Selection process of pure quartz sand

A method for preparing ultra-pure quartz sand, the production process thereof is:

1. Crushing and sieving: using natural silica as raw material, making silica into 2-6cm pieces of stone, mechanically pulverizing to make 20-200 mesh silica sand;

2. Hot acid leaching: the prepared silica sand is immersed in hot hydrochloric acid with a concentration of 25-40% and a temperature of 25-36 degrees for 60-82 hours;

3. Washing: remove the hot acid immersed sand and wash it to neutral and dry;

4. Cold explosion: Put the dried sand into a special refrigeration machine to make it reach 200-300 degrees below zero, and suddenly put it into a high-temperature furnace with a temperature of 400-550 degrees to achieve the purpose of micro-explosion. Producing numerous warp and weft cracks on the surface of the sand to melt the minerals inside the sand in the next pickling;

5. Ultrasonic vibration pickling: The cold explosive sand material is put into the ultrasonic container and washed with aqua regia acid for 6-10 hours. The purpose of ultrasonic vibration is to enhance the dissolution power of the mineral foreign matter inside the crystal nucleus;

6. High temperature dehydroxylation: The ultrasonic material after ultrasonic vibration washing is washed with pure water to neutrality and dried, and put into high temperature calcination at 1450-1600 degrees to remove low temperature impurities and hydroxyl groups.

Deep Drawing is a Sheet Metal Fabrication process in which a sheet metal blank is radially drawn into a forming die by the mechanical action of a punch. It is thus a shape transformation process with material retention. The process is considered "deep" drawing when the depth of the drawn part exceeds its diameter. This is achieved by redrawing the part through a series of dies. The flange region (sheet metal in the die shoulder area) experiences a radial drawing stress and a tangential compressive stress due to the material retention property. These compressive stressesesult in flange wrinkles (wrinkles of the first order). Wrinkles can be prevented by using a blank holder, the function of which is to facilitate controlled material flow into the die radius.