陕西省宁强县宽川铺磷块岩稀土矿特征初探

宽川铺磷矿为一低品位磷矿床,赋矿层位为寒武系牛蹄塘组第二岩性段第二岩性层。磷矿体主要分布在选将坪一带,选将坪以西为泥质及硅质鳞块岩,矿体平均厚1.77 m,P2O5品位11.03%~21.03%;选将坪东段为灰质磷块岩,矿层平均1.23 m,P2O5品位9.23%~15.5%。该磷矿富含稀土,选将坪以西泥质及硅质磷块岩伴生稀土(∑REE)平均品位为953.68×10^﹣6;选将坪以东灰质磷块岩偶夹硅泥质磷块岩,伴生稀土(∑REE)平均品位为869.32×10^﹣6。伴生稀土重稀土大于轻稀土,重稀土占稀土总量50%以上;以重稀土的钇(Y)为主,钇(Y)含量占稀土总量最高达48%。稀土与P2O5呈正相关关系;该矿磷块岩类型为泥质磷块岩、硅质磷块岩、灰质磷块岩,其中泥质磷块岩中稀土含量较高;对硅质磷块岩进行X衍射,发现其主要为石英和少量氟磷灰石。

CHARACTERISTICS OF RARE EARTH ORE IN PHOSPHORITE IN KUANCHUANPU AREA OF NINGQIANG COUNTY,SHAANXI PROVINCE

Kuanchuanpu phosphorite is a low-grade phosphorite deposit.The ore bearing horizon is the second lithologic layer of the second lithologic section in the Niutitang Formation of Cambrian.The phosphorus ore body is mainly distributed in Xuanjiangping area.To the west of Xuanjiangping is argillaceous and siliceous scale rock with an average thickness of 1.77 m,P2O5 grade of 11.03%~21.03%;to the east of Xuanjiangping is calcareous phosphorite with an average ore bed of 1.23 m,P2O5 grade of 9.23%~15.5%.The phosphate ore is rich in rare earth.The average grade of the associated rare earth(∑REE)in the argillaceous and siliceous phosphorite in the west of Xuanjiangping is 953.68×10^﹣6 and in the calcareous phosphorite in the east of Xuanjiang ping 869.32×10^﹣6.The content of associated heavy rare earth is larger than light rare earth,and the heavy rare earth accounts for more than 50%of the total rare earth;the heavy rare earth is mainly yttrium(y)accounting for 48%of the total rare earth.There is a positive correlation between rare earth and P2O5.The types of phosphorites in the deposit are argillaceous,siliceous and calcareous phosphorites,a mong which the content of rare earth in argillaceous phosphorites is relatively high.The siliceous phosphorites are mainly quartz and small a mount of fluorapatite detected by X-ray diffraction.