KR100995391B1 - Composition of additive for iron manufacture - Google Patents

Abstract

The present invention relates to an additive composition for steelmaking, and more particularly, to an additive composition for steelmaking including boron-based hydrates, boron-based oxides, dispersants, and carbonates. The additive composition for steelmaking according to the present invention is used as an additive in the ore smelting process to promote ore meltability even if the basicity in the furnace is low and deoxidation of ore by coal, coke (carbon) and water (hydrogen gas), etc. Of course, up to a constant temperature (1100 ° C.) has the advantage of improving the reactivity of the CO ₂ and the strength after the reaction of coke and coal well. In addition, even when molten and smelting temperatures are required up to 1600 ℃, when used in the injection ore and fuel to lower the melting point to improve the efficiency of the furnace.

Metal smelting, coke additives, furnace efficiency

Description

Steel additive additive composition {COMPOSITION OF ADDITIVE FOR IRON MANUFACTURE}

The present invention relates to an additive composition for smelting, and more particularly to a metal smelting additive composition comprising boron-based hydrate, boron-based oxide, glycerin or ethanolamine, and carbonate, melting ore even if the basicity in the furnace is low Promote the performance and lower the melting point when used in ore and fuel to improve furnace efficiency.

All ores are mostly in oxide state. In particular, examples of iron ore include hematite, magnetite, galmonite, and iron ore, all of which are not in the state of iron but in the form of iron oxide, which is a compound of Fe and O. Therefore, most ores are used for steelmaking in the furnace. Going through. Iron ore as a raw material, coke as fuel, and limestone as a solvent are put into a smelting furnace at a constant rate, and the iron ore melts and is reduced to produce pig iron. Reduction means that iron makes compounds with oxygen, but oxygen is separated from iron by iron lime, which is a solvent to facilitate pyrolysis, and iron becomes pig iron. Pig iron made in this way is very unsuitable for steel materials because it has a very high carbon content in iron and a high proportion of the five major elements of iron such as P, S, Mn, and Si, and controlling the content of the element is called steelmaking. It removes phosphorus and sulfur and controls the amount of Si, Mn and carbon appropriately. After steelmaking, work is performed to remove carbon, oxygen, and impurities remaining in the steel ingots, and the finished materials are solidified to produce the steel ingots. In this process, it is necessary to control the melting point of the ore to facilitate pyrolysis.

Coking, coal, and hydrogen gas are required as deoxidation and fuel in processing processes such as molten metal material. In particular, the coke used in the furnace, such as blast furnaces require a certain strength, reactivity and porosity, it is required to improve the efficiency of the furnace by improving it.

After melting, high temperature and heat are required to remove impurities such as carbon phosphorus, sulfur, and silicon from metal ingots such as pig iron, copper, zinc, and aluminum, and when used in combination, the melting point of ore and metal is adjusted to improve the efficiency of the furnace. Do it.

The present invention is to improve the reactivity and strength of the coke according to the situation of the furnace, and to provide a smelting additive composition that can control the melting point of the ore, thereby providing an additive composition for smelting metal that can increase the efficiency of the furnace and other than coke The efficiency of the furnace can also be increased by adding it to fuel or the like.

It is still another object of the present invention to provide a method for using a metal smelting additive composition which is added to an smelting additive composition ore or fuel and injected into a blast furnace or directly injected into a furnace.

In order to achieve the above object, the present invention provides an additive composition for metal smelting comprising boron-based hydrate, boron-based oxide, dispersant and carbonate.

The boron-based hydrate is sodium tetraborate decahydrate (Na ₂ B ₄ O ₇ · 10H ₂ O), ulexite (NaCaB ₅ O ₉ · 8H ₂ O), tin chalconite (Na ₂ B ₄ O ₅ (OH ) ₄ · 3H ₂ O), cannite (Na ₂ B ₄ O ₇ · 4H ₂ O), iyoite (Ca ₂ B ₆ O ₁₁ · 13H ₂ O), Na ₂ B ₂ O ₄ (OH) 4.6 H _At least one compound selected from the group consisting of ₂ O, NaBO ₂ .H ₂ O, Ba ₂ B ₈ C1 ₃ .4H ₂ O, and susecsite (MnBO ₂ (OH)), wherein the boron oxide is diborontrioxide. ), Na ₂ B ₂ O ₄ (OH) ₄ .6H ₂ O, NaBO ₂ .H ₂ O, Ba ₂ B ₈ C1 ₃ .4H ₂ O and 1 sucecite (MnBO ₂ (OH)) More than species. The metal may be iron, aluminum, zinc, or copper.

In addition, the present invention provides a method of using a metal smelting additive composition used by adding 10 to 15 weight ratio of the metal smelting additive composition to the ore.

Hereinafter, the present invention will be described in more detail.

The additive composition for metal smelting of the present invention includes boron-based hydrates, boron-based oxides, water-soluble dispersants and carbonates.

The composition preferably comprises 100 parts by weight of boron hydrate, 1 to 55 parts by weight of boron oxide, 5 to 250 parts by weight of dispersant, and 0.1 to 55 parts by weight of carbonate. At this time, when the content of each composition is out of the above range, it is not preferable because there is a problem such that it is difficult to apply the solid state or the melting point can not be adjusted, so that the operating conditions of the furnace cannot be kept constant.

The metal to which the additive composition for smelting of the present invention can be applied includes all metals requiring a smelting process and is not particularly limited, but iron, aluminum, zinc, copper, or copper is preferable.

Particularly in the present invention, boron hydrate and boron oxide act to increase the strength and reactivity of coke as well as to increase the solubility and solubility, deacidification and impurity removal rate through melting point control. The same effect can be obtained by adding to coke and other fuels and inputs, or by direct injection into the furnace.

The boron-based hydrate is sodium tetraborate decahydrate (decahydrate borax, Sodium tetraborate decahydrate, Na ₂ B ₄ O ₇ · 10H ₂ O), ulexite (ulexite, NaCaB ₅ O ₉ · 8H ₂ O), tincalconite (tincalconite _{, Na 2 B 4 O 5 (} OH) 4 · 3H 2 O), increased night _{(kernite, Na 2 B 4 O} 7 · 4H 2 O), am a child agent _{(Ca 2 B 6 O 11 ·} 13H 2 O), And at least one compound selected from the group consisting of Na ₂ B ₂ O ₄ (OH) 4.6 H ₂ O, NaBO ₂ .H ₂ O, Ba ₂ B _{8 C} 13.4 H ₂ O, and sussexite (MsBO ₂ (OH)). They have a lot of oxygen as boron-based oxides so that when dissolved, they provide oxygen or weaken the binding force of the impurities of the oxides, especially SiO ₂ , to dissolve the ore quickly. However, they are hard until they melt so that the ore or coke does not easily melt, thereby maintaining strength, thereby maintaining the air permeability of the furnace, thereby actively reacting with the ore due to the gas. If it is out of the above range it may be ineffective or inhibit the reduction and oxidation reaction in the furnace.

The boron-based oxide may be at least one compound selected from the group consisting of diboron trioxide (B ₂ O ₃ ), B ₂ O ₄ , HB ₂ O ₄ , NaBO ₄ , H ₃ BO ₃ and NaB ₂ O ₄ . . Boron-based oxide may include 1 to 55 parts by weight based on 100 parts by weight of the boron-based hydrate. These boron oxides not only remove impurities of the ore, especially silicon oxides from the ore, but also promote the role of the solvent of the calcium carbonate used as the ore solvent. Too much can impede the operation of the coke due to reduced strength and melting of the ore before the reaction.

The present invention is to promote the penetration of solid fuels such as coke and iron ore / coal and fossil fuels and biomass, while increasing the dispersibility to water, alkali metal hydroxides, glycerin, diglycerin, polyglycerine, monoethanolamine, Diethanolamine, triethanolamine, or polyvinyl alcohol may be used.

Preferred examples of the water-soluble dispersant are glycerin, diglycerin, polyglycerin, or ethanolamine, the content of which can be used within the range in which the boron hydrate is dissolved in water, preferably with respect to 100 parts by weight of the boron hydrate. 5 to 250 parts by weight may be added. These are mainly those having an OH group to cause ionic reactions with boron-based oxides and boron-based hydrates to enhance dispersibility, the precipitate may occur due to the disturbance of dispersibility or ionic binding force outside the above range.

The carbonate may be at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, calcium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and calcium hydrogen carbonate. Carbonate maintains the strength of the coke or the like in the furnace within a certain range in the boron-based hydrate to maintain breathability and improve the efficiency of the furnace. After a certain temperature (approximately 800 ° C.), reactions such as melting of boron hydrate or boron oxide become active, which accelerates the reaction and shortens the chemical and physical reaction time. Outside this range, it is ineffective or can weaken the coke's strength. At this time, the appropriate content is adjusted according to the operating conditions of the furnace and boron-based hydrate and is about 0.1 to 55 parts by weight relative to 100 parts by weight of the boron-based hydrate.

The composition preferably comprises 0.1 to 100 parts by weight of a compound selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide and polyvinyl alcohol, based on 100 parts by weight of the boron-based hydrate. These are mainly those having alkali metals or OH groups, which not only widen the role of the water-soluble dispersant but also prevent the role and precipitation of solvents in all the materials of the composition. Of course, this may adversely affect the refractory of the walls of the furnace.

More preferably, the composition may further include one or more compounds selected from the group consisting of silicates, aluminum compounds, nitrates, and hydrogen peroxide.

The silicate was used to further increase the strength of the coke and to increase the bonding strength of the boron hydrate, and preferred examples thereof include sodium silicate, potassium silicate, iron silicate, or calcium silicate, and the preferred amount thereof is 100 parts by weight of boron-based hydrate. It can be used at 0.1 to 250 parts by weight. SiO ₂ of these silicates generally plays the role of solvent in the furnace, and is separated at about 800 ℃ or more. After being separated, the acidic oxide is combined with boron hydrate to inhibit the coke reaction to prevent the strength from being weakened. In small cases, the effect is insignificant, and in excessive cases, the reduction and oxidation reactions may be inhibited, thereby preventing the role of the furnace.

The aluminum compound is sodium aluminate, aluminum acetate, or potassium aluminate, and the preferred amount of the aluminum compound may be 0.1 to 200 parts by weight based on 100 parts by weight of boron hydrate. In the present invention, as a method for suppressing the damage of the furnace wall, the aluminum-based compound properly adjusts the composition ratio, and as a result, the alkaline substance is discharged to the ash after the reaction to reduce the adverse effect of the furnace wall and bring about some (about 18%) desulfurization effect. Outside the range, the effect may be negligible or may react with other compositions to precipitate.

The nitrate is aluminum nitrate, manganese nitrate, magnesium nitrate, copper nitrate, iron nitrate, or zinc nitrate. It can be used 1 to 150 parts by weight based on 100 parts by weight of boron-based hydrate. These are combined with nitric acid, which are mainly alkaline oxides, but they prevent the ore from melting and tangling during reaction in the furnace, and are soluble in water so that they are easy to apply and use. Impurities in ores and bullions help to remove sulfur, phosphorus and sodium and potassium. Outside this range, the effect may be minor or may interfere with the effect of other compositions.

The hydrogen peroxide was used to increase the porosity of coke and iron ore and solid fuel by generating hydrogen when pyrolysis in the furnace by mixing hydrogen peroxide, the preferred amount can be used in 1 to 40 parts by weight based on 100 parts by weight of boron-based hydrate . When used in excess, radicals are decomposed before being introduced into the furnace and precipitates are generated in the composition by neutralization.

In addition, the composition is poured into the stirrer 100 parts by weight of 100 parts by weight of the boron-based hydrate in advance and then dispersed while stirring to prepare a water dispersion form to 50 to 100 ℃ to dissolve and disperse more quickly It may raise the temperature.

Such a method for producing the additive composition for fuel of the present invention is not particularly limited and can be prepared by conventional mixing. These compositions can be made without being greatly restricted in the order of mixing as long as they are dissolved in water in the form of dispersion.

Each component is mixed and reacted in a constant ratio to make a coke, or mixed prior to injection into ore and coke and other inputs such as coal, but may be used to mix, but may be directly injected into the furnace.

According to the present invention, it is preferable to add water to 1,000 parts by weight (10 times to 15 times by weight) by weight based on 100 parts by weight of the additive composition in the form of the aqueous dispersion.

The additive composition for metal smelting according to the present invention is used as an additive in the smelting and smelting process of the ore to promote ore meltability even if the basicity in the furnace is low, ore by coal, coke (carbon) and water (hydrogen gas), etc. The deoxidation and the removal of impurities such as Si, as well as the advantage of improving the reactivity of the coke CO ₂ and the strength after the reaction within a certain temperature (about 200 to 1700 ℃) range. This effect can be achieved even if mixed in the coke manufacturing process. In addition, even when molten and smelting temperatures are required to be higher than 1600 ℃, when used by injecting ore and fuel to improve the efficiency of the furnace by lowering the melting point. It also has desulfurization and denitrification effects.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the following examples are only examples of the present invention, and the present invention is not limited to these examples, and those skilled in the art can claim It will be understood that various modifications and changes can be made in the present invention without departing from the spirit and scope of the invention as set forth in the following.

Example  1: Composition Preparation

The metal smelting composition to be used in the present invention was prepared in the composition of Table 1 below. The sample compositions 1 to 4 were prepared.

TABLE 1

ingredient
division Sample 1 Sample 2 Sample 2 Sample 4 NaCaB ₅ O ₉ .8H ₂ 0 100 100 100 100 B ₂ O ₃ 21 21 21 21 glycerin 100 100 100 100 K ₂ CO ₃ 0 5 5 5 KOH 10 10 10 10 SiO ₂ 0 0 15 15 H ₂ O ₂ 0 0 0 20 NaAl ₃ 0 0 0 5 water 300 300 300 300

NaOH in the composition is 25% concentration liquid, hydrogen peroxide is 35% liquid and the rest are all solid compounds. The composition was dispersed by stirring 300 parts by weight of water based on 100 parts by weight of boron-based hydrate in a stirrer and adding glycerin and KOH while adding the composition according to the composition ratio of tinchalconat.

The following examples examine the enhancement of the strength and the degree of reactivity and porosity by controlling the melting point, and the improvement of furnace efficiency and the change of exhaust gas due to the melting point lowering and deoxidation, decarburization and dephosphorization, and desulfurization. It is to. Here, the reactivity by melting and deoxidation of the composition is controlled, and the strength after the reaction is also controlled by the difference between the reactivity and the complementary strength.

Example  2: experiment with

The purpose of this experiment is to combine the deoxidation, melting, lowering, coke reactivity, and strength improvement when the composition is actually used in the furnace. We want to know if environmental factors (NOx, S0x), exhaust gas, etc. are improved.

For sample compositions 1 to 4 of Table 1, 10 times of water was added for sample compositions 1 to 3 in the case of furnace experiments, and 15 times liter of water was added and diluted for Sample composition 4 and used. The most representative furnaces of the furnace were selected and carried out, and the size and operation method of the furnace are shown in Table 2 below.

The coke to be used in the present invention is as shown in Table 3 below. The components of the ore used in the experiment were 55.5 wt% Fe, 11.64 wt% Fe2, 4.85 wt% SiO ₂ , 1.15 wt% Al ₂ O ₃ , 11.35 wt% CaO, 1.66 wt% Mg, and 0.74 wt% Sg. It has iron ore.

TABLE 2

Furnace scale Driving method Daily iron production capacity 700 tons Air injection method A forced fan Seonbi (TON / m ³ ) 3.56 Cooling method Water-cooled Load rate (%) 80 Dust collection method Electrostatic precipitating Charging cycle 4 hours Air pressure (Kpa) 220 Size of the furnace (m ³ ) 150 Air volume (M ³ / M) 10,000 Design 4.48 Air temperature (℃) 1,150

[Table 3]

ingredient Content (unit: w / w%) moisture 8.6 Ash 2.3 Volatility 1.15 carbon 86.55 sulfur 0.62 Etc Trace ingredient

The results obtained in the above experiments are shown in Tables 4 and 5. In the table below, the amount of acid (daily iron production to furnace), sheath ratio (coke relative to 1 tonne of acid), granules (coke powder per tonne of acid), coal (coal per tonne of acid), load (coated iron tonnes per tonne of coke) and light ratio ( The amount of ore per tonne of acid) is expressed in Kg.

TABLE 4 Composition-free Group of the Present Invention

TABLE 5 Composition Addition Group of the Present Invention

As shown in Table 5, as a result of experiments for the sample compositions 1 to 4, the acid amount (daily iron production in the furnace) increased by 5.7%, 8.4%, 8.4%, 8.6%, respectively, and the ratio (coke consumption rate per tonne ore) Decreased by 4.3%, 8.9%, 6.5%, 6.5%, and 10.8%, and increased by 4.97%, 4.14%, 5.52%, and 8.01% of load (coated iron per tonne of coke), and carbon ratio (coal requirements per tonne of ore) 7.3%, 4.0%, 11.3%, and 13.7% decrease.

As a method for suppressing the damage of the furnace wall, the silicon and aluminum compounds are properly adjusted in composition ratio, and the alkaline substance is discharged into the ASH after the reaction, thereby reducing the adverse effect of the furnace wall. As shown in Table 1, the exhaust gas temperature was reduced by about 80 ° C during the experiment as shown in Table 6, and thus the furnace temperature was estimated to be about 100 ° C. Such low-temperature phenomenon is a low-temperature combustion progressed due to the enhancement of the reduction reaction, it is determined that not only the heat loss of the furnace but also the damage of the furnace wall. As shown in Table 5, NOx decreased by about 13% and 21%, respectively, and SOx decreased by about 11% and 18%, respectively.

Unlike Samples 1 to 3, in Sample 4, when 1,500 liters of water was added and tested, there was no decrease in the efficiency of the furnace due to water, thereby predicting a positive effect.

Example  3: Analysis of reaction characteristics by additive

The present embodiment investigates the improvement of the strength and the change of the exhaust gas due to the improvement of the strength by the control of the melting point, the degree of reactivity, the degree of porosity, etc., and the lowering of the melting point and deoxidation, decarburization and dephosphorization, and desulfurization. It is to. Here, the reactivity by melting point and deoxidation of the composition is controlled, and the post-reaction strength is also controlled by the difference between the reactivity and the complementary strength.

3-1: Reactivity and Strength Test

For sample compositions 1 to 4 of Table 1, the furnace operation conditions, coke and iron ore were substantially the same as in Example 2, and experiments were conducted to examine the reactivity and strength effects after the addition of the composition.

Reactive Coke Reactivity Index (CRI) and Coke Strength After Reaction (CSR) were tested four times, and were performed according to the Test Method Chinese Coke Standard Guide GB / T400-1996. This is to make a pilot furnace with conditions similar to those of the furnace, and then put the coke in the furnace and heat the electricity from about 200 ° C to 1100 ° C, passing CO ₂ gas through the furnace, and compare the change in the mass of the coke before and after the addition of the composition by reduction. The index is calculated according to the schedule calculation method.

TABLE 6

Item No additives adding Sample 1 Sample 2 Sample 3 Sample 4 shame Contents value value Difference
(%) value Difference
(%) value Difference
(%) value Difference
(%) 3-1 CRI 27.2 23.5 -13.6 30.9 13.6 28.9 6.25 30.2 11 CSR 69.2 73.6 6.4 72.6 4.9 76.5 10.5 76.2 10.1 3-2 Melting point
(℃) 1,550 1,380 -11 1,210 -21.9 1,612 4 1,630 5.16 3-3 Dispersibility
(mg) 100 110 1.1 253 153 311 211 3-4 Porosity
(%) 48 46 -4 55 20

As a result of the strength test, the value of 2.9 was increased when 15 parts by weight of silicate was added, and the value of 3.6 was added when 5 parts by weight of the aluminum compound was added.

3-2: melting point reduction experiment

For sample compositions 1 to 4 of Table 1, furnace operating conditions, coke and iron ore were substantially the same as in Example 2, and the melting point lowering experiment was performed.

Coke reactivity and strength were controlled and the ore melting point was controlled. Table 1 Performed in accordance with the International Measuring Method Standard ASTM -P1857 in combination with the composition, the ore to which a constant (about 200 g) was added was collected, put into a temperature measuring instrument, and slowly warmed up to start melting for the first time (IDT). The experimental results are shown in Table 6, and can be adjusted to about 350 ° C.

3-3: Dispersibility Experiment

For sample compositions 1 to 3 of Table 1, furnace operating conditions, coke and iron ore were substantially the same as in Example 2, and the dispersibility assay was performed after the addition of the composition. Table 1 Combination with the composition according to the International Measuring Method Standard ASTM-P1857, ore with a composition (about 200 g) added to the temperature measuring instrument and slowly warmed up to start melting (IDT) test results Obtained with Example 3, it was possible to adjust to about 350 degrees.

Dispersibility was compared by measuring the amount of melting in grams in 500 ml of beaker containing 25 ℃, 100ml of water and wet with a stick chopsticks. As a standard, the amount of the boron-based hydrate and the boron-based oxide was compared based on 100 without adding a dispersant. The results are shown in Table 6 above.

3-4: Porosity

For sample compositions 3 to 4 of Table 1, the porosity (%) was determined by measuring the weight before and after the addition of the composition by the Chinese Cokes Standard Guide Method GB4511.1-84 (Cokes-determination of show porosity) to determine the degree of improvement in porosity. Table 6 shows. As a result, the additive composition had a 48% porosity with respect to the no additive group, and obtained 46% with silicon oxide and 55% with hydrogen peroxide and 20% improvement.

Claims (9)

As an additive composition for steelmaking containing boron-based hydrate, boron-based oxide, dispersant, and carbonate, The boron-based hydrate is sodium tetraborate decahydrate (Na ₂ B ₄ O ₇ · 10H ₂ O), ulexite (NaCaB ₅ O ₉ · 8H ₂ O), tin chalconeite (Na ₂ B ₄ O ₅ (OH) ₄ .3H ₂ O), cannite (Na ₂ B ₄ O ₇ .4H ₂ O), iyoite (Ca ₂ B ₆ O ₁₁ .13H ₂ O), Na ₂ B ₂ O ₄ (OH) _At least one compound selected from the group consisting of ₄ .6H ₂ O, NaBO ₂ .H ₂ O, Ba ₂ B ₈ C1 ₃ .4H ₂ O), and susecsite (MnBO ₂ (OH)), The boron-based oxide is at least one compound selected from the group consisting of diboron trioxide (B ₂ O ₃ ), B ₂ O ₄ , HB ₂ O ₄ , NaBO ₄ , H ₃ BO ₃ and NaB ₂ O ₄ , iron Additive composition for use. The composition of claim 1, wherein the composition comprises a) 1 to 55 parts by weight of boron oxide, c) 5 to 250 parts by weight of dispersant, and d) 0.1 to 55 parts by weight of carbonate based on 100 parts by weight of boron-based hydrate. Steel additive composition. The steel additive composition according to claim 1, wherein the carbonate is at least one compound selected from the group consisting of potassium carbonate, sodium carbonate, calcium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and calcium hydrogen carbonate. The steelmaking agent according to claim 1, wherein the dispersant is at least one compound selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, glycerin, monoethanolamine, diethanolamine, triethanolamine, and polyvinyl alcohol (PVA). Additive composition for use. The additive composition for steelmaking according to claim 1, wherein the composition further comprises at least one compound selected from the group consisting of silicates, aluminum compounds, nitrates, and hydrogen peroxide. The method of claim 5, wherein the silicate is sodium silicate, potassium silicate, iron silicate, or calcium silicate, the aluminum compound is sodium aluminate, aluminum acetate or potassium aluminate (potassium aluminate) ), And the nitrate is aluminum nitrate, manganese nitrate, magnesium nitrate, copper nitrate, iron nitrate, or zinc nitrate. Phosphorus steel additive composition. delete The additive composition of claim 1, wherein the composition further comprises 100 to 2,000 parts by weight of water based on 100 parts by weight of the boron-based hydrate. 10 to 1,500 parts by weight of water is mixed with respect to 100 parts by weight of the additive composition for steelmaking according to any one of claims 1 to 6 and 8, and mixed with coke in the process of producing coke, or ore and coke in the furnace How to use the additive composition for steelmaking is to be mixed before use.