A method for simulating the effect of alkali metal and fluorine cyclic enrichment on the reducibility of blast furnace iron-containing charge

Abstract

The invention discloses a method for simulating the influence of cyclic enrichment of alkali metals and fluorine on the reducibility of iron-containing charge in the blast furnace. Based on the premise that the alkali load and fluorine load of Baotou Steel's blast furnace are high and the cyclic enrichment in the furnace is serious, a method for determining the influence of cyclic enrichment of alkali metals and fluorine on the reducibility of comprehensive charge is proposed, and the reducibility of the charge measured in the case of no alkali metal and fluorine enrichment is compared, so as to propose a charge structure more suitable for the smelting conditions of cyclic enrichment of alkali metals and fluorine in the blast furnace.

Description

Technical Field

[0001] The invention relates to the technical field of ironmaking raw material agglomeration, and in particular to a method for simulating the influence of alkali metal and fluorine cyclic enrichment in a blast furnace on the reducibility of iron-containing furnace charge in the blast furnace. Background Art

[0002] Because the Bayan Obo iron concentrate used in Baotou Steel's blast furnace ironmaking has high alkali metal and fluorine content, the alkali load of Baotou Steel's blast furnace can reach 4.5kg / t iron. The alkali metals circulate and enrich in the blast furnace, which has a significant destructive effect on the blast furnace charge and coke. Therefore, it is a difficult problem in Baotou Steel's blast furnace smelting to study the effect of alkali metal cyclic enrichment on the metallurgical properties of blast furnace iron-containing charge and further develop iron-containing charge that can resist the destructive effect of alkali metal and fluorine cyclic enrichment. Under the conditions of reducibility determination, this project studied the effect of alkali metal and fluorine cyclic enrichment on the reducibility of 18 groups of charge in the laboratory, and compared the reducibility of the charge measured without alkali metal and fluorine enrichment, and proposed a more suitable charge structure that is more in line with the blast furnace alkali metal and fluorine cyclic enrichment smelting conditions. Summary of the invention

[0003] The purpose of the present invention is to provide a method for simulating the influence of cyclic enrichment of alkali metals and fluorine on the reducibility of iron-containing charge in the blast furnace. Based on the premise that the alkali load and fluorine load of Baosteel blast furnace are high and the cyclic enrichment in the furnace is serious, a method for laboratory determination of the influence of cyclic enrichment of alkali metals and fluorine on the reducibility of comprehensive charge under reducing conditions is established, and the quantitative determination of the ability of different types of charge structures to resist alkali metal and fluorine damage is achieved, which can provide a technical basis for the reasonable selection of charge structure for blast furnaces under high alkali metal and fluorine conditions.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The present invention provides a method for simulating the influence of alkali metal and fluorine cyclic enrichment in a blast furnace on the reducibility of iron-containing charge in the blast furnace, comprising:

[0006] The reagents for adding alkali metals to the comprehensive charge of the blast furnace are K2CO3, Na2CO3 and CaF2, and the comprehensive charge for the reducibility determination is set to 500g. According to the multiples of the cyclic enrichment of alkali metals and fluorine in the reduction zone of the blast furnace, the amount of K2CO3, Na2CO3 and CaF2 added is weighed by accurate measurement;

[0007] The enrichment multiples of alkali metals and fluorine in the blast furnace reduction zone are the actual measured values ​​of blast furnace sampling, among which the F content is 0.13 times that brought into the charge, the K2O content is 3.06 times that brought into the charge, and the Na2O content is 0.199 times that brought into the charge;

[0008] Add precisely measured K2CO3, Na2CO3 and CaF2 into water to prepare a solution, and then soak 500g of comprehensive iron-containing furnace charge in it;

[0009] The soaked samples were dried in an oven to precipitate K2CO3, Na2CO3 and CaF2 on the surface of the comprehensive iron-containing charge, which more directly simulated the state of alkali metals cyclically enriched on the surface of the iron-containing charge in the blast furnace;

[0010] Use the national standard reducibility test device to test the reducibility of the dried comprehensive furnace charge;

[0011] The influence of cyclic enrichment of alkali metals and fluorine on the comprehensive charge reducibility is compared with the reducibility of the charge measured without alkali metal and fluorine enrichment.

[0012] Furthermore, based on the comparison of the reducibility of the charge measured without alkali metal and fluorine enrichment, a charge structure more suitable for blast furnace alkali metal and fluorine cycle enrichment smelting conditions is proposed.

[0013] Compared with the prior art, the beneficial technical effects of the present invention are:

[0014] Based on the premise that Baosteel's blast furnace has high alkali load and fluorine load and serious circulating enrichment in the furnace, a method for determining the influence of circulating enrichment of alkali metals and fluorine on the comprehensive charge reducibility is proposed, and compared with the reducibility of the charge measured in the absence of alkali metal and fluorine enrichment, so as to propose a charge structure that is more suitable for the blast furnace alkali metal and fluorine circulating enrichment smelting conditions. DETAILED DESCRIPTION

[0015] The specific embodiments of the present invention are further described below by way of examples, but the specific embodiments of the present invention are not limited to the following examples.

[0016] The comprehensive charge structure of each embodiment is shown in Table 1, the comprehensive charge structure alkali leaching and fluorine leaching scheme of each embodiment is shown in Table 2, and the reducibility measurement results are shown in Table 3.

[0017] Table 1 Furnace charge structure scheme of each embodiment

[0018]

[0019]

[0020] Among them, "self-produced" refers to Bayan Obo iron ore concentrate, and "within the district" refers to purchased iron ore concentrate.

[0021] Table 2 Alkali and fluorine addition schemes for charge structure of each embodiment

[0022]

[0023]

[0024] Table 3 Reducibility test results

[0025]

[0026] From Table 2 and Table 3, we can see that:

[0027] When 45% of Bayan Obo iron concentrate was added to the furnace, only the 3# charge structure had the best ability to resist the reaction of alkali metals and F with the surface of the granular charge to form a liquid phase and produce adhesives, and had the best anti-powdering ability, ensuring the reducibility of the reduction channel and the comprehensive charge. When 40% of Bayan Obo iron concentrate was added to the furnace, only the 11# charge structure had the best ability to resist the reaction of alkali metals and F with the surface of the granular charge to form a liquid phase and produce adhesives, and had the best anti-powdering ability, ensuring the reducibility of the reduction channel and the comprehensive charge. When 35% of Bayan Obo iron concentrate was added to the furnace, the 15#-18# charge structures had good ability to resist the reaction of alkali metals and F with the surface of the granular charge to form a liquid phase and produce adhesives, and had good anti-powdering ability, ensuring the reducibility of the reduction channel and the comprehensive charge.

[0028] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for simulating the effect of alkali metal and fluorine cyclic enrichment on the reducibility of iron-containing charge in a blast furnace, characterized in that: include: The reagents for adding alkali metals to the comprehensive charge of the blast furnace are K2CO3, Na2CO3 and CaF2, and the comprehensive charge for the reducibility determination is set to 500g. According to the multiples of the cyclic enrichment of alkali metals and fluorine in the reduction zone of the blast furnace, the amount of K2CO3, Na2CO3 and CaF2 added is weighed by accurate measurement; The enrichment multiples of alkali metals and fluorine in the blast furnace reduction zone are the actual measured values ​​of blast furnace sampling, among which the F content is 0.13 times that brought into the charge, the K2O content is 3.06 times that brought into the charge, and the Na2O content is 0.199 times that brought into the charge; Add precisely measured K2CO3, Na2CO3 and CaF2 into water to prepare a solution, and then soak 500g of comprehensive iron-containing furnace charge in it; The soaked samples were dried in an oven to precipitate K2CO3, Na2CO3 and CaF2 on the surface of the comprehensive iron-containing charge, which more directly simulated the state of alkali metals cyclically enriched on the surface of the iron-containing charge in the blast furnace; Use the national standard reducibility test device to test the reducibility of the dried comprehensive furnace charge; The influence of cyclic enrichment of alkali metals and fluorine on the comprehensive charge reducibility is compared with the reducibility of the charge measured without alkali metal and fluorine enrichment.

2. The method for simulating the effect of cyclic enrichment of alkali metals and fluorine in a blast furnace on the reducibility of iron-containing charge in a blast furnace according to claim 1, characterized in that: According to the comparison results of the reducibility of the charge measured without alkali metal and fluorine enrichment, a suitable charge structure is proposed that is more suitable for the blast furnace alkali metal and fluorine circulating enrichment smelting conditions.

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