Sibelco Europe: more than just marl

Aluminum hydroxide, manganese dioxide, cristobalite, barite, calcium silicate, bentonite … all these exotic sounding minerals are processed – just like Limburg marl – from raw minerals to fine powders by Sibelco Europe in Maastricht. As an ingredient for a variety of industries, construction and even animal husbandry. Sibelco is a special, exciting client of Wivé Techniek. We spoke with Maintenance Manager Jos Wauben, an expert in both the processes and products of Sibelco.

“Our parent company does predominantly sand mining for glass production. Here in Maastricht, we work with many more different minerals. That makes us less cyclical. Moreover, we try to adapt to the market. For example, we switched to recycling waste from the glass fiber plant with one of our production lines. We grind it into powder, from which they can then make fiberglass again.

But our specialty is still producing minerals in powder form. We make fine powder from large chunks, where we can accurately meet the customer’s specification: average area per grain, particles per gram, grain size distribution and the fineness of the product. That’s what we do. To do this, we use a wide range of equipment, from ball mills the size of a large living room, capable of handling 50 tons of marl per hour, to small units with a capacity of 150 kilograms per hour.

The processes are always roughly similar. It starts with crushing, for example in a hammer mill, in which hammers rotate on a rotor and smash the pieces. We also have a mill with a rotor that picks up the pieces and hurls them against a steel wall. In addition, we can break chunks by crumbling them between two walls. Once the pieces are fine enough, they go by conveyor belt or tray elevator to the screening machine. Here we drop them against a strong hot air stream.

The lightest particles move with the air and can pass a fan. The heavier particles are thrown out of the airflow by this fan and fall back into a grinding machine. For example, a ball mill: a drum that lifts heavy steel balls and drops them back onto the mineral. Then everything goes back to the wind sieve, the larger pieces back to the mill and so on.

In our processes – crushing, grinding, transporting, drying and screening – wear is inevitable. It is the job of Maintenance to extend the service life of the installations with wear-reducing measures, including the use of wear-resistant materials. Wivé is a good partner in this, because they not only supply the materials, but also provide expert advice and, if necessary, even provide complete assembly. For example, we were planning to repair a worn pipe by applying a layer of wear-resistant concrete to the inside. After consulting with Wivé, we decided to replace the entire pipe, with Wivé taking care of the assembly from A to Z.

It involved a 130 cm wide pipe between a pre-separator and a filter unit. A stream of warm air containing fine dust is continuously blown through this. This continually sandblasts the pipe from the inside, as it were. The pipe dated from the construction of the ball mill in 1972 and there were no more drawings.

That made things more difficult for Wivé, because they had to measure everything for the construction of a new pipe made of steel with welded-on wear-resistant plates.

That has to be done right the first time, because you don’t just grind wear-resistant material to size afterwards.

To replace the pipe, we shut down the ball mill for one week. We could concentrate on all kinds of other jobs, because Wivé was responsible for the pipe. Turns out … their supplier made a mistake, so the new pipe didn’t fit.

That was a bit of a scare. At such a moment it becomes clear what you have in common. Wivé accepted the setback and took responsibility. With a lot of inventiveness, perseverance and hard work, the problem was solved. In time for the restart of the installation, exactly on schedule. Look, as a client you can’t complain then.