谈谈如何提高Na2So4的产品质量

本文介绍了我矿在冷冻提硝工艺中,运用工序管理,严格工序控制以提高Na_2SO_4产品质量的一些作法。     

Na2SO4-H2O2-NaCl加合物工业化生产技术探讨

根据Na2SO4 - H2O2 - NaCl加合物生产工艺和控制要求,结合生产实践,从工艺路线、设备选型、工艺控制等方面进行了探讨.提出了Na2SO4 - H2O2 - NaCl加合物工业化生产技术优化方案.     

选区激光熔化316L不锈钢残余应力优化研究

利用人工神经网络的高度非线性函数逼近能力和自适应学习能力,建立选区激光熔化316L不锈钢成形残余应力预测模型。采用响应面法进行试验设计得到不同的工艺参数组合作为训练样本,通过残差分析验证样本数据的有效性,结合遗传算法对BP神经网络模型进行优化。结果表明,GA-BP神经网络模型的预测值与实际值的整体预测平均相对误差在5%左右,证明通过神经网络模型实现选区激光熔化316L不锈钢成形残余应力预测是可行的。     

Na2S04-H2O2-NaCl加合物工业化生产技术探讨

根据Na2s04-H2O2-NaGl加合物生产工艺和控制要求,结合生产实践,从工艺路线、设备选型、工艺控制等方面进行了探讨。提出了Na2SO4-H202-NaCl加合物工业化生产技术优化方案。     

卤水Na+/Mg2+,Cl-/SO2-4比值对极端嗜盐绿色杜氏藻生长的影响

极端嗜盐绿色杜氏藻是世界上迄今发现的最耐盐的真核光合生物,藻体内含有植物蛋白、脂肪酸、多糖、叶绿素、甘油等多种营养成分和生物活性物质,具有开发天然保健品或生物药品的应用前景、文章依据人工海水理论和方法,研究了水体Na+/Mg2+、Cl-/SO2-4比值对极端嗜盐绿色杜氏藻生长的影响,从而探讨适合该藻类生长的化学环境.     

木素在Na2SO3处理及H2O2漂白中的发色行为

通过定量研究磨木木素色团在Na2SO3处理及H2o2漂白中的发色效果,揭示木素在CTMP化学预处理及漂白过程中的发色行为.研究发现,邻醌和邻酚金属螯合物是Na2SO3处理及H2O2漂白木素的主要颜色来源,共轭羰基对木素颜色不构成主要影响;限制金属离子的引入,可有效地提高CTMP浆的漂白性能.     

木素在Na2SO3处理及H2O2漂白中的发色行为

通过定量研究磨木木素色团在Na2SO3处理及H2O2漂白中的发色效果,揭示木素在CTMP化学预处理及漂白过程中的发色行为。研究发现,邻醌和邻酚金属螯合物是Na2SO3处理及H2O2漂白木素的主要颜色来源。共轭羰基对木素颜色不构成主要影响;限制金属离子的引入,可有效地提高CTMP浆的漂白性能。     

磁性催化剂Na2O·SiO2/Fe3O4的制备及其催化酯交换反应

以Na2SiO3为活性物质,以纳米Fe3O4为磁核制备磁性固体碱催化剂Na2O·SiO2/Fe3O4,通过正交实验,得到催化剂的最佳制备条件为：硅与铁的摩尔比2.5,晶化时间2h,煅烧温度350℃,煅烧时间2.5h,并通过震动样品磁强计（VSM）对催化剂的磁性进行表征。结果表明,所制备的催化剂Na2O·SiO2/Fe3O4具有较好的磁性和顺磁性,抗水性能优于传统均相碱催化剂;将其应用于棉籽油酯交换反应制备脂肪酸甲酯的最优工艺参数为：醇油摩尔比7：1,催化剂加入量5%,反应温度65℃,反应时间1h,搅拌速度400r/min,在此条件下,催化棉籽油酯交换反应转化率为99.6%,连续使用11次后活性仍在90%以上。     

UV/Na_2S_2O_4体系中棉织物上活性染料的浸轧剥色研究

采用紫外光引发和催化还原剂分解的方法,首次对UV/Na2S2O4体系中棉织物上活性染料的低温浸轧剥色进行了研究。以单因素实验法探讨了工作液p H值、还原剂保险粉用量、织物上轧余率和剥色时间等对棉上活性染料的剥色率及织物强力保留率的影响,同时对剥色前后棉纤维的表面形态特征采用扫描电镜进行了观察分析。实验结果显示,染色棉织物经浸轧含有还原剂保险粉的剥色工作液后,在紫外光(UV)的引发和催化下可有效实现对织物上固着活性染料的低温剥色处理。     

316L不锈钢弯头开裂失效分析

脉冲吹灰器的316L不锈钢直吹管弯头使用过程中出现开裂,且开裂发生在弯头弧度最大的地方,开裂处未见明显塑性变形,开裂弯头的内部管壁上有大量的锈垢。采用化学成分分析、金相检验、断口形貌扫描等方法,对开裂原因进行分析。其化学成分符合GB/T 20878—2007要求;金相组织为奥氏体+δ铁素体;断口形貌呈泥状花样。结果表明:应力腐蚀是引起316L不锈钢弯头开裂的主要原因,腐蚀介质为燃烧气体中的氯离子和硫离子,而高温和弯头所受的拉应力也是导致弯头应力腐蚀开裂的原因。     

Induction of pitting corrosion on stainless steel (grades 304 and 316) used in dairy industry by biofilms of common sporeformers

This study hypothesised that there may be induction of pitting corrosion or microbially‐induced corrosion on stainless steel (SS) dairy‐processing surfaces by biofilms of common milk sporeformers such as Bacillus sporothermodurans and Geobacillus stearothermophilus. Scanning electron microscopy (SEM) and micrographs generated from energy‐dispersive spectroscopy were used to observe pitting corrosion and to find the elemental composition and distribution on the control and pitted surfaces. From SEM images and energy‐dispersive spectroscopy micrographs, it was observed that pitting corrosion on SS could be induced by biofilms of both B. sporothermodurans and G. stearothermophilus.     

0Cr17Ni4Cu4Nb不锈钢丝冷拉工艺探讨

对Φ10.70mm0Cr17Ni4Cu4Nb(SUS630)马氏体沉淀硬化型不锈钢丝冷变形过程中易出现拉拔断裂、拉拔后自裂以及冷变形困难进行工艺分析和探讨,指出钢丝表面状态不佳是影响拉拔的主要原因。通过细晶表面处理技术,拉拔时选择道次压缩率8%～12%,使钢丝表面处于压应力状态;盘条热处理采用(1040±10)℃保温1h加上(630±10)℃保温4h时效,中间去应力退火采用(640±10)℃保温2～4h,成品前去应力退火采用(630±10)℃保温4h时效,生产出的Φ10.70mm直条钢丝平均抗拉强度1030MPa,延伸率16.4%,硬度HRC值为31,满足GB/T1220—2007要求,用户使用反映良好。     

高锰低镍不锈钢在含氯介质中重金属迁移行为研究

为科学评价高锰低镍不锈钢在高盐环境下使用的安全性能。以Fe、Cr、Ni和Mn的迁移量为表征指标,研究高锰不锈钢在含氯醋酸介质中的重金属迁移行为。结果表明:高锰不锈钢在含氯醋酸中的重金属迁移量远大于其在不含氯的醋酸介质中的迁移量,且其重金属离子在含氯醋酸中持续迁移析出。     

Experimental investigation of the rising behavior of CO2 droplets in seawater under hydrate-forming conditions

In a laboratory-based test series, seven experiments along a simulated Pacific hydrotherm at 152 degrees W, 40 degrees N were carried out to measure the rise velocities of liquefied CO2 droplets under (clathrate) hydrate forming conditions. The impact of a hydrate skin on the rising behavior was investigated by comparing the results with those from outside the field of hydrate stability at matching buoyancy. A thermostatted high-pressure tank was used to establish conditions along the natural oceanic hydrotherm. Under P-/T-conditions allowing hydrate formation, the majority of the droplets quickly developed a skin of CO2 hydrate upon contact with seawater. Rise rates of these droplets support the parametrization by Chen et al. (Tellus 2003, 55B, 723-730), which is based on empirical equations developed to match momentum of hydrate covered, deformed droplets. Our data do not support other parametrizations recently suggested in the literature. In the experiments from 5.7 MPa, 4.8 oC to 11.9 MPa, 2.8 degrees C positive and negative deviations from predicted rise rates occurred, which we propose were caused by lacking hydrate formation and reflect intact droplet surface mobility and droplet shape oscillations, respectively. This interpretation is supported by rise rates measured at P-/T-conditions outside the hydrate stability field atthe same liquid CO2-seawater density difference (delta rho) matching the rise rates of the deviating data within the stability field. The results also show that droplets without a hydrate skin ascend up to 50% faster than equally buoyant droplets with a hydrate skin. This feature has a significant impact on the vertical pattern of dissolution of liquid CO2 released into the ocean. The experiments and data presented considerably reduce the uncertainty of the parametrization of CO2 droplet rise velocity, which in the past emerged partly from their scarcity and contradictions in constraints of earlier experiments.     

Strong copper-binding behavior of terrestrial humic substances in seawater

In coastal areas, strong complexation of copper generally reduces its toxicity; our ability to monitor and regulate copper as a toxin therefore depends on our understanding of the sources and sinks of the copper-binding ligands. Terrestrial humic substances (HS) are well-recognized contributors to weak ligand concentrations in aquatic systems. In this work, we show that HS are likely contributors to both stronger and weaker ligand classes controlling copper speciation in coastal areas receiving typical inputs of terrestrial organic matter. We used competitive ligand exchange adsorptive cathodic stripping voltammetry (CLE-ACSV), with the added ligands benzoylacetone and salicylaldoxime, to examine copper binding by terrestrial HS in a seawater matrix, at HS and copper concentrations typical of coastal waters. Copper titration data of 1 mg/L Suwannee River humic acid (SRHA) in seawater could be modeled using conditional stability constants of 10(12.0) and 10(10.0) and total ligand concentrations of 10.4 and 199 nM for a stronger and weaker ligand, respectively. Similar results were obtained for Suwannee River fulvic acid (SRFA). Strong copper binding by SRFA in seawater was weaker than previously reported for a freshwater at similar pH, possibly indicating effects of Ca and Mg competition or ionic strength. Nevertheless,the concentrations and binding strengths of copper ligands we observed are comparable to the range reported in previous coastal speciation studies. In addition, we show that the weaker copper ligands cause internal calibration techniques to significantly underestimate the sensitivity of ACSV in the presence of HS concentrations typical of coastal waters. To address this issue, we demonstrate the use of "overload titrations", using a high enough concentration of added ligand to outcompete all natural ligands as an alternative calibration technique for analysis of coastal samples.     

不锈钢餐具中镍含量的测定

研究了以非离子型微乳液乳化剂-OP/n-C4H9OH/n-C7H16/H2O为介质,Ni(Ⅱ)与1-(2-吡啶偶氮)-2-萘酚(PAN)的显色反应,在pH值8.58～10.70范围内,配合物的最大吸收波长为570nm,回归方程:A=0.0313c-0.0066(c/μg·25mL-1),相关系数r=0.9996,表观摩尔吸光系数为4.56×104L/mol·cm,Ni(Ⅱ)浓度在0.2μg/25mL～25μg/25mL范围内服从比尔定律,检出限0.2μg/25mL,相对标准偏差(RSD%)在0.014%～0.64%之间,加标回收率在95.00%～110.9%之间。该法用于合成样和不锈钢餐具浸泡液中镍的测定,结果令人满意。     

我国抗菌不锈钢市场前景广阔

中国的不锈钢消费量已经是全球第一，国内外的大量资本涌入该行业以抢占中国市场。该行业的特点是资本密集和规模效益。显然．作为中国最大的不锈钢企业，担负着整个国内不锈钢行业的重担，所以我们在一直不断的在填补我国不锈钢行业的空白。在2005年，太钢目前己成功研制生产出铁素体抗菌不锈钢（TKJF系列）和奥氏体抗菌不锈钢（TKJA系列）。而世界上只有日本拥有类似的加工技术，太钢由此填补了国内抗菌不锈钢材料的空白。     

不锈钢粉碎磨辊在加工盐中的应用

1　前言目前国内生产食用盐普遍采用两种生产方法 ,其一是真空蒸发结晶工艺 ,其二是利用原盐进行粉碎、洗涤、干燥的生产工艺 ,简称粉洗干工艺。在粉洗干生产工艺中粉碎机是关键设备 ,目前粉碎机使用最多和效果最好的是对辊式粉碎机、其优点是两粉碎磨辊间隙可以调节 ,使得粉碎盐粒度可以调节 ,能够适应市场对多品种的要求。粉碎磨辊拆卸方便 ,并可以经过多次拉丝反复使用 ,确保生产的经济性。2　不锈钢粉碎磨辊的开发研制对辊式粉碎机粉碎磨辊绝大多数采用双层复合式离心铸造 ,内层为灰口铸铁或球墨铸铁 ,外层为硬质合金铸铁 ,主要成分是镍…     

SO2-4/MoO3-TiO2催化合成对羟基苯甲酸丁酯

在固体酸SO2-4/MoO3-TiO2的催化下,对羟基苯甲酸与丁醇直接酯化,再经过滤、减压蒸馏制得合格的对羟基苯甲酸二丁酯,其最佳工艺条件为催化剂用量为反应物总质量的1.0%,n(丁醇)n(对羟基苯甲酸)=2.91.0,反应温度150℃,反应时间2.5h,对羟基苯甲酸的转化率为97.2%,催化剂可重复使用.