The Theory And Application Of Wheel Type Clay (mixed) Used Sand Reclamation

China is one of the largest producer of castings in the world. And tens of millions of tons of used sand emissions, caused by tremendous pressure on the environment. Especially in recent years, with the organic binder of the widely used, so that a large number of resin core sand mixed in the used clay sand, and take shape the clay (mixed) used sand. Therefore, these mixed used Sand reclamation, in place of new sand core making a new topic. As a result of a huge difference with the contain of clay and LOI between the mixed used sand and the core sand, the general method can not meet the requirements of regeneration. Renewable wheel can provide a powerful force, an effective get out the old sand the surface of inert membrane, it has become mixed Sand reclamation, one of the most effective way.In this paper, the domestic situation of mixed used sand were investigated. Renewable for further grinding wheel provide the basic data of the study. Research on the bonded film's morphology and composition of used clay-bonded (mixed) sand,which adopted stereo microscope SEM and EDS combined analytical method.It is founded that the most of the bonded film's composition of used clay-bonded (mixed) sand is distinctly different to mono used resin bonded sand and mono used clay sand,which the substrate is used resin bonded sand and its surface mulched clay-bonded film.Experimental study on renewable dressing several important parameters of the regeneration:Wheel speed, wheel and the distance between the sand barrels and the effect of regeneration time on the impact of regeneration. Studied at the same time,used sand in the pre-treatment prior to grinding and grinding dust generated during the effect of renewable. According to the effect of various factors on the impact of regeneration, to find the best renewable parameters,and put forward a reasonable process of regeneration.The experimental results show that:The higher the wheel speed, the better the effect of regeneration.And spacing is closely related to the wheel speed, too big or too small will affect the regeneration effect. Obtained through experiments the best regeneration of a group of parameters is that, Wheel speed:3000r/min(23.55m/s),spacing:3mm,time:60min.Under this parameter in the quality of reclaimed sand, contain of clay:0.42%,LOI:0.47%,Particle size distribution:55-100, System has reached the core of the quality requirements of sand.Core sand mix process system performance test:hot Wet tensile strength(δhot): 0.842 MPa,cool Wet tensile strength(δcool):1.784 MPa,better than the original sand core system performance.So, reclaimed sand can be operated hot-box.Reclaimed sand the surface of an inert membrane regeneration study found,the composition are clay boned, resin bonded and oolitic clay boned. However,large changes in morphology, no longer be the substrate is used resin bonded sand and its surface mulched clay-bonded film,but they were black "small plate" concave Department in sand.Renewable sources of Reclaimed sand clay membrane residues,the effective clay for 91.6%. the effective clay can be removed to further reduce the Reclaimed sand at the same time the contain of clay and LOI.In this paper, the regeneration mechanism of grinding wheel,the used sand in the grinding space additive resulting in a change in the way squeezing pressure.Rotation of the wheel so that they occurred in relative motion.In the sand-grinding wheel, sand-sand, sand-sand barrels of friction between the sand worn away the surface of inert membrane.The best space the size of grinding wheel speed and the related.Speed increases, the volume is also increasing trend.