Diversified Genesis of the Laterite Nickel Deposits: A Comparative Study Based on the Global Scale
详细信息
- 责任者：Fu Wei (Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration ; Guilin University of Technology ; Guilin 541004 ; China) ; Niu Hujie
- 刊名：Acta Geologica Sinica
- 出版年：2013
- 卷期：87(6)
- 关键词：红土型矿床 ; lateritic type deposit ; 镍矿 ; nickel ores
- 页码：p.832-849
- 图表：illus., 2 tables, 50 refs.
- 分类号：1001
- issnNo：ISSN0001-5717
- isbnNo：CN11-1951/P
摘要
The laterite has the biggest reserves among the global nickel deposits.Comparative study reveals that laterite nickel deposits are characterized by diversity and oriented-occurrence in the mineralization and metalogenic mechanism.The Fe oxide type is characteristics of the deep laterite layer as the main petrographic face in the ore-bearing weathering crust , the abundant goethite as the main nickel-bearing mineral and lower Ni ore grade but higher Co accompanied.The Fe oxide type is better developed under tropical climate , stable tectonic background , dunite as the parent rock and locally shear belt occurred.The intense oxidation is the key process determinate the deposit formation.The Ni is adopted by ferrous minerals , or enters the lattice of low-crystalline goethite , which makes the supergene nickel enrichment. The hydrated Mg silicate type is characteristics of the deep saprolite layer as the dominant petrographic face , the serpentine and talc as the main nickel-bearing minerals , and the occurrence of high-grade garnierite ore.This type is limited under the combined conditions of tropical rainforest or monsoon climate , active tectonic background and olive-rich parent rock.The intense leaching , the Ni ion exchange reaction between the residue serpentine and leached fluids and the secondary precipitation of garnierite are essential for nickel mineralization.The clay type is characteristics of the special nontronite layer as the intermediate section between the laterite and saprolite layer , and the nontronite as the main nickel-bearing minerals.This type is restricted under coupling conditions of relative dry tropical climate , stable tectonic background , low terrain , impeded-drainage , and serpentine as parent rock.The inadequate leaching leads to nontronite mineral formation and becomes excellent carrier by the Ni ion exchange reaction.