Headed by Henk Brink, Cedotech models transfer chutes, the point of transferring bulk materials flowing from one conveyor to another.
“There is a lot of development taking place regarding transfer chute technology especially as mines look at optimising existing plants to increase output. Bottlenecks occur at these transfer points because current technology is unable to handle the increased capacity of rock or coal being carried. We are looking at improving and developing this technology,” Henk explains.
Through computer software, Henk is able to simulate particle flow on a conveyor belt following a carefully-selected calibration process. “When looking at either coal or platinum ore you test the material, add the relevant frictional values to your properties in these models and then simulate the actual flow of material through the transfer chute.
“Though you are only looking at a model representing 15 to 20 seconds of real interface, we are nonetheless able to determine the velocity of the respective ore being transferred in the chute and predict the wear rate of the chute liner material and the receiving conveyor belt. We can ascertain the relevant impact pressure and material velocities which then gives us an indication of where we can expect blockages.”
The impact of transfer chute blockages should not be underestimated. Henk cites some of Eskom’s past power shortages as a case in point which were attributed to wet coal. Wet coal blocked the transfer chutes on the conveyor belts and in the storage bunkers and silos. “It might seem like an insignificant occurrence, but it did result in major power supply issues in the country,” he warns. Though similar incidents occur in other industries, Henk says they are not as newsworthy as the Eskom story.
He has been in the materials handling industry for 25 years, specialising in conveyor designs and transfer chutes. “Through combining the expertise I picked up over the years working on various coal and ash plants, along with the latest technology, I am able to develop computer generated models and solutions,” he enthuses.
He elaborates on how, by entering the correct values, you are able to determine how coal will behave on a conveyor belt. “From here you can then tell the project engineer what the conveyor and transfer chutes should look like and how the system should operate.”
Over the border
One of the projects completed in 2016 was for a pot ash plant in Canada. “For us this is a move in the right direction and we have also been approved on the company’s vendor list.” It was through his work with Sandvik SA that the opportunity came about to work for Sandvik Canada.
“We have the knowledge, so there’s no reason why we cannot provide our type of services to overseas companies,” he states.
“I recently did a Discrete Element Modelling (DEM) exercise for Sandvik SA’s new stacker reclaimers at Richard Bay coal terminal. These 11 000 ton-an-hour machines are used to load coal onto ships. To do the modelling at this scale puts you right up there with I believe the best in the world. With the experience South Africans have in the mining sector, I believe we can compete on even keel internationally.”
When starting the company three years ago, Henk knew that in order to be successful, he had to operate in other African countries. He focused his attention on Namibia, Botswana, Zimbabwe, Zambia and the DRC and is confident about the diversification of the company into these countries. “Though it is promising in these countries, the operating conditions are sometimes difficult. There are many pitfalls. We did go through a learning curve, but it has definitely been worth it,” he states.
Transfer chute technology
“Conveyor belts are expensive so companies are looking at ways of prolonging the lifespan of the conveyor belt. It is all about improving efficiencies especially on the hard rock applications,” he elaborates.
It is important to design the chute so it has the least amount of material degeneration as possible. Dust emissions have to be taken into consideration and have to be limited. “In order to minimise both potential implosions and explosions of dust, you need to build the model volumetrically so you can do simulations with the discrete models to show what the air flow looks like inside the chute,” he explains.
“These chutes are big and expensive. In the old days they were created by simply joining a few metal plates together. Now we use technology but it is an art to create the most efficient chute that complies with the relevant mining safety act. Given cost and environmental issues, you have to also ensure that spillage at a transfer chute is kept to a minimum. This is where the designer plays such an important role.
“Though we live in difficult times I am extremely positive about South Africa. I also believe this country is the gateway into Africa. As we are able to provide the expertise needed within the African mining industry, I intend on continuing to grow within the continent,” Henk concludes.