云南普雄风化淋积型铌稀土矿床中铌的赋存状态和富集规律初探

云南省建水县普雄风化壳离子吸附型铌稀土多金属矿床(简称普雄矿床)是在滇东南长岭岗碱性岩风化壳中发现的大型铌稀土(Nb-REE)矿床,以稀土为主,共/伴生Nb_(2)O_(5)资源量5.7万吨。本文利用XRD、TIMA、SEM、EPMA、LA-ICP-MS、ICP-MS等测试方法对采自3个钻孔、2条剖面的风化壳及霞石正长岩样品开展矿物学和地球化学研究,旨在揭示Nb的来源、赋存状态和富集规律。结果表明,风化壳中Nb主要来自霞石正长岩中的Nb-U矿物(贝塔石、铌钙矿、烧绿石等)、榍石和片榍石。在弱风化层和半风化层Nb主要赋存于正长石、含铌矿物以及云母类矿物中,而在全风化层和黏土层则主要赋存于高岭石、伊利石、铁锰(氢)氧化物和云母类矿物中,整个风化壳中可能普遍存在携带着全岩一半以上铌含量的含铌矿物(如残留的贝塔石、次生的铌钽铀矿等)。碱长正长岩风化壳中Nb的含量普遍低于霞石正长岩风化壳。在风化壳纵向上,Nb的平均含量总体从弱风化层的99.2×10^(−6)向上逐渐升高到黏土层的160×10^(−6),但单个钻孔中黏土层相较全风化层顶部有所降低。此外,从山顶到山脊、山脚,相同风化层中Nb含量明显升高。综上表明基岩贡献、风化壳矿物组合以及地形地貌差异共同制约了普雄矿床铌的富集规律。

Strengthening Effects of Niobium on High Strength Rebars

It is well known that the strengthening mechanisms of Nb microalloying on low carbon flat product have been widely studied and recognized since microalloying 75, but the application research and strengthening effects of niobium on middle carbon steel like rebars have been incomplete and under argument due to some factors like limited solubility of Nb（CN） in reheating stage, dominant application of vanadium in rebars, as well as uncertain strengthening effect resulted from high rolling temperature and fast rolling speed in finishing rolling stage. Combining with new version of GB1499.2-2018： Steel for the reinforcement of concrete-Part 2： Hot rolled ribbed bars, it is very necessary to clarify the strengthening effects of niobium on high strength rebars for cost saving. In this paper, some new phenomena have been presented and discussed based on industrial trial results of Nb-bearing HRB400E, HRB500E and HRB600（E）, and then strengthening effects of niobium on high strength rebars were discussed.

铌对桥梁结构钢HPS 70W性能的影响

通过向桥梁结构钢HPS 70W中添加不同含量的铌元素,研究了合金元素铌对桥梁结构钢的力学性能、显微组织和析出相粒子的影响。结果表明,铌对桥梁结构钢HPS 70W低温韧性、强度和塑性有显著的作用。