- Waeltz Facility – Significance and Benefits
The “Waeltz Facility for Processing Zinc-Bearing Materials,” located in Kardzhali, is a plant designed for processing zinc-containing materials. It processes industrial waste accumulated over decades by the insolvent company “OCK” AD, thereby achieving a significant environmental benefit.
Bulgaria significantly lags behind in addressing the problem of developing and implementing an effective program for utilizing industrial waste.
The Waelz facility contributes to resource efficiency through the reuse and recycling of metal-containing waste via a pyrometallurgical process. This reduces landfilling and limits the harmful impact on the environment and human health. In this sense, the Waeltz installation fulfills one of the main goals of the circular economy – a production model that minimizes waste – and clearly serves as a benchmark for the effective implementation of the EU Circular Economy Action Plan, as well as the Strategy and Action Plan for the transition to a circular economy of the Republic of Bulgaria.
- Description of the Process, Raw Materials, and Final Product of the Waeltz Facility
2.1. Raw Materials Used in the Waeltz Facility
The raw material base for the Waetz facility consists of zinc-bearing materials, which are waste from the operations of the former “OCK” AD, generated after its privatization, and acquired by “Harmony 2012” EOOD. These include lead slag, ferrite zinc cake, and sludge from wastewater treatment plants. It is also planned to use dust from electric arc furnaces, which is not yet available on-site.
These raw materials are solid substances, do not contain volatile organic compounds, do not emit gases under normal atmospheric conditions, and therefore have no characteristic odor.
2.2. Waeltz Process
The Waeltz process is a pyrometallurgical enrichment process. The zinc-containing materials and auxiliary materials are fed into a slowly rotating, slightly inclined tubular furnace. By heating with natural gas to the required temperature, the zinc compounds are transformed into elemental zinc or zinc oxide, which then evaporates. The zinc vapor is subsequently oxidized to ZnO and carried with the furnace gases as so-called “veltz oxides”—a material with a high zinc content, which is the target product of the process.
The Waeltz facility is a closed system with precisely defined and approved stationary emission sources, which are subject to continuous monitoring. Air emissions are released in a controlled manner via chimney K1. Measurements conducted by the Regional Laboratory – Stara Zagora of the Executive Environment Agency confirmed that all emissions from K1 are within permissible norms.
2.3. Final Product and Main Waste from the Waeltz Facility
The main product of the Waeltz process is Waeltz oxide, CAS No 69012-63-1, EC No 273-760-6. Detailed information about its physical and chemical properties is available on the European Chemicals Agency (ECHA) website:
https://echa.europa.eu/bg/brief-profile/-/briefprofile/100.067.035.
According to this data, Waeltz oxide has no odor.
The production process also generates waste called clinker (waeltz clinker). Currently, the waeltz clinker is classified as non-hazardous waste. On 16.12.2024, a certificate of conformity of production control No. 1871 – CPR – 0410 was issued by the notified body “Center for Testing and European Certification,” certifying veltz clinker as a product under the name “artificial rock material.” Its registration as a product is pending at the Ministry of Environment and Water. It is planned to be used in earthworks during road construction and rehabilitation. With additional mechanical processing, waeltz clinker could find broader applications.
- Permits and Development Stage
3.1. Permits
The Waeltz facility was built in compliance with regulatory requirements and environmental procedures:
- Procedures under Chapter Six of the Environmental Protection Act (EPA) were properly conducted, and valid Environmental Impact Assessment (EIA) Decision No. ХА-2-4/2019 and Screening Decision No. ХА-51-ПР/2021 (effective as of 22.10.2021) are in place. These confirm the application of Best Available Techniques (BAT) under Article 99a of the EPA;
- The installation was constructed according to approved investment projects and a valid building permit No. 85 dated 26.06.2020, along with effective orders for changes during construction: Order No. 66/30.11.2020, Order No. 48/17.08.2021, and Order No. 72/29.11.2021;
- Completion of construction and readiness for commissioning is certified by Protocol Form 15 dated 14.02.2023, drawn up according to Regulation No. 3 of 31 July 2003 on drafting construction protocols;
- “Harmony 2012” Ltd. is the holder of Integrated Permit No. 123-Н-1/2023, updated with Decision No. 124-Н-1-И0-А1/2024 issued by the Executive Director of the Executive Environment Agency;
- “Harmony 2012” Ltd. is also the holder of a Safety Report and Internal Emergency Plan for the installation, approved by Decision No. 251-A0/2023 and updated by Decision No. 251-A1/2025 by the Executive Director of the Executive Environment Agency.
3.2. Development Stage
Currently, comprehensive testing is being carried out under the Spatial Development Act, pursuant to Art. 7, para. 3, item 17 of Regulation No. 3 of 31 July 2003 on drafting construction protocols. Upon successful completion of these tests, a 72-hour operational trial will be conducted under working conditions.