HOW TO CHOOSE BITS FOR SALT MINING

By: Scott Bahr

Carbide bit selection in underground mining is an important process that requires a deep knowledge of the cutting needs, mining methods, and challenges the ore body presents. When selecting a carbide bit, there are many factors you need to consider, including the penetration rate, wear resistance to overcome abrasive material, and dust generation. While some elements can be compromised to emphasize others, the mine operators need to maximize production while also being careful not to increase the strain of a heightened need for ensuring operator safety in the mine.

UNIQUE CHALLENGES OF UNDERGROUND SALT MINING

Underground salt mining presents its own unique set of challenges, including the material involved in this type of mining. While it’s easier to cut than you would see in a typical hard rock mine, the salt poses more than a few difficulties in heat generation and wear. These unique problems must be overcome to produce long-lasting and productive mining methods.

Using modern continuous mining methods, the carbide-tipped conical bits in use are presented with the challenge of having high penetration rates, which are typically provided by a slender bit body and carbide profile, allowing for maximizing contact pressure on the face. This, however, is offset by the nature of the ore body, which resists this cutting action, resulting in high thermal levels and wear due to the friction of the cutting action.

Increasing the induced cross-sectional area of the bit profile results in the bit’s ability to hold up better to the forces and wear rates involved. Unfortunately, this comes at the expense of increased dust generation.

The increased dust is the ore body experiencing a higher degree of crushing while being cut. As opposed to a pure fracture, this then leads to issues of transporting the material to the surface, processing issues in the surface facility, and also creates an increased amount of respirable dust particles that negatively affect operator health and safety.

INNOVATIVE SOLUTIONS

Bit Service, along with our partners at Kennametal, work with the clients to provide cuttingedge solutions which address this very concern. One involves innovations in material selection providing carbide grades and carbide inserts better suited to resisting the thermal and wear challenges. Specialized coatings and protective treatments allow the bits to maintain a desirable body profile while resisting the challenges imposed by the mining conditions. Another key element is using carbide insert profiles designed to maximize penetration, while also maintaining the needed cross-section and mass to protect the bit body.

Working closely with the underground mine operators is important to ensure we are tailoring the specific selection to the unique needs of the mine. We invite you to reach out to our team at Bit Service to discuss how we can help you reach your goals of productivity improvement at your site.