In the ammonium phosphate–sulfuric acid–cement chain, phosphogypsum
and feed coal are delivered as raw materials for the
cement clinker production plant, where the sulfur follows three
pathways: some of the material is lost and emitted into the environment,
some becomes part of the cement clinker products, and
the rest becomes substances that are transformed into gases by the
cement kiln and supplied to the sulfuric acid plant. Furthermore,
the sulfuric acid plant divides its sulfur among four pathways: some
of the sulfur is lost to the environment, some is transformed into
liquid SO2 and delivered to the bromine plant as raw materials for
the production of bromine gas (Br2), and the rest is transformed into
sulfuric acid, which is delivered to the ammonium phosphate plant
or which itself becomes a final product. At the ammonium phosphate
plant, some of the sulfur is lost during production processes,
and some is incorporated into ammonium phosphorite products
and delivered to the cement clinker production plant. Finally, the
sulfur in the cement clinker production plant is included in products
that are delivered to the cement products production plant. In
this chain, feed coal that includes organic sulfur is an additional sulfur
source for the ammonia plant, and the sulfur will be transformed
into slag waste that is delivered to the cement clinker production
part for mixture with other materials.