Due to the high demand for zinc alloys, Nyrstar was looking for an automatic and accurate dosing system for its Balen plant to flexibly compose alloys. Lybover BULK acted as main contractor keeping a tight rein on the reins. This was the only way to ensure timely delivery.

The project in a nutshell

The challenge

Nyrstar was looking for a turnkey dosing system for zinc alloy production in Balen, including necessary control and automation. Nickel, tin and bismuth, high-density substances, needed to be able to be accurately weighed and operators had to be able to flexibly select the quantities to be dosed. In addition, the new dosing installation had to be seamlessly integrated within the existing environment. Not an easy task with a multi-level installation and the tilting platform of the melting vessel. And finally, the entire dosing and transport operation had to take no more than 3 minutes. So there was no shortage of challenges.

The plan

For a suitable dosing system for each material, Lybover could turn to its own German partner EMDE Automation. To properly map the existing environment, a 3D scan was carried out at the start of the project. During the design phase, the engineers were able to accurately plan each component into the existing space based on that scan.

The implementation

Lybover BULK coordinated the project as main contractor. Lybover INSTALLATION took care of the installation of the dosing units and the extension of the existing support structures. Thanks to the thorough project approach and constructive cooperation between the various departments of Lybover, other contractors and the customer, the installation was delivered on time.

The Lybover way

Precise dosing of zinc alloy additives

Nyrstar is an originally Dutch company operating worldwide in metallurgy. Due to increasing demand for zinc alloys, it decided to recommission a stationary smelting plant at its Balen plant. Moreover, Nyrstar wanted to respond quickly and flexibly to the demand for various alloys. It therefore sought an automatic dosing system to add the metals nickel, bismuth and tin – each in different proportions.

Ticking clock? No problem!

Lybover BULK acted as main contractor and central point of contact in this project. John Morel, Head of Projects, at Lybover BULK: “There were already buyers for the new zinc alloys, so there was time pressure. The engineering, the purchase of the various components from the suppliers and the actual works on site had to proceed according to strict timing. It was up to us to oversee this as the main contractor. This is where we made the difference because we have in-house expertise in various disciplines. The dosing and conveying systems were a job for Lybover BULK. INSTALLATION colleagues looked after the assembly and extension of the existing support structures.”

“We make a difference because we have expertise across disciplines.”
– John Morel, Head of Projects, Lybover BULK

3 dosing units, 1 partner

The design and on-site installation were to be challenging. The dosing systems had to be placed on two levels in the existing building. Moreover, the components were not allowed to interfere with the tilting platform containing the melting vessel. Thanks to a 3D scan of the space, Lybover was able to work extremely precisely for the engineering of the dosing plant and supporting structures.

Lybover BULK presented three different dosing systems from partner EMDE Automation. “It is an added value that we could turn to our partner for all systems, both for the customer and for us. In terms of maintenance, for example, it ensures efficiency gains,” says Michaël De Baets, Business Development & Agency Manager at Lybover.

For the tin, there is a bag dump with weighing system into which operators pour the material. The bismuth is in bigbags that are emptied in a bigbag unloading station on weighing cells. The nickel is delivered in steel drums of 250 to 500 kg capacity. These are emptied into a storage hopper using a drum tipper. From there, a screw transfers the nickel to a smaller dosing hopper on weighing cells. Each dosing system was equipped with a customised dedusting unit, as dust control was also part of the project.          

“Several kilos of metal have to be weighed each time, but accurate to a few hundred grams. Together with partner EMDE Automation, we managed to realise a suitable solution for each additive.”
– Michaël De Baets, Business Development & Agency Manager

Lybover BULK chose those solutions to dose as accurately as possible. “Since the materials have a high density, only a small volume always needs to be measured out. The exact doses and proportions depend on the specific alloy. Batch sizes of 5 to 15 kilograms are involved, but the customer wants weighing to be accurate down to a few hundred grams,” Michaël De Baets clarifies.

A feat of ingenious craftsmanship

Once weighed, the materials enter vibrating pipes that lead them to the melting vessel. There, the zinc and additives are mixed. Once that process is complete, the entire platform tilts with the vessel to pour out the metal. So the dosing system and the vibrating chutes could not be in the way. “That is why we designed the vibrating chutes so that they can slide to the side. It took some thinking by experienced engineers to realise this solution,” says Michaël De Baets.

Constructive cooperation

After engineering and completion of the implementation plans, it was time to effectively build the plant – in just a few weeks. In that time frame, the control and automation of the dosing system also had to be implemented, as did the link with Nyrstar’s existing systems. The control system allows operators to choose the desired amount of additives or select a pre-programmed recipe. Result of all that work? Weighing out all the metals and transporting them to the melting vessel takes barely 3 minutes

“Thanks to our coordination work and constructive cooperation with the client, we managed to deliver this project on time.”
– John Morel, Head of Projects, Lybover BULK

“The tight timing was challenging. But thanks to our coordination work as main contractor and constructive cooperation with the client’s team, we managed to deliver this project on time,” concludes John Morel.