Khedr Houda A, Ebraheem Mohamed O, Zayed Ahmed M
Geology Department, Faculty of Science, New Valley University, New Valley, Egypt.
Applied Mineralogy and Water Research Lab (AMWRL), Geology Department, Faculty of Science, Beni-Suef University, Beni Suef, 62521, Egypt.
Sci Rep. 2024 Aug 19;14(1):19159. doi: 10.1038/s41598-024-69399-z.
The current study introduces groundbreaking insights into how organic matter (OM) of the black phosphate (RB-Ph) uniquely influences phosphorus (P) solubility during acetic acid (AA) leaching, expanding our understanding in this crucial area. To highlight such role, the OM of the RB-Ph was treated separately by different procedures including calcination at 550 ℃/4 h (CB-Ph), 30% hydrogen peroxide (HB-Ph) and intensive grinding to nano-sizes (NB-Ph). The mineralogical, chemical and morphological characteristics of phosphatic and non-phosphatic components of these phosphatic materials were carefully examined pre- and post-treatment via different techniques. The P dissolution of the precursor RB-Ph and its modified derivatives all over the applied experimental parameters traced the following trend: NB-Ph > RB-Ph > CB-Ph > HB-Ph. Intensive grinding to nanoscale resulted in amorphous components with conspicuous OM content (TOC, 0.410%), significantly enhanced P dissolution rate of NB-Ph (730-980 ppm), despite the noticeable reduction in its PO content to 22.34 wt.%. The precursor RB-Ph, thanks to its high OM content (TOC, 0.543%), also displayed a sufficient P dissolution rate (470-750 ppm) compared to the two other modified derivatives, CB-Ph (410-700 ppm) and HB-Ph (130-610 ppm). Such deep and conspicuous impact of OM on P solubility can be tied to their decomposition, releasing not only organic acids but also the adsorbed P by the OM's surficial binding sites to the solution. Finally, the optimum conditions of P leaching were attained at 2:1 acid/solid (w/w) ratio and 2 h of retention time of all investigated samples.
当前的研究对黑磷（RB-Ph）的有机质（OM）在醋酸（AA）浸出过程中如何独特地影响磷（P）的溶解度提出了开创性的见解，扩展了我们在这一关键领域的理解。为突出这种作用，RB-Ph的OM通过不同程序分别处理，包括在550℃下煅烧4小时（CB-Ph）、30%过氧化氢处理（HB-Ph）以及研磨至纳米尺寸（NB-Ph）。通过不同技术仔细检查了这些含磷材料的磷质和非磷质成分在处理前后的矿物学、化学和形态特征。在所应用的实验参数范围内，前体RB-Ph及其改性衍生物的P溶解遵循以下趋势：NB-Ph＞RB-Ph＞CB-Ph＞HB-Ph。研磨至纳米级导致形成具有显著OM含量（总有机碳，0.410%）的无定形成分，显著提高了NB-Ph的P溶解速率（730 - 980 ppm），尽管其PO含量显著降低至22.34 wt.%。前体RB-Ph由于其高OM含量（总有机碳，0.543%），与其他两种改性衍生物CB-Ph（410 - 700 ppm）和HB-Ph（130 - 610 ppm）相比，也表现出足够的P溶解速率（470 - 750 ppm）。OM对P溶解度如此深刻和显著的影响可归因于它们的分解，不仅释放了有机酸，还将OM表面结合位点吸附的P释放到溶液中。最后，所有研究样品在酸/固比为2:1（w/w）和保留时间为2小时的条件下达到了P浸出的最佳条件。
