Solidification / Stabilization (S/S) is a revisited technology that gives a new dimension in treatment and reuse of hazardous waste. S/S technology has been used to immobilize heavy metals, as well as, soils and sludge contaminated with heavy metals. The technology provides several advantages including waste handling and final disposal of the solid matrix. This book covers niche area within S/S technology to explore the S/S process of incineration ash from several types of incinerators. Discussion on ash samples from clinical waste incinerator, mixed hazardous waste incinerator, bottom ash of a municipal solid waste incinerator and ash from coal fired power plant is included. This book explores in detail the vast amount of published work in S/S and it's relevance in treating incineration ash. Unlike sludge, incineration ash contains extremely high level of heavy metals which need to be contained for safe disposal with minimal environmental impact. This book describes all options available for such disposal. The contents would be extremely useful to industrialists, waste managers, researchers and postgraduate students.