Sun Jiangang, Xiu Yi-Fan, Huang Kai, Yu Jin-Tao, Alam Shafiq, Zhu Hong-Min, Guo Zhan-Cheng
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing Xueyuan Rd.30 Haidian District 100083 Beijing China
State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing Xueyuan Rd.30 Haidian District 100083 Beijing China
RSC Adv. 2018 Jun 19;8(40):22276-22285. doi: 10.1039/c8ra03203c.
Dephosphorisation of iron ore is an important challenge to the sustainable development of iron-making industry. Hydrometallurgical processing is quite effective in the reduction of phosphorus level from iron ores, where dilute sulfuric acid is commonly chosen as the lixiviant due to its prominent cost-effectiveness. A cheap and effective biosorbent synthesized from garlic peel was proposed in present study to recover phosphorus selectively from acid leach liquor directly under acidic conditions near pH 1-2, allowing high purity phosphorus to be recovered and the residual acid to be recycled for the next round of leaching. This proposal would sharply reduce the dephosphorisation costs of iron ore. Various batch experiments were carried out under different conditions including varying pH, contact time, adsorbent dosages, and metal ion concentration to identify the optimal adsorption parameters for the model solutions. Results showed that the optimal pH for phosphate adsorption was around 1.5 and adsorption equilibrium was attained in 240 min, and the maximum adsorption capacity for phosphate was 1.40 mmol g and 0.81 mmol g at equilibrium pH of 1.5 and 6.5, respectively. A NaOH solution was effective to elute the adsorbed phosphate, and the eluted solution contained mainly NaPO and NaOH. Recovery of phosphorus from the iron ore leach liquor by the garlic peel adsorbent was quite effective, and the adsorption efficiency could retain 85% of the original adsorption capability even after five cycles of adsorption and desorption. In summary, the Zr-loaded garlic peel appears a potential low-cost and effective adsorbent for phosphate recovery from the acid leach liquor of high phosphorus iron ore.
铁矿石脱磷是炼铁工业可持续发展面临的一项重要挑战。湿法冶金工艺在降低铁矿石磷含量方面相当有效，由于其显著的成本效益，稀硫酸通常被选作浸出剂。本研究提出了一种由蒜皮合成的廉价且有效的生物吸附剂，用于在pH值接近1 - 2的酸性条件下直接从酸性浸出液中选择性回收磷，从而能够回收高纯度的磷，并将剩余的酸循环用于下一轮浸出。这一方案将大幅降低铁矿石的脱磷成本。在不同条件下进行了各种批次实验，包括改变pH值、接触时间、吸附剂用量和金属离子浓度，以确定模型溶液的最佳吸附参数。结果表明，磷酸盐吸附的最佳pH值约为1.5，240分钟达到吸附平衡，在平衡pH值为1.5和6.5时，磷酸盐的最大吸附容量分别为1.40 mmol/g和0.81 mmol/g。NaOH溶液能有效洗脱吸附的磷酸盐，洗脱液主要含有NaPO和NaOH。用蒜皮吸附剂从铁矿石浸出液中回收磷效果显著，即使经过五个吸附和解吸循环，吸附效率仍能保持原始吸附能力的85%。综上所述，负载锆的蒜皮似乎是一种从高磷铁矿石酸性浸出液中回收磷的潜在低成本且有效的吸附剂。
