Compost refining techniques include adaptations
of the separation and size reduction techniques already described in the Critical
Review Sections: Pre-Processing Methods - Separation Technologies and
Pre-Processing Methods - Size Reduction. In addition, operations may
include the production of fine pellets (around 5 mm diameter) from composts,
and/or bagging of the compost (Newport 1990). A number of developmental techniques
have also been evaluated, for example the use of electric fields or chelating
agents for the removal of trace elements from composts.
For the most part the “product” is the organic
rich fraction. However, dense fractions with low organic content (for example
rich in glass and ceramics) may be of use in landfill as daily cover or in
drainage layers.
