Ryszko Urszula, Rusek Piotr, Kołodyńska Dorota
Analytical Laboratory, Łukasiewicz Research Network-New Chemical Syntheses Institute, al. Tysiąclecia Państwa Polskiego 13a, 24-110 Puławy, Poland.
Fertilizers Research Group, Łukasiewicz Research Network-New Chemical Syntheses Institute, al. Tysiąclecia Państwa Polskiego 13a, 24-110 Puławy, Poland.
Materials (Basel). 2023 Jan 13;16(2):793. doi: 10.3390/ma16020793.
Phosphate rocks (PRs) play a crucial role in ensuring the availability of phosphorous for the world's food needs. PRs are used to manufacture phosphoric acid in the wet process as well as P-fertilizers. The chemical and mineralogical compositions of PRs from Djebel Onk (Algeria), Khneifiss (Syria), Negev (Israel), Bou Craa (Morocco), and Khouribga (Morocco) are discussed in this study. PRs were characterized by inductively coupled plasma optical emission spectrometry (ICP-OES), cold vapor atomic absorption spectrometry (CVAAS), ion chromatography (IC), and X-ray diffraction (XRD), as well as gravimetric and potentiometric methods. All PRs were mainly composed of CaO, PO, SiO, F, SO, NaO, MgO, AlO, FeO, SrO, and KO at the level of wt.%. The PO content accounted for 28.7-31.2%, which indicates that these are beneficial rocks to a marketable product. The degree of PR purity expressed by the minor elements ratio index (MER index) varied from 2.46% to 10.4%, and the CaO/PO weight ratio from 1.6 to 1.9. In addition, the occurrence of trace elements such as As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Ti, V, U, and Zn, as well as Cr(VI) and Cl ions at the level of mg∙kg was found. Since PRs will be used to produce P-fertilizers, their composition was compared with the regulatory parameters set up by EU Regulation 2019/1009 related to the heavy metals (As, Cd, Pb, Ni, Hg, Cu, Zn) and Cr(VI) contents in inorganic fertilizers. The heavy metals and Cr(VI) content in all PRs did not exceed the limit values. XRD analysis revealed that fluorapatite, hydroxyapatite, carbonate fluorapatite, and carbonate hydroxyapatite were the dominant minerals. The accuracy and precision of the used methods were evaluated by analysis of standard reference materials (SRM) for Western Phosphate Rock (NIST 694). The recovery was 85.3% for U and 109% for KO, and the RSD ranged from 0.67% to 12.8%.
磷矿石在确保全球粮食供应所需的磷的可获取性方面发挥着关键作用。磷矿石用于湿法生产磷酸以及磷肥。本研究讨论了来自阿尔及利亚杰贝勒翁克、叙利亚赫奈菲斯、以色列内盖夫、摩洛哥布克拉和摩洛哥胡里卜加的磷矿石的化学和矿物组成。通过电感耦合等离子体发射光谱法（ICP - OES）、冷蒸气原子吸收光谱法（CVAAS）、离子色谱法（IC）、X射线衍射法（XRD）以及重量法和电位滴定法对磷矿石进行了表征。所有磷矿石的主要成分按重量百分比计主要为CaO、PO、SiO、F、SO、NaO、MgO、AlO、FeO、SrO和KO。PO含量占28.7 - 31.2%，这表明这些是适合制成可销售产品的矿石。用微量元素比率指数（MER指数）表示的磷矿石纯度程度在2.46%至10.4%之间变化，CaO/PO重量比在1.6至1.9之间。此外，还发现了毫克/千克水平的痕量元素，如As、Cd、Cr、Cu、Hg、Mn、Ni、Pb、Ti、V、U和Zn，以及Cr(VI)和Cl离子。由于磷矿石将用于生产磷肥，将其成分与欧盟法规2019/1009设定的与无机肥料中重金属（As、Cd、Pb、Ni、Hg、Cu、Zn）和Cr(VI)含量相关的监管参数进行了比较。所有磷矿石中的重金属和Cr(VI)含量均未超过限值。XRD分析表明，氟磷灰石、羟基磷灰石、碳酸氟磷灰石和碳酸羟基磷灰石是主要矿物。通过分析西部磷矿石标准参考物质（SRM，NIST 694）评估了所用方法的准确性和精密度。U的回收率为85.3%，KO的回收率为109%，相对标准偏差（RSD）在0.67%至12.8%之间。
