JP2014205893A - Manufacturing method of flaky ferronickel and manufacturing facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of flaky ferronickel capable of having a percentage of the flaky ferronickel having a maximum diameter of less than 20 mm of 90% or more in a ferronickel manufacturing.SOLUTION: A melting ferronickel is poured to a disc 11 having a diameter of 300 to 500 mm formed by a silicon carbide refractory containing alumina of 45 to 100% and alumina refractory or silicon carbide of 30 to 90%, the disc 11 is rotated at 150 to 300 rpm, and the melting ferronickel dispersed by the disc 11 is dropped into water and cooled.

Description

  The present invention relates to a method for producing flaky ferronickel in ferronickel smelting, and a production facility therefor.

  Ferronickel is an alloy mainly composed of iron and nickel, and is used as a raw material for stainless steel and special steel. As a general manufacturing method, dry smelting using nickel oxide ore (hereinafter also simply referred to as “ore”) as a raw material and comprising a drying step, a firing and partial reduction step, a reduction melting step, a desulfurization step, and a casting step. Is used.

  Specifically, first, in the drying step, after ore is blended so as to have a predetermined blending quality, a part of the water is removed.

  In the next calcination and partial reduction process, after adding a reducing agent such as coal to the ore and a melting agent as necessary, and putting it in the rotary kiln, the remaining moisture in the ore is completely removed, Reduced ore (hereinafter also referred to as “calcined ore”) is obtained.

  Next, in the reduction melting step, the obtained burned ore is reduced and melted in a reduction furnace such as an electric furnace or a blast furnace to obtain crude ferronickel and slag. The crude ferronickel produced from the reduction furnace is controlled to a nickel quality of 15 to 25% by weight by adjusting the amount of reducing agent added. This crude ferronickel is mainly composed of nickel and iron, and contains cobalt, sulfur and the like as impurities. Slag is mainly composed of iron oxide, silicon dioxide, and magnesium oxide, and is used as a melting agent, a fine aggregate for alphalt, a fine aggregate for concrete, and the like in the steel industry.

  Depending on the product specifications, the crude ferronickel obtained in the reduction-melting process can be subjected to a mechanical stirring type desulfurization process using a ladle or a desulfurization process using an electromagnetic induction stirring type purification furnace. Moved. In the desulfurization step, a desulfurizing agent such as calcium carbide is added to the crude ferronickel so as to obtain a desired sulfur content, and the sulfur in the crude ferronickel is fixed in the desulfurized slag as calcium sulfide (CaS). To remove.

  In the final casting step (step of obtaining flaky ferronickel), molten ferronickel obtained in the desulfurization step, or molten ferronickel that does not require desulfurization treatment according to product specifications, is converted into an ingot or flaky ferronickel (ferrous ferronickel). Nickel shot). The ingot is obtained by casting molten ferronickel. On the other hand, flaky ferronickel is poured into a disk provided at a position higher than the surface of the water in the center of the water tank, and then the disk is rotated to scatter and flake and fall into the water tank. Obtained by cooling.

  In recent years, flaky ferronickel having a small size has been required because it can be easily melted and is easy to handle, and a technique for reducing the size of the flaky ferronickel is required. Specifically, there is a demand for a technique capable of producing a ratio of flaky ferronickel having a maximum diameter of less than 20 mm at a ratio of 90% or more. However, since ferronickel is a refractory metal and has high viscosity, it has been very difficult to reduce the size of the flaky ferronickel.

  As a method for controlling the particle size of a flaky metal, for example, Patent Document 1 discloses a technique for adjusting zinc, which is a low melting point metal, to a desired particle size by adjusting the rotational speed of a disk. However, as described above, ferronickel is a high-melting-point metal and has a high viscosity, so that its property is greatly different from that of zinc which is the subject of the technique described in Patent Document 1. Therefore, in producing flake-like ferronickel, the technique cannot be applied as it is.

Japanese Unexamined Patent Publication No. 63-103007

  Therefore, the present invention has been proposed in view of such circumstances, and in producing flaky ferronickel in ferronickel smelting, the ratio of flaky ferronickel having a maximum diameter of less than 20 mm is 90% or more. It aims at providing the manufacturing method of the flaky ferronickel which can be performed, and its manufacturing equipment.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have obtained a disk having a predetermined diameter by a refractory made of a material having high strength at high temperature and suitable wettability with molten ferronickel. And flaky ferronickel having a maximum diameter of less than 20 mm can be effectively produced by rotating the disk at a predetermined rotational speed.

  That is, the method for producing flaky ferronickel according to the present invention is a method for producing flaky ferronickel in the production of ferronickel, which is an alumina refractory or silicon carbide containing 45 to 100% of molten ferronickel. Is poured into a 300 to 500 mm diameter disk formed of silicon carbide refractory containing 30 to 90%, and the disk is rotated at 150 to 300 rpm to drop the molten ferronickel scattered by the disk into water. And cooling.

  Here, in the manufacturing method of the above-mentioned flaky ferronickel, it is preferable that the temperature of the molten ferronickel poured into a disk is 1300-1500 degreeC.

  The molten ferronickel is preferably poured into the disk at a rate of 0.6 to 1.0 t / min per unit time.

  The flaky ferronickel manufacturing facility according to the present invention is a manufacturing facility for manufacturing flaky ferronickel in ferronickel manufacturing, and 30 to 90% of an alumina refractory or silicon carbide containing 45 to 100% of alumina. % Of a silicon carbide refractory containing 300% in diameter, a driving device for rotating the disk at 150 to 300 rpm, and a water tank for containing water. Nickel is poured, and the molten ferronickel scattered by the rotation of the disk falls into the water contained in the water tank and is cooled.

  According to the present invention, flaky ferronickel having a maximum diameter of less than 20 mm can be produced effectively, and the yield can be 90% or more.

It is a schematic diagram for demonstrating a state that the molten ferronickel poured into the disk is scattered in the form of flakes by the rotation of the disk. It is the block diagram which showed schematically the manufacturing equipment of flaky ferronickel.

  Hereinafter, specific embodiments of the method for producing flaky ferronickel according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, A change is possible in the range which does not deviate from the summary of this invention.

  The method for producing flaky ferronickel according to the present embodiment uses a nickel oxide ore as a raw material in ferronickel smelting, and includes a drying step, a firing and partial reduction step, a reduction melting step, and, if necessary, a desulfurization step. In this method, molten ferronickel obtained through the treatment is cast and formed into flaky (shot) ferronickel.

<Outline of casting process>
First, an outline of a method for casting molten ferronickel into flaky ferronickel will be described.

As described above, molten (crude) ferronickel is obtained through a reduction melting step in ferronickel smelting. As the typical composition, for example, when ore such as garnierite ore is used as a raw material, Ni grade is 15.0 to 25.0 wt%, S grade is 0.3 to 0.6 wt%, C grade Is 1.5 to 2.5% by weight, and the SiO ₂ quality is 0.5 to 2.0% by weight. Moreover, the temperature of this molten ferronickel is about 1300-1600 degreeC.

  In ferronickel smelting, after obtaining molten ferronickel having the above composition in the reduction melting process, desulfurization treatment is performed in the desulfurization process as necessary based on the product specifications, and the molten ferronickel is converted into flakes. It moves to the process (casting process) which obtains ferronickel.

  In the casting process, first, molten ferronickel is charged into a pan (a ladle). The melted ferronickel obtained from the reduction melting process or the like has a temperature of 1300 to 1600 ° C. to 1300 to 1500 ° C. before being put into the ladle.

  In this casting process, the molten ferronickel charged in the ladle is poured into a bowl or the like by tilting the ladle, and flows down to the approximate center (center) of the rotating disk via this bowl. We pour like we go. When the molten ferronickel flows down to the rotating disk via a rivet or the like, the molten ferronickel is allowed to flow vertically down the rotating disk so that the melt is formed into a cylindrical shape. The positional relationship (height difference) between this bowl and the rotating disk can be determined as appropriate according to the number of revolutions, the amount of pouring, etc. If the height difference is too large, the force applied to the disk due to the fall of molten ferronickel Increasing the possibility of troubles such as the disk becoming larger and missing during operation. On the other hand, if the height difference is too small, when the molten ferronickel falls on the rotating disk, it jumps upward, and the molten ferronickel that has bounced up adheres to the ridge and reduces the actual yield of ferronickel. From these things, it is preferable that the height difference between the ridge and the disk (the height of the ridge relative to the disk) is about 300 to 1000 mm.

  When molten ferronickel is poured into the substantially central portion of the disk in this way, the molten ferronickel spreads to the circumferential end of the disk, and as shown in the schematic diagram of FIG. The poured molten ferronickel is dispersed (scattered) in the form of flakes from the circumferential end of the disk. The scattered flaky molten ferronickel falls into the cooling pit, and is cooled and solidified by the water accommodated in the cooling pit to become flaky ferronickel.

  The obtained flaky ferronickel is transported from the cooling pit by a transporting conveyor or the like, dried by an intermediate drying device, and stored in a weighing hopper or the like. The flaky ferronickel stored in the weighing hopper is appropriately weighed, and a predetermined amount is stored in the container.

<Production conditions for flaky ferronickel>
Here, since ferronickel is a refractory metal and is a highly viscous metal, in the above-described casting process for obtaining flaky ferronickel, the size (diameter) of the flaky ferronickel is a desired size. It was difficult to control (range). Particularly in recent years, flaky ferronickel having a small size has been required from the viewpoint of easy handling, and a technique for obtaining it efficiently and in a high yield has been desired.

  As a result of studying the conditions for casting flaky ferronickel, the inventor of the present invention has a predetermined size using a refractory made of a material having high strength at high temperature and suitable wettability with molten ferronickel. It was found that a flaky ferronickel having a maximum diameter of less than 20 mm can be efficiently produced in a high yield by forming a (diameter) disk and rotating the disk at a predetermined rotational speed.

  Therefore, in the present embodiment, in the casting process described above, the molten ferronickel is formed of an alumina refractory containing 45 to 100% alumina or a silicon carbide refractory containing 30 to 90% silicon carbide. Pour into a disk with a diameter of 300-500 mm. Then, by rotating the disk at 150 to 300 rpm, molten ferronickel is scattered by the rotation of the disk, dropped into water, and cooled.

  According to this method, the ratio of the flaky ferronickel having a maximum diameter of less than 20 mm in the produced flaky ferronickel can be 90% or more, and the size is small in an efficient and high yield. Flaky ferronickel can be obtained.

(Disk material)
As described above, the disk is formed of an alumina refractory containing 45 to 100% alumina or a silicon carbide refractory containing 30 to 90% silicon carbide.

  After the molten ferronickel is poured into the approximate center of the disk and then spreads to the circumferential edge of the disk, a rotating force is transmitted from the rotating disk in the same direction as the disk, and the ferronickel rotates. It is scattered outside the disk by the centrifugal force generated by the force.

  Here, when the molten ferronickel is transmitted with a rotating force from the disk, it is necessary to make the surface roughness of the disk uniform so that the transmitted force is always constant. That is, when the surface roughness of the disk varies depending on the position, the force transmitted to the molten ferronickel also varies. If the force transmitted to the molten ferronickel varies depending on the position, the centrifugal force generated in the molten ferronickel also varies, so that the dispersion of the size of the scattered molten ferronickel increases. Therefore, in order to prevent a difference in surface roughness due to chipping of the surface during operation, the disk needs to have high strength at high temperatures. In the present embodiment, the disk is formed of an alumina refractory containing 45 to 100% alumina or a silicon carbide refractory containing 30 to 90% silicon carbide. Accordingly, even when high-temperature molten ferronickel is poured, chipping or roughening of the surface can be prevented, and a constant force can always be transmitted to the molten ferronickel.

  Further, when transmitting the rotating force to the molten ferronickel and scattering the molten ferronickel by the centrifugal force generated from the rotating force to obtain flaky ferronickel, the disc is made of an alumina refractory containing 45 to 100% alumina or By forming the silicon carbide refractory containing 30 to 90% of silicon carbide, wettability suitable for molten ferronickel can be generated. That is, wettability suitable for obtaining flaky ferronickel having a diameter of less than 20 mm can be produced. Thereby, molten ferronickel can be effectively scattered in the form of flakes having a diameter of less than 20 mm.

  Regarding the content ratio of the main component in each refractory, the alumina refractory contains alumina in a proportion of 45 to 100%. If the alumina content is less than 45%, the strength of the refractory is lowered. Also, in the case of a refractory with an alumina content of less than 45%, the wettability between the refractory and the molten ferronickel is improved (because the contact angle is reduced), so that the force attached to the refractory is increased and scattered. This is not preferable because the diameter of the obtained flaky ferronickel becomes large.

  Moreover, silicon carbide refractories contain silicon carbide in a proportion of 30 to 90%. In the case of a refractory with a silicon carbide content of less than 30%, the wettability between the refractory and the molten ferronickel is improved (because the contact angle is reduced), so that the force attached to the refractory increases and scatters. The diameter of the flaky ferronickel obtained is increased. Further, if the silicon carbide content exceeds 90%, not only the strength of the refractory is lowered, but also the silicon carbide content becomes very expensive as the silicon carbide content increases, so that it is efficient from the economical viewpoint. It is not preferable because it becomes impossible to perform the operation.

(Disc size)
The disk is formed by molding the above-described refractory so as to have a diameter of 300 to 500 mm. The thickness of the disk is not particularly limited, but can be about 100 mm, for example.

  As described above, the molten ferronickel is scattered by the centrifugal force generated by the rotating force transmitted from the rotating disk, but the peripheral speed at the end (circumferential end) of the disk decreases as the size of the disk decreases. Therefore, the rotating force transmitted to the molten ferronickel decreases and the centrifugal force also decreases. When this centrifugal force is reduced, the force at which the molten ferronickel is scattered from the disk is also reduced, and the size of the flaky ferronickel formed after the scattering is increased. Therefore, in order to reduce the size of the flaky ferronickel, the size of the disk needs to be a predetermined size or more. In the present embodiment, the disk has a diameter of 300 mm or more. Thereby, the ratio of the flaky ferronickel whose maximum diameter is less than 20 mm can be 90% or more.

  On the other hand, when the diameter of the disk exceeds 500 mm, the handling property is deteriorated. That is, since the disk rotates at a high speed, industrial handling becomes difficult, for example, high accuracy is required for mounting the rotating shaft at the center of the disk made of refractory.

(Rotation speed of the disk)
In addition, the rotation speed of the disk described above is 150 to 300 rpm.

  When the rotational speed of the disk is lowered, the rotational force that the molten ferronickel receives from the disk decreases, and the centrifugal force generated from this rotational force decreases. Then, the size of the molten ferronickel that is scattered by the centrifugal force increases. Therefore, in order to reduce the size of the flaky ferronickel, it is necessary to set the number of rotations of the disk to a predetermined value or more. In the present embodiment, the rotational speed of the disk is set to 150 rpm or more. Thereby, the ratio of the flaky ferronickel which can be manufactured using the disk mentioned above and whose maximum diameter is less than 20 mm can be 90% or more.

  On the other hand, when the rotational speed of the disk exceeds 300 rpm, industrial handling becomes difficult, for example, high accuracy is required for attaching a rotating shaft at the center of a disk made of refractory.

(Temperature of molten ferronickel)
Although it does not specifically limit as temperature of the molten ferronickel poured into the disk mentioned above, It is preferable that it is 1300-1500 degreeC.

  When the temperature of the molten ferronickel is less than 1300 ° C., in the casting process of obtaining this flaky ferronickel, for example, in the process of pouring molten ferronickel from a ladle into a disk via a rod, etc. Troubles such as the solidification of the molten ferronickel may occur, and the operation efficiency is lowered. On the other hand, when the temperature exceeds 1500 ° C., there is no particular problem with obtaining flaky ferronickel, but all the sensible heat to the molten ferronickel in the previous reduction melting step is lost, so the temperature is high. Min, the loss of heat energy increases.

  The method for adjusting the temperature of the molten ferronickel is not particularly limited. For example, when the temperature is low, a lance is inserted into the molten ferronickel placed in the ladle and oxygen is blown into the molten ferronickel. The temperature of nickel can be raised.

(Amount of molten ferronickel poured)
The amount of molten ferronickel poured into the disc per unit time (hereinafter referred to as “the amount of pouring”) is not particularly limited, but is preferably 0.6 to 1.0 t / min.

  When the pouring amount is less than 0.6 t / min, the production amount per unit time is lowered, so that the production efficiency is lowered. On the other hand, when the pouring amount exceeds 1.0 t / min, the rate at which the ladle is tilted becomes faster when pouring into a bowl or the like connected to a rotating disk from the ladle. When the speed at which the ladle is tilted is high, the amount of pouring becomes large, and it becomes difficult to keep the pouring amount constant. Moreover, when the amount of pouring is temporarily increased due to the variation in the amount of pouring, the level of molten ferronickel flowing through the soot increases, and there is a possibility that the molten ferronickel adheres to the upper end of the soot. When such adhesion to the soot is repeated, the adhesion amount of the molten ferronickel increases, resulting in a decrease in the actual yield.

<Flake ferronickel production equipment>
Next, manufacturing equipment used in the method for manufacturing flaky ferronickel according to the present embodiment will be described.

  FIG. 2 is a configuration diagram schematically showing a flaky ferronickel production facility 10. As shown in FIG. 2, this manufacturing equipment 10 includes a disk 11 into which molten ferronickel is poured, a drive device 12 that rotates the disk 11 at a predetermined rotational speed, and a molten ferronickel that is scattered by the rotation of the disk 11. And a water tank 13 serving as a cooling pit for cooling and solidifying.

  As described above, the disk 11 is made of an alumina refractory containing 45 to 100% alumina or a silicon carbide refractory containing 30 to 90% of silicon carbide, and has a diameter of 300 to 500 mm. Yes. The disk 11 is installed inside a water tank 13 to be described later, and is exposed above the surface of the water stored in the water tank 13 at the tip of a support shaft (rotary shaft) 11a that supports the disk 11. Is provided.

  In the disk 11, molten ferronickel charged in the ladle 14 is poured into a substantially central portion of the disk 11 via a not shown iron or the like. The surface of the disk 11 is a smooth surface, and the molten ferronickel poured into the disk 11 spreads uniformly at the circumferential end without variation. In addition, when pouring molten ferronickel from the ladle 14 to the disk 11 via a bowl or the like, the ladle is adjusted so that the amount of pouring per unit time is about 0.6 to 1.0 t / min. It is preferable to pour hot water while gradually inclining 14.

  The drive device 12 drives the disk 11 described above to rotate at a predetermined rotational speed. Specifically, in the manufacturing facility 10, the drive device 12 drives the rotating shaft 11a that supports and rotates the disk 11, thereby rotating the disk 11 at a rotational speed of 150 to 300 rpm. Due to the rotation of the disk 11 by the drive of the driving device 12, the molten ferronickel poured on the disk 11 scatters in the form of flakes from the circumferential end.

  The water tank 13 is a cooling pit containing water therein. As described above, the water tank 13 is provided with the disk 11 so as to be exposed above the water surface. The molten ferronickel scattered from the disk 11 is dropped into the water, and the molten ferronickel is cooled and solidified. Let Since the scattered molten ferronickel has a flaky shape, it is solidified as flaky ferronickel in the water in the water tank 13. In addition, the temperature of the water accommodated in the water tank 13 will not be specifically limited if it is the temperature which can solidify the molten ferronickel which fell in flakes, for example, can be about 50 degrees C or less.

  As described above, in the manufacturing facility 10 according to the present embodiment, the molten ferronickel charged into the ladle 14 is poured into the substantially central portion of the disk 11 and at the same time via the rotating shaft 11a by the drive device 12. The disk 11 rotates at a predetermined speed. Thereby, the molten ferronickel spread uniformly on the surface of the disk 11 scatters radially from the circumferential end. At this time, the scattered molten ferronickel has a flaky shape, and the flaky molten ferronickel falls into the water accommodated in the water tank 13. In particular, in the present embodiment, as described above, the disk 11 having a diameter of 300 to 500 mm made of an alumina refractory containing 45 to 100% alumina or a silicon carbide refractory containing 30 to 90% silicon carbide is used. By using and rotating the disk 11 at a rotational speed of 150 to 300 rpm, it is possible to effectively disperse the disk 11 into a flake shape having a maximum diameter of less than 20 mm.

  When the flaky molten ferronickel is cooled and solidified in the water in the water tank 13 to form flaky ferronickel as described above, the flaky ferronickel is transported by conveyors 15a and 15b provided in the manufacturing facility 10. Is conveyed by. The transport conveyors 15a and 15b are made of, for example, a mesh conveyor (net conveyor), and extremely fine ferronickel is removed.

  Moreover, the drying apparatus 16 is provided in the middle of conveyance by the conveyance conveyors 15a and 15b. The drying device 16 is made of, for example, a drying burner, and performs a drying process on the flaky ferronickel transported by the transporting conveyors 15a and 15b to remove moisture attached to the flaky ferronickel. Although it does not specifically limit as drying temperature, For example, it can be about 200-300 degreeC.

  The flaky ferronickel from which moisture has been removed by the drying device 16 is loaded and stored in a weighing hopper 17 provided at the ends of the conveyors 15a and 15b. The stored flaky ferronickel is weighed in a predetermined amount via the damper 17a and stored in the container 18.

  As explained in detail above, in the method for producing flaky ferronickel according to the present embodiment, molten ferronickel is an alumina refractory containing 45 to 100% alumina or silicon carbide containing 30 to 90% silicon carbide. Pour into a 300-500 mm diameter disk made of quality refractory and rotate the disk at 150-300 rpm to drop the molten ferronickel scattered by the disk into water and cool.

  According to such a method, it is possible to effectively produce flaky ferronickel having a maximum diameter of less than 20 mm, and the ratio of the flaky ferronickel less than 20 mm, that is, all the flaky ferronickels produced. The ratio (yield) of flaky ferronickel having a maximum diameter of less than 20 mm among nickel can be 90% or more.

  In addition, since a disk formed of the above-described alumina refractory or silicon carbide refractory is used, not only flaky ferronickel having a maximum diameter of less than 20 mm can be effectively obtained, but also at the high temperature. Since the strength is high, the replacement frequency can be suppressed, and the operation efficiency including the operation cost can be remarkably improved.

  Examples of the present invention will be described below in comparison with comparative examples. In addition, this invention is not limited by these Examples.

[Example 1]
In ferronickel smelting, molten ferronickel was obtained by sequentially carrying out the respective processes in the drying step, firing and partial reduction step, reduction melting step, and desulfurization step on the nickel oxide ore.

  And the obtained molten ferronickel was poured on the rotating disk on the conditions shown below, and the flaky ferronickel was obtained.

(1) Disc material: High alumina refractory (alumina content 60%)
(2) Disk size: Diameter 300mm, thickness 100mm
(3) Disk rotation speed: 170 rpm
(4) Melt ferronickel temperature: 1300 ° C
(5) Pouring amount (pouring speed): 0.8 t / min
(6) Shape of ridge: width 0.6m, inclination angle 11 °
(7) Amount of water stored in cooling water pit: 170t
(8) Cooling water pit water temperature: 50 ° C or less

  The ratio of the flaky ferronickel obtained under the above conditions was 99.8% with a maximum diameter of less than 20 mm, far exceeding the product standard of “90% or more”. Table 1 shows the results. The ratio of the flaky ferronickel having a maximum diameter of less than 20 mm ("the ratio of -20 mm flaky ferronickel" in Table 1) is obtained as the weight of the obtained flaky ferronickel having a maximum diameter of less than 20 mm. It was determined by dividing by the total weight of the flaky ferronickel (the “ratio by the diameter of the flaky ferronickel” in Table 1 was also determined by the weight ratio).

[Example 2]
In Example 2, when flaky ferronickel was obtained by pouring molten ferronickel into a rotating disk, a disk formed of an alumina refractory having an alumina content of 45% was used, and the rotation speed was 150 rpm. The same procedure as in Example 1 was performed except that the amount of molten ferronickel poured was 1.0 t / min.

  As shown in Table 1, the flaky ferronickel obtained under the above conditions had a maximum diameter of less than 20 mm, which was 99.5%, far exceeding the product standard of “90% or more”.

[Example 3]
In Example 3, when a molten ferronickel was poured into a rotating disk to obtain flaky ferronickel, a disk having a diameter of 500 mm formed of an alumina refractory having an alumina content of 100% was used, and the number of rotations was changed. The procedure was the same as in Example 1 except that the temperature was 300 rpm, the temperature of the molten ferronickel was 1500 ° C., and the amount of the molten ferronickel poured was 0.6 t / min.

  As shown in Table 1, the flaky ferronickel obtained under the above conditions had a maximum diameter of less than 20 mm, which was 99.9%, far exceeding the product standard of “90% or more”.

[Example 4]
In Example 4, when flaky ferronickel was obtained by pouring molten ferronickel into a rotating disk, a disk formed of a silicon carbide refractory having a silicon carbide content of 30% was used, and the rotation speed was 150 rpm. In the same manner as in Example 1, except that the amount of molten ferronickel poured was 1.0 t / min.

  As shown in Table 1, the flaky ferronickel obtained under the above conditions had a maximum diameter of less than 20 mm, which was 99.5%, far exceeding the product standard of “90% or more”.

[Example 5]
In Example 5, when flaky ferronickel was obtained by pouring molten ferronickel into a rotating disk, a disk having a diameter of 500 mm formed of a silicon carbide refractory having a silicon carbide content of 90% was used. The procedure was the same as in Example 1 except that the number was 300 rpm, the temperature of the molten ferronickel was 1500 ° C., and the amount of molten ferronickel poured was 0.6 t / min.

  As shown in Table 1, the flaky ferronickel obtained under the above conditions was 99.7% having a maximum diameter of less than 20 mm, far exceeding the product standard of “90% or more”.

[Example 6]
In Example 6, when the molten ferronickel was poured into a rotating disk to obtain flaky ferronickel, the same procedure as in Example 1 was performed, except that the temperature of the molten ferronickel was 1550 ° C.

  As shown in Table 1, the flaky ferronickel obtained under the above-mentioned conditions had a maximum diameter of less than 20 mm, which was 99.8%, far exceeding the product standard of “90% or more”. However, since the temperature of the molten ferronickel poured into the disk was as high as 1550 ° C., the loss of heat energy increased.

[Example 7]
In Example 7, when the molten ferronickel was poured into a rotating disk to obtain flake ferronickel, the same method as in Example 1 was used except that the amount of molten ferronickel poured was 0.5 t / min. went.

  As shown in Table 1, the flaky ferronickel obtained under the above conditions was 99.7% having a maximum diameter of less than 20 mm, far exceeding the product standard of “90% or more”. However, since the amount of molten ferronickel poured per unit time was slightly small at 0.5 t / min, the production amount per unit time was lowered.

[Comparative Example 1]
In Comparative Example 1, when the molten ferronickel was poured into a rotating disk to obtain flaky ferronickel, the same method as in Example 1 was performed except that the number of rotations of the disk was 85 rpm.

  In the operation in Comparative Example 1, as shown in Table 1, the flaky ferronickel obtained under the above-mentioned conditions has a maximum diameter of less than 20 mm, which is 73.4%, which is significantly lower than the product standard “90% or more”. It was.

[Comparative Example 2]
In Comparative Example 2, when the molten ferronickel was poured into a rotating disk to obtain flaky ferronickel, the same method as in Example 1 was performed except that the diameter of the disk was 150 mm.

  In the operation in Comparative Example 2, as shown in Table 1, the flaky ferronickel obtained under the above-mentioned conditions had a maximum diameter of less than 20 mm, which was 86.9%, which was lower than the product standard “90% or more”. .

[Comparative Example 3]
In Comparative Example 3, Example 1 was used except that when a flaky ferronickel was obtained by pouring molten ferronickel into a rotating disk, a disk formed of a clay refractory having an alumina content of 30% was used. The same method was used.

  In the operation in Comparative Example 3, as shown in Table 1, the flaky ferronickel obtained under the above-mentioned conditions had a maximum diameter of less than 20 mm, which was 88.1%, which was lower than the product standard “90% or more”. . This is because the wettability of the refractory and the molten ferronickel has improved, so that the force of the molten ferronickel adhering to the rotating disk has increased, and the centrifugal force generated in the molten ferronickel has been reduced. It is thought that the proportion of large flaky ferronickel increased. Also, in this operation, the disk was missing on the way, so the operation had to be stopped. This is thought to be due to the lack of strength at high temperatures of the disk due to the low alumina content of the clay refractory.

  DESCRIPTION OF SYMBOLS 10 Manufacturing equipment of flaky ferronickel, 11 disc, 11a Support shaft (rotary shaft), 12 Drive device, 13 Water tank, 14 Ladle, 15a, 15b Conveyor, 16 Drying device, 17 Weighing hopper, 17a Damper, 18 Container

Claims (4)

A method for producing flaky ferronickel in ferronickel production,
The molten ferronickel is poured into a 300 to 500 mm diameter disc formed of an alumina refractory containing 45 to 100% alumina or a silicon carbide refractory containing 30 to 90% silicon carbide, and the disc is poured at 150 to 300 rpm. A method for producing flaky ferronickel, which comprises cooling the molten ferronickel scattered by the disk by dropping it into water.   The temperature of the said molten ferronickel is 1300-1500 degreeC, The manufacturing method of the flaky ferronickel of Claim 1 characterized by the above-mentioned.   The method for producing flaky ferronickel according to claim 1 or 2, wherein the molten ferronickel is poured into the disk at a rate of 0.6 to 1.0 t / min per unit time. A production facility for producing flaky ferronickel in ferronickel production,
A disc having a diameter of 300 to 500 mm formed of an alumina refractory containing 45 to 100% alumina or a silicon carbide refractory containing 30 to 90% silicon carbide;
A driving device for rotating the disk at 150 to 300 rpm;
A water tank for containing water,
Flaked ferronickel is poured into a substantially central portion of the disk, and the molten ferronickel scattered by the rotation of the disk falls into the water contained in the water tank and is cooled. Manufacturing equipment.

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