| 摘要 |
PURPOSE:To obtain the titled pitch by efficiently removing quinoline-insolubles, by mixing coal tar or pitch with specified solvents and allowing solvent-insolubles to settle by gravity while keeping the mixture at a specified temp. under a specified pressure. CONSTITUTION:Coal tar or pitch is mixed with an arom. solvent having a b.p. of 180 deg.C or below (e.g. benzene or toluene) or its mixture (i), gas oil (ii) mainly composed of benzene and toluene or gas oil (iii) mainly composed of components having a b.p. of 250 deg.C or below. While keeping the mixture at 150 deg.C or above under a pressure of 5atm or above, solvent-insolubles are allowed to rapidly settle by gravity, whereby QI-free pitch having a controlled beta resin content can be obtd. The separation of the solvent-insolubles can be made by filtration, centrifugal separation, precipitation by gravity, etc. In this process, they can be efficiently separated by precipitation by gravity, since the precipitation rate can be increased by reducing the density and the viscosity of liquid by keeping the separation zone at a high temp. |
