贵州织金磷矿床中离子吸附型稀土的存在及初步定量

A Review of a Preliminary Quantitative Study and Genetic Analysis for Rare Earth Elements of Ionic Adsorption State in Phosphate Ore Deposit in Zhijin,Guizhou Province

近年来研究表明贵州织金磷块岩矿床中伴生丰富的稀土主要以类质同象形式存在,其主要依据为稀土总量与磷含量的正相关性,而对独立稀土矿物与离子吸附型稀土两种赋存状态的认识目前仍然不清楚。本文通过利用电感耦合等离子体质谱(ICP-MS)稀土元素全分析、磷钼酸喹啉重量法磷分析、岩矿鉴定与实验室选矿试验等方法对该矿床中伴生稀土的赋存规律进行了研究。岩矿鉴定表明矿石中主要矿物成分为胶磷矿并含少量黏土矿物,但未发现独立的稀土矿物;磷与稀土全分析显示稀土总量及各分量都与磷含量呈正相关,从而验证并进一步表明了稀土主要以类质同象形式存在于胶磷矿中。通过研究原矿经选别后稀土与磷在精矿、尾矿和选液(尾矿水)中的分配对比及两者的含量关系来探讨稀土的赋存规律,结果显示磷仅分配于精矿和尾矿中未发生损失,而11.98%的稀土在强电解质硫酸盐的作用下从原矿中解离出来进入了选液,推断这部分稀土在原矿中未进入矿物晶格,而是呈离子态吸附于矿物表面,初步认为漫长时限与潮湿条件下的充分风化作用以及胶磷矿与黏土矿物所充当的吸附载体发挥了作用,表明织金磷矿中稀土总量的11.98%以离子吸附状态存在。综合各分析结果,织金磷矿伴生稀土各赋存状态中类质同象占主导,未发现独立稀土矿物,而离子吸附型稀土占一定的比例,故将稀土的离子吸附形式列为仅次于类质同象的第二大赋存状态。

Recent studies on rare earth elements （REEs） for the Phosphate Deposit in Zhijin, Guizhou show that the occurrence state of REEs is dominated by isomorphism on the basis of the positive correlation between ∑ REEs content and phosphorus content. However, the understanding for the independent REE minerals state and the ionic adsorption REE state is still not clear at present. Methods of Inductively Coupled Plasma-Mass Spectrometry （ICP- MS） analysis for REEs, quinoline phosphomolybdate gravimetry analysis for phosphorus, rock-mineral identification and laboratory beneficiation test have been carried out for the study of REE occurrence state in the deposit. The results from rock-mineral identification show the REE-phosphate ore are composed of collophane dominantly and a small quantity of clay minerals, but no independent REEs minerals have been observed. Element content analytical results indicate a positive correlation between ]~REEs and phosphorus, and even between each single REE and phosphorus, which confirm REEs occur in collophane as isomorphism state dominantly. The REEs distribution was studied by allocation and content correlation of REEs and phosphorus in the concentration, railings and processing solution （tailing water）. As a result, phosphorus only collects in the concentrate and tailings without any loss, while 11. 98% of ∑REEs dissociates from ore under the reaction of strong sulfate electrolyte and enters the processing solution. It indicated that this part of REEs was adsorbed on the surface of minerals instead of in mineral crystal lattice. 11.98% of REEs are ionic adsorption REEs. The complete weathering on the condition of eternity and moisture and adsorption carriers played by collophane and clay minerals contributed to the genesis of the ionic adsorption state REEs. In summary, the occurrence state of REEs hosted in the deposit is dominated by isomorphism and partly is in an ionic adsorption state and not an independent REE mineral. Therefore, ionic adsorption is the second primary occmxenee state after the isomorphism state.