Adsorbent material from stainless steel slag for eliminating pollutants

CSIC teams have developed a methodology to revalorise stainless steel slag from steel mills and transform it into an adsorbent material, which can be used for the treatment of effluents and industrial wastewater or for the purification of air pollutants.

There is a strong demand to find new uses for the high amount of waste slag produced in the steel industry. Pictured, a steel mill (Freepik)

Due to the environmental problem and the management of waste in landfills, there is a strong demand to find new uses for the high amount of waste slag produced in the steel industry.

CSIC teams have developed a methodology to revalorise stainless steel slag from steel mills and convert it into adsorbent material for the treatment of effluents and industrial wastewater or air purification.

It consists of a two-stage dissolution-coprecipitation process with a first phase with hydrochloric acid and a second phase in which sodium hydroxide is added. The result is a porous silicate matrix that has a surface area of approximately 150-250 m2/g, which is 67 times larger than unmodified slag. It has a higher surface area and pore diameter, comparable to reported values of commercial adsorbents.

The resulting material has a high surface area, and an adsorption capacity comparable to that of an activated carbon.

This high pollutant adsorption capacity would allow its use for the control and disinfection of polluted industrial wastewater, as well as for the adsorption of different pollutant or greenhouse gases. In particular, they could be used for the removal of ammonium, metals and for the adsorption of anions and organic compounds.

The adsorbent and the liquid can be easily separated by sedimentation, which allows them to be reused at low cost. Another advantage is that the process for obtaining the adsorbent material only requires components of low complexity and low cost, which would facilitate their mass production.

Contact:

Marisa Carrascoso Arranz
Deputy Vice-Presidency for
Knowledge Transfer -
CSIC
Tel.: 34+915681533
E-mail:
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