Using the ash

Corporate purpose


Impacted SDG

During 2018, CMPC focused on the design of a Zero Waste Plan to reduce the quantity of waste and attain waste management independence. In order to achieve this goal, projects have been designed that reduce the generation of environmental debt and seek alternative uses and/or reprocessing, aiming always at a Circular Economy Strategy.

Therefore, CMPC has been carrying out joint studies with the University of Concepcion in Chile since 2010 to use slaked lime sludge and effluents, dregs and grits and biomass ash. All are solid waste from the pulp manufacturing process that until now has had no productive use.

In 2013, most of the solid waste from the pulp manufacturing process was classified as sub-products that presently possess the necessary environmental permits for other uses: e.g. in forest plantations, sales to third parties, incineration in biomass boilers, and internal disposal.

Therefore, the studies that began in 2010 were transformed into innovative projects for the use of solid waste to improve soil quality on forest plantations and agricultural land.

In 2018 the following goals were achieved:

  • Incineration of 100% of the effluent sludge from the biomass boilers.
  • Sale of lime sub-products (lime sludge and lime kiln dust).
  • Transfer and application of ash to forest plantations.
  • Collection of 12,236 metric tons of ash from the Pacifico and Santa Fe mills.
  • Disposal of almost 200 metric tons of ash; and in 2019, expected disposal of 1,865 metric tons of ash .


Ash collection August-December 2018 (metric tons)
Santa Fe Mill Pacífico Mill Total
9.019 3.217 12.236


Ash collection January – February 2019 (metric tons)
Santa Fe Mill Pacífico Mill Total
1.449 706 2.155