氯化铵焙烧法分解氟碳铈精矿制备晶型碳酸稀土的研究

Preparing Crystal RE_2(CO_3)_3 from the Leaching Solution of Decomposed Bastnasite Concentrate by NH\-4Cl Roasting method

采用脱氟剂将氟碳铈精矿中的氟转化为水溶性氟洗去，再用氯化铵焙烧法分解经预脱氟的氟碳铈精矿，直接用水浸取稀土。考察了反应温度、时间、氯化铵用量及脱氟剂用量对该矿稀土提取率的影响，脱氟精矿在焙烧温度４８０℃，焙烧时间１．５ｈ，氯化剂／矿重＝ ２．０ 时，稀土提取收率达８４．３％ 。其氯化选择性高，浸出液中Ｆｅ、Ａｌ、Ｓｉ等非稀土杂质分别为稀土的０．１０％ 、０．００５％ 和０．０１６％ ，经碳酸氢铵沉淀，获得了晶型碳酸稀土（折算稀土氧化物纯度９２．０７％ ）产品。

A novel process was put forward to recover RE with NH 4Cl roasting method from bastnasite concentrate.The effects of eliminating fluorine,reaction temperature,NH 4Cl amount and reacting time on recovering RE are determined.RE leaching ratio reach 84.3% for the bastnasite concentrate stripped 80% fluoring by roasting 1.5h at 480℃,chlorinating agent/ore =2.0.The chlorinating process possess high selectivity,little impurities of Fe,Al and Si et al was dissolved in the leaching solution.The Fe,Al and Si content of leaching solution are 0.10%,0.005% and 0.016% respectively.Further precipitating the leaching solution by NH\-4HCO\-3,a crystal RE\-2(CO\-3)\-3·7H\-2O product with 52.13% REO content and 92.07% purity was prepared.