高炉渣处理综述及螺旋法水渣处理工艺的应用

介绍了高炉渣处理方法。通过对不同高炉水渣处理系统进行分析对比,指出螺旋法水渣处理工艺的优缺点,分析了本工艺应用的现实可能性,介绍了主要的设备和工艺流程布置方案。     

腐植酸造粒粘合剂的研究

给出了用不同粘合剂制备颗粒状腐植酸的试验结果。研究表明，腐植酸钠作为造粒的粘合剂，具有良好的综合指标。当其加入量为腐植酸含量的４％￣５％时，颗粒状腐植酸制成品抗冲击指数达到８２％以上，磨损指数低于８．８％。     

近红外技术监测流化喷雾制粒水份的研究

流化床喷雾制粒是一种较复杂的生产过程，实现生产过程中物料含水量实时监测，对提高产品质量、实现生产装置自动化意义重大。本文探索利用近红外测试分析技术．实现对流化床喷雾制粒生产过程颗粒含水量的实时监测。根据现代NIR理论和不同含水率颗粒光谱特点，采用双光路4波段8光束反射式近红外测试装置，进行含水率测试实验，实现了颗粒含水量在线监测，实验表明本文方法具有较高的测量精度和抗干扰性，为实现产品颗粒含水量自动测控提供了一种新的方法。     

不同粒度下制造业信息化的参考决策模型

从四个方面总结分析了当前制造业信息化过程中存在的主要不足,为解决这些问题,提出了在实施制造业信息化工程中可供参考的不同粒度下的制造业信息化参考模型,说明了不同粒度模型的应用范围和领域,就企业实施信息化过程的需求,提出了三个有针对性的策略,指出了在不同粒度下信息化参考模型对于企业信息化决策的参考价值,为制造业信息化企业实施信息化工程提供了一般性的参考工具。     

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).     

Structure Model of Granules for Sintering Mixtures

Structure model of granules, boundary value of nucleus and powder, and the relationship between granula- tion efficiency and boundary value were investigated. Granules of sintering mixtures are composed of adhesive powder and nucleus. In the mixtures, particles larger than 1.00 mm act as nucleus and particles smaller than 0.25 mm act as adhesive powder. Particles with size between 0.25--1.00 mm can be adhesive powder as well as nucleus depending on the granulation conditions. When the boundary value is close to 0.25 mm, the granulation efficiency is lower than 50%. When the boundary value is close to 1.00 mm, the granulation efficiency is above 90%. The boundary value is influenced by the iron ore type, granulation moisture, fineness of raw materials and burnt-lime activity. Good adhe- sive capability, suitable moisture content, appropriate particle size distribution and high burnt-lime activity make the boundary value move towards 1.00 mm and improve the granulation efficiency.     

HPMC-based granules for prolonged release of phytostrengtheners in agriculture

One of the main aims in agriculture is to guarantee soil wellness, which is a fundamental requirement to produce high-quality crops with high yields. Focused on this aim, periodical administrations of nutrients or phytostrengtheners are often necessary. The most relevant disadvantages of these administrations are the high dosage number required and the low availability of the substance within the soil. For these reasons, a crucial goal to increase the economic and environmental sustainability of the cultivation process is to reduce the dosage number, which can be obtained increasing the active substance availability in the soil. A granular hydroxypropyl methylcellulose (HPMC) matrix, produced using the wet granulation process, was used to encapsulate a phytostrengthener and to guarantee its controlled release. The granular product was characterized in terms of granules properties and phytostrengtheners leaching within the soil. The results showed good flowability and mechanical properties of the granules as well as the possibility to reduce the product leaching with the phytostrengtheners encapsulation in the HPMC matrices.     

“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.     

Numerical simulation of particulate processes for control and estimation by spectral methods

Results of application of pseudospectral methods, also known as spectral collocation methods, to practical particulate processes including growth, nucleation, aggregation, and breakage are presented. For growth‐dominated processes, a considerable reduction in model dimension can be achieved; for pure aggregation and breakage they form a viable option. To handle problems that include aggregation, breakage, and growth phenomena simultaneously, we introduce a hybrid algorithm combining the advantages of spectral methods and cell average or fixed pivot methods for aggregation and breakage. Results are shown for analytical examples as well as real processes taken from the fields of granulation and crystallization. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2309–2319, 2012