A number of factors influence the on-site productivity of bulk materials handling operations at mineral processing plants. An element that plays a great role in providing a clean, safe and productive environment is the design of transfer points. Traditionally, conveyor systems design focused more on the structural integrity of the system and the selection of the mechanical components. Unfortunately, the design of the transfer points was considered of secondary importance and was constrained by a lack of design analysis of the material flow characteristics and needs.
Poor design and implementation of transfer points can result in increased maintenance costs for minerals processing systems. “In essence, mineral processing plants need a system that is upgradeable and cost effective, that will improve accessibility and serviceability, decrease downtime and conveyor belt wear, and that conforms to SHEQ (safety, health, environmental and quality) regulations,” says Mark Baller, Managing Director of Weba Chute Systems.
Ballers points out that the issue at hand is the uncontrolled discharge of bulk materials through conventional chutes. Using information gathered from flow studies, on-site investigations and extensive operational experience, the Weba Chute Systems team tackled the problem and devised a solution that would optimise material flow in the direction of travel.
The main thrust of the research and subsequent design of the Weba Chute System ‘supertube’ effect with a cascade scenario is to minimise the impact on both the chute and the conveyor belt. “We investigated the optimal way of ensuring that the material is evenly and centrally loaded onto the conveyor belt. With the Weba Chute System, up to 95% of the material runs on material at all times. The bottom layer of particles in the product stream moves in a tumbling motion rather than sliding down the chute,” Baller explains.
The design was achieved using a sophisticated 3D Computer Aided Design (CAD) program. It has resulted in significantly reduced wear, less spillage and enhanced SHEQ compliance.
Productivity is also influenced by two other salient factors – the ability to fit-to-purpose and the after-sales service that a chute manufacturer provides. Weba Chute Systems approaches each project in an individualised manner. “The process begins with a thorough site visit where the Weba Chute Systems ascertains the exact requirements of the customer through interviews with their operational and engineering teams. Thereafter, the optimum design is created and tested using a combination of sound engineering tools, substantial practical knowledge and Discrete Element Method (DEM) simulation as a verification tool,” Baller explains.
“It is important to factor in the operation’s unique product specifications and data, belt width, belt speed, material sizes and shape, and throughput as well as the plant layout, including the position of belt scrapers and dust suppression/extraction systems. We take a holistic approach towards chute design, which encapsulates both the entry and exit points, as well as the control of the flow, volume and velocity of the material being transferred at all times,” Baller continues. The company is so confident of its design methodology that it offers the end user a performance warranty.
Weba Chute Systems believes in accommodating the customer’s project schedule and will pull out all stops to ensure that deadlines are timeously met, without compromising quality. “By working closely with the customer’s team we are able to rapidly address and resolve any issues. Our support team is trained to instantly assess and alleviate unforeseen spillages, high wear and blockages through consultation with our chief designer and engineering department,” says Baller.
The interaction and involvement with the installation and customer does not end when the project is commissioned. Weba Chute Systems remains involved with the customer and encourages ongoing proactive and planned maintenance checks. By identifying and resolving any possible issues in a pre-emptive manner, downtime is eliminated and productivity is increased.
In yet another instance of proactively searching for solutions that will add benefits for its customers, the company has also developed an innovative quick release cast modular chute lip system. “The quick release cast chute lip will result in a much faster change out period for mine personnel, resulting in higher productivity levels,” Baller concludes.
