内蒙古某铜铅锌多金属矿选矿试验研究

以内蒙古某铜铅锌复杂多金属硫化矿为研究对象,在对该矿石工艺矿物学研究的基础上,进行了大量的探索试验研究。最终采用先磁选除铁—铜铅混合浮选—铜铅分离—铜铅尾矿选锌的工艺流程,以及应用新型高效铜铅捕收剂QF-11、抑制剂CMC等,获得了含铁49.42%、回收率为56.93%的磁精矿,含铜21.12%、回收率75.49%的铜精矿,含铅48.29%、回收率79.23%的铅精矿,含锌46.73%、回收率86.30%的锌精矿,银综合回收率76.60%,实现了对该矿石综合利用的目的。     

A low phase noise and low spur PLL with auto frequency control circuit for L1-band GPS receiver

A low phase noise and low spur phase-locked loop (PLL) for L1-band global positioning system receiver is proposed in this paper. For obtaining low phase noise for PLL, All-PMOS LC-VCO with varactor-smoothing technique and noise-filtering technique is adopted. To reduce the reference spur, a low current-mismatch charge pump is carefully designed. A quasi-closed-loop auto frequency control circuit is used to accelerate the lock process of PLL. The PLL is fabricated in 180 nm CMOS Mixed-Signal process while it operates under 1.8 V supply voltage. The measured output frequency of PLL is 1.571 GHz and output power is −1.418 dBm. The in-band phase noise is −98.1 dBc/Hz @ 100 kHz, while the out-band phase noise is −130.3 dBc/Hz @ 1 MHz. The reference spur is −75.8 dBc at 16.368 MHz offset. When quasi closed-loop AFC is working, the measured lock time is about 10.2 μs.     

Quantifying the effect of local interconnects on on-chip power distribution

Existing methods to analyze and optimize on-chip power distribution networks typically focus only on global power network modeled as a two-dimensional mesh. In practice, current is supplied to switching transistors through a local power network at the lower metal layers. The local power network is connected to a global network through a stack of vias. The effect of these vias and the resistance of the local power network are typically ignored when optimizing a power network and placing decoupling capacitors. By modeling the power distribution network as a three-dimensional mesh, the error due to ignoring via and local interconnect resistances is quantified. It is demonstrated that ignoring the local power network and vias can both underestimate (by up to 45%) or overestimate (by up to 50%) the effective resistance of a power distribution network. The error depends upon multiple parameters such as the width of local and global power lines and via resistance. A design space is also generated to indicate the valid width of local and global power lines where the target resistance is satisfied. It is shown that a wider global network can be used to obtain a narrower local network, providing additional flexibility in the physical design process since routability is an important concern at lower metal layers. At high via resistances, however, this approach causes significant increase in the width of a global power network, indicating the growing significance of local power network and vias.     

基于第一性原理研究Heusler合金Fe2CuGa的结构和性能

采用基于密度泛函理论的第一性原理,系统研究了Heusler合金Fe2CuGa的结构、磁性、弹性性能和电子性质.计算结果表明:立方相的基态结构是铁磁态的Hg2CuTi结构.立方到四方的相变几乎是体积不变的,这是形状记忆合金的特性.奥氏体和马氏体的磁矩分别是4.48和4.56μB/f.u..另外,预测了Fe2CuGa的弹性系数.Fe2CuGa的立方结构在力学上是不稳定的而四方结构是稳定的.根据体模量和剪切模量的比值,发现Fe2CuGa在本质上是可延展的.利用态密度的方法解释了Fe2CuGa马氏体相变的来源.     

高梯度磁选技术的分选特点及其应用领域

从高梯度磁选技术的分选特点出发,着重总结了高梯度磁选技术的主要应用领域及发展情况。大量研究应用实例表明,高梯度磁选技术在金属矿、部分非金属矿的分选及工业废水处理等诸多领域具有极其广阔的应用前景。最后提出了高梯度磁选技术的发展方向。     

杂质元素总量对无取向硅钢显微组织和电磁性能的影响

为了深入研究杂质元素对硅钢成品电磁性能的影响,结合工业化生产的0.25%Si无取向硅钢,探讨了C、S、O、N、Nb、V、Ti杂质元素总量分别为83×10-6和105×10-6时,硅钢成品的夹杂物、显微组织及电磁性能变化。结果表明,杂质元素总量会直接影响夹杂物的种类、形貌、数量和尺寸。随杂质元素总量的升高,在0~0.2μm尺寸范围内,单个的、椭球形的Mn S、CuxS夹杂物数量明显增多,两者分别为1 679×104个/mm3和2 661×104个/mm3。这种细小的夹杂物会不同程度的劣化SRA前后硅钢成品的磁感,然后是SRA前硅钢成品的铁损,对SRA后硅钢成品的铁损则影响不大。随着连退温度的升高,杂质元素总量对SRA前硅钢成品的铁损影响差异逐渐缩小为零。     

辽宁某含金铁矿石综合回收的选矿试验研究

辽宁省本溪市某铁矿在生产过程中发现含有金,原矿含金品位为1.47g/t,含铁品位为18.82%。通过浮选回收金+磁选回收铁的联合工艺流程,获得了比较理想的选矿工艺指标。试验矿石在磨矿细度为-0.075mm占65%的条件下,采用硫酸铜作为金载体矿物的活化剂,丁基黄药和丁铵黑药作为捕收剂,采用一次粗选三次精选二次扫选的浮选工艺流程,试验取得的工艺指标为,金精矿含金品位为50.85g/t,金回收率为75.49%。浮选尾矿进行湿式弱磁场回收磁铁矿,粗精矿再磨至细度为-0.075mm 97%再选得铁精矿,试验取得的工艺指标为,铁精矿含铁品位为65.52%,铁回收率为29.42%。     

热处理工艺对铁基软磁复合材料电磁性能的影响

以磷酸为磷化剂对雾化铁粉进行磷化处理,然后在800 MPa压力下压制成环形生坯,分别在H2、N2和空气气氛下进行热处理,制成软磁复合材料磁芯,研究热处理气氛、热处理温度与时间对磁芯电磁性能的影响。结果表明:铁粉经磷化处理后,表面包覆完整均匀的磷酸盐绝缘层;与H2和N2气氛相比,磁芯压坯在空气气氛下热处理后拥有更高的磁导率和较小的磁损耗;空气气氛下500℃处理30 min是较优的热处理工艺,磁芯最大磁导率达到350,在频率为1 k Hz和饱和磁感1T条件下的磁损耗仅为145 W/kg,进一步延长热处理时间或提高热处理温度,磁导率增加不明显,但电阻率显著降低,导致磁损耗显著增加,软磁性能恶化。     

钙钛矿化合物SrFe_(1-x)Cu_xO_(3-δ)(0≤x≤0.3)的制备及磁性

采用溶胶-凝胶法制备钙钛矿结构化合物Sr Fe1-xCuxO3-δ(0≤x≤0.3)的多晶样品,通过X射线衍射(XRD)结合Rietveld结构精修方法研究该化合物的晶体结构,并使用物性综合测量系统(PPMS)研究其磁性能。精修结果表明掺Cu可使样品发生结构转变,x=0的样品为I4/mmm点群的正方结构,而x=0.1,0.2,0.3的样品均为Pm 3 m点群的立方结构,晶格常数随Cu含量的增加而减小。磁性测量的结果表明Cu含量越高,造成铁磁和反铁磁相互作用的竞争越激烈,形成自旋玻璃态;x=0.1,0.2,0.3的样品转变温度低于x=0的样品,但随Cu含量增加,x=0.1,0.2,0.3的样品转变温度逐渐升高;随Cu含量增加,Fe/Cu位的有效磁矩减小。