Phosphates and Superphosphates

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Bulk shipping is the usual transport for these commodities. Single and triple superphosphate tend to be shipped in granular form. Are highly corrosive if packed too fresh or if humidity is encountered. Subject to loss in weight following seepage from containers.

Phosphate rock and/or fines A light brown to white rock which is sometimes crushed to make the phosphate fines. Varies in texture from a sandy powder to a lumpy material containing a large proportion of dust, and due to its free-flowing properties considerable loss may arise in course of handling. If the material is not perfectly free-flowing it cannot be used easily in the machinery set up for the manufacture of the acid phosphate and, although moisture contact does little of no damage, the commodity must be dried before it can be processed.

Superphosphate A rock phosphate treated with sulphuric acid: usually in granular form. A dry, free-running fertilizer, slightly acid in character. Moisture damage will render the commodity sticky and pasty and reduce both the fertilizer and material value. The commodity may be dried by hot air, but this may be an expensive matter.
Unduly high temperatures may cause the reversion of the soluble phosphate to the insoluble form, with consequent reduction in the value.
Generally superphosphates are liabelt to become wet in the vessel’s hold and if this occurs considerable difficulty may be experienced in discharge. On occasions the commodity may be hardened to such an extent that mechanical equipment is necessary to break it up before discharge takes place.

Superphosphate (Triple) Triple superphosphates (TSP) are made from phosphate rock treated with phosphoric acid and are not always three times more concentrated than single superphosphate (SSP).