Because of historical closed type of blasting pit is now used in many places.During production it has a great noise and vibration and also is often harmful to human due to flying crushed scrapes.

 
  • 封閉式爆破坑生產(chǎn)時(shí)振動(dòng)大、噪聲大,并且經(jīng)常有碎塊飛出傷人,國家已規定不允許使用。
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