US3878052A

US3878052A - Method of producing metallurgical coke

Info

Publication number: US3878052A
Application number: US141394A
Authority: US
Inventors: Yasuo Hayashi; Mitsutoshi Miura
Original assignee: Nippon Kokan Ltd
Current assignee: JFE Engineering Corp
Priority date: 1970-05-11
Filing date: 1971-05-07
Publication date: 1975-04-15
Anticipated expiration: 1992-04-15
Also published as: DE2123313B2; GB1343691A; DE2123313A1; DE2123313C3; IT942099B; JPS491921B1; FR2091462A5

Abstract

A method of producing strong coke in that the physical properties, particularly its strength is improved, by which a metallic or a non-metallic wire like material is added to and mixed with general coking coal or blended coal. It is recommended that such wire like or small piece material is selected within the range of 0.1 to 0.8 min. diameter or width 2 to 150 mm length and then is added to said coal within the amount of 0.01 to 0.5% by weight.

Description

United States Patent Hayashi et al.

METHOD OF PRODUCING METALLURGICAL COKE Inventors: Yasuo Hayashi; Mitsutoshi Miura,

both of Yokohama, Japan Nippon Kokan Kabushiki Kaisha, Chiyeda, Tokyo, Japan Filed: May 7, 1971 Appl. No.: 141,394

Assignee:

Foreign Application Priority Data May 11, 1970 Japan 45-39247 U.S. Cl 201/20; 201/21 Int. Cl C10b 57/06 Field of Search 201/20-24,

References Cited UNITED STATES PATENTS 6/1883 Pittinos 201/24 1451 Apr. 15, 1975 2,808,370 10/1957 Bowers 201/22 2,824,047 2/1958 GOrin et al.... 201/20 2,919,231 12/1959 Donath 201/20 X 3,536,589 10/1970 Voet et al 201/20 X Primary ExaminerA. Louis Monacell Assistant Examiner-David Edwards Attorney, Agent, or FirmUlle C. Linton [57] ABSTRACT 3 Claims, No Drawings METHOD OF PRODUCING METALLURGICAL COKE This invention relates to a method of producing metallurgical coke, and is more particularly directed to an improved method for producing strong coke of excellent strength even in the case of coking coals.

The strength of coke is one of the important properties required in metallurgical coke employed in iron making fields and the like. For this reason, many plans as how it may be improved have been proposed and put into practice. It is, for example, well known that medium hard pitch which approximate to chemical quality of the coking coal, anthracite, oil coke which is useful as an aggregate or ferro-coke which is produced by mixing the calcined iron ore with a coking coal, is added to the coking coal or blended coal.

it is, however, also well known that the above prior arts have unfavorable disadvantages as follows:

1. In the case of the adding of pitch, the addition of said pitches may be suitable as a promoting agent for fluidity of the coal when the rate of operation of the oven is low and the carbonization temperature is less than 1200C. However when said temperature is more than l200C, it deposites carbon on the wall of the oven whereupon the thermodecomposition in said oven becomes violent and may interfere with the exhausting of gases and the pushing operations of said oven. This fact increases a tendency to the generation of bubbles in said coke and consequently may bring about the lowering of its strength.

2. in the case of the adding of inactive materials, the addition of inactive materials such as anthracite, the similar coal, powder coke, oil coke, mineral material or the like is useful to a coal having caking power and with fluidity as the existance of a nucleus, consequently may be used for the improving of said strength. However, when such coal whose fluidity is low as a Canadaproduced coal or an Australia-produced coal is blended with other coals the addition of the above inactive materials should be limited because the addition interferes with the caking power.

Thus, it will be obvious that the above prior methods are not always effective.

This invention has been developed to remove the above disadvantages. The features of this invention lie in the improving of coke properties by means of adding a wire like or a small piece of metallic or non-metallic material to coking coals or blended coals. It is needless to say that such a method is essentially different from said prior art.

Thus, an object of this invention is to provide a method of improving the strength of coke produced with coking coals or blended coals.

This present method can promote a caking power peculiar to the blended coals with ease.

Another object of this invention is to provide a method of reinforcing the coking of blended coals at the stage of said carbonization and of being possible to prevent the crush of said coke, which is apt to occur at the removing, storing and charging stages.'

Other objects and advantages will be apparent from the following description.

In this invention, wire like or small pieces of metallic materials including steel, stainless steel, copper and the like and carbon fiber, carbon rich synthetic resin and the like aswire like or small piece of non-metallic materials. With such materials, the velocity of heat transfer which is flowing from the wall to center portion of the oven increases and the heat transfer is possible to be promoted. The remarkable effects based on such a heat transfer are as follows;

First, the above materials do duty for linking up cracks of coke which are apt to occur at the stage of said carbonization. Secondly, the coking is promoted with said heat transfer because said material supplied heat to nearly coals. Thirdly, the tightening of said coke is strengthened. while the carbonizing velocity is stepped up, it may be expected that the graphiting is advanced by the equalizing of thermal distribution.

According to many experiments, it is confirmed that when the shaping of the above wire like or small piece of materials is selected within a certain range and said materials are added within a certain amount, the above mentioned effects reach the maximum. That is, the diameter of said material is selected within the range of from 0.1 mm to 0.8 mm and the length, within the range of 2 mm to mm. Such materials should be added within the amount of from 0.01% to 0.5% by weight, preferably 0.03% to 0.3% by weight.

It is not always required that the section of said wire like materials is circular. If the dimensions are within the abovementioned range, a small piece which is cut from sheet materials as steel sheet may be also employed. Accordingly, it is needless to say that wire rod or turning scrap is also suitable materials as the wire like materials of this invention.

The reasons that the dimensions of said adding materials are so limited as mentioned above, are as follows; that is, when said material is too small, it tends to be melted in an elevated temperature, e.g. more than l300C and when said material is too big, it gives a bad influence to its combinability for said blended coals. The limit of the length is based on the similar reasons. When it is too short, said material tends to be melted and when it is too long the grain size of said coke will become difficult to be controlled. When the added amount of said materials is less than 0.01% by weight, said combination effects are lessened andsaid. heat transfer effects are also lowered. Conversely, even though the amount is too much, there is little trouble. However, said added amount should be limited to a certain value on the basis of its economical consideration. For example, when the produced amount of coke reaches 250,000'lmonth, said wire like material of 2,500t/month will be required by adding rate of 1% by weight. Even though said material is steel wire which is possible to be obtained with ease, it is not easy to prepare such a great deal of said wire rod. This is a reason that said adding amount is limited to less than 0.5% by weight.

The coke properties according to this present method are excellent as shown in the following examples. That is, the strength of about 1.0% by drum index and of about 6% by shatter index 50 m/m is possible to be obtained with ease.

The actual examples according to this invention are as follows.

Blended Brand Beatrice Low volatile coals produced in U.S.A. Tams Davis. B Medium volatile coals produced in U.S.A. Eagle. S

-Cont1nued TABLE [V Medium volatile Vicary coals produced in Canada R. Moure Medium volatile Drum Test coals produced in Australia lltnfl Kind: ISm/m -25m/m 50m/m O11 coke Basic coals 88.8% 81.6% 20.4% m -p p Added Coals 90.0% 82.6% 20.7% Addms 111w muwfluls Difference +12% +1 .0 /1 +0.17. diameter: 0.6 mm length: 60 mm adding amount: 0.17% by weiglgtl I n d I" Blendin rate: as shown in Ta e an Carboni zation temperature: 1100C TABLE V Basie coals: usually blended coals. no who like materials.

Shatter Test Kind 75m/m SOm/m 38m/m 25m/m l5m/m TABLE I Basic Goals 13.3% 57.5% 81.0% 94.2% 97.1%

Added Blended Di Added Basic Difference Coals 19.9% 65.5% 82.9% 94.4% 97.0%

Brand Coal Coal Difference +63% +80% +1 .9% +0.12% -0. 1% Beatrice 7 l5 m/m 90.1 89.2 +0.9

Tams 7 m/m 82.7 82.4 +0.3 Note: "Added coalsis the blended coals that w l" m' Davis. 8 27 m/m 15.9 15.5 +0.4 20 basic coals. Eagle. 5 10 ST Z Vicarv 7 75 m/m 16.9 9.3 +7.6 Mud. I4 50 Wm 565 +93 The mean particle size from the above-mentioned Oil Coke 5 38 m/m 82.4 78.4 +4.0 Shatter test is as follows Higher grade 1 home- 16 25 m/m 94.- 93.9 +0.3 Basic coals: 545% qrftduccd 25 Added Coals: 57.9% coal Difference: 3.4% Lower grade q 9 7 9 9 7 1 mm 7 6 w The above mentioned Tables show results by test coke oven. According to the Tables, it will be under- TABLE 11 Added Coal Added Coal Difference Difference Blended Bran D1 "/1 (Fe) (Cu) Basic Coal (Fe) (C Beatrice 7 15 m/m 89.4 90.4 89.0 +0.4 +1 ,4 Tums 7 25 m/m 82.6 84.3 81.9 +0.7 +2.4 Davis. B 26 50 m/m 19.1 16.0 15.3 +3.9 +0.7 Eagle. S 8 St 71 Vicary 10 m/m 15.1 13.3 15.7 0.6 2.4 R. Moure 14 50 m/rn 62.3 61.0 60.7 +1.8 +0.3 Oil coke 3 38 m/m 82.7 83.6 82.8 0.1 +0.8 ltman 7 25 m/m 94.4 94.2 94.1 +0.3 +0.1 Higher grade home-produced 18 15 m/m 96.8 97.3 96.0 +0.8 +1.3 coal TABLE III l [2] Pitch Pitch l [2] Pitch Pitch Blended Added Added 3% 6% Basic Differ- Differ- 3% 6% Brand '7: D1% Coal Coal Added Added Coal ence( Fe) ence( Fe) Diffe r- Differ- (Fe) (Fe) Coal Coal ence ence Beatrice 7 l5 m/m 89.8 90.7 90.6 91.3 88.3 +1.5 +2.4 +2.3 +2.0 Tams 7 25 m/m 82.5 82.6 81.4 84.4 80.4 +1.1 +2.2 +1.0 +4.0 Davis.B 26 50 m/m 25.2 22.5 13.0 15.4 20.3 +4.9 +2 2 -7.3 5.1 Eagle.S 8 ST 3 Vicary 10 75 m/m 26.6 20.5 16.0 14.0 17.4 +9.2 1 4 -2 R.Moure 14 50 m/m 70.8 67.6 59.0 60.0 56.0 +4.8 +3.2 +4.0 Oil coke 5 38 m/m 84.6 85.2 81.8 83.5 81.1 +3.5 +(),7 +24 Hi 'her grzi de 14 25 m/m 94.3 94.7 94.5 95.2 94.4 +1.0 +0.1 +0.8 homeproduced coal Lower grade home- 15 m/m 96.8 97.0 97.4 97.3 97.0 0.2 +0.4 +0.3 produced coal The mean values of drum test and shutter test are as follows in Table IV and V.

stood that the results of added coal by this invention method are superior to that of basic coa1..Specia1ly, the

fact that the mean particle size of the added coat is superior to that of the basic coal by about 3% shows the decreasing of said crush of coke. It is, in general, well known that the results by test oven are displayed at lower rate than that of actual coke oven. Because, the carbonization velocity of said test coke oven is sooner than that of said actual coke oven. Accordingly, it will be needless to say that the effects of adding wire like materials performed by the actual oven is higher than that of the above test oven.

Further, observing the appearance of said coke. there was no bad influence in spite of the addition of said wire like materials. That is, the tendency of segregation is not recognized and the forming of known small hole is not obstructed. The surface quality of said coke is also very good. Thus the appearance quality of said coke as well as that of the prior coke.

We claim:

1. In a carbonization of coal in a coke oven, a method of producing metallurgical coke characterized by equally distributing and mixing a wire-like material to and with coking coals which is charged into said oven, wherein the width of said wire-like material is within the range of 0.1 to 0.8mm, and length of said material is within the range of 2 to l50mm, and the adding amount of said material is within the range of 0.01 to 0.5% by weight.

2. A method of producing metallurgical coke as set forth in claim 1 wherein an adding and mixing material is from the group of steel, stainless steel or Cu.

3. A method of producing metallurgical coke as set forth in claim 1 wherein an adding and mixing material is fiber carbon or carbon rich synthetic resin.

Claims

1. IN A CARBONIZATION OF COAL IN A COKE OVEN, A METHOD OF PRODUCING METALLURGICAL COKE CHARACTERIZED BY EQUALLY DISTRIBUTING AND MIXING A WIRE-LIKE MATERIAL TO AND WITH COKING COALS WHICH IS CHARGED INTO SAID OVEN, WHEREIN THE WIDTH OF SAID WIRE-LIKE MATERIAL IS WITHIN THE RANGE OF 0.1 TO 0.8MM, AND LENGTH OF SAID MATERIAL IS WITHIN THE RANGE OF 2 TO 150MM, AND THE ADDING AMOUNT OF SAID MATERIAL IS WITHIN THE RANGE OF 0.01 TO 0.5% BY WEIGHT.