Evaluation method of electric furnace deep reduction smelting vanadium titano-magnetite metallized pellet process

Abstract

The invention relates to the technical field of ferrous metallurgy, in particular to an evaluation method of a process for deep reduction smelting of vanadium titano-magnetite metallized pellets in an electric furnace, the slag iron quality and the process are graded through the recovery rate of valuable elements, meanwhile, the economic score of the process is calculated through the components and temperature of molten iron, the calculation is simple, and the method is easy to implement. The evaluation indexes are simple and rapid, the quality level of melt separation slag and vanadium-containing molten iron obtained after deep reduction of the vanadium titano-magnetite metallized pellet electric furnace, the technical level of the deep reduction technology and the economical efficiency level of the technology can be clearly and objectively evaluated, and a user can comprehensively evaluate the technical level and the economical efficiency of the technology. And a certain item can be evaluated independently, and the method can be used flexibly according to actual conditions. The evaluation method comprehensively considers the influence of factors such as carbon, sulfur, phosphorus, vanadium and temperature of the molten iron, can more comprehensively and objectively evaluate the deep reduction melt vanadium-containing molten iron, and has good innovativeness and practicability.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgy, and in particular to an evaluation method for a process for deep reduction smelting of vanadium-titanium magnetite metallized pellets in an electric furnace. Background Art

[0002] At present, ironmaking technology is mainly based on the long blast furnace process. During the blast furnace smelting of vanadium-titanium magnetite, the recovery rate of valuable element iron is about 95% to 97%, the recovery rate of vanadium in molten iron is about 75% to 80%, and the recovery rate of titanium in slag is about 97% to 98%. There are problems such as low recovery rate of vanadium element. Although the recovery rate of titanium element is relatively high, the blast furnace slag after recovery has a low titanium grade due to the addition of solvent to adjust the slag, which makes it difficult to have economic resource utilization. Using the non-blast furnace process of vertical furnace-electric furnace deep reduction to smelt vanadium-titanium magnetite can effectively improve the recovery rate of vanadium and the grade of titanium in slag, and improve the economic efficiency of titanium resource utilization, thereby achieving comprehensive resource recovery and utilization of the three valuable elements of iron, vanadium and titanium.

[0003] At present, the evaluation of molten iron quality in blast furnaces is mainly based on the classification of molten iron composition, but the composition of vanadium-containing molten iron from deep reduction in electric furnaces is quite different from that of blast furnace molten iron, and is not suitable for this evaluation method. The molten iron from deep reduction in electric furnaces contains higher vanadium, lower carbon, sulfur and phosphorus than blast furnace molten iron, and is more suitable for smelting special steel grades with high added value. The quality and economic evaluation method of blast furnace molten iron is difficult to reflect its true value, and the molten slag after deep reduction has better application prospects than high-furnace slag. It is urgent to create an evaluation standard to comprehensively evaluate the deep reduction process of electric furnaces and the quality of slag iron. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide an evaluation method for the process of deep reduction smelting of vanadium-titanium magnetite metallized pellets in an electric furnace. The method has simple calculations and simple and quick evaluation indicators, and can clearly and objectively evaluate the molten slag after deep reduction of vanadium-titanium magnetite metallized pellets in an electric furnace, the quality level of vanadium-containing molten iron, the technical and technological level of the deep reduction process itself, and the economic level of the process.

[0005] The present invention provides an evaluation method for an electric furnace deep reduction smelting vanadium-titanium magnetite metallized pelletizing process, including at least one of a technical score calculation and an economic score calculation;

[0006] The technical score calculation includes:

[0007] The calculation formula of vanadium recovery rate is shown in formula (1):

[0008] Vanadium recovery rate = total mass of vanadium-containing molten iron × mass fraction of vanadium in molten iron / (total mass of vanadium-containing molten iron × mass fraction of vanadium in molten iron + total mass of molten slag × mass fraction of vanadium in molten slag) formula (1);

[0009] The calculation formula of titanium recovery rate is shown in formula (2):

[0010] Titanium recovery rate = total mass of molten slag × mass fraction of titanium in molten slag / (total mass of vanadium-containing molten iron × mass fraction of titanium in molten iron + total mass of molten slag × mass fraction of titanium in molten slag) formula (2);

[0011] The calculation formula of iron recovery rate is shown in formula (3):

[0012] Iron recovery rate = total mass of vanadium-containing molten iron × mass fraction of iron in molten iron / (total mass of vanadium-containing molten iron × mass fraction of iron in molten iron + total mass of molten slag × ferrous content in molten slag × mass fraction of iron in ferrous iron) formula (3);

[0013] Classification of vanadium-containing molten iron: 80% to 85% of vanadium recovery rate and 97% to 98% of iron recovery rate are qualified products; 80% to 85% of vanadium recovery rate and more than 98% of iron recovery rate, or more than 85% of vanadium recovery rate and more than 97% to 98% of iron recovery rate are good products; more than 85% of vanadium recovery rate and more than 98% of iron recovery rate are excellent products;

[0014] Slag classification: The recovery rate of titanium element in slag is 88% to 90% for qualified products, the recovery rate of titanium element in slag is 90% to 92% (inclusive) for good products, and the recovery rate of titanium element in slag is greater than 92% for excellent products;

[0015] When the slag and iron are classified as unqualified, qualified, first-class, and superior, the scoring rules are the same, which are recorded as -10, 30, 40, and 50 respectively. The sum of the scores of slag and iron quality evaluation is the process score. The process evaluation is:

[0016] Process score Rating <60 Failure 60 or 70 qualified 80 or 90 good 100 excellent

[0017] The economic efficiency score calculation includes:

[0018] Calculate the influence of sulfur (S), phosphorus (P), vanadium (V), carbon (C) and molten iron temperature on the value of molten iron. The influence of sulfur (S) and phosphorus (P) on the value of molten iron is calculated based on the actual removal cost. The influence of carbon, vanadium and molten iron temperature on the value of molten iron is calculated according to the following formulas respectively;

[0019] The calculation formula of the influence value of molten iron S is shown in formula (4):

[0020] Molten iron S impact value = (molten iron S content - molten steel target S content) × desulfurization cost, yuan / t formula (4);

[0021] The calculation formula of the influence value of molten iron P is shown in formula (5):

[0022] Hot metal P impact value = (hot metal P content - molten steel target P content) × desulfurization cost, yuan / t (formula (5));

[0023] The calculation formula of the influence value of molten iron V is shown in formula (6):

[0024] Molten iron V impact value = (molten iron V content - molten iron V content after vanadium extraction) ÷ 102 × 182 × vanadium recovery rate × (vanadium pentoxide market price - vanadium pentoxide production cost) ÷ tax rate, yuan / t formula (6);

[0025] The calculation formula of the influence value of molten iron C is shown in formula (7):

[0026] Molten iron C impact value = (molten iron C content - molten steel target C content) / weighted average carbon content of process fuel × weighted average price of process fuel, yuan / t formula (7);

[0027] The calculation formula of the molten iron temperature influence value is shown in formula (8):

[0028] (molten iron temperature - molten steel temperature) × molten iron specific heat capacity × electricity price / (3600 × electric furnace thermal efficiency), yuan / t

[0029] Formula (8);

[0030] Scoring rules:

[0031] Before calculation, select the reference molten iron composition and temperature, or use the specified blast furnace molten iron composition and temperature as the reference value;

[0032] According to formula (4) to formula (8), the influence values ​​of the corresponding factors of the base molten iron and the molten iron are calculated respectively, and then the influence value of the molten iron is subtracted from the influence value of the base molten iron, and the absolute value is taken as the value of the molten iron compared with the base molten iron;

[0033] Single economic efficiency score D = the value of the single factor of molten iron compared with the benchmark molten iron / max (the corresponding single factor's molten iron impact value, the benchmark molten iron impact value) × 100 (9);

[0034] The total economic score P = (molten iron vanadium score + molten iron temperature score + molten iron sulfur score + molten iron score + molten iron carbon score) / 5 (10).

[0035] The present invention scores and rates the slag quality and process by the recovery rate of valuable elements, and calculates the economic score of the process by the composition and temperature of molten iron. The calculation is simple, and the evaluation index is simple and fast. The molten slag after deep reduction of vanadium-titanium magnetite metallized pellets in an electric furnace, the quality level of vanadium-containing molten iron, the technical level of the deep reduction process itself, and the economic level of the process can be clearly and objectively evaluated. The user can make a comprehensive evaluation of the technical level and economy of the process, or evaluate a certain item separately, and can use it flexibly according to actual conditions. This evaluation method comprehensively considers the influence of factors such as carbon, sulfur, phosphorus, vanadium and temperature in molten iron, and can evaluate the deep reduction molten vanadium-containing molten iron more comprehensively and objectively, and has good innovation and practicality. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The present invention provides an evaluation method for the process of deep reduction smelting vanadium-titanium magnetite metallized pellets in an electric furnace, by calculating the recovery rates of three valuable elements, namely iron, vanadium and titanium, and evaluating the slag iron generated in the process of deep reduction smelting vanadium-titanium magnetite metallized pellets in an electric furnace according to the element recovery rates, and then evaluating the deep reduction process, which is recorded as a technical score. Then, the value of the molten iron is evaluated based on the valuable elements and residual elements in the molten iron, which is recorded as an economic score.

[0038] Specifically, it includes at least one of a technical score calculation and an economic score calculation;

[0039] The technical score calculation includes:

[0040] The calculation formula of vanadium recovery rate is shown in formula (1):

[0041] Vanadium recovery rate = total mass of vanadium-containing molten iron × mass fraction of vanadium in molten iron / (total mass of vanadium-containing molten iron × mass fraction of vanadium in molten iron + total mass of molten slag × mass fraction of vanadium in molten slag) Formula (1);

[0042] The calculation formula of titanium recovery rate is shown in formula (2):

[0043] Titanium recovery rate = total mass of molten slag × mass fraction of titanium in molten slag / (total mass of vanadium-containing molten iron × mass fraction of titanium in molten iron + total mass of molten slag × mass fraction of titanium in molten slag) Formula (2);

[0044] The calculation formula of iron recovery rate is shown in formula (3):

[0045] Iron recovery rate = total mass of vanadium-containing molten iron × mass fraction of iron in molten iron / (total mass of vanadium-containing molten iron × mass fraction of iron in molten iron + total mass of molten slag × ferrous content in molten slag × mass fraction of iron in ferrous iron) Formula (3);

[0046] Classification of vanadium-containing molten iron: 80% to 85% of vanadium recovery rate and 97% to 98% of iron recovery rate are qualified products; 80% to 85% of vanadium recovery rate and more than 98% of iron recovery rate, or more than 85% of vanadium recovery rate and more than 97% to 98% of iron recovery rate are good products; more than 85% of vanadium recovery rate and more than 98% of iron recovery rate are excellent products;

[0047] Slag classification: The recovery rate of titanium element in slag is 88% to 90% for qualified products, the recovery rate of titanium element in slag is 90% to 92% (inclusive) for good products, and the recovery rate of titanium element in slag is greater than 92% for excellent products;

[0048] When the slag and iron are classified as unqualified, qualified, first-class, and superior, the scoring rules are the same, which are recorded as -10, 30, 40, and 50 respectively. The sum of the scores of slag and iron quality evaluation is the process score. The process evaluation is:

[0049] Process score Rating <60 Failure 60 or 70 qualified 80 or 90 good 100 excellent

[0050] During the evaluation process, the quality of slag and iron is first evaluated by calculation and scored, and then the scores of slag and iron are added together, and the deep reduction process is evaluated according to Table 1.

[0051] The economic efficiency score calculation includes:

[0052] Calculate the influence of sulfur (S), phosphorus (P), vanadium (V), carbon (C) and molten iron temperature on the value of molten iron. The influence of sulfur (S) and phosphorus (P) in molten iron on the value of molten iron is calculated based on the actual removal cost. The influence of carbon, vanadium and molten iron temperature on the value of molten iron is calculated according to the following formulas.

[0053] The calculation formula of the influence value of molten iron S is shown in formula (4):

[0054] Molten iron S impact value = (molten iron S content - molten steel target S content) × desulfurization cost, yuan / t Formula (4);

[0055] The calculation formula of the influence value of molten iron P is shown in formula (5):

[0056] Hot metal P impact value = (hot metal P content - molten steel target P content) × desulfurization cost, yuan / t Formula (5);

[0057] The calculation formula of the influence value of molten iron V is shown in formula (6):

[0058] Molten iron V impact value = (molten iron V content - molten iron V content after vanadium extraction) ÷ 102 × 182 × vanadium recovery rate × (vanadium pentoxide market price - vanadium pentoxide production cost) ÷ tax rate, yuan / t formula (6);

[0059] The calculation formula of the influence value of molten iron C is shown in formula (7):

[0060] Molten iron C impact value = (molten iron C content - molten steel target C content) / weighted average carbon content of process fuel × weighted average price of process fuel, yuan / t Formula (7);

[0061] Among them, regarding the weighted average carbon content of process fuels and the weighted average price of process fuels, the fuels used in the process may be a single type or multiple types, and each type has a corresponding usage ratio and unit price. This is a weighted average carbon content and price calculated based on the usage ratio and chemical composition.

[0062] The calculation formula of the molten iron temperature influence value is shown in formula (8):

[0063] (molten iron temperature - molten steel temperature) × molten iron specific heat capacity × electricity price / (3600 × electric furnace thermal efficiency), yuan / t

[0064] Formula (8);

[0065] Scoring rules:

[0066] Before calculation, select the reference molten iron composition and temperature, or use the specified blast furnace molten iron composition and temperature as the reference value;

[0067] According to formula (4) to formula (8), the influence values ​​of the corresponding factors of the reference molten iron and the molten iron are calculated respectively, and then the influence value of the reference molten iron is subtracted from the influence value of the molten iron, and the absolute value is taken (the influence of molten iron V and temperature is negative, but since it has an improving effect on the value of the molten iron, the absolute value is taken) as the value of the molten iron compared with the reference molten iron;

[0068] Single economic score D = the value of the single factor of molten iron compared with the benchmark molten iron / max (the corresponding single factor's molten iron impact value, the benchmark molten iron impact value) × 100 formula (9);

[0069] Formula (9) can also be written as:

[0070] Single economic score D = the value of the single factor of molten iron compared with the benchmark molten iron / (the corresponding single factor's molten iron impact value or the benchmark molten iron impact value (the larger of the two)) × 100

[0071] Formula (9);

[0072] The total economic score P = (molten iron vanadium score + molten iron temperature score + molten iron sulfur score + molten iron score + molten iron carbon score) / 5 Formula (10).

[0073] Through the above two parts of scoring, the deep reduction process of electric furnace smelting can be evaluated more comprehensively.

[0074] In order to further illustrate the present invention, an evaluation method for an electric furnace deep reduction smelting vanadium-titanium magnetite metallized pelletizing process provided by the present invention is described in detail below in conjunction with examples, but it should not be construed as limiting the scope of protection of the present invention.

[0075] Example

[0076] The slag iron composition and slag iron ratio of Examples 1 to 5 and the content of each element in molten iron are shown in Table 2. In Table 2, the slag iron ratio refers to the amount of slag corresponding to 1 t of molten iron.

[0077] Table 2 Slag iron composition and slag iron ratio of Examples 1 to 5 and the content of each element in molten iron

[0078]

[0079]

[0080] According to formula (1) to formula (3) and Table 2, the slag quality score and process score are obtained, as shown in Table 3.

[0081] Table 3 Slag quality score and process score

[0082]

[0083] As can be seen from Table 3, the present invention scores and rates the slag quality and process by the recovery rate of valuable elements. The calculation is simple, and the evaluation index is simple and fast. It can clearly and objectively evaluate the molten slag after deep reduction of vanadium-titanium magnetite metallized pellets in an electric furnace, the quality level of vanadium-containing molten iron, and the process level of the deep reduction process itself.

[0084] The economic evaluation indexes of molten iron are shown in Table 4:

[0085] The blast furnace molten iron is selected as the benchmark for calculation.

[0086] Table 4 Evaluation indexes of molten iron economy

[0087]

[0088]

[0089] The cost of molten iron desulfurization is calculated at 0.8 yuan per 0.001% S, and the cost of dephosphorization is calculated at 0.7 yuan per 0.001% P.

[0090] The vanadium recovery rate is 64%, V 2 O 5 The market tax-inclusive price is 100,000 yuan / t, the manufacturing cost is 50,000 yuan, the tax rate is 15%, 0.5 yuan is calculated for every 0.001% vanadium, the weighted average price of process fuel is 2,000 yuan / t, the specific heat capacity of molten iron is 1130.44 kJ / (kg·℃), the electricity price is 0.57 yuan per degree, the thermal efficiency of the electric furnace is 40%, the weighted average carbon content of process fuel is 80%, and the weighted average price of process fuel is 2,000 yuan / t. The temperature value of molten iron per ton of iron (i.e. 1 ton of molten iron) is calculated at 0.45 yuan / ℃, the carbon content value is 12.5 yuan per 1% carbon content, and the vanadium content value is 0.67 yuan per 0.001% vanadium content.

[0091] The target V of the molten steel is 0.04% (calculation of vanadium extraction benefit), the target S is 0.001% (calculation of desulfurization cost), the target P is 0.001% (calculation of dephosphorization cost), the target temperature is 1280°C, and the target carbon content is 2%. The impact of the embodiment is shown in Table 5.

[0092] Among them, the single impact value is calculated according to formula (4), formula (5), formula (6), formula (7) and formula (8), the D value is calculated according to formula (9), and the P value is calculated according to formula (10). The data involved in the calculation are Table 4 and the molten steel target value, which is to adjust the molten iron composition to the molten steel target value through electric furnace smelting.

[0093] Table 5 Single item impact value and economic score

[0094]

[0095]

[0096] As can be seen from Table 5, the economic score of the process is calculated by the molten iron composition and temperature to evaluate the economy of the process. The higher the score, the more economical the process is.

[0097] In summary, the present invention scores and rates the slag quality and process by the recovery rate of valuable elements, and calculates the economic score of the process by the composition and temperature of molten iron. The calculation is simple, and the evaluation index is simple and fast. It can clearly and objectively evaluate the molten slag after deep reduction of vanadium-titanium magnetite metallized pellets in an electric furnace, the quality level of vanadium-containing molten iron, the technical level of the deep reduction process itself, and the economic level of the process. The user can make a comprehensive evaluation of the technical level and economy of the process, or evaluate a certain item separately, and can use it flexibly according to actual conditions. This evaluation method comprehensively considers the influence of factors such as carbon, sulfur, phosphorus, vanadium and temperature in molten iron, and can evaluate the deep reduction molten vanadium-containing molten iron more comprehensively and objectively, and has good innovation and practicality.

[0098] The description of the above embodiments is only used to help understand the method of the present invention and its core idea. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features disclosed herein.

Claims

1. An evaluation method for the process of deep reduction smelting of vanadium-titanium magnetite metallized pellets in an electric furnace, comprising at least one of a technical score calculation and an economic score calculation; The technical score calculation includes: The calculation formula of vanadium recovery rate is shown in formula (1): Vanadium recovery rate = total mass of vanadium-containing molten iron × mass fraction of vanadium in molten iron / (total mass of vanadium-containing molten iron × mass fraction of vanadium in molten iron + total mass of molten slag × mass fraction of vanadium in molten slag) formula (1); The calculation formula of titanium recovery rate is shown in formula (2): Titanium recovery rate = total mass of molten slag × mass fraction of titanium in molten slag / (total mass of vanadium-containing molten iron × mass fraction of titanium in molten iron + total mass of molten slag × mass fraction of titanium in molten slag) formula (2); The calculation formula of iron recovery rate is shown in formula (3): Iron recovery rate = total mass of vanadium-containing molten iron × mass fraction of iron in molten iron / (total mass of vanadium-containing molten iron × mass fraction of iron in molten iron + total mass of molten slag × ferrous content in molten slag × mass fraction of iron in ferrous iron) Formula (3): Classification of vanadium-containing molten iron: 80% to 85% of vanadium recovery rate and 97% to 98% of iron recovery rate are qualified products; 80% to 85% of vanadium recovery rate and more than 98% of iron recovery rate, or more than 85% of vanadium recovery rate and more than 97% to 98% of iron recovery rate are good products; more than 85% of vanadium recovery rate and more than 98% of iron recovery rate are excellent products; Slag classification: The recovery rate of titanium element in slag is 88% to 90% for qualified products, the recovery rate of titanium element in slag is 90% to 92% (inclusive) for good products, and the recovery rate of titanium element in slag is greater than 92% for excellent products; When the slag and iron are classified as unqualified, qualified, first-class, and superior, the scoring rules are the same, which are recorded as -10, 30, 40, and 50 respectively. The sum of the scores of slag and iron quality evaluation is the process score. The process evaluation is: The economic efficiency score calculation includes: Calculate the influence of sulfur (S), phosphorus (P), vanadium (V), carbon (C) and molten iron temperature on the value of molten iron. The influence of sulfur (S) and phosphorus (P) on the value of molten iron is calculated based on the actual removal cost. The influence of carbon, vanadium and molten iron temperature on the value of molten iron is calculated according to the following formulas respectively; The calculation formula of the influence value of molten iron S is shown in formula (4): Molten iron S impact value = (molten iron S content - molten steel target S content) × desulfurization cost, yuan / t formula (4); The calculation formula of the influence value of molten iron P is shown in formula (5): Hot metal P impact value = (hot metal P content - molten steel target P content) × desulfurization cost, yuan / t (formula (5)); The calculation formula of the influence value of molten iron V is shown in formula (6): Molten iron V impact value = (molten iron V content - molten iron V content after vanadium extraction) ÷ 102 × 182 × vanadium recovery rate × (vanadium pentoxide market price - vanadium pentoxide production cost) ÷ tax rate, yuan / t formula (6); The calculation formula of the influence value of molten iron C is shown in formula (7): Molten iron C impact value = (molten iron C content - molten steel target C content) / weighted average carbon content of process fuel × weighted average price of process fuel, yuan / t formula (7); The calculation formula of the influence value of molten iron temperature is shown in formula (8): (molten iron temperature - molten steel temperature) × molten iron specific heat capacity × electricity price / (3600 × electric furnace thermal efficiency), yuan / t Formula (8); Scoring rules: Before calculation, select the reference molten iron composition and temperature, or use the specified blast furnace molten iron composition and temperature as the reference value; According to formula (4) to formula (8), the influence values ​​of the corresponding factors of the base molten iron and the molten iron are calculated respectively, and then the influence value of the molten iron is subtracted from the influence value of the base molten iron, and the absolute value is taken as the value of the molten iron compared with the base molten iron; Single economic score D = the value of the single factor of molten iron compared with the benchmark molten iron / max (the corresponding single factor's molten iron impact value, the benchmark molten iron impact value) × 100 (9); The total economic score P = (molten iron vanadium score + molten iron temperature score + molten iron sulfur score + molten iron score + molten iron carbon score) / 5 (10).

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