Advanced oxidation processes for wet-process phosphoric acid: Enhanced phosphorus recovery and removal of organic matters

Role of Additives: Modified Hemihydrate Phosphogypsum Morphology and Enhanced Filtration Performance of Wet-Process Phosphoric Acid

“…The EDS results of hemihydrate phosphogypsum obtained with and without PVA are listed in Figure 8. The content of carbon in phosphogypsum with the addition of PVA is more than twice as much as that of hemihydrate phosphogypsum without any additives and the carbon of phosphogypsum without any additives comes from the organic matter in phosphate ore, 37 which also indicates that PVA remains in phosphogypsum and may participate in the formation of a clusterlike morphology despite a very weak interaction with the crystal plane of CaSO 4 •0.5H 2 O (Table 2).…”

Leaching of phosphate ores with lower dissolution of metallic impurities: the dual role of sodium oleate

“…13 Despite this, the efficient utilization of medium and low grade PO is increasingly important. Different methods have been proposed for the efficient utilization of PO by reducing the loss of phosphorus content, such as advanced oxidation processes, 14 foam control, 8 and organic acid leaching. 15,16 Generally speaking, the leaching performance is efficiently improved by selecting appropriate agents or adopting intensication methods.…”

Removal of Organic Matter from Tunisian Industrial Phosphoric Acid by Adsorption onto Purified Natural Illite/Kaolinite Clay: Kinetics, Isothermal and Thermodynamic Studies

“…Among these, sulfuric acid is predominantly utilised due to its lower cost, simple operation, and ability to exploit lower-quality phosphate rocks [ 6 ]. Unfortunately, undesirable impurities from phosphate rock such as fluoride, heavy metals, and organic matter (OM) are inevitably leached out with the phosphorus [ 7 ]. Some of these elements affect the acid quality and limit its end use.…”

“…Organic matter includes humic substances, aromatic compounds, phthalates, and many other carboxylic acids [ 7 ]. Based on its geological source, the organic matter content in sedimentary phosphates rocks varies between 1% and 3.5% [ 9 ].…”

“…Therefore, it is crucial to decrease the concentration of the organic compounds in wet phosphoric acid to achieve the required acid quality for the production of environmentally friendly fertilisers, and various industrial and food-grade phosphate derivatives. Several techniques have been deployed to eliminate organic substances from wet phosphoric acid, such as chemical oxidation [ 7 ], ion exchange [ 15 ], solvent extraction [ 16 ], ionic flotation [ 17 ], membrane processes [ 18 ], extraction with impregnated resins [ 19 ], and crystallisation [ 20 ]. Nevertheless, the use of these techniques has been consistently limited because of their high energy requirements, significant costs linked to organic solvents, oxidants, and resins, as well as the inherent risk of secondary pollution [ 21 ].…”