Technological Challenges of Phosphorus Removal in High-Phosphorus Ores: Sustainability Implications and Possibilities for Greener Ore Processing

Abstract

With the present rates of iron ore consumption, currently unusable, high-phosphorus iron ore deposits are likely to be the iron ores of the future as higher-grade iron ore reserves are depleted. Consequently, the design and timely development of environmentally-benign processes for the simultaneous beneficiation of high-phosphorus iron ores and phosphorus recovery, currently a technological challenge, might soon become a sustainability challenge. To stimulate interest in this area, phosphorus adsorption and association in iron oxides/hydroxyoxides, and current efforts at its removal, have been reviewed. The important properties of the most relevant crystalline phosphate phases in iron ores are highlighted, and insights provided on plausible routes for the development of sustainable phosphorus recovery solutions from high-phosphorus iron ores. Leveraging literature information from geochemical investigations into phosphorus distribution, speciation, and mobility in various natural systems, key knowledge gaps that are vital for the development of sustainable phosphorus removal/recovery strategies and important factors (white spaces) not yet adequately taken into consideration in current phosphorus removal/recovery solutions are highlighted, and the need for their integration in the development of future phosphorus removal/recovery solutions, as well as their plausible impacts on phosphorus removal/recovery, are put into perspective.

Degradation‐triggered release from biodegradable metallic surfaces

“…The K sp of degradation products of c‐Fe samples ((Fe 3 O 4 , (K sp = 6.6 × 10 −109 ), FeO, (K sp = 3.5 × 10 −15 ), Fe 2 O 3 , (K sp = 1.1 × 10 −88 ), FeOOH (K sp = 1 × 10 −43 ) and ((Fe 3 (PO 4 ) 2 , K sp = 1.3 × 10 −30 )) 68‐71 had a relatively lower values than those of c‐Zn products ((ZnO, (K sp = 2.1 × 10 −17 ), (Zn(OH) 2 , K sp = 1.2 × 10 −17 ), (Zn 3 (PO 4 ) 2, K sp = 9.0 × 10 −33 )) 68,72,73 . The hardly dissolved Fe degradation products inclined to hinder O 2 diffusion onto Fe surface and thus limited the commencement of cathodic reaction and consequently resulting in a low degradation rate which will certainly affecting the curcumin release.…”

To spread or not to spread? Assessing the suitability of sewage sludge and other biogenic wastes for agriculture reuse

“…Phosphorus has raised at the attention in recent years due to the progressive depletion of mines and being included in the list of critical raw materials [ 5 ]. High-phosphorus iron ores could be depleted in 20–40 years according to Ofoegbu [ 6 ], even though more optimistic scenarios of up to almost 280 years have been also postulated [ 7 ]. The European Commission has estimated that, by recovering the sludge, about 20–30% of the need of P-fertilizers of the EU could be covered [ 8 ], thus making European farming much less dependent on imported mined and fossil raw materials, like phosphate rocks.…”

The crystal structure and chemistry of natural giniite and implications for Mars

“…In metal ore bodies the genetic history of giniite is less clear. Phosphorus is a common impurity in iron-bearing metal ore bodies (Cheng et al, 1999;Delvasto et al, 2008;Ofoegbu, 2019), and at the Silver Coin mine in Nevada, USA, phosphate minerals, including giniite, are products of acidic hydrothermal precipitation associated with the ore body (Adams et al, 2015).…”