In the mining industry, selecting between surface mining techniques and drilling and blasting is crucial to achieving maximum efficiency. Find out how a unified strategy transforms operations under challenging settings.

Whether you are mining limestone, bauxite, or one of the many other minerals found worldwide, you want the rocks to be broken down to a manageable size. On a mining site, your options are limited by the infrastructure and environment surrounding your work area.

You have two main options: You can drill and blast with explosives and size the rock with a primary crusher or use a Continuous Surface Mining (CSM) method. In most cases, the material being produced by a CSM is a consistent 5-inch to 10-inch (12.7-cm to 25.4-cm) range with few fines and can be fed directly into a secondary crusher if needed. The Vermeer Terrain Leveler® surface excavation machine (SEM), a Surface Miner, uses a top-down cutting method that delivers rock-penetrating power through its cutting teeth on a rear-mounted drum.

However, certain mining sites require the capabilities of both mining methods. The following are examples of how and when to consider continuous surface mining and drill and blast on the same mining site.

Infrastructure obstacles

Often, resources cannot be accessed or fully extracted with drill and blast due to proximity to public roads, urban encroachment, water and gas pipelines, wildlife and environmental challenges, or utilities above- or belowground.

So, what are your options? How do you get those areas you can’t reach with drill and blast? Those areas can often be extracted with continuous surface mining equipment, like the Vermeer T1255III Terrain Leveler SEM. 

This means ore bodies, once rendered inaccessible by drill and blast, could be incorporated into production. The rear-mounted drum of the Vermeer design allows the operator to cut inside and outside square corners and outer pit boundaries that centre-mounted drum machines cannot.

Environmental issues

Other times, you might run into environmental roadblocks. Dust, noise and seismic vibration issues can prevent you from drilling and blasting. That’s where surface mining can come in and be a neighborhood-friendly option. The Vermeer surface miner equipped with vacuum dust suppression reduces dust while mining. Since there are no high-energy explosives, there are no seismic vibrations or large dust clouds due to the blast, so you can continue to mine in areas even if these environmental issues are a concern.

In seams

Another way to use both methods is in seams, the layers in the rock formation that hold different chemistries, rock properties and minerals. After you drill and blast the overburden, you can use a continuous surface miner to accurately and precisely extract narrow seams of ore that would normally be blasted and hauled out with waste or where waste areas are mixed with quality material. The Vermeer surface miner allows you to precisely mine within a half-inch accuracy, so you can mine the seam completely without leaving massive amounts of waste rock or suffering enormous product dilution from the blast operation.

Overburden

There’s also an opportunity to use both methods regarding overburden on a mine site. Overburden is material above the desired ore product, such as a waste seam above different pit levels. The CSM method can cut the overburden and the valuable ore or mineral if you’d rather not drill and blast.

Large mines

Sometimes there’s more work to be done on large mines than just mining. There may be other areas around the site that need work or cleanup. A continuous surface miner can be used in these situations, such as road construction and maintenance and other civil engineering projects needed for the mine.

Top surface preparation

Finally, you can start with a CSM to prepare the top surface to save time on your job site. The initial overburden layer can often be too irregular in slope or flatness and marked with craters, making it very difficult for a drill rig to traverse. The Vermeer Terrain Leveler SEM can efficiently prepare the surface for the drill rigs to begin work. Then, you can complete the rest of the mining process with drill and blast or keep using CSM, whichever method you prefer.

While surface mining and drill and blast are mostly used separately, there are many opportunities for both methods to be beneficial on the same mining sites. Pairing drill blast and CSM together can enhance your mine site operation and help make your company more efficient and productive.