甘肃金川铜镍硫化物矿床中含钴矿物组合与钴元素赋存状态  

Characteristics of Cobalt-bearing Minerals and Its Occurrence Patterns in Jinchuan Cu-Ni Sulfide Deposit of Gansu,China

作　　者：高亚林 焦建刚[3] 何敏[1,2] 赵毕文 陆斌刚 周涛[2] GAO Ya-lin;JIAO Jian-gang;HE Min;ZHAO Bi-wen;LU Bin-gang;ZHOU Tao(National Key Laboratory of Ni&Co Associated Minerals Resources Development and Comprehensive Utilization,Jinchang 737100,Gansu,China;Jinchuan Group Co.,Ltd.,Jinchang 737100,Gansu,China;Xi'an Key Laboratory for Mineralization and Efficient Utilization of Critical Metals,Chang'an University,Xi'an 710054,Shaanxi,China)

机构地区：[1]镍钴共伴生资源开发与综合利用全国重点实验室,甘肃金昌737100 [2]金川集团股份有限公司,甘肃金昌737100 [3]长安大学西安市关键金属成矿与高效利用重点实验室,陕西西安710054

出　　处：《地球科学与环境学报》2023年第5期1080-1093,共14页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(42330807,92162213);教育部重点科研平台开放基金项目(300102273503);镍钴共伴生资源开发与综合利用全国重点实验室项目(JKXGNZ26Z202101)。

摘　　要：作为我国最大、世界第三的金川铜镍(钴)硫化物矿床,其钴储量占全国总储量的30%以上,明确金川矿床矿石中含钴矿物特征及其超常富集的赋存规律,对于关键金属元素成矿动力学研究的核心科学问题——超常富集成矿过程与驱动机制有着重大意义。从金川矿床形成及影响矿化特征等方面来探讨其中钴元素成矿机制与成矿规律,同时通过包括元素共生分异规律、共伴生富集成矿的主控因素来研究钴元素赋存状态。结果表明:金川矿床矿石中独立的钴及含钴矿物极少,多为硫化钴镍矿物和硫砷化钴镍矿物,主要为辉钴镍矿、辉砷镍钴矿、硫砷钴镍矿、辉砷钴镍矿,其中辉砷镍钴矿与辉砷钴镍矿常与磁黄铁矿或镍黄铁矿连生,尤其大部分存在于镍黄铁矿和镍铜微晶中,暗示其成因与岩浆作用有关;Co主要分散于硫化矿物组(约占90.30%)中,其中约97%分散于镍黄铁矿和镍铜微晶中;约2.85%的Co分散于羟镁硫化矿物组中,其中44.46%分布于墨铜矿中;6.51%的Co分散于脉石矿物组中,其中约73%分散于蛇纹石中。在镍黄铁矿中Ni/Co值约为44.00,镍铜微晶中Ni/Co值约为2.00;在磁铁矿中Ni/Co值约为11.00;在金川矿床分布最广泛的蛇纹石等脉石矿物中,其Ni/Co值约为24.00;矿石中Co含量与Ni含量有一定的线性关系,Ni与Co都主要赋存于镍黄铁矿中,表明二者之间存在密切成因联系。As the largest magmatic Cu-Ni(-Co) sulfide deposit in China and the third largest in the world,the reserves of Co in Jinchuan deposit account for more than 30% of the total reserves in China.It is of great significance to study the characteristics of Co-bearing minerals of ores in Jinchuan deposit and their extraordinary enrichment occurrence regularity for the core scientific problem of metallogenic kinetics of key metal elements,which is extraordinary enrichment metallogenic process and its driving mechanism.The metallogenic mechanism and regularity of Co were discussed by studying the formation and mineralization characteristics of Jinchuan deposit.At the same time,the occurrence state of Co was studied on the main controlling factors of element symbiotic-differentiation and co-associated enrichment mineralization.The results show that there are very few independent Co and Co-bearing minerals of ores in Jinchuan deposit,most of which are Co-Ni sulfide minerals and sulfur-arsenic Co-Ni minerals,mainly including cobalt polydymite,Co-bearing nickelglance,nickel cobaltite and Co-Ni gersdorffite.Among them,nickel cobaltite and Co-Ni gersdorffite are often associated with pyrrhotite or pentlandite,especially most of them exist in pentlandite and Ni-Cu microcrystallites,suggesting that their genesis is also related to magmatism.Co is mainly dispersed in sulfide mineral group(about 90.30%),of which 97% is dispersed in pentlandite and Ni-Cu microcrystallites.About 2.85% of them are dispersed in hydroxymagnesium sulfide mineral group,of which 44.46% is distributed in vallerite;6.51% is dispersed in gangue mineral group,of which about 73% is dispersed in serpentine.The Ni/Co ratio in pentlandite is about 44.00,and that in Ni-Cu microcrystallites is about 2.00.The Ni/Co ratio in magnetite is about 11.00;among the most widely distributed gangue minerals such as serpentine in Jinchuan deposit,the Ni/Co ratio is about 24.00.There is a certain linear relationship between the contents of Co and Ni of ores.Both Co and Ni mainly

关 键 词：铜镍(钴)硫化物矿床 含钴矿物 富集规律 矿物特征 镍黄铁矿 磁黄铁矿 赋存规律 甘肃 

分 类 号：P618.62[天文地球—矿床学]