Influence of pretreatment process on structure, morphology and electrochemical properties of Li[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_2 cathode material

The layered Li[Ni1/3Mn1/3Co1/3]O2 was separately synthesized by pretreatment process of ball mill method and solution phase route, using [Ni1/3Co1/3Mn1/3]3O4 and lithium hydroxide as raw materials. The physical and electrochemical behaviors of Li[Ni1/3Mn1/3Co1/3]O2 were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, field emission scanning electron microscopy （FESEM） and electrochemical charge/discharge cycling tests. The results show that the difference in pretreatment process results in the difference in compound Li[Ni1/3Co1/3Mn1/3]O2 structure, morphology and the electrochemical characteristics. The Li[Ni1/3Mn1/3Co1/3]O2 prepared by solution phase route maintains the uniform spherical morphology of the [Ni1/3Co1/3Mn1/3]3O4, and it exhibits a higher capacity retention and better rate capability than that prepared by ball mill method. The initial discharge capacity of this sample reaches 178 mA-h/g and the capacity retention after 50 cycles is 98.7% at a current density of 20 mA/g. Moreover, it delivers high discharge capacity of 135 mA-h/g at a current density of 1 000 mA/g.

Review on biomass metallurgy:Pretreatment technology,metallurgical mechanism and process design

The metallurgy industry consumes a considerable amount of coal and fossil fuels,and its carbon dioxide emissions are increasing every year.Replacing coal with renewable,carbon-neutral biomass for metallurgical production is of great significance in reducing global carbon consumption.This study describes the current state of research in biomass metallurgy in recent years and analyzes the concept and scientific principles of biomass metallurgy.The fundamentals of biomass pretreatment technology and biomass metallurgy technology were discussed,and the industrial application framework of biomass metallurgy was proposed.Furthermore,the economic and social advantages of biomass metallurgy were analyzed to serve as a reference for the advancement of fundamental theory and industrial application of biomass metallurgy.

Recovery and regeneration of LiFePO_(4)from spent lithium-ion batteries via a novel pretreatment process

The recycling of spent LiFePO_(4)batteries has received extensive attention due to its environmental impact and economic benefit.In the pretreatment process of spent LiFePO_(4)batteries,the separation of active materials and current collectors determines the difficulty of the re-covery process and product quality.In this work,a facile and efficient pretreatment process is first proposed.After only freezing the electrode pieces and immersing them in boiling water,LiFePO_(4)materials were peeled from the Al foil.Then,after roasting under an inert atmosphere and sieving,all the cathode and anode active materials were easily and efficiently separated from the Al and Cu foils.The active materials were subjected to acid leaching,and the leaching solution was further used to prepare FePO_(4)and Li_(2)CO_(3).Finally,the battery-grade FePO_(4)and Li_(2)CO_(3)were used to re-synthesize LiFePO_(4)/C via the carbon thermal reduction method.The discharge capacities of re-synthesized LiFePO_(4)/C cathode were 144.2,139.0,133.2,125.5,and 110.5 mA·h·g−1 at rates of 0.1,0.5,1,2,and 5 C,which satisfies the requirement for middle-end LiFePO_(4)batteries.The whole process is environmental and has great potential for industrial-scale recycling of spent lithium-ion batteries.

Process control technology of low NO_x sintering based on coke pretreatment

Process control is an effective approach to reduce the NOx emission from sintering flue gas.The effects of different materials adhered on coke breeze on NOx emission characteristics and sintering performance were studied.Results showed that the coke breeze adhered with the mixture of CaO and Fe2O3 or calcium ferrite significantly lowers the NOx emission concentration and conversion ratio of fuel-N to NOx.Pretreating the coke with the mixture of lime slurry and iron ore fines helped to improve the granulation effect,and optimize the carbon distribution in granules.When the mass ratio of coke breeze,quick lime,water and iron ore fines was 2:1:1:1,the average NOx emission concentration was decreased from 220 mg/m3 to 166 mg/m3,and the conversion ratio of fuel-N was reduced from 54.2%to 40.9%.

Strengthening iron enrichment and dephosphorization of high-phosphorus oolitic hematite using high-temperature pretreatment

The efficient development and utilization of high-phosphorus oolitic hematite is of great strategic significance for the sustainable supply of iron-ore resources in China.In this paper,the mechanism of high-temperature pretreatment for enhancing the effect of iron enrichment and dephosphorization in the magnetization roasting–leaching process was studied by X-ray diffraction(XRD),vibration sample magnetometer(VSM),scanning electron microscopy and energy dispersive spectrometry(SEM–EDS).Compared with the process without high-temperature pretreatment,the iron grade of the magnetic separation concentrate after high-temperature pretreatment had increased by 0.98%,iron recovery rate had increased by 1.33%,and the phosphorus content in the leached residue had decreased by 0.12%.High-temperature pretreatment resulted in the dehydration and decomposition of hydroxyapatite,the dehydration of limonite and the thermal decomposition of siderite,which can produce pores and cracks and weaken the compactness of the ore,improve the magnetization characteristics of roasted ore,and strengthen the iron enrichment and dephosphorization during the magnetization roasting and leaching process.

Pretreatment of super viscous oil wastewater and its application in refinery

Wastewater from super viscous oil processing cannot be effectively treated by conventional wastewater treatment plants in refineries because of its high concentration of various organic pollutants. In order to resolve this problem, a number of investigations were conducted in our work to understand the physicochemical properties, sedimentation, demulsification and pretreatment of such super viscous oil refinery wastewater. The results showed that the key issues for pretreatment of this wastewater were： （1） Optimized process parameters were used in the sedimentation and demulsification processes for oil removal to effectively recover oil and remove scum from wastewater; （2） A suitable flocculation process was selected to minimize oil, suspended solids （SS） and chemical oxygen demand （CODcr）. A pretreatment process including three continuous steps： oil removal by sedimentation, oil removal by demulsification, and flotation separation, was proposed and applied in Liaohe Petrochemical Company, PetroChina and the oil content in effluents was less than 200 mg/L and CODcr less than 2,500 mg/L, which completely met the requirement for influent of the conventional wastewater treatment plant, and the recovered super viscous oil reached 5,873 tons in the initial year in Liaohe Petrochemical Company, PetroChina.

Influence of texture pretreatment on cold rolling texture of ELC-BH sheet

In order to further investigate how cold rolling texture is produced in an extra low-carbon and high strengthbake-hardening sheet steel (for short, hereafter, coiled ELC-BH sheet) with r value as high as 2.67, texture change intexture pretreatment and its effects on the cold rolling texture are researched by means of Orientation Distribution Funchon (ODf) method. Experimental results show that the cold rolling texture which Produces very strong {111 } annealing texture actually is caused by texture change in the texture pretreatment, and the strong {111 } texture obtainedrough this texture pretreatment is an essential condition of engendering the cold rolling texture, while the stability of{111 } texture components in cold rolling is a sufficient condition of emerging thes one.

Composition Characteristics of Gas Hydrate Produced Gas and Pretreatment Research

To accelerate the pace of research and the use of alternative energy strategies Gas Hydrate, on the basis of previous studies, this paper analyzes the composition characteristics of Gas Hydrate produced gas. It provides technical support for our research and the use of Gas Hydrate. This eases the supply and demand of energy and reduces pollution of the atmospheric environment.

预处理工艺对皂荚籽脱壳性能的影响

针对人工剥离皂荚米功效低、成本高,以及现有皂荚籽机械化脱壳装置去壳过程繁琐、脱壳不充分,需循环脱壳且脱壳率低的问题,以分级后安徽省亳州市产皂荚籽为研究对象,提出了一种通过一定浓度的塔塔粉蒸煮皂荚籽后再烘干的预处理工艺。通过自主设计的碾搓式皂荚籽脱壳装置,以脱壳率为评价指标,通过单因素试验和正交试验,分析蒸煮时间、塔塔粉浓度与烘干时间在不同水平下的脱壳效果。试验结果表明:随着塔塔粉浓度的增大,脱壳率先增大后减小;随着蒸煮时间和烘干时间的增加,脱壳率逐渐增大后再逐渐趋于平稳。通过Design-Expert软件分析试验数据,结果显示:对皂荚籽脱壳率影响显著性由小到大的顺序为蒸煮时间、烘干时间、塔塔粉浓度。建立皂荚籽脱壳的回归数学模型并优化求解一组最优参数组合,即蒸煮时间为90 min,塔塔粉浓度为3%,烘干时间为8 h,此条件下脱壳率达到84.42%。

Energy Efficient Manufacturing of Nanocellulose by Chemo- and Bio-Mechanical Processes: A Review

Nanocellulose is a new-age material derived from cellulosic biomass and has large specific surface area, high modulus and highly hydrophilic in nature. It comprises of two structural forms viz., nanofibrillated cellulose (NFC) and nanocrystalline cellulose (NCC). This review provides a critical overview of the recent methods of bio- and chemo-mechanical processes for production of nanocellulose, their energy requirements and their functional properties. More than a dozen of pilot plants/commercial plants are under operation mostly in the developed countries, trying to exploit the potential of nanocellulose as reinforcing agent in paper, films, concrete, rubber, polymer films and so on. The utilization of nanocellulose is restricted mainly due to initial investment involved, high production cost and lack of toxicological information. This review focuses on the current trend and exploration of energy efficient and environment-friendly mechanical methods using pretreatments (both chemical and biological), their feasibility in scaling up and the future scope for expansion of nanocellulose application in diverse fields without impacting the environment. In addition, a nanocellulose quality index is derived to act as a guide for application based screening of nanocellulose production protocols.

Exergetic Efficiencies Evaluation of Flows and Operations on the Mechanical Extraction Process of <i>Jatropha curcas</i>Oil

Jatropha curcas oil is one of the most promising renewable energy sources for rural areas due to its ease of production, which can be used as an alternative to diesel and fuel oil. The development of sustainable energy has been the issue of the discussion about biofuel production given the considerable consumption amount of fossil fuel during the transformation process. And any production process that consumes a lot of energy records a significant destruction of useful energy, which leads to thermodynamic inefficiencies of the process. Besides, the focus on environmental safety is gradually shifting towards energy efficiency in industrial processing. Exergetic analysis is an effective tool for measuring the performance of a production process since exergy is a quantity that measures energy quality. This study assesses the scale of resource degradation in Jatropha oil mechanical extraction processes and finds improving possible pretreatments options for more efficient production. Data from experiments combined with existing databases have permitted to establish the exergy flow balance at each stage of production. The process exergetic yield varies from 29.85% to 35.41% according to the chosen pretreatment process. Mass exergy accounts for 67% of incoming flows and, for outgoing flows, more than 60% is associated with the mass exergy generated by the process waste. The uncertainties analysis on the results was used to validate model results, and to visualize the minimum values for the most unfavorable cases and the maximum values when all the parameters are at their optimum values.

Processing technology of Camellia oleifera seed

Camellia oleifera industry plays a key role in the safety of edible oils in China,and its seed has great potential for comprehensive utilization.This review mainly introduced processing technology of Camellia seed,which included pretreatment,extraction,and high value utilization.The comprehensive utilization and nutritional value of Camellia seed were discussed.Microwave is the best pretreatment method,and shelling technology can improve oil yield.Cold pressing technology was widely accepted and aqueous enzymatic method had wide prospects.Comprehensive utilization technology of Camellia oleifera cake mainly focused on saponin extracting.In the future,processing technology of Camellia seed will be further developed in the direction of improving comprehensive utilization rate to meet new consumption demand.

硅烷化、锆化、硅锆化预处理膜的性能对比

[目的]旨在为碳钢涂装开发性能优良的环保型预处理工艺。[方法]在Q235碳钢表面分别制备了硅烷化、锆化和硅锆化预处理膜,并通过中性盐雾试验、电化学测试、拉拔试验和微观形貌分析,考察了它们的性能。[结果]3种预处理工艺都有效提升了基材的耐蚀性,2 h中性盐雾试验后未处理的碳钢表面腐蚀严重,硅锆化处理的试样表面仅有不超过10%的面积被腐蚀。电化学极化曲线测量的结果显示,预处理后试样的腐蚀电位都正移了,硅锆化试样的腐蚀电流密度只是未处理试样的1/38。电化学阻抗谱测试结果表明预处理后基材的腐蚀反应阻力变大,锆化和硅锆化能令材料的表面粗糙度增大。环氧涂层在3种预处理Q235钢表面的附着力均超过10 MPa,完全符合一般涂装应用的要求。[结论]3种预处理工艺均能有效提升碳钢基体耐蚀性和涂层附着力,其中硅锆化处理的效果最好。

金矿选矿技术研究进展

为助力国内金矿选矿技术攻关,实现金矿资源的高效、合理化开发利用,通过梳理国内金矿资源分布情况及典型黄金矿山的重选法、浮选法、联合工艺和预处理选矿工艺的研究现状,针对性地总结了含碳高砷、高硫、难处理金矿的研究方向,为实现难选金矿资源的高效、合理化开发利用提供了思路。

超声辅助有机酸预处理玉米芯复合酶解工艺优化

为破坏玉米芯木质纤维素的紧密结构以利于酶解、发酵,先通过筛选试验确定最适有机酸及其浓度;再以复合酶解试验确定最佳玉米芯水解酶组成及配比;最后通过响应面试验优化最佳预处理工艺。结果表明,以10%的马来酸对玉米芯预处理后酶水解的最优工艺为料液比25∶1、超声功率310 W,在71℃条件下超声处理34 min,处理后残余物用纤维素酶、β-葡萄糖苷酶和木聚糖酶(1∶2∶1)在pH 4.8、50℃条件下复合酶解48 h。此条件下还原糖得率达34.49%,接近玉米芯中纤维素含量,证明了该预处理酶解工艺稳定、可靠,可为玉米芯发酵生产燃料乙醇提供前期技术支持。

废旧锂离子电池正极材料回收研究进展

随着锂离子电池(lithium-ion batteries,LIBs)在电动汽车、3C电子产品和储能领域的大规模应用和产销量的日益剧增,其退役后带来的金属浪费和环境污染问题也日益突出。有必要大力开发绿色环保、高效低成本的废旧锂离子电池正极材料回收工艺,实现金属资源的周期性利用。回顾了废旧锂离子电池正极材料回收工艺的最新进展。概述了现有的回收工艺,详细介绍了预处理、火法冶金、湿法冶金、生物浸出和直接回收等回收工艺的研究现状。并通过对比分析现有技术存在的问题,综合讨论了各工艺的回收效率、安全性和经济价值。最后,展望了废旧锂离子电池正极材料回收再利用的前景和发展趋势,旨在为直接化、高值化、规模化的废旧锂电池回收再利用研究提供借鉴与参考。

不同预处理对六种药食同源食材加工特性及其饼干品质影响研究

以党参、山药、白扁豆、芡实、麦芽和莲子为原料,探究4种预处理方式(直接粉碎、炒制、蒸制和微波)对6种药食同源混合粉特性、面团特性及饼干品质的影响。结果表明,与对照组(直接粉碎)相比,3种处理对营养成分均有不同程度的破坏,3种处理的混合粉的黏度均提高,持水性与持油性得到改善;3种处理均能改善面团的黏弹性,炒制处理的改善效果最好;炒制处理会降低淀粉的短程有序结构;扫描电镜观察发现淀粉结构均被不同程度破坏,但炒制处理破坏程度最小;3种方式均能减弱食材特有的苦涩味,炒制处理的饼干感官评分最高。综上所述,炒制处理更适合该饼干的加工,制成的饼干有良好的外观以及令大众喜爱的口感。

棉锦弹力罗马布平幅长车前处理生产工艺初探

棉锦弹力罗马布采用传统缸内前处理工艺加工,布面鸡爪痕多、毛羽多、耗时耗能,采用平幅加工则可避免上述问题。针织物平幅长车前处理设备节能高效结合无磷精炼剂TF-1888N对棉锦弹力罗马坯布进行低温平幅长车炼漂处理,白度、毛效、强力等半制品质量符合染色印花需求,且布面折痕小、毛羽少、幅宽稳定、效率高、成本低、产品质量稳定,适宜推广。

高级氧化工艺对饮用水控藻除嗅的研究进展

当前各水源地水华暴发现象频发,导致水源水质污染严重。土臭素(GSM)和2-甲基异莰醇(2-MIB)是较为常见的藻类代谢嗅味产物,也是导致水体产生土臭味的主要原因。常规除藻技术虽然能够去除水体中的藻类,但对其生成的嗅味产物去除效果不佳,因此,亟需新技术在除藻的情况下实现同步去除嗅味产物。文中结合藻类与嗅味产物的相关性,综述常规除藻技术的局限性,介绍高级氧化工艺(AOPs)对于两者去除的研究应用,并认为AOPs将成为同步除藻除嗅技术的研究热点,为同时除藻除嗅技术进一步研究与应用提供理论依据。

超声结合低温清卤两段热加工对鸡肉品质和风味的影响

为探究超声预处理及低温卤煮两段加工对鸡肉品质和风味的影响,本研究以鸡胸肉为研究对象,通过单因素和正交试验研究预煮时间、卤煮时间、预煮温度、卤煮温度对低温清卤鸡肉品质的影响,以剪切力和感官评价为目标值,获得优化鸡胸肉低温清卤的工艺参数。其次,以高温卤煮组(high temperature,HT)和未超声组(without-ultrasonic pretreatment,WUP)为对照,在超声预处理及低温卤煮组(ultrasonic pretreatment and low temperature brine group,UP)的最佳工艺基础上,测定了全质构(texture profile analysis,TPA)、水分含量、颜色、脂质氧化(thiobarbituric acid reactive substances,TBARS)、肌原纤维小片化指数(myofibril fragmentation index,MFI)、蛋白质溶解度和挥发性风味物质水平。结果表明,UP组的最佳工艺为预煮时间10 min,卤煮时间3 h,预煮温度45℃,卤煮温度69℃。与HT组相比,UP组质地参数(硬度,内聚性,弹性,回复性)显著降低(P<0.05),水分含量显著升高(P<0.05),鸡肉颜色属性得以改善,亮度L^(*)值和红度a^(*)值显著升高(P<0.05),脂质氧化水平显著降低(P<0.05)。MFI和蛋白溶解度结果显示超声结合低温卤煮两段加工更大程度地降低了肌原纤维的完整程度,增加了总蛋白的溶解度。感官分析结果表明,低温卤制鸡胸肉虽然气味得分低于高温卤制鸡胸肉,但口感更加鲜嫩可口。气相色谱-质谱法(gas chromatography-mass spectrometry,GC-MS)结果进一步说明超声结合卤煮两段加工能够增加鸡肉挥发性风味物质的种类及含量,但在高温卤煮中鸡肉挥发性醛类物质的含量更多。综上,与其它清卤工艺相比,超声结合低温清卤两段加工提升了鸡肉产品的品质和风味。