基于Buckingham方程的大倍线充填料浆输送优化与应用

大倍线充填料浆管道输送困难及输送浓度偏低等问题是影响矿山充填效益的关键因素,如何低成本实现大倍线高浓度充填料浆的输送,是充填管道输送研究的重要课题。基于宾汉流体(B-H)的Buckingham方程,开展高浓度尾砂浆大倍线自流输送管道优化研究,结合安庆铜矿马头山矿段充填浓度低和输送倍线大的实际情况,采用分段计算、局部优化的方式,以较低的成本实现了安庆铜矿马头山矿段充填管线的优化工作,通过优化改造,输送效果得到明显改善,充填浓度提高了2%,为矿山创造了良好的综合效益。     

我国大变形锚杆研究现状及发展趋势

系统地介绍了我国大变形锚杆的研发现状。通过总结分析现有锚杆设计方案,提出了基于作用机理的大变形锚杆类型划分建议;选取5种典型的设计方案解析了各类型大变形锚杆的优缺点;在此基础上,进一步总结了现有技术方案存在的主要问题,据此对大变形锚杆未来发展趋势提出了几点认识。研究认为:我国大变形锚杆可划分为结构型、材料本质型和其他类型三大类;结构型大变形锚杆包含摩擦型、剪切型和活塞型3个亚类;为进一步促进大变形锚杆的发展,针对结构型锚杆应进一步优化结构、优选锚杆材料、优化制造工艺并保证产品质量稳定性;加大新型杆体材料的开发与应用研究力度;发展具有监测功能的大变形锚杆,将监测技术与大变形锚杆设计相融合,拓展大变形锚杆的应用前景。     

三山岛金矿深井采矿卸压孔卸压数值模拟分析

三山岛金矿深井开采岩爆问题突出,为了保障作业面安全,提出了卸压孔卸压方案,建立了三维数学模型对卸压效果进行了分析,并通过三山岛金矿深部-780 m采场进行了实施。应力测试结果表明,卸压孔可以有效形成一定范围的降压区,降低了岩爆发生几率。     

导爆管雷管起爆网路逐孔起爆设计

提出了逐孔起爆网路各炮孔孔内雷管起爆时间计算公式,并通过计算机编程设计,快捷方便地计算出了在既定延时导爆管雷管组合下各孔的起爆时间,并清楚地显示出点燃阵面;计算出了不同段别导爆管雷管在不同组合情况下的各炮孔孔底起爆时间。据此,可根据实际情况选择合适的延时时间,从而选择合理的雷管组合和联网方式,实现使用导爆管雷管实现不同延时时间的逐孔起爆,为导爆管雷管起爆网路逐孔起爆设计提供参考。     

Mobilization of phosphorus from iron ore by the bacterium Burkholderia caribensis FeGL03

The bacterium Burkholderia caribensis FeGL03, isolated from a Brazilian high-phosphorus iron ore, was used to mobilize the phosphate contained in the same ore. The phosphate-mobilizing ability of the organism was tested in shake-flask cultures containing sterilized crushed iron ore in a chemically-defined liquid culture medium containing glucose (1 g/l) as carbon source and no phosphorus source except the ore itself. Phosphate removal from the ore was determined by measuring the residual phosphate contained in the ore after the bacterial treatment. The time course of the phosphate mobilization process was determined with two different particle sizes (2.0 mm and 0.2 mm mean size) of the crushed ore under conditions of unlimited and limited air exchange. Between 5% and 20% of the phosphorus originally contained in the ore was mobilized in 21 days of treatment. Other variables such as dissolved Fe, pH and cell counts were also monitored throughout the trials. It was also found that this bacterium accumulated gluconic acid in the spent broth. Scanning electron microscopy, revealed biofilms on the ore surface as a result of the production of exopolymeric substances (EPS). Extraction of the EPS from the cultures and its analysis by Fourier transform infrared techniques revealed the presence of molecular functionalities capable of interacting with the ore surface and with the iron dissolved in the medium. It was found that dense biofilms, formed under limited air exchange, resulted in lower phosphate mobilization from the ore than under unlimited air exchange. This was found to be a consequence of a dynamic process of iron and phosphate re-precipitation within the formed biofilms.     

电流密度对钴−碳化铬复合电镀层组织的影响

研究了电流密度对Co–Cr3C2复合电镀层的组织、生长速率和Cr3C2粉末复合量的影响。随着电流密度从5 A/dm2提高至8 A/dm2,镀层表面先变致密后变粗糙;镀层生长速率逐渐增大,但增大幅度逐步趋缓;粉末复合量呈现先增加后减小的趋势。在试验范围内,电流密度为6 A/dm2时,镀层外观质量最好,粉末复合量最高(质量分数为5.1%),组织均匀性较好。     

Tuning biodegradability and biocompatibility of mesoporous silica nanoparticles by doping strontium

Mesoporous silica nanoparticle (MSN), one of the most widely used nanomaterials, is of poor biodegradability in vivo due to its highly stable Si–O–Si structure. Here, the structural stability of Si–O–Si was regulated by doping strontium ion. Sr-doped MSNs (Sr-MSNs) were synthesized by a cetyltrimethylammonium-bromide-mediated template method and their phase, morphology, structure, physicochemical properties, in vitro degradability and cytocompatibility were investigated. Results indicated that Sr²⁺ was successfully incorporated into MSN with the collapse of the ordered mesoporous structure. Sr-doping significantly improved the specific surface area, in vitro degradability and cytocompatibility of MSN in a Sr-content-dependent manner. Particularly, excessive Sr-doping gave rise to generating impure strontium silicate which converted into disordered amorphous silica during degradation and hindered the biodegradable behaviors of MSN. Hence, the synthetic Sr-MSNs with excellent surface nature, biodegradability and biocompatibility were supposed to be applied as potential carriers for the controllable release of drugs and ions in numerous clinical applications.     

Process optimization of neodymium chloride solutions precipitated by magnesium bicarbonate

Rare earths(REs) are of vital importance for the development of new materials and green energy.Magnesium bicarbonate is one of the most recyclable and environmental-friendly precipitant for REs recovery from leaching solutions. Nd_2(CO_3)_3 has difficulties in industrial production. So in this study,the precipitation of neodymium from chloride solution by magnesium bicarbonate are investigated. The effects of feeding method, [HCO_3~-]/[Nd~(3+)] mole ratio, feeding speed and reaction temperature on yield and impurity(magnesia) content are systematically studied. Results show that the impurity(magnesia)content decreases to 0.010 wt% with a yield approaching to 100% obtained under the conditions of[HCO_3~-]/[Nd~(3+)] = 3.00 by parallel flow addition at 50 ℃. The major impurity(magnesia) in rare earth carbonates mainly presents in the form of physical absorption, which can be easily removed by scrubbing. Therefore, it offers a promising green process that uses magnesium bicarbonate to produce neodymium carbonate due to its cycling of carbon dioxide, magnesium salt and waste water.     

虚拟未建模动态补偿驱动的双率自适应控制

工业换热过程是蒸汽与循环水在换热器中进行热交换,使供水温度达到工艺规定的目标范围内的复杂工业过程.由于存在蒸汽压力、回水流量波动以及换热器内管壁结垢的扰动,导致被控对象模型参数发生未知随机的大范围变化,使控制器积分作用失效,造成内环蒸汽流量和外环供水温度波动,相互影响,甚至谐振.针对上述问题,利用工业换热过程运行在工作点附近的特点,用确定性低阶线性模型和虚拟未建模动态来描述被控过程.将自适应信号法与双率控制技术相结合,提出了以蒸汽流量为内环输出、以供水温度为外环输出的双率自适应控制器,并给出了该控制器的稳定性和收敛性分析.本文将工业换热过程机理模型作为被控对象,进行了半实物仿真.结果表明,对于工业换热过程,在模型参数大范围变化时,本文提出的控制方法可以将供水温度控制在工艺要求的目标范围内.     

工艺矿物学在选厂流程优化中的作用

选矿流程产品的工艺矿物学研究可在矿石性质变化、选厂技术改造时为工艺流程的改进提供方向和依据。内蒙某铜铅锌锡多金属矿生产中在锌硫作业中银和铜损失率分别为13.10%和15.64%。为最大限度地提高资源综合利用价值,选择锌硫混合精矿为研究对象,通过赋存状态研究确定了铜、银回收的目的矿物;通过铜、银矿物嵌布关系密切判断出铜、银走向一致,可同步富集。在此基础上,根据黝铜矿、黄铜矿、铜矿物集合体的单体解离度仅为12.84%、33.65%和25.40%,但铜矿物集合体粒度较粗的特点,提出了对铜矿物集合体再磨,获得银铜精矿的技术方案。最终选矿工艺通过提高再磨细度获得了银品位2 699g/t、铜品位为10.02%的高品位银铜精矿,实现了将锌硫混合精矿中原本损失的铜、银加以回收的目的。