TW201940707A - Stabilized aluminum slag composition for slag modifier and method of forming slag modifier - Google Patents

Abstract

The present invention provides a stabilized aluminum slag composition for a slag modifier. In some embodiments, the stabilized aluminum slag composition includes an aluminum slag, an aluminum scrap and a solid stabilizer. The solid stabilizer includes an inorganic acid, an organic acid, an organic acid salt or a combination thereof. Each of the organic acid and the organic acid salt has 2 to 18 carbon atoms. The solid stabilizer does not include sulfur, phosphor, and halogen. The present invention further provides a method of producing the slag modifier. The method includes performing a molding step on the stabilized aluminum slag composition, thereby forming the slag modifier.

Description

Stabilized aluminum slag composition for steelmaking slag modifier And manufacturing method of steelmaking slag modifier

The present invention relates to a stabilized aluminum slag composition and a method for manufacturing a steelmaking slag modifier for a steelmaking slag modifier, and more particularly, to a stable aluminum slag composition containing a solid stabilizer and A method for manufacturing a steelmaking slag modifier using high-pressure ingot pressing using the above-mentioned stabilized aluminum slag composition to obtain a steelmaking slag modifier having good properties.

Aluminum slag is often used as a modifier for steelmaking slag. In the reaction of high temperature furnace, aluminum and aluminum nitride in aluminum slag are effective reducing agents, which can reduce the content of iron, manganese and other oxides in steelmaking slag.

Further, hydrolysis of aluminum slag is highly exothermic reactions, in addition to the hydrolysis of aluminum nitride, aluminum carbide and other components such as aluminum Yi Jie release heat content contained in the following formulas (1) to (3): AlN _{(s )} + 3H ₂ O _(l) → Al (OH) _{3 (s)} + NH _{3 (g)} (1)

△ H = -53.2kcal / mol

Al _(s) + 3H ₂ O _(l) → Al (OH) _{3 (s)} + 3 / 2H _{2 (g)} (2)

△ H = -99.8kcal / mol

Al4C _{3 (s)} + 12H ₂ O _(l) → 4Al (OH) _{3 (s)} + 3CH _{4 (g)} (3)

△ H = -422.5kcal / mol

However, during the manufacture or storage of aluminum slag used as a modifier for steelmaking slag, aluminum nitride in the aluminum slag easily reacts to produce a foul odor (ammonia), which causes a serious environmental pollution problem. In order to improve the problem that aluminum nitride in aluminum slag is easy to react and produce malodor, nitrogen removal is one of the commonly used methods. The methods currently used include hot water removal, alkali removal, acid addition, alkali removal and temperature removal, Add alkali and pressurize to remove the temperature. The above-mentioned denitrification methods are all reacted under relatively severe conditions (acid, alkali and high temperature) to remove nitrogen from the aluminum slag, which is time-consuming and energy-consuming.

Therefore, if the aluminum slag can be properly treated, but the content of aluminum and aluminum nitride in the aluminum slag is not reduced, and the heat content in the aluminum slag is retained, and the odor is not generated, the aluminum slag can be applied more economically and efficiently. In steelmaking modifier.

A method is currently known which mixes flux materials such as fluorite and aluminum slag, and uses sodium hydroxide (or potassium) to react with aluminum metal in the aluminum slag to produce aluminum hydroxide as a binder. Then, the above-mentioned fluxing material and binder are pressed and dried to become a fluxing additive during smelting. However, the addition of alkali and water during the manufacturing process will cause the aluminum nitride in the aluminum slag to hydrolyze, generate an odor, and sacrifice the valuable aluminum metal in the aluminum slag.

Another method is to add 10% to 30% of asphalt to the fine powder of aluminum slag and make it into agglomerates. The purpose is to prevent the hydrolysis of aluminum nitride and the generation of dust during use when this agglomerate is used as a steelmaking flux. . However, adding too much bitumen to this method will produce a large amount of black smoke when the agglomerates are poured into molten steel, and even a severe splash phenomenon may occur.

Another method is to provide a new method for making granules and agglomerates. First, add a little water to the raw material of the steelmaking slag modifier to make it aggregate and agglomerate, and then coat the agglomerate with cement whose modifier is mixed and used in an amount of 5% to 20%. Thereafter, the agglomerated cement-coated agglomerates are cured and compression-molded. This method does not adopt the method of directly cementing the cement to granulate, so that the obtained steelmaking slag modifier can have a fast melting rate when it is put into molten steel, and promote the effective utilization of the slag. However, adding water during the manufacturing process will cause the aluminum nitride in the aluminum slag to hydrolyze and produce an odor.

Another method is to add a thermoplastic resin to the aluminum slag composition in the flux for steelmaking, and use the heat generated by frictional compression during granulation to soften the thermoplastic resin to use this resin as a binder. According to this, it is not necessary to add water, so as to have better shape retention, and it does not emit a lot of black smoke when used. However, the above method cannot effectively improve the disadvantage of odor generated by aluminum slag.

Another method is to use aluminum slag, calcium oxide, magnesium oxide, sodium carbonate, sodium bicarbonate, etc. as raw materials for the steelmaking slag modifier, and use high alumina cement and ordinary Poppertland cement to mix with the above raw materials. Among them, the ratio of high alumina cement to ordinary popper portland cement is 20:80 to 40:80, which is used as a binder and agglomerates, so that a steelmaking slag desulfurization and modification agent can be obtained. The added sodium bicarbonate and sodium carbonate can suppress the odor generated by ammonia during the manufacturing process. However, the use of cement as a binder for granulation results in excessively high strength of the modifier, slow melting when used, and the effect of sodium bicarbonate and sodium carbonate on inhibiting the hydrolysis of aluminum nitride to produce ammonia gas is not good.

Although the above methods respectively improve the application of aluminum slag for steelmaking slag modification Different shortcomings of the agent, but there are still problems such as fragility and pulverization during production and storage, odor generation, soot, splashing, and slow melting when put into steel drums. Therefore, the manufacturing method of the stabilized aluminum slag composition and the steelmaking slag modifier provided by the present invention proposes improved solutions to the above-mentioned disadvantages.

Therefore, an object of the present invention is to provide a stabilized aluminum slag composition which can be used for manufacturing a steelmaking slag modifier.

Another object of the present invention is to provide a method for manufacturing a steelmaking slag modifier, which uses the above-mentioned stabilized aluminum slag composition to obtain a steelmaking slag modifier.

According to the above aspect of the present invention, a stabilized aluminum slag composition is proposed. In some embodiments, the stabilizing aluminum slag composition comprises 30 weight percent (wt.%) To 95 wt.% Aluminum slag, greater than 0 wt.% To 65 wt.% Aluminum shavings, and 0.1 wt.% To 5 wt. % Solid stabilizer. The solid stabilizer comprises an inorganic acid, an organic acid, an organic acid salt, or a combination thereof. The carbon number of each of the organic acid and the organic acid salt is 2 to 18. The solid stabilizer is free of sulfur, phosphorus and halogen.

According to some embodiments of the present invention, the aluminum content of the aluminum slag is 5 wt.% To 50 wt.%.

According to some embodiments of the present invention, the aluminum content of the aluminum shavings is 75 wt.% To 95 wt.%.

According to some embodiments of the invention, the inorganic acid comprises boric acid.

According to some embodiments of the present invention, the organic acid includes oxalic acid, citric acid, tartaric acid, malic acid, salicylic acid, maleic acid, stearic acid, palmitic acid, lauric acid, or a combination thereof.

According to some embodiments of the present invention, the organic acid salt comprises stearates, palmitates, laurates, or a combination thereof.

According to some embodiments of the present invention, the aluminum slag, aluminum shavings, and solid stabilizer each have a particle size, and the particle size is not greater than 10 mesh.

According to the above aspect of the present invention, a method for manufacturing a steelmaking slag modifier is proposed. In some embodiments, the manufacturing method includes providing a stabilized aluminum slag composition as previously described. Then, a forming step is performed at a pressure of 2000 psi to 20000 psi to obtain the steelmaking slag modifier.

According to some embodiments of the present invention, the manufacturing method further includes pulverizing the aluminum slag, aluminum chips, and solid stabilizer in the stabilization composition, so that the particle size of the aluminum slag, aluminum chips, and solid stabilizer is not greater than 10 mesh.

According to some embodiments of the present invention, the stabilization composition does not contain water, and the manufacturing method excludes the step of adding water.

The invention provides a stable aluminum slag composition and a method for manufacturing a steelmaking slag modifier using the stable aluminum slag composition. The steelmaking slag modifier obtained by using the above specific composition and specific manufacturing method has high stability, is not easy to be crushed and powdered, and effectively reduces the odor generated by the decomposition of aluminum nitride in aluminum slag. Less soot is generated and the melting speed is fast.

100‧‧‧Stability test device

110‧‧‧closed cavity

120‧‧‧sample carrier

130‧‧‧ Absorbent

140‧‧‧ steelmaking slag modifier

In order to make the above and other objects, features, advantages of the present invention and The examples can be more clearly understood, and the detailed description of the attached drawings is as follows: [FIG. 1] is a schematic cross-sectional view showing the stability test device; and [FIG. 2] is an example 1 to 2 and comparative example 1 Histogram of ammonia release to 3.

The present invention aims to improve the shortcomings of the existing steelmaking slag modifier, such as: easy crushing and powdering during transportation, easy to produce odor, large amount of smoke and dust during use, even splash, and / or slow melting during use.

In view of the various disadvantages mentioned above, the present invention first proposes a stable aluminum slag composition, which has a specific composition and excludes specific substances, so as to avoid a reduction in the aluminum metal content in the stable aluminum slag composition. In addition, the present invention further provides a method for manufacturing a steelmaking slag modifier, which uses the above-mentioned composition in combination with specific process conditions to obtain a steelmaking slag modifier. The steelmaking slag modifying agent prepared by the method for producing a stable aluminum slag composition and a steelmaking slag modifying agent provided by the present invention may have many advantages, such as high stability, non-breakability and pulverization, and effective reduction. The odor produced by the decomposition of aluminum nitride in aluminum slag, the less smoke and dust generated when put into the steel drum, and the fast melting speed.

Stabilization aluminum slag composition

First, the stable aluminum slag composition of the present invention will be described below. In an embodiment, the stabilized aluminum slag composition may include 30 wt.% To 95 wt.% Aluminum slag, more than 0 wt.% To 65 wt.% Aluminum shavings, and 0.1 wt.% To 5 wt.% Solid stability. Agent.

Specifically, the solid stabilizer includes inorganic acid, organic Acid, organic acid salt, or a combination thereof. The carbon number of each of the organic acid and the organic acid salt is 2 to 18. In addition, the solid stabilizer is free of sulfur, phosphorus and halogen. If the solid stabilizer contains sulfur, phosphorus, and / or halogen, the odor of the steelmaking slag modifier cannot be effectively suppressed.

When the amount of the solid stabilizer used is too small, the odor of the steelmaking slag modifier that is prepared cannot be effectively suppressed. However, when the amount of the solid stabilizer used is excessive, the relative aluminum content in the steelmaking slag modifier is reduced, which affects the efficiency of the steelmaking slag modifier. In addition, if the solid stabilizer is dissolved in water to form an aqueous solution and mixed with aluminum slag and aluminum shavings, water will cause the aluminum content in the aluminum slag and aluminum shavings to hydrolyze and reduce, and will also affect the effectiveness of the steelmaking slag modifier. Therefore, in one embodiment, the stabilized aluminum slag composition of the present invention excludes the addition of water.

In some embodiments, the aluminum content of the aluminum slag is 5 wt.% To 50 wt.%. In other embodiments, the aluminum content of the aluminum scrap is 75 wt.% To 95 wt.%. In one example, the aluminum shavings may also be aluminum powder. The invention uses most of the aluminum slag with low aluminum content and few aluminum chips with high aluminum content to effectively treat the aluminum slag with low aluminum content, but saves the manufacturing cost, and can produce a steelmaking slag modifier with good use efficiency. For example, it can effectively reduce the content of iron and manganese oxides in steelmaking slag.

In some embodiments, the inorganic acid may include boric acid. In other embodiments, the organic acid comprises oxalic acid, citric acid, tartaric acid, malic acid, salicylic acid, maleic acid, stearic acid, palmitic acid, lauric acid, or a combination thereof. In still other embodiments, the organic acid comprises oxalic acid, citric acid, tartaric acid, malic acid, salicylic acid, maleic acid, stearic acid, palmitic acid, lauric acid, or a combination thereof. The solid stabilizers referred to herein in the present invention can be used alone or in combination with inorganic acids, organic acids or organic acid salts. Organic acids, organic acids and organic acid salts.

In some embodiments, each of the aluminum slag, aluminum shavings, and solid stabilizer has a particle size, and the particle size is not greater than 10 mesh. Specifically, the use of the above-mentioned aluminum slag, aluminum shavings, and solid stabilizer with a specific particle size facilitates the shaping of the steelmaking slag modifier, thereby improving the disadvantage of being easily broken and powdered during transportation and / or storage.

Manufacturing method of steelmaking slag modifier

The invention further provides a method for manufacturing a steelmaking slag modifier. In some embodiments, the manufacturing method includes providing the aforementioned stabilized aluminum slag composition, and the stabilized aluminum slag composition is uniformly mixed. Then, using a pressure of 2000 psi to 20000 psi, the forming step of the stabilized aluminum slag composition after uniform mixing is performed, so that a steelmaking slag modifier can be prepared.

In some embodiments, the forming step is a high-pressure ingot pressing step. If the pressure in the above-mentioned forming step is too small, the steelmaking slag modifier is too loose, and it is easy to be crushed and powdered during transportation or storage.

In some embodiments, the manufacturing method of the present invention further comprises a pulverizing step of the aluminum slag, aluminum shavings, and solid stabilizer in the stabilization composition, so that the particle size of the aluminum slag, aluminum shavings, and solid stabilizer is not greater than 10 Head.

In some embodiments, the stabilization composition does not contain water, and the manufacturing method of the present invention excludes the step of adding water.

Hereinafter, examples and comparative examples will be used to describe the production method of the stable aluminum slag composition and the steelmaking slag modifier of the present invention, and their effects.

Example 1

64.4 g of aluminum slag, 32.6 g of aluminum powder, 1 g of oxalic acid, and 2 g of stearic acid were mixed uniformly. A high-pressure ingot was pressed at a pressure of 7500 psi to prepare the steelmaking slag modifier of Example 1.

Example 2

64.4 g of aluminum slag, 32.6 g of aluminum powder, 2 g of oxalic acid, and 1 g of stearic acid were mixed uniformly. A high-pressure ingot was pressed at a pressure of 7500 psi to obtain the steelmaking slag modifier of Example 2.

Comparative Example 1

Comparative Example 1 uses a commercially available steelmaking slag modifier to perform the evaluation described later.

Comparative Example 2

Comparative Example 2 uses a commercially available steelmaking slag modifier to perform the evaluation described later.

Comparative Example 3

64.4 grams of aluminum slag and 32.6 grams of aluminum powder were mixed uniformly. A high-pressure ingot was pressed at a pressure of 7500 psi to obtain a steelmaking slag modifier of Comparative Example 3.

Evaluation method

Ammonia release from steelmaking slag modifier

The amount of ammonia released from the steelmaking slag modifier in the present invention is carried out by using the stability test device shown in FIG. 1. Specifically, the stability test apparatus 100 includes a closed cavity 110 and a sample carrier 120, wherein the sample carrier 120 is disposed in the closed cavity 110. 3wt.% Boric acid 100rnl was added to the closed cavity 110 as the absorption liquid 130, and the steelmaking slag modifier 140 of Examples 1 to 2 and Comparative Examples 1 to 3 were placed on the sample carrier 120, respectively. The stability test apparatus 100 was placed in an oven at 60 ° C. for 5 hours.

Next, the cooled absorption solution 130 was quantified to 200 ml, 5 ml of the quantitative absorption solution 130 was taken out, and 40 ml of reverse osmosis water and 2 ml of Nessler's reagent were added. After that, the above solution was quantified to 50.0 ml and left to stand for 20 minutes.

Then, the nitrogen content in the absorption liquid 130 was measured with a spectrophotometer to calculate the ammonia gas release amount of the steelmaking slag modifier of each of the examples and comparative examples. In general, the lower the ammonia release, the better.

The evaluation results of the ammonia gas release amounts of Examples 1 to 2 and Comparative Examples 1 to 3 are shown in FIG. 2.

As shown in FIG. 2, the ammonia gas release rate of the steelmaking slag modifier obtained by using the stable aluminum slag composition and the steelmaking slag modifier of the present invention is extremely low. However, if the solid stabilizer in the stabilized aluminum slag composition is not used, the ammonia gas release amount of the obtained steelmaking slag modifier is high (Comparative Example 3). In addition, the amount of ammonia released from various steelmaking slag modifiers (Comparative Examples 1 and 2) on the market is much higher than the present invention.

By applying the method for manufacturing a stabilized aluminum slag composition and a steelmaking slag modifier of the present invention, the prepared steelmaking slag modifier can have high stability, is not easily broken and powdered, and can effectively reduce nitriding in aluminum slag. The odor produced by the decomposition of aluminum, the less smoke and dust generated when it is put into the steel drum, and the fast melting speed.

Although the present invention has been disclosed as above with several embodiments, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field to which the present invention pertains can make various modifications without departing from the spirit and scope of the present invention. Changes and retouching, so the protection scope of the present invention shall be determined by the scope of the appended patent application.

Claims (10)

A stabilized aluminum slag composition comprising: 30% by weight (wt.%) To 95% by weight of aluminum slag; greater than 0% by weight to 65% by weight of aluminum chips; and 0.1% by weight to 5% by weight of solid stability Agent, wherein the solid stabilizer comprises an inorganic acid, an organic acid, an organic acid salt, or a combination thereof, each of the organic acid and the organic acid salt has a carbon number of 2 to 18, and the solid stabilizer is free of sulfur , Phosphorus and halogen. The stabilized aluminum slag composition according to item 1 of the scope of the patent application, wherein the aluminum content of the aluminum slag is 5 wt.% To 50 wt.%. The stabilized aluminum slag composition according to item 1 of the scope of the patent application, wherein the aluminum content of the aluminum shavings is 75 wt.% To 95 wt.%. The stabilized aluminum slag composition according to item 1 of the scope of patent application, wherein the inorganic acid comprises boric acid. The stabilizing aluminum slag composition according to item 1 of the scope of patent application, wherein the organic acid comprises oxalic acid, citric acid, tartaric acid, malic acid, salicylic acid, maleic acid, stearic acid, palmitic acid, lauric acid, or A combination of the above. The stabilized aluminum slag composition as described in item 1 of the patent application scope, wherein the organic acid salt comprises stearates, palmitates, laurels Acid salt or a combination thereof. The stabilized aluminum slag composition according to item 1 of the scope of the patent application, wherein the aluminum slag, the aluminum shavings, and the solid stabilizer each have a particle size, and the particle size is not greater than 10 mesh. A method for manufacturing a steelmaking slag modifier, comprising: providing a stable aluminum slag composition as described in any one of claims 1 to 7 of the scope of patent application; and performing a molding step at a pressure of 2000 psi to 20000 psi to The steelmaking slag modifier was prepared. According to the method for manufacturing a steelmaking slag modifier as described in item 8 of the scope of the patent application, the method further includes a pulverizing step of the aluminum slag, aluminum shavings, and solid stabilizer in the stabilization composition, so that the aluminum slag, A particle diameter of the aluminum shavings and the solid stabilizer is not greater than 10 mesh. The method for manufacturing a steelmaking slag modifier as described in item 8 of the scope of the patent application, wherein the stable composition does not contain water, and the manufacturing method excludes the step of adding water.