JP3950390B2 - Method for producing anhydrous magnesium chloride and apparatus for extracting molten magnesium chloride - Google Patents

Description

【００３８】
本発明の方法で製造した実施例１の無水塩化マグネシウムは、比較例１に比べて、純度が高く、特にアンモニア成分が極めて少ないことが分かる。
【００３９】
実施例２
実施例１で得られた無水塩化マグネシウムを用いてオレフィン類重合用触媒を以下のように調製し、プロピレンの重合評価を行った。
（固体触媒成分の調製）
実施例１で得られた塊状の無水塩化マグネシウムを解砕し、その後振動ミルにて２時間粉砕した。このようにして得られた無水塩化マグネシウム３０ｇ、四塩化チタン２．３ｍｌ、およびフタル酸ジ−ｎ−ブチル３．０ｍｌを窒素ガスで十分置換した振動ミルに充填して１７時間共粉砕し、固体触媒成分を調製した。
（重合触媒の形成および重合）
窒素ガスで完全に置換された内容積２．０リットルの撹拌機付オートクレーブに、トリエチルアルミニウム１．３２mmol、シクロヘキシルメチルジメトキシシラン０．１３mmol、および前記固体触媒成分をチタン原子として０．００２６mmol装入し、重合用触媒を形成した。その後、水素ガス２．０リットル、液化プロピレン１．４リットルを装入し、２０℃で５分間予備重合を行った後に昇温し、７０℃で１時間重合反応を行った。このときの固体触媒成分１ｇ当たりの重合活性、生成重合体中の沸騰ｎ−ヘプタン不溶分の割合（ＨＩ）とメルトインデックスの値（ＭＦＲ）を表２に示した。
【００４０】
なお、ここで使用した固体触媒成分当たりの重合活性は下式により算出した。
重合活性＝生成重合体（ｇ）／固体触媒成分（ｇ）
また、生成重合体中の沸騰ｎ−ヘプタン不溶分の割合（ＨＩ）は、この生成重合体を沸騰ｎ−ヘプタンで６時間抽出したときのｎ−ヘプタンに不溶解の重合体の割合（重量％）とした。さらに、生成重合体のメルトインデックスの値（ＭＦＲ）は、ASTM D1238、又はJIS K7210に準じ、嵩比重（ＢＤ）はJIS K6721に準じて測定した。
【００４１】
比較例２
比較例１で製造した無水塩化マグネシウムを用いた以外は実施例２と同様に実験を行った。得られた結果を表２に示した。
【００４２】
【表２】

【００４３】
【発明の効果】
本発明の製造方法によれば、高純度、特にアンモニアの混入量が極めて少ない無水塩化マグネシウムを得ることができ、特にオレフィン類重合触媒担体に適した無水塩化マグネシムを得ることができる。また、本発明の溶融塩化マグネシウムの抜出し装置によれば、簡易な構造で設置場所も採らず、本発明の製造方法を確実に実施できる。
【図面の簡単な説明】
【図１】第１の実施の形態の溶融塩化マグネシウムの抜出し装置の概略図である。
【図２】第１の容器にある溶融塩化マグネシウムを冷却する方法を説明する図である。
【図３】固化後、解砕前の容器内密封状態を説明する図である。
【図４】第２の実施の形態の溶融塩化マグネシウムの抜出し装置の概略図である。
【図５】複数の容器の他の配列形態を示す図である。
【図６】複数の容器の他の配列形態を示す図である。
【符号の説明】
１Ａ、１Ｂ 溶融塩化マグネシウムの抜出し装置
２ 還元炉
３ 複数の容器
３ａ〜３ｅ 容器
４ 抜出し配管
６ａ〜６ｅ オーバーフロー配管
８ 外部容器
１０ａ〜１０ｃ 冷却用ガスの噴出ノズル
１１ 溶融塩化マグネシウム
１２ 金属チタンと塩化マグネシウム
１５ ロードセル内設の台座
１６ 固化無水塩化マグネシウム[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing anhydrous magnesium chloride, and more particularly, to a method for producing high-purity anhydrous magnesium chloride suitable for a carrier for olefin polymerization catalysts and an apparatus for extracting molten magnesium chloride used in the production.
[0002]
[Prior art]
Conventionally, magnesium chloride has been widely used as a raw material for the production of magnesium metal by electrolysis and as a raw material for catalysts, pharmaceuticals and chemicals. In particular, magnesium chloride used as a catalyst support material is required to be high-purity anhydrous magnesium chloride that contains no water of crystallization and has very few impurities.
[0003]
Anhydrous magnesium chloride has been produced by various methods for a long time. In Japanese Patent Application Laid-Open No. 55-20296, solid magnesium carbonate is reacted with chlorine at a temperature of 1200 ° C. or higher in the presence of carbon monoxide gas. A method for producing anhydrous magnesium chloride by removing anhydrous magnesium chloride is disclosed. In Japanese Patent Laid-Open No. 55-126534, a carnalite mineral is dissolved in a small amount of water, ethylene glycol is added to this, dehydrated, anhydrous ammonia is added to precipitate ammonium complex of magnesium chloride, and this is heated. Thus, a method for producing anhydrous magnesium chloride is disclosed.
[0004]
On the other hand, in the production of titanium metal by the crawl method, magnesium chloride is produced as a by-product in the process of producing titanium metal by reducing titanium tetrachloride with magnesium metal. Since this magnesium chloride is produced in a molten state, it becomes anhydrous magnesium chloride. Specifically, liquid titanium tetrachloride is dropped into a reduction furnace filled with molten metal magnesium to reduce titanium tetrachloride to produce sponge titanium. At this time, magnesium chloride is produced as a by-product. . This magnesium chloride is withdrawn into a molten magnesium chloride dedicated container in the molten state during the reduction reaction and after the reduction reaction. Most of this magnesium chloride is decomposed into metallic magnesium and chlorine by the electrolytic method for the production of metallic titanium and reused. In addition, when a part is transferred from the dedicated container to the electrolytic layer, it is separately extracted into a container such as a drum can, and then solidified and used for applications such as a catalyst and a pharmaceutical.
[0005]
Since anhydrous magnesium chloride obtained in the metal titanium production process by the crawl method is a by-product, the production cost is lower than the above-described production method using magnesium carbonate or carnalite as the raw material. Since there are few other metal components, it is used especially as a support | carrier raw material of a titanium type highly active olefin polymerization catalyst. Titanium-based highly active olefin polymerization catalysts include ethylene and propylene polymerization catalysts, and supported catalysts using a magnesium compound as a carrier material are the mainstream. In recent years, the performance of this olefin polymerization catalyst has been remarkably improved. In particular, its catalytic activity is very high, and several tens of kg of polymer per 1 g of catalyst can be obtained. Magnesium chloride is mainly used as a magnesium compound for a highly active olefin polymerization catalyst carrier, and the quality of magnesium chloride greatly affects the catalyst characteristics, particularly the catalyst activity.
[0006]
[Problems to be solved by the invention]
However, the molten magnesium chloride obtained as a by-product in the conventional titanium metal production process by the crawl method includes magnesium chloride extracted during the reduction reaction, so some unreacted molten metal magnesium in the reduction furnace is also somewhat It is mixed. When such high-temperature molten magnesium chloride is withdrawn from a reduction furnace into a container, such as a container such as a drum can, it comes into contact with moisture in the air and becomes a hydrate, which lowers the purity as an anhydride. Furthermore, when molten metal magnesium is mixed, it reacts with nitrogen gas in the air to become magnesium nitride, which reacts with moisture in the air to become magnesium hydroxide and ammonia, finally as impurities in the molten magnesium chloride. Mixed.
[0007]
In recent years, there has been a strong demand for higher activation of the catalyst in order to efficiently produce a polymer having high functionality such as a cost reduction requirement, a process improvement, and a copolymer in recent years. Improvement of the quality of magnesium chloride is desired. However, as described above, molten magnesium chloride transferred from a conventional dedicated container to a container such as a drum can contains a small amount of ammonia as an impurity, and when this is used as a carrier material for an olefin polymerization catalyst, the performance deteriorates. In particular, since it causes a decrease in catalyst activity, it does not necessarily satisfy the recent demand for further activation of the catalyst, and further improvement has been desired.
[0008]
Accordingly, an object of the present invention relates to a method for producing anhydrous magnesium chloride having a high purity and particularly an extremely small amount of ammonia, and particularly a method for producing anhydrous magnesium chloride suitable for an olefin polymerization catalyst carrier and a molten chloride used for the production. The object is to provide an apparatus for extracting magnesium.
[0009]
[Means for Solving the Problems]
As a result of intensive studies to solve the problems remaining in the prior art, the present inventors directly extract molten magnesium chloride generated in the titanium metal production process by the crawl method from the reduction furnace into the container. As a result, it was found that highly pure anhydrous magnesium chloride with a very small amount of ammonia mixed in was obtained, and the present invention was completed.
[0010]
That is, the present invention provides a reduction reaction between titanium tetrachloride and metallic magnesium in a reduction furnace. , Form metal titanium and magnesium chloride The reduction reaction is completed After that, the magnesium chloride in a molten state is directly extracted from the reduction furnace into a container and solidified in the container. Thus, a method for producing anhydrous magnesium chloride is provided.
[0011]
In addition, the present invention is a reduction furnace for reducing titanium tetrachloride and magnesium metal, and extracting magnesium magnesium in a molten state generated in the reduction furnace, The molten magnesium chloride Containment Then solidify A plurality of containers, and an extraction pipe disposed at the upper opening of the first container, one end of which is connected to the reduction furnace and the other end is in the uppermost stream. The container is placed at a position lower than the nearest upstream container, and is connected to each other by an overflow pipe, and a molten magnesium chloride extraction device is provided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
In the method for producing anhydrous magnesium chloride according to the present invention, in the production process of titanium metal by the so-called crawl method in which titanium tetrachloride is reduced with metal magnesium, first, molten metal magnesium is filled in a reduction furnace, and this is liquid titanium tetrachloride. Is dropped and a reduction reaction is performed in the range of 800 to 1000 ° C. In this reduction reaction, titanium tetrachloride is reduced, and powdered metal titanium is once generated, and then sintered to form sponge-like metal titanium in the reduction furnace. At the same time, the magnesium metal is salified to form molten magnesium chloride.
[0013]
In the present invention, the molten magnesium chloride withdrawn from the reducing furnace is not molten magnesium chloride withdrawn during the reduction reaction, but is molten magnesium chloride with a small amount of molten metal magnesium remaining after the completion of the reduction reaction. Usually, in the production process of titanium metal, magnesium chloride is a by-product, and when the production amount is increased during the reduction reaction, the titanium metal formation reaction is inhibited, so that it is withdrawn as needed during the reaction. And after dripping of titanium tetrachloride is complete | finished and a reductive reaction is complete | finished, the remaining molten magnesium chloride is extracted. However, the molten magnesium chloride extracted during the reduction reaction contains some unreacted molten metal magnesium in the reduction furnace. When such high-temperature molten magnesium chloride is extracted from the reduction furnace into a container, it comes into contact with moisture in the air to form a hydrate, and the purity as an anhydride is reduced. Further, when molten metal magnesium is mixed, it reacts with nitrogen gas in the air to become magnesium nitride, which reacts with moisture in the air to produce ammonia. On the other hand, in the method of the present invention, not the molten magnesium chloride extracted during the reduction reaction, but the molten magnesium chloride with a small residual amount of molten metal magnesium after completion of the reduction reaction is extracted. The amount of contamination can be reduced as much as possible. After completion of the reduction reaction of the present invention, the amount of molten metal magnesium in the molten magnesium chloride withdrawn is 0.1% by weight or less, and the amount of ammonia in the anhydrous magnesium chloride finally obtained is used for olefin polymerization. It is preferable in that it can be made less than 0.01% without adversely affecting the activity of the catalyst.
[0014]
In the present invention, the extraction of molten magnesium chloride directly into the container means that the molten magnesium chloride in the reduction furnace is transferred to the container through an extraction pipe without going through a separate container, for example. The tip of the extraction pipe is arranged in the insertion port formed in the lid or top plate of the container, that is, the form inserted in a loose fit state expels air in the container and suppresses contact with the atmosphere as much as possible. This is preferable in that smooth transfer can be performed. Thus, if the method of extracting molten magnesium chloride directly in a container is taken, the contact with air | atmosphere will be suppressed to the minimum and the production | generation of the ammonia compound of metallic magnesium can be suppressed.
[0015]
In the present invention, the container from which the molten magnesium chloride is withdrawn is not particularly limited, and examples thereof include a JIS 200 liter drum. Further, the container is preferably two or more interconnected containers, and in particular, the first container which is installed in such a way that the downstream container is positioned lower than the nearest upstream container, and is the most upstream container. It is preferable that the molten magnesium chloride withdrawn into the container is sequentially drawn out into the second and subsequent containers communicated by the overflow pipe. That is, when the number of containers to be extracted is two or more, in the method of arranging the extraction piping for each container and extracting it, the molten magnesium chloride comes into contact with the air each time and the quality deteriorates. Since the molten magnesium chloride remaining in the extraction pipe is solidified and clogged, the efficiency becomes very low. On the other hand, in the preferred container form of the present invention, since it is continuously extracted into a plurality of containers, contact with the atmosphere can be further prevented and high-purity anhydrous magnesium chloride can be obtained.
[0016]
In the method for producing anhydrous magnesium chloride according to the present invention, when the molten magnesium chloride is directly extracted from the reduction furnace into the vessel, it can be prevented from coming into contact with the atmosphere by performing it in an inert gas atmosphere. This is preferable in that high-purity anhydrous magnesium chloride can be obtained. Argon gas is preferably used as the inert gas. Specifically, it is preferable to draw out into a container under an inert gas atmosphere. At this time, it is preferable to use a container with a lid such as the drum can. By using a container with a lid, contact with the atmosphere can be avoided as much as possible, and higher purity solid magnesium chloride can be produced.
[0017]
As the argon gas, it is preferable to use degassed argon gas. Since commercially available argon gas contains very little moisture and other impurity gases, it is preferable to use a gas from which these gases have been removed in advance. Such degassed argon gas can be obtained, for example, by passing a commercially available argon gas in contact with a getter material such as a titanium material heated to about 400 to 500 ° C. Examples of the method of placing the container under an inert atmosphere include a method in which the entire plurality of containers are housed in a sealable external container. That is, the outer container has a structure in which the inside can be replaced with an inert gas such as argon gas and pressurized to a little higher than the atmosphere. Before extracting the molten magnesium chloride from the reduction furnace, accommodate a plurality of containers in the outer container, and replace the outer container and the container with argon gas or dry air to remove moisture as much as possible. It is good to keep.
[0018]
Next, the extracted molten magnesium chloride is solidified in the container to obtain solid anhydrous magnesium chloride. When molten metallic magnesium is mixed in the molten magnesium chloride, the molten magnesium chloride is directly contained in the container from the reduction furnace. It is desirable from the viewpoint that it is possible to remove the metal magnesium after solidification by allowing it to float on the upper part and then removing the metal magnesium after solidification because it is reliable and easy to remove. As a method of floating molten metal magnesium before solidification, there is a method of leaving it for a while without using a forced cooling means.
[0019]
As described above, the molten magnesium chloride extracted from the reduction furnace into the container is preferably cooled and solidified as quickly as possible in terms of shortening the contact time between the molten magnesium chloride and the atmosphere. This can be achieved by using a relatively small container, such as a 200 liter drum, for extracting molten magnesium chloride. In addition, it is also preferable to adopt a mode in which argon gas is injected into the entire molten magnesium chloride container, or a cooling device configuration by so-called forced convection in which argon gas is blown evenly around the container.
[0020]
The solidified magnesium chloride is crushed and then pulverized. In particular, when used as an olefin polymerization catalyst carrier, it is desirable to grind until the average particle size is 100 μm or less. Crushing means that massive anhydrous magnesium chloride is mechanically made into granules or flakes of 1 mm to 10 cm using a hammer mill or a crusher, and pulverization means the granules or flakes. It means that it is powdered by a ball mill or a vibration mill. In addition, when pulverizing, the particle size of magnesium chloride is refined, and the crystal structure of magnesium chloride is broken to make it amorphous. Can be improved. After pulverization, anhydrous magnesium chloride with fewer impurities can be obtained by sieving to remove metallic magnesium, or magnetically separating to remove iron powder mixed during pulverization and pulverization.
[0021]
The anhydrous magnesium chloride of the present invention produced as described above has very few impurities such as ammonia, and is suitable for olefin polymerization catalyst carriers and intermediate materials for pharmaceuticals, especially when used for olefin polymerization catalyst carriers. Thus, it is possible to obtain a catalyst having extremely high catalytic performance such as catalytic activity. The ammonia content in the obtained anhydrous magnesium chloride is 0.01% by weight or less, preferably 0.001% by weight.
It is as follows.
[0022]
Next, an apparatus for extracting molten magnesium chloride according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram of the apparatus for extracting molten magnesium chloride of this example, FIG. 2 is a diagram for explaining a method of cooling molten magnesium chloride in the first container, and FIG. 3 is a container sealing after solidification and before crushing It is a figure which shows the anhydrous magnesium chloride in a state. In FIG. 1, a molten magnesium chloride extraction device 1A includes a reduction furnace 2 for reducing titanium tetrachloride and metallic magnesium, a plurality of containers 3 for extracting and storing molten magnesium chloride generated in the reduction furnace 2, An extraction pipe 4 is provided.
[0023]
The extraction pipe 4 has one end 41 connected to the lower side of the reduction furnace 2 and extending upward, and the other end 42 bent from the upper position of the reduction furnace of the substantially vertical part 4a and extending obliquely downward. It is an inverted V-shaped circular pipe composed of a branched portion 4b arranged in the upper opening 31 of the first container 3a in the uppermost stream. The amount of molten magnesium chloride extracted from the reduction furnace 2 to the first container 3a can be adjusted by pressurizing the inside of the reduction furnace 2 and adjusting the pressure.
[0024]
The plurality of containers 3 are installed such that the downstream container is positioned lower than the nearest upstream container, and are communicated with each other by an overflow pipe. In this example, the plurality of containers 3 includes three containers, a first container 3a in the uppermost stream, a second container 3b in the middle, and a third container 3c in the most downstream, and each container is large. It is a 200 liter drum that has the same shape, and an opening 31a (31b, 31c) in which an extraction pipe or an overflow pipe is arranged is formed at the center of the top plate. And the 1st container 3a which has arranged the tip of extraction piping 4 from reduction furnace 2 is arranged in the highest position, and then the intermediate 2nd container 3b is arranged in a lower position than the 2nd container 3b. The third container 3c is disposed at a low position with a step. The diameter of the opening 31a of the first container 3a is slightly larger than the outer diameter of the branch portion 4b of the extraction pipe 4, so that when the extraction pipe is arranged in the opening 31a, a corner where air flows is formed. It has become. Moreover, the opening part 32a for discharging | emitting molten magnesium chloride from the 1st container 3a to the 2nd container 3b is provided in the side trunk | drum upper part of the 1st container 3a, and the said opening part 32a is provided. The other end of the downwardly inclined overflow pipe 6a having one end communicating with the upper opening 31b of the second container 3b is connected. By arranging in this way, the molten magnesium chloride discharged into the first container 3a is discharged into the second container 3b in a molten state. Moreover, the molten magnesium chloride arrange | positioned from the titanium reduction furnace to the 3rd container 3c can be continuously discharged | emitted from the 2nd container 3b by constructing the same structure in the 2nd container 3b.
[0025]
The third container 3c, that is, the container disposed at the most downstream side is provided with an opening 31c for receiving the molten magnesium chloride discharged from the second container, but the third container 3c is provided with a molten chloride. There is no pipe for discharging magnesium. However, it is preferable that the container arranged at the most downstream is placed on the pedestal 15 containing a load cell or the like in terms of avoiding problems such as overflow. Further, the vertical level of the opening 31a to the second container provided in the first container 3a and the sectional area of the opening are such that the bath level of the molten magnesium chloride discharged into the first container 3a is always the first container. Setting so that it is in a certain state filled with 3a can suppress the contact between the molten magnesium chloride extracted into the first container and the outside air as much as possible, and can further improve the quality. Is preferable.
[0026]
The position of the opening for receiving or discharging molten magnesium chloride in each container and the container structure are not particularly limited, but as long as the molten magnesium chloride is received in the container, the space in the container should be as small as possible. An arrangement or structure that can be discharged so as not to occur is preferable because the opportunity of contact between the atmosphere and molten magnesium chloride can be suppressed and contamination of magnesium chloride can be prevented.
[0027]
Next, a method for producing anhydrous magnesium chloride using the molten magnesium chloride extraction apparatus 1A of the present embodiment will be described. After reducing reaction of titanium tetrachloride and metal magnesium in the reduction furnace 2 to produce metal titanium and magnesium chloride, that is, extracting the magnesium chloride in a molten state as a by-product from the reduction furnace 2 after the reduction reaction is completed. 4 is extracted into the first container 3a. The extracted molten magnesium chloride is once discharged into the first container 3a, the level of the liquid rises, and when it reaches the opening 32a that communicates with the second container 3b, this time the molten magnesium chloride melts into the second container 3b. Magnesium chloride is automatically discharged. Next, similarly, when the liquid level of the second container 3b rises and reaches the opening 32b communicating with the third container 3c, the molten magnesium chloride is automatically discharged to the third container 3c. The
[0028]
The amount of molten magnesium chloride discharged to the container 3c is monitored by a load cell provided in the base 15 of the third container 3c, and when the predetermined value is reached, the extraction amount adjusting valve 7 is operated to stop the extraction. To do. Next, the molten magnesium chloride is solidified. At that time, if metallic magnesium is mixed in the molten magnesium chloride, it can be easily removed after solidification by allowing the molten metallic magnesium mixed before floating for a while to solidify. From the viewpoint that high-purity anhydrous magnesium chloride can be obtained.
[0029]
The solidification method of the molten magnesium chloride is not particularly limited, but as shown in FIG. 2, the cooling gas jet nozzles 10a to 10c are provided around the container 3a (3b, 3c), and argon gas or the like is supplied from there. The method of cooling the molten magnesium chloride by jetting it to the side surface of 3a is preferable in that the molten magnesium chloride can be solidified in a short time. If the time from the molten state to solidification is prolonged, oxygen or moisture in the atmosphere or atmospheric gas reacts with the molten magnesium chloride during that time to promote the generation of impurities, which is not preferable. In addition, once the surface layer portion of the molten magnesium chloride extracted into the container is solidified, the reaction with the atmospheric gas becomes slow, so an inexpensive gas such as nitrogen or air is used instead of the expensive argon gas. You can also. However, since moisture absorbs even solid magnesium chloride, it is preferable to use dehydrated gas if possible.
[0030]
The solidified magnesium chloride is preferably sealed for each container and taken out individually from the viewpoint of improving workability in the subsequent crushing step and crushing step. As a sealing method for each container, for example, the overflow pipes 6a and 6b connected to the opening of each container are cut in the vicinity of the opening, and then the opening is welded and joined with separate lid members 51 and 62. There is a method of sealing with a screw-type stopper or the like (see FIG. 3). Among these, the method of welding and joining is preferable in that air can be reliably prevented from entering the container. Sealing the solidified magnesium chloride is effective in that it can prevent the atmosphere from entering the interior during long-term storage and deterioration of the magnesium chloride due to oxidation or moisture absorption of the magnesium chloride. When sealing the container, it is preferable to use evacuation and argon gas replacement in combination. The solidified magnesium chloride sealed in each container is then crushed and then pulverized, and preferably pulverized to an average particle size of 100 μm or less. At this time, the metal magnesium is removed by further sieving.
[0031]
Next, an apparatus for extracting molten magnesium chloride according to the second embodiment of the present invention will be described with reference to FIG. 4, the same components as those in FIG. 1 are denoted by the same reference numerals, description thereof is omitted, and different points are mainly described. That is, FIG. 4 differs from FIG. 2 in that the entire three containers for extracting molten magnesium chloride are covered with the outer container 8, and the overflow pipe 6a is provided in the opening 31b of the second container 3b. The overflow pipe 6b is arranged in the opening 31c of the third container 3c. An inert gas is supplied to the outer container 8 from the outside into the outer container 8 and an opening 14 for inserting the branch portion 4b of the extraction pipe 4 that guides the molten magnesium chloride extracted from the reduction furnace 2. And an inert gas inlet 13 for the purpose. The opening 14 also functions as a discharge port through which the inert gas is discharged. In addition, it is preferable that the outer container 8 has a split structure that can be accommodated for each container because it is easy to dispose or remove a container for extracting molten magnesium chloride from the outer container. In the molten magnesium chloride extraction apparatus 1B, the installation of the external container 8 is effective in that the extraction atmosphere can be an atmosphere with as little water as possible, such as inert gas or dry air.
[0032]
The apparatus for extracting molten magnesium chloride of the present invention is not limited to the above embodiment, and for example, a circular arrangement structure as shown in FIG. 5 can be adopted as the arrangement of a plurality of containers. That is, the container arrangement structure of FIG. 5 differs from the container arrangement structure of FIG. 1 in that FIG. 1 is a linear arrangement of three containers, whereas FIG. 5 is a circular arrangement of five containers 3a to 3e. This is the point. That is, the molten magnesium chloride extracted from the reduction furnace is sequentially discharged from the first container 3a to the fifth container 3e through the overflow pipes 6a to 6d into a circularly arranged container, and a predetermined amount of molten chloride is obtained. When the magnesium is extracted, the extraction amount adjusting valve 7 is operated to complete the extraction of the molten magnesium chloride. In addition, although each container may be arrange | positioned on the same horizontal surface, as shown in FIG. 1 or FIG. 4, it can extract smoothly molten magnesium chloride by providing a level | step difference in a perpendicular direction. Further, by arranging as shown in FIG. 5, it is possible to proceed with the extraction work in a space-saving manner as compared with FIG. 1 and FIG. 4.
[0033]
Further, in the molten magnesium chloride extraction apparatus of the present invention, the connection form of the plurality of containers may be a parallel connection as shown in FIG. 6 in addition to the serial connection as shown in the above embodiment. That is, the parallel connection in FIG. 6 has a structure in which a manifold 61 having five branch pipes 61a to 61e that can be simultaneously drawn into five containers at the tip of the extraction pipe 4 is provided. By arranging in this way, molten magnesium chloride can be extracted in a relatively short time.
[0034]
In the molten magnesium chloride extraction device of the present invention, it is also preferable that a weighing device such as a load cell is provided at the bottom of all of the plurality of containers. The container is preferably made of a material that can withstand corrosion caused by solid magnesium chloride. For example, stainless steel is preferably used. However, when it is required to maintain higher quality, it is more preferable to use a titanium material in terms of light weight or corrosion resistance.
[0035]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, this is merely an example and does not limit the present invention.
Example 1
The molten magnesium chloride at about 900 ° C. produced as a by-product by the reaction between titanium tetrachloride and molten magnesium in the titanium reduction furnace was extracted into a container and solidified by cooling. The containers were in the form of drums, and five of these were arranged in series. Further, each container was connected to each other via an overflow pipe, and then the whole was stored in an external container. That is, the apparatus has the structure shown in FIG. 4 except that the number of the three containers is five. While supplying argon gas to the external container, a total of 1500 kg of magnesium chloride was extracted into five containers. Even after extraction, molten magnesium chloride was solidified while circulating argon gas in the external container, and cooled to room temperature. Thereafter, the opening of the container was sealed by welding. Before sealing, anhydrous magnesium chloride extracted from the container was sampled to analyze the impurity components. The results are shown in Table 1.
[0036]
Comparative Example 1
Magnesium chloride discharged from the same titanium reduction furnace as in Example 1 was once extracted into a magnesium chloride container, and then extracted one by one into the same five containers used in Example 1. The extraction weight per container was about 300 kg. The extraction work to the container and the extraction work from the container to the container were performed in the atmosphere. In the same manner as in Example 1, anhydrous magnesium chloride was sampled and analyzed. The results are shown in Table 1.
[0037]
[Table 1]

[0038]
It can be seen that the anhydrous magnesium chloride of Example 1 produced by the method of the present invention is higher in purity than the comparative example 1, and particularly has very little ammonia component.
[0039]
Example 2
Using the anhydrous magnesium chloride obtained in Example 1, an olefin polymerization catalyst was prepared as follows, and propylene polymerization was evaluated.
(Preparation of solid catalyst component)
The massive anhydrous magnesium chloride obtained in Example 1 was crushed and then pulverized in a vibration mill for 2 hours. The thus obtained anhydrous magnesium chloride (30 g), titanium tetrachloride (2.3 ml) and di-n-butyl phthalate (3.0 ml) were filled in a vibration mill sufficiently substituted with nitrogen gas and co-ground for 17 hours to obtain a solid. A catalyst component was prepared.
(Formation of polymerization catalyst and polymerization)
An autoclave with a stirrer having an internal volume of 2.0 liters that was completely replaced with nitrogen gas was charged with 1.32 mmol of triethylaluminum, 0.13 mmol of cyclohexylmethyldimethoxysilane, and 0.0026 mmol of the solid catalyst component as titanium atoms. A polymerization catalyst was formed. Thereafter, 2.0 liters of hydrogen gas and 1.4 liters of liquefied propylene were charged, preliminarily polymerized at 20 ° C. for 5 minutes, then heated, and polymerized at 70 ° C. for 1 hour. Table 2 shows the polymerization activity per gram of the solid catalyst component at this time, the ratio (HI) of boiling n-heptane insoluble matter in the produced polymer, and the melt index value (MFR).
[0040]
The polymerization activity per solid catalyst component used here was calculated by the following equation.
Polymerization activity = produced polymer (g) / solid catalyst component (g)
Moreover, the ratio (HI) of the boiling insoluble n-heptane in the produced polymer is the ratio of the polymer insoluble in n-heptane when the produced polymer is extracted with boiling n-heptane for 6 hours (wt%). ). Further, the melt index value (MFR) of the produced polymer was measured according to ASTM D1238 or JIS K7210, and the bulk specific gravity (BD) was measured according to JIS K6721.
[0041]
Comparative Example 2
The experiment was performed in the same manner as in Example 2 except that anhydrous magnesium chloride produced in Comparative Example 1 was used. The obtained results are shown in Table 2.
[0042]
[Table 2]

[0043]
【The invention's effect】
According to the production method of the present invention, it is possible to obtain anhydrous magnesium chloride having a high purity and particularly an extremely small amount of mixed ammonia, and particularly anhydrous magnesium chloride suitable for an olefin polymerization catalyst carrier. In addition, according to the molten magnesium chloride extraction apparatus of the present invention, the manufacturing method of the present invention can be reliably implemented with a simple structure and no installation place.
[Brief description of the drawings]
FIG. 1 is a schematic view of a molten magnesium chloride extraction apparatus according to a first embodiment.
FIG. 2 is a diagram illustrating a method for cooling molten magnesium chloride in a first container.
FIG. 3 is a diagram for explaining a sealed state in a container after solidification and before crushing.
FIG. 4 is a schematic view of an apparatus for extracting molten magnesium chloride according to a second embodiment.
FIG. 5 is a view showing another arrangement form of a plurality of containers.
FIG. 6 is a view showing another arrangement form of a plurality of containers.
[Explanation of symbols]
1A, 1B Molten magnesium chloride extraction device
2 Reduction furnace
3 Multiple containers
3a-3e container
4 Extraction piping
6a-6e Overflow piping
8 External container
10a to 10c Cooling gas jet nozzle
11 Molten magnesium chloride
12 Titanium metal and magnesium chloride
15 Pedestal in the load cell
16 solidified anhydrous magnesium chloride

Claims (12)

Titanium tetrachloride and metallic magnesium in the reduction furnace by the reduction reaction, after reduction reaction ends to produce a metallic titanium and magnesium chloride, extracted directly the salt of magnesium in a molten state into the container from the reducing furnace, said container A method for producing anhydrous magnesium chloride characterized by solidifying with The method for producing anhydrous magnesium chloride according to claim 1, wherein the amount of molten metal magnesium in the molten magnesium chloride withdrawn from the reduction furnace is 0.1 wt% or less. Claim 1 or 2 method for producing anhydrous magnesium chloride, wherein said container is a container communicating with the two or more mutually. The two or more containers are installed such that the downstream container is located at a lower position than the nearest upstream container, and the molten magnesium chloride extracted into the first container in the uppermost stream is discharged by an overflow pipe. the second claim 1-3 any one method for producing anhydrous magnesium chloride according to, characterized in successively withdrawing it after the container is communicated. When withdrawn directly from the reducing furnace said salt of magnesium in the molten state in a container, according to claim 1-4 any one method for producing anhydrous magnesium chloride according to, characterized in that to carry out in an inert gas atmosphere. 6. The molten magnesium chloride is directly extracted from the reduction furnace into the container, and then molten metal magnesium mixed before solidification is floated, and the metal magnesium is removed after solidification . The method for producing anhydrous magnesium chloride according to any one of the above. After solidification withdrawn directly magnesium chloride in a molten state into the container from the reduction furnace, and then disintegrated, then production method of anhydrous magnesium chloride in any one of claims 1-6, characterized in that grinding . The molten magnesium chloride is directly extracted from the reducing furnace into a container, solidified, crushed, then pulverized to an average particle size of 100 µm or less, and further screened to remove metallic magnesium. any one anhydride method for producing a magnesium chloride according the to 7. The method for producing anhydrous magnesium chloride according to claim 1, wherein the anhydrous magnesium chloride is for an olefin polymerization catalyst carrier. A reduction furnace for reducing and reacting titanium tetrachloride and metallic magnesium, a plurality of containers for extracting molten magnesium chloride generated in the reduction furnace, containing the molten magnesium chloride and solidifying, and one end of the reduction furnace Connected to the upper end of the first container having the other end in the uppermost stream, and the plurality of containers are lower in the downstream container than the nearest upstream container It is disposed to come to the position, withdrawal apparatus for molten magnesium chloride, characterized in that each other is communicated by an overflow pipe. The molten magnesium chloride extraction apparatus according to claim 10 , further comprising an external container that accommodates the plurality of containers and has a nozzle for introducing and discharging argon gas or dry air. The apparatus for extracting molten magnesium chloride according to claim 10 or 11 , wherein a load cell is provided at least on the pedestal of the container at the most downstream side.

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