DE2636232C2 - Process for converting non-coking coal into coke - Google Patents

Description

2. The method according to claim I. characterized in that a pitch is used, which consists of a secondary extract obtained by extraction of the primary extra gravel with propane

became.

3. Carbon paste produced by the method according to claim 1 and 2, characterized in that in combination they have a degree of swelling according to AFNOR NFM 11 001 between 7.5 and 9 between 15 and 50%, one according to the equation

c if-r DT,

certain G-factor between 055 and 1.10 and a baking ability between 10 and 17 kg for a mixture from 15 parts coal plus pitch per 1 part carbide and between 6 and 7 kg for a mixture of 20 parts coal plus pitch per 1 part of carbide.

H) The subject of the main patent P 23 38 928 is a process for converting non-coking coal into coke of blast furnace quality, using a paste of non-coking coal with 2 to 15% by weight of a pitch derived from petroleum with a softening point according to (he standard AFNOR Nf -T 66 008 of more than 100 "C of a penetration according to the AFNOR NFT 66 004 standard at 25 ' ¹ C by about 0 and a Conradson Index according to ASTM D-2416 of more than 40% by weight and the obtained (Jenlisch without any thermal

ti pretreatment is coked under known conditions.

From fuel chemistry J5 (1954) J / 4, ropes 44 it is also known to be a Kraekkyniponenie for To extract non-coking coals from oil residues by extraction with a solvent. These The publication deals with the coking of non-caking coals and makes reference to an Arbeil von Fischer, who is supposed to show that materials from the distillation: residues by extraction with benzene and cases with petroleum ether are said to have coking properties. What from this stand The skilled artisan cannot infer the technology without an inventive step, is the fact that Peche very special properties are suitable to improve the process of the main patent considerably.

According to the invention, a pitch obtained by blowing is used, which is obtained from a pitch by extraction an extract obtained by oxidative cracking using a vacuum distillate of crude oil with furfural

a mixture of an oxygen-containing gas with water vapor or an inert gas at a temperature of at least 340 ^° C. has been obtained.

A pitch obtained from a secondary extract is preferably used. obtained by extracting the primary extract with propane.
Oxydalivc cracking can be carried out using oxygen or air, expediently at normal pressure

be performed. Cracking combines the phenomena of oxidation, dehydration and Cracking.

When pitches made from the extracts are mixed with non-coking coal, Koksc are obtained which have the general properties mentioned in the main patent, but in addition have additional superior properties. One of the improved properties is mechanical

τ> strength, which is determined by the MICUM Stahlwcrk index (ISO / R 556 standard). With this method, the coke is subjected to an abrasion treatment in a rotating drum and its particle size is determined. The index M 40 is determined, i.e. H. the percentage residue of the coke on a sieve with a mesh Edge length of 40 mm. and the index M 10, i.e. H. the percentage of coke that passes through a sieve mil mesh one Edge length of I Omm happened. A blast furnace grade coke usually has an M 40 index greater than this

bo as 78 and an index M 10 under 8. The use of the extracts as starting materials enables the Achievement of an index M 10 of less than 8 and an index M 40 that is higher than that in the case of the

I luuptpnlcnics raise index over 81. f

The expandability of a coke of hole quality should also preferably be between 7.5 and 9. This | j

The value is determined with the help of the Ticgclmeihode according to AFNOR Nl-M Il 001. Using the %

w \ l'xirakie as starting materials can be a Bliihgrad be achieved in this area. %

Another property that affects the hole quality of a coke is the extent to which it expands dos materials choosing the coking The expansion defines the behavior of the Kokspaslc during the Success. The temperatures are measured (a) at the beginning of the softening (fusion), (b) the lower l'iincl and

(c) the end of softening. The shrinkage and final expansion in% are also measured (AFNOR standard NFM Il 004). It has been found that by using the extracts it is possible to achieve a final percentage expansion which is higher than in the case of the Kokspasicn described in the main application. Surprisingly, it was found here that the final percentage expansion of the coke according to the invention is between 15 and 50%. ^r >

Another indication of the quality of a coal paste is the G-factor. the liigonscliaficn the baking of the particles of the carbon core and, accordingly, the mechanical strength wedge of the final coke. This G'-factor was discussed by J. Gibson in his lecture "British Coals for Carbonization" before the 39. I Lochofcnkonferenz (Scarborough, 305.1971) reported. This G-factor or the capacity to form coke is used. mil I lilfc is determined by the following equation:

C + D

CT ₁₊ DT,
Is in here

T, the temperature at the beginning of softening,

Tr is the hardening temperature

C is the contraction in% and

D is the dilatation in%.

A furnace grade coal paste for coke preferably has a G-factor between 035 and 1.10. the Using the extracts as starting materials makes it possible to achieve this range.

Finally, it was found that the use of the extracts defines the baking ability of the charcoal paste according to a standardized test method of the hard coal industry, is increased. In this process, the Coke residue from coking a mixture of silicon carbide. Coal and bad luck arise, one subjected to increasing pressure until it breaks. The mixture tested can be 15 parts coal plus pitch per part carbide or 20 parts coal plus pitch per part carbide. With the coal pastes according to Invention, a coke residue is obtained, which is a pressure between 10 and 17 kp (with a starting mixture of 15: 1) or between 6 and 7 kp (with an initial mixture of 20: 1).

The starting materials used in the process according to the invention can be primary aromatic Be extracts obtained in the solvent extraction carried out using, for example, furfural or phenol from vacuum: ndestil'-jten of crude oil, or they can be secondary extracts. Secondary extracts are produced by further extraction of the extracts. In a preferred method the above-mentioned primary extract phase is cooled, whereby a phase separation is effected, at η on the one hand a secondary raffinate, which consists of a paraffinic and naphthenic hydrocarbon enriched fraction is formed and on the other hand a secondary extract in the l.ösungsmillelphase is precipitated. The solvent in the secondary extract is removed and the secondary extract with propane treated, which is a selective solvent for paraffinic and naphthenic hydrocarbons, wherein a softened secondary extract and an extract /. with a very high content of aromatic and polar 4 » Hydrocarbons and a kinematic tenacity (viscosity) at 98.9 "C, 1000cSl, especially below 500 cSt.

The primary extracts usually contain 50 to 70% aromatic and polar hydrocarbons. This content can be increased by up to 95% by re-extraction to form the secondary extract and, as already mentioned, a very high content is obtained by further treatment with propane. It should be noted that all types of extracts can be used in the process according to the invention, the propane-treated material called extract resin is particularly preferred.

The production of pitches by oxidative cracking is described in French patent specification 1230636. The process consists in blowing an extract or a secondary extract of the type mentioned above with oxygen or air at normal pressure at a temperature of 340 ^° C. or above and at the same time blowing in an inert gas or water vapor as the oxidizing gas. This treatment method has already been described in the main application. As mentioned therein, the process can be carried out batch-wise or continuously, for example in a column operating at normal pressure, which is provided with a device at the base, which draws air or water vapor together or separately. The hot gases emerging from the top of the column, which carry the volatile hydrocarbons formed by the reaction, are absorbed or condensed by any suitable absorption process or by cooling.

The proportion of the pitch can be 2 to 15%, preferably 5 to 10% of the coal pasle, based on the mixture, be. The mixture obtained is coked immediately under known conditions.

The invention is further illustrated by the following examples. bo

example 1

si A pitch was produced using a secondary extract as a raw material, which was obtained by extraction

"-" of a vacuum distillate of ZAKUM crude oil with furfural had been obtained and a kinematic viscosity b5

of 53.9cSt at 98.9 ° C (AFNOR standard NFT60 100), an aniline poiict of 15.5 ° C (AFNOR standard NFM 07 02l) and a viscosity / density constant iVGC) of 1.018 (ASTM D 2501/67).
The starting material was subjected to a continuous treatment which consisted of that with air

was blown at an elevated temperature with simultaneous blowing in of steam. That way three pitches were produced under the following conditions:

Bad luck 1

At a working temperature of 350 ⁰ C was treated with a quantity of air of 530 MVT use with water vapor was blown in an amount of 555 MVL, a pitch having a softening point of I68 "C.

in bad luck 2

In a Arbcitsicmperatur of 360 ⁰ C a pitch having a softening point of 180 ⁰ C and a penetration of 0 was treated with a quantity of air of 340 MVT Einsät / and with steam, the use in an amount of 315 m ^J / t was blown prepared.

Bad luck 3

^Be: a working temperature of 380 ° C with an airflow of 220 m ³ / t feed and water vapor, the m in an amount of 245 ³ / t insert was blown, a pitch having a softening point of 170 ⁰ C, a penetration of 0 and a Conradson Index of 41.9%.

Two batches of coal paste were made from these different pitches under Verv ·. separation of two various non-coking coals, namely

1. Batch A by adding a Lorraine coal (Freyming) which is believed to result in a poor quality coke and which has a degree of expansion of 5 to 6.5 and a G factor of 0.72 a pitch prepared in the manner described above in a proportion of 90% by weight of cabbage paste and 10% by weight of pitch:

2. a /. Meanwhile batch B by adding a German coal paste (Könijrsborn), which is also based on (iruiid Their low content of volatile constituents results in a loch-oven coke of worse (Jualiiiii, to

in an IVcIi prepared in the manner described above in a ratio of 90% by weight to kohienpasic

IOGcw .-% I Veh.

The Kohicnpasic obtained was coked in the laboratory.

For comparison, two batches were produced by admixing one according to Example 2 of the main patent Pechs made to the coal pastes in the above proportions.

The degree of expansion of the carbon pastes obtained from batch B is given in Table I below.

Table I.
Degree of bloating

Pitch 1 Pitch 2 Pitch 3 Example 2 of the main patent

7.5 8 8 6.5

The values in Table I / own that pitches produced by treating a furfural extract Have degrees of expansion that are significantly higher and cheaper for the use of the final coke for metallurgical Purposes are.

The results of tests to determine the Dilalalionsvurlaiifcs them are listed in Table H / IISAM ^r> <> mcngcsiclli.

Table Il

Ijgcnsehaflen "C Bad luck I. B. Pi ... Ί 2 B. Bad luck i B. example 2 ng Batch Batch Batch dcrSlumm- B. A. 382 A. 343 A. 342 anrnc ^! cii! 408 dal! the 432 473 470 A. 480 Onset of softening, ⁰ C 363 20th 358 20th 355 17th 380 22nd Recovery temperature, 430 15th 430 42 428 46 430 I. Koiilniklion. ° / o 15th asten i! ' 28 11 imliiii 25th Rear I. 20th • iillieh Dilation. % 14th 25th 28 - ^r ) The while in table II / a. Coals » emäl.1 of the I. ii 'den bek; Products dt

are surviving.

Dlt (λ Fa kl or. Determined by the equation already mentioned

2 CT ₁ + DT ₁

is listed in Table III below. Table III
G factor

Bad luck I bad luck 2

Charge Charge

ABA

Bad luck J B. Example 2 of the Charge; Slam registration A. Batch AWAY

i.010 0.985 0.995 1.06 1.005 1.078 0.90b 0.931

like UtiCKCiKici'i tigcnsOnuiicn uci is-omciipasic ciicspicCncii uessci ueii Dcuiiiguiigen. How much metallurgical grade coke is required in the coal pastes according to the invention. The comparison of the values of the baking ability of batches B. which contain the pitch 2, the pitch 3 and the pitch produced according to Example 2 of the main patent shows the improvement of the cabbage pastes by adding the extracts obtained by extraction of a vacuum distillate with furfural. The results of the comparative experiments are given in Table IV below.

Table IV

Baking maturity

Characteristic Pitch 2 Pitch 3 Example 2 of the main palm _{J ()}

15/1 kg 12.2 13.9 8.4

20/1 kg 5.9 6.4 4.5

A coal paste made from a mixture of 70% Freyming coal. 20% Koenigsborn coal. 5% bad luck 2 and 5% pitch 3 is coked in a large-scale plant, a coke with the following MICUM values are obtained: M! 0 = 7 and M 40 = 79.8.

For comparison, Freyming coal alone is coked under the same conditions, with the following MICUM results are obtained: M 10 = 10.5 and M 40 = 68.3.

Example 2

ΛΚ The starting material used for the production of the pitch was a resin prepared as follows: Hin secondary extract with a kinematic viscosity of 5.5 eSt at 98.9 "C was prepared by using a primary extra-phase containing furfural as solvent, the separation at 35" C was left. The 4 ^r> primary Extraktphasc was prepared by treating a Vakuumdcstillatfraktion from Kuwait crude oil with furfural. The secondary extract was treated with propane under the following conditions:

Dilution: 7.4 parts by volume of solvent per part by volume of extract

Temperature: 50 to 73 ° C

Pressure: 40 bar

The resin produced in this way had the following key figures:

Kinematic toughness at 985 ^C C: 87.5 Viscosity / density constant (VGC): 1.018

The resin was subjected to oxidative cracking, which was carried out continuously under the following conditions was carried out:

Average bubble Temperature: 380 ⁰ C

Injected air volume: 533 m ³ / t batch

Amount of nitrogen injected: 208 m ³ / t batch

The pitch received had the following key figures: <, -;

Reach point 160 ⁰ C

Conradson Indcx 485%

A charcoal paste of the type B described in Example 1 was prepared with the Extrakiharzpech and coked according to normal practice. The results obtained are shown in Table V below. For comparison are in this table the results of the coking of batch B of the pitch 3 containing .idcn cabbage paste of Example I in the laboratory and the results of coking a paste of Κ <κmgsborn-Kohlc alone 5 and, finally, the results of coking a coal paste similar to that in Example 2 of the main application contains pitch described, each included in the laboratory.

T .belle V

properties Mar / bad luck Bad luck J King's Bad luck for example 2 from example I. bornkohlc eic 1 liuiptn; ilt: nls Degree of bloating 8th 8th 7.5 6.5 Onset of softening. ° C 346 342 429 408 Reconsolidation temperature. "C 480 470 492 480 Contraction, "/ o 23 17th 22nd 22nd Dilation 52 46 - ·> 1 G factor 1.067 1,078 0.727 0.931 η — i-r ^ u: - i. ~ :.
l / uc i \ ι α 111g πι. ι τ 15/1 14.9 13.9 9.3 8.4 20/1 6.7 6.4 3 4.5

The results in Table V show that a significant improvement in the properties of the carbon fiber in the Comparison with the coal paste containing coal alone on the one hand and in comparison with that according to the method 25 of the main patent produced carbon pastes on the other hand is achieved.

JO / ■■;

Claims (1)

Patent claims: 1. Process for converting non-coking coal into blast furnace grade coke, being a paste a non-coking coal with 2 to 15% by weight of a pitch derived from petroleum with a softening point according to the AFNORNFT 66 008 standard of more than 100 ⁰ Q of a penetration according to the standard AFNOR NFT 66 004 at 25 ° C by about 0 and a Conradson Index according to ASTMC D-2416 of more than 40 wt .-% mixed and the resulting mixture under bckannicn without any thermal pretreatment Conditions is coked, according to Patent P 23 38 928, characterized in that a through Pitch obtained by blowing is used, which is obtained from a by extraction of a vacuum silicate from crude oil ίο extract obtained with furfural by oxidative cracking using a mixture of an acidic Substantial gas with water vapor or an inert gas at a temperature of at least 34 ° C has been echoed.