Anthony ‘Tony’ Graham is an expert in drill bits with over 60 years of industry experience. He was born in South Africa in 1940. He graduated the University of Natal with a BSc Hons in Geology. Tony then began working as a field geologist with Chartered Exploration (a division of Anglo American) in Lusaka, Northern Rhodesia (now Zambia), exploring for copper. Two years later, he moved back to South West Africa (now Namibia) to search for diamonds. Afterwards, he returned to Zambia to work for the Rhodesian Selection Trust (Rio Tinto) and later became an underground mine geologist at Mufulira Copper Mines.
In 1971, Tony began selling drilling products for Huddy Diamond in Southern Rhodesia (now Zimbabwe). After six years of selling drill bits across Africa, Tony moved to Sudbury, Canada and later to Vancouver. There, in 1986, he became a shareholder in Hobic Bit Manufacturing Company, which over the next decade grew to become one of the industry leaders. Their success attracted the attention of Atlas Copco, and they bought the company in 2002.
Over the next few years, Tony worked in the stone industry and products related to it. It was in 2009 when he and several experienced colleagues formed Diatool Diamond Products. The company now has sales outlets and distributors in Asia, Australia, India, South and West Africa, Scandinavia, South America, Canada and the US.
Grigor Topev: My first question is about your education. You have a BSc Hons degree in Geology from the University in Natal, South Africa. How did you decide to study Geology and pursue a career in this sphere?
Tony Graham: Growing up, I had no early interest in Geology, I was more interested in auto mechanics. After finishing school, I didn’t want to go to university and was coerced into trying accounting as that was my Dad’s profession.
However, after working in this field for a year, I found office work rather mundane and decided to attend university. I applied to enter General Science courses during my first year to keep my options open and studied Geology and Botany, Zoology and Geography. I found Geology very interesting, so I pursued this course as my major and after graduating carried on for another year, getting an Honours degree.
GT: You have worked in many countries. Which country left the strongest impression on you?
TG: I would say Nothern Rhodesia, which subsequently became Zambia, impressed me the most.
After graduating, I started as a field geologist working for Chartered Exploration, a division of Anglo American based in Lusaka. My job consisted of working in the bush searching for copper and other minerals for eight to nine months a year (from March to November). Then I would go back to the head office during the rainy season and plot up all the information gathered from the field, making and updating maps. From the information gathered, we would decide on an area of interest that needed further investigative work the following year.
Life was pretty simple back then, as before going into the field every year, we had predetermined the area we were going to cover from aerial photographs and we knew where we would establish a centralized base camp. Then once we arrived and had the base camp set up, we would go on a foot safari for up to two weeks before returning. We would go out again after two or three days of rest to cover the adjoining areas and repeat this until the whole area was covered. We had up to 10 porters, who carried our very basic provisions including a lightweight canvas stretcher for sleeping and a tiny strip of tarpaulin in case it rained, plus a small combo rifle over shotgun for meat. We used aerial photographs to determine where we would collect soil, stream and rock samples and also plot where all these samples had been consolidated from. We would leave the samples to be picked up by the Unimog (four- to six-wheel drive Mercedes bush vehicle) or by a small Bell 47 bubble helicopter, depending on the terrain to be encountered.
I did this type of work for two years before deciding to move to South West Africa (now Namibia) to work for Marine Diamonds exploring for and mining diamonds off the Skeleton Coast for 15 months. It took me several days of being sick as a dog before I got my sea legs. The swells and waves were very big and often rough the weather was tough, but I really enjoyed this work and learned a lot. But after a year, it became very repetitive and being confined to a small vessel at sea for three to six weeks at a time was not my thing. So I applied for a field geologist position on the Copperbelt.
GT: And which company had the most positive influence on your development as a professional?
TG: I would say it was Rhodesian Selection Trust, a division of Rio Tinto, for which I worked after leaving Marine Diamonds. I was initially a field geologist based in Kalulushi, near Kitwe, Zambia, on the Copperbelt. I spent two years in the field looking mainly for copper and other minerals. Operations were not as basic as my first field experience with Chartered Exploration. The field camps were bigger and had small landing strips allowing the access of personnel, provisions, etc. We would spend up to two months in the field, then back to the head office for a week or more to plot information, get assay results, etc., and it was back into camp again.
If anomalous readings were significant enough, pitting and or core drilling would take place. This was my first exposure to core drilling and it was baptism by fire, as on one project that I was in charge of, the drillers wanted to take the weekend off without permission from their head office. They asked me if I could cover for them and report progress. They showed me how to drill and I tried several times with supervision over the week before they took off.
On the first day of their absence, I did OK for a few hours, then stuck the rods and couldn’t get them out. I still reported the average footage they normally drilled for the two days they were absent. On their return, they had to work overtime with no pay to get things sorted and catch up. They did appreciate the break but weren’t impressed by what I had done.
After two years in the field, I applied to work as an underground gelogist at Mufulira Copper Mines, also owned by Rio Tinto, and was accepted. I spent the next four years there.
There was a lot to learn, but I appreciated being in a town and enjoyed the work and variety of daily challenges. The mine had its own drilling department, which came under the geology department. After my first year, I was one of the three geologists, who looked after procurements for the drilling department.
GT: So, this was your first exposure to drilling? It was mainly conventional at that time, right?
TG: Yes, that’s correct. There were twelve Canadian-made Boyles drills, all were screw feed air driven in an assortment of models, such as the BBU2, JVA and VEG. Drilling was conventional (non-wireline) in standard DCDMA sizes B, A and E. Hole depths varied from as little as 50 to over 300 m (164 to 984 ft) on the odd occasion.
I know that wireline actually came out in 1953 and was invented by Boart Longyear. But even when leaving Zambia in late 1970, all underground core drilling was still non-wireline.
GT: Continuing the topic of South Africa. I know that there were some deep holes drilled in the region, probably in the 1970s and the 1980s. Please elaborate on that.
TG: I have never worked in South Africa, but by hearsay, I believe that originally before wireline core drilling was introduced into South Africa, deep holes down to well over 2000 m (6562 ft) were using non-wireline standard rods like the BX and some of the holes even exceeded 3000 m (9843 ft).
These holes took up to six months or more to complete. The pre-starting site area would be cleared so the personnel could have their caravans as lodging and plant vegetables and other crops and even have chickens running around whilst the drilling was underway.
As mentioned, I myself didn’t work on these deep holes, which were mostly on the Witwatersrand goldfields around Johannesburg. In the early years, the big rigs were the Sullivan 50s that would go to more than 3000 m (9843 ft) plus using wireline on a regular basis.
I know that both Heath and Sherwood Drilling from Kirkland Lake (Canada) and Boart Longyear drilled some exceptionally deep holes there with modified wireline systems using aluminum rods with steel coupling wireline systems. Heath and Sherwood Drilling specifically were using their HNU system and their deepest hole reached 5422 m (17 792 ft), while Boart Longyear with their CUD96/CUD76 system reached a record depth of 5520 m (18 106 ft).
GT: Going back to when you were working underground with Rio Tinto at the Mufulira Copper Mines. Do you have any interesting memory from that time?
TG: I mentioned earlier that I was one of three geologists looking after the core drilling at the mine and all drilling was standard (non-wireline). Most of the holes drilled were to a maximum depth of 300 m (984 ft) and some of the rock was very hard, so it was very slow drilling. This was because the bits used were set with natural diamond and in you’d only get up to 30 m (98.4 ft) before you’d have to pull the rods.
It was an extremely laborious process to pull the rods, change the bit and then lower the rods back in and start the process again. We would do this probably every 40 or 50 m (131-164 ft).
Then in 1968 Atlas Copco approached us in the drilling department to give their subsidiary Craelius a contact to drill 10 000 m (33 0000 ft) using their small hydraulic drill. That was the Diamec 250 and their TT 46 mm non-wireline system and core bits. We agreed and we were surprised to see their production per shift double or triple what our normal production was. Their bits get three to five times the meters our surface-set bits did.
At the time, I was thinking, ‘Wow, this is an eye-opener’, so I checked to see what their drill bits looked like and was surprised to see that they were not surface-set, but impregnated.
GT: Can you tell us more about the story of the first synthetic diamond drill bit?
TG: Well, up until then (1968) we used to buy all our diamond bits from Boart Longyear and also from a company called Huddy Diamond Crown Setting Company Ltd (Huddy) which were natural surface-set bits. Whereas the bits that Atlas Copco introduced were synthetic diamonds. They went three to five times further than the bits from natural diamond we were using.
After that, it didn’t take long for Huddy and Boart Longyear representatives to take some samples and carry out reverse engineering. Huddy was the first company to come back to us offering their own drill bits with synthetic diamonds to test.
GT: How did you choose to move from geology to become a drill bit salesman?
TG: After four years of working underground in Zambia, lots of things were getting more difficult to get, so I decided it was time to move to Salisbury, Southern Rhodesia in 1971 (now Harare Zimbabwe), although I didn’t have a job to go to.
As I was settling in, most mineral companies shut down because of the political situation, and I couldn’t get a job as a geologist. So I approached Huddy Diamond, which was looking for a salesperson and decided to take the position.
Selling drill bits for Huddy Diamond worked well for me, as I knew about the company and their products from my time working at Mufulira Copper Mines. I enjoyed getting out to various field operations and mine sites, meeting people and trying to get them to try Huddy’s range of products, such as rods, core barrels, casing, drill bits, etc. and learned a lot as well.
GT: How big was Huddy at the time?
TG: Huddy was a small company compared to Boart Longyear, but relative to other manufacturers of diamond drill bits, they were the second biggest in Southern Africa with two factories, one in Johannesburg (main operation) and the one in Salisbury (now Harare, Zimbabwe). Scale-wise combined both factories produced between 1000 to 2000 bits manufactured per month in early 1970. At this time surface-set bits were 95% of the market.
Surface-set bits were labor-intensive to manufacture – making and setting mold, sintering, then sending the bit to the field. That was just half of the work.
After drilling minimal meters depending on formations being drilled, the diamonds in the bit would get glazed or become start penetrating slowly. So they would be pulled from the hole and returned to the manufacturer to be electrolytically removed. The used diamonds were sorted for stability of resetting and additional stones were added as needed, so they can be then sintered again.
So when impregnated bits started to work well, the number of surface-set bits decreased substantially.
GT: At some point, you moved to Canada. Looks like Huddy was expanding. Can you tell us more about that?
TG: Huddy, as mentioned earlier, was one of the first companies in Africa to manufacture a range of impregnated bits made with synthetic diamonds. However, there were impregnated bits made with natural blocky crushed diamond, which were mainly used if the rock was badly broken and/or very abrasive, or for drilling steel in the hole. The impregnated bits with synthetic diamond were much better, so they took over this market as well.
As Huddy was looking for new markets, they believed it could be beneficial to look at the Canadian market and try to introduce their range of impregnated bits. So in 1976, they asked me to do a market survey which I agreed to. Before leaving, I contacted the Canadian Diamond Drilling Association in Toronto and inquired which were the bigger contractors in Canada.
Upon arriving in Toronto, I made a trip to the Rouyn Noranda area and met with Bradley Brothers and then over to Kirkland Lake to meet with Heath and Sherwood Drilling, then to Winnipeg for MidWest Drilling, and then to Vancouver to see DW Coates and Tonto Drilling. These were the five biggest contractors in Canada and I dropped off a few synthetic impregnated drill bits for them to try. They were all somewhat skeptical, telling me that they had tried impregnated bits before, but they were just okay to drill out broken formations. Regardless, I dropped off a few bits and asked them to get back to me after they’ve tried them. They all did and were pleasantly surprised. Each of the five asked to purchase a few more bits to try.
So in 1977, Huddy asked me to move to Canada permanently and open a sales office. I did and set shop in Sudbury. It wasn’t easy getting the mines and most contractors to try impregnated bits as they still had a bad opinion of early impregnated bits, made with natural blocky grit or crushed natural diamond. However, as Boart Longyear and another manufacturer from North bay were also introducing impregnated bits, things became easier in late 1978 and impregnated bits started to take over Canada.
GT: So, let’s see if I have the story correct. First, it was bits with surface-set diamonds, then came impregnated, but with natural diamonds, and finally impregnated with synthetic. Is that correct?
TG: Yes, surface-set diamonds were what everyone used in about 95% of core drilling. Occasionally, if there was steel down the hole, surface-set diamonds would get damaged straightaway. So they used a very blocky industrial natural diamond grit along or with a crushed natural diamond which was embedded in a matrix. It was more wear-resistant and it was used to drill through any broken or abrasive rock and steel in the hole. Basically, that was the early impregnated natural diamond bit.
I’d say that nobody used synthetic diamonds until the late 1960s, even though they were first made in 1954. In general, synthetic diamond was much tougher and finer, cheaper, and it penetrated faster.
Initially, you’d use at least three times the amount of natural diamond bits to get the same meters drilled using impregnated bits with synthetic diamonds. When they were first marketed, they were very expensive, but because they did three times the work. Since you had to send back the natural diamonds for a burn out then pay for setting and diamond charge, using an impregnated bit made with synthetic diamond was a no-brainer.
It didn’t take long for the impregnated bits made with synthetic diamonds to take over probably 95-98% of drilling. By the late 1970s or early 1980s, synthetic diamonds were dominant, although in some softer rock types like coal formations, natural surface-set diamonds were still used.
GT: Talking about a good-quality impregnated drill bit, is the secret in the matrix (the binding compound) or the diamonds themselves? Which one is more important?
TG: I would say it’s a combination of all many factors. All are of equal importance.
The physical pressure applied before or during sintering, plus the furnacing type used, for example, hotpress induction temperature and so on is important, of course.
Naturally, the quality of the synthetic diamonds being used plus size coatings are of importance as well as the powders, etc. When it comes to synthetic diamonds, there are at least four big manufacturers, all of whom have excellent products.
GT: And you mentioned that silver was used. Are the tendencies changing with the years?
TG: There are a variety of different metals normally used as a combination in binder materials. Yes, silver is still one of the important ingredients used.
In general, silver can be one the most important components used in some binders for drilling extremely hard fine-grained non-abrasive rock types since often, faster penetration with less pressure is achieved.
Like everything else, the price of silver has gone up from less than USD 5 per ounce in the early 1990s to USD 24 today, so it can be a big cost depending on the percentage used.
I should note that there are several other binder materials with no silver used commonly that work well, especially for medium to softer broken formations. Generalizing most matrix types in the 1-6 range tend to have no silver in the binders, whilst most in the 7 and above range will have some silver.
GT: Let’s move on, you became a shareholder of Hobic Bit Manufacturing Company in 1986. Tell us more about that.
TG: I guess as I had worked for Huddy Diamond from 1971 and they asked me to come to Canada in 1977. Then I spent the next nine years selling drill bits for them.
So when John Huddy, who was the owner of Huddy, Rhodesia, whom I worked for, emigrated to the US, he started selling bits out of Denver. John heard that a company in Edmonton that made oil bits had gone into receivership. Since Huddy Diamond was also making oil bits in South Africa, mainly for Iran and a couple of other countries, John went to see the operation and made an offer. He purchased the company and invited me to become a minor partner which I did. This was in 1986. We started manufacturing and selling oil bits, but the market was very competitive, and we were hardly making any money.
So after three years, we decided to start making core drilling bits as well. We had to make some money. We used the same name for our mining bits which was Hobic, an acronym for Huddy Oil Bit Industry Corporation. We moved to Vancouver in 1990.
Four years later, after we had completely stopped making oil bits, John Huddy decided to sell his share. I bought some of it and a venture capitalist bought a small share. We carried on manufacturing diamond bits and our market share increased considerably until we became one of the prominent manufacturers in Canada.
As a result of our success, in March 2000, a manager from Atlas Copco approached me at our booth at PDAC and asked me, ‘Do you have time for a coffee?’. I said sure and they broached a question as to whether we may be interested in selling the company. I discussed this with my partners when I got back, and we were all happy to move on.
By September 2002, they had purchased the company. I worked for Atlas Copco for two years then got involved in the stone industry. We came to a gentlemen’s agreement with Atlas Copco to stay away from the bit manufacturing business for a while.
In early 2010, with a few associates, who have many years working for the major manufacturers, we formed a new core bit manufacturing company called Diatool Diamond Products.
GT: Do you think we will see any new developments in the next years in diamond drilling manufacturing? Do you think something will change dramatically?
TG: One would think that someone would come up with some sort of a new technology that would deliver a significant increase in penetration and footage drilled per bit, but I am not sure what it would be.
I remember that people were trying to develop a retractor bit, which could be replaced from down the hole. That didn’t quite take off and I don’t think that there has been any significant breakthrough in the last, I’d say, ten years.
Originally, impregnated bits when they first came in, were 3 mm. Then they went to 5 mm, and then to 6 mm. Then people went to 9 mm and stayed there for a long time and then it was 12 mm, and later 16 mm, and 20-24 mm and even some 30 mm bits. These incremental increases in impregnated depth have resulted in keeping bits down the hole longer.
Drills have been computerized and there are autonomous rod handling systems that have proved to be a great benefit in productivity and safety. So a combination of these three has certainly benefited the industry, but as far as replacing a core bit, it’s hard to envisage what this will be!
GT: I think there is a lot of marketing involved in the growth of matrix depth. From my experience, those high matrixes are not suitable for all conditions. So, you are not saving money with them, rather you are spending more. Do you have a similar observation?
TG: Most manufacturers have found that there are only a limited amount of contractors with the expertise and the right ground conditions to fully utilize the 20 mm or deeper depth of impregnation.
Global usage, I would say, for 20 to 30 mm would be in the range of 5 to 10% of sales, 16 mm about 25%, 9-13 mm 50%, and the rest would be less than 9 mm.
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