CN102925672A - Method for evaluating economic value of iron ore by using cost of separately calcining molten iron - Google Patents

Abstract

The invention discloses a method for evaluating the economic value of iron ore by using the cost of separately calcining molten iron. The method comprises the following steps: analyzing the contents of TFe, MgO, CaO, Al2O3, SiO2, K, Na, Pb, Zn, As, Sn, P and S in the iron ore; setting the binary basicity R of slags and the contents of Al2O3 and MgO in the slags, and calculating the charged grade of a blast furnace, the contents of related metal oxides in the slags, the S content of the slags, the load of charged alkali metals and the load of other impurities according to the contents of the components in the iron ore; then calculating the proportions of crude fuels, the energy and power consumption, the coke ratio of the blast furnace, the utilization coefficient of the blast furnace, and the As, Sn, P and S contents of molten iron in the process of separately calcining the ore; and according to the obtained data, evaluating the influence coefficients of the yield and quality of the molten iron on the production and cost of the next working procedure, and finally, obtaining the cost of separately calcining the molten iron according to the unit price of the iron ore so as to evaluate the economic value of the iron ore. According to the method disclosed by the invention, the economic value of the iron ore can be fully and effectively evaluated.

Description

The Method of Evaluating the Economic Value of Iron Ore Using the Cost of Single Burning Hot Metal

technical field

The invention relates to the field of sintering, in particular to a method for evaluating the economic value of iron ore by using the cost index of single-sintered molten iron.

Background technique

A reasonable charge structure is the basis for obtaining the maximum benefit of the blast furnace. It contains two concepts: one is that various ores are the most economical, and the other is that the matching technology of various ores is the best. The same is true for sintering, and the structure of raw materials for sintering should also follow this principle. In the current situation of shortage of iron ore resources and various types of iron ores, it is very necessary to evaluate the metallurgical properties and economical performance of various ores. Choosing to use those ores that can bring benefits to the enterprise is the premise of a reasonable furnace charge structure and a reasonable sintering raw material structure. In particular, there are very few lump ore used in blast furnaces at present, so it is necessary to conduct a systematic evaluation from ore, sintering to blast furnace smelting.

Usually, for iron ore for sintering, the concept of "single sintering value" is often introduced in sintering production, that is, when a certain ore is sintered alone, the percentage of iron content in the sintered ore produced under a certain alkalinity is called For the single burn value. The single burning value reflects the grade of sinter produced from this ore. By calculating the cost of raw materials (including the cost of iron ore, fuel, flux, etc.) required to produce 1 ton of sintered ore by burning a certain ore alone, and by comparing the price of each grade of iron (degrees) per ton of sintered ore The cost of ore sintering is high or low.

It is the simplest method to evaluate sintered iron ore powder by single burning value, which reflects the relationship between the price of the ore and the grade of the ore. However, this method of evaluating iron ore by "single burning value" has the following disadvantages: on the one hand, it does not take into account the influence of SiO ₂ , MgO, Al ₂ O ₃ and K, Na, Pb, Zn, S, P, etc. On the other hand, the single sintering value is compared according to the high alkalinity sinter, and acidic materials are added to balance the blast furnace at the end, which will affect the comparison effect, and the cost per ton of iron sinter can not actually reflect the smelting benefits of the blast furnace.

In order to make up for the deficiency of single-burning value evaluation methods, someone proposed an economic value evaluation method for sintered iron ore powder. sinter, calculate its iron grade, chemical composition, total cost and consumption of sinter; secondly, after obtaining the single burning value of self-fluxing sinter, use M.A. Calculate the metallurgical value of single-sintered sinter ore according to the calculation method, that is, the metallurgical value of single-sintered sintered ore is compared with the consumption of single-sintered ore, and the metallurgical value of unit ore is calculated. The metallurgical value of single-sintered sinter minus the cost of single-sintered sinter is the economic value of sintered ore. The economic value of single-sintered sintered ore is compared with the consumption of single-sintered sintered ore to calculate the economic value of unit ore. At present, most iron and steel plants adopt this economic value evaluation method as the evaluation method of iron ore. Its advantage is that it excludes the impact of blast furnace acid charge, and the final economic value index is measured by the cost of molten iron. However, this method still does not consider the influence of gangue components and harmful elements, and only uses alkalinity as the quality requirement of slag.

Due to the sluggish steel market in recent years, the profits of iron and steel enterprises have declined, and even losses, so the optimization of sintering ingredients and blast furnace charge structure optimization has received more and more attention. In the past, the optimization of sintering ingredients was aimed at the lowest sintering cost, and the composition and performance of sintered ore were optimized within a reasonable range through certain sintering conditions. However, in practice, it is found that the reduction of sintering cost does not mean that the cost of molten iron will be reduced accordingly. Due to factors such as the decrease in the utilization factor of the sintering machine, the increase in coke powder and energy consumption, the deterioration of sinter performance, the decrease in grade, and the decrease in slag fluidity, etc. As a result, the utilization factor of the blast furnace will decrease, the coke ratio will increase, and the cost of molten iron will increase instead. Therefore, this requires the idea of optimizing sintering ingredients and blast furnace charge structure to change to aim at the lowest cost of molten iron. Economic evaluation of iron ore is the basis for sintering batching and blast furnace charge structure optimization, and is also the basis for blast furnace to implement low-cost molten iron strategy. Therefore, when evaluating the economic value of iron ore, its direct and indirect impact on the cost of the iron system and its impact on the cost of the next process should be considered comprehensively.

Contents of the invention

In order to make up for the deficiencies of the existing evaluation methods for the economic value of iron ore, the present invention comprehensively considers the influence of each component in the iron ore, and comprehensively considers the single burning value, the cost of molten iron and the impact on the cost of the next process, and is innovative. A method of evaluating the economic value of iron ore by using the cost of single-burning molten iron is proposed.

The invention provides a method for evaluating the economic value of iron ore by using the cost of single-burning molten iron. The method includes the following steps: analyzing the components TFe, SiO ₂ , MgO, CaO, Al ₂ O ₃ , K in the iron ore , Na, Pb, Zn, As, Sn, S, P content; set the binary basicity R of the slag and the content of Al ₂ O ₃ and MgO of the slag, and calculate the blast furnace according to the content of the above components in the iron ore The input grade of the furnace, the relevant metal oxide content of the slag, the S content of the slag, the alkali metal load and other harmful impurity loads of the furnace, and then calculate the ratio of raw material and fuel of the single-fired iron ore, the coke ratio of the blast furnace, and the blast furnace Utilization coefficient, content of As, Sn, S, P in molten iron, etc.; evaluate the impact coefficient of molten iron quality on the production and cost of the next process based on the above data, and finally obtain the cost of single-sintered molten iron according to the ore price to evaluate iron ore sintering economic value.

According to the present invention, the influence of each component of iron ore on the cost of molten iron is as follows: when the other components remain unchanged, the ore grade (that is, TTe) increases by 1%, the coke ratio of the blast furnace decreases by 1.4%, and the utilization factor of the blast furnace increases by 2.1%. , energy and power consumption decreased by 2.1%; in the case of other components unchanged, for every 1% increase in SiO ₂ in the ore, the blast furnace coke ratio increased by 1.2%, the blast furnace utilization factor decreased by 1.8%, and the energy and power consumption increased by 1.8%; When the composition remains unchanged, every 1% increase in CaO or MgO in the ore, the blast furnace coke ratio will decrease by 1%, the blast furnace utilization coefficient will increase by 1.5%, and the energy and power consumption will decrease by 1.5%. For every 1% increase in Al ₂ O ₃ , the coke ratio of the blast furnace increases by 1%, the utilization factor of the blast furnace decreases by 1.5%, and the energy and power consumption increases by 1.5%. For every 0.05% increase in harmful elements, the blast furnace coke ratio will increase by 0.5%, the blast furnace utilization factor will decrease by 1%, and the energy and power consumption will increase by 1%.

According to the present invention, the impact of molten iron on the next process is as follows: every 0.01% increase in the content of As, Sn, P, and S in the molten iron increases the processing cost of the next process by 5%.

According to the present invention, the setting of the binary basicity R of the slag and the content of Al ₂ O ₃ and MgO of the slag can be made according to the charge structure, smelting conditions and production conditions of the blast furnace.

According to the present invention, the relevant metal oxide content of the slag can include the _Al2O3 content and _MgO content of the slag, the alkali metal load into the furnace can include the K load and Na load into the furnace, and the other harmful impurity loads into the furnace can include Zn load, Pb load, S load and P load into the furnace.

According to the method of the present invention, the economic value of sintered iron ore can be comprehensively and effectively evaluated.

Detailed ways

The traditional iron ore sintering evaluation method only considers the requirement of sinter single firing value or basicity balance of blast furnace slag, and completely ignores the influence of ore on the utilization coefficient of each unit in the iron system, the influence of coke ratio, energy and power, and the influence of the gangue. MgO and CaO have beneficial effects on smelting, and harmful components such as S, Al ₂ O ₃ , SiO ₂ , K, Na, Pb, Zn, As, Sn have harmful effects on blast furnace smelting and subsequent production and cost.

According to the present invention, under the condition that the specific furnace charge structure and other smelting conditions of each ironworks remain unchanged, a single ore is sintered and then smelted in a blast furnace. Considering TFe, CaO, MgO, SiO ₂ , The impact of Al ₂ O ₃ , S, P, K, Na, Pb, Zn, As, Sn and other components on the cost of molten iron and the cost of the next process, as well as its impact on the technical and economic indicators of sintering machines, blast furnaces, energy and power consumption, etc., A new method to evaluate the economic value of iron ore is to consider the single burning value, the cost of molten iron and the influence of the quality of molten iron produced from this kind of ore on the cost of the next process.

The invention proposes a brand-new method for evaluating the economic value of iron ore sintering by utilizing the cost of single-sintered molten iron. Specifically, firstly, analyze the content of TFe (total iron), MgO, CaO, Al ₂ O ₃ , SiO ₂ , K, Na, Pb, Zn, As, Sn, S, P, etc. in iron ore; Set the binary basicity R of the slag and the content of Al ₂ O ₃ and MgO in the slag, and then calculate the input grade of the blast furnace, the content of related metal oxides in the slag, and the S content, the alkali metal load into the furnace and other harmful impurity loads, etc., and then calculate the ratio of raw materials and fuels of single-fired iron ore (the ratio of individual ore, limestone, dolomite, and coke powder), blast furnace coke ratio, Blast furnace utilization coefficient, As, Sn, S, P content of molten iron, etc.; finally, according to the above data, evaluate the influence coefficient of molten iron quality on the production and cost of the next process, and obtain the cost of single-sintered molten iron according to the unit price of iron ore, Used to evaluate the economic value of iron ore.

Specifically, according to the present invention, the binary basicity R of the slag and the respective contents of Al ₂ O ₃ and MgO in the slag are set according to the existing charge structure, smelting conditions and actual production conditions of the blast furnace. Here, under the teaching of the present invention, those skilled in the art can use existing methods to set the binary basicity R of the slag and the respective contents of Al ₂ O ₃ and MgO in the slag according to the actual situation.

According to the present invention, after setting the binary basicity R of the slag and the respective contents of Al ₂ O ₃ and MgO of the slag, the TFe (full iron), SiO ₂ , MgO, and CaO in the analyzed iron ore are used to , Al ₂ O ₃ , K, Na, Pb, Zn, As, Sn, S, P, etc., the following data are calculated through a preset computer program: the furnace grade of the blast furnace; the consumption of various raw materials of the blast furnace , for example: the production of one ton of molten iron consumes 1.92 tons of ore, 0.4 tons of coke and various consumptions such as limestone, dolomite, coke powder, energy and power; the metal oxide content of slag, for example, the Al ₂ O ₃ content of slag and MgO content; S content of slag; alkali metal load into the furnace, such as K load and Na load into the furnace; impurity load into the furnace, such as Zn, Pb, S, P and other impurity loads into the furnace. Here, under the teaching of the present invention, those skilled in the art can choose an appropriate computer program to perform the calculation of the above data. In addition, it can also calculate the blast furnace coke ratio, blast furnace utilization coefficient, As, Sn, S, P content of molten iron when a certain iron ore is sintered separately and put into the furnace for smelting.

Finally, according to the calculated grade of the blast furnace, the content of related metal oxides in the slag, the S content of the slag, the load of alkali metals and other harmful impurities in the furnace, and the calculated raw-fuel ratio of single-sintered iron ore , blast furnace coke ratio, blast furnace utilization coefficient, As, Sn, S, and P contents of molten iron, comprehensively consider the impact of iron ore on blast furnace smelting, production and cost of the next process, and evaluate the impact of molten iron quality on the production and cost of the next process Influence coefficient, and then according to the consumption of various raw materials of the blast furnace and the price of iron ore, the cost of single-burning molten iron is calculated to evaluate the economic value of iron ore. Here, under the teaching of the present invention, those skilled in the art can use an appropriate method to calculate the cost of single-sintered molten iron according to the actual situation.

In the present invention, the concept of the cost of single-sintered molten iron is explained as follows: under the condition that the existing charge structure and other smelting conditions remain unchanged, a single ore is sintered and then smelted in a blast furnace. , SiO ₂ , MgO, K, Na, Pb, Zn, As, S, P, Sn and other components on the cost of molten iron and the production and cost of the next process, as well as its impact on the sintering machine, blast furnace technical and economic indicators, energy and power consumption, The impact of coke powder and coke consumption on the cost of molten iron is considered as "single-sintered molten iron cost" by comprehensively considering the single-burning value, the cost of molten iron and the impact on the cost of the next process.

In the present invention, the cost of single-sintered molten iron includes the single-sintered value and the cost of molten iron and its impact on the cost of the next process. Specifically, the single-sintered value includes various beneficial or harmful effects of sintered ore obtained when a certain ore is sintered separately. The value of components, the cost of molten iron includes iron ore, coke, various auxiliary materials, energy and power, workers' wages, equipment maintenance and depreciation required for the production of molten iron.

In the present invention, the impact of each component of iron ore on the cost of molten iron and the impact of molten iron on the next process are as follows: when other components remain unchanged, the ore grade increases by 1%, the coke ratio of the blast furnace decreases by 1.4%, and the utilization factor of the blast furnace Increase by 2.1%, energy and power consumption decreased by 2.1%; in the case of other components unchanged, every 1% increase in SiO ₂ in ore, blast furnace coke ratio increased by 1.2%, blast furnace utilization coefficient decreased by 1.8%, energy and power consumption increased by 1.8% ; When other components remain unchanged, every 1% increase in CaO or MgO in the ore, the blast furnace coke ratio will decrease by 1%, the blast furnace utilization factor will increase by 1.5%, and the energy and power consumption will decrease by 1.5%; , when the Al ₂ O ₃ in the ore increases by 1%, the blast furnace coke ratio increases by 1%, the blast furnace utilization coefficient decreases by 1.5%, and the energy and power consumption increases by 1.5%. For every 0.05% increase in Pb, Zn and other harmful elements, the blast furnace coke ratio will increase by 0.5%, the blast furnace utilization factor will decrease by 1%, and the energy and power consumption will increase by 1%. The processing cost will increase by 5%.

The method for evaluating the economic value of iron ore by using the cost of single-burning molten iron according to the present invention will be described below in conjunction with specific exemplary embodiments.

The economic value of imported iron ore powder (here is Australian ore), Pingchuan limonite and Changdu iron ore which can be purchased from the market is evaluated. First, send the iron ore to a laboratory or analysis center to analyze the composition or element content in the aforementioned three iron ores, and the results are shown in Table 1 below.

Table 1 Element content in various iron ores

Then, according to the existing charge structure, smelting conditions and actual production conditions of the blast furnace, the binary basicity R of the slag and the contents of Al ₂ O ₃ and MgO in the slag were set to 1.15, 13.5%, and 9.5%, respectively. Then, according to Table 1 and the set binary basicity R of the slag and the contents of Al ₂ O ₃ and MgO in the slag, under the condition that the structure of the blast furnace charge and other smelting conditions remain unchanged, the above three The input data and molten iron data of the iron ore blast furnace are shown in Table 2 and Table 3 below, respectively.

Table 2 Furnace input data of various iron ore blast furnaces

Table 3 Hot metal data of various iron ore blast furnaces

Then, according to the data in Table 2 and Table 3, the influence coefficient of molten iron quality on the production and cost of the next process is evaluated, so as to obtain the cost of single-sintered molten iron to evaluate the economic value of iron ore sintering.

Table 4 The cost of single-burning molten iron for the above-mentioned various ores

Ore species Imported ore Qamdo Iron Ore Hirakawa Limonite Single-burning hot metal cost (yuan/ton) 2539.52 2360.34 2434.73

Through the analysis of the three kinds of iron ores, it can be seen that although most of the components of the imported powder (Australian mine) and Qamdo iron ore are similar, the SiO ₂ content is quite different, and the price is still cheap. Therefore, the cost of single-burning molten iron is calculated. Qamdo iron ore is about 179 yuan/ton lower than imported ore; if you use the previous method of single burning value for comparison, the two can be substituted, which does not reflect the SiO ₂ and price advantages of Qamdo iron ore. However, due to the low grade (TFe) of Pingchuan limonite, it greatly affects the coke ratio and utilization coefficient of the blast furnace, but its price is relatively low. According to the calculation of its single-burning molten iron cost, its single-burning molten iron cost is 2434.73 yuan/ton, It is about 104 yuan/ton lower than imported ore, and only about 76 yuan/ton higher than Changdu mine, which largely reflects the price advantage of Pingchuan limonite. Hirakawa limonite will not be used if the iron ore is evaluated using the previous single burning value or only its composition. At present, the applicant of this application has greatly reduced the cost of molten iron by using low-priced limonite, and the cost of molten iron per ton has dropped to more than 200 yuan/ton, which provides a strong basis for us to reduce production costs and turn losses into profits .

Therefore, according to the present invention, it is different from the previous method that only considers the single burning value of iron ore or the cost of molten iron using this ore and part of the chemical composition. , by comprehensively considering the impact of TFe, CaO, MgO, SiO ₂ , K, Na, Pb, Zn, As, S, P, Sn and other elements in iron ore on the economic value of iron ore, the single burning value and molten iron cost Considering comprehensively, the producibility of ore is also taken into consideration, that is, the economic value of sintered iron ore can be fully evaluated by combining the optimized sintering ingredients and the structure of the blast furnace charge. In addition, the method of the present invention also takes into account the impact of iron ore on various technical and economic indicators of sintering and blast furnaces, such as the impact on utilization coefficient, coke, coke powder, and other energy and power consumption, and also considers the impact on the next process production and Therefore, the economic evaluation of sintered iron ore can be effectively carried out.

While the present invention has been particularly shown and described with reference to exemplary embodiments of the present invention, those skilled in the art should understand that, without departing from the spirit and scope of the present invention defined by the claims and their equivalents, , various changes in form and details may be made herein.

Claims (5)

1. A method utilizing single burning molten iron cost to evaluate the economic value of iron ore is characterized in that said method comprises the following steps and content: Analyze the content of TFe, SiO ₂ , MgO, CaO, Al ₂ O ₃ , K, Na, Pb, Zn, As, Sn, S, P in iron ore; Set the binary basicity R of the slag and the content of Al ₂ O ₃ and MgO in the slag, and calculate the grade of the blast furnace, the content of related metal oxides in the slag, and the S content in the slag according to the content of the above components in the iron ore , alkali metal load and other impurity loads into the furnace, and then calculate the ratio of raw material and fuel, energy and power consumption, blast furnace coke ratio, blast furnace utilization coefficient, As, Sn, P, S of molten iron content; According to the above data, the influence coefficient of molten iron production quality on the cost of the next process is evaluated, and finally the cost of single-burning molten iron is obtained according to the unit price of iron ore to evaluate the economic value of iron ore. 2. method according to claim 1 is characterized in that in the iron ore, each composition is as follows on the influence of molten iron cost: When other components remain unchanged, for every 1% increase in ore grade, the blast furnace coke ratio will decrease by 1.4%, the blast furnace utilization factor will increase by 2.1%, and the energy and power consumption will decrease by 2.1%; In the case of other components remaining unchanged, for every 1% increase in SiO ₂ in the ore, the blast furnace coke ratio increases by 1.2%, the blast furnace utilization factor decreases by 1.8%, and the energy and power consumption increases by 1.8%; When other components remain unchanged, for every 1% increase in CaO or MgO in the ore, the blast furnace coke ratio will decrease by 1%, the blast furnace utilization factor will increase by 1.5%, and the energy and power consumption will decrease by 1.5%; In the case of other components remaining unchanged, for every 1% increase in Al ₂ O ₃ in the ore, the blast furnace coke ratio increases by 1%, the blast furnace utilization factor decreases by 1.5%, and the energy and power consumption increases by 1.5%; When other components remain unchanged, every 0.05% increase in the harmful elements K, Na, Pb, and Zn in the ore will increase the blast furnace coke ratio by 0.5%, decrease the blast furnace utilization factor by 1%, and increase energy and power consumption by 1%. 3. The method according to claim 1, characterized in that the impact of molten iron on the next process is as follows: the As, Sn, P, and S contents in the molten iron increase by 0.01%, and the processing cost of the next process increases by 5%. 4. The method according to claim 1, characterized in that the setting of the binary basicity R of the slag and the content of _Al2O3 and MgO of the slag is made according to the charge structure, smelting _conditions and production conditions of the blast furnace . 5. The method according to claim 1, wherein the metal oxide content of the slag comprises the _Al2O3 content and the _MgO content of the slag, the alkali metal load entering the furnace comprises the K load and the Na load entering the furnace, The impurity load includes Zn load, Pb load, S load and P load into the furnace.