分流预成型强化制粒改善镜铁矿粉烧结性能

针对镜铁矿精粉成球性及可烧性差的特点,采用分流预成型强化制粒工艺对进口镜铁矿精粉制粒及烧结性能开展研究.与常规制粒工艺烧结指标相比,采用分流造球强化制粒烧结工艺,焦粉配比从4.85%降至4.20%,利用系数从1.44 t·m^-2·h^-1提高至1.71 t·m^-2·h^-1,转鼓强度从57.60%提高至63.80%,固体燃耗从76.46 kg·t^-1降至65.24 kg·t^-1;采用分流辊压预成型强化制粒烧结工艺,焦粉配加量从4.85%降至4.70%,利用系数从1.44 t·m^-2·h^-1提高至1.64 t·m^-2·h^-1,转鼓强度及固体燃耗基本不变.因此,分流预成型强化制粒工艺较常规制粒工艺能显著改善镜铁矿烧结性能.其作用机理为:镜铁精矿经分流预成型后能改善混合料的透气性,降低焦粉配比,提高烧结料层氧位,生成更多的铁酸钙及赤铁矿,所得成品烧结矿结晶完善,矿物之间胶结紧密,内部气孔由不规则大孔变为总体分布较为均匀且大小适中的规则球形,改善了烧结矿的强度和还原性.     

湿法制粒与流化床工艺制备海水仔稚鱼微粒饲料研究

本研究采用湿法制粒、流化床制粒包衣、湿法制粒流化床包衣三种工艺分别制备海水仔稚鱼微粒饲料,并对饲料的性能进行分析比较。固体原料超微粉碎后粒径小于20 μm,然后与液体原料经充分混合后作为基础饲料。制备的饲料粒径大多为150～840 μm。扫描电镜观察结果：湿法制粒工艺制备的饲料表面没有连续均匀一致的表面结构;流化床制粒包衣工艺制备的饲料表面有光滑致密的包衣膜;湿法制粒流化床包衣工艺制备的饲料形状较规则,表面有连续均匀一致的包衣膜。湿法制粒、流化床制粒包衣、湿法制粒流化床包衣三种工艺制备的微粒饲料（250～420 μm）在3.50%NaCl溶液1 h的氮保留率分别为43.6%、52.3%、57.5%;沉降速率分别为5.1、4.5、4.9 mm/s;均能均匀的分散于整个水体。     

海藻酸钠-壳聚糖-五倍子提取物微胶囊琼脂平皿扩散法抗菌性研究

本文采用锐孔造粒法,以海藻酸钠、壳聚糖为壁材,五倍子提取物为芯材制备了海藻酸钠-壳聚糖-五倍子提取物微胶囊。利用扫描电镜、红外光测试等手段确定了制备此微胶囊的最佳工艺,并采用琼脂平皿扩散法测定及评价了所制备微胶囊的抑菌性能。实验结果表明:制得的微胶囊包封效果、成球性和粒径均一性良好,且具有较好的抑菌性能,抑菌效果理想。     

湿法造粒生产炭黑新技术的开发

通过对湿法造粒生产炭黑新技术的研究与开发,用焦炉煤气代替油作为燃料,实现了焦炉煤气综合利用,降低了炭黑生产成本,减轻了环境污染,提高了炭黑产品质量,增加了炭黑品种,经济和社会效益显著。     

基于前馈补偿策略的制粒湿度控制系统设计与实现

介绍了韶关冶炼厂制粒湿度控制系统.构建了一种有前馈补偿的改进型继电反馈控制模型,设计了由电控阀、水分仪、PLC及工控机组成的上、下位机控制系统,基于组态王6.0软件组态实现了制粒湿度的数据采集、自动控制、远程监控和报警等功能.     

上位机组态软件和M340在脱硫石膏造粒系统中的应用

针对电厂脱硫石膏资源现状,结合自动化控制技术,设计了脱硫石膏造粒控制系统.该系统采用施耐德PLC M340系统和上位机组态软件Vijeo Citect,完成对脱硫石膏生产设备加料、蒸汽干燥、疏水、造粒、传递等系统的监控和运行报表管理、事故报警、趋势分析、操作员监控操作等功能.通过现场电气系统的实际运行和调试,验证了控制...     

NiZn铁氧体粉料生产中喷雾造粒用料浆的研究

通过控制料浆中粉料的粒度及料浆固含量,制成喷雾颗粒料。研究了在此条件下制成的喷雾颗粒料特性。结果表明:当粉料的粒度(D50,下同)控制在1.5μm时,颗粒料中聚乙烯醇的质量分数可从0.73%增加到1.33%,从而使喷雾颗粒料的粘结性得到加强;当料浆固含量(质量分数)由64.52%增加到68.97%时,喷雾颗粒料的表观密度由1.30g/cm3提高到1.40g/cm3以上。     

Manufacture of Slow-Release Matrix Granules by Wet Granulation with an Aqueous Dispersion of Quaternary Poly(meth)acrylates in the Fluidized Bed

ABSTRACT

Slow-release matrix granules were manufactured in the fluidized bed using an aqueous dispersion of quaternary poly(meth)acrylates (Eudragit® RS 30 D) as binder for granulation. A factorial design was carried out to investigate the influence of the following parameters, spraying rate, applied polymer amount, and inlet air temperature, on various granule properties. Prerequisites for a slow release of the model drug theophylline are high spraying rate, high amount of polymer, and low inlet air temperature. No considerable decrease of the drug release rate can be achieved without a subsequent curing of the dry granules. A clear correlation exists between the moisture content of the fluidized bed, indicated by the terminal moisture content (TMC), and the mean dissolution time for 80% of the drug (MDT₈₀).     

“Rolling” phenomenon in twin screw granulation with controlled-release excipients

The developed knowledge regarding use of twin screw granulators for continuous wet granulation has been primarily limited to immediate release formulations in the literature. The present study highlights an issue previously unreported for wet granulation with twin screw extruders when using formulations containing controlled-release (CR) excipients. Long (3–10?mm), twisted noodle-like granules can be produced in the presence of these excipients that are difficult to control and are anticipated to create complications in downstream unit operations to the granulator. Working with two different CR excipients, METHOCEL? K4M and Kollidon® SR, each blended at different ratios with a mixture of 80% α-lactose monohydrate/20% microcrystalline cellulose, these unique particles were found to be produced in the conveying elements of the extruder, arising from a rolling action at the top of the screw flights. The CR excipients adhesively strengthen the wetted mass, forming this undesired granule shape such that they persisted to the exit of the machine; the shape appeared most strongly affected by screw speed, producing particles of higher aspect ratio as speed was increased. Adjusting the concentration of these CR excipients in the formulation, the flow rate or the type of compression element used in the screws proved ineffective in controlling the problem. Rather, a re-design of the extruder screws was required to prevent generation of these extended-form granules.     

Air-dictated bottom spray process: impact of fluid dynamics on granule growth and morphology

Background: Growing interest in the use of the less-explored bottom spray technique for fluidized bed granulation provided impetus for this study. Aim: The impact of fluid dynamics (air accelerator insert diameter; partition gap) and wetting (binder spray rate) on granule properties were investigated. Method: In this 3³ full factorial study, the results were fitted to a quadratic model using response surface methodology. The air velocity at the spray granulation zone for the investigated conditions was measured using a pitot tube. Results: Air accelerator insert diameter correlated to measured air velocity at the spray granulation zone and was found to not only dictate growth but also influence granule morphology. The partition gap was found to play important roles in regulating particle movement into the spray granulation zone and optimizing process yields, whereas binder spray rate significantly affected granule morphology but not granule size. Conclusions: Unlike conventional fluidized bed granulation, ease of modulation of fluid dynamics and insensitivity of the bottom spray process to wetting allow flexible control of granule size, shape, and flow. Its good drying ability also indicated potential use in granulating moisture-sensitive materials.