植物有效成分间歇浸取动力学研究进展

介绍了植物有效成分间歇浸取动力学模型的理论基础、数学处理方法、发展沿革和研究进展.根据间歇浸取动力学模型特点将浸取动力学模型分为平衡浓度模型和瞬时浓度模型,详细介绍了两种模型的建立.大多数有关植物有效成分浸取动力学研究都是以平衡浓度模型为基础的,由于浸取过程中有效成分会参与反应或发生降解,真实的有效成分浸取平衡浓度很难测定,显然该模型对于易反应有效成分或微波、超声等强化浸取过程有不可克服的缺陷.瞬时浓度模型将广泛应用,但是数学处理难度增大.详细介绍了超声、微波等特殊物理场强化条件下浸取动力学方程建立的理论基础、数学方法和研究进展.     

固定床中PET固相聚合的研究

本文利用固定床反应器对N2保护下的PET固相聚合反应进行研究，在低于粘结点温度下预聚合之后再实施高温聚合，可消除切片粘结，提高反应速率及产品质量，建立了化学反应和扩散过程共同控制下的动力学模型，其计算结果表明从粒子中心到表面，固相聚合表现反应速率和分子量随副产物小分子（乙二醇和水）的浓度减小而增大，并且描述了反应温度、载气中小分子含量和预聚体切片粒径对反应的影响，为优化工艺操作，提高产品质量提供了理论依据。     

绿茶连续逆流浸取动力学研究

对绿茶连续逆流浸取的动力学问题进行了研究，用Ｌ型螺旋式连续逆流浸取器浸取绿茶时，浸取温度和水茶比对沿浸取器长度与浸法浓度之间的相互关系有显著影响。但随浸取温度的升高，影响程度减弱，而浸取时间的影响不显著。获得的线性回归方程对该浸取器的设计很有价值。     

多种粒度组成的闪锌矿在浸取过程中的速率模型

在以前的工作中已研究了硫化锌在氯化物溶液中的溶解动力学,这些研究主要是剖析基本的浸取过程机理。在实际的浸取过程中所遇到的矿物粒度组成往往分布在宽阔粒度范围中,它对整个浸取过程将产生较大影响。本文重点在于研究多种矿粒粒度分布对     

铁阳极电凝聚法处理活性红241染料废水动力学分析

目的探讨铁阳极电凝聚方法处理活性红241模拟废水脱色的动力学过程．方法测定电凝聚反应影响因素改变后染料废水吸光度的变化、应用化学反应动力学理论进行分析．结果铁阳极电凝聚法处理活性红241染料废水的脱色反应符合一级反应动力学过程．结论电流密度、染料质量浓度、染料废水初始pH值及电解质的种类及对一级反应速率常数影响显著，而染料废水温度、电解质浓度对一级反应速率常数的影响不明显；脱色速率常数与染料质量浓度之间的指数关系方程为k=0．00605＋0．0575exp（-0．01234c），R^2=0．9987．     

考虑传质作用时炭粒燃烧反应动力学参数测定方法

为解决传质作用不能忽略时炭粒燃烧反应动力学参数不易精确测定的问题，修改了扩散反应速率计算式和燃烧速率表达式，在此基础上，提出了处理燃烧失重数据的方法，采用此方法，能同时整理出燃烧反应动力学参数和扩散反应速率系数，本方法主要适用于气体温度低于１３００Ｋ的燃烧情况。     

累托石层孔材料在废水处理中的应用研究（Ⅸ）——光辐照处理垃圾渗滤液的催化机理

光辐照Ti／Zr层柱累托石处理垃圾渗滤液的反应过程，其催化动力学方程为：y=0．9282x-0.0867，表观速率常数约为0．9282．其总反应速率由内扩散决定．     

B113-2型高温变换催化剂上反应动力学（Ⅰ）——本征动力学研究

使用活塞流管式积分反应器,采用稳态测定技术,在618～723 K、1.0 MPa压力下,对在国产B113-2型铁铬系高温变换催化剂上变换反应本征动力学数据进行了测试.根据测定得到的数据,对幂函数动力学模型进行了参数估计和检验,得到了高度显著的动力学回归方程.从动力学方程可以得出在高温变换催化剂上变换反应动力学参数基本上与传统铁铬系高温变换催化剂一致,但在该催化剂上CO组分对反应速率的影响程度降低,推测可能是由于该催化剂中Cu组分作用的结果;CO2对变换反应速率的抑制作用较大.因此,为提高变换反应速率,应当设法减小CO2的不利影响;H2组分对反应速率的影响很小,在实际应用过程中,可以忽略.     

庚烷中微生物脂肪酶催化酯化反应动力学的研究

对国产解脂假丝酵母脂肪酶Ｃａｎｄｉｄａ ｌｉｐｏｌｙｔｉｃａｌ ｌｉｐａｓｅ在庚烷中催化丁醇与月桂酸酯化反应的动力学进行了研究。结果发现反应不存在扩散限制,仅为动力学控制,符合米氏方程。虽然存在丁醇抑制现象,但底物浓度对反应速率的影响符合Ｐｉｎｇ－Ｐｏｎｇ反应机理,由此推导了反应动力学模型并由实验数据求得了各模型参数。     

微型流化床中煤焦水蒸气气化反应动力学研究

利用微型流化床反应分析仪研究最小化扩散影响条件下的半焦与水蒸气等温气化反应特性及动力学.在实验温度为750~1 100℃内,缩核模型能很好地描述半焦的气化行为,但低温段(750~950℃)和高温段(950~1 100℃)具有明显不同的反应速率-转化率曲线形状和动力学数据.前者受反应控制,其反应速率在初始反应段有最大值,活化能为172 kJ/mol;后者受反应和扩散共同控制,反应速率在转化率为0.15时达最大值,活化能为82 kJ/mol.实验还考察了水蒸气分压对气化反应的影响,并通过n级速率方程求取水蒸气分压的平均反应级数为0.28.在此基础上,进一步得到低温区和高温区的气化反应速率方程.     

钛铁矿的机械活化及其浸出动力学

对攀枝花钛铁矿的机械活化及其浸出动力学进行了研究。结果表明：活化矿的浸出速率控制步骤随浸出的进行而发生变化，在浸出前期为液膜扩散和表面化学反应混合控制，而在浸出后期则为表面化学反应控制。这说明钛铁矿的机械活化过程是由颗粒外层向内层逐步推进的，存在一个未活化的芯层，而且在活性层中活性由表至里下降。对活化层进行了估算，其厚度约为40nm。     

机械活化法强化液晶显示器中铟浸出的动力

以废液晶显示器(Liquid Crystal Display,LCD)面板为原料,介绍了利用机械活化手段强化LCD面板中铟浸出的方法,研究了机械活化法对浸出铟的影响,以及活化后浸出铟的动力学规律。研究结果表明,机械活化法可有效强化LCD中铟的浸出反应。物料经机械活化后,化学活性提高,反应速度加快,表观活化能和表观反应级数均降低。活化30和60 min后的浸铟表观活化能由未活化时的70.2 k J/mol分别降低至53.3和39.7 k J/mol,表观反应级数由原来的1.21分别降低至0.98和0.89。     

二氧化硫液相浸取低品位软锰矿的动力学

研究了液相中二氧化硫对低品位软锰矿的浸出行为。考察了液相搅拌转速、温度、二氧化硫浓度及pH对锰浸出率的影响,研究了软锰矿粒径及表面元素相对含量随锰浸出率的变化,并对其浸出的动力学模型进行了分析。实验结果表明,搅拌转速为400r/min时可消除外扩散对锰浸出率的影响。锰浸出率随温度、二氧化硫浓度的升高而增大,随pH的增大而减小。当锰浸出率为80%时,软锰矿粒径减小约20%,表面锰含量减小73%,硅元素含量增大18%。动力学研究结果表明,软锰矿的浸出过程为扩散-化学反应混合控制过程,反应的活化能为36.85KJ/mol,二氧化硫浓度、氢离子反应级数分别为1.5595和0.5884。     

Technological conditions and kinetics of leaching copper from complex copper oxide ore

The kinetic behavior of leaching copper from low grade copper oxide ore was investigated. The effects of leaching temperature, H₂SO₄ concentration, particle size of crude ore and agitation rate on the leaching efficiency of copper were also evaluated. And the kinetic equations of the leaching process were obtained. The results show that the leaching process can be described with a reaction model of shrinking core. The reaction can be divided into three stages. The first stage is the dissolution of free copper oxide and copper oxide wrapped by hematite-limonite ore. At this stage, the leaching efficiency is very fast (leaching efficiency is larger than 60%). The second stage is the leaching of diffluent copper oxides, whose apparent activation energy is 43.26 kJ/mol. During this process, the chemical reaction is the control step, and the reaction order of H₂SO₄ is 0.433 84. The third stage is the leaching of copper oxide wrapped by hematite-limonite and silicate ore with apparent activation energy of 16.08 kJ/mol, which belongs to the mixed control.     

Kinetics of the leaching of TiO2 from Ti-bearing blast furnace slag

Ti-bearing blast furnace slag is a valuable secondary resource containing about 24 percent of TiO2. In this paper a process of leaching Ti-bearing blast furnace slag with sulfuric acid to recover TiO2, and the kinetics of that reaction, are described. Under laboratory conditions the rate is controlled by a chemical reaction. The leaching reaction is in accord with a shrinking un-reacted-core model. The apparent reaction order of the leaching reaction was 1.222 and the apparent activation energy was 87.01 kJ/mol. The model fits the observed data well until 90% of the TiO2 has be leached from the particles. The model disagrees with observations during later periods of the reaction because the solution becomes supersaturated with Ti ions, which precipitate as H2TiO4. The assumptions of constant reactant concentration and that there is no effect from the product layer on diffusion, also cause the model to deviate from the actual values.     

从民窿毛钨矿中制取仲钨酸铵的研究

本研究对江西等地所产的民窿毛钨矿用碱法提钨进行了工艺试验,结果表明:原始矿石的化学组成,性质和反应温度,压力及苛性钠浓度等对碱浸过程的钨浸出率有显著影响,应用配方技术及添加白钨矿分解剂能较好地解决民窿毛钨矿中高硅、钙等原料的处理,研究还发现了一种未见资料报道的碱浸提钨新方法,此法可使通常处于平衡状态的反应继续进行,明显地提高浸出过程的金属回收率,其浸出率达99％。     

Leaching kinetics of molybdenum from Ni-Mo ore in sulfuric acid solution with sodium peroxodisulfate as oxidant

The leaching kinetics of molybdenum from Ni-Mo ore in sulfuric acid solution with sodium peroxodisulfate was studied.The effects including leaching temperature, reaction time, particle size, stirring speed, and concentrations of sulfuric acid and sodium peroxodisulfate were investigated. The leaching process of molybdenum from Ni-Mo ore is controlled by the chemical reaction through the solid layer across the unreacted shrinking core. The apparent activation energy of the leaching of molybdenum is calculated to be 41.0 k J/mol and the leaching kinetics equation of molybdenum from Ni-Mo ore is expressed as1-(1-a)1/3=3405.7exp[-41030.0/(RT)]t.     

Study on hydrometallurgical process and kinetics of manganese extraction from low-grade manganese carbonate ores

In order to utilize low-grade manganese ore resources effectively, a hydrometallurgical process was developed for manganese extraction in dilute sulfuric acid medium, and the kinetics of leaching manganese was also investigated. At room temperature, manganese from low-grade manganese carbonate ores was extracted by sulfuric acid leaching without reductants. During the extracting process, single-factor analysis method was used to evaluate the effects of grinding fineness, sulfuric acid concentration, liquid-to-solid ratio, agitation rate and leaching time on the leaching efficiencies of Mn and Fe. The optimal leaching conditions are determined as coarse particles of below 2 mm size (without ball-milling), sulfuric acid concentration of 0.86 mol/L, liquid-to-solid ratio of 5:1, agitation rate of 150 r/min and leaching for 180 min at room temperature. Under the optimal conditions, the leaching efficiencies of Mn and Fe are 96.21% and 13.35%, respectively. In addition, through the experiments at different temperatures, it is found that the leaching process follows the shrinking core model under the conditions of changing acid concentration and intermittent reaction device. Moreover, the apparent activations of effective diffusion and chemical reaction in the kinetic model are calculated to be 18.83 and 27.15 kJ/mol, respectively.     

电镀污泥中铜的浸出工艺及其动力学

以硫酸为浸出剂,对某表面处理工业园电镀废水处理污泥中的铜做了浸出试验研究.将污泥干燥、研磨,X射线衍射和X射线能谱仪分析表明污泥中含铜19.03%.采用单因素优化试验探讨了固液比、反应时间、浸出温度、硫酸质量分数、搅拌速度对铜浸出率的影响.结果表明:当硫酸质量分数为20%,固液比为1∶10,搅拌速率为700r/min时,在20℃下反应40min,铜的浸出率可达97%以上;根据未反应核收缩模型,对硫酸浸铜过程的动力学机理进行了研究,结果表明:硫酸浸铜过程的控制步骤为固体膜扩散控制,其反应级数为0.828 2,浸出活化能为11.809kJ/mol.研究为含铜电镀污泥安全处置提供理论依据.     

Leaching kinetics of low-grade copper ore with high-alkality gangues in ammonia-ammonium sulphate solution

The leaching kinetics of low-grade copper ore with high-alkality gangues was studied in ammonia-ammonium sulphate solution. The main parameters, such as ammonia and ammonium sulphate concentrations, particle size, solid-to-liquid ratio and reaction temperature, were chosen in the experiments. The results show that the increase of temperature, concentrations of ammonia and ammonium sulphate is propitious to the leaching rate of copper ore. The leaching rate increases with the decrease of particle size and solid-to-liquid ratio. The leaching rate is controlled by the diffusion through the ash layer and the activation energy is determined to be 25.54 kJ/mol. A semi-empirical equation was proposed to describe the leaching kinetics.