Recovery of Phosphorus from Modified Steelmaking Slag with High P2O5 Content via Leaching and Precipitation
Recovery of Phosphorus from Modified Steelmaking Slag with High P2O5 Content via Leaching and Precipitation
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浸出沉淀法从高P2O5含量的改性炼钢渣中回收磷
DOI：
10.2355/isijinternational.isijint-2017-454
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
S. Kitamura
中科院分区：
文献类型：
--
作者：
Chuan;Xu Gao;S. Ueda,;S. Kitamura
：炼钢炉渣中所含的P被认为是潜在的磷源，特别是对于利用高磷铁矿石产生的高P 2 O 5 含量的炉渣。如果能够从炉渣中有效地提取磷，所得的磷可以用作磷肥。此外，剩余的炉渣可以在炼钢过程中回收利用。与其他相相比，炉渣中的P凝聚型C 2 S-C 3 P固溶体更易溶于水；因此，采用选择性浸出从高P 2 O 5 含量的炉渣中回收P。本研究研究了K 2 O改性对柠檬酸溶液中磷溶解的影响，并随后探索了通过沉淀从渗滤液中提取磷酸盐产品的工艺。结果表明，K 2 O改性促进了固溶体的溶解，导致P的溶解率更高。通过改性，大部分固溶体在pH 6时溶解，其他相保留在残渣中，表明P发生了更好的选择性浸出。随着pH值降低，P和Fe的溶解率均增加。在pH 5下浸出后，获得具有较高Fe 2 O 3 含量和较低P 2 O 5 含量的残渣。当浸出液的pH值升高时，水溶液中溶解的P就会沉淀出来。通过分离和煅烧，得到P 2 O 5 含量为30％的磷酸盐产品，具有用作磷肥的潜力。
: The P contained in steelmaking slag is regarded as a potential phosphate source, especially with regard to slag with high P 2 O 5 content, which is generated from the utilization of high P iron ores. If P can be effi-ciently extracted from slag, the obtained P can be used as a phosphate fertilizer. Moreover, the remaining slag can be recycled inside the steelmaking process. Compared with other phases, the P-condensed C 2 S– C 3 P solid solution in slag is more easily dissolved in water; therefore, selective leaching was applied to recover P from slag with high P 2 O 5 content. In this study, the effect of K 2 O modification on P dissolution in the citric acid solution was investigated, and sub-sequently, a process for extracting phosphate product from the leachate, via precipitation, was explored. It was determined that K 2 O modification promoted dissolution of the solid solution, resulting in a higher dissolution ratio of P. By modification, the majority of the solid solution was dissolved at pH 6, and other phases remained in residue, indicating that a better selective leaching of P occurred. As the pH decreased, the dissolution ratios of both P and Fe increased. Following leaching at pH 5, a residue with a higher Fe 2 O 3 content and lower P 2 O 5 content was obtained. When the pH of the leachate increased, the dissolved P in the aqueous solution was precipitated. Through separation and calci-nation, a phosphate product with a P 2 O 5 content of 30% was obtained, which has the potential to be used as a phosphate fertilizer.