There are several factors that must be considered when selecting screening equipment for a mining operation.
Choosing the right screening equipment is essential for mining operations looking to optimise efficiency, enhance material quality, and meet production targets.
Screening equipment isn’t a one-size-fits-all solution; every operation has unique requirements, and understanding these needs is critical to selecting the most suitable machine.
Asking the right questions can help ensure the equipment meets operational demands and delivers long-term value.
Here are eight key factors to consider when selecting and sizing screening equipment.
Throughput requirement
The cornerstone of equipment selection is understanding the volume of material to be processed, typically measured in tonnes per hour (tph). Manufacturers rely on this figure to recommend appropriately sized equipment.
Matching the equipment to the operation’s capacity ensures efficiency and minimises downtime. Overestimating or underestimating throughput can lead to unnecessary wear or underperformance.
Particle size distribution
A detailed particle size distribution is fundamental to selecting the right screening equipment as it defines the size range of materials that need to be separated.
This data includes the proportions of particles above, below, and near the desired cut point, as well as the maximum particle size in the feed stream.
Supplying accurate information ensures manufacturers can recommend equipment that meets the specific needs of the application, addressing not only the required separation but also factors like operational variability.
Providing details on oversize and half-size particles relative to the cut point is especially beneficial as it gives a more comprehensive view of the feed material. This allows manufacturers to optimise equipment design and ensure consistent performance, delivering a solution tailored to the operation’s requirements.
Bulk density of material
Understanding material density allows manufacturers to account for factors like material flow characteristics and wear on the equipment, ensuring the machine is robust enough to withstand operational demands.
This information is essential to designing a solution that delivers reliable performance and long-term value under real-world conditions.
Moisture level of feed material
Moisture content is a key factor in screening performance, particularly for finer particles. High moisture levels can affect material flow and screening efficiency, causing clogging or sticking that can disrupt operations.
Understanding the moisture content of the feed material allows manufacturers to account for these variables when recommending equipment, ensuring optimal performance and consistent throughput.
What cut points are required
Whether the goal is a single separation or multiple, understanding cut point requirements is essential.
Some operations may require straightforward separations, while others require more complex configurations to meet their production goals.
Equipment such as vibrating screens and rotary trommels can be designed to accommodate various cut points, ensuring precise particle size separations tailored to specific needs.
Providing clear information on the desired separations allows manufacturers to recommend equipment that delivers accurate and efficient results, regardless of the application’s complexity.
Screening efficiency
No screening device is 100 per cent efficient, but understanding the acceptable level of efficiency for a given application is critical. Pre-crusher screens, for example, may prioritise throughput over precision, while classifying screens for finished products demand higher efficiency.
There’s a world of difference between 80 per cent and 95 per cent efficiency, so it’s important to ensure the right balance of performance and cost.
Any special requirements?
Certain additional features can be crucial in meeting specific operational needs and improving screening efficiency.
For example, water spray systems can be used to wash material for a cleaner separation, while specialised drive mechanisms enhance performance and help minimise wear.
Other options, such as screen heating and ball tray decks, can further support the production of cleaner products.
Communicating these requirements allows manufacturers to recommend the most appropriate equipment tailored to your operational goals and challenges.
Screen media
The choice of screen media – whether steel wire, polyurethane, rubber, or other options – has a significant impact on the screening process.
Different media types influence the open area, which can affect the size of the screening unit. It can also affect the number of decks on a vibrating unit or the diameter and length of a trommel.
Previous experiences with specific media types may inform your preference, but consulting with a manufacturer can help ensure the most effective choice for your application.
A collaborative approach
Partnering with an experienced manufacturer is important when selecting screening equipment. McLanahan, for example, brings 190 years of experience designing and manufacturing screening solutions for mining operations worldwide.
Even if you’re not an expert, a trusted manufacturer can guide you, and by answering these eight questions, you equip them with the insights needed to recommend the best solution for your application.
As mining operations continue to seek greater efficiencies, investing time in understanding screening needs upfront can yield significant long-term benefits.
This feature appeared in the February 2024 issue of Australian Mining.
