西藏某多金属矿选厂铜钼混合精矿分离试验

西藏某多金属矿选厂的铜钼混合精矿-0.048 mm含量为85%,铜、钼品位分别为19.06%和0.640%,金、银含量分别为6.98和490.90 g/t,99%以上的铜钼矿物为原生或次生硫化矿物。采用高效易降解药剂对该混合精矿进行铜钼分离选矿试验,结果表明,在磨矿细度为-0.048 mm占90%的情况下,以高效易降解的ZG-2为铜矿物抑制剂、HTL-3为钼捕收剂,采用1粗4精2扫、中矿顺序返回的闭路流程分离试样中的铜钼,最终可获得钼品位为47.68%、钼回收率为81.45%的钼精矿,和铜品位为19.26%、铜回收率为99.94%的铜精矿,金、银主要富集在铜精矿中,实现了该铜钼混合精矿的高效、低毒分离。     

立式焦油氨水分离槽改进探讨

介绍了焦油氨水分离槽的操作参数和注意事项,针对生产操作存在的问题,提出了改进意见,对立式焦油氨水分离槽的改进和推广具有借鉴作用。     

BPADA-ODA非对称聚酰亚胺膜制备及CPD/MCPD分离性能研究

渗透汽化膜技术替代传统精馏工艺分离环戊二烯/甲基环戊二烯碳五馏分同系物。以丙酮为非极性成膜添加剂,水为凝胶介质,采用溶胶-凝胶二步法合成BPADA-ODA非对称聚酰亚胺膜,利用FT-IR表征聚酰胺酸和非对称膜组成,SEM表征膜表面和断面结构形貌,并探讨膜厚、原料液流量等膜工艺参数对分离性能的影响。结果表明:BPADA与ODA化学亚胺化完全,膜表面无孔致密,膜断面为致密皮层和指状多孔支撑层构成,膜厚增加,膜分离因子增大而渗透通量减小,最优膜厚为110μm,原料流量为30 m L·min-1。膜分离性能长期稳定,32 h渗透通量可达236.6 mg·m-2·h-1,CPD分离因子达1.61,原料液可分离提纯96.2%(wt)的甲基环戊二烯。     

Scalable classification of nanoparticles: A proof of principle for process design

Nanoparticles like quantum confined ZnS semiconductor nanocrystals, exhibit unique structure-property relationships. Narrow particle size distributions (PSDs) become one of the most important factors to tailor product performance. Size selective precipitation has already been proven to be an effective post processing strategy for ZnS nanoparticles. It is based on the titration of a poor liquid into a stable dispersion, which leads to the preferred flocculation of larger particles. Afterwards, these flocks must be separated from the continuous phase. While on lab scale the formed flocks can be easily separated by centrifugation from the fine fraction, for larger scale production using continuous processes, new concepts are urgently needed. Herein we developed a filtration process for flock removal that allows the handling of larger quantities. For process design, we first investigated the flock properties in order to know how stable the generated flocks are and how the flock properties can be controlled. Then, we replaced the classical flock separation by centrifugation through separation by surface filtration under the constraint that the underlying separation efficiency was not affected. By the future use of properly controlled, alternating filtration modules, our work opens the door for establishing an urgently needed, scalable post-processing for sub-10 nm nanoparticles.     

Flow visualization and transient behavior analysis of luminescent mini-tufts after a backward-facing step

Luminescent mini-tufts method has been used for surface flow visualization for a long time. One major challenging point of this method is quantitative analysis of transient flows and the dynamic structures. This study is focused on the application of luminescent mini-tufts method in transient flows. A backward-facing step (BFS) is used in this analysis, which is one classic model that consists both flow separation and re-attachment processes. In this study, the instantaneous mini-tufts recognition, image averaging and tuft inclination angle/tuft angle estimation processes are introduced for the analysis of luminescent mini-tufts for the first time on backward-facing step flow (Re_m = 2.0 × 10⁵–7.9 × 10⁵ and Re_h = 1.3 × 10⁴–5.3 × 10⁴). Detailed transient features and characterization process for the backward-facing step model are explained in this study. The combination of optical-oil flow and hot-wire anemometry methods with luminescent mini-tufts are also shown useful to give comprehensive flow field information, including the surface flow behaviors, boundary layer, re-attachment position identification, etc. In addition, the decomposition of the luminescent mini-tufts visualization data is also conducted to give the power spectral density (PSD) and characteristic frequencies for the mini-tufts behaviors under transient fluctuating flow conditions.     

某含铁铅锌尾矿中铁分离试验研究

以某含铁铅锌尾矿为研究对象,通过对铅锌尾矿磁化焙烧时碳粉用量、温度、时间以及磁场强度最佳条件的研究,提出从铅锌尾矿中分离铁元素的合理方案,探讨铅锌尾矿中铁元素二次利用的可能性。试验结果表明,磁化焙烧时最佳碳粉用量为20%、焙烧温度为750℃、焙烧时间为80 min、磁场强度为256 kA/m,在此条件下所得精矿的铁品位为58.44%,回收率为16.98%。     

Shortcut assessment of alternative distillation sequence schemes for process intensification

Finding good process schemes is a difficult task due to its search among multiple alternatives. In literature, several methods are successfully implemented as computer tools, but their use is limited to their developers. There are several useful rules of thumb and heuristics providing useful guidelines, but sometimes these are contradictory. Some authors tried to rank the various alternatives, defining heuristic equations to provide a quantitative parameter to choose among possible solutions. In this paper, mathematical model of distillation columns is simplified, assuming infinite number of stages. The resulting proposed equation has a great similarity to one of the previous heuristic ones. A simple equation not relying on heuristics and easy to use in calculation is provided to evaluate the distillation sequence energy efficiency (DSE) for each alternative. This allows to quantify the advantages derived from process intensification for a given feed composition. The proposed equation is dimensionless, as the Carnot efficiency is used instead of the temperature difference between distillate and bottoms. On the other hand, intermediate results provide also useful information. For instance, the Carnot efficiency of each column indicates when a heat pump or enhanced distillation would be useful. The recovery efficiency for each particular compound allows an easy comparison between alternatives, considering variations on the feed composition. The new equation is verified comparing its results with cases already solved in literature using different methods. The results show that all the methods in literature are able to provide the best sequence, except the heuristics-based ones that are not providing an overall sequence evaluation. The novelty of the proposed DSE method resides in its ease of application, compared to nowadays available methods, and requires only the feed composition and products boiling points.     

Production Rate‐Dependent Key Performance Indicators for a Systematic Design of Biochemical Downstream Processes

Key performance indicators have become a common tool in bioprocess development, as they allow an objective and independent rating and ranking of process alternatives screened. A disadvantage of all key performance indicators developed so far is their strong focus on costs, which makes them neglect the influence of the production rate on the profit of the process. But, since both production costs and production rate have an equally strong impact, both should be considered when decisions have to be made. Therefore, two new key performance indicators are introduced in this work, one for batch and one for continuous processing. They combine product yield, purity performance, variable manufacturing costs, and production rate to one objective. Thereby, misguided trade‐offs between these four individual measures can be replaced by one key performance indicator. This ensures a systematic development of biochemical downstream processes.     

Novel method for separation and screening of lubricant-degrading microorganisms and bacterial biodegradation☆

With the rapid increase of lubricant consumption,oil contamination becomes more serious.Biotreatment is an important method to remove oil contamination with some advantages.In this study,acclimatized oilcontaminated soil and used lubricating oil were sampled to isolate lubricant-degrading strains by several methods.51 isolates were obtained and 24-well plates were employed to assess bacterial potential in highthroughput screening.The method was noted for the prominence of oil–water two-phase system with saving chemicals,shortening cycles and lessening workloads.In order to decrease inaccuracy,subculture and resting cells were inoculated into mineral salt medium with 200 μl oil in well plates for the cultivation at 37 °C for 5and 7 days,and the biodegradation potential was characterized by the changes of oil film and cell density.With appropriate evaluation by shaking flask tests,5 isolates were retained for their potentials with the maximum biodegradation from 1500 to 2200 mg · L~(-1)and identified as Acidovorax citrulli,Pseudomonas balearica,Acinetobacter johnsonii(two isolates with different biodegradation potentials)and Acidovorax avenae using 16 S r RNA sequencing analysis.Also,lipase activity was determined using indicator titration and p-nitrophenyl palmitate(p-NPP)methods.The results indicated that only p-NPP was successful to test lipase activity with the range of 1.93–6.29 U · ml~(-1).Although these five strains could degrade 1000 mg · L~(-1)lubricating oil in158–168 h,there existed distinct difference in enzyme activity,which demonstrates that lipase activity could not be used as the criterion to evaluate microbial biodegradation potential for petroleum hydrocarbons.