瑶岗仙裕新多金属白钨矿选矿厂设计实践

从原矿工艺矿物学研究、选矿试验、工艺流程设计、选矿回水利用及尾矿处理等方面,介绍了湖南瑶岗仙裕新多金属矿建设的各个环节.论述了采、选矿废水回用、尾矿处理设计方案的可行性与合理性,实现了采、选矿厂废水的零排放.     

再生高比重钨合金塑性的研究

对再生高比重钨合金塑性的提高作了较为深入地研究。研究表明:向再生合金原料粉末中加入适量的Ni、Fe元素进行成分调节可显著提高再生合金的塑性;对再生合金进行真空热处理可明显提高再生合金塑性,与热处理前相比,再生合金延伸率提高了约43.42%,截面收缩率提高了约33.88%。     

铜资源的短缺与再生利用建议

中国既是铜资源较贫乏国又是最大铜消费国,其铜资源的有限性和紧迫性势必影响国民经济的健康发展,因此必须充分利用国内外一、二次铜资源．在可持续发展和循环经济理念的指导下,大力发展废铜再生产业,由最大铜消费国转变为最大铜资源再生国．     

废塑料在钢铁行业的应用现状及建议

塑料制品在工业及民用中的不断普及,大量废塑料的回收利用已成为一个重要研究课题。冶金行业具有消纳废塑料的设备和技术优势,国内外对此已开展了积极研究。对废塑料在钢铁行业中的应用的相关研究进行了综合分析,从高炉炼铁、焦化、电炉冶炼、直接还原铁生产等几个方面对废塑料的消纳技术状况进行了总结,可为促进废塑料在钢铁行业中的应用提供参考。     

贵州省主要工业区发展现状与循环经济改造

生态工业园区是企业共生层面的循环经济,是落实循环经济的中观基础。要实现工业的可持续发展,需要以工业生态学为基础,对现有工业区进行循环经济改造,以实现物质循环、能量多级利用和废物产生最小化的生态模式。通过大量的调查研究,初步掌握贵州省现有工业区的类型和特点,分析现有主要工业区的发展现状,找出存在的问题,提出循环经济改造的相应对策。     

再谈风机叶片等复合材料固体废物焚烧法处置存在的问题

对复合材料固废回收及综合利用发展产业发展状况进行了介绍,在数据支撑及国家部门有关政策要求的基础上,指出复合材料现有处理技术及存在的问题.在结合国家能源结构战略调整的大背景下,结合相关企业实际经验,得出了有效可行的解决办法.     

Harvesting microalgal biomass using magnesium coagulation-dissolved air flotation

Coagulation with magnesium was found to be more effective for harvesting microalgae Chlorella zofingiensis with dissolved air flotation (DAF) than the use of Fe³⁺, Al³⁺ or chitosan, and the required coagulant dosage was in the order Mg²⁺ < chitosan < Al³⁺ < Fe³⁺. The Mg²⁺ dosage required depended on the growth phases and culture medium characteristics. An early exponential culture required the highest Mg²⁺ dosage (226 mg g⁻¹), while a late stationary culture required the lowest dosage (36 mg g⁻¹). HPO₄²⁻ and CO₃²⁻ in the culture medium competed with the microalgal cells for Mg²⁺ and increased the Mg²⁺ dosage necessary. No Mg²⁺ addition was required to harvest the freshwater microalgae Scenedesmus dimorphus grown in a pond with tap water with a high Mg²⁺ concentration or the marine microalgae Nannochloropsis sp. The critical coagulation pH ranged between 10.8 and 11.8, with a lower pH requirement at a higher Mg²⁺ concentration. Magnesium hydroxide precipitated with the harvested biomass; however, over 99.5% of the precipitated Mg²⁺ was recovered by washing the biomass with 0.1 M HCl. Microalgal harvesting with Mg²⁺ did not introduce extrinsic coagulant; thus, neither the biomass nor the medium was contaminated.     

Interfacial properties of highly oriented coextruded polypropylene tapes for the creation of recyclable all‐polypropylene composites

The creation of highly oriented, coextruded polypropylene (PP) tapes allows the production of novel, wholly thermoplastic, recyclable “all‐polypropylene” (all‐PP) composites, which possess both a large temperature processing window (>30°C) and a high volume fraction of reinforcement phase (highly oriented PP tapes: >90%). This large processing window is achieved by using coextruded, highly drawn PP tapes. To achieve coherent all‐PP composites the interfacial characteristics following consolidation must be understood. This article investigates the interfacial characteristics of these coextruded tapes by using microcomposite models to create interfaces between tapes of varying draw ratios, drawing temperatures, skin/core ratios, and skin layer thicknesses. The tape drawing parameters are seen to control the interfacial properties in subsequent microcomposite models. The failure mode of these specimens, and hence bond strength, varies with consolidation temperature, and a model is proposed describing and explaining this behavior. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 118–129, 2007     

Effects of catalyst acidity and HZSM-5 channel volume on polypropylene cracking

Effects of catalyst acidity and the restricted reaction volume afforded by HZSM-5 on the catalytic cracking of polypropylene are described. Polypropylene cracking by silica—alumina and HZSM-5 catalysts yields olefins as primary volatile products. In addition, HZSM-5 channels restrict carbenium ion rearrangements and facilitate formation of significant amounts of propene and alkyl aromatic volatile products. The higher acidity of sulfated zirconia compared to the other catalysts results in an increase in the frequency of hydride abstractions, resulting in the formation of significant yields of saturated hydrocarbons and organic residue for this catalyst. Primary polypropylene cracking products can be derived from carbenium ion reaction mechanisms. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 341–348, 1998     

Fabrication of the superhydrophobic natural cellulosic paper with different wettability and oil/water separation application

Renewable superhydrophobic materials have attracted great attention due to their extensive applications in the fields such as cost-effective and biodegradable oil/water separation field. Herein, we reported an eco-friendly and facile methodology to develop the superhydrophobic cellulosic paper by immersion method using the ethanol solution of stearic acid. Furthermore, the treated cellulosic papers showed super-hydrophobicity with water contact angle (WCA) above 153°. Interestingly, this method can realize superhydrophobic-hydrophilic conversion by simply adjusting the temperature and is amenable for different substrates and with the WCA of 114-162°. More importantly, the utilization of fluorinated reagents has been avoided, thereby minimizing the production cost and improving safety and environmental aspects. Meanwhile, the modified natural cellulosic paper is applied for oil–water separation, and its separation efficiency was as high as 95% after 10 cycles, indicating the good reusability of stearic acid modified filter papers. Consequently, this simple strategy based on the stearic acid immersion method thus provided an easy conversion of superhydrophobic-hydrophilic interface and provided facile strategies for conversion of commercial quantitative filter paper to functional materials for oil/water separation.