We worked literally alongside the MRL (Mineral Resources) team using our “Engineers On Tap” (EoT) service model to provide instant access and response throughout this project.
Project Background
Starting in January 2018, we started working on the upgrading Wodgina Lithium Project with our client Mineral Resources (MRL).
The open-pit Wodgina Lithium Project in the Pilbara region of Western Australia is the biggest hard rock deposit in the world. The project is estimated to have a mine life of 30 years.
Mineral Resources (MRL) acquired the mine from Global Advanced Metals in September 2016 and started mining operations in February 2017. The first shipment of 113,993 wet metric tonnes of lithium direct shipping ore (DSO) from Wodgina was made in April 2017 from Port Hedland to China.
MRL exported 3.4 Mt of lithium DSO in 2018 and expects to produce 5.5 Mt in 2019.
MRL is currently expanding the Wodgina project to increase spodumene production and develop an integrated lithium hydroxide operation at the resource site.
Construction of a new 750,000 tpa spodumene concentrate plant commenced in March 2018, and commissioned around six months ago.
Challenges
One of the biggest challenges we faced was designing the secondary crusher building to also support a retaining wall almost 20 m high.
Conventionally, the steel structure is independent of the ROM wall.
Our client wanted to save money and time by combining the two, so that became the challenge for us as the structural engineering team. The structure struggled with excessive soil pressure in both directions.
The biggest issue we had during the design stage was how to transfer the earth pressure to the foundation
The design was revised a few times, beginning with stiffened steel panels before settling on a concrete retaining wall. In the end, we designed shear walls within the structure to support the retaining wall and transfer the massive forces through bolts into the raft footing below.
It was a big challenge but ended with a positive outcome. The construction was completed in late 2018 and we are proud to see the structure we designed serving its purpose.
Stockpile Design
Designing a 28m high stockpile cover with a diameter of 90m in wind region C was challenging too.
The Yenem team designed the stockpile cover to withstand both high external and internal wind pressure with Microstran. We also provided a construction methodology of the stockpile cover.
The structural members were bolted as panel frames in the workshop before delivering to the site to save on-site cost. Temporary props were designed and proposed by Yenem to make sure the stockpile cover was being constructed safely.
Summary
It was a big challenge but ended with a positive outcome. The construction was completed in late 2018 and we are proud to see the structure we designed serving its purpose.
The success of this structure and the project as a whole was in the collaboration between the whole team – project, design and construction
people at MRL alongside all of us at Yenem.
The Yenem team is always passionate about solving dicult problems for our clients. We provide the most economical and constructible designs that meet project requirements because we work together with all stakeholders given the opportunity.
