研究生知识库

贵州织金戈仲武组（∈1gz）磷矿富集大量稀土，但是磷块岩中稀土富集特征以及稀土经济指标等问题尚不清楚。本文以贵州织金不同稀土含量区间（<262ppm、262-527ppm、527-761ppm、>761ppm）的磷块岩为研究对象，主要认识如下：（1） 因子分析表明低稀土含量（<527ppm）的磷块岩REE、Y在磷块岩形成过程中富集，高稀土含量（>527ppm）的磷块岩Y存在与REE不一致的富集过程。（2） 热水中富集的元素（Ag、As、Sb等）并没有随着磷块岩中REE的富集而逐渐富集以及磷块岩稀土配分Eu无异常，表明稀土富集过程中可能无热水作用参与。这与因子分析中热水元素（As、Sb、Ag等）与稀土富集处于不同因子结论一致。（3） 地史时期具有更高稀土含量的“老磷块岩”普遍存在重稀土亏损的特征。（La/Sm）N-SmN、（Gd/Yb）N-YbN散点图显示MREE富集是稀土在富集过程中稀土发生分异的结果。V/（V+Ni）、V/Cr比值以及Ce负异常表明磷块岩形成于氧化环境，但V/（V+Ni）、V/Cr比值以及Ce负异与稀土含量无相关性，因此认为海水的氧化环境不是控制稀土富集的决定因素。控制稀土富集的因素可能与成岩作用以及风化作用有关。（4） 通过圈定磷块岩中稀土富集带，发现稀土主要富集在戈仲武组中下部位。初步经济指标计算得出磷块岩中稀土平均最低工业品位推荐值为0.585%，边界品位推荐值为0.293%。

A large amount of rare earth is enriched in zhijin phosphorites of Gezhongwu Formation(∈1gz) Guizhou province, but the REE enrichment characteristics and rare earth economic indicators in phosphorites are still unclear. In this paper, the phosphorites with different rare earth content ranges(<262ppm, 262-527ppm, 527-761ppm, >761ppm) in zhijin, guizhou province are taken as the research objects. The main understandings are as follows:（1） factor analysis shows that REE and Y of phosphorites with low rare earth content (<527ppm) were enriched in the formation process of phosphorites, while Y of phosphorites with high rare earth content(>527ppm) had a enrichment process inconsistent with REE.（2） The elements (Ag, As, Sb) enriched in hot water were not gradually enriched along with REE enrichment in phosphorites and there are no Eu anomaly in phosphorites, indicating that rare earth enrichment may be no hot water in the process of participation. This is consistent with the conclusion that As, Sb, Ag and other hot water elements are enriched by different factors in factor analysis. This is consistent with the conclusion that the hot water elements (As, Sb, Ag, etc.) and rare earth enrichment are in different factors in factor analysis.（3） In the geological history period, "old phosphorites " with higher REE content generally has the characteristics of heavy rare earth depletion. (La/Sm)N-SmN, (Gd/Yb)N-YbN scatter diagrams show that MREE enrichment is the result of rare earth differentiation during the enrichment process. V/(V+Ni), V/Cr ratios and negative Ce anomaly indicate that the phosphorite was formed in an oxidizing environment, but V/(V+Ni), V/Cr ratios and negative Ce anomaly have no correlation with rare earth content. Therefore, it is believed that the oxidizing environment of seawater is not the determining factor for the control of rare earth enrichment. The factors controlling rare earth enrichment are related to diagenesis and weathering.（4） It is found that the rare earth is mainly concentrated in the middle and lower part of the Gezhongwu Formation by delineating the rare earth enrichment zone in phosphorites. According to the preliminary economic indicators calculation, the recommended value of mean minimum industrial grade of REE in phosphorites is 0.585%, and the recommended value of boundary grade is 0.293%.