Phase 4 pre-feasibility study update
The Phase 4 mining pushback is the lowest costexpansion option available to Rössing Uranium and will benefit from leveraging off the existing processing and infrastructure facilities.
The mine conducted a Pre-Feasibility Study (PFS) in 2015/16 on the development of Phase 4, which indicated the potential to extend the life-of-mine (LOM) by six years, from 2025 to 2031 at a mill throughput rate of 12 Mtpa to recover an additional 18,000 tonnes U3O8. This proved value destructive and the project was deferred to allow the market to recover to the project break-even uranium price of USD60/lb.
Following the 2019 sale of Rio Tinto’s majority shareholding in Rössing to China National Uranium Corporation (CNUC), who have an interest in a longer supply of uranium from Rössing, an updated options review of Phase 4 was carried out that built on the work done in the PFS, as well as a care and maintenance study done in 2017/18.
By introducing new macro-economic parameters (exchange rate, inflation, long-term prices, among others), and adjusting pit shells, haul truck design, and start time, a total of 19 different mining options have been compared and studied. Some options can achieve a lower stripping ratio and generate positive net present value. A pre-feasibility study and a feasibility study will be conducted from 2021 to 2023.
The conclusion is highly sensitive to macro-economic parameters, and a decision to mine Phase 4 could therefore be made at a later stage (to be re-assessed in 2023), which would also allow more relevant and up-to-date macro-economic parameters to be considered in the evaluation.
New CIX and SX Plants pre-feasibility study
The current Continuous Ion Exchange (CIX) and Solvent Extraction (SX) plants at Rössing Uranium have been in operation for nearly 45 years. Due to the inevitable long-term aging effects and accelerated and enhanced wear and tear on the plant infrastructure, as well as the unavoidable effects of the prolonged exposure to highly corrosive acidic and alkaline process solutions, some of the civil structures, storage and containment process vessels and concrete floors are increasingly failing at a higher rate.
In view of the current studies to extend the life of the mine to 2035, this has prompted the need to consider investigating opportunities to upgrade the CIX and SX plants to ensure that the infrastructure in the Processing Plant areas will be in a condition to sustain safe, efficient, and effective operations for the next 15 years and beyond.
To this end, the mine requested CNUC’s technical team to undertake a preliminary feasibility study to upgrade the CIX and SX plants at Rössing. This work is intended to cover aspects pertaining to engineering designs for the equipment required in the two plants, as well as the installation and integration of the new equipment into the rest of the Processing Plant.
This study is intended to investigate the different options for upgrading the ion exchange (IX) and SX processes to bring about continuous improvement aspects during the operation and maintenance of these purification plants for the remainder of the life of mine. The study should ensure that the purification plants are designed, engineered, operated, and maintained in a way that ensures the safety and health of all employees and stakeholders, as well as protecting the environment. The study is intended to investigate and evaluate the different options of the IX and SX processes and technologies for the current and the potential extended life-of-mine.
This study is still in progress and is expected to be completed in the first half of 2021.
TSF footprint extension study
The current Tailings Storage Facility (TSF) at Rössing Uranium does not have capacity to accommodate life-of-mine expansion beyond 2026. Design engineering firm, Knight Piésold, was contracted to evaluate the available capacity of the TSF under the current footprint.
It was established and confirmed that the TSF will reach its capacity (end of deposition) by 2027. An additional 93Mt is required for the life-of-mine expansion to 2035.
A further study was undertaken by Knight Piésold, with the involvement of Rössing, to consider the options available in terms of expanding the current TSF. Nine options were considered in the assessment for potential tailings deposition sites.
This study is still in progress, and the pre-feasibility study will be completed in 2021.
In 2020 primary focus was placed on the implementation of the SAP Time and Attendance system. Rössing Uranium had a requirement to implement a SAP Time Management solution whereby employee and contractor work attendance is captured via an external clocking system into SAP. This will enable line managers to greatly improve the management and control of employee and contractor working time.
Rössing Uranium has been using the SAP S4Hana since April 2019. Currently time payment data is manually advised from time sheets with only the SAP modules of Leave Management, Payroll, Personnel Administration and Organisational Management being used.
Primarily, the implementation of the SAP Time Management module supports businesses in paying employees according to the exact number of hours worked. SAP’s “Combination Method of Time recording” will be used where an employee’s basic salary is guaranteed and is only affected by approved overtime and unpaid absences. The enhanced control of overtime fraud, incorrect capture and overpayments will lead to significant financial savings.
The solution also provides the tools to control excessive work hours and assist in complying with legislation in respect of allowable maximum working hours and non-compliance to the company fatigue management policies. In this regard, the project will provide significant efficiency improvement, which eliminates chances of legislators taking the company to court for failing to comply with prescribed laws, translating into financial savings, increased productivity and improved safety compliance.
Other completed projects that made a significant impact on the ability to communicate and expanded existing systems, included:
- Improved communication through the installation of 42-inch TV monitors around the mine with media player capabilities which enable Rössing to present informative videos on COVID-19 and interesting news to employees throughout the mine, while
- Fibre expansion through the plant area opens new opportunities for more systems requiring wireless or wired network connections.
From the information that is now visible from the SAP Time and Attendance system, business process improvements can be identified to reduce labour costs, improve productivity through better resource planning and absenteeism management, while simultaneously mitigating compliance risks from fatigue management.
Looking ahead, focus will also be placed on improving the CCTV surveillance coverage by the installation and upgrading of the CCTV surveillance system.