阅读说明：本技术 一种沥青球氧化不融化的前处理方法 (Pretreatment method for asphalt ball oxidation non-melting ) 是由 李开喜 于 2020-04-17 设计创作，主要内容包括：本发明公开了一种沥青球氧化不融化的前处理方法,是针对含萘或蒽的沥青球在进行氧化不融化之前的预处理提出的,直接采用气相的有机溶剂蒸气代替常规的液相萃取方法。具体是在含萘或蒽的沥青球中通入空气,以一定升温速率从室温升温到50-80℃停留2-20h,获得萘或蒽少量脱除的沥青球；之后切换为含有有机溶剂蒸气的惰性气体,并以一定升温速率升到脱除萘或蒽的温度,获得萘或蒽全部脱除的沥青球；最后,切换为空气,按常规的氧化不融化工艺获得相应的氧化沥青球。本发明不使用液相的有机溶剂,反应时间大幅缩短,处理范围广,成本极大减少,操作简便。(The invention discloses a pretreatment method for asphalt balls without melting after oxidation, which is provided for pretreatment before the asphalt balls containing naphthalene or anthracene are oxidized without melting, and the conventional liquid phase extraction method is directly replaced by vapor of a gas-phase organic solvent. Specifically, air is introduced into the asphalt ball containing naphthalene or anthracene, and the temperature is raised from room temperature to 50-80 ℃ at a certain heating rate and stays for 2-20h to obtain the asphalt ball with a small amount of naphthalene or anthracene removed; then switching to inert gas containing organic solvent steam, and raising the temperature to the temperature for removing naphthalene or anthracene at a certain heating rate to obtain the asphalt ball with all naphthalene or anthracene removed; and finally, switching to air, and obtaining the corresponding oxidized asphalt balls according to a conventional oxidation non-melting process. The method does not use a liquid-phase organic solvent, greatly shortens the reaction time, has wide treatment range, greatly reduces the cost and is simple and convenient to operate.)

1. A pretreatment method for asphalt ball oxidation without melting is characterized by comprising the following steps:

(1) a temperature rising stage: introducing air into each kilogram of naphthalene or anthracene-containing asphalt balls by 50-150 liters of air per hour, heating the asphalt balls from room temperature to 50-80 ℃ at the heating rate of 10-60 ℃/h, and staying for 2-20 hours to obtain the asphalt balls without a small amount of naphthalene or anthracene;

(2) naphthalene or anthracene removal stage: introducing corresponding gas according to the requirement that each kilogram of naphthalene or anthracene-containing asphalt balls needs 100 liters of mixed gas and 500 liters of mixed gas per hour, raising the temperature from the temperature in the step (1) to 90-120 ℃ at the temperature-raising rate of 5-60 ℃/h, and staying for 5-50h to obtain the asphalt balls with all naphthalene or anthracene removed;

(3) oxidation and non-melting stage: and (3) under the air atmosphere, introducing 1000 liters of air into each kilogram of asphalt balls per hour, raising the temperature from the temperature in the step (2) to 280-350 ℃ at the temperature raising rate of 240 ℃/h of 100-5 ℃, and staying for 0.5-5h to obtain the oxidized asphalt balls.

2. The pretreatment method for asphalt ball oxidation infusibility according to claim 1, characterized in that: the diameter of the asphalt ball is 0.05-2.0 mm.

3. The pretreatment method for asphalt ball oxidation infusibility according to claim 1, characterized in that: the mixed gas is as follows: organic solvent vapor and N₂Or Ar gas mixed according to a proportion.

4. The pretreatment method for asphalt ball oxidation infusibility according to claim 3, characterized in that: the organic solvent comprises any one of n-heptane, methanol and petroleum ether.

5. The pretreatment method for asphalt ball oxidation infusibility according to claim 3, characterized in that: the volume ratio of the mixed gas is as follows: organic solvent vapor: (N)₂Or Ar) in a volume ratio of (0.1-30) to 100.

Technical Field

The invention relates to a pretreatment method for asphalt ball oxidation without melting, in particular to a method for removing naphthalene or anthracene in asphalt through gas or steam.

Background

The asphalt-based spherical activated carbon belongs to high-performance activated carbon and has application in numerous fields. But oxidation during its preparation is not necessary to melt. According to research on the literature, the oxidation and non-melting treatment can be carried out only after the aromatic hydrocarbon mixture such as naphthalene or anthracene in the asphalt globule is extracted by an organic solvent before the oxidation and non-melting treatment is carried out.

U.S. Pat. No. 4, 4,228,037 "thermal activated carbon had low and high physical strength and Process for producing the same", U.S. Pat. No. 3, 4,273,675 "Process for the preparation of thermal carbon and thermal activated carbon composites", and U.S. Pat. No. 3, 4,371,454 "Process for the preparation of thermal carbon and thermal activated carbon composites", all three patents, with the exception that the aromatic hydrocarbon compounds containing naphthalene are removed from the asphalt pellets by organic solvents and then oxidized without melting.

Chinese patent CN97101618.6 "a method for preparing narrow particle size distribution asphalt balls" is to make asphalt and additive act together to make a eutectic, make asphalt balls containing additive by emulsification, and then remove additive to make porous asphalt balls. Chinese patent CN200610127621.1 "a method for preparing spherical activated carbon with low heavy metal content" also relates to the porous treatment of asphalt, and the method still adopts organic solvent to extract and remove naphthalene or anthracene and the like added during the modification of asphalt. Chinese patent CN97101617.8 "a method for preparing spherical activated carbon" specifically adopts a solvent extraction method to remove additives to prepare porous asphalt spheres, and then the porous asphalt spheres are subjected to infusible and carbon activation (carbonization and activation are completed synchronously) treatment to obtain the product.

At present, in the prior art, liquid-phase organic solvent such as n-heptane is adopted to soak and extract the asphalt globules containing naphthalene or anthracene in a special device so as to remove the naphthalene or anthracene in the asphalt globules, then solid-liquid separation is carried out, the asphalt globules without naphthalene or anthracene are obtained after drying, then oxidation non-melting treatment is carried out in the air, and therefore, the device for soaking and extracting, solid-liquid separation, drying, oxidation non-melting treatment and the like is involved, and in addition, a device for treating organic solvent mixture containing naphthalene or anthracene is also provided. In the prior art, the amount of the liquid organic solvent used is tens of times of the weight of the asphalt pellets, and more importantly, the organic solvent is flammable and explosive, so that the danger is great, and the production process is dangerous.

Disclosure of Invention

The invention aims to provide a pretreatment method for asphalt spheres without melting during oxidation, which does not need to use a liquid-phase organic solvent to extract naphthalene or anthracene in the asphalt spheres.

The principle of the invention is as follows: because the resulting asphalt pellets after pelletization contain modifiers such as naphthalene or anthracene, which are necessary for pelletization of the asphalt, but when the asphalt has been pelletized and further subjected to oxidation non-melting treatment, the presence of naphthalene or anthracene will significantly affect the conversion of the asphalt from thermoplastic to thermoset, and must be removed for this purpose. The invention changes the liquid phase organic solvent into vapor of gas phase, and the quantity used is very small, and no special device is needed, and the method can be directly carried out in the oxidation non-melting reactor. The principle of utilization is similar to liquid phase extraction (namely, the method that the organic solvent can be combined with naphthalene or anthracene in the asphalt globule to extract the naphthalene or anthracene therein is still utilized), and the principle that the diffusion performance of steam is obviously higher than the diffusion capacity of the liquid phase solvent is also utilized, so that the large particles of the naphthalene or anthracene in the asphalt globule are easily dissolved by the steam of the organic solvent, are converted into particles with smaller particle size and easy to volatilize, and the naphthalene or anthracene easy to volatilize per se is easier to escape due to the gradual rise of temperature. Given sufficient time and gradually increased temperature, naphthalene or anthracene can be extracted continuously by the vapor of the organic solvent and leaves the bulk of the asphalt globule until all naphthalene or anthracene is extracted completely, thereby completing the process similar to liquid phase extraction soaking. In addition, since the organic solvent and the vapor of naphthalene or anthracene that is volatilized out may reach the explosion limit after being mixed with oxygen in the air, inert gas is used to carry the organic vapor for this purpose, and the concentration of the organic solvent vapor can be controlled. The method and the thought used by the invention are brand new, and the obtained final result is also unexpected, so that the naphthalene or anthracene removal and oxidation non-melting reaction in one reactor are directly realized, and the series of problems and dangers caused by liquid-phase organic solvents are avoided.

The invention provides a pretreatment method for asphalt ball oxidation and non-melting, which comprises the following steps:

(1) a temperature rising stage: introducing air into each kilogram of naphthalene or anthracene-containing asphalt balls by 50-150 liters of air per hour, heating the asphalt balls from room temperature to 50-80 ℃ at the heating rate of 10-60 ℃/h, and staying for 2-20 hours to obtain the asphalt balls without a small amount of naphthalene or anthracene;

(2) naphthalene or anthracene removal stage: introducing corresponding gas into 500 liters of mixed gas (gas obtained by mixing organic solvent vapor and inert gas in proportion) required by each kilogram of naphthalene or anthracene-containing asphalt balls per hour, raising the temperature from the temperature in the step (1) to 90-120 ℃ at a temperature-raising rate of 5-60 ℃/h, and staying for 5-50h to obtain the asphalt balls with all naphthalene or anthracene removed;

(3) oxidation and non-melting stage: and (3) under the air atmosphere, introducing 1000 liters of air into each kilogram of asphalt balls per hour, raising the temperature from the temperature in the step (2) to 280-350 ℃ at the temperature raising rate of 240 ℃/h of 100-5 ℃, and staying for 0.5-5h to obtain the oxidized asphalt balls.

The diameter of the asphalt ball is 0.05-2.0 mm.

The mixed gas is the vapor of N-heptane, methanol, petroleum ether and N₂Or Ar gas mixed according to a proportion.

The ratio of the mixed gas is N-heptane or methanol or petroleum ether vapor to N₂Or the volume ratio of Ar is (0.1-30): 100.

Drawings

FIG. 1 is a graph of the oxidized infusible pellets obtained in example 1 in CO₂A pore structure for probe testing;

FIG. 2 is a graph of the oxidized infusible pellets obtained in example 2 in CO₂A pore structure for probe testing;

FIG. 3 is a graph of the oxidized infusible pellets obtained in example 3 in CO₂A pore structure for probe testing;

FIG. 4 is a graph of the oxidized infusible pellets obtained in example 4 treated with CO₂Is the pore structure of the probe test.

The oxidation non-melting degree of the asphalt balls in the embodiment can be calculated according to the bonding rate: putting the oxidized non-melting asphalt balls in N₂Heating to 800 ℃ in the atmosphere and then staying for 1h to obtain carbonized asphalt balls; and randomly extracting 30-50 carbonized asphalt balls, wherein the percentage of the total number of the particles adhered together to the total number of the particles is the bonding rate.