JPS6065097A - Improvement of coal - Google Patents

Abstract

PURPOSE:To obtain formed coal having excellent water resistance and a high crushing strength after immersion in water, by heating fully dried coal rapidly, compression-molding it and subjecting formed coal to oxidation and steaming. CONSTITUTION:Low-grade coal such as peat, brown coal or (sub-) bituminous coal is crushed to a particle size smaller than 3mm. and is dried at 85-150 deg.C in an inert gas atmosphere until its water content is reduced to 0%. The dried coal is rapidly heated to a predetermined forming temp. (200-400 deg.C) within 10min and compression-molded at that temp. under a pressure of 1-5t/cm<2>. The resultant formed coal is heated for oxidation at 100-200 deg.C for 30min-5hr in an atmosphere having an oxygen concn. of 1-2vol% and is then treated with satd. steam at 80-150 deg.C for 2-8hr. EFFECT:The formed coal has a crushing strength of 100kg.f/cm or higher after immersion in water for 100hr.

Description

【発明の詳細な説明】 本発明は石炭の改質方法に関し、詳しくは泥炭。[Detailed description of the invention] The present invention relates to a method for reforming coal, particularly peat.

褐炭、亜瀝青炭などの低品位炭の耐水性および水中浸漬
後の圧潰強度を向上させると共に、含水率を低減させ、
かつ活性を低下させて自然発火の防止を図シ、輸送性、
貯蔵性を向上させる石炭の改質方法に関する。Improves the water resistance and crushing strength of low-grade coal such as brown coal and sub-bituminous coal after immersion in water, and reduces the water content.
It also reduces activity and prevents spontaneous combustion, improves transportability,
This invention relates to a method for reforming coal to improve its storability.

褐炭などの低品位炭は含水率が高いため、その輸送が不
経済であるばかシでなく、活性が強いため輸送中や貯蔵
中などに自然発火を起こし易い等の理由で１その利用範
囲は山元近傍に限られている。Since low-grade coal such as lignite has a high moisture content, it is not uneconomical to transport it, but its use is limited because it is highly active and tends to spontaneously ignite during transportation or storage. It is limited to the vicinity of Yamamoto.

このような事情に鑑み、これら低品位炭の脱水および自
然発火の防止に関する研究が行なわれ、種々の提案がな
されている。たとえば、脱水法としては■蒸発法、■機
械的脱水法などが知られておシ、また自然発火防止法と
しては■空気遮断法（水中貯炭１石炭表面コーティング
、貯炭表面被覆、圧縮貯炭、不活性ガスシールなど）、
■冷却流、■微粉炭の除去、■ブリケット化などの対策
が行なわれている。具体的には乾燥後水蒸気存在下で加
熱処理し、大気圧下で加熱成形して練炭とする方法（特
開昭５６−１０４９９６号公報）、乾燥後急速加熱し、
次いで急速冷却する方法（特開昭５６−１４９４９４号
公報）などがある。In view of these circumstances, research has been conducted on dehydration of these low-rank coals and prevention of spontaneous combustion, and various proposals have been made. For example, known dehydration methods include ■evaporation method and ■mechanical dehydration method, and methods for preventing spontaneous ignition include ■air blocking method (underwater coal storage 1 coal surface coating, coal storage surface coating, compressed coal storage, active gas seal, etc.),
Countermeasures such as ■cooling flow, ■removal of pulverized coal, and ■briquetting are being taken. Specifically, after drying, heat treatment is performed in the presence of steam, followed by heat molding under atmospheric pressure to form briquettes (Japanese Unexamined Patent Publication No. 56-104996), rapid heating after drying,
Then, there is a method of rapid cooling (Japanese Unexamined Patent Publication No. 149494/1984).

しかしながら、これらの方法は十分な効果が得られなか
ったシー操作が煩雑であったりして必ずしも満足すべき
方法ではなかった。However, these methods are not necessarily satisfactory because sufficient effects cannot be obtained and the sea operations are complicated.

そこで本発明者らは既に高温下に圧縮成形する方法（％
願昭５７−３２９８５号明ｍ書）、乾燥後原料炭を酸化
処理して自然発火を防止する方法（特願昭５７−１８２
７８９号明細書）を提案している・さらに続けて本発明
者らは石炭を実質的に含水率０％になるまで乾燥し、次
いで成形温度まで急速加熱し、高圧下で圧縮成形し、成
形物を酸化処理する方法（特願昭５８−３５９２８号明
細書）を提案している。Therefore, the present inventors have already developed a method of compression molding under high temperature (%
Patent Application No. 57-32985), Method for Preventing Spontaneous Ignition by Oxidizing Raw Coal after Drying
789 specification).Furthermore, the present inventors dried the coal until the moisture content was substantially 0%, then rapidly heated it to the molding temperature, compression molded it under high pressure, and molded it. He has proposed a method for oxidizing materials (Japanese Patent Application No. 58-35928).

本発明者らは、さらに低品位炭の改質方法について改良
を重ねた結果、上記酸化処理後にスチーム処理を行なう
ことによシ、成形炭の耐水性および水中浸漬後の圧潰強
度を一層向上させることができることを見出し、本発明
を完成するに到った。As a result of further improvements in the method for reforming low-rank coal, the present inventors have found that by performing steam treatment after the oxidation treatment, the water resistance of the briquette coal and the crushing strength after immersion in water are further improved. The inventors have discovered that it is possible to do so, and have completed the present invention.

すなわち、本発明は石炭を実質的に含水率０％になるま
で乾燥後、成形温度まで急速加熱し、高圧下で圧縮成形
し、得られた成形物を酸化処理し、次いでスチーム処理
することを特徴とする石炭の改質方法を提供するもので
ある。That is, the present invention involves drying coal to a water content of substantially 0%, rapidly heating it to a molding temperature, compression molding it under high pressure, oxidizing the resulting molded product, and then steaming it. The present invention provides a coal reforming method with characteristics.

石炭の中では泥炭が最も自然発火しやすく、以下褐炭、
亜瀝青炭、瀝青炭の順であることが知られている。また
、泥炭、褐炭９Ｍ瀝青炭、瀝青炭などの低品位炭は含水
率が高いため、輸送効率が悪いものである。したがって
、本発明では主としてこれらの低品位炭を対象としてそ
の改質を行なうものである。Among coals, peat is the most likely to spontaneously ignite;
It is known that the order is sub-bituminous coal and then bituminous coal. In addition, low-grade coal such as peat, lignite 9M bituminous coal, and bituminous coal has a high moisture content and therefore has poor transportation efficiency. Therefore, in the present invention, these low-rank coals are mainly targeted for modification.

本発明を実施するにあたって、原料炭は予め粉砕して粒
状としておくことが望ましく、特に粒径を３１１ＯＩ＋
以下としておくことが好ましい。また、石炭は天日乾燥
などＫよシ乾燥して含水率を１５〜２０重景％ま重量減
さ也ることが望ましい。In carrying out the present invention, it is desirable to crush the raw coal in advance into granules, and in particular, the particle size is 311 OI+
It is preferable to keep the following. It is also desirable to reduce the weight of the coal by drying it in the sun to reduce its moisture content to 15-20%.

石炭の乾燥は、通常８５〜１５０℃の温度で加熱するこ
とにより行ない、好ましくは窒素ガス等の不活性ガス中
で、実質的に含水率が０％となるまで行なう。乾燥時間
は石炭の種類、加熱温度などを考慮して決定する。この
乾燥によシ石炭中の水分の大部分が除かれ、さらに可燃
性ガスの一部も除去される。Drying of coal is usually carried out by heating at a temperature of 85 to 150°C, preferably in an inert gas such as nitrogen gas, until the moisture content becomes substantially 0%. The drying time is determined by considering the type of coal, heating temperature, etc. This drying removes most of the moisture in the coal and also removes some of the combustible gases.

乾燥した石炭は、次に高温度、好ましく＆ま２００〜４
００°Ｃの温度まで急速にｊＪＵｌｒ熱する。所定温度
まで１０分以内、好ましくは５〜７分で急速加熱する。The dried coal is then heated to a high temperature, preferably &amp;
Heat rapidly to a temperature of 00°C. Rapid heating is performed to a predetermined temperature within 10 minutes, preferably within 5 to 7 minutes.

このような急速加熱を行なうの＆よ、高温で長時間処理
することによる成形性の低下を防止するためである。The purpose of such rapid heating is to prevent deterioration in moldability due to long-term treatment at high temperatures.

急速加熱後、その所定ｓＭ１好ましく＆ま２００〜４０
０℃の温度において１〜５ｔ／ａｉ、好マシくは２〜ｓ
ｔ／ｃｒｌの圧力にて瞬時に圧縮成形する。After rapid heating, the predetermined sM1 is preferably 200 to 40
1 to 5 t/ai, preferably 2 to s at a temperature of 0°C
Instant compression molding at a pressure of t/crl.

また、通常は圧縮成形する場合、外部よりピッチ等のバ
インダーを加えることが必要である力；、本発明におい
ては自己副生タールを７（インダーとする為、外部バイ
ンダーを必要としない。なお、一般に成形温度が高いほ
ど耐水性カニ向上する傾向７＞監ある。In addition, in the case of compression molding, it is normally necessary to apply a binder such as pitch from the outside; however, in the present invention, the self-by-produced tar is used as the binder, so no external binder is required. In general, there is a tendency that the higher the molding temperature, the better the water resistance.

続いて、高温圧縮成形された石炭の酸イヒ処理を行なう
。この操作は耐自然発火性を改善することを目的として
おり、通常は加熱下で行な贋、特に１００〜２００°Ｃ
の温度で行なうとすぐれた効果が得られる。酸化処理は
酸素濃度１容散％以上、通常は１〜２１容景％、好まし
くは４〜１０容斂％で５０分〜５時間、好ましくは２〜
３時間行なう。酸化処理は空気を用いて行なうこともで
きるが、望ましくは酸素と窒素を所定割合に混合した混
合ガスを使用する。Subsequently, the high-temperature compression molded coal is subjected to acid immersion treatment. This operation is aimed at improving spontaneous ignition resistance and is usually carried out under heating, especially at temperatures between 100 and 200°C.
An excellent effect can be obtained if the treatment is carried out at a temperature of . The oxidation treatment is carried out at an oxygen concentration of 1% by volume or more, usually 1 to 21% by volume, preferably 4 to 10% by volume, for 50 minutes to 5 hours, preferably 2 to 5 hours.
It will last for 3 hours. Although the oxidation treatment can be performed using air, it is preferable to use a mixed gas containing oxygen and nitrogen in a predetermined ratio.

上記酸化処理後、スチーム処理を行なう。スチーム処理
は８０〜１５０℃、好ましくは９０”この飽和湿度中で
２〜８時間行なう。なお、成形炭に対して酸化処理とス
チーム処理を同時に施しても差支えない。このスチーム
による表面処理によシ、成形炭の表面が疎水化され、成
形炭に耐水性をもたせることができる。After the above oxidation treatment, a steam treatment is performed. The steam treatment is carried out for 2 to 8 hours at a temperature of 80 to 150°C, preferably at a saturated humidity of 90°C.It should be noted that the oxidation treatment and the steam treatment may be applied to the briquette at the same time. The surface of the briquette charcoal is made hydrophobic, and the briquette charcoal can be made water resistant.

本発明の方法を適用した石炭は１００時間水中に浸漬し
た後の圧潰強度が１ｏｏｋｇ−ｒ／α以上と耐水性が高
く、雨ざらしになっても形がくずれず、しか−も水中浸
漬後の圧潰強度も高く、取扱いや貯蔵が容易である。し
かも本発明の方法を適用した石炭は含水率が著減してお
り、しかも原炭や豪州ブリケットと比較してすぐれた耐
自然発火性、耐発塵性を有しており、粉砕してもこの性
質を十分に維持し得る。また、上記の如く圧潰強度が大
きく、しかもかさ密度も通常１．１ｆｆ／ｄと大きいた
め、輸送効率もきわめて高いものである。さらに燃料と
して用いた場合、発熱量が高く燃料用脚として好適な性
状を有している。Coal to which the method of the present invention is applied has a crushing strength of 1ookg-r/α or more after being immersed in water for 100 hours, and has high water resistance, does not lose its shape even when exposed to the rain, and has a crushing strength after being immersed in water for 100 hours. It has high strength and is easy to handle and store. Moreover, the moisture content of coal produced using the method of the present invention is significantly reduced, and it has superior spontaneous combustion and dust generation resistance compared to raw coal and Australian briquettes, and even when crushed. This property can be sufficiently maintained. Further, as mentioned above, since the crushing strength is high and the bulk density is usually as high as 1.1 ff/d, the transport efficiency is also extremely high. Furthermore, when used as a fuel, it has a high calorific value, making it suitable as a fuel leg.

次に、本発明の実施例を示す。Next, examples of the present invention will be shown.

実施例１〜６ 豪州ヤルーン炭を３ｍ以下に粉砕し、窒素ガス雰囲気中
で１２０°Ｃで充分に乾燥した。その後、その乾燥炭（
性状を第１表に示す。）８ｆを内径２５咽φの金型中に
入れ、第２表に示す時間内に所定の成形温度まで急速加
熱し、次いでＳｔ／ａｄの圧縮圧で開時に成形を行なっ
た。しがる後、金型から取シ出し、酸素濃度６％の酸素
−窒素混合ガス中で１５０°Ｃの温度で３時間酸化処理
を行なった。酸化処理後、成形炭を９０”Ｃ飽和湿度中
でスチーム処理した。このスチーム処理は、ｉｏ。Examples 1 to 6 Australian Yalloon coal was pulverized into pieces of 3 m or less, and thoroughly dried at 120°C in a nitrogen gas atmosphere. Then, the dry charcoal (
Properties are shown in Table 1. ) 8f was placed in a mold with an inner diameter of 25 mm, rapidly heated to a predetermined molding temperature within the time shown in Table 2, and then molded at a compression pressure of St/ad when opened. After cooling, it was taken out from the mold and subjected to oxidation treatment at a temperature of 150° C. for 3 hours in an oxygen-nitrogen mixed gas with an oxygen concentration of 6%. After the oxidation treatment, the briquettes were steam treated at 90"C saturated humidity. This steam treatment was carried out at io.

℃の温浴でフラスコ内の蒸留水を９０’ＣＫ加熱し、フ
ラスコ中を水蒸気で飽和させ、この飽和水蒸気中に成形
炭を放置することによシ行なった。結果を第２表に示す
。なお、実施例２，５．５および６については水中に１
００時間浸漬して耐水性の評価を行なった。The distilled water in the flask was heated to 90° C. in a hot bath to saturate the flask with steam, and the charcoal briquettes were left in the saturated steam. The results are shown in Table 2. In addition, for Examples 2, 5.5 and 6, 1
The water resistance was evaluated after immersion for 00 hours.

比較例１〜６ 実施例１〜６において、酸化処理、スチーム処理のいず
れか一方もしくは両方の処理を行なわなかったこと以外
は実施例１〜６と同様に行なった。Comparative Examples 1 to 6 Examples 1 to 6 were carried out in the same manner as in Examples 1 to 6, except that one or both of the oxidation treatment and the steam treatment were not performed.

結果を第２表に示す。なお、比較例２，５．５および６
については水中に１００時間浸漬して耐水性の評価を行
なった。The results are shown in Table 2. In addition, Comparative Examples 2, 5.5 and 6
The water resistance was evaluated by immersing it in water for 100 hours.

第　１　表 ａ）工業分析としての乾燥炭の分析値（ドライベース）
灰　分　二　１．２重量％ 揮発分　：　５０．９重量％ 固定炭素　：　４７．９重量％ ｂ）元素分析　（ドライアッシュフリー）炭　素　：　
６４．０重量％ 水　素　：４．５重１１％ 窒　素　：１．ｏ重量％ 酸　素　：　５０．５重量％ 硫　黄　’　０−２ｆｉｊ１％ ・１　試料（円柱状成形物）をその直径方向から２０ｗ
／分の圧縮速度で圧縮したときの圧潰強度を厚みで除し
規格化した値である。Table 1 a) Analysis values of dry coal as industrial analysis (dry base)
Ash content: 1.2% by weight Volatile content: 50.9% by weight Fixed carbon: 47.9% by weight b) Elemental analysis (dry ash free) Carbon:
64.0% by weight Hydrogen: 4.5% by weight 11% Nitrogen: 1. owt% Oxygen: 50.5wt% Sulfur '0-2fij1% ・1 Sample (cylindrical molded product) was heated 20w from the diameter direction.
It is a value obtained by dividing the crushing strength by the thickness when compressed at a compression speed of /min.

なお、実施例２，５，５．６および比較例２．５，５．
６については水中浸漬後の圧潰強度を示したが、比較例
２，３および５については、成形炭の表面にひび割れが
生じ時間の経過と共に壌れてゆき圧潰強度の測定は不可
能であった。In addition, Examples 2, 5, 5.6 and Comparative Examples 2.5, 5.
For Comparative Examples 2, 3, and 5, the crushing strength after immersion in water was shown for No. 6, but the crushing strength of Comparative Examples 2, 3, and 5 was impossible to measure because the surface of the briquettes cracked and deteriorated over time. .

・３　実施例２，５，５．６および比較例２，３゜５．
６については水中に１００時間浸漬後の含水率を示した
。なお、成形炭の含水率は、水中浸漬後時間の経過と共
に増加するが、約７０〜１００時間でほぼ一定となるこ
とから、含水率の測定および圧潰強度の測定時の水中浸
漬時間は１００時間とした０Ｌ１４１％ＣＯ，発生温度
を示す。・3 Examples 2, 5, 5.6 and Comparative Examples 2, 3゜5.
Regarding No. 6, the water content after immersion in water for 100 hours is shown. The moisture content of briquette coal increases with time after immersion in water, but becomes almost constant after about 70 to 100 hours, so the immersion time in water when measuring moisture content and crushing strength was 100 hours. 0L141%CO, generation temperature is shown.

Claims (1)

【特許請求の範囲】 １、　石炭を実質的に含水率０％になるまで乾燥後、成
形温度まで急速加熱し、高圧下で圧縮成形し、得られた
成形物を酸化処理し、次いでスチーム処理することを特
徴とする石倹の改質方法０ ２　石炭が低品位炭である特許請求の範囲第１項記載の
改質方法。 五　石炭が褐炭である特許請求の範囲第１項記載の改質
方法。[Claims] 1. After drying the coal to a water content of substantially 0%, it is rapidly heated to the molding temperature, compression molded under high pressure, and the resulting molded product is oxidized and then steam treated. A reforming method according to claim 1, characterized in that the coal is low-rank coal. (v) The reforming method according to claim 1, wherein the coal is lignite.