Recycling Of Cold Rolling Waste Oil

At present,the cold rolling emulsion is most widely used as metal cutting fluid in China's machinery industry.It mainly consists of rolling oil,water,emulsifier,antioxidant and oily agent.After repeated use,the emulsion will be mixed with dust,metal debris and other impurities.Meanwhile the growth of bacteria lends to corruption and aging.They all reduce the lubrication,protection and other performance of the emulsion,resulting in a waste of cold rolling oil.In view of the waste emulsion produced during cold rolling process,this paper researches the most effective recovery process,analyzes the reasons and characteristics of emulsion and the mechanism of demulsification.The research compares the effects and the factors that various types of demulsifier take on the experimental samples,analyzes the optimal conditions of electrolytic demulsification.Using the centrifugal force strengthens the effect that demulsifier takes on the waste emulsion.Afterwards comparing the effects of several kinds of demulsification methods through factors like dehydration rate,removal of mechanical impurity.The experimental result indicated that the waste emulsion is W/O emulsion,whose moisture content are 68.75% and the mechanical impurity content is 4.2%.Each index effect on the dehydration rate in the order : time > dosage of demulsifier > temperature >pH > salt content.The oil-soluble demulsifier condenses water droplets in the emulsion faster and more efficiently than the water-soluble demulsifier.The optimal chemical demulsification conditions of waste emulsion are temperature 55?,demulsifier 10mL/L dosage(The dosing ratio of PE-2157 A and N-4121 is 1:3),time 30 minutes,and the dehydration rate can reach more than 94.4%,the mechanical impurity content reduces to1.2%.The dehydration rate of electrolytic demulsification increases with the reaction time.The results show that demulsification efficiency is optimal when the voltage is 10 V,the plate spacing is 1cm,the concentration of NACl is 0.75 g/L,the reaction time is 1 hour.Under those conditions,the dehydration rate can reach 89.8%,the mechanical impurity content reduces to 2%.The centrifugal effect can be used to break the emulsion rapidly,but the dehydration rate when used alone is only 42%..In speed 3500 r/min,centrifugal time 5minutes,temperature 55 ?,demulsifier dosage 10 mL/L conditions,dehydration rate can reach 94.9%.The centrifugal effect not only improves the demulsification effect of demulsifier,but also shortens the demulsification time significantly.Through the comprehensive analysis of dehydration rate,removal effect of mechanical impurities,time and so on,the final recovery process of cold rolling waste emulsion is using sedimentation centrifuge in speed 3500 r/min,centrifugal time 5 minutes,temperature 55 ?,demulsifier dosage 10 mL/L conditions.The moisture content of the recovered oil is trace,which meets the requirements of the oil products.Filtration is the final process of regeneration of waste emulsion,and also the key link to the remove gum and residual impurities in oil.The plate and frame filter press is used in the industry to further purify the oil and meet the requirements of the product.The plate and frame filter press using multifil filter cloth as a mediumis usually used in the industry to further purify the oil and meet the requirements of the product.