Research On Technologies Of Separation Of Light Material From Construction Waste

The effective separation of light materials in construction waste is a key technical for the recovery of construction waste and improvement of the quality of construction aggregate recycling.As the mixed of light and heavy materials in the construction waste,which makes it difficult to effectively separate.In this paper,Based on the winnowing technology,the loose and separated scheme were proposed.Basis on this,a corresponding winnowing separation system,which consisted of the loose system and the negative pressure adsorption separation system,was designed and studied.This new technology belongs to the dry separation technology.Also,compared with the manual sorting and water selection methods,it is more efficient,non-polluting and has more application prospects.The main research contents are showed as the following aspects:1.The research of the Loose System: According to the characteristics of the material particles,a loose-efficiency index that meets the loose working conditions was defined to study the loose layering of materials.In order to study the Influence law of the loose trajectories and loose parameters on loosening efficiency,a EDEM simulation model was constructed by using the particle flow discrete element collision analysis method.And,The optimum process parameters which compatible with the characteristics of loose materials was determined.Basis on this,the corresponding loose prototype was designed to verified the rationality of the loose system2.The research of the negative pressure adsorption separation system: The structure of the negative pressure adsorption system was designed,and a suitable flow field structure of the negative pressure adsorption separation system was determined by using the fluid simulation technology.Based on this,a prototype of the negative pressure adsorption separation system was designed,and the air flow field test was carried out to verify the effectiveness of the negative pressure adsorption separation system.At the same time,the winnowing separation test of the light substance was carried out,which combining with the prototype of the loose system and the prototype of the negative pressure adsorption separation system,to study the separation effect of light and heavy materials in the wind separation system by using the optimal process parameters.the experimental results showed that: The structure of the winnowing separation system is reasonable,and it could achieves the effective separation of the light substance from the construction waste.The winnowing separation technology of the light material which used in this paper belongs to the common technology in the field of resource recovery.However,it is not only suitable for the separation of light and heavy materials in construction waste,but also can be expanded into the other resource recovery fields such as the domestic waste,mineral waste,agriculture.In addition,it also has a certain reference significance for the design of related wind-selected equipment.