DE2911779A1 - Bitumen binders for prodn. of fuel agglomerates - comprising B 200 bitumen and precipitation bitumen - Google Patents

Abstract

Bituminous binders for prodn. of agglomerates from finely divided materials (esp. for briquetting solid fuels) comprise 53-60 wt% standard B200 bitumen (I) and 47-40 wt% of a precipitation bitument (II). The binders have a high Conradson C content (>=30%), can be used for briquetting without special control measures, and produce briquettes with high green strength and thermal stability. (II) pref has a softening point of 80-200 degrees C. The binders are produced by intensively mixing (I) and (II) at 150-200 degrees C. In use, the binders are sprayed onto the coal (etc) in an amt of 5-8(esp 6-7)wt%, after which briquetting is carried out in the normal manner. A mixt. of 53% B200 bitument (softening point 38 degrees C) and 47% pptn bitumen(softening point 163 degrees C) has a softening point of 95 degrees C, a penetration of 4.5, a Fraass breaking point of +13 degrees C, a Conradson C content of 35.5%, and an S content of 4.9 wt.%.

Description

"Use of still bottoms

from crude oil processing as a binder " For the Production of moldings, such as briquettes or pellets, from finely divided raw materials, As is known, it has proven useful to use binders as so-called briquetting aids to use. The binders used in the briquetting of coal should the moldings produced with their help have good transport and storage stability give and cause these moldings even at higher temperatures and below Pressure does not disintegrate or suffer other deformations. So far are for the generation of shaped coal bodies, such as briquettes or pellets, including coal tar pitch, Sulphite liquors, molasses and starch have been suggested as binders. The using Raw moldings made from sulphite waste liquor, molasses or starch are sensitive to water and must be subjected to additional operations to eliminate this disadvantage will. Coal tar pitch, on the other hand, throws in storage, handling and processing specific technical problems and calls frequently to the personnel involved Adverse health effects.

Conventional bitumen have not yet been used as a binding agent for the creation been used by carbon moldings, since with them only moldings are obtained that are characterized by insufficient furnace and fire resistance, according to the previous findings on the poor coking behavior of the -Bitumina is based. As a measure of this - compared to coal tar pitch - um The Conradson carbon value of the bitumens is considered to be 15 to 20% by weight lower. On the other hand, however, these bitumens are responsible for a binding agent that is used in the production of carbon molded bodies to be used, valuable properties that they the green moldings sufficient mechanical even without subsequent heat treatment Give strength, do not contain ash or slag forming substances and provide additional energy when the shaped bodies are burned. Also are Compared to coal tar pitch, the bitumina is easier to use handle, easier to store, transport and process. It is also essential that bitumens are physiologically not as questionable as coal tar pitch.

In a publication in petroleum and coal - natural gas - petrochemistry - Fuel chemistry "Vol. 26 (1973), pages 148 to 151, the use of a Social bitumen for the briquetting of coal is described, which in its physical, chemical and physiological properties closely based on conventional bitumina, but has a Conradson carbon value that is about 10% higher. A composition of special bitumen is not specified in this publication. Apparently counts a high vacuum bitumen to its components, which by additives in a higher Quality of the special bitumen for processing in the solid and in a softer one Quality for processing in the hot-liquid state has been transferred and has a Conradson Carbon value of 37 to 40% by weight. When using this special bitumen in amounts of 6.6 to 8.4 wt .-% for the production of hard coal briquettes, wherein the binder first on the coal to be briquetted with the help of steam is sprayed on and the resulting mixture to the usual process sequence, Intermediate bunker - kneader - press - cooling belt - bunker, is subjected, shows up, that the bituminous mixture is very sensitive to deviations from the usual Proceedings respond. Changes are particularly strong in this context of the water content of the starting materials, changes in temperature and pressure of the Kneading steam as well as the temperature of the briquetting material in the distributor head of the press noticeable. The use of these special bitumens therefore makes one special intensive monitoring of the briquetting process is necessary, which is associated with an increased, technical effort is connected.

From this arises the task of a bituminous binder with a Conradson-Garbon value 70n 30 and mR% by weight to look for, which during the incorporation into the briquetting goods require particularly intensive monitoring of the briquetting process makes it necessary to make briquettes shaped with it - even without additional heat treatment - gives a good green strength and a high thermal stability and without Ash or slag residue burns with little smoke.

It became a bitumen binder for the production of moldings found from finely divided substances, in particular finely divided fuels. Thereafter the binder should have a content of 53 to 60% by weight of the B 200 standard bitumen and 47 to 40% by weight of a precipitated bitumen.

The precipitated bitumen should advantageously have a softening point (Ring and ball) according to DIN 1995 from 80 to 200 ° C. Has particularly proven itself such a precipitated bitumen, which has a Fraass breaking point of + 250C.

The standard bitumen are used to produce the binder of the invention B 200 and the precipitated bitumen intimately mixed in the specified proportions. This measure is advantageous by heating the mixture to a temperature from 150 ° C to 200 ° C in an intensely acting mixer, such as in one Planetary mixer. The resulting mixture is pushing at the same The temperature is evenly sprayed onto the briquettes with constant circulation namely in amounts that the resulting mixture 5 to 8 Gewo, preferably 6 to 7% by weight, of the binder.

The mixture obtained is then in a manner known per se, for example on briquette rollers, pressed to form molded bodies.

Using the binder of the invention are among the Briquetting briquettes with excellent process conditions normally to be observed Preserved green strength and excellent heat resistance.

The examples given in Table I are used to carry out the examples Quantities of standard bitumen B 200 and of precipitated bitumen (softening point R + K 163 ° C; Fraass breaking point + 250C) at a temperature of 19000 by means of a planetary agitator Mix intensively for 15 minutes.

To determine the physical and combustion properties are made of this binder and briquetting charcoal on a stamp press prismatic Test specimens produced containing the amounts of binder indicated in Table II.

Table 1 Examples 1 and 2 test values according to DIN 1995 and analytical Data of the briquetting agents according to the invention and the mixing components B 200 precipitation Mixture Mixture bitumen I II 53.0 G.% B 200 60 G.% B 200 47.0 G.% precipitation 40 G.% precipitated bitumen bitumen softening point ring and ball ° C 38 163 95 87 penetration 1/10 mm 165 - 4.5 6.0 ductility cm 100 - - -Breaking point according to Fraaß ° C -15 +25 +13 +12 Conradson Carbon wt.% - - 33.5 34.0 Sulfur wt.% - - 4.9 4.7 Examples 3 and 4 (comparison) Instead of the binder of the invention, one is used for briquetting purposes customary special bitumen used in the amounts given in Table III and the physical and combustion values are determined, which are also specified in Table III are given.

Analytical data of the special bitumen softening point (R + K) 1030C Penetration 2500 0.3 mm ductility O cm Fraass break point + 15 ° C Conradson-Carbon-Vert 25% by weight sulfur 1.2% by weight Table II Briquetting Agent Mixture I Mixture II Briquetting charcoal wt.% 93 95 Binder wt.% 7 7 Test specimen (50x50x20 mm) breaking strength kp / cm2 32.7 29.3 sulfur coke (600 ° C) breaking strength kp / cm2 14.6 14.2 nut briquettes mass g 24.5 24.5 point compressive strength - at 20 ° C kp 103.7 105.2 - at 20 ° C, wet "96.5 95.5 - at 40 ° C" 68.5 69.5 - at 60 ° C "43.0 51.0 Sulfur coke point compressive strength kp 57 63.5 Drop test, 500 ° C 30 min abrasion% 4.9 4.2 Burning behavior Soot tar number 241 183 Solid immissions test, cold trap method g / 7500 Kcal 21.2 22.6 Table III Briquetting agents special bitumen Special bitumen Briquetting coal wt.% 92 95 Binder wt.% 8 5 Test specimens (50x50x20 mm) breaking strength kp / cm2 36.1 21.0 sulfur coke (600 ° C) breaking strength kp / cm2 25.0 18.0 nut briquettes mass g 23.5 23.5 point compressive strength - at 20 ° C kp 112.7 65.5 - at 20 ° C, wet kp - - at 40 ° C kp 63.5 43.0 - at 60 ° C kp 54.5 35.5 sulfur coke point compressive strength Drop test, 500 ° C kp 100.0 56.5 30 min abrasion% 2.1 5.6 Burning behavior Soot tar number - -solid immissions test, cold trap strongsg method g / 7500 Kcal smoke development Well

Claims (2)

Claims binders made of bitumen for the production of shaped bodies made of finely divided substances, in particular finely divided fuels, characterized due to a content of 53 to 60% by weight of the standard bitumen B 200 and 47 to 40% by weight of a precipitated bitumen. 2. Binder according to claim 1, characterized in that the precipitated bitumen has a softening point (ring and ball) according to DIN 1995 of 80 to 2000C.