摘要:
In a continuous method for production of a semicoke powder with high bulk density and flowability, a sinterable carbon powder (semicoke) is dispersed in water with addition of at least one binder and at least one liquefier, wherein the proportion of carbon in the dispersion is adjusted to at least 50 wt. %, relative to the mass of the dispersion, and the zeta potential of the dispersion is adjusted to less than −50 mV, the dispersion is submitted to homogenisation and stabilisation by continuous wet grinding with a residence time in the mill of less than 3 minutes and the homogeneous dispersion is spray-dried.
摘要:
An isotropic coal tar pitch having a low content of carcinogenic compounds is prepared by distilling a coal tar pitch in an evaporator having a specific evaporator surface of from 330 to 10,000 m.sup.2 /m.sup.3, at a temperature in the range of from 300.degree. to 380.degree. C., under a pressure not exceeding 1 mbar, whereby the average stay period is from 2 to 10 minutes. The isotropic pitch thus obtained contains less that 50 ppm of benzo[a]pyrene and is suitable, optionally after adding an oil, resin or other modifying agents having a low benzo[a]pyrene content, for use as binding and impregnating agent and also as protecting agent in construction materials or as varnish (painting agent).
摘要翻译:具有低含量致癌化合物的各向同性煤焦油沥青通过在具有330至10,000m 2 / m 3的特定蒸发器表面的蒸发器中蒸馏煤焦油沥青而制备,温度范围为300-380℃ C.在不超过1毫巴的压力下,平均逗留时间为2至10分钟。 由此获得的各向同性沥青包含少于50ppm的苯并[a]芘,并且任选地在加入具有低苯并[a]芘含量的油,树脂或其它改性剂之后,适合用作结合和浸渍剂,并且还 作为建筑材料中的保护剂或清漆(涂漆剂)。
摘要:
The invention relates to a method for manufacturing carbon-bonded refractory products from refractory granulations and organic binder agents, wherein a powdery, graphitable coal-tar pitch with a benzo [a]pyrene content less than 500 mg/kg and a coking value of at least about 80% by weight according to DIN 51905 and a graphitable binder agent liquid at room temperature, with a coking value of at least about 15% by weight and a benzo[a]pyrene content less than 500 ppm according to DIN 51905, are used as organic binder agent, mixed with the remaining constituents, transferred to a mould body, then heat treated at a temperature of 150 to about 400° C.
摘要:
Contrary to known alkylation of pitches, it is disclosed that pitches are modified with particular aromatically substituted and activated C.sub.1 to C.sub.4 alkyl groups. The resulting modified pitches are easily polycondensed and give high coking residues and good mesophase formation. This is achieved on the one hand by dispensing with catalysts, which can be only incompletely removed from the pitch and, on the other hand, by employing reactive short chain alkyl aromatic compounds.
摘要:
In a continuous method for production of a semicoke powder with high bulk density and flowability, a sinterable carbon powder (semicoke) is dispersed in water with addition of at least one binder and at least one liquefier, wherein the proportion of carbon in the dispersion is adjusted to at least 50 wt. %, relative to the mass of the dispersion, and the zeta potential of the dispersion is adjusted to less than −50 mV, the dispersion is submitted to homogenization and stabilization by continuous wet grinding with a residence time in the mill of less than 3 minutes and the homogeneous dispersion is spray-dried.
摘要:
A carbon powder is disclosed with 40 to 75% by weight QI or more than 90% by weight TI, an optical anisotropy of less than 50% by volume, a start of softening between 200.degree. and 300.degree. C., and an oxygen content of more than 2% by weight, and which can be used for without binding agent the production of shaped carbon bodies. The carbon powder is produced by means of distillation from bituminous product at a maximum of 5 mbars and a final temperature of at least 400.degree. C., grinding of the distillation residue to a particle size of less than 30 .mu.m, and oxidation of the powder into the particle core.