察哈素选煤厂选煤工艺的设计

通过对原煤性质的分析,说明原煤中矸石可能存在泥化现象,原煤煤泥含量低,煤抗碎强度好;原煤粒度组成受多因素影响变化较大,块煤系统能力设计应适当加大;原煤为易选煤,可采用高密度排矸工艺等简单易行的选煤方法。根据原煤性质及主要选煤方法特征,确定察哈素选煤厂采用重介质选煤工艺。根据设备选型原则,对选煤厂各主要设备进行了选型,并建议一次建成15 Mt/a的生产能力。最后详细分析了察哈素选煤厂主厂房内外工艺布置,说明选煤厂设计具有＂设计合理、技术先进、系统可靠、高效低耗、整体配备、管理方便、效益优先＂的优点。     

郭家湾选煤厂优化设计思路

对郭家湾选煤厂从初步设计到优化设计进行项目背景分析。重点介绍了郭家湾选煤厂优化设计思路。其主要是综合原煤性质、用户对产品的要求、最大产率和最高经济效益等因素为依据进行制定。从简化洗选工艺、降低次生煤泥量、丰富产品结构、设备选型科学合理、优化总图等方面进行了论述。优化设计不仅对洗选工艺环节进行了合理选择,同时对设备选型配置、煤流走向、建构筑物都进行了合理优化。     

Functional properties of soy protein fractions produced using a pilot plant-scale process

Soy proteins fractionated by the modified Nagano process (Nagano method) and a simplified pilot-plant process (CCUR method) were studied for their functional properties, including solubility, viscosity, emulsification, and foaming. The functional properties of the three fractions produced by the Nagano method—glycinin (11S), β-conglycinin (7S), and an intermediate fraction (IM)—were studied under a selected range of pH, ionic strengths, and protein concentrations. The 11S fraction was more soluble than the 7S at pH 2–3, whereas the 7S was more soluble than 11S at pH 5–6. Adding NaCl changed the solubility of both fractions at pH 4–5 compared to a neutral pH. Other functional properties were related to solubility in the 7S and 11S fractions. The CCUR method yielded only two fractions, 11S and 7S, and the functionality of those fractions was tested at a neutral pH. The solubility of the CCUR samples was slightly higher at extreme pH levels compared to 11S and 7S fractions from the Nagano method at a neutral pH. The relationship between solubility and other functional properties was clearer in CCUR samples. These results indicate that the simplified pilot-scale CCUR fractionation process can influence the functional properties of the protein fractions.     

青龙寺选煤厂优化设计

通过青龙寺矿区煤质特征分析、筛分和浮沉实验资料分析以及可选性评定,确定了选煤厂产品结构。选煤厂入洗上限为50mm,入洗下限为0.25mm,经粗煤泥分选和细煤泥干燥的研究,最终确定工艺流程为50～0mm原煤采用无压给料三产品重介旋流器分选;1.5～0.25mm的粗精煤和粗中矸煤分别回收后掺入精煤和中煤;-0.25mm细粒煤采用加压过滤机及压滤机联合脱水,脱水后细煤泥可直接掺入中煤或矸石,也可部分或全部进入干燥系统干燥,干燥后的煤泥掺入中煤。此优化设计工艺系统与原地面工艺系统方案相比优势显著。     

Radiation-induced polymerization of ethylene in a pilot plant. II. Development of wet-wall process

Radiation-induced polymerization of ethylene using tert-butyl alcohol aqueous solution as a medium was carried out in a pilot plant with 10 liter reactor at pressures of 100 to 400 kg/cm², ethylene feed rates of 1.2 to 11.8 kg/hr, medium feed rates of 0 to 100 liter/hr, dose rates of 0.6 × 10⁵ to 1.4 × 10⁵ rad/hr, and at room temperature. The space-time yield and molecular weight of polymer were in the range of 1.2 to 16.7 g/liter hr and 6 × 10³ to 2 × 10⁵, respectively. The space-time yield and molecular weight increased with pressure and mean residence time. The space-time yield was the maximum at an ethylene molar fraction of 0.5. The produced polymer was continuously taken out from the high-pressure system as a slurry. The amount of deposited polymer to the reactor wall was markedly decreased, and five full days continuous operation was successfully performed with the space-time yield of 13.5 g/liter hr.     

Effect of feeding soy products with varying trypsin inhibitor activities on growth of shrimp

Six isonitrogenous, isocaloric diets containing commercially defatted, toasted and lightly toasted soy flours (SF) (diets 1 and 2) and four soy protein concentrates (SPC) (diets 3–6) as replacements for 40% of animal protein were fed to satiation to juvenile shrimp (Penaeus vannamei) for 10 weeks. The SPCs used in diets 3 and 5 were chemically modified products with reduced trypsin inhibitor (TI) content. The chemical modification of SF in diet 2, which resulted in an SPC for diet 3, and of SPC in diet 4 consisted of heating at 70°C for 1 hr with 50 mM Na₂S₂O₅, followed by dialysis to remove salt residues. To keep all diets isocaloric, cornstarch was added to replace the oli-gosaccharides lost during processing to an SPC. The TI contents, in mg TI/g diet, were 0.77, 6.14, 0.64, 1.40, 0.92 and 1.72 for diets 1–6, respectively. Shrimp fed lightly toasted SF had the highest weight gain, which was significantly higher than shrimp fed SPC diets 4, 5 and 6, but not significantly higher than shrimp fed diets 1 and 3. No significant difference was observed in survival rates. Shrimp fed diet 3 (with lowest TI) had the highest body percentages of crude protein, while toasted soy flour diet 1, also with low TI, had the lowest content of this constituent. In general, a high body protein reflects good health of the animal and excellent utilization of the feed. At the replacement levels of soy evaluated, TI content did not affect overall weight gain. Presented at the 1991 AOCS Meeting, May 12–15, 1991, Chicago, IL.     

Development of a pilot process for the production of alfalfa peptide isolate

Enzymatic membrane reactors are widely used to produce protein hydrolysates. During the past few years, leaf extracts have been recognised as a good source of high quality protein. The interest in alfalfa protein concentrate (APC), a hydrophobic protein with excellent functional and nutritional properties, is due to its abundance, to its amino acid composition and to its ribulose 1,5‐biphosphate carboxylase–oxygenase content. In order to use this potential protein source in various fields (food, pharmaceutical and cosmetic industries), a pilot process for APC hydrolysis in a continuous stirred tank membrane reactor (CSTMR) was carried out. At pH 9.5 and 40 °C, the hydrolysis of APC (30.6 g dm^?3) by Delvolase (2.4 g dm^?3) with a residence time of 180 min, gave a conversion of 759 g kg^?1 protein at steady state. Coupling the reactor with an inorganic ultrafiltration membrane (Carbosep M5) with a 10 kDa nominal molecular weight cut‐off (NMWCO), allowed production of a soluble and reproducible peptide permeate with 23 g dm^?3 of hydrolysed protein. Phenolic compounds, responsible for the brown colour of the permeate, were removed at pH 5.0 and room temperature by anion‐exchange chromatography using Amberlite IRA900Cl, with a yield of 920 g kg^?1. After electrodialysis and spray‐drying of the decolorised permeate, an alfalfa peptide isolate (API) was obtained. It was soluble over the full pH range and its amino acid composition was comparable to that of the FAO/WHO standard. It could be used as a protein supplement in human diets and other fields. Copyright © 2003 Society of Chemical Industry     

选煤厂跳汰工艺改造实践

针对选煤厂原有跳汰机技术落后、精煤捞坑跑粗及高灰细泥污染精煤等关键问题,采用SKT高效现代化跳汰机替换原有跳汰机,并用振动弧形筛回收粗煤泥的改造方案;实践证明,改造取得了良好效果。     

Development of a pilot-plant process for the extraction of soy flakes with aqueous isopropyl alcohol

Soy flakes were extracted with aqueous isopropyl alcohol (IPA) at 77 C in a Kennedy countercurrent continuous extractor at a retention time of 71 min. IPA concentration was varied from 85.0 to 90.5% w/w and included the 87.7% IPA-water azeotrope. Solvent to meal ratios were varied from 1.5 to 3.0. The oil-IPA miscella leaving the extractor was chilled and coalesced to yield an oil phase and an IPA phase. The IPA phase was recycled to the extractor without being distilled. Excess IPA was expressed from the defatted flakes, and this also was recycled to the extractor. IPA recovered by distillation in the evaporator-stripper and desolventizer-toaster accounted for less than 10% of the total. Refined deodorized oils from the IPA extraction process compared favorably with their hexane counterpart in color, peroxide value and phosphorous and free fatty acid contents. Desolventized meals from the IPA process compared favorably with their hexane-extracted counterpart in protein, ash and fiber content.     

特大型选煤厂工艺设计探讨

斜沟选煤厂一期工程设计生产能力15.0 Mt/a,入洗的8号煤层原煤具有块煤量大、低灰、低硫等特点;分析对比了国内常用块末煤选煤法以及是否脱泥工艺的优缺点;结合斜沟选煤厂产品结构,确定了一期工程可供选择的工艺流程;提出了大型选煤厂工艺设计应遵循的设计原则。     

通辽选煤厂选煤工艺设计方案的确定

通过对内蒙古通辽选煤厂原设计方案的分析及调整,采用三产品重介质旋流器简化分选工艺,经生产实践的检验,达到了投资费用低、分选效果好、对原煤煤质适应性强的预期目标。选煤工艺方案的确定既要以煤质资料为基础依据,更要保证对原煤煤质变化有较广泛的适应性,尤其是入选外来原煤的选煤厂,同时还要结合厂型、设备性能、投资费用等综合因素,经过技术经济方案的综合比较来确定。     

间苯三酚制备的中试设计及工艺优化

对20t/a间苯三酚的中试装置进行了初步的设计与建设,并在该装置内进行了间苯三酚制备的工艺研究。考察了带水剂种类、用量以及投料方式对反应的影响。结果表明,在反应温度为140℃,氢氧化钾用量为78.4 kg,二氯苯酚用量为32.6 kg,在带水剂为二甲苯,用量为360 kg,采用滴加的加料方式,反应11 h,间苯三酚的收率可达到50.1%。     

多聚异氰酸酯固化剂的研制与制备装置

多聚异氰酸酯固化剂是黑龙江省科技攻关项目。本文简述了该产品的研制过程和相关设备的配置。     

阻聚剂配制系统的气力输送技术开发

将气力输送技术应用于丙烯酸丁酯装置的阻聚剂配制系统,成功解决了传统配制工艺存在的瓶颈,具有安全环保、稳定可靠、自动化程度高等特点。着重从工艺设计角度出发,结合丙烯酸丁酯物料及阻聚剂的物理化学特性,通过理论计算和对实际工况的分析,给出设计的基本参数,指导设备加工和制造,再通过现场测试,找出最优的操作参数。测试结果表明:采用氮气输送颗粒状阻聚剂,可以避免固体破碎后产生的粉尘爆炸危险,并且输送量可达到200 kg/h的低流量输送目的。固气比控制在3.3,不阻塞管线,搅拌转速在35 r/min,固体粒子在溶液中分散度较好,不会沉底,溶解速率快。整个配制过程衔接紧密,操作稳定安全,满足实际生产需求。     

Bench-scale and pilot plant preparation of chemically modified polyester resins

The laboratory preparation procedure of a recently developed unsaturated polyester resin was followed to prepare the resin on a large scale (10- and 200-L pilot plant reactors). The process heating rate, reaction temperature, and agitator tip speed were kept constant on scale-up. The resin was successfully reproduced and its properties were unchanged upon scale-up. The effects of reaction temperature and inert gas flow rate on the polyesterification reaction rate were investigated. It was found that a 10°C increase in temperature or a 50% increase in the gas flow rate results in a 50% increase in the reaction rate.     

选煤厂洗水处理工艺的研究与实践

成庄选煤厂采用简化后的煤泥水处理工艺,将全厂煤泥水集中处理;合理添加絮凝剂,使洗水浓度降至10g/L以下;利用连通器原理,实现洗水自动平衡等措施,实现选煤厂洗水闭路循环。     

中小型选煤厂选煤工艺及设备的改造

宝泰隆焦化有限公司选煤厂采用的选煤工艺为:三产品重介质旋流器主选,煤泥用浮选柱浮选、隔膜压滤机脱水;通过将该厂的改造建设投资、产品质量等与另一选煤厂进行对比,证明了该厂的工艺不仅简单灵活、安全可靠、操作方便,而且选煤效率高、生产成本低,适于中小型选煤厂采用。     

兴县选煤厂工艺流程的选择

为设计高效、节能的选煤工艺,分析了兴县选煤厂8-2号煤层和13号煤层的煤质特征,根据煤质特征优化了选煤厂产品结构;通过对比常用选煤方法,确定了兴县选煤厂选煤工艺。结果表明,2个煤层50~0.5 mm各粒级产率总体分布较为均匀,灰分随着粒级的降低逐渐减小,矸石不易碎。50~1.5 mm低密度物产率和中高密度物产率相近,具有轻重产物密度组成倒置的反常现象,不易分选低灰精煤产品。兴县选煤厂以生产动力煤为主,兼顾炼焦配煤,8-2号煤和13号煤按照质量比2∶1生产十级精煤或优质动力煤,也可以生产一般动力煤。选煤厂最终工艺流程为:50~1.5 mm脱泥有压两产品重介质旋流器主再选,1.5~0.25 mm粗煤泥离心机脱水,0.25 mm细煤泥浓缩压滤回收。     

Development of a solvent extraction process for production of nuclear grade dysprosium oxide from a crude concentrate

A solvent extraction process for the production of nuclear grade Dy₂O₃ for its applications in advance heavy water reactor (AHWR) from a crude concentrate of rare earths containing Y₂O₃ 67%, Dy₂O₃ 22%, etc. has been developed and tested by bench-scale counter-current operations. The challenging task of separating Dy₂O₃ from other rare earths with similar chemical properties has been successfully accomplished by adopting a dual cycle solvent extraction scheme based on an organophosphorus extractant 2-ethylhexylphosphonic acid, mono-2-ethylhexyl ester (EHEHPA). Taking the advantage of the extraction order of rare earths with EHEHPA, in the first cycle heavy rare earths including yttrium fractions are separated in the product strip solution, while dysprosium is concentrated in the raffinate solution along with terbium, gadolinium, etc. In the second cycle dysprosium is purified to the extent of >99.5% with respect to other rare earths from the dysprosium concentrate obtained in the raffinate of the first cycle. Effects of process variables such as aqueous acidity, phase ratio, metal concentration in the aqueous feed, scrubbing and stripping acidity etc on separation of yttrium and other heavy rare earths in the first cycle and upgrading the purity of Dy₂O₃ in the second cycle have been evaluated. Under optimized conditions of process parameters, continuous operations of mixer settler yielded kilogram quantity of nuclear pure Dy₂O₃ which exceeds the specifications required. The recovery was found to be >98%. The overall process also produces two concentrates as by-products namely yttrium (>93%, 1st cycle) and terbium (>54%, 2nd cycle) as source materials for further upgradation of these elements.