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992.
通过单因素试验,得到3种配方快速镍刷镀液电压与沉积速度、电极相对速度与沉积速度关系的回归方程和回归曲线,揭示了其中的规律,对机械零件的刷镀修复具有实践意义。 相似文献
993.
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995.
Tool steel consumption reduction feasibility is considered in tool making by the creation of two-layered materials, obtained by deposit welding, which allow for reliability, durability and considerable increase in the high-loaded components and machinery. 相似文献
996.
通过试验分析,得出了温度、pH、浓度与化学镍、化学金析出速率的关系,为精确控制化学镍、化学金的镀层厚度、降低化金成本提供了依据。 相似文献
997.
In mineral exploration, the apparent resistivity and apparent frequency (or apparent polarizability) parameters of induced polarization method are commonly utilized to describe the induced polarization anomaly. When the target geology structure is significantly complicated, these parameters would fail to reflect the nature of the anomaly source, and wrong conclusions may be obtained. A wavelet approach and a metal factor method were used to comprehensively interpret the induced polarization anomaly of complex geologic bodies in the Adi Bladia mine. Db5 wavelet basis was used to conduct two-scale decomposition and reconstruction, which effectively suppress the noise interference of greenschist facies regional metamorphism and magma intrusion, making energy concentrated and boundary problem unobservable. On the basis of that, the ore-induced anomaly was effectively extracted by the metal factor method. 相似文献
998.
《国际露天开采、回填与环境杂志》2013,27(6):407-424
Criteria or transition indicators to guide the complex decision problem of open pit to underground (OP-UG) transition are currently not well defined and documented as most mines rely on context-dependent experiences of their respective project feasibility teams. This problem is further compounded by the fact that transition indicators such as net present value (NPV), stripping ratio and commodity price are dynamic over time. Therefore, traditional deterministic approaches to solving the OP-UG transition problem cannot fully address the practicalities that mining companies face due to the variability of the transition indicators. This paper therefore reviews the OP-UG transition decision problem from a stochastic perspective. Transition indicators identified from an extensive literature review were used to benchmark four case study mines against one which had recently made the OP-UG transition, subsequently leading to the development of a generic OP-UG transition model for gold mines. The model indicates that depending on the type of deposit, gold mines can prepare to transition when the gold price to cost per ounce ratio is just greater than 2.0; grade is between 4 and 9?g/t, stripping ratio is between 3 and 15?m3/t and NPV is positive for the underground mining option. 相似文献
999.
Fungal pretreatment of sulfides in refractory gold ores 总被引:1,自引:0,他引:1
This study assessed the capability of the fungus, Phanerochaete chrysosporium, to decompose pyrite, arsenopyrite and a sulfide-containing flotation concentrate in an effort to develop a microbial process for pretreating refractory gold ores. The extent of biotransformation was monitored by analyzing for iron, sulfur and arsenic in incubation solutions, and for sulfide sulfur in the residual solids. The results were then expressed as percentages of the initial weights. For arsenopyrite, 1.5 wt.%, 7.2 wt.% and 10.3 wt.% of iron, arsenic and sulfur respectively were present as soluble constituents in the incubation solution within 21 days of fungal treatment, whereas for pyrite, there was 1.2 wt.% iron and 6.0 wt.% sulfur. For the same processing period in the case of the flotation concentrate, 1.8 wt.%, 6.1 wt.% and 10.7 wt.% respectively of iron, arsenic and sulfur remained in solution. Overall, the decomposition of sulfide sulfur in the samples was 15 wt.%, 35 wt.% and 57 wt.% respectively for pyrite, arsenopyrite and the flotation concentrate. Changes in sulfide sulfur concentration and the formation of oxide phases during fungal treatment were confirmed using Raman spectroscopy and X-ray diffraction analysis. These results suggest that P. chrysosporium is a potential microorganism for oxidative decomposition of metal sulfides associated with refractory gold ores. 相似文献