Today we visited the Jwaneng diamond mine, also known as the world’s richest diamond mining operation. The mine, an open pit over 500 m deep, consists of three diamond bearing kimberlite pipes which produce about 12 million carats of diamonds per year. To put that into perspective, at about 70 million carats of diamonds are mined per year in Botswana where diamond mining contributes 70%, yes 70%, of the country’s GDP—12% of which comes from Jwaneng. As a comparison, despite Canada being one of the world’s largest producers of diamonds, gold, copper, nickel, and coal, mining only contributes 4% to the nation’s GDP. Botswana gained its independence from being a British protectorate 40 years ago, and due to the diamond industry—and operations like Jwaneng which is now 35 years old—Botswana has rapidly grown into one of the strongest economies on the African continent.
Many may ask the same question I did, is what happens to Botswana if the diamonds run out? Or if nobody wants to buy a diamond anymore? I was relieved to see that the country has by no means made an oversight here. Back in 2010 and economic crisis saw a crash in the nation’s GDP by almost half which correlated to nationwide diamond production. The economy has since recovered, however the production rate of diamonds has remained low relative to pre-crisis times. Other industries, especially tourism, have begun to grow throughout the country which has helped to diversify the nation’s assets. On top of this, the country has made significant moves to become not only a rough-diamond supplier, but also a diamond cutter, jeweler, and overall hub for the global market (you should remember some of this from yesterday’s post about our visit to the Diamond Trading Centre). However, one should keep in mind that the country currently has resources to continue supplying diamonds to the world market beyond the year 2050.
Now for our visit . . . As said by one of our hosts, I wish we could have spent the night in town so that we could have spent more time at the mine. There was so much to learn and see that we have never been exposed to in Canada! Our tour of the mine started at 10:30 am, to which you may say, “What a bunch of lazy mining engineers sleeping in when they should be learning and exploring!” I would agree, except when you take into account the hour it took to clear security (permits and passports mandatory!) and the two hour drive to the mine we had yet another 5:30 am early morning. I was very impressed by the security measures that existed on site, which starts from the pit floor and goes all the way up to government regulations. The site has 4 levels of security and we went to level 2 (blue)—luckily only level 4 (red) zones require a strip search on the way out... What was cool to learn, is that since diamonds are of such importance to the nation’s economy there are very strict laws around producing them. In fact, simply having a rough diamond in your possession without a government permit is punishable by up to 15 years in prison. So what happens if you find a diamond on site? Well, you stand where you are (but don’t touch the diamond!) and wait for someone to walk by at which point security is called to come and take the stone to a secure sorting facility. On the bright side, if you find a diamond you will be given 30% of the stone’s value up to a maximum of 30,000 pula (about US$3000).
Fun fact, the nation’s currency “Pula” translates directly to Rain.
When we first arrived on site, we were brought into the boardroom for an introduction to the operation and its safety practices. They were very proud to share, as they should be, that there incident rate has steadily decreased such that in 2016 they had a lower injury rate than all Anglo American, Newmont, Rio Tinto, and BHP. They also told us about their sustainability and community engagement practices. The two most impressive things that stood out to me were (1) the entire mine is surrounded by a game park full of wild animals—like a doughnut where the doughnut hole is a giant diamond mine—and (2) Debswana spends P162M (about US$16.2M) per annum on two hospitals in the country which service a large part of the nation’s population.
Outside the boardroom, our first stop was a viewing station of the entire open pit. It’s hard to imagine something of such scale, but at 500 m deep you can barely see a person standing at the bottom of the mine. For our followers in Vancouver, if you look across the water to the North Shore, Grouse Mountain is about 700 m tall from its base. So, imagine a hole in the ground that can fit more than 2/3 of Grouse Mountain within its boundaries! This is what you can achieve with 35 years of constant operation and trucks that can carry over 300 tonnes (300,000 kg or 660,000 lb). Looking down on the pit, you can see drills, shovels, haul trucks, dozers, and more milling about to haul ore and waste to the surface. For a quick geology lesson, diamonds are typically found in Kimberlite pipes which are the remnants of volcanic activity which push a “pipe” of material from below. This forms kimberlite rock which is disseminated with diamond stones. At Jwaneng, there are three kimberlite pipes which can be clearly seen from the viewing platform above. The greenish rings of the south, north, and centre pipes stick out clearly amongst the red stone which surrounds them (there is also a very small fourth pipe but it represents a very small fraction of total production at the mine). A quick Google search shows the scale of the pit next to the processing facility in the second photo below. The first photo is of us, and although you can't see the pit behind us we are next to the building on the right of the second photo opposite the main processing facility.
To imagine the value of a diamond outside of what you see in jewelry stores, the centre pipe has a grade of about 200 cpht (carats per hundred tonnes), which is actually very very high compared to global averages. Additionally, at times Jwaneng will mine 19 tonnes of waste rock for 1 tonne of kimberlite ore. Doing some quick math, this means they must mine about 10,500 kg of rock in order to recover only one carat of diamonds which is only 0.2 grams!! That’s merely 0.0000019% diamond by weight. It’s no wonder that most employees go their whole life at the mine without seeing a single diamond.
After seeing the pit, we made a quick stop outside the processing facility which recovers nearly 100% of the diamonds found within the ore. At a gold mine, one might expect to see recoveries around 90%, but due to the extremely high value of diamonds a large amount of effort is made to recover each and every diamond. After crushing the ore down to size, the rock is placed in dense liquid which has a specific gravity higher than the kimberlite but lower than diamonds. As a result, the diamonds will sink whereas most of the extraneous rock will float (this is called DMS or Dense Media Separation). At this point, the product is now about 1% diamond. After this, the concentrate is sent to the Completely Automated Recovery Process (CARP) and Fully Integrated Sorting House (FISH). Together, these two buildings are called the “Aquarium” (a degree in mining engineering is apparently a dual major in engineering and pun making). Using x-ray technology, the CARP upgrades the concentrate to 50% diamond by weight which is further increased to 99% diamond by the FISH. Most of the remaining 1% is removed by hand such that 99.9% pure diamond concentrate is sent to the Diamond Sorting Facility that we visited yesterday. The photo below shows the Aquarium from a distance before we went through security.
Lastly, we were hosted for lunch which consisted of very generous and delicious portions of authentic Botswanan food. I would like to thank Debswana and the people at Jwaneng who hosted us today, you truly made this an experience that we will remember for our entire lives!
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