Abstract

Calcium silicates with nanosized needle-like structure have been obtained from phosphorite by hydrothermal synthesis. Phosphorus is recovered from phosphorite as sodium phosphate solution under conditions of autoclave treatment of phosphorite with alkaline solution in the presence of silicon dioxide at 250°C. This approach enables involvement of low-phosphorus raw materials into non-waste processing owing to the synthesis of calcium silicates suitable in many branches of industry. Thus prepared phosphate solutions are applicable in agriculture and, after appropriate purification, in food industry. Hydrothermal synthesis conditions have been determined: temperature of 250–300°C, leaching time of 3 h, and NaOH concentration of 150 kg/m³.

中文翻译：

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水热合成硅酸钙从磷矿石中回收磷

 抽象的

通过水热合成从磷矿中获得具有纳米针状结构的硅酸钙。在二氧化硅存在下，在250℃下用碱性溶液对磷矿石进行高压釜处理的条件下，以磷酸钠溶液的形式从磷矿石中回收磷。由于合成了适用于许多工业领域的硅酸钙，这种方法使得低磷原材料能够参与无废物处理。由此制备的磷酸盐溶液可用于农业，并且在适当纯化后可用于食品工业。确定了水热合成条件：温度250~300℃，浸出时间3 h，NaOH浓度150 kg/m ³ 。