3820847

Information

• Patent Grant
• 3820847

• References
• Source

• Patent Number

  3,820,847

• Date Filed

  Not available

• Date Issued

  Friday, June 28, 1974
  50 years ago

• CPC

  • E21C41/20 - for rock salt or potash salt
  • E21C37/16 - by fire-setting or by similar methods based on a heat effect

• US Classifications

  • 299 - Mining or in situ disintegration of hard material