On Used Sand Reclamation
According to the calculation and statistics, the Fused ceramic sand shell casting process requires 1.5 ~ 2 tons of coated sand (core) per ton of castings. In this way, the treatment of used sand becomes the most critical link of this process. This is not only the need to reduce manufacturing costs and improve economic efficiency, but also the need to reduce waste emissions, realize circular economy, live in harmony with the environment and achieve sustainable development.
Purpose of Fused Resin-coated Ceramic Sand Reclamation
The purpose of fused resin-coated ceramic sand regeneration is to remove the residual resin film coated on the sand surface and remove the residual metal and other impurities in the old sand. These residues seriously affect the strength and toughness of the re-coated ceramic sand, and at the same time increase the gas generation and the probability of waste products. Generally, the quality requirements for reclaimed sand are as follows:
loss on ignition (LOI) <0.3% (or gas generation <0.5ml/g).
The performance of reclaimed sand after film mulching has little difference from that of new sand. The coated sand uses thermoplastic phenolic resin as binder, and its resin film is semi ductile. In theory, both thermal and mechanical methods can remove the residual resin film. Thermal regeneration is the most effective regeneration method, which utilizes the mechanism of carbonization of resin film at high temperature.
Thermal Regeneration Process of Fused Ceramic Sand
With regard to the thermal regeneration process of fused resin-coated ceramic sand, research units and some manufacturers have carried out a large number of experimental studies. At present, it tends to the following process, the roasting furnace temperature is 700℃ ~ 750℃, and the sand temperature is 650℃ ~ 700℃. The regeneration process is :
(vibration crushing) → magnetic separator + waste sand preheating → (bucket elevator) → (screw feeder) → reclaimed sand storage bucket → boiling fan → boiling cooling bed → dust removal system → core sand powder → bucket elevator + flue gas discharge - + waste sand transportation → fluidized roasting furnace → intermediate sand bucket → film coated sand production line.
In terms of Fused ceramic sand regeneration equipment, thermal regeneration is generally adopted. The energy sources include electricity, gas, coal (coke), biomass fuel, etc., and the heat exchange methods include contact type and gas flow boiling type. In addition to some well-known large companies having relatively mature recycling equipment, many small enterprises also have many ingenious recycling equipment built by themselves.
For most foundries that produce small and medium-sized pieces, the iron sand ratio can reach 1:1 or even higher in many cases. After pouring, the core sand is basically burned through, so it is necessary to test mechanical regeneration on this basis to confirm the regeneration effect.
Fused Resin-coated Ceramic Sand Manufacturer
The Fused Resin-Coated Ceramic Sand manufactured by Sanrmenxai Qiangxin Foundry Material Co., Ltd. adopts fully automatic visual production technology, and the heating temperature, feeding time and sand mixing process are accurately controlled, which effectively ensures the reliability of the performance. Qaingxin has increased investment in scientific research and solved the problem of waste sand recycling, so that the reclamation rate of waste sand has surpassed 95%, and achieved social benefits and enterprise benefits jointly improvement.