Modeling flotation separation in a semi-batch process

A model for a semi-batch flotation separation process has been developed, based on available microprocess probabilities, and compared to experimental data obtained using a WEMCO laboratory flotation cell. In general, the model predicts the correct experimental trends. In many cases, the model also predicts removal efficiency very well. Parametric studies reveal that the model predictions are sensitive to a stability parameter, the turbulent energy density in the flotation cell, the contact angle between the solid particle and fluid, and the ratio of initial-to-critical film thickness.     

Modeling of flotation process in dispersed systems

Mathematical model of flotation in dispersed mixture of liquid, solid, and gas phases has been designed within the considerations of the mechanics of multiphase media with the assumption of the degree of mineralization of the bubble surface. The application of the designed model has been demonstrated based on the example of one-dimensional stationary flotation and it has been shown that the equations that describe the emergence of bubbles are singularly disturbed (“rigid”). The effect of size and concentration of bubbles, as well as volume content of dispersed particles, on flotation has been analyzed.     

湿法脱硫系统动态过程建模与仿真

针对石灰石-石膏法烟气脱硫建立脱硫塔的化学机理模型,对塔内烟气脱硫的化学过程进行动态模拟与仿真。基于脱硫塔内物料平衡和化学平衡,将模型描述为微分方程,并通过计算软件求解。基于某电厂脱硫系统实际运行数据,预测一定时间内脱硫系统各项指标的变化,如pH、脱硫率等,以及一些重要化学物质的轴向空间分布情况,如H⁺、SO₂。根据计算结果,分析pH对脱硫率的影响规律,探究和寻找运行参数的边界条件。研究结果对实际脱硫塔的设计和运行提出了优化建议,比如在烟气入口处加强防腐措施,控制浆液pH在4.2～5.3。     

一次浮选作业泡沫分室处理工艺在淮北选煤厂浮选系统改造中的应用

介绍了淮北选煤厂(南区)浮选入料特性,分析了一次浮选作业分室泡沫的粒度组成以及沉降过滤式离心机脱泥的局限性;将煤泥二次浮选、精煤泥二段脱水工艺流程进行了优化,即一、二室粗选泡沫由沉降过滤式离心脱水机脱水、脱泥,三、四室粗选泡沫直接由二次浮选作业精选,有效提高了精煤产率。     

3-甲基丁酮分离工艺模拟

本研究通过对3-甲基丁酮合成液的剩余曲线图的分析，提出该合成液的分离流程，并用ASPEN PLUS软件对此分离流程进行模拟。模拟结果表明此流程可以得到高纯度的产品，且3-甲基丁酮和丙酮收率较高。     

硼酸与硫酸镁分离过程中浮选工艺的研究与应用

在硫酸分解硼镁矿法生产硼酸过程中,会伴生一定当量的母液,母液中的硼酸和硫酸镁的分离通常没有很好的办法来解决。研究了用浮选工艺分离经过浓缩后的硼酸母液中硼酸和硫酸镁,有效地分离出硼酸和硫酸镁,并且完成该工艺工业化生产。     

细粒煤浮选磁选联合脱灰脱铁试验研究

为获得满足工业硅生产所需的低灰低铁烟煤,以云南省某煤矿细粒煤泥为试验对象进行磁选、浮选单独脱铁脱灰试验研究,获得最佳磁选、浮选条件,并在此基础上进行浮选磁选联合脱灰脱铁试验。结果表明：磁场强度为1.701 T、煤泥粒度为-0.25 mm时,煤泥磁选、浮选效果较好,可获得相对较高的脱铁率和脱灰率。通过对比先浮选后磁选及先磁选后浮选2种试验流程及分选效果,最终选用先浮选后磁选试验流程,该流程中浮选精煤只需简单调浆即可直接用于磁选,省去了一次过滤,经济效益显著。控制精煤产率在62.08%时,能获得灰分5.94%、铁含量0.28%的合格精煤,达到了工业硅冶炼用烟煤灰分〈6%、铁含量〈0.3%的要求。     

A Reynolds mass flux model for gas separation process simulation:I. Modeling and validation

Separation process undertaken in packed columns often displays anisotropic turbulent mass diffusion. The aniso-tropic turbulent mass diffusion can be characterized rigorously by using the Reynolds mass flux (RMF) model. With the RMF model, the concentration and temperature as well as the velocity distributions can be simulated numerical y. The modeled Reynolds mass flux equation is adopted to close the turbulent mass transfer equation, while the modeled Reynolds heat flux and Reynolds stress equations are used to close the turbulent heat and mo-mentum transfer equations, so that the Boussinesq postulate and the isotropic assumption are abandoned. To val-idate the presented RMF model, simulation is carried out for CO2 absorption into aqueous NaOH solutions in a packed column (0.1 m id, packed with 12.7 mm Berl saddles up to a height of 6.55 m). The simulated results are compared with the experimental data and satisfactory agreement is found both in concentration and temper-ature distributions. The sequel Part II extends the model application to the simulation of an unsteady state ad-sorption process in a packed column.     

BGL炉煤气化过程建模和模拟

建立了BGL气化炉的三维非稳态煤气化模型,模型考虑煤炭颗粒的收缩过程,应用收缩核模型集成煤热解模型、气相湍流模型、气固流动模型、气固异相反应模型、气相均相反应模型、能量守恒方程以及相间传热模型等。该模型充分考虑了气化炉内部三维空间的温度和组成分布,通过煤热解段模型化学计量参数优化,得到CO/H₂摩尔比在1.59左右,符合BGL炉热解段运行机制;然后对BGL炉气化段过程进行三维非稳态模拟,模拟出口气组成(CO,H₂,CO₂,CH₄,H₂O,O₂)与文献结果对比,误差均小于4%。证明了BGL模型的准确性。基于该模型,本文对煤气化过程的主要参数进行影响分析。分析结果表明:煤气化效率随汽氧比的增加而提高,当汽氧比确定在1～1.3之间可以满足工艺要求及生产的需要,适合本文研究所用褐煤的特点;氧煤比增加会降低煤气化效率,但合成气中有效气的含量呈现出先增大后减小的趋势,当氧煤比在0.17左右时有效气含量达到峰值;随着煤粒直径的增加,BGL炉内的温度呈降低趋势,最高温度从...     

生产模拟系统在磷矿浮选行业上的应用

在磷矿浮选现行生产工艺控制的基础上,结合工具软件的应用,把生产控制的过程变量数据化,最终实现磷矿浮选不同关键控制要点的模块化应用,使生产人员能通过模拟系统的运行,根据各生产工序的关键数据指标及时作出生产调整,以保证生产的精矿达到最优经济效益,使磷矿资源有最好的回收率。     

某磷块岩正-反及双反浮选工艺分析

采用正-反浮选工艺及双反浮选工艺对原矿P2O5品位为25%左右,MgO品位为4%左右的某中等品位硅钙质胶磷矿进行了连续性扩大试验,正-反工艺取得了磷精矿P2O5品位31.82%左右,MgO品位0.73%左右,收率83.71%的浮选指标,双反工艺取得了磷精矿P2O5品位31.10%左右,MgO品位0.57%左右,收率88.18%的浮选指标.     

浮钨尾矿萤石的活化与浮选分离

针对我国某地浮钨尾矿中萤石被强烈抑制的特点,对萤石纯矿物及实际矿进行了浮选试验研究,开发出能有效恢复萤石可浮性的新型活化剂ANF-1,通过“一粗七精”的浮选流程,从含CaF224.93％的浮钨尾矿回收萤石,可获得含CaF2 95.03％的萤石精矿,CaF2回收率达62.13％.     

Modeling and simulation of a sulfolane extraction process

Modeling and simulation for a sulfolane extraction process were performed. The process investigated in the present work consists of two tray columns, one of which is used for extraction and the other one for washing. The modified θ-method was employed for the modeling of the process. The computation of the equilibrium state of a two-phase system is one of the key issues in the modeling and simulation of extraction processes. In the present work the UNIFAC method was used for the computation of related thermodynamic properties and equilibrium states. Results of simulations showed good agreement with actual plant operation data.     

Zn2+存在体系中菱锌矿与石英浮选分离的研究

以油酸钠为捕收剂,通过单矿物浮选试验、ξ-电位测试、吸附量测定及溶液化学分析,研究了水玻璃与六偏磷酸钠对Zn2+存在体系中菱锌矿与石英浮选分离的影响,并对其机理进行了讨论.结果表明,难免离子Zn2+对石英的活化是二者不能分离的主要原因.在矿浆中优先加入水玻璃,无法使二者有效分离;六偏磷酸钠的加入,可以明显减弱捕收剂在石英表面的吸附,使其可浮性显著下降,增大与菱锌矿的可浮性差异,从而实现菱锌矿与石英的分离.     

乙烯深冷分离中变温冷却过程制冷系统的设计与优化

根据乙烯装置中的用冷需求,将乙烯装置的深冷分离过程分为变温冷却过程和定温冷凝过程,变温冷却过程指的是裂解气的预冷过程,定温冷凝过程指的是乙烯装置中各塔塔顶冷凝器中的换热;分析了乙烯-丙烯复叠制冷系统的换热集成曲线,可知在裂解气的预冷阶段,冷热物流换热温差大。提出一种组合制冷系统,它集成了纯工质复叠制冷和混合冷剂制冷,其中的多元混合冷剂制冷系统为乙烯深冷分离的变温换热过程提供冷量。并用Aspen Plus软件对混合冷剂系统进行建模,使用遗传算法优化,优化结果表明在替代原制冷系统6895.5 kW冷量负荷的情况下,功耗降低521.6 kW,节能14.7%。     

Modeling and simulation of mechanical-thermal-diffusional-reactional interactions in ceramic oxidation process

The multi-field coupling problem in ceramic oxidation considering the effects of force, heat and chemistry involves complex dynamic process of multi-component substance in an open system. This work developed a fully-coupled mechanical-thermal-diffusional-reactional constitutive model to characterize the complex interactions among the effects. The concept of inertial effects was used to describe the dynamic of the multiple fields with finite propagation velocity. The contributions of mass diffusion and chemical reaction were separated to consider their different influential mechanisms. The weak forms of the governing equations were derived by using the chemical Gibbs function variational principle that was established based on the universal variational principle of thermodynamics. The model has the ability in predicting the concentration and entropy jump conditions on the moving interface. To verify the proposed model, the oxidation processes of Si₃N₄ and SiC were numerically calculated, by which the evolutions of oxide thickness and stress were presented. The results agree with the reference results, indicating that the model is able to reflect the evolution laws of the stress field, concentration field, temperature field and displacement field of Si₃N₄ and SiC under the coupling effect of multi-physical fields.     

Modeling and monitoring of multimode process based on subspace separation

In the paper, a new process monitoring approach is proposed for handling the multimode monitoring problem in the industrial batch processes. Compared to conventional method, the contributions are as follows: a new method of extracting the common subspace of different modes is proposed based on the subspace separation; after that the two different subspaces are separated, the kernel principal component models is built for the common and specific subspace respectively and the monitoring is carried out in subspace. The monitoring is carried out in the subspaces. The corresponding confidence regions are constructed according to their models respectively.     

变压精馏分离甲醇-丙酮的工艺模拟及优化

采用Aspen Plus软件,以塔釜能耗为目标,以甲醇、丙酮纯度为约束函数,对双效变压精馏分离甲醇-丙酮工艺过程进行模拟。分析了操作压力、理论板数、回流比、进料位置和进料温度等参数对精馏过程的影响。确定了最优工艺参数：减压塔操作压力40 kPa,理论板数37,回流比2.4,进料塔板数26,进料温度25 ℃;常压塔理论板数30,回流比4.2,进料塔板数23。减压塔所得甲醇质量分数为99.0%,常压塔所得丙酮质量分数为99.7%。对比变压精馏和萃取精馏过程,变压精馏更容易得到高纯度丙酮产品,节能约13.4%。模拟结果对工业设计和设备改造具有一定指导意义。