Analysis of the Occurrence of Platinum-Palladium and Precipitation Mechanism by SEM and EPMA in the Ni-Cu Sulphide Deposits from Yangliupin, Sichuan Province, China
-
摘要:
本文利用电子探针和配备能谱分析功能的扫描电镜对四川杨柳坪镍-铜硫化物矿床中铂钯的赋存状态进行了研究。结果表明, 铂以独立矿物相砷铂矿和自然铂存在; 钯以碲化物、碲铋化物、碲锑化物、锑化物及自然钯独立矿物相存在, 也以类质同象形式分布在碲镍矿中(钯含量约10%), 另外还以锑铋钯碲矿、六方锑碲钯矿、碲钯矿独立矿物相存, 并以类质同象形式分布在Vavrinite(钯含量5%)和砷铂矿(钯含量1%~5%)中。杨柳坪矿床中铂钯元素沉淀与贱金属矿物(BMS)及晚期热液蚀变矿物蛇纹石、方解石密切相关, 其沉淀经历了3个阶段:① 早期高温阶段(1200~900℃), 铂钯元素沉淀并包裹在BMS中; ② 中期中高温阶段(650~250℃), 分离结晶作用使铂钯元素沉淀并分布BMS矿物的边部, 同时该阶段热液来源的铂钯元素沉淀于BMS粒间; ③ 晚期热液蚀变阶段(500~300℃), 热液蚀变作用引起铂钯元素沉淀在蚀变矿物中或嵌布在BMS裂隙。本文研究成果为认识该矿床及同类型镍-铜硫化物矿床的铂钯成矿过程提供了新的依据。
Abstract:The occurrence of Pt and Pd in Cu-Ni suphide deposits from Yangliupin, Sichuan Province has been studied successfully by Electron Probe Microscope (EPMA) and Scanning Electron Microscope (SEM) with energy analysis function. The result showed that Pt existing in the form of sperrylite and native platinium, and Pd was either mainly in the form of individual minerals such as testibiopalladite and hexatestibiopanickelite, or in the form of hexastibiopalladinite, michenerite and merenskyite. Pd was also found as isomorphism form in the Vavrinite (Pd 5%), sperrylite (Pd 1%-5%) and melonite (Pd 10%) which was initially found in the deposit. The precipitation of Pt and Pd was closely related to base metal sulfide (BMS) and altered minerals such as serpentine and calcite. The process can be described as follows: in the first stage with high temperature (1200-900℃), Pt and Pd was precipitated and then included in BMS; in the second stage with high-moderate temperature (650-250℃), Pt and Pd was precipitated on the side or in the crack of BMS with fractional crystallization or hydrothermal function respectively; and in the last stage with the temperature of 500-300℃, Pt and Pd was precipitated in the alteration minerals or in the crack of BMS by reason of alteration. The analysis results provide the scientic basis for other Ni-Cu sulfide of the same type.
-
-
表 1 矿石中铂族元素的含量
Table 1. The conponents of platinium gorup elements in ore
矿石类型 Au
(10-6)Ag
(10-6)Pt
(10-9)Pd
(10-9)Os
(10-9)Ir
(10-9)Rh
(10-9)Ru
(10-9)杨柳坪浸染状 2.12 0.12 198 456 16.4 12 15.9 31.8 杨柳坪浸染状 0.18 0.002 22.7 32.2 6.28 3.43 16 8.3 协作坪浸染状 1.44 0.08 200 403 13.1 16.1 19.2 34.5 正子岩窝浸染状 0.24 0.02 8.94 8.65 2.22 0.69 20.1 0.4 正子岩窝浸染状 1.58 0.06 211 326 5.96 3.26 6.65 8.6 打枪岩窝块状 15.1 0.06 1670 4010 23.3 28.5 70.7 62.7 打枪岩窝块状 2.86 0.19 487 788 21.4 24.4 36.5 55.2 正子岩窝块状 2.22 0.08 430 715 11.4 15 24 28.1 平均值 3.22 0.08 403.46 842.36 12.51 12.92 26.13 28.7 注:测试单位为四川省地矿局冶金地质研究所。 表 2 铂矿物单矿物化学成分
Table 2. Chemical composition of platinum minerals
矿物名称
及编号元素含量(%) S Fe Ni As Sb Pt 总量 砷铂矿
(ZZYW2-
2-02)0.374 2.048 0.000 44.085 0.015 52.446 98.968 0.440 1.836 0.000 43.323 0.014 52.507 98.120 0.863 1.501 0.000 43.503 0.412 52.384 98.663 0.344 2.190 0.059 43.336 0.606 51.986 98.521 0.277 3.504 0.000 42.218 0.749 52.314 99.062 0.261 1.218 0.020 42.371 2.259 51.885 98.014 0.234 1.211 0.058 43.492 1.366 52.487 98.848 0.257 1.291 0.000 43.062 1.406 52.496 98.512 0.218 2.177 0.032 42.823 0.577 52.430 98.257 砷铂矿
(ZZYW2-
2-05)0.255 1.437 0.134 41.376 3.145 51.670 98.017 0.261 1.456 0.116 42.660 3.167 52.515 100.175 0.331 1.916 0.022 42.219 3.410 51.546 99.444 0.332 1.995 0.031 42.228 3.454 51.360 99.400 0.335 1.910 0.024 42.123 2.112 51.703 98.207 0.165 1.321 0.062 41.670 3.421 51.496 98.135 0.178 1.234 0.121 42.525 3.880 52.176 100.114 0.340 1.375 0.081 43.163 1.973 51.085 98.017 0.356 1.273 0.054 41.866 2.606 51.847 98.002 0.457 1.370 0.074 41.930 2.963 52.249 99.043 0.450 1.727 0.061 42.205 1.337 52.385 98.165 0.279 1.292 0.076 42.477 3.009 51.765 98.898 0.234 1.326 0.072 42.242 3.143 52.506 99.523 砷铂矿
(ZZYW2-
2-16)0.429 1.238 0.938 43.526 1.201 50.753 98.085 0.573 1.094 1.237 43.673 0.657 52.759 99.993 1.097 1.220 1.079 42.406 1.153 53.382 100.337 1.159 1.039 0.799 41.910 0.630 53.567 99.104
自然铂
ZZYW2-
2-16- 3.21 1.10 1.24 - 94.45 100.00
(能谱)1.49 3.65 - - - 94.85 100.00
(能谱)1.43 3.54 0.69 - - 94.33 100.00
(能谱)注:除标注能谱数据外,单矿物成分均为电子探针成分分析数据,能谱数据经过归一化处理,以下各表成分数据与此相同。分析单位:国土资源部成都地质矿产研究所。 -
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] 罗辅勋, 朱廷国, 郭瑞. 四川丹巴地区铂矿评价预查地质报告[R]. 四川省地质调查研究所, 2001.
Lu F X, Zhu Y G, Guo R. The Geological Report of Platinum Mineral Preinspection Assessment in Danba County, Sichuan[R]. Geological Survey and Research Institute of Sichuan Province, 2001.
[13] [14] [15] [16] Zientek M L, Oscarson R L. Textural Association of Platinum-group Elements from the J-M Reef, Stillwater Complex, Montana[R]. U. S. Geological Survey, 1987, Circle. 995.
[17] [18] [19] doi: 10.1180/minmag
[20] [21] [22] [23] doi: 10.1139/e17-031
[24] [25] [26] [27] -