This manual has been developed to assist decision makers and others involved in the
planning and evaluation of systems for the chemical treatment of acid mine drainage
(AMD).

It addresses AMD chemical treatment at operating and decommissioned mine and
mineral processing sites in Canada. Currently used chemical treatment processes and
practices are summarized – including methods used to dispose of sludge.

In Canada, AMD chemical treatment is usually accomplished using proven and
effective lime neutralization/precipitation technology. As such, the manual addresses
concerns about the long term chemical stability of lime sludge. Alternate sludge
disposal strategies are presented.

The pro’s and con’s, net present values, sludge production volumes, etc. are presented
for three perpetual treatment strategies. The strategies range from the continued use
of conventional lime treatment systems to the use of an enhanced high density sludge
treatment system. Various sludge disposal options are also evaluated ranging from
deposition in a tailings basin to the smelting of sludge.

The chemical treatment and sludge disposal case studies may be used as a guide for
users in the planning or evaluations of AMD chemical treatment systems. Users are,
however, cautioned that AMD chemical treatment criteria are site-specific and that their
application will likely present special constraints and/or concerns.