Burnt shale

Value-added revenue streams

Enefit increases the efficiency of energy production and guarantees extra revenue streams by utilizing by-products, such as burnt shale and limestone. Enefit helps to create additional value from oil shale utilization and boost new business opportunities in road and port construction, agriculture and new energy projects.

Burnt shale

The oil shale ash, recognised as burnt shale in the world nomenclature produced as a by-product during oil and electricity production is an environmentally safe and valuable commodity. In Estonia, the burnt shale is a standardized and registered material, sold at the market for use in different fields.

Where the burnt shale is used?


The burnt shale has been used for soil treatment as a liming agent for the decades in Estonia and its neighboring countries. Burnt shale contains elements that neutralize acidic environment in the soils and increase the soils' fertility. It is effective in enrichments of fields, growing tree cuttings and stimulating forests' growth.

Burnt shale has been successfully used for a couple of decades as an important and unique additive in production of oil and gas wells cements.

Burnt shale has recommended itself as an unique additive in well casing cements that has been used widely in wells that are situated in worlds most complex geological conditions at Siberian petroleum basin. Using burnt shale as an additive in well casing cement allows later in oil or gas production ensure the well resistance to geological impacts, corrosion and acidic environment, which has a crucial importance in ensuring production process sustainability and safety.

Burnt shale use possesses high stabilisation properties with no negative impact on the environment. Enefit participates in the projects involving road construction projects in Estonia and major ports of the Baltic Sea. The burnt shale is considered as a substitutor of cement in stabilisation of soft soils (clays, peat, sea sediments etc.), including stabilisation of environmentally hazardous elements containing the soils.

Burnt shale is used as a main component in cement, concrete, aerated concrete blocks and dry construction mixtures. Each recycled ton of ash offsets nearly one ton of CO2 emissions that would otherwise be released in the cement production process. Cement containing burnt shale has been used in the construction of the Tallinn TV Tower.

Oil shale ash plateau has been used successfully as a foundation for renewable energy production units, such as wind parks.

Burnt shale may be used in the plastics industry as a filler material instead of chalk or talk. Several studies are under way in Estonia.

Burnt shale potential and perspective fields of use

Backfilling underground mines.

Concrete made from burnt oil shale can be used for backfilling mines, which allows the extraction of all oil shale deposits. No oil shale deposits are left underground in the form of support pillars.

Enefix and Enefix+

The environment-friendly burnt shale based Enefix and Enefix + soil treatment improves the site conditions for plants, helping the soil to absorb nutrients, and reducing the risk of plant diseases- also suppresses moss growth in lawns.

Enefix and Enefix + offers flexible approach in liming and soil improving works to large and middle size farms, also for home gardening.

Enefix and Enefix+


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