Reuse, Refurbish or Replace? How to select the right option for your plant expansion

16 August, 2021 | Blog

Catherine Pelletier, P.Eng.

Engineer, Metallurgist

icon linkedin

Thinking of increasing your plant’s capacity, modifying your flowsheet or upgrading your equipment? It may be tempting to raze your existing plant to the ground and start with a clean slate, especially if you’ve had a hard time operating or maintaining it. But before you bring in the bulldozers, take a moment to evaluate your assets’ condition and perform a gap analysis against your expansion requirements.

Deciding which equipment is worth keeping or modifying is not always obvious. In these cases, a formal trade-off study can be helpful to refine and solidify thoughts and make an impartial decision. Trade-off studies typically involve identifying several potential solutions and methodically comparing them using pre-determined selection criteria.

Here are four principles to keep in mind to ensure the best outcome for your trade-off study:

1. Get the facts

The outcome of a trade-off study is only as good as the quality of the information it’s based on. Gathering and analyzing the right information is critical to avoid missed opportunities and make the best decision for your organization.

Your trade-off study process will need to start with a field evaluation of the equipment’s current capacity and condition. This field evaluation should extend to the equipment’s support structure, electrical infrastructure and associated instrumentation. Having to replace or modify any one of these components can be costly, so their current condition and capacity should also be part of the equation.

To flesh out any modification or refurbishment scenario, it’s important to gather all information regarding the type, amount and cost of work involved. It’s also important to understand the scope of work required. Forgetting to include one aspect of the work required in your study can change the outcome of your comparison, leading you to believe you’re selecting the most cost-effective option, while in reality, you’d be selecting the least complete option. Take the time to understand the logistics of the work required and reach out to professionals who have done this type of work before. They’ll point out steps and aspects of the work you may have overlooked and even provide alternative solutions you hadn’t thought of. Only then can you ensure that all aspects of the work are factored into your evaluation.

When evaluating the cost of purchasing new equipment, remember to factor in installation costs. In a retrofit situation, existing installations may require demolition or extensive structural modifications, which can significantly increase cost. When in doubt, 3D-modelling of the existing space is the surest way to visualize how new equipment would interface with existing installations and determine the extent of the work required for the retrofit.

2. Make the most of what you have

Of course, any existing equipment you can reuse is something you won’t need to purchase. If certain components of your existing equipment are deemed to be in good condition, identifying scenarios where these can be reused may lead to savings. Remember that this doesn’t have to be an all or nothing situation!

3. Don’t box yourself in

Make sure your equipment’s configuration makes sense for your application. Start by establishing constraints and use them to guide rather than limit the generation of new solutions. For the results of your trade-off study to be valuable, these constraints must align with your organization’s vision and strategy to avoid spending time developing solutions that will be immediately rejected or ignored. With these constraints in mind, use a double-diamond approach (or similar design process) to explore various alternatives at a high level before identifying which solutions should be further developed and detailed. A little bit of creativity at the start of the process goes a long way when identifying alternative solutions.

4. Get the right team

With so many aspects to take into consideration, working with a multidisciplinary team is critical to preventing the project from being viewed from only one angle. Working with team members focused on very different perspectives fosters creativity, which generates ideas that can lead to innovative solutions. Whether you assemble this team internally or reach out to external experts, surround yourself with people who have the right expertise to speed up the process. Their insight can help you prevent costly mistakes.

Our team in action

Here’s a recent example of how one of BBA’s multidisciplinary teams worked to determine whether existing flotation cells should be refurbished or replaced as part of the client’s upcoming plant expansion. The initial plans included the refurbishment of 30 Denver-type flotation cells to limit capital investment for their project. BBA was mandated to assess the existing equipment’s condition, prepare a refurbishment plan and determine whether the existing cells should be replaced.

The first phase of the mandate was to define the refurbishment option. A team of field engineers was deployed to the site to assess the cells and their auxiliary equipment condition. The inspection revealed that cells were in rough shape, several of them needing new agitators and significant tank repairs.

The existing facility was scanned to identify major structural components and build a 3D model of the plant. Using the 3D model, BBA’s mechanical and process engineers were able to model new cell configurations proposed by vendors. Initially, the vendors proposed the most common tank cell technology. However, placing the proposed cells in the 3D model revealed that this technology was inadequate due to height limitations and differences in cell support configuration. So, the team suggested the client consider an older U-shaped cell technology, since their shape and configuration were more similar to the existing cells. With this option, existing civil works could be reused, allowing for significant installation savings. BBA’s process team then validated that the U-shaped cell would meet the required performance targets, allowing this option to be included in the trade-off study.

Cost comparison of the two options indicated that replacing the existing cells would cost approximately $700,000 more than refurbishing them. However, the new cell option would require fewer cells equipped with more efficient agitators, resulting in energy savings in the order of $450,000 per year. This option would also come with a performance guarantee, limit the amount of transfer pumps required and liberate significant footprint in the existing building. With this information in hand, the client was confident that replacing the existing cells was the better path forward for the long-term and adjusted their expansion plan accordingly.

This project is an example of how we can help you make informed decisions for your expansion projects. Feel free to contact our experts to plan an upgrade of your installations.

DO YOU HAVE A SIMILAR CHALLENGE?