Angula Kalili: mining’s in his blood

2019-02-19T11:30:45+00:00 February 19th, 2019|In the stope|

The Husab Mine, close to Swakopmund in Namibia, is one of the top uranium producers in the world. Leon Louw chatted to Angula Kalili, the chief operating officer at Swakop Uranium, to learn more about this mine.

Angula Kalili, chief operating

Angula Kalili, chief operating officer at Swakop Uranium. Image credit: Leon Louw

Angula, you were born and bred in Namibia; how did your mining journey start?

I went to primary school in Oranjemund, a small mining town in the south of Namibia. Oranjemund is a diamond operation partially owned by De Beers and the Namibian government (Namdeb). Because there was no high school in Oranjemund, I had to move to Windhoek, the capital of Namibia, where I attended Concordia High School.

After high school, I enrolled for a Bachelor of Science degree at the University of Namibia, but in my second year, I decided to study mining engineering instead and moved to Johannesburg to attend Wits University, where I graduated in 2000. After university, I joined AngloGold’s (today AngloGold Ashanti) Navachab gold mine in Namibia, moved to the company’s Geita gold mine in Tanzania five years later, and after two years, I moved to Mali to work at Sadiola.

Two years later, I was back in Namibia when Areva (today Orano Mining) began to develop the Trekkopje uranium mine close to Swakopmund. When the project was put on care and maintenance because of the low uranium price, I moved back to Navachab, then did another four-year stint at Geita, before returning to Namibia to take up the position of chief operating officer at Swakop Uranium’s Husab uranium project.

And the owners of Husab are Chinese?

Husab is owned by Swakop Uranium which, in turn, has two major shareholders, namely the Namibian government-owned Epangelo Mining, which holds 10%, while a Hong Kong-listed company, Taurus Minerals, owns the other 90%. Sixty per cent of Taurus Minerals is owned by China General Nuclear Power Group (CGN) and 40% by the China Development Fund.

How different is uranium mining compared to gold mining?

The mining side of the operation and the mining methods are the same: Defining the ore body through grade control, depending on the level of selectivity, delineating the ore and the waste and then mining, which entails traditional drilling and blasting, developing the benches based on the type of equipment, and load and haul to the ore stockpiles at the crusher or waste dumps.

Were all the previous mines you managed opencast mines?

Yes, they were all opencast mines; however, at Geita, we managed to open two underground mines as part of AngloGold Ashanti’s growth strategy. Geita has now actually transitioned into underground mining, and most of their ore is now sourced from underground operations.

The uranium price has been in the doldrums, with many uranium mines in Namibia struggling to keep head above water; yet, Husab is expanding. How did the mine manage to do that? 

The general environment is difficult at the moment and most other mines are scaling down or going on care and maintenance. In contrast, Husab is on a growth trajectory. The reason, of course, is that the main shareholder actually consumes the product, so that’s a big advantage. Husab has an offtake shareholder that is a nuclear generation company.

Am I right in saying that Husab now produces the most uranium in Namibia?

Yes, that’s right. Furthermore, the mine is still ramping up. By the end of 2018 [when this article was written], we forecast to produce half of our net capacity, so we are in the region of about 3 000 tons (t) U3O8 (uranium oxide), which is what we package as final product for further processing.

How much will you be producing at full design capacity?

In 2018, we expect to produce between 3 000 and 3 500 tons, eventually ramping up our nameplate capacity, which is close to 6000 tonnes per annum (tpa).

When will nameplate capacity be reached?

Projections are that we will reach nameplate capacity towards the end of 2019 into 2020. Currently we are still optimising and addressing some of the bottlenecks we have identified in the plant design.

When did the mine start producing uranium?

The first uranium was produced on 31 December 2016, more than two years ago.

How many workers were involved in the construction of Husab?

In the construction stage, we employed more than 5 000 people. But we have obviously moved into operational stage, so currently, Swakop Uranium has 1 600 permanent staff on their payroll, and we also use an additional 500 or so contractors. With 2 100 people working on the mine, Swakop Uranium can be regarded as the single biggest employer in the Namibian mining industry.

What is significant about this mine?

The mine is the biggest employer in the Namibian mining industry. Its contribution to the Namibian economy in terms of taxes, social investment, and skills development is substantial. Small and medium-sized enterprises are benefiting, and the mine is a significant contributor to the country’s GDP. On a global scale, in terms of the size of the operation and considering both the current and forecasted production, Husab can rightly be regarded as one of the biggest producers in the world.

How does a massive mine like Husab keep the wheels turning in an extremely difficult economic environment? 

My motto in mining is efficiency. The only factor you can control, and manage, is efficiency. It is only after you fail in being efficient that you can say: well, let’s close the mine. So, in our strategy, there is a big focus on cost efficiencies.

What is the life of mine?

We are currently planning around a 20-year life of mine and at the same time, we are also continuing with exploration work on two Exploration & Prospecting Licences (EPLs) close to our current licence. Uranium, however, is different from gold, for which there is a spot price on the international markets. Uranium mines, in many cases, enter into medium- to long-term contracts on a guaranteed price, so even if the price fluctuates, it doesn’t really matter.

How many mineralised zones are you targeting?

We have five potential mineralised zones on the property, of which we are currently exploiting two zones: Zone 1 and Zone 2. Both are mined through two opencast operations very close to each other.

In this area, there are six different formations: the Kalahari forms the overburden, below the Kalahari is the Khan and then Chuos, followed by the Rossing, Karibib, and the intrusive layers, which occur a lot deeper. The ore is concentrated around the Rossing formation. The ore doesn’t seem to occur in any of the formations below the Rossing formation. Our two open pits have now reached depths of close to 90m and 140m, respectively.

Which mining methods do you use in the two pits?

Both sites are opencast operations. We use a conventional truck and shovel method to mine the ore body with hydraulic and electric shovels. The mining fleet consists of six shovels that include three CAT 6060 face shovels and three CAT 7495 electric shovels. In total, we have 26 trucks of which 23 are the Komatsu 960 E, and three are the NTE 330, which is a Chinese-manufactured truck. There are 12 drill rigs in the pit, and here we also have a combination of diesel and electric rigs: there are three CAT MD6640 electric drill rigs and four CAT MD6290 diesel-driven drill rigs. In addition, we operate one CAT MD 6650 and four Atlas Copco Rock L8s. The Rock L8 is mostly for smaller-diameter holes for pre-strip drilling. Our hole diameter varies between 127mm for the smaller pre-split holes and 331mm for waste drilling. The ore drilling diameter is 251mm.

Extra axillary equipment (mostly Komatsu) include a total of six dozers (three Komatsu 475s and three Komatsu 375s), four wheel loaders, also Komatsu (WD600), plus three Komatsu 825 graders and four PC850s for clean-up work and digging trenches. We also have additional support equipment to move the electric cables and infrastructure.

The entire fleet is designed to move between 100 million and 120 million tonnes per year. Our production profile currently for this year is to move 100 million tonnes with a complement of just under 490 people. Given the size of the equipment and the distances covered, our fleet is installed with a Modular Fleet management system that manages, monitors and controls, and ensures efficiencies of our fleet.

Will the mine continue ramping up in the next two to three years?

We are currently targeting 10 million tonnes per year of ore in the short term, ramping up to 15 million tons of ore over the next three years. On average, the life of mine feed to the processing plant is 15 million tons per annum (currently it is 10 million per year). The feed grade ranges between 500 and 600 parts per million (ppm) over the life of mine.

Can you tell us more about the processing plant?

We have five main facilities: the primary crusher; the milling circuit; the leaching unit; the counter current decantation (CCD) and the ion and sulphate exchange; and then the final processing and recovery area.

The ore is dumped by the mining team into a gyratory crusher (4 000 tonnes per hour). The crushed material is then fed onto a course stockpile via an overland conveyor onto a covered coarse ore stockpile with a capacity of 190 000 tonnes. It is then reclaimed through reclaim feeders into a semi-autogenous grinding (SAG) mill before transferring into a ball mill. From the ball mill, the undersize reports to six screens, which then separates the material into the correct size distribution for the leaching stage. The undersize reports to the leaching circuit, while the oversize is fed back to the ball mill.

Up to that point, the aim is to reduce the size of the material that is small enough to liberate all the uranium, between 0.6mm and 0.8mm. In the leach area, there are 10 leach tanks in which the slurry is mechanically agitated with blades. In the tanks, we add acid and other chemicals to the slurry to dissolve the uranium.

The slurry is passed on to the CCD, which is the sequence in which the material is fed from the leaching tank versus settling; in other words, a solid liquid separating process. The solids which now contain very little uranium, settle at the bottom and are then pumped out to the tailings dam.

The solution is then passed on for clarification where impurities are eliminated. From there, it is fed to the ion exchange. The chemical reaction that takes place during this stage results in the uranium that is in the solution being attracted onto resin, and then, through a series of chemical reactions, that solution is concentrated. This solution is then passed on to the final product area where it is precipitated into uranium and then packaged as a final product through a fully automated packaging process.

Because of the high radiation, the packaging is done in a fully enclosed environment where the product is drummed and sealed in containers, which is taken directly, by road, to the Port of Walvis Bay.

Where does the mine get its water from?

Our water is provided by the government entity NamWater; however, they source most of the water from the desalination plant built by Orano (previously Areva). The plant was originally built to provide the Trekkopje uranium mine with enough water.

Do you not regard it as a risk to be relying on water that could one day be used by Trekkopje if the mine re-opens?

It is a risk. If Trekkopje decides to commence with its mining operations, we will have a water supply challenge. The quantity of water that we require, currently only they can supply; we don’t have enough capacity from local sources. So yes, it is a significant risk for us. We are, however, working at mitigating that risk. NamWater has the same problem.

There will be a serious problem if all the uranium mines in this area start operating at full capacity and all need water. Uranium mining is water intensive and to source enough water in a desert environment is problematic. We use about 0.6 cubic metres per tonne. This is all part of the risk that we need to evaluate and assess.

Should the mines and the authorities not start thinking about more desalination plants?

There are discussions about more desalination plants.

And the electricity supply?

We get our electricity through the national grid from NamPower and do not experience any problems, but we also generate our own electricity on site. The mine has its own acid manufacturing plant and we use the steam generated by the process to drive a turbine that produces about 15MW capacity. In addition, we have nine 10MW installed diesel generators. The diesel is only for emergencies, though.

What maintenance regime does the mine follow?

We do our own maintenance, with the support of the original equipment manufacturers like Barloworld (CAT), Komatsu, and Atlas Copco. Our in-house team looks after the processing plant, maintenance, and our mining maintenance. There are several workshops on the mine site, including a workshop for drill rigs and trucks as well as auxiliary equipment. There is also an electric workshop, a boiler workshop to attend to all the mining equipment, and then likewise, in the processing plant, we also have communition, slurry, and electrical workshops to support the plant.