of the slag, a reasonable theoretical heat value is obtained by matching, the energy utilization rate is improved, and the fluctuation of the furnace temperature of the blast furnace is slowed down. The blind guess of the amount of the fuel entering the furnace can cause the increase of the consumption of coke and coal powder, thereby causing the resource waste and the increase of the economic cost, and being not beneficial to the flow adjustment of the slag in the blast furnace and influencing the metallurgical performance. Therefore, the method for evaluating the thermal stability of the slag has important significance, can improve the buffer capacity of the slag and the heat utilization efficiency of the slag when the condition of the blast furnace fluctuates, and can also adjust the components of the slag in a targeted manner according to the evaluation result to enable the slag in the furnace to tend to be in a better thermal stability state, thereby having significance for efficient, stable and smooth blast furnace smelting in China.
The method is used for the related calculation of the thermal stability of the blast furnace slag through a reaction balance calculation module in thermodynamic software. And then reducing software errors through mathematical integral calculation, obtaining a thermal stability evaluation image which is very close to an actual result, and guiding actual production.
Compared with the traditional blast furnace thermal fluctuation empirical estimation method, the method can realize accurate measurement of overheating or insufficient heat in the furnace through the evaluation of the thermal stability of the furnace slag, can be timely and quickly applied to large-scale production, is more important, combines the software calculation result with the thermodynamic equation result to greatly offset the system error, has wide industrial application prospect, and has important social benefits for finally solving the problem of the irregularity of the thermal fluctuation of the blast furnace slag.
Disclosure of Invention
The invention provides a method for evaluating thermal stability of blast furnace slag. The method fully utilizes a reaction balance calculation module of metallurgical thermodynamic software and mathematical integral calculation to obtain a thermal stability numerical image which is very close to an actual result, realizes quantitative research on the thermal stability of the blast furnace slag, further performs accurate and reliable production guidance, and effectively avoids the problems of overheating or insufficient furnace temperature of the blast furnace slag and the like.
According to a first aspect of the present invention, there is provided a method for evaluating thermal stability of blast furnace slag, the method comprising the steps of:
s1: obtaining the quality and production temperature of each component in the slag;
s2: calculating a first enthalpy change value of the slag heating stage based on thermodynamic software;
calculating a second enthalpy change value of the slag heating stage based on a thermodynamic reaction formula;
s3: taking the average value of the first enthalpy variable value and the second enthalpy variable value as an actual enthalpy variable value;
s4: adjusting the alkalinity of the slag to obtain a plurality of groups of slag with different alkalinity, and repeatedly executing the steps S1-S3 to obtain actual enthalpy change values of the plurality of groups of slag with different alkalinity;
s5: based on a second law of thermodynamics, taking the average value of actual enthalpy change values of a plurality of groups of slag with different alkalinity as the total heat required by the slag temperature rise stage;
s6: inputting total heat to the furnace slag, and calculating the change rate of the furnace slag viscosity after the total heat is input along with the change of the furnace slag alkalinity;
among them, the larger the absolute value of the change rate of slag viscosity, the worse the thermal stability of the slag.
Further, the viscosity change rate is calculated as follows:
wherein VCR is the slag viscosity change rate etajIs the slag viscosity, and j is a positive integer.
Further, the production temperature is in the range of 1200-1600 ℃.
Further, the first enthalpy change value is calculated as follows:
inputting the mass of each component in the slag into thermodynamic calculation software, and respectively calculating the enthalpy value H of the slag at the temperature of 298K298And the enthalpy value H of the slag at the production temperature TtSaid first enthalpy change value Δ HA＝Ht-H298。
Further, the second enthalpy change value is calculated in the following manner:
and inquiring an inorganic crystal structure database according to the mass of each component in the slag and the production temperature to obtain the specific heat capacity of the slag, and calculating a second enthalpy change value by using the specific heat capacity of the slag.
Further, the specific heat capacity of the slag is calculated as follows:
CpCaO＝1.048-2.046×104T-2-2.388T-1/2+1.836×106T-3(T＝298～2845K)
CpMgO＝1.516-1.541×104T-2-7.349T-1/2+1.45×104T-3(T＝298～3098K)
in the formula, CpiIs the specific heat capacity value of a substance i in the slag, the substance i comprises CaO、SiO2、MgO、Al2O3Any one of the above; m isiIs the mass of substance i; t is the actual calculated temperature;
further, the second enthalpy change value is calculated as follows:
ΔHB＝∑miΔHi
ΔHiis the enthalpy change value of substance i in the slag; deltatrHiIs the enthalpy of crystallization transition of substance i in the slag; deltal sHiIs the enthalpy of solid-liquid transition of substance i; t istrIs the transition temperature; t isMIs the slag melting temperature; t is the actual calculated temperature; Δ HBIs a second enthalpy change value; m isiIs the mass of substance i; s is solid phase crystallization; l is liquid phase crystallization.
Further, the evaluation method further comprises the steps of inputting the total heat quantity to the slag linearly, and calculating the slag temperature change rate in the total heat quantity input process, wherein the larger the absolute value of the slag temperature change rate is, the poorer the thermal stability of the slag is.
According to a second aspect of the present invention, there is provided a blast furnace slag optimization method, the method comprising:
and (4) finely adjusting the slag components for multiple times, repeating the thermal stability evaluation method, and selecting the slag component with the smallest absolute value of the slag viscosity change rate as the optimal slag.
Further, the fine adjustment of the slag components comprises one or more of fine adjustment of components, fine adjustment of alkalinity and fine adjustment of magnesium-aluminum ratio;
wherein the component fine tuning comprises adjusting a component of the slag;
the fine adjustment range of the alkalinity fine adjustment is 0.7-1.4;
the fine adjustment range of the fine adjustment of the magnesium-aluminum ratio is 0.3-1.0.
Compared with the prior art, the blast furnace slag thermal stability evaluation method has the following advantages:
the prediction of a plurality of domestic blast furnaces on the furnace temperature has hysteresis, the charging amount of fuel is not matched with the component change of furnace charge in time, so that the problem of insufficient slag-metal reaction caused by overheating slag or insufficient temperature easily occurs in the production, and how to reasonably distribute smelting energy has attracted the great attention of ironmaking workers. The thermal stability of the slag is judged by experience, so that a uniform measurement standard is difficult to form, and the slag is difficult to popularize in a large range. The evaluation method is based on the heat absorption and release behaviors of melts in metallurgy, the quenching slag taken out of a furnace is firstly made into powder, then the sample components are determined, the enthalpy data and the viscosity data of the component slag under a certain temperature step length are calculated by utilizing metallurgy thermodynamic software, and finally the thermal stability parameters of the slag are obtained through integral calculation and mapping.
On the basis of mastering the components of the slag, the temperature and the viscosity of the slag under the condition of fixed heat are solved, and the obtained viscosity data is analyzed and plotted to obtain the parameters of the thermal stability performance of the slag. The method has the advantages of simple and convenient operation, easy mastering and wide application range, and can quickly evaluate the thermal stability of different slags. The method not only can realize reasonable energy distribution to the blast furnace slag, but also can give optimization suggestions from the aspects of temperature and components, solves the problem that the heat fluctuation of the slag in the blast furnace is difficult to predict in the blast furnace ironmaking process, and has wide industrial application prospect.
Drawings
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.
In the drawings:
FIG. 1 is a schematic flow chart of a blast furnace slag thermal stability evaluation method according to the present invention;
FIG. 2 is a graphical illustration of the temperature quantification with heat fluctuation according to an embodiment of the present invention;
FIG. 3 is a graphical illustration of the thermal stability quantification according to an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.
The terms first, second and the like in the description and in the claims of the present invention are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
A plurality, including two or more.
And/or, it should be understood that, as used herein, the term "and/or" is merely one type of association that describes an associated object, meaning that three types of relationships may exist. For example, a and/or B, may represent: a exists alone, A and B exist simultaneously, and B exists alone.
As shown in figure 1, the method for evaluating the thermal stability of the blast furnace slag is based on the second law of thermodynamics, provides a concept of digitizing the thermal stability of the specific blast furnace slag, fully utilizes a metallurgical thermodynamics database and thermodynamics calculation, deduces a numerical image capable of representing the thermal stability of the slag by taking chemical components and actual temperature of the blast furnace slag as parameters, obtains an optimized strategy aiming at the specific slag through a calculation result, and further improves the thermal stability of the slag by finely adjusting the components of the specific slag, so that the smelting production process is more stable. The evaluation method specifically comprises the following steps:
firstly, drying the slag taken out of the blast furnace, removing water in the slag, grinding the slag into micro powder, carrying out laboratory analysis, and determining main chemical components (CaO and SiO) of the slag2、MgO、Al2O3Etc.). The actual temperature of the slag in the blast furnace is measured on site by a thermometric instrument, denoted by T, in units: K.
wherein the numerical range of the on-site actual measurement temperature T of the blast furnace slag is 1200-1600 ℃;
the main chemical composition range of the slag is that the mass percent CaO is 25-49%; mass% SiO2＝25～49％；mass％MgO＝4～12％；mass％Al2O3＝10～25％。
Secondly, assuming that the melt conforms to the second law of thermodynamics under high temperature conditions, it can be known that the enthalpy change value of the slag at a fixed temperature section is equal to the heat input during the temperature rise of the slag under constant pressure conditions, namely:
ΔQ＝ΔU+PΔV＝ΔH
in the formula, delta Q is the total energy change of the slag in the temperature rise process, J; delta U is the internal energy variation value J of the slag; p is air pressure Pa; Δ V is the value of the change in slag volume, m3(ii) a And deltaH is the enthalpy change value J of the slag in the temperature rising process.
Thirdly, the main components (CaO, SiO) of the slag2、MgO、Al2O3) Inputting into metallurgical thermodynamic calculation software such as Thermo-calc or FactSage according to its mass (or mass percentage) to obtain enthalpy value H of slag at 298K298。
Fourthly, calculating the heat capacity value C of the slag at the actual production temperature TptEnthalpy value HtThe enthalpy change value of the slag in the temperature rising process is delta HARepresents:
ΔHA＝Ht-H298
fifthly, because the metallurgical thermodynamic software data are from experimental acquisition fitting in different periods, system errors exist, and the basis here isIn the NIST Inorganic Crystal Structure Database (ICSD), website: https:// www.nist.gov/srd/nist-standard-reference-database-3 can be given the following thermodynamic equation, which is used for Cp298、H298、Cpt、HtCalculating to obtain enthalpy change value delta H againB. And averaging the enthalpy change value obtained by the calculation of the reaction formula and the enthalpy change value obtained by the calculation of software to obtain an actual enthalpy change value delta H so as to complete the compensation measure of the system error.
CpCaO＝1.048-2.046×104T-2-2.388T-1/2+1.836×106T-3(T＝298～2845K)
CpMgO＝1.516-1.541×104T-2-7.349T-1/2+1.45×104T-3(T＝298～3098K)
In the formula, CpiIs the specific heat capacity value of a substance i in the slag, wherein the substance i comprises CaO and SiO2、MgO、Al2O3Any one of the above; m isiIs the mass of substance i; t is the actual calculated temperature;
further, the second enthalpy change value is calculated as follows:
ΔHB＝∑miΔHi
ΔHiis the substance in the slagi enthalpy change value; deltatrHiIs the enthalpy of crystallization transition of substance i in the slag; deltal sHiIs the enthalpy of solid-liquid transition of substance i; t istrIs the transition temperature; t isMIs the slag melting temperature; t is the actual calculated temperature; Δ HBIs a second enthalpy change value; m isiIs the mass of substance i; s is solid phase crystallization; l is liquid phase crystallization.
Sixth, as seen from the second step, Δ H can be used as heat input during the temperature rise of the slag; in order to simulate the actual production process, adjusting the alkalinity of the slag to obtain a plurality of groups of slag with different alkalinity, and repeatedly executing the steps to obtain actual enthalpy change values of the plurality of groups of slag with different alkalinity; and taking the average value of actual enthalpy change values of a plurality of groups of different alkalinity slags as the total heat Q required by the slag temperature rise stage in J. A percentage decrease (increase) is made to Q, such as 95% Q, 90% Q, 85% Q, 80% Q, 75% Q. And inputting the quality of the slag component again in metallurgical thermodynamic software, setting the temperature range to be 1796-2096K and the step length to be 0.1, and obtaining the corresponding slag temperature after the slag component is matched with 95% Q, 90% Q, 85% Q, 80% Q and 75% Q. A numerical relationship between the heat fluctuation and the temperature change is obtained, and the change range of the temperature along with the heat fluctuation can represent the thermal stability of the slag, wherein the thermal stability is poorer when the change range is larger.
Seventh, temperature T of each basicity slag at constant total heat input Q, respectivelyiCalculating the corresponding viscosity of the following components:
wherein VCR is the slag viscosity change rate etajIs the slag viscosity, and j is a positive integer.
And plotting the VCR values obtained by calculation to obtain a numerical display graph of the thermal stability. The larger the absolute value of the VCR in the image, the worse the thermal stability of the slag.
And (3) finely adjusting the proportion of the main slag components of the blast furnace, repeating the steps, and selecting the slag components with the best thermal stability as the production slag-blending optimization direction of the actual slag.
The fine adjustment of the component ratio comprises fine adjustment of components, for example, the components can also be CSMA-FeO quinary slag, CSMA-FeO-TiO2Hexahydric slag, and the like; fine adjustment of binary alkalinity, wherein the limiting range of R is 0.7-1.4; the magnesium-aluminum ratio is finely adjusted, and the magnesium-aluminum ratio is limited to be 0.3-1.0.
Example (b): blast furnace slag end slag of certain iron works
Firstly, the final slag taken from a blast furnace of a certain iron-making plant is analyzed by tests, and the main chemical components of the slag are determined: 42% mass% CaO and 42% mass% SiO2＝35％、mass％MgO＝8％、mass％Al2O3＝15％。
The main components (CaO, SiO) of the slag2、MgO、Al2O3) Inputting the mass percentages into a reaction balance module of a metallurgy thermodynamic database to obtain the enthalpy value H of the slag under 298K298＝-1438355.2J。
Calculating the enthalpy value H of the slag at the actual production temperature 1773K by using a reaction equilibrium module in metallurgical thermodynamic softwaret＝-1218753.7J,ΔHA＝219601.5J。
Reuse of the associated thermodynamic equation for Cp298、H298、Cpt、HtCalculating to obtain Delta HB219573.2J. For Δ HAAnd Δ HBAnd averaging to obtain the Δ H of 219587.35J, so as to complete the compensation measure for the system error. The slag basicity was adjusted to obtain a plurality of Δ hs, and the average of the plurality of Δ hs was taken as the final Δ H (omitted here).
Further, as can be seen from the second law of thermodynamics, Δ H can be set to Q, which is 219587.35J as a heat input standard of the slag during temperature rise. And (3) increasing and decreasing the percentage of Q: -5% Q ═ 10979.337J, -10% Q ═ 21958.74J, -15% Q ═ 32938.1J, -20% Q ═ 43917.47J, -25% Q ═ 54896.84J. And inputting the slag components again in a reaction balance module of metallurgical thermodynamic software, setting the temperature range to be 1796-2096K and the step length to be 0.1, and obtaining slag temperatures which are respectively 1703.2K, 1691.2K, 1683K, 1676.2K and 1667.4K and can be matched with 95% Q, 90% Q, 85% Q, 80% Q and 75% Q to obtain the slag temperatures of 95% Q, 90% Q, 85% Q, 80% Q and 75% Q.
Then, the slag components were adjusted to change the binary basicity of the slag within a range of R0.8 to 1.3, and as shown in fig. 2, the relationship between the slag basicity and the temperature was observed at different levels after the above Q (i.e., 95% Q, 90% Q, 85% Q, 80% Q, and 75% Q) was constantly input, to judge the thermal stability of the slag.
As shown in FIG. 3, the temperature T of each basicity slag at a constant total heat input Q, respectivelyiThe corresponding viscosities are calculated, for example: the following table shows the slag basicity range, 0.8-1.2.
| Alkalinity of | CaO/％ | SiO2/％ | MgO/％ | Al2O3/％ |
| 0.8 | 34.22 | 42.78 | 8 | 15 |
| 0.9 | 36.47 | 40.53 | 8 | 15 |
| 1 | 38.50 | 38.50 | 8 | 15 |
| 1.1 | 40.33 | 36.67 | 8 | 15 |
| 1.2 | 44.18 | 36.82 | 8 | 11 |
Thus, the calculation of VCR in the following formula is an example: 0.8-1.2 for five groups of slag, then the slag Viscosity Change Rate (VCR) is (viscosity of 0.9-viscosity of 0.8)/viscosity of 0.8, and then plotted against the VCR data, as shown in fig. 3.
Wherein VCR is the slag viscosity change rate etajIs the slag viscosity, and j is a positive integer and represents the slag group number.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (10)
1. A method for evaluating thermal stability of blast furnace slag, characterized by comprising the steps of:
s1: obtaining the quality and production temperature of each component in the slag;
s2: calculating a first enthalpy change value of the slag heating stage based on thermodynamic software;
calculating a second enthalpy change value of the slag heating stage based on a thermodynamic reaction formula;
s3: taking the average value of the first enthalpy variable value and the second enthalpy variable value as an actual enthalpy variable value;
s4: adjusting the alkalinity of the slag to obtain a plurality of groups of slag with different alkalinity, and repeatedly executing the steps S1-S3 to obtain actual enthalpy change values of the plurality of groups of slag with different alkalinity;
s5: based on a second law of thermodynamics, taking the average value of actual enthalpy change values of a plurality of groups of slag with different alkalinity as the total heat required by the slag temperature rise stage;
s6: inputting total heat to the furnace slag, and calculating the change rate of the furnace slag viscosity after the total heat is input along with the change of the furnace slag alkalinity;
among them, the larger the absolute value of the change rate of slag viscosity, the worse the thermal stability of the slag.
2. The method according to claim 1, wherein the viscosity change rate is calculated as follows:
wherein VCR is the slag viscosity change rate etajIs the slag viscosity, and j is a positive integer.
3. The method as claimed in claim 1, wherein the production temperature is in the range of 1200-1600 ℃.
4. The method according to claim 1, wherein the first enthalpy change value is calculated as follows:
inputting the mass of each component in the slag into thermodynamic calculation software, and respectively calculating the enthalpy value H of the slag at the temperature of 298K298And the enthalpy value H of the slag at the production temperature TtSaid first enthalpy change value Δ HA＝Ht-H298。
5. The method according to claim 1, wherein the second enthalpy change value is calculated by:
and inquiring an inorganic crystal structure database according to the mass of each component in the slag and the production temperature to obtain the specific heat capacity of the slag, and calculating a second enthalpy change value by using the specific heat capacity of the slag.
6. The method according to claim 5, wherein the specific heat capacity of the slag is calculated as follows:
CpCaO＝1.048-2.046×104T-2-2.388T-1/2+1.836×106T-3(T＝298～2845K)
CpMgO＝1.516-1.541×104T-2-7.349T-1/2+1.45×104T-3(T＝298～3098K)
in the formula, CpiIs the specific heat capacity value of a substance i in the slag, wherein the substance i comprises CaO and SiO2、MgO、Al2O3Any one of the above; m isiIs the mass of substance i; and T is the actual calculated temperature.
7. The method according to claim 6, wherein the second enthalpy change value is calculated as follows:
ΔHB＝∑miΔHi
ΔHiis the enthalpy change value of substance i in the slag; deltatrHiIs the enthalpy of crystallization transition of substance i in the slag; deltal sHiIs the enthalpy of solid-liquid transition of substance i; t istrIs the transition temperature; t isMIs the slag melting temperature; t is the actual calculated temperature; Δ HBIs a second enthalpy change value; m isiIs the mass of substance i; s is solid phase crystallization; l is liquid phase crystallization.
8. The method according to claim 1, wherein the method further comprises linearly inputting the total heat amount into the slag and calculating a slag temperature change rate during the input of the total heat amount, wherein the larger the absolute value of the slag temperature change rate is, the worse the thermal stability of the slag is.
9. A method of optimizing blast furnace slag, the method comprising:
the thermal stability evaluation method according to any one of claims 1 to 8 is repeated by fine-tuning the slag composition a plurality of times, and the slag composition having the smallest absolute value of the slag viscosity change rate is selected as the optimum slag.
10. The blast furnace slag optimization method of claim 9, wherein the slag composition fine adjustment includes one or more of a component fine adjustment, an alkalinity fine adjustment, and a magnesium-to-aluminum ratio fine adjustment;
wherein the component fine tuning comprises adjusting a component of the slag;
the fine adjustment range of the alkalinity fine adjustment is 0.7-1.4;
the fine adjustment range of the fine adjustment of the magnesium-aluminum ratio is 0.3-1.0.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140224069A1 (en) * | 2013-02-12 | 2014-08-14 | 9255-8444 QUEBEC INC. dba METKEM INNOVATION | Method for the production and the purification of molten calcium aluminate using contaminated aluminum dross residue |
| JP2015048487A (en) * | 2013-08-30 | 2015-03-16 | Ｊｆｅスチール株式会社 | Blast furnace operation method |
| CN106096215A (en) * | 2016-07-28 | 2016-11-09 | 华东师范大学 | A kind of sense of reality fluid simulation method relating to conduction of heat and Dynamic Viscosity |
| CN107132156A (en) * | 2017-05-05 | 2017-09-05 | 西安石油大学 | A kind of analogy method of grain density and particle diameter dynamic change fluid bed |
| CN108559813A (en) * | 2018-06-08 | 2018-09-21 | 北京科技大学 | A kind of titaniferous material furnace retaining Economic Evaluation model |
-
2021
- 2021-03-15 CN CN202110277357.4A patent/CN113051847B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140224069A1 (en) * | 2013-02-12 | 2014-08-14 | 9255-8444 QUEBEC INC. dba METKEM INNOVATION | Method for the production and the purification of molten calcium aluminate using contaminated aluminum dross residue |
| JP2015048487A (en) * | 2013-08-30 | 2015-03-16 | Ｊｆｅスチール株式会社 | Blast furnace operation method |
| CN106096215A (en) * | 2016-07-28 | 2016-11-09 | 华东师范大学 | A kind of sense of reality fluid simulation method relating to conduction of heat and Dynamic Viscosity |
| CN107132156A (en) * | 2017-05-05 | 2017-09-05 | 西安石油大学 | A kind of analogy method of grain density and particle diameter dynamic change fluid bed |
| CN108559813A (en) * | 2018-06-08 | 2018-09-21 | 北京科技大学 | A kind of titaniferous material furnace retaining Economic Evaluation model |
Non-Patent Citations (4)
| Title |
|---|
| AYMEN MESSAADI等: "A new equation relating the viscosity arrhenius temperature and the activation energy for some newtonian classical solvents", JOURNAL OF CHEMISTRY, pages 1 - 12 * |
| 常治宇;张建良;焦克新;宁晓钧;刘增强;: "MnO对低镁含钛炉渣流动性及热力学性质的影响", 钢铁钒钛, vol. 39, no. 03, pages 80 - 85 * |
| 常治宇;焦克新;张建良;宁晓钧;刘增强;: "TiO_2含量对低镁含锰渣的流动性和热力学性质的影响", 武汉科技大学学报, vol. 41, no. 04, pages 247 - 251 * |
| 常治宇;焦克新;张建良;宁晓钧;白兴全;韩旺学;: "Al_2O_3和MgO对炉渣热焓的影响及热力学分析", 冶金能源, vol. 37, no. 04, pages 24 - 28 * |
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