Following the completion of what has been the largest and one of the most technologically complex environmental projects in Latvia to date, the disposal of acid tar was finalised at the end of last year at the SIA Schwenk Latvija plant in Brocēni, according to Aija Jalinska, Head of Public Relations at the State Environmental Service (VVD).

In the cement production process, a total of approximately 49,000 tonnes of fuel derived from hazardous tar waste was incinerated. Remediation and recultivation works at the historically polluted site in Inčukalns parish were concluded by the VVD in May 2021.

When combined with auxiliary materials, the tar forms a secondary fuel; its incineration creates a cement production intermediate – clinker. In organising the cleanup of the historically polluted area, the VVD has introduced innovative solutions and promoted the efficient use of resources, thereby implementing the principles of the circular economy.

For example, the acid tar was processed into fuel and incinerated. The incineration of the tar and the resulting secondary fuel was carried out using a kiln that ensures a completely closed combustion process at an extremely high temperature (1500 °C), meaning that no new waste or wastewater was generated, the VVD explains.

The disposal of the pollution began in June 2018, when, as a result of collaboration between SIA Schwenk Latvija and the remediation contractor partnership Inčukalns Eko, an appropriate formula for processing the tar into fuel was developed. The tar was neutralised, with bypass dust (lime) identified as the optimal neutralising agent, mixed with bulking agents – wood shavings, dry sawdust, wood dust, and finely crushed wood chips – to improve the consistency of the tar, thus preparing the secondary fuel.