A growing global population and climate change pose significant challenges to sustainable agriculture, requiring innovative approaches to fertilizer production and carbon sequestration. This study investigates the potential of thermally-treated igneous apatite from the Lac à Paul magmatic deposit (Québec, Canada) as an environmentally friendly alternative to conventional phosphate fertilizers. The research examines the physical and chemical transformations of heated apatite concentrate, focusing particularly on phosphorus release mechanisms and carbon sequestration potential. Heat treatment at 800 °C demonstrated the highest phosphorus liberation after 30 min, although concentrations remained lower than conventional fertilizers (129.8 mg/L for UQC2 versus 1171.1 mg/L for NPK 10–52-10); Scanning electron microscopy revealed the formation of etch pits on acid-attacked grains within 30 min of reaction, indicating rapid surface modification. Notably, the dissolution process exhibited early-stage incongruency favoring calcium release, with concentrations reaching 330 mg/L. This preferential calcium liberation suggests potential for CO2 sequestration through carbonate mineral formation in the soil. Although the immediate phosphorus availability from heated igneous apatite is lower than conventional fertilizers, its geochemical stability favors sustained nutrient release capabilities in the longer term. Furthermore, the low concentration of contaminants (U, Th, Cd) in igneous apatite relative to sedimentary sources makes igneous apatite particularly suitable for agricultural applications. Our findings contribute to the development of sustainable fertilizer alternatives that could simultaneously address agricultural productivity and climate change mitigation through carbon sequestration and offer insights into the intricate relationship between mineral composition and nutrient availability.

中文翻译：

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Lac à Paul 磷灰石的热预处理和不一致溶解：对磷生物利用度和碳封存的影响

不断增长的全球人口和气候变化对可持续农业构成了重大挑战，需要创新的肥料生产和碳封存方法。本研究调查了来自 Lac à Paul 岩浆矿床（加拿大魁北克）的热处理火成磷灰石作为传统磷肥的环保替代品的潜力。该研究考察了加热磷灰石精矿的物理和化学转化，特别关注磷释放机制和碳封存潜力。800 °C 热处理在 30 分钟后显示出最高的磷释放量，尽管浓度仍然低于常规肥料（UQC2 为 129.8 mg/L，而 NPK 10-52-10 为 1171.1 mg/L）;扫描电子显微镜显示，在反应后 30 分钟内在酸侵蚀的晶粒上形成蚀刻坑，表明表面改性迅速。值得注意的是，溶出过程表现出有利于钙释放的早期不一致，浓度达到 330 mg/L。这种优先的钙释放表明，通过土壤中碳酸盐矿物的形成，有可能封存 CO2。尽管加热火成磷灰石的即时磷可用性低于传统肥料，但其地球化学稳定性有利于长期持续的养分释放能力。此外，相对于沉积源，火成磷灰石中的污染物浓度（U、Th、Cd）浓度较低，这使得火成磷灰石特别适合农业应用。 我们的研究结果有助于开发可持续的肥料替代品，这些替代品可以通过碳封存同时解决农业生产力和缓解气候变化问题，并为矿物成分和养分可用性之间的复杂关系提供见解。