We studied yttrium extraction from untreated zircon sand processing waste tailings. Xenotime mineral as the rare earth element source with an abundance of yttrium (REY) was detected in sufficient grade for extraction. As much as 9.03% yttrium exists in zircon tailings (analysed by X-ray fluorescence spectrometry). The presence of yttrium was confirmed by X-ray diffractometry in xenotime minerals, which are yttrium carriers (Y-PO 4 ). The purpose of this research was to determine the effect of leaching conditions on yttrium recovery from zircon sand after alkaline fusion treatment. Alkaline fusion was chosen to decompose phosphate into hydroxide in the xenotime mineral, which will reduce further required hydrometallurgical processing. Alkaline fusion was carried out for 3 h at 450 °C, with a ratio of sodium hydroxide to zircon tailings sand of ~ 1:1. The alkaline fusion product was leached with water, followed by hydrochloric acid treatment to leach the yttrium. Yttrium recovery reached 87% under optimum conditions (60 °C, 1 M HCl, and solid-to-liquid ratio = 1/10 for 7.5 min). A suitable model for yttrium dissolution with hydrochloric acid was diffusion through a solid particle ash layer. The calculated activation energy (E A ) for this model was 20.21 kJ/mol.

中文翻译：

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锆石尾矿碱熔解钇的动力学

我们研究了从未处理的锆英砂加工废料尾矿中提取钇。作为稀土元素来源的磷钇矿矿物中含有丰富的钇 (REY)，被检测到具有足够的提取品位。锆石尾矿中存在多达 9.03% 的钇（通过 X 射线荧光光谱法分析）。钇的存在通过 X 射线衍射法在磷钇矿矿物中得到证实，磷钇矿是钇载体 (Y-PO 4 )。本研究的目的是确定浸出条件对碱熔处理后锆英砂中钇回收率的影响。选择碱熔法将磷钇矿矿物中的磷酸盐分解为氢氧化物，这将减少进一步需要的湿法冶金处理。碱熔在 450°C 下进行 3 小时，氢氧化钠与锆石尾矿砂的比例为~1：1、碱熔产物用水浸出，然后用盐酸处理浸出钇。在最佳条件下（60 °C，1 M HCl，固液比 = 1/10，7.5 分钟），钇回收率达到 87%。用盐酸溶解钇的合适模型是通过固体颗粒灰层扩散。该模型的计算活化能 (EA) 为 20.21 kJ/mol。