mat

chemical (5)
Plastic and rubber (17)
Paper and paperboard (1)
Metal (3)
animal and vegetable organic (2)
wood and biomass (2)
inorganic and glass (2)
textiles and leather (3)
Others (3)

+



Paper mill sludge as a by-product

Stora Enso Barcelona SA is a company dedicated to the manufacture of cardboard for several applications in the packaging sector. During the process of manufacturing cardboard from recycling, significant quantities of wastewater with a high content of solids (sands, fibers, mineral charges) and organic material are generated. These waters are treated in a treatment plant that has a primary treatment (physicochemical) and a secondary treatment (2 biological reactors). From these treatments, purified water and sludge are generated (13,000 t/ year).

Thanks to the composition of the sludge, with large amounts of carbonates and kaolins, these can be managed as by-products in the Catalan regulatory framework by different industrial sectors, since they can substitute some of the raw materials used in other production processes. These by-products can be used in some of the manufacturing processes pointed below:

  • Manufacture of ceramic material for construction, as a substitute for a part of the clay.
  • Cement manufacturing, as a substitute for a part of natural calcareous stone.
  • Manufacture of cellulose, as a substitute for part of the virgin cellulose fiber.

This substitution represents a saving in the consumption of natural resources and a reduction in the disposal of waste in the landfill.