Thanks to its rich gold deposits, the Cajamarca region in northern Perú has been home to gold mines since the Inca times. One of the current mines is Cerro Corona, where Robit recently became the preferred supplier of DTH drill bits.
Cerro Corona mine, owned by Gold Fields Inc, is located on the eastern slope of the western Andes, some 80 km north of the regional capital of Cajamarca. The open pit mine is expected to produce some 2.1 Moz (about 60,000 kg) of gold and 407 kt of copper in concentrate over its 15-year mine life.
The rich gold deposit is hosted by diorite porphyry, an extremely hard rock embedded in limestone. MUR-WY, the drilling contractor at Cerro Corona, uses the so-called pre-splitting method, where closely spaced holes are drilled and lightly charged, causing fractures that isolate the gold-bearing rock from the surrounding rock mass. Successful pre-splitting requires very straight holes, and, as always, this should be achieved with optimal cost, penetration rate, and tool lifetime performance.
Robit believed their tools might improve productivity, so they contacted MUR-WY in 2021 to arrange test drillings for 5” DTH bits at Cerro Corona. Test drilling is typically a very hands-on type of work where you monitor and make adjustments on the spot with the contractor. However, the COVID pandemic complicated things.
“In 2021, access to the mine was heavily restricted, so we had to get creative with MUR-WY to follow up on the tests. We ended up monitoring the performance remotely through WhatsApp videos and messages”, says José Luis Cisneros, General Manager of Robit SAC.
Luckily the restrictions were eventually lifted, and Robit’s Regional Sales Manager, Martín Rodriguez, was able to revisit Cerro Corona and conclude the tests, which proved highly successful.
“On average, compared to the tools they had used, we reached 20 to 25% better yields with our DHD340 Flat Face Premium bits and 40 to 50% better with our D45 HD hammers.
“We detected several ways to improve productivity. Not only did Robit’s components perform better, but a key factor is also the service we can provide. We are now the preferred supplier for DTH consumables at Cerro Corona. There are still challenges to tackle, but we will work with our strategic partners from MRU-WY to articulate better ways to approach their needs and increase security regarding the project’s required logistics”, Martín says.
When developing products for use under several conditions, it is vital to consider the experiences of people using the products. In modern times, it is possible to simulate all sorts of conditions in a lab environment or using computer models. But these can often only give an indication of the product’s performance in the real world, whereas those working in the conditions set by said real world can tell you a lot more.
For the above reasons, Robit has a long tradition of working with its distributor partners and end-customers alike regarding product development. The end-users know their equipment and circumstances better than anyone, so they can often test new and existing products under true-to-life conditions. This way, one can ensure that the test results correspond to the products’ actual performance and durability capabilities.
Collaborating towards better efficiency
One of Robit’s long-term test partners is Stevin Rock, which operates a limestone quarry in the United Arab Emirates with a fleet of Down the Hole (DTH) machinery. They have been using Robit-manufactured DTH tools since 2016. Stevin Rock has been using the full suite of Robit’s drilling consumables, with a 4″ hammer as their workhorse of choice and adaptors, drill tubes, and 110 mm and 127 mm bits aiding the work.
The initial contract was made after Robit succeeded in the trials at the Stevin Rock quarry. Robit’s products triumphed with a longer life span and lower cost per meter than the competition at the time. While some alternatives provided a higher penetration rate, this benefit was trumped by the higher number of breakages it brought. They decided to go with Robit, which offered known products that provided conclusive and consistent high performance.
In the years since the initial contract, Robit has proven itself as the right choice with an excellent overall life span of products, a high level of service, and numerous supporting drill master visits. Indeed, these visits have been the core of the support and collaboration towards the customer. A Robit drill master has been visiting the site on support duties a couple of times a year to help Stevin Rock optimize their processes. In addition, Robit and their distributor partner DeltaCorp Global have conducted on-site practical and theoretical training sessions for the operators and mechanic teams on hammer assembly, preventative maintenance, bit wear, failure modes, and best drilling practices.
Robit always aims to find the best possible distributors for each region; the goal is to find those who understand the local market, culture, and general thinking. In DeltaCorp Global, Robit has one such winner. During the years, DeltaCorp has fostered a very close working relationship with Stevin Rock. This allows them to consistently offer timely and relevant support for the customer across their organization. DeltaCorp’s representatives conduct at least one visit each week to one of Stevin Rock’s three sites. The purpose of the visits ranges from stock deliveries to management meetings, where product quality and life span, as well as stock levels and forecasts, are assessed. While on-site, the representatives will also visit the drill rigs to receive direct feedback from the drill operators. On top of all that, the DeltaCorp representatives maintain constant communication with Stevin Rock’s site management, working swiftly in the event any concerns should be raised, such as a sudden need for urgent deliveries, an unforeseen breakage, or some other operational problem.
Thanks to continuous support, Stevin Rock has improved the results they get with their equipment even further. When the initial contract started in 2016, the average life span of a drill bit was 2,000 meters, with hammers reaching approximately 8,000 meters. With all the training given to the personnel to help them make the most out of their tools, the efforts to optimize the drilling processes, as well as the product improvements from Robit’s Engineering and Production teams that based on the customer’s feedback, the average bit life span has extended to 4,500 meters, with the hammers regularly exceeding 25,000 meters.
While the durability and solid performance of the drilling consumables first made Stevin Rock give Robit’s drilling tools a chance, they have since gotten several more reasons to stick to their decision. And while they have been periodically testing multiple competing products, they have not had a reason to switch.
“We have been using Robit’s products for years and cannot fault their performance or service. We run an open tender every two years, and they always come out on top. Robit’s commitment to collaboration and continuous improvement is their great strength. However, their local Distribution Partner is also strong; with their reliable supply chain management and quick reaction times, a solution is always available to us 24/7.”
Stevin Rock Operations Manager Brian Howard under the Arabian sun.
Collaboration as the basis for product development
During their years working with Stevin Rock, Robit has been conducting numerous tests on many hammers and bits. All these tests have aimed to increase the life span of the products, as well as their performance, with minimal downtime and breakages so that the customer can reduce their drilling costs to the minimum. Tests carried out with customers have been at the heart of Robit’s product development process. Those trials have led to discoveries and breakthroughs that have guided the designs of their latest products, with the upcoming H-series hammers as a good reference point.
The new H-series hammers have been designed with performance and versatility as their guiding principles. The goal was to provide customers with a hammer range that they could utilize in different environments with minimal breakages and maximized utility for each operator’s circumstances. Customer feedback led Robit to develop a new modular design, offering increased flexibility and adaptability to varying conditions. With a few simple changes in the assembly of the hammer, the user can customize it for their needs; whether one wants to run them with improved productivity in mind or needs to be able to use a lower capacity compressor, the H-series hammers can be modeled to suit these requirements.
In practice, the modular design allows Robit to offer four hammers in one base design. The assemblies vary between high power and low volume, as well as foot valved and tubeless. Thus the following variations are available: high power with a foot valve, high power tubeless, low volume with a foot valve, and low volume tubeless. The high-power assembly offers high blow energy and air volume, resulting in a fast penetration rate and is suitable for deep-hole drilling. On the other hand, the low-volume assembly provides lower blow energy and air consumption, which are ideal for soft ground while keeping the hammer energy efficient.
As an example, Stevin Rock was looking for a faster drilling hammer to improve the potential productivity. Robit provided them with two assemblies of the new H-series models with differing internal arrangements to control the airflow, one with low air volume and the other with high air volume. These new hammers were to be tested against the tried-and-true D45 hammer from Robit’s older hammer range. The tests showed a considerable, consistent improvement across the board. The penetration rates went up in all tests, with the smallest increase at 14% and the most significant improvement at 30%. The highest penetration rate reached during the tests was 63.18 meters per hour. These results also correlated with those seen in earlier trials, ensuring the validity of the results.
With the new hammer range, Robit wants to bring more options to the market while still guaranteeing high performance. Because if one thing has become crystal clear during their collaboration with their customers, no two drill sites are the same. For this reason, they will make sure to let their customers’ and distribution partners’ voices be heard when developing new products and improving on the old ones.
This is an edited version of an article originally published in Global Mining Review, May 2023.
Imagine an offer where you, a mining company, are promised 5% cost savings on drilling consumables. If your supplier does not meet the promise, you only pay 20% of the going rate on said consumables. Would you be interested?
That is the core idea of the new RobitSave site audit program. Sales Director Kimmo Kangas explains the concept in more detail.
“Once we have identified and contacted a potential customer, our drillmaster visits their job site, surveys the relevant drilling tools they use, and documents their performance.
“The drillmaster does not make or recommend any changes in the setup; they merely observe and numerically records the performance: penetration rate in meters/minute, the lifetime of the tools, et cetera. Once they have collected enough data – in our pilot project, this took a week – they write a report. That concludes stage 1.
“In stage 2, we supply the customer with Robit tools for the same tasks. Up front, we charge 20% of the going rate of our products while promising 5% cost savings compared to their current supplier. And here’s the beautiful part for the customer: if we don’t reach those 5% savings – we will not charge a cent more”, Kimmo explains.
The RobitSave program was first piloted at the Kemi chromium mine – the only one of its kind in the European Union – run by Outokumpu Chrome. Kemi quarries some 3 million tons of rock yearly (two-thirds ore, one-third waste rock), and the expected remaining lifetime of the mine is 30–50 years.
The RobitSave test at Kemi covered cable bolting and production drilling consumables. As per the RobitSave contract, Robit charged 20% of the price of the goods upfront. In total, the tests at the Kemi mine took some two months.
“It went extremely well. We had all the results in black and white; our calculation chart showed undeniably that the cost-per-meter savings were way above the 5% we had promised. Our customer was positively surprised, and we could charge the remaining 80%”, Kimmo says.
The coming months and years will see the RobitSave site audit program gradually deployed across all of Robit’s markets.
In the winter of 1986, a road construction job was underway in Kittilä, Finnish Lapland. Some rock was blasted, and out of curiosity, a geologist working nearby decided to examine the boulders – and found something. Today it is the site of the largest gold mine in Europe.
Gold was found in several boulders, and the Geological Survey of Finland began prospecting the site. The deposits turned out to be quite rich. More than twenty years passed until gold mining finally began in the Kittilä mine; first in an open pit in 2008, and underground a couple of years later.
Since 2012, mining in Kittilä has been exclusively underground. Today, Agnico Eagle Finland extracts some two million tonnes of ore each year, with annual gold production of around 7,000 kilograms.
Since May 2021, Robit has been supplying drilling tools to the Kittilä mine under a long-term contract. This includes, among other things, a turnkey drillmaster service, including a sharpening service. Robit supplies the products from their consignment stock, located 350 metres underground in the mine.
In Kittilä, Robit is dedicated to finding ways to cut costs per drill meter in cooperation with the customer. When the need arises, tailor-made products can be developed to meet the customer’s needs. A case in point is cable bolting, a common method used in underground mining to reinforce the rock before extraction.
“Cable bolting posed some problems. The drilling gear did not work properly in broken rock; the flushings escaped into the rock fractures and the drill bit would get stuck,” says Kimmo Kangas, Sales Manager at Robit.
“We suspected that the problem was caused by the side flushing of the bit. Our customer tried what would happen if you welded the side flushing shut – and it helped. We then made a series of bits at the Lempäälä factory that were modified in the same way,” says Kimmo.
Robit’s R&D Engineer Mika Koskinen was closely involved in the development work. “The results improved, but not quite enough. We discussed this with the bolting rig operators, trying to figure out what to do next. Based on the mining company’s views and our own design ideas, we developed the second iteration of the bit, which was substantially different. It finally solved the flushing problems, and drill meters began to reach excellent levels,” says Mika.
The new high-performance drill bit has been in use at the Kittilä mine since early 2022. Plenty remains to be drilled, as the mine is expected to operate until 2034 with the current ore reserves and production volumes. By then, new deposits may well be discovered in the course of prospecting.
Carbon neutrality is a globally accepted goal to minimise the negative effects of climate change, in which energy production plays a key role. The current military crisis in Europe is a reminder that nations should also strive for maximal energy self-sufficiency. Geothermal energy provides one promising, cost-effective path toward achieving both goals.
In Finland, the growth of geo-energy has been rapid in recent years. One of the key actors in the sector is Rototec, Europe’s largest geo-energy company with more than 60,000 energy wells drilled. Founded in 2007, Rototec has grown strongly in Finland and operates also in Sweden and Norway.
While geothermal energy has long been a popular energy source for single-family houses, Rototec is focusing more on supplying geo-energy for large properties such as hospitals, shopping centres, and factories.
A geothermal system requires one or more bore wells, drilled to a depth of 150–250 metres, depending on the amount of energy required. Robit has been supplying Rototec with drilling tools since the early years of the company.
“Robit, as a big domestic manufacturer, was a natural choice for us. 99% of the holes we drill are four-inch wells and Robit has a comprehensive line of tools for that. Currently, all our drill bits are from Robit,” says Hannu Puolitaival, Technical Director at Rototec.
The fruitful, mutually beneficial cooperation spans back more than a decade and focuses on customer-oriented service.
“Over the years, we have worked closely together to develop drill bits to better meet our needs. We test the products, and share our experience and comments with Robit for further development. One of Robit’s assets is their agility: after our feedback, they can produce new, improved prototypes at a fast pace for testing. Of course, the fact that they have domestic manufacturing helps too,” Hannu says.
“Another strength is that Robit can make small batches. If we’d need, say, five units of a particular new drill bit for testing, that poses no problem. Not all manufacturers can do this,” says Hannu, and adds one more thing: “I have especially liked the fact that Robit has a dedicated person managing all communication with us. It makes our cooperation seamless and straightforward.”
