反浮选—冷结晶氯化钾生产过程中硫酸钙旋流分离试验研究

为了有效地分离粗光卤石矿中的硫酸钙颗粒,在实验室筛分分级法的基础上,利用水力旋流法,对青海盐湖钾肥公司提供的试样进行了实验室分离试验及工业试验研究.实验室试验结果表明,通过水力旋流器旋流分离粗光卤石矿的CaSO4,在一定的进料浓度范围内,旋流器均有较好的分离性能,运用二级旋流分离,可以使二级旋流分离下出口物料CaSO4降低至0.3%.粒度分布表明,一次旋流分离大颗粒在上出口物料及小颗粒在下出口物料中夹带量不大,且经过二级分离可以提高分离精度.     

水力旋流器用于一碳汁分离

旋流器是分高两种不同状态物质常用的设备。应用液体的旋流作用来分离液相和固相的旋流设备称为水力旋流器。水力旋流器在其它行业上早已被广泛应用,如淀粉厂,但在制糖工艺生产上,水力旋流器仪在糖浆的固液分离上有所应用,其实它的使用范围远远不止这些。我厂于1998年12月16日在一碳计上试装了一台水力旋流器,利用该设备的分离性能想达到以下目的：（1）为制糖工艺生产提供稳定的泥汁,利用泥汁搞好回流,减少石灰乳用量,提高糖汁的清净效率。（2）通过水力旋流器的作用减少一碳过滤糖汁中的CaCO3含量,减轻（增稠）过滤上的压力,…     

水力旋流器固液分离特性的数值模拟与优化

采用计算流体力学(CFD)软件对水力旋流器内玉米淀粉颗粒的分离效能和分离过程进行数值模拟,对比分析进口流速、分流比和进料浓度变化对旋流器分离效率的影响及其变化规律,考察不同粒径淀粉颗粒在旋流器内的体积分数分布。运用响应面法(RSM)中Box-Behnken试验设计对水力旋流器进行参数优化,分析进口流速、分流比和进料浓度对玉米淀粉分离效率的影响规律,并建立二次多项回归模型。结果表明:进口流速、分流比、进料浓度对玉米淀粉分离效率均有影响,且影响分离效率的大小顺序为:分流比进料浓度进口流速;适当调整进口流速、分流比和进料浓度有利于提高旋流器的分离效率;通过响应面法优化得到的最佳参数条件为:进口流速8m/s、分流比5%、进料浓度12%,该条件下水力旋流器分离效率为98.84%。     

青海冷湖钾盐矿提钾工艺优化研究

通过对青海省冷湖镇北部新盐带钾矿床选矿及加工工艺研究后发现,低品位含砂光卤石矿钾矿床盐田晒卤工艺分为原卤在钠盐池中蒸发—调节池中再蒸发—光卤石池中再蒸发。这种低品位含砂光卤石制取氯化钾工艺主要有冷分解-浮选法和4#工艺法。采用4#工艺和浮选工艺相结合的方法,可以有效的减少盐田矿的析出量,起到降低成本的作用。     

文摘

<正> 需要净化的拉拔乳化液含有粒度大小不同的污染物。单独使用水力旋流器,不能把细颗粒污染物净化到满意的程度。另一方面,如果只使用过滤器,滤纸会很快被粗颗粒所堵塞,滤纸的耗用量特别大。提出了一种把水力旋流器与滚筒带式过滤器相结合的方法,它可以达到最优净化效果,且使用     

基于CFD的淀粉分离旋流器数值模拟

水力旋流器是淀粉分离的关键设备,应用CFD软件中雷诺应力模型描述湍流,并采用简化的多相流模型对旋流器进行数值模拟.得到旋流器流场的速度场、压力场以及淀粉颗粒的体积比分布,通过对所得结果分析,发现模拟结果基本符合旋流器的运行规律,这就为淀粉分离水力旋流器的优化设计和结构改进提供了新的研究方法和手段.     

面筋淀粉分离机与小麦淀粉工艺技术研究

现有的面筋淀粉分离机有MJ面筋机,它采用马丁法工艺;旋流器采用水力旋流工艺;三相卧螺分离机的工艺复杂、能耗大。改进后的面筋机可实现连续化流水作业,减轻人工劳动强度,提高劳动生产力、增强面筋淀粉分离效果,与引进设备相比,工艺简捷,能耗降低,可以实现远程监控。     

旋流器空气柱特性的研究

旋流器因具有剪切洗涤作用而成为食品工业中不可替代的分离设备,但是在使用的过程中水力旋流器存在空气柱,会增大能耗、降低分离效率,这也直接影响了旋流器在食品工业中的发展前景。此次研究通过试验和CFD数值模拟相结合的方法对旋流器空气柱的特性进行研究。结果表明:由两端出口进入的空气在相遇后会形成空气柱,并且从底流口进入的空气速度明显高于从溢流口进入的空气速度;随着底流背压的增大,空气柱直径逐渐变小,直到完全消失。     

淀粉洗涤的基本原理

本文旨在对淀粉洗涤系统的基本原理进行介绍，淀粉洗涤的目的在于从淀粉颗粒中分离不可溶蛋白颗粒并去除淀粉乳中的可溶蛋白，长期以来，水力旋流器被用于这种工艺，对水力旋流器内颗粒和悬浮液的基本操作特征的研究，为旋流器在淀粉洗涤工艺上的应用提供重要的数据。对多级逆流洗涤旋流器系统及其性能特点的理论基础的讨论，为了解整个系统的操作特点提供了条件，对于采用自动控制的情况，多有淀粉洗涤系统与系统外部相连接的４个物     

废硅藻土旋流洗涤回收的探讨

介绍了用旋流分离技术对啤酒过滤后的废硅藻土进行洗涤回收的探索性研究, 包括试验研究和分析方法, 底流分率和进料流量对旋流器洗涤性能的影响, 以及旋流洗涤对硅藻土产品粒度的影响     

除硫后制盐母液浓缩结晶析出光卤石的研究

针对海盐场排出的制盐母液,采用机械冷冻法和氯化钙沉淀法将溶液中的硫酸根降低到10 g/L以下得到除硫母液,在不兑入老卤的情况下将除硫母液进行不同蒸发终止沸点下的浓缩,然后将蒸发浓缩后的清液冷却结晶析出光卤石。根据光卤石中的氯化钾含量计算在不同蒸发终止沸点和相同冷却结晶温度下氯化钾的析出率,从而找到除硫母液的蒸发终止沸点与浓缩清液冷却结晶时氯化钾的析出率关系。     

Investigations of Hydrocyclones for Concentration of Cassava Milk

The manufacture of cassava starch in medium — scale factories requires large volumes of water and produces equivalent volumes of effluent. The use of hydrocyclones to concentrate starch milk and thereby reduce water consumption in the extraction of cassava starch was investigated. Basic performance data with selected hydrocyclone configurations were obtained in the laboratory and the results showed conclusively that high and efficient levels of starch separation are possible with considerable potential for water conservation and effluent reduction in starch factories.     

矿卤滩晒副产物制备硫酸钙晶须的实验室研究

以矿卤滩晒副产物为原料,无水氯化镁为晶型助长剂,十二烷基硫酸钠为分散剂,研究了用水热法制备硫酸钙晶须的工艺影响因素.借助扫描电镜（SEM）和电子显微镜分析了硫酸钙晶须的形貌.用热重分析仪对硫酸钙晶须进行热重分析,并对产品进行了粒度分布测定.     

三元共聚物对纺织厂循环冷却水的阻垢性能

针对纺织厂运转过程中的循环冷却水浓缩导致结垢的问题,以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、烯丙基磺酸钠(SAS)、丙烯酸(AA)为反应单体,过硫酸铵(APS)为引发剂,异丙醇(IPA)为分子量调节剂,通过水溶液自由基聚合法制备了SAS/AA/AMPS三元共聚物,研究共聚物的投加量、钙离子浓度、p H值对碳酸钙和硫酸钙阻垢性能的影响,通过FT-IR、SEM和XRD分别对共聚物基团、晶体晶貌、晶体结构进行表征。结果表明:在投加量为3 mg/L、钙离子浓度为360 mg/L时,对碳酸钙的阻垢率高达99%;投加量为5 mg/L、钙离子浓度为1 100 mg/L、p H值为8时,对硫酸钙的阻垢率也都能达到90%。三元共聚物能使碳酸钙的晶体形状发生改变,硫酸钙晶体的结晶度降低,共聚物适用于低硬度弱碱性水质环境阻垢处理。     

光卤石分解制备氯化钾结晶过程分解液浓度特性研究

研究了不同温度下,低钠光卤石分解过程分解液中氯化镁含量、密度、盐度随时间的变化规律,分析了分解液中氯化镁含量与密度、盐度之间的关系,为低钠光卤石分解制备氯化钾结晶过程自动控制提供了理论基础。     

大蒜植株中蒜氨酸酶的纯化方法研究

以新鲜大蒜植株为原料,采用pH7.0的Na+/K+磷酸缓冲溶液浸提蒜氨酸酶,分别研究了硫酸铵沉淀法、聚乙二醇(PEG8000)沉淀法、超滤条件和SephadexG-75色谱柱对蒜氨酸酶的纯化效果。PEG8000沉淀法得到蒜氨酸酶的纯化倍数为5.42,硫酸铵沉淀法得到蒜氨酸酶的纯化倍数为0.60。最佳沉淀条件为:先加入PEG8000至其浓度达到15%(m/v),离心,上清液中继续加入PEG8000至终浓度为25%(m/v),收集沉淀。截留分子量为30ku的超滤膜,在0.1MPa下循环超滤两次,此时蒜氨酸酶纯化倍数为超滤前的1.20倍。SephadexG-75色谱柱可有效地分离蒜氨酸酶峰和杂蛋白峰。     

Heterogeneous reactions of glyoxal on particulate matter: identification of acetals and sulfate esters

Reactive uptake of glyoxal onto particulate matter has been studied in laboratory experiments in a 2 m3 Teflon reaction chamber. Inorganic seed particles of different composition were utilized, including (NH4)2SO4, (NH4)2SO4/ H2SO4, NaNO3, and simulated sea salt, while the relative humidity and acid concentration were varied. The organic composition of the growing particles was measured in situ with an aerosol mass spectrometer, providing particle mass spectra as a means of product identification. Aerosol physical characteristics were also measured with a differential mobility analyzer and condensation nucleus counter. Regardless of seed composition, particle growth was rapid and continuous over the course of several hours. Identification of several mass fragments greater than the glyoxal monomer suggested that heterogeneous reactionsto form glyoxal adducts of lowvolatility had occurred. Temporal analysis of the mass fragments was consistent with a proposed acid-catalyzed mechanism whereby glyoxal is first hydrated, followed by self-reaction to form cyclic acetal structures. Increased relative humidity slowed the formation of higher order oligomers, also consistent with the proposed mechanism. The relative contribution of various oligomers to the overall organic composition was strongly dependent on the relative humidity and hence the particulate water concentration. A mild acid catalysis was also observed upon increasing the acidity of the seed particles. Specific mass fragments were found that could only arise from sulfate esters and were not present on the non-sulfur-containing seed particles. This first evidence of the formation of organic sulfates in particles is presented together with a proposed mechanism and molecular structure. These results suggest that the formation of these products of glyoxal uptake can contribute significantly to secondary organic aerosol.     

Wet-milling of wheat flour: industrial processes and small-scale test methods

Commercial manufacture of wheat starch and vital wheat gluten involves physical separation of starch granules and gluten particles formed in a neutral aqueous system. The wet-separation of gluten proteins and starch from wheat flour is based on their water insolubility, density, and particle size. Upon wetting, gluten proteins in wheat endosperm aggregate and form particles that are larger in size but less dense than starch granules. Wheat starch and vital gluten are currently produced industrially through wet-milling of wheat flour principally by four processes; the Martin, Alfa-Laval/Raisio, Hydrocyclone, and the High-Pressure Disintegration (HD) processes. The industrial processes differ mainly in the forms of the flour-water mixtures presented to the fractionation equipment (centrifuge, hydrocyclone, or screen) or in the initial separation practice of starch and gluten fractions from flour. However, the processes essentially merge into one as the intermediate starch and gluten-particle streams are purified to give >98% pure starch and ∼80% protein vital gluten. Handling of a second-grade starch stream, flour water-soluble, and fibrous residues may differ at various processing steps. Small-scale tests are available to assess the wet-milling quality of flours to be wet-processed by the Martin, Batter, Alfa-Laval/Raisio, and the HD processes. Yet, there are no laboratory tests reported for the Hydrocyclone process. Given the development of numerous new wheat varieties each year and of high-amylose and waxy wheats, it is important that small-scale wet-milling tests to assess the wet-milling quality and suitability of flour samples for the industrial processes be available.     

Effect of Calcium Salts on the Properties of Proteins from Oil Sardine (Sardinella longiceps) During Frozen Storage

ABSTRACT:  The effect of calcium sulfate and calcium chloride on the enzymatic and structural properties of actomyosin isolated from sardine was investigated. Mince was prepared from sardine and different concentrations of calcium chloride and calcium sulfate were added to the mince and kept in frozen condition at −20 °C. The physico-chemical and functional properties of proteins from mince were analyzed as a function of time. The solubility of proteins decreased during storage. The reduction in solubility was less for samples treated with calcium chloride. However, sardine mince showed better functionality during storage in the presence of calcium compounds. The ATPase enzyme activity of actomyosin increased with increase in concentration of calcium and decreased after reaching the maximum value. ATPase activity of proteins from mince decreased during storage at low temperature. The reduction in ATPase activity did not correlate with the loss of functionality of proteins. SDS-PAGE did not reveal any major changes in the protein profile during storage as well as in the presence of different concentration of calcium compounds. The secondary structural content of actomyosin was not altered in the presence of both calcium chloride and calcium sulfate as evident from circular dichroic measurements.