JPH0542365B2 - - Google Patents
Info
- Publication number
- JPH0542365B2 JPH0542365B2 JP61215154A JP21515486A JPH0542365B2 JP H0542365 B2 JPH0542365 B2 JP H0542365B2 JP 61215154 A JP61215154 A JP 61215154A JP 21515486 A JP21515486 A JP 21515486A JP H0542365 B2 JPH0542365 B2 JP H0542365B2
- Authority
- JP
- Japan
- Prior art keywords
- graphite
- wood
- natural graphite
- dust
- test
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 33
- 229910002804 graphite Inorganic materials 0.000 claims description 30
- 239000010439 graphite Substances 0.000 claims description 30
- 229910021382 natural graphite Inorganic materials 0.000 claims description 12
- 239000002023 wood Substances 0.000 claims description 11
- 239000000428 dust Substances 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 5
- 238000005188 flotation Methods 0.000 claims description 4
- 230000003647 oxidation Effects 0.000 claims description 4
- 238000007254 oxidation reaction Methods 0.000 claims description 4
- 239000002893 slag Substances 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 150000007522 mineralic acids Chemical class 0.000 claims description 2
- 239000007800 oxidant agent Substances 0.000 claims description 2
- 238000005554 pickling Methods 0.000 claims description 2
- 238000012360 testing method Methods 0.000 description 9
- 238000000034 method Methods 0.000 description 8
- 239000000047 product Substances 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 7
- 230000006835 compression Effects 0.000 description 6
- 238000007906 compression Methods 0.000 description 6
- 238000012856 packing Methods 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000011084 recovery Methods 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 230000036316 preload Effects 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910010272 inorganic material Inorganic materials 0.000 description 2
- 239000011147 inorganic material Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000010452 phosphate Substances 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000011121 hardwood Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- -1 natural graphite Chemical compound 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000012264 purified product Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000012353 t test Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000012085 test solution Substances 0.000 description 1
Landscapes
- Carbon And Carbon Compounds (AREA)
Description
〔産業上の利用分野〕
本発明は、膨張黒鉛の製造方法に係り、特にキ
ツシユ黒鉛と天然黒鉛とから製造する方法に関す
る。
〔従来の技術〕
膨張黒鉛は、耐熱性に優れ、成形性が良好であ
るなどの点から、パツキン、パイプシーライト、
バルブシートやガスケツト等に使用されている。
この膨張黒鉛は、天然黒鉛、熱分解黒鉛、キツ
シユ黒鉛等の黒鉛を、濃酸と酸塩との混合溶液で
処理し、水洗、乾燥などの処理後、加熱処理する
ことによつて得られる。
従来、この種の膨張黒鉛の改良された製造法と
して、いくつかの提案がなされており、たとえば
(1)特公昭57−56512号公報では、上記のように得
られた膨張黒鉛に耐熱無機材料添加し、パツキン
材として用いることが示され、(2)特公昭54−
30678号公報には、黒鉛を混酸にて酸化処理し、
水洗した後、リン酸またはリン酸塩にて酸化抑制
処理し、20〜70倍に加熱膨張処理することが教示
され、(3)特開昭54−38292号公報には、黒鉛をオ
ペルオキソー硫酸によつて処理することによつて
酸化力の向上と黒鉛の層間に重硫酸根を挿入する
ことが開示されている。
〔発明が解決しようとする問題点〕
膨張黒鉛は、前述のようにパツキン等に最終的
に使用されるが、シールのために締込んだときの
復元率（圧縮率）、自動車エンジン周り等の高温
下条件での耐熱性、化学プラント用などに対する
耐薬品性が要求されるが、製造コストを考慮した
条件下で十分な特性を得られていないのが実情で
ある。
例えば(1)の方法では、膨張黒鉛と耐熱無機材料
とを混合するに際して、相互に粒度、形状が異な
るため均一混合が難しく、製品自体も不均一で、
かつ優れた物性が得られないと考えられる。(2)の
方法では、膨張率を下げるため、リン酸またはリ
ン酸塩によつて酸化抑制処理を必須としており、
経済的でない、さらに(3)の方法では、酸化条件下
で通常20〜30℃程度の低温に保持する必要がある
が、実用上この条件保持は難しい。
そこで、本発明は、製造法として、簡易かつ経
済的でありながら、優れた物性の製品を得ること
ができる膨張黒鉛の製造方法を提供することにあ
る。
〔問題点を解決するための手段〕
上記問題点を解決するための本発明は、溶融金
属中より析出したキツシユをスラグまたはダスト
の少くとも１つとして回収後、浮選および酸洗い
によつて精製し炭素含有率が90％以上のキツシユ
黒鉛を得、これと天然黒鉛とを30〜70％の割合で
混合し、酸化剤の存在下で無機強酸により酸化処
理した後、800℃以上の加熱処理によつて膨張さ
せることを特徴とするものである。
〔作用〕
上述のように、パツキンとしては、復元率、耐
熱性および耐薬品性に優れることが要求される。
しかるに、前記各公報の実施例のいずれも、天然
黒鉛を出発物質としているが、天然物質を基礎と
する限り、後記実施例のように、耐薬品性が悪い
し、また価格も高い。一方で、キツシユ黒鉛のみ
であると、耐酸化性（耐熱性）が悪い。
そこで、本発明に従つて、キツシユ黒鉛と天然
黒鉛とを併用することとすると、上記要求される
特性の全てを満すことができるとともに、併用に
伴つて、各単味によるものと比較して、圧縮後の
復元率を高めることができる。
他方で、キツシユ黒鉛および天然黒鉛は、形状
および粒度共に大差がないので、これらを混合す
るとき何ら支障なく混合でき、均質な製品とする
ことができる。また、前記(2)及び(3)の方法におけ
る特別な処理は条件設定を行わなくとも、通常の
処理方式で十分な結合性を示す。
〔発明の具体的構成〕
以下本発明をさらに詳説する。
本発明では、製鉄過程に由来するキツシユを精
製したキツシユ黒鉛をまず用意する。製鉄所で
ほ、脱硫、脱燐、脱珪のための溶銑予備処理が、
近年特に汎用されているが、その際の集塵ダスト
やスラグを回収して、溶融金属（溶銑）中より析
出したキツシユを得る。回収方法としては、適宜
の公知の方法によればよく、またダストおよびス
ラグの両者から回収してもよい。
たとえば、予銑予備処理時の集塵ダストの組成
は、第１表の通りであり、また密度は２〜３ｇ／
c.c.程度である。
[Industrial Application Field] The present invention relates to a method for producing expanded graphite, and particularly to a method for producing expanded graphite from wood graphite and natural graphite. [Conventional technology] Expanded graphite has excellent heat resistance and good moldability, so it is used in packing, pipe sealite,
Used for valve seats, gaskets, etc. This expanded graphite can be obtained by treating graphite such as natural graphite, pyrolytic graphite, and hardwood graphite with a mixed solution of a concentrated acid and an acid salt, washing with water, drying, etc., and then heat-treating. In the past, several proposals have been made as improved production methods for this type of expanded graphite, such as:
(1) Japanese Patent Publication No. 57-56512 discloses that expanded graphite obtained as described above is added with a heat-resistant inorganic material and used as a packing material; (2) Japanese Patent Publication No. 54-56
Publication No. 30678 discloses that graphite is oxidized with a mixed acid,
After washing with water, it is taught that graphite is treated with phosphoric acid or phosphate to inhibit oxidation, and then thermally expanded 20 to 70 times. It is disclosed that the oxidizing power is improved and bisulfate radicals are inserted between the layers of graphite through such treatment. [Problems to be solved by the invention] As mentioned above, expanded graphite is ultimately used for packing, etc., but it has a high recovery rate (compression rate) when tightened for sealing, and a problem with parts such as those around automobile engines. Heat resistance under high-temperature conditions and chemical resistance for use in chemical plants are required, but the reality is that sufficient properties have not been obtained under conditions that take manufacturing costs into consideration. For example, in method (1), when mixing expanded graphite and a heat-resistant inorganic material, it is difficult to mix them uniformly because their particle sizes and shapes differ, and the product itself is non-uniform.
Moreover, it is considered that excellent physical properties cannot be obtained. Method (2) requires oxidation suppression treatment with phosphoric acid or phosphate to reduce the expansion rate.
In method (3), which is not economical, it is necessary to maintain the temperature at a low temperature of usually about 20 to 30°C under oxidizing conditions, but it is difficult to maintain this condition in practice. SUMMARY OF THE INVENTION Therefore, the present invention provides a method for producing expanded graphite that is simple and economical and can produce products with excellent physical properties. [Means for Solving the Problems] The present invention aims to solve the above-mentioned problems by recovering the debris precipitated from the molten metal as at least one of slag or dust, and then recovering it by flotation and pickling. Refined Kitshu graphite with a carbon content of 90% or more is obtained, mixed with natural graphite at a ratio of 30 to 70%, oxidized with a strong inorganic acid in the presence of an oxidizing agent, and then heated to 800°C or more. It is characterized by being expanded through processing. [Function] As mentioned above, the packing is required to have excellent recovery rate, heat resistance, and chemical resistance.
However, all of the examples in the above-mentioned publications use natural graphite as a starting material, but as long as they are based on natural materials, they have poor chemical resistance and are expensive, as in the examples described later. On the other hand, if only hard graphite is used, oxidation resistance (heat resistance) is poor. Therefore, in accordance with the present invention, by using Kizushi graphite and natural graphite in combination, it is possible to satisfy all of the above-mentioned required properties, and when they are used in combination, compared to using each of them alone, , it is possible to increase the decompression rate after compression. On the other hand, since there is not much difference in shape and particle size between Kitshu graphite and natural graphite, they can be mixed without any problem and a homogeneous product can be obtained. Further, the special processing in methods (2) and (3) above shows sufficient connectivity in a normal processing method without setting conditions. [Specific Structure of the Invention] The present invention will be explained in further detail below. In the present invention, wood graphite obtained by refining wood derived from the iron manufacturing process is first prepared. At steelworks, hot metal pretreatment for desulfurization, dephosphorization, and desiliconization is
It has become particularly popular in recent years, and the collected dust and slag are collected to obtain wood precipitated from the molten metal (hot metal). The collection method may be any suitable known method, and may be collected from both dust and slag. For example, the composition of the dust collected during pre-iron pretreatment is as shown in Table 1, and the density is 2 to 3 g/
It is about cc.
【表】
このキツシユ原料は、たとえばまず、公知の方
式で浮選（浮遊選鉱）し、塩酸等による酸処理
後、水洗脱水し、キツシユ黒鉛とすることができ
る。
この精製によつて、密度が0.1〜１ｇ／c.c.程度
の第２表の組成例の精製品を得る。[Table] This wood grain raw material can be made into wood graphite by first flotation (flotation) using a known method, followed by acid treatment with hydrochloric acid or the like, followed by washing and dehydration. Through this purification, a purified product having a density of about 0.1 to 1 g/cc and having a composition example shown in Table 2 is obtained.
【表】
この場合、精製キツシユ黒鉛としては、その炭
素含有率が90％以上であることが、最終製品（た
とえばパツキン）の特性を高める上で望まれる。
一方で、本発明では、キツシユ黒鉛のみでな
く、天然黒鉛も使用される。天然黒鉛としては、
各地産のものを使用でき、その例を第３表に示
す。[Table] In this case, it is desirable for the refined wood graphite to have a carbon content of 90% or more in order to improve the properties of the final product (for example, packing). On the other hand, in the present invention, not only wood graphite but also natural graphite is used. As natural graphite,
Various local products can be used, examples of which are shown in Table 3.
次に実施例によつて、本発明の効果を明らかに
する。
溶銑予備処理後、溶銑台車から鍋に受ける時の
ダストを集塵し、この集塵ダストを回収し、第１
図に示す工程を経て精製し、第２表の組成の精製
キユシユ黒鉛を得、これをスリランカ産天然黒鉛
と、10％ごと配合割合を変えて混合し、各混合物
を第１図の工程に則つて処理し、シート状物を得
た。
この各シート状物からテスト片を採取した。こ
れらテスト片について、次の試験を行つた。
＜耐薬品性＞
50L×25Wmmのテスト片を試験後に５時間浸漬
し、その後これを取り出し、表面の水滴を濾紙で
拭き取り、厚さＴおよび重さＷの変化を調べる。
用いた薬品は、第２〜５図のように４種で、硝酸
については室温とする以外は、全て50〜60℃の試
験液とした。
＜加熱減量試験＞
50L×25W×1tのテスト片の重量も前もつて秤
量し、Waとする。磁製ルツボに入れ、電気炉で
450℃×24hr又は600℃×0.5hr酸化性雰囲気で加
熱し、0.5hr放冷後秤量しWbとし、(1)式によつて
加熱減量を求める。
加熱減量（％）＝Wa−Wb／Wa×100……(1)
＜圧縮・復元試験＞
１片２×25mmの四角形のテスト片１ケを中心を
合せて挟み、予荷重７Kg／cm215秒間加え、厚味
T1（mm）を1/100mmまで読み、次に10秒間以内に
全荷重350Kg／cm2になるよう予荷重の上へ圧縮し、
60秒後、厚さT2（mm）を1/100mmまて読む。
厚さT2測定後、直ちに予荷重まで戻し、60秒
後、厚さT3（mm）を読み、圧縮率、復元率を(2)、
(3)式によつて求める（JIS R3543テスト法より）。
圧縮率（％）＝T1−T2／T1×100……(2)
復元率（％）＝T3−T2／T1−T2×100 ……(3)
＜考察＞
耐薬品性の結果を第２〜５図に、耐加熱性の結
果を第６図、圧縮性および復元率の結果を第７図
にそれぞれ示した。
耐薬品性については、キツシユ黒鉛の割合が多
い程すぐれ、キツシユ黒鉛／天然黒鉛の比率が
７／３以下であると低下傾向にあるが、３／７程
度までは実用上十分である。加熱減量について
は、約７／３〜６／４程度から良好になる。圧縮
率は有意差がない反面、復元率は85／15以下で実
用上十分であり、特に７／３〜３／７程度が良好
である。
〔発明の効果〕
以上の通り、本発明によれば、格別実用上問題
のある処理を経ることなく、通常の処理をもつて
製造できるとともに、キツシユ黒鉛および天然黒
鉛単味の場合より、優れた特性の製品を得ること
ができる膨張黒鉛が得られる。
Next, the effects of the present invention will be clarified through examples. After the hot metal pretreatment, the dust from the hot metal truck to the pot is collected, the collected dust is collected, and the first
Purified through the steps shown in the figure to obtain purified Kyushu graphite with the composition shown in Table 2. This was mixed with Sri Lankan natural graphite at varying proportions of 10%, and each mixture was prepared according to the process shown in Figure 1. A sheet-like product was obtained. A test piece was taken from each sheet. The following tests were conducted on these test pieces. <Chemical Resistance> A test piece of 50 L x 25 W mm was immersed for 5 hours after the test, then taken out, water droplets on the surface were wiped off with a filter paper, and changes in thickness T and weight W were examined.
Four types of chemicals were used, as shown in Figures 2 to 5, and all test solutions were at 50 to 60°C, except for nitric acid, which was at room temperature. <Heating loss test> The weight of a 50 L x 25 W x 1 t test piece was also weighed in advance and set as Wa. Place it in a porcelain crucible and heat it in an electric furnace.
Heate in an oxidizing atmosphere at 450°C for 24 hours or 600°C for 0.5 hours, and after allowing it to cool for 0.5 hours, weigh it to determine Wb, and calculate the loss on heating using equation (1). Heating loss (%) = Wa - Wb / Wa × 100... (1) <Compression/restitution test> One square test piece of 2 x 25 mm is sandwiched with the center aligned, and a preload of 7 Kg/cm 2 15 Add for a second, thick taste
Read T 1 (mm) to 1/100mm, then compress it above the preload to a total load of 350Kg/cm 2 within 10 seconds,
After 60 seconds, read the thickness T 2 (mm) to 1/100mm. After measuring the thickness T 2 , immediately return it to the preload, and after 60 seconds, read the thickness T 3 (mm), and calculate the compression ratio and recovery ratio (2),
Calculate using formula (3) (from JIS R3543 test method). Compression rate (%) = T 1 - T 2 / T 1 × 100 ... (2) Restoration rate (%) = T 3 - T 2 / T 1 - T 2 × 100 ... (3) <Consideration> Chemical resistance The results of heat resistance are shown in Figures 2 to 5, the results of heat resistance are shown in Figure 6, and the results of compressibility and recovery rate are shown in Figure 7. Regarding chemical resistance, the higher the ratio of hard graphite, the better it is, and if the ratio of hard graphite/natural graphite is less than 7/3, it tends to decrease, but it is practically sufficient up to about 3/7. The loss on heating becomes good from about 7/3 to 6/4. While there is no significant difference in the compression ratio, the restoration ratio is 85/15 or less, which is sufficient for practical use, and in particular, about 7/3 to 3/7 is good. [Effects of the Invention] As described above, according to the present invention, it is possible to produce the product through normal processing without undergoing any treatment that poses any particular practical problems, and it is also possible to produce the product through normal processing, which is superior to the case of wood graphite and natural graphite alone. Expanded graphite is obtained from which products with characteristics can be obtained.
第１図は本発明の製造工程例図、第２図〜第７
図は試験結果図である。
Figure 1 is an example of the manufacturing process of the present invention, Figures 2 to 7
The figure shows the test results.
Claims (1)
たはダストの少くとも１つとして回収後、浮選お
よび酸洗いによつて精製し炭素含有率が90％以上
のキツシユ黒鉛を得、これと天然黒鉛とを30〜70
％の割合で混合し、酸化剤の存在下で無機強酸に
より酸化処理した後、800℃以上の加熱処理によ
つて膨張させることを特徴とする膨張黒鉛の製造
方法。1 After recovering the wood precipitated from the molten metal as at least one of slag or dust, it is purified by flotation and pickling to obtain wood graphite with a carbon content of 90% or more, and this is combined with natural graphite. 30-70
%, oxidation treatment with a strong inorganic acid in the presence of an oxidizing agent, and then expanding by heat treatment at 800°C or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61215154A JPS6369705A (en) | 1986-09-12 | 1986-09-12 | Production of expanded graphite |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61215154A JPS6369705A (en) | 1986-09-12 | 1986-09-12 | Production of expanded graphite |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6369705A JPS6369705A (en) | 1988-03-29 |
| JPH0542365B2 true JPH0542365B2 (en) | 1993-06-28 |
Family
ID=16667559
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61215154A Granted JPS6369705A (en) | 1986-09-12 | 1986-09-12 | Production of expanded graphite |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6369705A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02188418A (en) * | 1989-01-17 | 1990-07-24 | Nippon Kasei Kk | Thermally expandable graphite |
| US6406612B1 (en) | 1999-05-20 | 2002-06-18 | Graftech Inc. | Expandable graphite and method |
| US6669919B1 (en) | 2000-11-16 | 2003-12-30 | Advanced Energy Technology Inc. | Intercalated graphite flakes exhibiting improved expansion characteristics and process therefor |
| CN103738955A (en) * | 2014-01-13 | 2014-04-23 | 清华大学 | Expanded graphite environment-friendly material with Kish graphite as raw material as well as preparation method and application thereof |
| WO2019220176A1 (en) * | 2018-05-16 | 2019-11-21 | Arcelormittal | A method for the manufacture of graphene oxide from kish graphite |
| WO2019220174A1 (en) | 2018-05-16 | 2019-11-21 | Arcelormittal | A method for the manufacture of pristine graphene from kish graphite |
| WO2019224579A1 (en) | 2018-05-23 | 2019-11-28 | Arcelormittal | A method for the manufacture of reduced graphene oxide from electrode graphite scrap |
| CN110092375B (en) * | 2019-06-11 | 2022-08-30 | 张学忠 | Processing method of expandable graphite without wastewater and waste residue discharge |
-
1986
- 1986-09-12 JP JP61215154A patent/JPS6369705A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6369705A (en) | 1988-03-29 |
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