Strategy Waste Flow for Urban Mining from Household Waste of Thailand

The growth in Thai industry leads to the substantial demand on raw materials, especially precious metals. However, it seems to be difficult to operate new mines in Thailand due to the depletion of these natural resources and the environmental concerns from mining. Thai government has realized this problem; therefore, “urban mining” concept has been promoted with the purpose of reducing the utilization of natural resources by recycling raw materials from waste for sustainable development of Thai industry. Prior to implementation of urban mining concept, the feasibility study of current Waste Flow has to be conducted in order to set up Strategic Waste Flow and formulate the policy for material recovery. This study will focus on the current waste flow analysis of used electrical household appliances which include used computer, used air conditioner and used mobile phone due to their high precious metal content, e.g. Au, Ag, Co, Cr, Cu, Pb, Pd, Pt, etc. The average amount of selected household appliances discarded during 2008-2012 is estimated to be 45,329 ton annually and the increasing rate varies from 11% to 27 % each year depending on type of household appliance. The management methods of these appliances are mostly home storage (more than 50 %). The remaining are sold to recycling shops or manufacturers (15-40 %) and reused as second hand appliances (about 15 %). From the survey of current waste flow, it is found that precious metal recovery from electrical household appliances in Thailand is prohibited due to the lack of systematic and efficient collection system. Hence, prior to implementation of urban mining concept, this problem should be solved. The systematic and efficient collection system can be achieved by set up the obligation for manufacturers or designated cooperation to collect the used household appliances and transport them to the recycle plant of local governments or manufacturer. Fig. 1 illustrates the current waste flow and suggested strategic waste flow of household appliances for Thailand.