Hydrometal from Engis in Belgium processes non-ferrous metal residues by hydrometallurgical technologies into valuable products, including zinc oxide, for more than fifty years. In doing so, they offer an alternative to dumping waste and contribute to the development of sustainable solutions.

Limburg Filter has been asked to support Hydrometal to get a better performance of their filter presses. We have a lot of knowledge and experience and can advise Hydrometal on the optimization of processes. We also supply various materials for the filter presses, such as Leaktite® filter plates and filter cloths.

The Coat Factory

The Coat Factory b.v. from Heesbeen gives color and protection to many types of steel and non-ferrous materials. This process creates waste water and sludge. For years, Limburg Filter has supplied the filter cloths for the filter press for sludge dewatering. At a certain point, our customer notices that the sludge processing takes longer and longer. The filter cakes also appear to be much less dry than in the past.

The customer wonders whether there is something wrong with the quality of the last delivered filter cloths. During an inspection of the wastewater treatment plant, we find that the purified water in the sludge settling tank is not clear. It subsequently appears that the lime milk dosage does not work properly. A shortage of lime milk leads to cloudy water. The particles that make the water cloudy clog the filter cloths during sludge dewatering.

The lime dosage has now been adjusted and the purified water is clear again. The filter cloths have also been cleaned in acid to dissolve the blockage. The filter cloths now dewater as good as before.

‘We have peace of mind again with regard to water purification!’ – The Coat Factory

Gulpener Bierbrouwerij

Our customer Gulpener Brouwerij – to whom Limburg Filter has been supplying filter bags for making beer for years – opened a new brewhouse last year. The goal is to be able to brew all beers by 2030 without the use of fossil fuels through innovative brewing techniques and processing of local raw materials. The brewery is the winner of the Plaque for Sustainable Entrepreneurship, one of the King Willem I Awards. This prize was recently presented by Queen Máxima. The photo shows Máxima throwing hop bells she picked herself – packed in our filter bag – into the brew kettle.”

Photo: Marcel van Hoorn


Clients can contact Limburg Filter not only for the production and installation of filter presses, but also for help and advice. The Greek company PIRAIKI METALS, which processes zinc residues, had recently ordered filter presses of Chinese manufacture. However, due to the corona measures, the supplier was unable to provide on-site support with the start-up of the filter presses. Mr. Pascal Briol, managing director of PBSIM Engineering and advisor to PIRAIKI METALS for hydro-metallurgical processes, knew that Limburg Filter has a lot of experience with these filter presses and established the contact between them and us. Limburg Filter went to site in Greece and helped PIRAIKI METALS with the commissioning and start-up. The filter presses have now been successfully put into operation.

Industrial wastewater test research at Wupperman Staal

As an innovative developer and steel processor, Wupperman Staal Nederland, which will celebrate its 150th anniversary this year, works for the automotive industry. In the factory in Moerdijk, steel coils are galvanized in a continuous process. This process produces various types of waste water.

Together with Geonwater and Pentair, Limburg Water has carried out tests on the industrial waste water of Wuppermann with the aim of improving the process technology of the water treatment plant. Based on the test results, we have designed a full-scale installation based on innovative techniques and with more capacity than the current one. We are currently building a filter press for sludge dewatering. At the end of this year, the new water treatment system is planned to be operational.

Limburg Filter in action for rivers

Every year we donate part of our profit to charities. This year we opted for Maas Cleanup: a major cleaning campaign in and around the Maas. Because Mother Maas is close to our hearts, and because the pursuit of clean water is in our company’s DNA. On September 19, 2020, we rolled up our sleeves, together with employees and associates, in a mission to clean up the Pietersplas. A great initiative that stimulates awareness surrounding the litter problem. We collaborated with great pleasure and satisfaction.

Milestone for Attero Moerdijk

Attero waste-to-energy plant in Moerdijk has already processed 100,000 m3 of sludge with the new filter press by Limburg Filter. A milestone, because with the filter press the moisture content in the filter cake has been reduced to the desired level.

On the go for Rolls Royce

This brand reminds most people about luxury cars, but for us aircraft engines appear first. Via CTECH from England, our prime supplier for installations and chemicals to treat industrial waste water, ordered a fully automated filter press to be supplied to one of the aircraft engine factories of Rolls-Royce. A prestigious order which challenged ourselves on the application of knowledge and experience.

European grant for F-cubed

The European Commission has officially commissioned F-Cubed, a project for renewable energy sources based on biogenic residual material, such as orange peel and olive pulp. Limburg Filter is a partner in the project together with research institute TNO and other European companies and knowledge institutes.