Blasting

After workers have drilled the blasting holes, blasting takes place. Blasting is important because it loosens the rock above an ore seam so that miners can remove the ore. After the topsoil and subsoil layers have been removed and stockpiled for later land reclamation, and blasting holes have been drilled, it is time for explosives and stemming material to be loaded.

Dynamite is not commonly used within surface mining. Instead, blasters use a blasting agent called ANFO, which is a mixture of ammonium nitrate and fuel oil. To control the blast, it is essential that the blaster carefully calculate the amount of blasting agent to fill the drill holes. It is a violation of law if property nearby is damaged by flying rock or powerful vibrations.

Public Notification of Blasting

Requirements vary from state to state, but mining companies must typically notify the public if blasting is going to take place nearby. Mining companies are required to develop a detailed blasting plan that will demonstrate how blasting will be conducted to prevent damage. A certified blaster is in charge of conducting or directly supervising the loading and detonation of all surface mine blasts. Before blasting, the operator must sound a warning sound to clear the blasting area.

Conditions for Blasting

The following are more conditions that must be met for blasting to occur:

• The blast area must be strongly restricted to prevent miners and others from becoming seriously injured.
• Blasting must not be conducted within 300 feet of a school, church, or hospital.
• Records of all blasts, including seismograph recordings and reports, must be maintained for a minimum of three years and must be made available for public inspection at the mine site.

To learn more about MSHA Part 48 training requirements visit our MSHA Part 48 Subpart B Surface Mining Online Training web page.