WESTKALK

WESTKALK Vereinigte Warsteiner Kalksteinindustrie GmbH & Co. KG, Warstein/Germany, is currently investing 3 M € in state-of-the-art electrical engineering at its Warstein site (Figure 1). Transformers, switchgear, switch cabinets, relays and power supplies have been gradually replaced since spring 2025. The project is scheduled for completion at the end of 2026. The work is being carried out by the specialist company Decker from Brilon/Germany.

The reason for this is the ageing switchgear technology from the 1980s. Switches and relays are worn out and cable contacts are brittle. It is becoming increasingly difficult to procure spare parts. The procurement of transformers in particular is taking time: Electrical components are needed everywhere to shape the energy transition, which is reflected in long delivery times. WESTKALK has ordered five new transformers.

WESTKALK’s electricity requirements are considerable. The primary crusher alone requires 400 KW (approximately 600 hp) of power. Added to this are the dust extraction systems and conveyor belts: Everything at WESTKALK is powered by electricity. This requires a voltage of 400 V three-phase current. However, 10,000 V (known as medium voltage) is supplied, which is then stepped down. The company needs its own transformers for this. Suitable housings for this will be delivered shortly, weighing up to 60 t and, due to their extra width of approximately 3 m, can only be transported at night by low-loader.

State-of-the-art technology is being installed. The switches and relays, e. g., are encapsulated with a special protective gas to minimise the arc effect during switching. Sulphur hexafluoride (SF6) is no longer used for this purpose. Instead, Siemens’ particularly environmentally friendly Clean Air process is employed. This insulating medium consists exclusively of natural components of the ambient air, such as nitrogen or oxygen.

In future, WESTKALK intends to become self-sufficient in terms of its power supply. Approximately 1.5 MW is required on a regular basis. An appropriately sized, environmentally friendly photovoltaic system is in the planning stage. (WESTKALK/Si.)

This year’s winter repairs in the WESTKALK Vereinigte Warsteiner Kalksteinindustrie GmbH & Co. KG in Warstein and Kallenhardt, both Germany, were concluded with the replacement of a more than 820 m long rubber conveyor belt in the Kallenhardt works (Figure 1). The replacement had become necessary after seven years because the belt hat worn severely over the years. During this time, the belt had also been mended at several points already. The repair project cost over 70,000 €. WESTKALK regularly uses the winter time for maintenance and repair work because the plants in the processing industry, such as cement works, are also regularly serviced during this time and many construction sites come to a standstill because of the weather.

It took experts from a specialist company two days to mount the 1,000 mm wide conveyor belt from a total of four rolls onto the conveyor system. Each of the three 250 m rolls weighed about 7 t. Even the smaller roll weighed over 3.5 t. Particular care needed to be taken in joining the sections, which was done by hot vulcanisation with a vulcanising press. This works in a similar way to patching a bicycle inner tube, but at temperatures of approximately 150 °C. The extremely tear-resistant, robust belt has a fabric lining made of polyamide and polyester. Around it there are cover plates, which are 8 mm thick on the material carrying side. The underside is coated with 3 mm of rubber. The employees were specially trained for the installation work using the wheel loader.

Conveyor belts are the main means of transport in the processing plants of the stone industry. At the Kallenhardt and Warstein works of WESTKALK there is a large number of rubber conveyor belts of varying lengths and widths; some only 1 m long, others 20 m or more. By far the longest conveyor section is found in the plant at Kallenhardt. It is a double-level belt system that spans the section between the primary crusher and the storage silo, or the pile of material to be washed, with two conveyor belts arranged one above the other. The top conveyor belt is enclosed in order to ensure that the crushed limestone reaches the silo dry and without dust being blown around. There is a particular risk of wear on the conveyor systems if large, sharp-edged stones or metal parts slit open the belt lengthwise.

Incidentally, the old belt parts are not waste; they are reused. Old conveyor belts, e. g., are very popular with farmers and are used for a variety of purposes. (WESTKALK/Si.)

Just a stone’s throw from the limestone quarry in Kallenhardt, there is now a new geocaching location. The search leads to a lookout point with a stunning panoramic view. At an existing information board, the “cachers” – and, of course, also walkers who are not hunting for the cache – can learn about the nature in front of them.

The quarry operator, Warstein-based family company WESTKALK, was informed about the new geocache in advance and welcomed the idea. Geocaching is all about discovering landscapes or finding out more about important cultural assets, something that WESTKALK authorised representative Marius Risse knows a bit about (Figure 1): “We have both of those things here. The view across the landscape is not only hugely impressive, it also demonstrates the harmony between raw material extraction and nature. It’s hard to believe, but a quarry is actually the perfect habitat for lots of animal and plant species. There is a lot to discover in and around the Kallenhardt quarry.”

Geocaching involves searching for hidden containers, called “caches”, using GPS data. This data is collated in online databases, where users can also document their finds. As well as the quarry, many other caches in Kallenhardt, Warstein, Rüthen and across Germany can be found at www.geocaching.com. (WESTKALK/Si.)

The biodiversity in a quarry is often much higher after the end of excavation work than prior to starting. This is reflected by the decades of experience and the previous data of the biodiversity database of the Baden-Württemberg Industry Association of Stone and Earth (ISTE). The Baden-Württemberg database project will also be available soon throughout Germany. Then the data from the Warstein-based family-run company Vereinigte Warsteiner Kalksteinindustrie GmbH & Co. KG (WESTKALK) can also be updated there.

Up to now mappings and values from studies of excavation works in south-west Germany can be found in the database. For the promotion of biological diversity the association is working closely with the Nature and Biodiversity Conservation Union (NABU). Data from before, during and after completion of the excavation should be recorded in the nationwide database. Data sources are regularly the reports and assessments which an excavation company requires in order to obtain a permit for the company.

Manuel Sedlak has been a keynote speaker on environmental law and nature conservation for twelve years at the ISTE. He explains: “During the mining work new animal species migrate to the mining sites, e. g., yellow-bellied toads, green toads, little ringed plovers, and also plant species. They are species which take over the mining sites as so-called pioneer habitats and then also remain there.” For nature conservationists abandoned quarries are a paradise (Figure 1).

WESTKALK can confirm the database values from their own experience. “Of course we’re familiar with the eagle owl, who needs the jagged rock faces in our operation for nesting. We can account for rare orchid specifies and Roberts quarry is really a model habitat with its goats and the plant species growing there”, says Marius Risse, authorised representative at WESTKALK.

The database information is not an end in itself, but helps to prove that the excavation companies are operating effectively. For the application for approval an excavation company must ensure that after the end of the work at least the previous biodiversity level is restored. Otherwise, they do not obtain approval. Sedlak: “This is EU law and therefore applies equally throughout the EU. However, you can clearly see that Germany observes the enforcement of the standards.”

(WESTKALK/Si.)

With regards to work safety, health- and environmental protection the enterprise WESTKALK Vereinigte Warsteiner Kalksteinindustrie GmbH & Co. KG, Warstein/Germany, is planning to install an own extraction system for limestone spillage in their jet mill at the factory in Kallenhardt (Figure 1). This is supposed to improve the plant’s cleanliness and reduce dust exposure for staff members and surroundings long-term. WESTKALK budgets a five-digit number sum total in this year’s investment program.

The development of dust and spillage is oftentimes not preventable when it comes to mining, fracturing, and screening of limestone. Especially the transport of limestone on conveyor belts causes spillage to accumulate on floors, paths and corners or recesses. Like that, material is formed on the whole premise. Due to this, several tons of valuable resources get lost within each year. In order to curb this, changes in the jet mill are to be performed this year. At present WESTKALK conducts root cause analyses to determine the amount of spaces the dust accumulates in. A high-performance industrial vacuum cleaner is supposed to help with this at the factory in Kallen-hardt to prevent the dust depositing as far as possible.

Currently a suction vehicle, which is rented by WESTKALK externally, takes care of the dust – not without disadvantages for the entire neighborhood. “That’s why we want to start to get rid of the cause. Not just the result”, says Guido Mausbach, the company’s technical manager. With more than 1,500 € rental fee per vacuum truck it is not just expensive to hire the services but „extremely loud as well“, Mausbach says and refers to neighborhood complaints: “Unfortunately there’s only one possible location for the vacuum truck and if the wind happens to blow from an unfavorable direction, our neighbors can hear the truck very distinctly.”

So far, the vacuum trucks have been deployed twice a year at the plant. “That’s the only way to thoroughly clean the plant.” With their investment decision WESTKALK also bears in mind their surroundings. With a regular cleaning of the premises, there’s supposed to be significantly less pollution and strain for environment and residents. (WESTKALK/Si.)

Fourteen budding engineers for raw material extraction from the TH Georg Agricola University in Bochum/Germany visited WESTKALK’s Kallenhardt plant on a study trip (Figure 1). They were accompanied on their excursion by a drone, which documented the university group’s activities with a photo flight.

Nowadays, drones are used for surveying, which is required in quarries for their annual mass calculation, to enable precise calculation of the fractional interest rate for the lessors and the product stock for inventory purposes. WESTKALK does not currently use drone surveys. The THGA university groups’ excursions now regularly involve drone flight documentation, says excursion leader Prof. Albert Daniels.

As part of their quarry visit, the stu-dents learnt about the geology of the compacted Devonian lime and the large-scale technology used at the Kallenhardt plant. Even three years after commissioning, the crushing plant, with its combination of drum screening and impact mill, is unique in Germany. The project was funded by the Federal Environment Ministry.

The WESTKALK pilot project contributes to an improved use of deposits and therefore to a significantly reduced land use – as the Federal Environment Ministry stated in a press release at the time. The argillaceous substances are first crushed in a drum screen and then filtered out. The pre-screening material produced is cleaned in the stone washing plant to process the limestone it contains into marketable products. Owing to the improved separation of valuable rock and waste material, blasted raw material heavily mixed with clay can be transported to the crushing plant. That reduces the proportion of unused valuable rock on the spoil tip from around 30 to less than 5 %. The resulting increase in the usage rate of the deposit leads to an almost optimal raw materials efficiency. (WESTKALK/Si.)