CMA

28 • For optimal performance, AFRs should be fed to the cement kiln through appropriate feed points, in adequate proportions and with proper waste quality and emission control systems. • Due to the heterogeneity of waste, pre-processing is required to produce a relatively uniform waste stream for coprocessing in cement kilns. To be carried out in a purpose made facility, which may be located outside or inside the cement plant. The co-processing of hazardous substances in cement industry is much beneficial option, whereby hazardous wastes are not only destroyed at a higher temperature of around 14000 C and longer residence time but its inorganic content gets combined with the clinker apart from using the energy content of the wastes. Apart from this, no residues are left, which in case of incineration still requires to be land filled as incinerator ash. Further the acidic gases, if any generated during co-processing gets neutralized, since the raw material is alkaline in nature. Such phenomenon also reduces resource requirement such as coal and lime stone. Thus, utilization of Hazardous wastes for co-processing makes a win win situation. SUITABILITY OF SUBSTANCES FOR CO PROCESSING • High temperatures (Flame temperature >1800°C and material temperature up to 1400°C) • Long residence time • Oxidizing atmosphere • High thermal inertia • Alkaline environment • Ash retention in clinker POLICIES FORMULATED FOR SUSTAINABLE WASTE MANAGEMENT THROUGH CO PROCESSING • The waste management hierarchy needs to be respected. • Additional emissions and negative impacts on human health must be avoided. • The quality of the cement must remain unchanged • Companies that co process must be qualified with appropriate infrastructure.  Assure compliance with all laws and regulations.  Have good environmental and safety compliance records.  Have personnel, processes, and systems in place committed to protecting the environment, health, and safety.  Safe and sound receiving, storage, processing and feeding of hazardous wastes.  Systems for the provision and analysis of waste representative samples should be in place. Accept / Refuse Flowchart for a Cement Plant Operator Yes Yes Yes Yes AFR Accept Energy Recovery Material Recovery Energy & Material Recovery Waste disposal/ Waster destruction Accept Accept Accept Refuse No No No No GCV* gross calorific value Raw matirial ** CaO, SiO 2 , AI2O 3 , Fe 2 O 3 , SO 3 Uncontrolled burning Desirability Incineration Chemical-Physical Pre Treatment Co-Processing Recovery of Material (Recycle & Reuse) Minimization Land Filling Avoidance Elimination of waste Energetic and material use of waste Waste Management Hierarchy GCV* of total waste > 2500 Kcal/Kg and raw materials **=0% Ash>50% and raw material in ash>80% Raw Material **>0% and CGV* of the rest >2500 Kcal/Kg Resolution of local waste management problem?