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StackFree.com
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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 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.
For further information please contact
Professor Julian Hilton
jhilton@aleffgroup.com
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