Our operations

Rössing Uranium’s operations consist of two distinct activities: the first is mining uranium-bearing rock, while the second is processing this ore into uranium oxide for the world’s nuclear energy market, which fuels the generation of electricity. Our attention is directed towards creating shareholder value and maintaining a secure and viable business, as well as ensuring that we remain a long-term contributor to Namibia’s economy.

The uranium located in our mining licence area is embedded in very hard and abrasive granitic rock, known as alaskite. To mine the necessary volume of ore and waste, the mine must conduct blasting operations regularly.

Electric and diesel-powered shovels load uranium-bearing rock onto haul trucks, which transport the ore to the primary crushers for the first stage in the crushing process.

From there the crushed ore is conveyed to the coarse ore stockpile, where it is reclaimed and put through additional crushing stages in the Fine Crushing Plant, before the processing stage of operations begins.

 


Our mining fleet uses a combination of electric power and diesel with most of the larger track equipment (drills and shovels) on power. The haul trucks also use a combination of diesel and electricity and are fitted with trolley assist (like an electric tram system) for the permanent ramps that saves fuel and allows them to drive faster uphill while carrying a load. A haul truck takes around 45 minutes to complete a full cycle in the pit from loading at the shovel to returning empty after tipping its 180-tonne load.

MINING OPERATIONS

In 2019, we mined 22.4 million tonnes of rock (13 per cent more than in 2018) of which 8.6 million tonnes was economic uranium-bearing ore (7 per cent more than in 2018), and 13.3 million tonnes were waste and low grade ore (0.5 million tonnes were also dumped in-pit). This equates to a waste-to-ore strip ratio of 1.60, which is slightly lower than 2018, and the waste-to-ore ratio will continue to decrease as the open pit gets deeper.


Despite the higher tonnes mined, the ore milled reduced from 8.9 million tonnes in 2018 to 8.0 million in 2019. The run-of-mine stockpiles ended the year at 1.1 million tonnes.

The uranium grade continued to increase while the calc index started to decrease (9 per cent higher and 7 per cent lower respectively compared with 2018). The better grade largely offset the shortfall in plant throughput relative to 2018.

The higher grade and lower calc index assisted plant controls which saw an increase in overall recovery and decrease in acid consumption.

Grade and calc index remain a key focus in 2020 with the added complication of a high proportion of amphibole schist material that affects processing in the plant. Work continues on controls to improve the consistency of ore blend to the plant. (The calc index is a measure of the acid-consuming gangue minerals in the feed, such as calcite and amphibole.)

Improvements were achieved in a number of other areas, with health and safety at the forefront of many improvement projects at the mine.

On the maintenance side, equipment availability of the drills and shovels improved, while the haul truck availability declined by 3 per cent relative to 2018. Despite this, the planned mined tonnes were achieved for 2019 and 2020 will continue with the same fleet despite slightly lower targets.

Vehicle collision and roll-over with heavy mine equipment(HME) remains the highest safety risk in the open pit. Fatigue management and speed controls will also remain key focus areas in 2020.

Productivity and cost improvement initiatives will continue in 2020, with a specific focus being on the effectiveness of haul truck utilisation, as well as explosives and diesel consumption.

PROCESSING OPERATIONS

The Processing Plant is responsible for the extraction of uranium from mined ore through a number of stages to produce uranium oxide (U3O8). This product is securely packed and shipped to our customers for further conversion.

The aim of the plant is to produce targeted quantities of uranium oxide in the most efficient and safe manner possible.

We produced a total of 2,449 tonnes of uranium oxide in 2019 , which is marginally lower when compared with 2018’s production of 2,479 tonnes.


(From left) Sepo Lusepani (Chemist) and Julia Jason (Laboratory Technician) with test tubes from various stages in our production process analysed in the mine’s chemical laboratory.

 


Rössing Uranium’s young professional employees, Eliaser Silvanus, Hilde Kafidi and Milka Musuuo, at the main entrance to the mine site. The arch in the background was unveiled on 25 July 2019 at the handover of the mine from Rio Tinto to the new majority shareholder, China National Nuclear Corporation (CNNC).

ENGINEERING PROJECTS

Several engineering projects were undertaken during 2019.

Arch at main entrance gate
Shortly after the sale of Rössing’s shareholding was concluded, the engineering team started with the design and manufacturing of the arch gate leading to the mine’s main gate. This arch is testimony of the gateway to a new era, leading Rössing Uranium into a new future.

New solvent tanks in Solvent Extraction area
After a pressure vessel test was done, the existing kerosene storage facility located in Solvent Extraction (SX) was found to be defective. Due to the fact that the SX is a highly flammable and a high-risk area, it was recommended to replace (rather than repair) the old storage vessels. The storage facility was replaced with a 97 m3 facility comprising of two kerosene vessels, with capacities of 67.12 m3 and 30.28 m3 respectively.

A fire detection and suppression system was installed to reduce the risk of fire and, in case of a fire, to contain it. Other improvements made include flow and pressure safety measures for offloading and transfer pumps. Safety mechanisms on the tank levels were also introduced to prevent overflow of the two new vessels. Offloading and transferring can be done to either tanks, or to both, by selecting the relevant valve configuration.

Pulp distributor replacement
During the annual shut-down in the reporting year, the pulp distributor at the first leaching was replaced. In addition, the existing concrete slab was replaced with a fibre-reinforced plastic (FRP) platform while the old pulp distributor was taken out.

The aim of this engineering project was to provide a safe working platform for the operators and also to increase the efficiency of the pulp distributor.

The work included removing the first stage barren distributor and structure, the pulp distributor and all associated pipes. It further involved the replacement of the dilapidated concrete floor with a FRP platform. The new FRP floor is chemical resistant, can take high loads and has a fast assembling process. The platform’s fast assembling process made it possible to complete the project in three weeks.

Leach line repairs
In 2019, Rössing Uranium embarked on a project to repair or replace the concrete trench line located at Leaching Module 1. This trench line passes next to a calcine reactor steel support structure that is seated on concrete bases and stub columns. This area also has a concrete surface bed, which covers the area under the steel support frame and extends to the trench line interface.

The engineering team have noticed structural deterioration on the trench, concrete stub columns and surface bed due to its continued exposure to very acidic slurry spillages from the nearby leach tanks and run off from the rod mills. External consultants completed an investigation on the structural stability and it was decided to reinstate the structures (trench, column bases and surface bed) to be properly protected against the negative effects of future exposure to acidic and other environmental conditions, and perform a functional design period of minimum ten years.

Repairs on Primary Crushing structure
Critical structural repair work was embarked upon to the Primary Crushing structure, retaining walls and support members. Most notably to the hopper floors, where innovative engineering resulted in making use of old railway lines to prevent future damage to the hopper floors.

The crushers were shut-down twice to permit structural repairs to both hopper floors, which were successfully repaired in October.

Arandis roofing project
In 2018, the Arandis Town Council, in collaboration with Rössing Uranium and the Rössing Foundation, started a project to remove the asbestos roofing sheets from 416 houses and two primary and secondary schools in the town, replacing these with zinc-aluminium roofing sheets that are environmentally friendly.

This followed engagement with the residents through public meetings and awareness campaigns about the possible health risks of using asbestos roof sheets.

During 2019, a total of 239 houses’ asbestos fibre cement roofs have successfully been removed and replaced, totalling 65,900 m2. The project experienced delays during June to August due to excessive wind speeds, preventing the removal and replacement of the roof sheets.

Community co-operation with the process continues to be excellent. At the beginning of the year, it was planned that the roofs of 320 houses and the schools would be completed by December 2019. However, due to proper cost control, the project will be able to complete 436 houses at the end of April 2020 within the budget of N$28 million. This means that all critical and high-risk house roofs will be completed. All asbestos sheets removed are disposed of at the Walvis Bay hazardous waste site that was upgraded to accept all the material from the project.

Other engineering projects
The following were other engineering projects completed during 2019:

  • To mitigate or eliminate exposure to fire risk, fire retardant coating was applied to all cables and trenches in all major substations, while the fire detection systems in all major substations were upgraded or extended, and integrated into the early warning alarm system at the Protection Services control room.
  • Dust ingress mitigation: pressurisation units were installed at seven identified high potential dust contamination medium voltage substations and at the motor control centre feeding the reduction area.
  • Medium voltage (MV) switchgear refurbishment: A new modular MV switchgear was installed and successfully commissioned at the Administration offices and Protection Services building to render redundancy capability of supply to these premises and upgrade obsolete switchgear, which served the reticulation system for more than 40 years. (Redundancy capacity refers to the inclusion of extra components which are not strictly necessary to function, but used in case of failure of main components.)
  • Energy meter extension: The installed consumption metering system was extended with the installation of a further 13 energy meters to enable complete energy consumption monitoring and verification to all billing areas within the mine.

FRUITFUL COLLABORATION BETWEEN CNUC AND Rössing TEAMS

With the change in majority shareholding, collaboration between Rössing and CNUC opens up avenues of efficiencies in the sharing of new knowledge, skills and technology.

One such example is the trialling of ‘down-the-hole’ (DTH) logging technology in the open pit. DTH logging, as applied at Rössing, is a process whereby U3O8 grade is determined by collecting radiometric data down blastholes with the use of wireline technology.

This removes the error associated with the current practice of collecting physical samples from the cone of drill chippings surrounding each hole.

DTH logging trials were first conducted at Rössing in 2017 using an external contractor and again in 2019 with support from CNUC. Both trials focused only on the determination of U3O8 grade using similar technology, but the CNUC trial was more automated, using vehicle mounted tools.

Results from both trials confirmed the ability of DTH logging to provide U3O8 grade information.

In addition to better grade information per hole, another clear advantage demonstrated during the CNUC trial was the ability to obtain 3D grade data with depth and across the drill pattern. This has the potential to improve resource estimation and mining selectivity.

In addition to better grade information per hole, another clear advantage demonstrated during the CNUC trial was the ability to obtain 3D grade data with depth and across the drill pattern. This has the potential to improve resource estimation and mining selectivity.

Benefits demonstrated during the CNUC trial can be summarised as follows:

  • Improved data quality and collection;
  • Reduced HSE exposure (ergonomics, auger vibration, dust and heat exposure);
  • Faster turn-around-time leading to better decision making;
  • 3D information with the potential for better resource estimation; and
  • Potential reduction in operating cost through less labour intensive process.


(Above) Faustina Shuuya (Senior Assistant Geological) using the ‘down-the-hole’ (DTH) logging technology at blast holes in the open pit to collect radiometric data down the holes with the use of wireline technology.

PROCESS SAFETY MANAGEMENT

Process safety management (PSM) is a systematic approach of controlling the unwanted release of hazardous substances, process solutions or fires and explosions that have the potential to significantly impact the health and safety of employees, the environment or the business.

In 2019, Rössing Uranium’s PSM steering committee decided on four main process safety hazards. These four process safety hazards are managed with strict engineering and administrative control strategies. The four hazards identified were:

  • anhydrous ammonia gas,
  • concentrated sulphuric acid,
  • fire in the solvent extraction and final product recovery plant, and
  • engulfment due to large processing tank failures.

Formal internal and external audits were conducted in April 2019 to assess how efficient the mine is at controlling process safety hazards. The audit findings justified a ‘deep-dive’ hazard and operability study on anhydrous ammonia storage and distribution systems. These systems have been upgraded to prevent any loss of containment and also improve detection of any leaks.

The PSM team received formal training to enable them to train operational leaders on mindfulness of process safety and how to manage it by using control strategies. The main objective of this training was to obtain a deeper understanding of process safety management and sensitise operational leaders to the realities of process safety incidents. All operational leaders at Rössing Uranium received training in May 2019.

In the latter part of 2019, it was identified that the engineering standards and manuals currently being used are outdated. The PSM team was tasked to identify the shortcomings and embark upon updating of these standards and manuals as an improvement project in 2020, together with the normal day-to-day control strategies of the mine’s four main process safety hazards.

In the beginning of 2020, the next PSM system audits will be done, in addition to a ‘deep-dive’ hazard and operability study to be conducted on the sulphuric acid storage and distribution systems.

The PSM team will persist in their supportive responsibility towards operations, maintenance, engineering and HSE.

INFORMATION TECHNOLOGY

A highlight was being nominated for the SAP Africa Quality Awards. (SAP stands for Systems Applications and Products and is a business application software program.) At the gala event held in Johanneburg in August, recognising some of Africa’s most innovative public and private sector SAP customers, Rössing Uranium was awarded a bronze award in the Business Transformation category.

The implementation of the stand-alone SAP enterprise resource planning (ERP) software system was completed in April 2019, to enable Rössing Uranium to function independently.

Significant upgrades have been made to improve the wireless networks around conference rooms and offices for both employees and guests visiting the mine. Additional fibre network was installed in the open pit to reduce the current highly congested wireless networks.

More surveillance cameras were added around the administration buildings and parking areas on the mine to improve security. In addition, 58 cameras were fixed in 2019 as part of the surveillance cameras remedy project.

Looking forward, a key project which will be implemented in 2020, is the SAP Time and Attendance Project or Workforce Management solution on the SAP system. The key benefits of this system will be labour-cost reduction through controlling overtime and effective time, absenteeism management, productivity and services improvement and the mitigating of compliance risks.

All documents from the HR and HSE departments have been migrated to a document management system called SharePoint. All other remaining departments will also be migrated to the same system over time. Key business requests forms are also converted to electronic format, with an electronic approval workflow process. This will significantly reduce paper forms and the need for people to run around to get paper-based approvals.

The surveillance cameras remedy project will continue in 2020. An investigation will be done early in the year to ensure all 205 cameras are fully operational.


Milka Musuuo (HSE Training Advisor), Regina Nambahu (OHSE Representative) and Hilde Kafidi (Health and Wellness Advisor), conducting a critical risk assessment (CRM) at the Fine Crushing area in the Processing Plant. For Rössing Uranium, safety is the foundation on which we build our business and our surrounding community. We believe all incidents, injuries and occupational illnesses are preventable and, therefore, our goal is zero harm.