With the rapid development of foundry industry, people's requirements for production technology, casting quality and labor environment have been continuously improved. Foundry scholars are not satisfied with the use of common sand at present, and began to use fused ceramic sand to replace it.
Fused ceramic sand is a new type of artificial sand with spherical particles and excellent properties. It has been used in high manganese steel castings, large steel castings and other aspects, and has achieved satisfactory results.
But at present, the technology, equipment and experience of fused ceramic sand reclamation are still blank, and no in-depth research has been carried out, which limits the popularization and application of fused ceramic sand.
Analysis of Used sand reclamation of fused ceramic sand
According to the characteristics of Fused ceramic sand and the characteristics of the binder on the surface of the used sand, two kinds of regeneration process schemes, wet regeneration process and thermal regeneration process, were selected to test and analyze the 24h tensile strength and loss on ignition performance of Fused ceramic sand after regeneration, and the microstructure was observed, Finally, the following conclusions are drawn: the wet regeneration process is used to regenerate the Used Fused ceramic sand. The optimal process parameters are as follows: the temperature of sand water mixture is 60 ℃, scrubbing for 6 times, the sand water mass ratio is 1:1.5, and stirring for 20min. The regenerated Fused ceramic sand has a round shape, no obvious change in particle size, and the particle surface is clean, tidy, without undulation, depression, etc. the alkaline phenolic resin film is basically removed, A small amount of binder remains in the micro pores of Fused ceramic sand.
The ignition loss of recycled fused ceramic sand is 1.975%, and the 24h tensile strength is 0.673mpa, which is close to that of new sand.
Analysis of advantages and disadvantages of fused ceramic sand thermal regeneration
The thermal regeneration process was used to regenerate Fused ceramic sand, and the optimal experimental conditions were obtained as follows: heating time 20min, heating temperature 550 ℃. The regenerated fused ceramic sand obtained by this method is round, clean, and the loss on ignition is 0.51%. The sand particles are exposed to the original surface, and the binder is completely removed, and only a small amount of needle like alkaline phenolic resin remains on the sand surface.
A small amount of needle like alkaline phenolic resin remained on the surface of recycled sand obtained by fused ceramic sand thermal regeneration process.
Analysis of advantages and disadvantages of fused ceramic sand Wet regeneration
The surface of reclaimed sand obtained by fused ceramic sand Wet recycling process is clean, and only a small amount of porous binder remains in the micro pores. In contrast, it is more effective for fused ceramic sand Wet recycling process, with higher quality and better performance.
However, the wet regeneration process will produce sewage, which needs to be equipped with corresponding equipment for treatment in the later stage; The thermal regeneration process equipment has simple structure and convenient operation, while the wet regeneration process equipment occupies a large area and has complex structure; The thermal regeneration process converts electrical energy into thermal energy, consumes fuel to roast the used Fused ceramic sand at high temperature, and the wet regeneration process converts electrical energy into mechanical energy to scrub the used sand flexibly.