本文選題：金的賦存狀態(tài) + 含砷黃鐵礦�。� 參考：《地質(zhì)論評(píng)》2017年05期

【摘要】：通過系統(tǒng)的顯微鏡鑒定及掃描電鏡觀察,將黔西南普安泥堡金礦床中的黃鐵礦按形貌特征劃分為6種類型,即立方體狀、草莓狀、細(xì)粒狀、粗粒狀、環(huán)帶狀及長(zhǎng)條狀黃鐵礦。黃鐵礦電子探針分析結(jié)果表明,主要載金礦物為含砷黃鐵礦(環(huán)帶狀黃鐵礦、細(xì)粒狀黃鐵礦)和毒砂。環(huán)帶狀黃鐵礦核部和環(huán)帶形成于不同的成巖、成礦階段,其核部貧Au、As,富Fe、S,屬成巖期的產(chǎn)物;環(huán)帶富Au、As,貧Fe、S,形成于主成礦期。黃鐵礦環(huán)帶中Au與As具有正對(duì)應(yīng)關(guān)系,在一定的楔形空間呈正相關(guān),高Au含量往往與中等As含量(2%~6%)相對(duì)應(yīng);而As與S呈明顯負(fù)相關(guān),說(shuō)明富砷環(huán)帶是As取代S而進(jìn)入黃鐵礦晶格所致。細(xì)粒狀黃鐵礦具有高Au、As,低Fe、S的特點(diǎn),類似于環(huán)帶狀黃鐵礦環(huán)帶部位的特征,推測(cè)富As環(huán)帶與細(xì)粒狀黃鐵礦同屬主成礦階段的產(chǎn)物。毒砂常穿插或沿含砷黃鐵礦邊緣分布,表明其形成晚于熱液期含砷黃鐵礦。因此,泥堡金礦床中載金礦物的結(jié)晶順序大致為:貧砷沉積成因黃鐵礦(核部)→迤富砷黃鐵礦環(huán)帶和細(xì)粒狀黃鐵礦→迤毒砂。電子探針點(diǎn)分析和面波普掃描顯示,Au在載金礦物含砷黃鐵礦和毒砂中具有不均勻分布的特征,根據(jù)Au的溶解度極限(Au/As 0.02)和lgw(As)—lgw(Au)圖解,推測(cè)Au主要以"不可見"固溶體(Au~(+1))形式賦存于含砷黃鐵礦和毒砂中,極少量可能為納米級(jí)自然金(Au~0)。
[Abstract]:The pyrite in Pu'an Nibao gold deposit in southwest Guizhou is divided into 6 types according to their morphological characteristics, i.e. cube, strawberry, fine grain, coarse grain, annular and long stripe pyrite. The results of electron probe analysis of pyrite indicate that the main gold bearing minerals are arsenic-bearing pyrite (annular pyrite, fine-grained pyrite) and arsenopyrite. The core and belt of annular pyrite are formed in different diagenetic stages. In the metallogenic stage, the core is rich in Au-As-rich Fe-S, which belongs to the product of diagenetic period, and the annular zone is rich in Au-As-rich and Fe-S-rich, which was formed in the main metallogenic period. In the pyrite ring zone, au and as have a positive correspondence, and there is a positive correlation between au and as in a certain wedge-shaped space. The high au content often corresponds to the middle as content, while the correlation between as and S is obviously negative. The results show that the arsenic rich ring is caused by as replacing S and entering the pyrite lattice. Fine grained pyrite is characterized by high Au2 + as and low Fe2 S, which is similar to that of annular zonal pyrite. It is inferred that the AS-rich annulus and fine granular pyrite belong to the main ore-forming stage. Arsenopyrite is often interspersed or distributed along the edge of arsenopyrite, which indicates that arsenopyrite was formed later than hydrothermal stage. Therefore, the crystallization order of the gold bearing minerals in the Nipu gold deposit is roughly: the arsenic-poor sedimentary pyrite (core) and the fine grained pyrite deposit. Electron probe point analysis (EPMA) and surface pop scanning show that au has the characteristics of uneven distribution in arsenopyrite and arsenopyrite bearing gold ore. According to the solubility limit of au (au / as 0.02) and the diagram of lgwttrium As-lgwfen (Au2), the results show that the au is distributed unevenly in the arsenopyrite and arsenopyrite containing gold ore. It is inferred that au mainly exists in arsenopyrite and arsenopyrite in the form of "invisible" solid solution, and a very small amount may be nano-scale natural gold.
【作者單位】： 貴州大學(xué)礦業(yè)學(xué)院;貴州大學(xué)資源與環(huán)境工程學(xué)院;
【基金】：國(guó)家自然基金資助項(xiàng)目(編號(hào):41072072,41503030) 貴州省科技合作計(jì)劃項(xiàng)目(編號(hào):黔科合LH字[2015]7663號(hào)) 貴州省教育廳青年科技人才成長(zhǎng)項(xiàng)目(批準(zhǔn)號(hào):黔教合KY字[2016]117) 貴州省國(guó)土資源廳公益性項(xiàng)目(黔國(guó)土資發(fā)[2015]34號(hào))的成果~~
【分類號(hào)】：P618.51
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本文編號(hào)：2045932