2000～2001年国内塑料助剂技术进展(续二)

３热稳定剂硬脂酸镁合成新工艺广东工业大学化工系开发了一种在水介质中由硬脂酸与新生成的氢氧化镁进行皂化反应合成硬脂酸镁的湿法新工艺。与传统的复分解法工艺相比 ,新工艺反应温度明显下降、反应时间大大缩短、反应物料液 -固比大大下低、滤饼湿质量分数显著减少。该工艺适宜的工艺条件为 :第一次加碱量５０%化学计量比 ,反应物料液 -固比３∶１,反应温度６０℃ ,预反应时间３ｍｉｎ;第二次加碱时间２ｍｉｎ,续反应时间５ｍｉｎ［６５］。直接法合成硬脂酸锌的正交试验设计及最佳工艺条件的确定河北科技大学研究了硬脂酸和氧化锌在催化…     

皂化法合成硬脂酸稀土新工艺

本文介绍一种在水介质中由硬脂酸与新生成的氢氧化稀土进行皂化反应合成硬脂酸稀土的新工艺。通过两阶段反应工艺方式并选择适当的碱分配比例［最佳碱分配比例（质量分数）为：第一阶段８０％，第二阶段２０％］，可有效地消除游离酸的不利影响，制得色泽好、纯度高的硬脂酸稀土产品。其主要质量指标与传统的复分解法产品完全等同。反应的最佳工艺条件为：氯化稀土和烧碱溶液浓度（质量分数）分别为４５％和５０％，反应物料浓度（产物质量分数）为２５％，反应温度６５℃，第一阶段反应时间为１５ｍｉｎ，第二阶段反应加碱时间和续反应时间分别为１５ｍｉｎ和１０ｍｉｎ。此法与传统的复分解法相比，可大大提高生产效率和降低能耗、水耗     

利用正交设计研究水热法合成硬脂酸钙

以硬脂酸和氢氧化钙为原料，采用水热法合成出了色泽好的高质量硬脂酸钙。研究表明，反应速率受氢氧化钙粒径、反应温度、反应物料液固质量比等因素的影响。以过74μm筛氢氧化钙为原料，由正交实验设计分析出了影响硬脂酸钙的主要因素，得到了适宜的工艺条件：反应时间为30 min，反应物料的液固比为6 ：1，反应的压力为0.4 MPa，反应温度为60℃。     

能有效抑制碱集料反应的复合矿物掺合料

研究了在80℃养护条件下，掺加复合矿物掺合料对含沸石化珍珠岩集料砂浆碱一集料反应膨胀的影响。研究发现．混凝土中复合矿物掺合料掺量为25％和40％时，可以有效抑制碱硅酸反应，且40％掺量时抑制作用更强。     

一水合硫酸氢钠催化合成硬脂酸己酯的研究

用一水合硫酸氢钠催化硬脂酸与正己醇的酯化反应合成了硬脂酸己酯。考察了催化剂用量、醇酸摩尔比、反应时间对酯化反应的影响。在典型反应条件下(正己醇与硬脂酸摩尔比=1．5：1，0．6g催化剂/0．2mol硬酯酸，反应时间2．5h)，转化率为99.64％，酯化率为99．55％，产品收率为99．66％。     

合成硬脂酸铅的皂化法新工艺

报导了硬脂酸铅皂化法新工艺。研究了反应温度、反应时间和第一步加碱量对产品质量的影响。结果表明,用皂化法工艺可得到优等品PbSt2,较复分解工艺,反应时间缩短、液－固比降低、滤饼湿含量比减小,一步式工艺得到粉状产品,二步式工艺得到颗粒状产品;最佳工艺条件为：一步式工艺反应温度65℃,反应时间10min;二步式工艺第一步的增碱量比50％,反应温度65℃,反应时间10min。     

锗钨酸催化合成硬脂酸乙酯的研究

以硬脂酸和无水乙醇为原料,锗钨酸为催化剂,催化合成硬脂酸乙酯。考察了原料醇酸比、反应时间、催化剂用量等工艺条件对酯化反应产率的影响,并用正交实验优化出较佳的合成条件：醇酸比为9∶1、催化剂与反应物质量比为1∶100、反应时间6h、在此条件下硬脂酸乙酯产率可达95%以上。     

二步法合成EP01441—310环氧树脂的研究

低分子量液态双酚Ａ型环氧树脂是一种热固性高分子材料，低分子量环氧树脂的生产工艺是通过分二次加碱进行开环反应，回收过量环氧氯丙烷后，再进行二次加碱后进行缩合反应来完成的。传统工艺中存在着产品的低质量，高消耗等缺点。     

焦炭的深层反应

研究了反应温度及碱金属对焦炭深层反应的影响、结果表明,焦炭表面反应程度随反应温度提高而增强,还因加碱而增加。     

柠檬酸硬脂酸季戊四醇三元共聚蜡状物的研制

以柠檬酸、季戊四醇、硬脂酸为原料,采用直接酯化的两步反应合成了柠檬酸硬脂酸季戊四醇酯蜡,并对反应条件进行了优化。固定季戊四醇为0.1 mol的最佳条件为：第一步反应温度为200℃,时间1 h,硬脂酸用量28 g,催化剂为总质量的0.4%;第二步柠檬酸用量为10 g,反应温度150℃,反应时间3 h。最终产物为蜡状物质,酸值为2.2 mgKOH/g,针入度为0.1 mm,滴熔点为70℃。     

Multi-scale analysis of alkali–silica reaction (ASR): Impact of alkali leaching on scale effects affecting expansion tests

Alkali–silica reaction expansions are disturbed by a variety of mechanisms (alkali leaching, ASR-gel permeation through cracks, chemical conditions in pore solution water and its dependence on temperature). An important consequence is the difficulty of using the expansion test on specimens to analyse the behaviour of ASR-damaged structures. The paper focuses on the influence of leaching: alkali transport and consumption are modelled using a multi-scale approach (aggregate and concrete scales). The evaluation of the alkali concentration below which expansion stops is needed to perform relevant analysis in various alkali conditions and this alkali threshold is quantified according to calcium concentration and temperature. The impact of the coupling between alkali transport in aggregate and silica reactivity is also studied. Lastly, the consequences of leaching on ASR-expansion are analysed in two case studies drawn from the literature.     

氨碱厂碱渣充分综合利用新技术的研究

以碱渣和二氧化碳为主要原料,通过煅烧反应、消化反应、氯化铵浸取反应、二氧化碳碳化反应、分解反应等工艺步骤,将钙元素和镁元素从碱渣中分离出来,分别得到纯度为99.9%的高纯度轻质碳酸钙、98.9%的碳酸镁和不溶性中性残渣3个产品。新技术使碱渣得到了充分综合利用、母液循环利用和三废零排放,这无疑是碱渣综合利用技术的新突破。其主要原料成本为零,主要成本就是水、电、燃料、设备折旧、人工工资、少量添加剂等,可预期具有良好的环境效益、社会效益和经济效益。新技术一旦实现工业化,结合蒸氨废液资源利用专利技术,将打破氨碱厂可持续发展桎梏和瓶颈。     

吉兰泰盐湖尾矿生产液体盐中试工艺研究

以吉兰泰南线船采二层盐为原料,用氨碱废液和淡水混配后溶采反应脱除硫酸根并生产纯碱用液体盐。采用中试研究优化工艺条件,在中试最佳工艺条件的基础上,确定了聚丙烯酰胺对二水硫酸钙沉降效果的影响。中试研究结果表明最佳工艺条件为:洗渣工序氨碱废液与淡水的体积比为1∶9、洗渣停留时间为2.5 h、制卤停留时间为3 h,反应罐二级脱硫工序n（硫酸根）∶n（钙离子）为1∶0.75、停留时间为5 min。二次沉降过程中聚丙烯酰胺的添加量为62.5 mg/L时,二水硫酸钙的沉降效果较好,液体盐透光率≥80%。优化工艺条件下可达到企业制碱用液体盐标准,其中钙离子的质量浓度≤2 g/L、硫酸根的质量浓度≤5 g/L、氯化钠的质量浓度≥305 g/L,同时采用该工艺能够实现资源综合利用。     

苛化法制备亚微米纺锤形碳酸钙联产氢氧化钠

为了解决制碱白泥所带来的二次污染问题,在苛化法的基础上改进出一种新工艺。该工艺在制碱过程中不再副产白泥,而是将原料中的钙转化生成高附加值的亚微米纺锤形特种碳酸钙,并联产高含量的液体氢氧化钠。研究了消化与苛化工艺条件对碳酸钙粒径和氢氧化钠含量的影响,采用扫描电镜（SEM）对样品形貌做了表征。结果表明：在柠檬酸钠添加量为1%（质量分数）、消化水温为84 ℃、闷灰时间为40 min、加料时间为20 min的条件下,制备出颗粒短径为180 nm、粒径分布为150~200 nm、长径比为3的亚微米纺锤形碳酸钙,并联产出高含量的液体氢氧化钠。     

Effect of synthesis procedure on carbonation of calcium‐silicate‐hydrate

Carbonation of synthesized calcium‐silicate‐hydrate (C–S–H) is difficult to avoid and can have significant impact on the molecular structure. Considerable carbonation was observed in C–S–H synthesized from the double decomposition of sodium silicate and calcium nitrate solutions but not in C–S–H synthesized from the direct reaction of fumed silica and calcium hydroxide solution. In order to isolate the cause of the greater carbonation in C–S–H synthesized by double decomposition, carbonation was induced in phase‐pure C–S–H by reaction with four different water‐based solutions containing dissolved CO₂ with varying pH and alkali content. Powder X‐ray diffraction, thermogravimetric analysis, and ²⁹Si nuclear magnetic resonance were used to probe the carbonation and the resulting changes in molecular structure. The pH of the solution was seen to strongly influence the degree of carbonation, while the alkali content had much less effect.     

组合氯化氢吸收塔净化技术的应用

分析了聚氯乙烯厂电石法生产PVC原有水洗装置存在的问题与不足。详细阐述了水洗碱洗净化装置的原理及组合塔新技术的特点和改进后的效果。     

稀碱法提取酵母RNA的正交试验研究

采用正交设计试验法对稀碱法提取酵母ＲＮＡ工艺过程中的菌悬液浓度、稀碱浓度、反应时间和沉淀剂用量等因素进行了研究。用方差分析处理实验结果表明，１０％酵母浓度、１．０％碱、２．５％氯化钙和６０分钟反应时间是提取酵毒ＲＮＡ的适宜条件，并将其用于啤酒厂废酵母泥的ＲＮＡ提取试验。     

One‐Part Geopolymers Based on Thermally Treated Red Mud/NaOH Blends

In this study, one‐part “just add water” geopolymer binders are synthesized through the alkali‐thermal activation of the red mud which is relatively rich in both alumina and calcium. Calcination of the red mud with sodium hydroxide pellets at 800°C leads to decomposition of the original silicate and aluminosilicate phases present in the red mud, which promotes the formation of new compounds with hydraulic character, including a partially ordered peralkaline aluminosilicate phase and the calcium‐rich phases C₃A and α‐C₂S. The hydration of the “one‐part geopolymer” leads to the formation of zeolites and a disordered binder gel as the main reaction products, and the consequent development of compressive strengths of up to 10 MPa after 7 d of curing. These results demonstrate that red mud is an effective precursor to produce one‐part geopolymer binders, via thermal and alkali‐activation processes.     

氨碱废液溶采二层盐制备优级液体盐工艺研究

针对内蒙古吉兰泰盐湖补水困难、二层盐硫酸根含量高、氨碱废液排量大后处理困难等技术难题,分别探究了二层盐饱和卤水混配氨碱废液制备液体盐工艺,以及氨碱废液混兑蒸馏水后溶采二层盐制备液体盐工艺。通过在线拉曼实验,测得该反应达到平衡需要1 h以上;探究了机械搅拌速率、化学反应时间、氨碱废液与蒸馏水混配比例等因素对液体盐氯化钠、硫酸根、钙离子含量的影响。结果表明：在硫酸根和钙离子物质的量比为1∶1、25 ℃、300 r/min条件下,氯化钙和硫酸钠的反应过程是二水硫酸钙结晶过程的速率控制步骤;二层盐饱和卤水混配氨碱废液制备液体盐工艺中,在相同条件下,反应120 min后分离可获得优级液体盐;氨碱废液混配蒸馏水后直接溶采二层盐制备液体盐工艺中,氨碱废液与蒸馏水体积混配比例为1∶（5.55~6.36）、25 ℃、300 r/min条件下,反应120 min后分离可获得优级液体盐。     

Alkali-silica reaction, pessimum effects and pozzolanic effect

The pessimum proportion and pessimum size effects for alkali-silica reaction-induced deterioration of concrete (ASR) and the pozzolanic effect of fine siliceous admixtures in concrete have been explained based on the proposed ASR model [T. Ichikawa, M. Miura, Modified model of alkali-silica reaction, Cem. Concr. Res. 37 (2007) 1291-1297.]. The attack of alkali hydroxide to aggregate particles composed of ASR-reactive minerals generates the layer of hydrated mature alkali silicate and the layer of less hydrated immature alkali silicate under the mature layer. The mature alkali silicate preferentially reacts with Ca²⁺ ions to convert to fragmental calcium alkali silicate, because the reaction accompanies a significant volume contraction. The immature alkali silicate gradually reacts with Ca²⁺ ions to cover the surface of the reactive minerals with tight layers of calcium alkali silicate called reaction rims. The reaction rims allow the penetration of alkaline solution but prevents the leakage of viscous alkali silicate generated afterward, so that the alkali silicate is accumulated inside the rims to give an expansive pressure enough for cracking the aggregate and the surrounding concrete. Due to the absorption of Ca²⁺ ions by mature alkali silicate, too much increase of the proportion of reactive aggregate causes the deficiency of Ca²⁺ ions for the formation of reaction rims, so that the ASR expansion decreases after passing the pessimum proportion. Very fine reactive aggregate and admixtures with the grain size less than ~ 50 µm preferentially react with alkali hydroxide to convert to mature alkali silicate without leaving any reactive minerals. Homogeneous mixing of the sufficient amount of very fine siliceous admixtures in concrete therefore inhibits the ASR by absorbing Ca²⁺ ions for the rim formation. The resultant fragmental calcium silicate fills the pores in concrete to increase the strength and the durability of the concrete. The admixtures thus act as pozzolanic materials.