... Definition: Wash oil is an important process of coal tar distillation fractions, one of about 6.5-10% coal tar ... biphenyl, methyl naphthalene, acenaphthene, fluorene, dibenzofurans and other products of raw materials, used to absorb benzene.In addition, for ... the preparation of anti-corrosion oil, production of quinoline, indole, dispersants, water reducing agent. ...