Method for reducing steelmaking production cost by adding iron-containing miscellaneous materials

Abstract

The invention relates to the technical field of steelmaking production, in particular to a method for reducing steelmaking production cost by adding iron-containing miscellaneous materials, which comprises the following steps: step 1, arranging a blanking device above a transported iron ladle, and placing the iron-containing miscellaneous materials in the blanking device; 2, materials arranged in the discharging device are iron-containing miscellaneous materials with the iron content being 40%-92%; step 3, adding iron-containing miscellaneous materials with corresponding mass according to the temperature of the molten iron in the iron ladle, wherein the iron-containing miscellaneous materials contain fly ash materials; according to the method, surplus heat in high-iron-consumption production can be effectively utilized, the purity of molten steel is controlled, the oxygen consumption and the iron consumption are reduced, and the problems existing in the background technology are solved.

Description

Technical Field

[0001] The invention relates to the technical field of steelmaking production, in particular to a method for reducing steelmaking production costs by adding iron-containing miscellaneous materials. Background Art

[0002] Iron-containing debris is a variety of solid waste containing a certain amount of iron produced by steel companies during sintering production, blast furnace ironmaking, converter steelmaking, and rolled steel production. Reusing these iron-containing debris can effectively improve resource utilization, reduce environmental pollution and production costs.

[0003] In the current high-iron consumption steelmaking, the temperature of the molten steel in the high-temperature molten iron converter is high, which makes it difficult to control the superheat of the molten steel during the continuous casting process, affecting the rhythm of steelmaking production, and even causing production accidents such as crystallizer leakage. The measure currently taken by a steel plant is to add stones whose main component is CaCO3 to the converter to regulate the temperature. This treatment method will increase the procurement cost of CaCO3 stones, and waste excess heat, resulting in increased production costs. For this reason, we propose a method to reduce the production cost of steelmaking by adding iron-containing miscellaneous materials in the iron ladle. Summary of the invention

[0004] The object of the present invention is to provide a method for reducing the steelmaking production cost by adding iron-containing impurities, so as to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] As an optional solution of the method for reducing steelmaking production cost by adding iron-containing impurities according to the present invention, a method for reducing steelmaking production cost by adding iron-containing impurities comprises the following steps:

[0007] Step 1: a feeding device is arranged above the transported iron ladle, and iron-containing miscellaneous materials are placed inside the feeding device;

[0008] Step 2: The material set inside the feeding device is iron-containing miscellaneous material with an iron content of 40%-92%;

[0009] Step 3: Add corresponding mass of iron-containing miscellaneous materials according to the temperature of the iron-laden molten iron, wherein the iron-containing miscellaneous materials contain dust removal ash materials.

[0010] As an optional scheme of the method of reducing steelmaking production cost by adding iron-containing impurities described in the present invention, the dust removal ash in step three is processed into a spherical shape.

[0011] As an optional scheme of the method of reducing steelmaking production cost by adding iron-containing impurities described in the present invention, the feeding device includes a feeding hopper and a feeding pipe, the bottom of the feeding hopper is connected to the feeding pipe, and the other end of the feeding pipe is located above the iron ladle.

[0012] As an optional scheme of the method for reducing steelmaking production cost by adding iron-containing impurities described in the present invention, the bottom of the feed pipe is 20 cm away from the upper end of the iron ladle.

[0013] As an optional solution of the method of reducing steelmaking production cost by adding iron-containing impurities described in the present invention, the feed pipe is arranged in a vertical Z shape.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The invention rationally utilizes the surplus heat generated in high iron consumption production by adding iron-containing impurities, avoids the heat waste caused by adding high-calcium stone to reduce the temperature of molten steel in the converter steelmaking process, stabilizes the temperature of molten steel and reduces the production cost;

[0016] Stable molten steel temperature can also ensure the smooth progress of the subsequent continuous casting process and improve the quality of continuous casting products;

[0017] The added iron-containing impurities can reduce the silicon content in the molten iron, reduce the oxygen consumption in the converter steelmaking process, reduce the iron consumption in steelmaking production, control the purity of the molten steel and further reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention is a schematic diagram of the structure of a feeding device for a method of reducing steelmaking production costs by adding iron-containing impurities.

[0019] In the figure: 1-discharge hopper, 2-discharge pipe, 3-iron ladle. DETAILED DESCRIPTION

[0020] Example 1: Please refer to Figure 1 , the present invention provides a technical solution:

[0021] A method for reducing steelmaking production costs by adding iron-containing impurities comprises the following steps:

[0022] Step 1: a feeding device is arranged above the transported iron ladle, and iron-containing miscellaneous materials are placed inside the feeding device;

[0023] Step 2: The material set inside the feeding device is iron-containing miscellaneous material with an iron content of 40%-92%;

[0024] Step 3: Add corresponding mass of iron-containing materials according to the temperature of the molten iron, wherein the iron-containing materials include dust removal ash materials.

[0025] The dust removed in step 3 is processed into a ball shape.

[0026] When the molten iron temperature reaches 1400℃, 7.95t of iron-containing impurities are added to the 120t iron ladle being transported through the unloading structure to replace the 4.5t of high-calcium stone added to the converter;

[0027] The iron-containing miscellaneous materials have a grade of 20%-92%, including 3.5t of dust, 450kg of cast iron blocks, 3t of iron oxide scale, and 1t of sintered ore. The dust should be processed into balls and added to the iron bag.

[0028] The grade of dust removal ash is 40%, the price is 50 yuan / ton; the grade of cast iron block is 92%, the price is 2920 yuan / ton; the grade of iron oxide scale is 70%, the price is 500 yuan / ton; the grade of sintered ore is 54%, the price is 850 yuan / ton; the price of high calcium stone is 111.8 yuan / ton,

[0029] The cost of molten steel is 2440 yuan / ton, and the cost of scrap steel is 2064 yuan / ton. The iron content of the above iron-containing materials and the cost of producing a ton of steel are:

[0030] Dust removal: 50 / 40% = 125 yuan / ton

[0031] Iron content 3.5×40%=1.4t

[0032] Cast iron block: 2920 / 92% = 3173.9 yuan / ton

[0033] Iron content 0.45×92%=0.414t

[0034] Iron oxide: 500 / 70% = 714.3 yuan / ton

[0035] Iron content 3×70%=2.1t

[0036] Sintered ore: 850 / 54% = 1574.1 yuan / ton

[0037] Iron content 1×54%=0.54t

[0038] Cost of high calcium stone: 111.8×4.5=503.1 tons / furnace

[0039] Iron loss reduction: 120 / 125-120 / 129.454=33kg / t

[0040] The above 7.95t of iron-containing miscellaneous materials contain 4.454t of iron elements in total, which can reduce iron consumption by about 30kg / t. Cast iron blocks are produced in the iron-making process and must be recycled. From the above calculation, it can be obtained that the iron-containing miscellaneous materials except cast iron blocks can greatly reduce the steelmaking production cost.

[0041] In addition, the Fe oxide in the iron-containing impurities reacts with the Si element in the iron ladle to improve the purity of the molten iron.

[0042] Taking iron oxide scale as an example, 3 tons of iron oxide scale with a grade of 70% is added. Since the composition of iron oxide scale is basically iron oxide, the oxygen content is:

[0043] 3×30%=0.9t

[0044] 2Fe2O3+3Si==4Fe+3SiO2 320 84 224 180

[0046] In the reaction equation, the atomic mass of oxygen is 96 and that of silicon is 84. Theoretically, 0.9t of oxygen can react with 0.7875t of silicon to improve the purity of molten iron. In actual production, since it is impossible for the iron-containing impurities added to the iron ladle to react completely, the silicon content in the molten iron can be reduced from 0.5% to about 0.3%.

[0047] The incompletely reacted oxygen element can continue to react with elements such as P, S, Si, and C during the converter steelmaking process, reducing the amount of oxygen blown into the converter and thus reducing production costs.

[0048] 2FeO+Si==SiO2+2Fe

[0049] 2FeO+Si+2CaO==Ca2SiO4+2Fe

[0050] FeO+C==CO+Fe

[0051] Fe2O3+3C==3CO+2Fe

[0052] 5FeO+4CaO+2[P]==4CaO·P2O5+5Fe

[0053] 5FeO+3CaO+2[P]==3CaO·P2O5+5Fe

[0054] [S]+(CaO)==(CaS)+[O]

[0055] Similarly, the oxygen content in the above iron-containing impurities is:

[0056] Dust ash (main components are 15% CaO, FeO):

[0057] 3.5×11.4%+3.5×15%×28.6%=0.55t

[0058] Iron oxide scale (mainly composed of Fe2O3, FeO, Fe3O4):

[0059] 3×30%=0.9t

[0060] Sintered ore (main components are Fe3O4, SiO2, 15% CaO):

[0061] 1×54%×38.1%+1×15%×28.6%=0.25t

[0062] 7.95t of iron-containing impurities contain 1.7t of oxygen elements, which react in the iron ladle and converter. In actual production, it replaces 550m 3 Oxygen, reducing unit oxygen consumption by about 4.2m 3 . Oxygen cost 0.42 yuan / m 3 , which can reduce the cost per ton of steel by 1.764 yuan.

[0063] The added iron-containing miscellaneous materials not only make full use of the surplus heat, but also save the funds for adding high-calcium stones, thus greatly reducing the production cost.

[0064] Example 2: This example is an improvement on Example 1. Figure 1 Specifically, the above-mentioned feeding device includes a feeding hopper 1 and a feeding pipe 2, the bottom of the feeding hopper 1 is connected to the feeding pipe 2, and the other end of the feeding pipe 2 is located above the iron ladle 3;

[0065] The bottom of the feed pipe 2 is 20 cm away from the upper end of the iron ladle 3 .

[0066] The feed pipe 2 is arranged in a vertical Z shape.

[0067] The feeding pipe 2 is arranged in a Z shape, which can slow down the falling speed of the material, thereby avoiding the splashing of molten iron and causing serious safety hazards. At the same time, the feeding pipe 2 is 20 cm away from the top of the iron ladle 3, which can reduce the falling distance of the iron-containing impurities, thereby reducing the falling speed and avoiding material splashing.

[0068] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A method for reducing steelmaking production costs by adding iron-containing impurities, characterized in that: The following steps are involved: Step 1: a feeding device is arranged above the transported iron ladle, and iron-containing miscellaneous materials are placed inside the feeding device; Step 2: The material set inside the feeding device is iron-containing miscellaneous material with an iron content of 40%-92%; Step 3: Add corresponding mass of iron-containing materials according to the temperature of the molten iron, wherein the iron-containing materials include dust removal ash materials.

2. A method for reducing steelmaking production costs by adding iron-containing impurities according to claim 1, characterized in that: The iron-containing miscellaneous materials in step three include dust removal ash, cast iron blocks, iron oxide scale and sintered ore, and the dust removal ash is processed into a spherical shape.

3. The feeding device for reducing steelmaking production cost by adding iron-containing impurities according to claim 1, characterized in that: The feeding device comprises a feeding hopper and a feeding pipe. The bottom of the feeding hopper is connected with the feeding pipe, and the other end of the feeding pipe is located above the iron ladle.

4. A feeding device for reducing steelmaking production cost by adding iron-containing impurities according to claim 3, characterized in that: The bottom of the feed pipe is 20 cm away from the upper end of the iron ladle.

5. A feeding device for reducing steelmaking production cost by adding iron-containing impurities according to claim 4, characterized in that: The feed pipe is arranged in a vertical Z shape.

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