Abstract Rare earth elements comprise of lanthanides plus yttrium and scandium. They have several applications and are produced by a limited number of countries. Brazil has an estimated reserve of 22 million metric tons and most of the minerals are associated with phosphate. In the fertilizer industry, ores containing rare earth elements are combined with phosphates, fluorides, silica, limestone, titanium and gypsum. As a result, rare earth oxides (REOs) are lost with sterile dump and mining waste or are applied to the soil together with fertilizers. In this scenario, the composition and granulometry of raw and sterile materials from a phosphate producing unit were evaluated. Considering the concentration of REOs, equal to 1.56 wt% in the Catalao (GO) phosphate concentrate and the increase in concentration with the decrease in size, the objective of the present work was to separate the fraction smaller than 25 μm with a new mini- hydrocyclone. The variables such as cone angle, length of the cylindrical region, underflow orifice diameter and feed pressure influenced the following responses: capacity, underflow- to- throughput ratio, total efficiency and concentration of REOs in the overflow stream. The separator capacity was found to range from 881.5 to 1449.0 kg/h while the underflow-to-throughput ratio was between 9 and 40% and the total separation efficiency remained at around 96%. The lowest concentration of rare earth oxides obtained in the overflow stream was 79.5% higher than the concentration in the feed, corroborating the choice of hydrocyclone as a method of concentration of REOs.

中文翻译：

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水力旋流器在含稀土元素磷酸盐精矿物理处理中的应用

摘要 稀土元素包括镧系元素、钇和钪。它们有多种应用，由数量有限的国家生产。巴西的储量估计为 2200 万吨，大部分矿产与磷酸盐有关。在化肥工业中，含有稀土元素的矿石与磷酸盐、氟化物、二氧化硅、石灰石、钛和石膏结合。因此，稀土氧化物 (REO) 会随无菌垃圾场和采矿废物一起流失，或者与肥料一起施用于土壤。在这种情况下，对来自磷酸盐生产单元的原材料和无菌材料的组成和粒度进行了评估。考虑到 REOs 的浓度，在 Catalao (GO) 磷酸盐精矿中等于 1.56 wt%，并且浓度随着尺寸的减小而增加，目前工作的目标是用新的微型水力旋流器分离小于 25 μm 的部分。诸如锥角、圆柱形区域长度、底流孔口直径和进料压力等变量影响以下响应：容量、底流与吞吐量比、总效率和溢流中 REO 的浓度。发现分离器容量范围为 881.5 至 1449.0 kg/h，而底流与通过量之比为 9 至 40%，总分离效率保持在 96% 左右。在溢流中获得的稀土氧化物的最低浓度比进料中的浓度高 79.5%，证实了选择水力旋流器作为浓缩稀土氧化物的方法。