Different soil conditions present different challenges for diamond drilling. As we have said often, choosing the right core bit for the type of ground in which you are drilling is an important decision. Non-stable and abrasive ground such as sand, gravel, or ground with pebbles and cobbles can be found in mineral exploration as well as in geotechnical drilling operations.
Abrasive ground, sand or other granular soil can wear down a drill bit prematurely, so you should consider customized bits are developed to drill through these types of ground, for example the Hero Abrasive line. This kind of customized bit has a special matrix made of alloys and diamonds that are very resistant to abrasive conditions so they penetrate well and last longer. The configuration is also important – customized bits usually have reinforced segments that help preserve the internal and external diameters of the crown. They should also have wider waterways so that rock cuttings can be flushed out easily.
Sandy soil is also difficult because it is unstable. A bore hole in sandy conditions can collapse onto your drilling equipment. Abrasive or sandy ground can also cause problems in recovering intact samples due to the granular nature of the ground. Often the sample will have a crumbly consistency which can break or fall apart during recovery.
We recommend that you take advantage of polymers or drilling fluid additives that are on the market and can make drilling operations more productive and efficient. One example is an additive such as Sand Drill. This particular type of polymer is used to solidify non-stable and abrasive grounds such as sand or gravel, and prevent collapsing walls. In addition to stabilizing the borehole, it helps with core retrieval. Its gel like consistency can hold together a crumbly core so that it can be retrieved intact.
Torqueless is a product that enhances all other polymers and should be added to every mix. It is an environmentally safe product can be used alone or in combination with other additives, to lubricate, reduce wear and rusting of the rods and cool the core bit. It ensures proper mixing with the water by encapsulating each grain of the polymer to ensure a thorough mix. It reduces clumping and waste of product, especially if you are using a powdered product.
Not everyone is familiar with how to use drilling additives, the best way to mix them and how to avoid common errors. Our technical support team has been helping clients get the most out of drilling additives for a long time. Following great feedback on our guide for overburden, we’ve published a new guide on using drilling additives for sandy ground that we think you’ll find useful.