... 6-8 hours.3. Processing good quality, use this kind shot blasting machine, the processing quality ... need to pay a heavy physical labor. 6. Use less sand, traditional method need more than 20T sands, ... sand, and can be recycle. 7. The one-time investment is small, only about 30% -40% of ... machine advantages: 1. Automatic closed circuit recycle system, less sand input, and not lose. Input volumn about ...