Phosphoric acid manufacture

Chemistry ndProperties. The chemistry of phosphoric acid manufacture and purification is highly complex, largely because of the presence of impurities in the rock. The main chemical reaction in the acidulation of phosphate rock using sulfuric acid to produce phosphoric acid is... 

While only a few applications have been tested, there is no fundamental reason to suggest there may not be several others. The separation of HF from process air in phosphoric acid manufacture and HC1 from incineration flue gas are but two of these. Although the method will never be as broadly applied as say, distillation or absorption, its simplicity, selectivity and attractive economics make it likely to be employed in several specific situations. 

Donau Chemie A process for making saleable gypsum as a byproduct of phosphoric acid manufacture. The product is used to make partition panels for buildings. 

National Emission Standards for Hazardous Air Pollutant Emissions Group I Polymers and Resins National Emission Standards for Hazardous Air Pollutants for Epoxy Resins Production and Non-Nylon Polyamides Production National Emission Standards for Hazardous Air Pollutants From Secondary Lead Smelting National Emission Standards for Marine Tank Vessel Tank Loading Operations National Emission Standards for Hazardous Air Pollutants From Phosphoric Acid Manufacturing... 

Fig. 1.5-1. Flow Sheet for Phosphoric Acid Manufacture using the Dihydrate Process.

Two-stage phosphoric acid manufacturing processes producing phosphogypsum with lower impurity levels ... 

The impurity content can be affected by the way in which the phosphoric acid manufacturing process is carried out single stage processes, or newer processes, which lead to the hemihydrate, have a higher impurity level, so that further purification steps are necessary. Two step processes, which either lead via the dihydrate to the hemihydrate (Central-Prayon process) or via the memihydrate to the dihydrate (Nissan process), provide products, which can be utilized without further purification steps. Should further purification of the phosphogypsum be necessary, two types of process are possible ... 

Pollutants From Phosphoric Acid Manufacturing Plants... 

Use Source of phosphorus and phosphoric acid, manufacture of fertilizers, laser crystals. 

SulGdes- Sulfides can release H2S, which is a toxic gas, during acidulation. Sulfides produce reducing conditions, increase corrosion rates in phosphoric acid manufacture, and give NO release in nitrophosphate manufacture. 

Phosphoric Acid Manufacture-Updating Process Technology. 1986. Phosphorus and Potassium, 143 25-33. 

There are two other aspects that should be mentioned here that may directly affect the choice of the milling process. First, the uranium ore often contains other metals that have commercial value, like vanadium or niobium, for example, and their recovery may influence the process selected for uranium recuperation. Second, uranium itself may be a by-product of other processes like gold extraction, niobium, and tantalum production or phosphoric acid manufacture. Thus, recovery of low levels of uranium from phosphates, columbite, or gold-bearing minerals may not be economical in itself, but extracting uranium as a by-product from the waste streams of these operations could be commercially sensible. 

Applications include pipe and tubing in phosphoric acid manufacture, sulfuric acid manufacture, and fertilizer and pesticide manufacture. The alloy is also used in the evaporators of commercial wet process phosphoric manufacturing systems. This process contains complex mixtures of phosphoric, sulfuric, and hydrofluoric acids and various oxides. Under these conditions, the corrosion rate for alloy G-30 was 6 mpy as compared to 16 mpy for alloy G-3 and alloy 625. 

Phosphoric acid Manufacturing fertilizers, detergents, food additive, clean solvent... 

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