Story: Superphosphate

Sulfuric acid coolers

Sulfuric acid coolers

A first stage in the manufacture of superphosphate is to produce sulfuric acid. Elemental sulfur, from Canada, is treated with acid. The reaction generates heat, and the resulting sulfuric acid must be cooled. Shown here are early cooling tanks. The acid is then mixed with rock phosphate to produce superphosphate and the hot, sticky product is then dried.

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Archives New Zealand - Te Rua Mahara o te Kāwanatanga
Reference: AANR 6329 26 DA 32786

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How to cite this page:

Arthur Duncan, 'Superphosphate - Making superphosphate', Te Ara - the Encyclopedia of New Zealand, (accessed 19 May 2022)

Story by Arthur Duncan, published 24 Nov 2008