【摘要】：我國鋁土礦資源相對匱乏,但需求量大。澳大利亞鋁土礦資源豐富,是我國鋁土礦進口主要國家之一。Darling Range地區(qū)為澳大利亞鋁土礦主產(chǎn)地之一,了解該區(qū)的鋁土礦成礦特征將有助于我國企業(yè)走出去在該地區(qū)或相似地區(qū)找礦提供依據(jù)。Darling Range位于西澳大利亞的伊爾崗克拉通,該區(qū)鋁土礦以紅土型為主,鋁土礦的顯著特點是品位較低,鐵、硅含量高,但對鋁土礦冶煉有害的可溶性硅含量低,資源潛力巨大。鋁土礦產(chǎn)于紅土層中,厚度受后期剝蝕作用控制。紅土剖面從上到下依次分為覆蓋層、硬殼、碎屑層和底部粘土層。覆蓋層以砂礫為主,具有經(jīng)濟意義的鋁土礦主要集中在碎屑層和硬殼中,底部粘土層則阻止鋁土礦繼續(xù)向下運移。鋁土礦中的礦石礦物主要是三水鋁石,也有少量一水軟鋁石,主要由花崗巖或基性巖(如輝綠巖、綠巖)中的長石經(jīng)過風化淋濾形成。Darling Range地區(qū)鋁土礦根據(jù)基巖的種類可分為花崗巖類鋁土礦和鎂鐵質類鋁土礦,分別以Jarrahdale鋁土礦礦床和Mount Saddleback鋁土礦礦床為代表。鋁土礦的成礦主要受氣候、母巖、地貌、排水和植被等因素控制。氣候主要通過控制氣溫和降水影響紅土化作用的進行;母巖通過自身的物理化學性質和礦物組成控制鋁土礦的形成;地貌和排水影響鋁土礦的風化速度;植被的作用既保證了土壤風化淋濾所需的滲透性,又降低了外部因素對土壤的侵蝕速率。在各種成礦因素的綜合作用下,經(jīng)過漫長的時間演化最終形成了紅土型鋁土礦。
[Abstract]:The bauxite resources in our country are relatively scarce, but the demand is large. Australia is rich in bauxite resources and is one of the main import countries of bauxite in China. Darling Range is one of the main producing areas of bauxite in Australia. The obvious characteristics of bauxite are low grade, high iron and silicon content, but low soluble silicon content harmful to bauxite smelting, and great resource potential. Bauxite occurs in laterite and its thickness is controlled by late denudation. The laterite profile is divided into overburden layer, hard crust layer, clastic layer and bottom clay layer from top to bottom. The bauxite with economic significance is mainly concentrated in the clastic layer and the hard crust, while the bottom clay layer prevents the bauxite from moving downward. The ore minerals in bauxite are mainly gibbsite, but also a small amount of boehmite, mainly composed of granite or basic rocks (such as diabase, The feldspar in the greenstone can be divided into granite bauxite and mafic bauxite, represented by Jarrahdale bauxite deposit and Mount Saddleback bauxite deposit, according to the type of bedrock. The mineralization of bauxite is mainly controlled by climate, parent rock, geomorphology, drainage and vegetation. The effect of vegetation not only ensures the permeability of soil weathering and leaching, but also reduces the rate of soil erosion caused by external factors. Under the comprehensive action of various metallogenic factors, the lateritic bauxite was formed after a long time evolution.
【作者單位】： 中國地質大學(北京)地球科學與資源學院;國土資源部成礦作用與資源評價重點實驗室中國地質科學院礦產(chǎn)資源研究所;
【基金】：國家地質大調查資助項目(編號:1212011120325)的成果~~
【分類號】：P618.45
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本文編號：2245845