There is growing consensus in the global phosphate industry that it is at
a turning point: it is not yet clear where it might best turn. Phosphogypsum
(PG) is pivotal to that decision, world-wide.
Phosphogypsum per se is not a new problem. For every ton of phosphoric acid
produced by the wet process method, some four to five tons of phosphogypsum
are also manufactured. The most obvious problem consists in what to do with
it. Currently, for a mixture of reasons that vary quite widely from country
to country manufacturing plant to manufacturing plant, and PG type to PG type,
a high proportion of the phosphogypsum is either dumped or stacked. The decision
to dump is partly affected by the relative leniency of environmental laws in
producing countries where PG is seen as essentially safe, but of no value;
the decision to stack is partly affected, notably in the United States, by
regulations which describe PG as radioactive and hence subject to use only
under permit. Stacks are a particular issue in Florida, which has some 20;
but there are many other stacks in the US, and many other countries, world-wide
which also have stacks. While the stacking regimen is held by many experts
to be unnecessary, and prohibitive of potentially beneficial uses, notably
in agriculture, it has the force of being the current norm. Both disposal methods
are increasingly seen as problems rather than solutions, since the one leaves
an unacceptable legacy on the land and immediate environs of the stack, the
other has unknown consequences for the wider ecosphere.
The visible impact of PG as a consequence of phosphoric acid production is
shadowed by an issue of increasing concern to commercial producers, that of
the risk of exposure to radiation whether to workers in the production process
itself, or to others in the product "value chain" as a consequence of the product's
use.
In both cases, the relative radiation risk to people or the environment from
the production of phosphoric acid or from the management of PG falls
below, mostly significantly below, the level of radiation to which we
are exposed through naturally occurring radioactive materials (NORM).
But when the precautionary principle is interpreted against a background
of absolute risk measurement, then even the most marginal increase in
risk may be held to be too much. This leads to the so-called "zero tolerance" approach,
one that was especially popular with policy makers in the 1990s. It may
be the case however, that, however well intentioned, the policy framework
that led to the promulgation of rules for creating PG stacks has now run its
course and that in the interests of a more adaptive, and ultimately environmentally
more sustainable management regime, that a fresh look needs to be taken
to the problem as a whole, and also from a global perspective.
The point of departure for the project outlined in this document is that
a beneficial, commercially appropriate, use for PG, based on objective data,
sensitivity to stakeholder requirements and best available practices, must
surely be a more appropriate outcome than dumping into water courses or the
oceans, or perpetual storage in "stacks". The project goal is to provide specific
guidance as to what beneficial uses of PG may be contemplated going forward,
and under what conditions, especially with regard to human and environmental
health, but also with regard to commercial viability and the requirements of
lifelong product stewardship. Given that the availability of phosphate fertilizers
significantly determines the world's food production capacity, if this issue
is not tackled successfully the penalty to be paid will levied well beyond
the industry itself.