الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
ric acid is produced from phosphate rock by two
; viz. the Furnace (or Thermal) process and the
- c cess. The furnace process produces highly pure a=:--’ by reducing the ore to elemental phosphorus. The met—process produces phosphoric acid through acidulation =! ”i`e phosphate rock with sulfuric acid.
wet-process acid contains a number of impurities unich affect its properties and limit its uses. Among these impurities, iron, aluminium, and magnesium are the most objectionable. The presence of these ions causes sludge formation and increases the density and viscosity of the acid.
Several methods based on solvent extraction are used industrially to purify wet-process phosphoric acid. These
’methods depend on the extraction of most of the acid in an inert organic phase, leaving behind most of the impurities in the aqueous phase.
Only one industrial process is employed to purify the wet-process acid by using water immiscible acidic¬extractants. Such extractants can remove some metal ions from the acid by an ion exchange process.