KR20040110181A - Method for manufacturing deoxidizer using aluminium dross through compression molding process - Google Patents

Abstract

PURPOSE: To provide a method for manufacturing a deoxidizer using aluminum dross, which is able to easily produce the deoxidizer from the aluminum dross through a compression molding process. CONSTITUTION: The method comprises the steps of (a) after crushing aluminum dross into particles, screening the particles having a size of not less than 0.50 millimeter and less than 10 millimeters; and (b) compression-molding the screened particles through a press under pressure of about 600 tons.

Description

Method for manufacturing deoxidizer using aluminum dross through compression molding process

The present invention relates to a method for producing a deoxidizer made of a metal component that is added to molten steel to be used for oxygen removal due to its strong affinity with oxygen. More specifically, the Al to Al alloy is extracted using aluminum dross and not cast. The present invention relates to a method for producing aluminum deoxidizer to be produced by compression molding.

Generally, the method of manufacturing steel removes impurities in the steel by blowing oxygen from the converter and the electric furnace, and inevitably removes oxygen remaining in the molten steel and slag by adding a deoxidizer and adjusting the proper composition and temperature. Casting is done.

At this time, the deoxidizer must be chemically reacted with oxygen in the molten steel within a predetermined time and then form a deoxidation product to rise above the ladle to be sufficiently separated from the molten steel. Therefore, the deoxidizer should have greater chemical affinity with oxygen than iron (Fe) in the normal molten steel temperature range, the reaction should be completed within a short time, and the flame or dust should not be excessively generated during the deoxidation reaction for the pleasant environment of the workplace. The extra components remaining after the reaction should not adversely affect the quality of the steel.

As elements having such properties, manganese (Mn), titanium (Ti), calcium (Ca), silicon (Si), aluminum (Al), etc. are widely used. Especially in the case of manufacturing sheet materials, oxygen and reaction equilibrium values are low. Aluminum is most commonly used, and in recent years, so-called complex deoxidizers such as alloys containing a small amount of other metals in aluminum, such as Si-Al-Fe, Si-Mn-Al-Fe, Ti-Al-Fe, for common deoxidation effects. Is also used.

Such aluminum deoxidizer is made by melting aluminum alloy scrap or aluminum ingot and casting it into a shape desired by the user.In the case of making aluminum deoxidizer by casting as described above, the short-term manufacturing time due to the dissolution and casting process increases and the price of the deoxidizer is too high. There is a problem of being expensive.

In addition, in the case of making an aluminum composite deoxidizer, it is prepared by adding and dissolving other metals to the dissolved aluminum as necessary, in which case there may be a component that cannot be added because the solubility difference is large or poorly soluble with aluminum. There is a problem that can not be prepared of various aluminum composite deoxidizer.

In addition, since aluminum is a metal that is well oxidized, aluminum dross is always generated whenever aluminum is dissolved. The aluminum dross is removed from the melting furnace when casting to the now after melting, and some remain in the melting furnace or crucible when the aluminum molten metal is poured into the mold, and is generated in a molten runner during the casting of the molten metal.

In Korea, in the conventional case, an aluminum melting company heats aluminum dross to melt it first or second, thereby reducing the amount of dross to be recovered and discarded aluminum metal in the dross. Or it is a common way to landfill by consignment. The final waste dross produced is mostly aluminum oxide, which is often mixed with 10-30% metallic aluminum, less than 10% salt, and impurities such as Mg, Si, Fe, etc. originally present in the Al scrap. .

When the aluminum dross is treated according to the conventional method, there is a problem in that the cost of securing landfill or waste aluminum dross processing cost is entrusted to the waste disposal company.

Accordingly, the technical problem to be solved by the present invention is to solve the problems described above, that is, a manufacturing process that can be used to reduce the aluminum dross, and to produce aluminum deoxidizer easily and inexpensively through a compression molding process rather than a casting process. To provide.

In order to achieve the above technical problem, the present invention

(a) subjecting the aluminum dross to a pulverization and screening process to screen the granules having a grain size of 0.50 mm or more and less than 10 mm; And

(b) compression-molding the selected granules at a pressure of about 600 tons through a press to provide a deoxidizer production method using aluminum dross.

In the deoxidizer manufacturing method according to the present invention as described above,

In the step (a), the pulverization and screen processes are preferably pulverized first through a ball mill, and then screened for particle size, and then refined through a metal sludge crushing apparatus through a second compaction roller to sort out those having a size of 0.50 mm or more and less than 10 mm. Do.

In addition, the deoxidizer manufacturing method according to the present invention is any one of the metal forming a complex deoxidizer with aluminum, such as Ca, Cu, Si, Fe, Zn, Mn, Mg, Ni, Ti, Sn, Pb, Cr, etc. before the step (a). It is preferred to carry out step (b) after the addition of one or more mixtures of 5-20% by weight.

Next, the manufacturing method of the deoxidizer using the aluminum dross which concerns on this invention is demonstrated in detail.

First, the aluminum dross used as a raw material in the present invention will be described.

Since aluminum is a well oxidized metal, aluminum dross is always generated whenever or when aluminum is dissolved. The aluminum dross is removed from the melting furnace when casting to the now after melting, and some remain in the melting furnace or crucible when the aluminum molten metal is poured into the mold, and is generated in a molten runner during the casting of the molten metal. Most of such aluminum dross is aluminum oxide, and there are many cases in which 10-30% of metallic aluminum, salts within 10%, and impurities such as Mg, Si, Fe, etc. originally present in Al scraps are mixed.

In the present invention, by re-dissolving in aluminum dross to recover the aluminum rather than using it as it is in the aluminum dross to remove inorganic materials such as aluminum oxide through the grinding, screening process to remove pure metal aluminum and other Mg, Si, Only granules containing metal components such as Fe or aluminum alloy are used for purification.

After first dissolving the dross generated during the dissolution of aluminum scrap or aluminum ingot, part of the aluminum in the dross was recovered, and the aluminum dross generated was quantitatively analyzed by element using ICP. Table 1 shows the results of the element analysis of small amounts of elements other than Al.

ingredient Mg Si Ti Mn Fe Sn Ni Ca K Na wt% 4.65 0.57 0.25 0.004 0.20 0.31 0.02 0.26 0.34 0.73

In the case of a small amount of elemental components other than aluminum shown in Table 1, all have stronger oxygen affinity than Fe and can be used as a deoxidizer, and since Fe is an original component of molten steel, it is not necessary to remove aluminum deodorant according to the present invention. It can be used as it is for a process.

However, there is a significant amount of inorganic materials that cannot be used as a deoxidizer, such as aluminum oxide contained in aluminum dross, but there is a need to remove them.

In order to remove ceramic inorganic materials that cannot be used as a deoxidizer, such as aluminum oxide, in the present invention, the metal aluminum component is mainly obtained by selecting only grains having a certain particle size through a process of crushing and screening aluminum dross. The process of obtaining the granule which remove | eliminated the inorganic substance which consists of other metal components or alloy components thereof as shown in 1, and which cannot be used as a deoxidizer is performed in this invention.

In other words, permanent deformation occurs without breaking the object against ductility and compression force, which is an object that is not destroyed by applying force exceeding the elastic limit, and is a property that can be made into thin pieces by applying pressure and strike to metal. When grinding through a mill with a ball mill or a compression roller using the properties of the metal, the metal is stretched or unfolded without breaking, resulting in grains having a certain size, but inorganic materials such as aluminum oxide are destroyed to form a powder. Because it is possible to select.

In the present invention, the grain size is 0.50 mm or more and less than 10 mm through the grinding and screening process using aluminum dross. A grain size of less than 0.50 mm is more difficult to be used as a deoxidizer due to the content of ceramic inorganic substances such as aluminum oxide than a metal component, and when the grain size exceeds 10 mm, the content of aluminum and other metal components is high and as a derailment agent. It can be used, but since the specific gravity is low when compression molding when used as a deoxidizer because it does not sink in the molten steel because there is a problem that the efficiency as a deoxidizer is lowered.

In the present invention, the pulverization, screening process can be performed using a general pulverizer without particular limitation, but preferably the first pulverized and screened through a ball mill and then crushed again through a metal sludge pulverizing apparatus through a squeeze roller to screen the grains It is preferable to select a size of 0.50 mm or more and less than 10 mm. Ball milling and screening using a metal sludge crusher through a compacting roller is the most efficient use of ductility and malleability that is characteristic of metals. Because you can get

In particular, the metal sludge crushing apparatus through the pressing roller used in the secondary crushing process is a patent No. 10-0338465 filed on September 21, 1999 and registered on May 16, 2002 by the present applicant "metal sludge crushing" Device "is preferred. The content of Patent No. 10-0338465 is included in the present specification, and the contents thereof are briefly described as follows.

Patent No. 10-0338465 describes a metal sludge crushing apparatus for crimping only aluminum while crushing metal, especially aluminum sludge, to supply and discharge grease and discharge air while the grinding and pressing idle rollers are safely leveled. By providing a metal sludge crushing device that can smoothly and prevent the intrusion of foreign substances in the device and arbitrarily control the supply amount of metal sludge,

A central rotary shaft (3) rotated at the center in the main body outer cylinder (1), a plurality of substrates (2) mounted in multiple stages rotated about the rotary shaft, and an idle shaft (4) provided on the outer circumferential surface of the substrate; In the metal sludge crushing apparatus consisting of a plurality of left and right idle grinding and pressing roller (5) connected to the idle shaft and idling about the central axis (7) of the roller,

Inverted U-shaped bracket 9 in which shaft holes 11 and 11 'are installed in upper and lower protrusions 24 and 24' on bracket housings 8 on the outer circumferential surface of the idle shaft 4 provided at the periphery of the substrate 2. Is fixed to the upper and lower bolts or rivets (10) (10 ') and the idle shaft 12 is laid in the vertical shaft holes (11) (11') and supported by the support (15, 15 ') above and below the idle shaft. One end of the upper and lower guide rods 13 and 13 'is fixed, and the other end 14a and 14a' of the upper and lower guide rods 13 and 13 'is a central shaft of a normal idle (rotating) roller 5. The upper and lower parts of the upper and lower parts of the upper and lower parts of the upper and lower parts of the upper and lower parts of the upper and lower parts of the upper and lower parts of the upper and lower parts of the upper and lower parts of the upper and lower parts (7) are fixed with the fixing pins 20 and 20 '. Retainer (18) (18 ') and V-ring (19) (19') are installed to prevent foreign matter from interfering with the bearing of the roller when crushing and compressing the metal sludge, and the upper roller bearing (21) The grease supply nipple (22) penetrates through the upper cover (17). The grease drain nipple 22 'is connected to the lower roller bearing 21' via the lower cover 17 'of the roller, thereby providing grease to the roller bearings 21 and 21' from time to time. It is possible to provide sufficient lubrication to the bearings, so that the roller rotation is good and the sludge supply amount adjusting screw 23 is installed under the metal sludge supply hopper 16 so that the sludge supply amount can be arbitrarily adjusted. Have.

Subsequently, by measuring the aluminum content of the granules of 0.50 mm or more and less than 10 mm after completion of the screening, the aluminum content was found to be sufficient to be used as a deoxidizer. It was judged. As a method for detecting the content of metal aluminum, any method may be used as long as the NaOH method (aka FOSECO method), HCl method, and the like are known in the art.

Next, when the screening is completed by compression molding the granules of 0.50mm or more, less than 10mm at a pressure of about 600 tons using a large press to complete the production of the deoxidizer according to the present invention.

In the present invention, because aluminum dross is used, other than aluminum included in aluminum dross, for example, metals such as Mg, Si, Ti, Mn, Fe, Sn, Ni, Ca, and the like are naturally contained in aluminum. Complex deoxidizers with the main component are possible, but Ca, Cu, Si, Fe, Zn, Mn, Mg, Ni, It is also possible to prepare a deoxidizer according to the present invention by mixing the aluminum, and any one or more mixtures of one or more of metals forming a complex deoxidizer such as Ti, Sn, Pb, Cr, and the like.

The amount of the other metal component to be mixed is preferably 5 to 20% based on the total weight of the deoxidizer, and the particle size of the metal included is similar to that of the grains selected in the previous process. It is easy to adjust the function and proper specific gravity.

In addition, in the present invention, the size of the grains selected using aluminum dross is 0.50 mm or more and less than 10 mm to prepare a deoxidizer, but considering the compression capacity and the specific gravity of the deoxidizer during compression, the most suitable size is It was found to be more than 0.50mm and less than 3.0mm.

Hereinafter, the present invention will be described in detail with reference to Examples. Apparently, the present invention is not limited by the examples described below.

<Example 1>

Deoxidizer manufacture

The aluminum dross sample used in this example was produced by a domestic aluminum recycling company, and is a waste aluminum dross produced after first recovering some aluminum in the dross by dissolving dross generated during scrap melting. .

The aluminum dross is first pulverized through a ball mill and screened to screen particles having a particle size of 0.5 mm or more and less than 10 mm, followed by regrinding and screening using a Harim mill described in Patent No. 10-0338465. Granules larger than mm and smaller than 3.0 mm were screened.

In order to measure the aluminum content of the selected grains, six samples were taken and the aluminum content was measured by NaOH method (aka FOSECO method). .

The selected granules were subjected to 25 kg / mm ² pressure using a press to prepare a deoxidizer having a diameter of 100 mm and a height of 85 mm.

The average weight of the deoxidizer thus prepared was 1,650 g, and the average specific gravity was about 2.473, indicating that it had sufficient specifications for use as a deoxidizer.

<Example 2>

Deoxidation Efficiency Test

Using the deoxidizer prepared in Example 1 was used in the production of a medium carbon-based carbon steel / alloy steel series such as SM45C, SCM440 and the efficiency was measured. In order to perform a comparison test, the conventional test was conducted in comparison with Forged Al, and the results are shown in Table 2.

division Input quantity during electric furnace tapping (kg / Heat, average) Delivery amount (kg) Molten steel component % Recovery EAF LHF Al Si-Mn Fe-Si Si Al Si Al Si Forged Al (A) 73 508 95 67,923 0.003 0.028 0.167 27.4 74.5 Invention (B) 70 512 89 66,409 0.005 0.025 0.166 26.9 74.5 Difference (A-B) -3 4 -7 -1,514 0.002 -0.003 0.001 -0.5 0.0

As shown in Table 2, it was found that the difference of the trace amount of about 0.5% in aluminum recovery rate showed that the efficiency of the deoxidizer according to the present invention was not inferior to that of the conventional deoxidizer.

However, the unit price of the deoxidizer according to the present invention is about 330 won per kg cheaper than the conventional Forged Al, and the expected savings based on the annual usage amount is about 230 million won.

Therefore, it can be seen that when using the deoxidizer according to the present invention at a low cost while showing a similar deoxidation efficiency can be seen a tremendous economic effect.

As described above, since the deoxidizer manufacturing method according to the present invention is manufactured by compression molding, it is possible to reduce about 10% of dissolution loss generated during dissolution and to reduce cost by reducing casting cost, and is not dissolved. Compression molding of the particles can significantly improve the yield of alloying components when adding poorly soluble alloying components or highly oxidizing elements.

In addition, the existing manufacturing process generates a large amount of pollution and waste when melting, but in the case of the present invention, the melting process is omitted, so that an environmentally friendly process can be implemented, and it is also very useful for resource recycling because it recycles waste aluminum dross. .

Claims (3)

(a) subjecting the aluminum dross to a pulverization and screening process to screen the granules having a grain size of 0.50 mm or more and less than 10 mm; And (b) compressing the selected granules at a pressure of about 600 tons through a press. The method of claim 1, The pulverization and screen process of step (a) is first pulverized through a ball mill, the particle size is screened, and then refined through a metal sludge crusher through a second compaction roller to screen the size of more than 0.50mm, less than 10mm Deoxidant production method using an aluminum dross. The method according to claim 1 or 2, Before the step (a), any one or a mixture of one or more of metals forming a complex deoxidizer with aluminum, such as Ca, Cu, Si, Fe, Zn, Mn, Mg, Ni, Ti, Sn, Pb, Cr, etc. Method for producing a deoxidizer using aluminum dross, characterized in that the step (b) after the addition of 5 to 20%.