There is currently only one pulp mill Horizon Pulp & Paper Ltd operating in the Baltic States – in Kehra, Estonia, that manufactures a wide range of paper products for the packaging industry. This is now also the only source of lignin in the Baltic States. Nevertheless, up to now, the lignin present in black liquor from the Kehra Pulp & Paper mill had not been investigated. The aim of our research was to extract sulfate lignin from Kehra industrial black liquid, characterize its chemical composition and evaluate the characteristics of surface tension. Based on the results obtained in the research, it has been concluded that the derived sulfate lignin, in terms of its parameters, does not differ substantially from other industrial or commercial sulfate lignins. It has been established that, with an increase in the concentration and a decrease in the pH of the sulfate lignin solution, its surface activity at the solution-air interface and in the oil-to-water emulsions increase. If the concentration is high, the emulsion stability is better in acidic environment, if low – in alkaline environment due to different emulsion stabilization mechanisms. It has been found that the presence of 0.1 M NaCl in the sulfate lignin solutions positively influences on its surface activity of, which is connected with the increase of the hydrophobicity of sulfate lignin molecules as a result of the increase of ionic strength.