The intent of this trial was to see if the customer could derive benefits and reduce blasting costs by implementing some Titan technologies proposed for this mining complex.
This particular mine has been in operation for many years and traditionally used augured emulsion/ANFO blends only. Wet holes were dewatered and loaded with the same blend that would normally be used for dry hole applications. This meant the mine was able to utilize one pattern for both wet and dry holes in the same pattern. Patterns vary from bench to bench based on different geological formations found throughout the pit.
The mine drills 16” holes, and it is not uncommon for blast holes to be loaded and left uninitiated (slept) for several weeks at a time.
Water can be a problem in certain areas of the mine, making dewatering next to impossible. Several attempts have been made in past years to pump emulsion blends in an effort to solve the dewatering and prevent the NOx (post-blast fumes) problem associated with auguring product into wet holes.
The first tests
In the mid-2010s, traditional gassed emulsions were tested unsuccessfully. Most of the holes loaded with this product and technology failed to perform properly because the stemming material (sand, gravel or clay) used by the mine sank into the emulsion column. This caused the down lines to either sink into the blast hole or break depending on the amount of slumpage that occurred.
Because the mine had such a bad experience with gassed emulsions, the first series of tests were designed to demonstrate it had the capacity and capability to prevent the stemming material from migrating through the loaded emulsion column. An initial pattern was drilled, and 10 holes on the end of the pattern were loaded with Titan XL 1000. The holes were slept for several days. Each hole was monitored for slumpage during this time.
The outcome was positive: none of the holes slumped. Members of the blast crew indicated that this product seemed to resist slumpage better than the incumbent product. This pattern was initiated successfully, providing the initial confidence the mine operator needed to progress the testing program.
Positive results
Next, a series of patterns were partially loaded with Titan XL 1000 in order to compare a number of items side by side:
- Visual ground breakage
- Hole slumpage
- NOx emissions
- Loading rates (as compared to an augured blend)
- Cost reduction
Initial results were positive. Over a period of months, several entire patterns were loaded and shot using Titan XL 1000.
The results of the testing showed the visual ground breakage was very similar, the holes did not slump, NOx was eliminated entirely (improving safety) and production rates were equal. Although the trucks held less product, the delivery rate was 60% faster. The turnaround back at the plant took less than half the time it takes to turn the blend trucks. Equal or better performance was achieved even with a reduction in total pounds being loaded into the ground, reducing cost substantially.
A better solution
Several months passed as equipment was located and configured to meet the needs of the customer. When this was completed, the site converted 100% to the Titan technology.
A significant number of patterns were loaded and shot over a period of months after the new trucks arrived. The shots looked good from the surface, but as time went on, complaints started coming from some of the shovel operators about hard digging in the toe area of the shots. Based on this feedback, it was determined that Differential Energy, a system that delivers specific densities to match ground geography for each bore hole, might provide a better solution. After this technology was deployed, the hard toe issue went away.
Benefits included:
- The volume of explosives loaded into the bore hole was reduced up to 9.2% as the process transitioned from using heavy ANFO blends to Titan XL 1000 to Differential Energy.
- Powder factors were reduced 13.5% in many areas of the pit while still achieving excellent dig rates and crusher throughput.
- Post-blast NOx fumes have been eliminated.
- Trucks were specifically built to accommodate the loading rates required to maintain production.