粗砂在生料浆配制中的再利用

山西分公司将拜耳法高压溶出矿浆分离出的粗砂送烧结法配料，本文对粗砂的物理化学特性进行分析，提出了相应的配料方案。     

粗砂在生料浆配制中的再利用

山西分公司将拜耳法高压溶出矿浆分离出的粗砂送烧结法配料,本文对粗砂的物理化学特性进行分析,提出了相应的配料方案。     

降低拜尔法粗砂产出的途径

为了提高拜尔法沉降槽的生产能力，减轻粗砂对沉降及过滤系统泵的磨损，以确保高压溶出的稳产高产，山西分公司对高压溶出稀释矿浆进行粗颗粒分离，除去粗砂，粗砂返回烧结法配料，增加了生产成本。本文就粗砂的产出原因，结合分公司生产实际，从矿浆细度、溶出温度、溶出时间等影响溶出效果的主要因素做以分析研究，提出了利用格子磨一旋流器新工艺改善矿浆细度，改进不凝性气体排放方式，完善溶出机组，开发水力除疤技术等改进措施，以大幅提高溶出效果，减少粗砂的产出，为企业创造较好的经济效益。     

减少拜尔法生产中粗砂产出的途径

为了提高拜尔法沉降槽的生产能力,减轻粗砂对沉降及过滤系统泵的磨损,以确保高压溶出的稳产高产,中国铝业山西分公司对高压溶出稀释矿浆进行粗颗粒分离,除去粗砂,粗砂返回烧结法配料,增加了生产成本。本文就粗砂的产出原因,结合分公司生产实际,从矿浆细度、溶出温度、溶出时间等影响溶出效果的主要因素进行分析研究,提出了利用格子磨-旋流器新工艺改善矿浆细度,改进不凝性气体排放方式,完善溶出机组,开发水力除疤技术等改进措施,以大幅提高溶出效果,减少粗砂的产出,为企业创造较好的经济效益。     

锌冶金企业原料配料系统的优化方法的探讨与实践

提出了锌冶炼企业原料配料系统的优化方法，并引入了狭义配料和广义配料两个概念。建立数学模型探讨配料及其采购过程中成本最优问题，对生产的配料和采购过程成本进行初步约束，并进行结果分析和经济效益分析，实现配料向质量成本和采购成本最优的方向运行。     

申克烧结配料技术的引进与消化

介绍了邯钢400m^2烧结机配料采用德国申克配料技术的情况，分析了申克配料技术的优缺点，并根据生产实践对其进行了部分改进。     

差值流量电子皮带秤技术在烧结配料的应用

介绍了采用差值流量电子皮带秤技术进行配料的系统组成、控制原理及设备特点。该系统在重量配料法的基础上，对配料控制模式进行了改造，并取得了良好的效果。     

申克烧结配料技术的引进与消化

邯钢400m^2烧结机配料采用德国申克配料技术。本文分析介绍了申克配料技术的优缺点，并根据生产实践情况对其进行了部分改进。     

配料秤在包钢烧结厂的应用

论述了烧结配料过程中的检测技术，标定的方法及自动配料的方式，并对现有的问题进行了说明。     

烧结配料调整策略探讨

对马钢三烧结厂有代表性的质量情况的分析中，通过计算并模拟实际配料调整的结果，得出了现有生产情况下，烧结矿碱度出格时，以１００％幅度进行配料调整的成功率最高，达６８％。为统一配料操作思想提供了理论依据。     

不同粗骨料对膏体凝结性能的影响及配比优化

甘肃金川铜镍矿似膏体充填料浆水化凝结时间迟缓、粗骨料离析程度大,严重影响充填浆体的质量。本文以金川二矿区全尾砂、废石和棒磨砂为实验材料,采用全面实验设计法,研究不同质量分数、粗骨料及尾骨比（全尾砂与粗骨料质量比）对膏体充填凝结性能、抗压强度和流变特性的影响规律。实验结果表明:全尾砂–粗骨料膏体中,粗骨料的比表面积和化学成分（活性MgO和CaO）是影响凝结时间的主要因素;凝结时间随尾骨比增加而缩短,屈服应力随尾骨比增加而增加,塑性黏度（全尾砂–废石、全尾砂–棒磨砂膏体）随尾骨比增加而增加;全尾砂–废石膏体抗压强度优于全尾砂–废石–棒磨砂膏体抗压强度;最短凝结时间及最佳抗压强度（全尾砂–废石膏体、尾骨比5∶5）比矿用凝结时间和抗压强度分别缩短2.1 h和增加33%以上。最后对凝结性能进行单目标及多目标回归优化,多目标回归优化表明:全尾砂–废石–棒磨砂膏体最佳凝结时间为270～300 min、尾骨比10∶6∶6～10∶7∶7、屈服应力为167.0～169.0 Pa;全尾砂–棒磨砂膏体最佳凝结时间为300～330 min、尾骨比10∶14～10∶16、屈服应力为164.0～167.0 Pa,满足矿山生产要求。      

菲律宾某含磁铁矿海砂磁选试验研究

菲律宾某海砂以钛磁铁矿为主,且粒度分布较粗,针对该特点,采用预先筛分-磁选-磨矿分级-磁选的工艺,从含铁7.18%的原矿中获得了含铁59.03%、回收率为32.31%的铁精矿,使该海砂得到充分利用。     

Contact Erosion at the Interface between Granular Coarse Soil and Various Base Soils under Tangential Flow Condition

Under embankment dams and dykes, horizontal groundwater seepage prevails. If the subsoil is layered, and if some coarse layers are not appropriate filters for finer layers, there can be contact erosion at the interface between fine and coarse soils. In order to study contact erosion threshold, some base-soil and coarse-soil combinations were submitted to a flow parallel to the interface between the coarse soil and the base soil. Critical velocities and critical hydraulic gradients were measured for various base soils. Using effective base-soil grain diameter, an empirical expression for critical velocity was proposed that is well adapted for silts or sand/clay mixtures as well as for sands. The mass of eroded soil was measured relative to the flow velocity for each base-soil/coarse-soil setup. The shear stress applied to the interface between base soil and coarse soil was derived from the hydraulic gradient. Using an empirical relationship between applied shear stress and measured eroded mass, erosion rate was estimated for each base-soil/coarse-soil setup.     

平底型立式砂仓在毛家寨铁矿的应用研究

目前矿山充填系统在使用尾砂作为充填材料时,常用立式砂仓来完成浓缩、脱水和造浆任务。常用的立式砂仓底部结构为锥体型、半球体型或多锥体型,采用高压喷水嘴局部流态化造浆,来实现高浓度排放。当对粒度组成较细的全尾砂进行浓缩脱水时,浓缩后的浆体粘度大,造浆和排放效果变差。毛家寨铁矿尾矿粒度组成较细,不能使用常用的立式砂仓,设计使用了平底型立式砂仓,有效防止了浆体在仓内的粘结淤积,使全尾砂实现了稳定的高浓度浆体排放并获得合格回水。     

Wave Attenuation over a Rigid Porous Medium on a Sandy Seabed

In this study, an analytic solution of wave interaction with a rigid porous medium above a poro-elastic sandy bottom is derived to investigate the attenuation of the surface wave and the wave-induced soil response. In the model, both inertial and damping effects of the flow are considered in the rigid porous region using the potential theory, while the consolidation theory is adopted in the sand region. A new complex dispersion relation involving parameters of the rigid porous and the poro-elastic medium is obtained. The analytic solutions are verified by some special cases, such as wave interaction with a porous structure over an impermeable bottom or wave interaction with a poro-elastic medium only. Numerical results indicate that the wave attenuation is highly dependent upon the thickness of the rigid porous layer, the soil stiffness, and their respective coefficients of permeability. Increasing the thickness of the rigid porous layer will shorten the wavelength of the surface wave regardless of the sand coarseness. The pore pressure in fine-sand is larger than in coarse sand, with both decaying with wave progression. It is also found that increasing the thickness of the rigid porous medium will effectively reduce the pore pressure in the sand. For the applications, an extended hyperbolic mild-slope equation is finally obtained, based on the basic analytic solutions. Examples of the wave height transformation over submerged permeable breakwaters on a slope sandy seabed are given. The simulated results show that the wave decay of the coarse sand seabed is larger than those of fine-sand and impermeable seabeds when waves pass after the submerged porous breakwater. The wave damping versus the friction factor for various height of the submerged breakwater is discussed.     

Capillary Barrier Effect from Underlying Coarser Soil Layer

Infiltration tests were conducted on soil columns of silty sand over pea gravel, concrete sand over pea gravel, and silty sand over concrete sand to investigate the capillary barrier effect of an underlying coarser soil layer. Water movement across the interface occurred when the suction head at the interface reached the breakthrough head of the coarser lower soil layer, defined as the suction head at which the coarser layer first became conductive, regardless of infiltration rate or the properties of the overlying finer soil layer. Thus, the coarser lower soil layer controlled breakthrough in this study. After infiltration was terminated, the suction head near the interface increased above the breakthrough head and the barrier was restored. The breakthrough head did not change substantially after eight test cycles of breakthrough and restoration for a capillary barrier with a pea gravel as the coarser lower soil layer. The barrier formed with the concrete sand as the coarser layer permitted breakthrough at a greater suction head than did the barrier with the pea gravel, indicating that the more uniform and coarse the lower soil layer is, the more effective the capillary barrier.     

Undrained Fragility of Clean Sands, Silty Sands, and Sandy Silts

In this paper, intergranular (ec) and interfine (ef) void ratios and confining stress are used as indices to characterize the stress–strain response of gap graded granular mixes. It was found that at the same global void ratio (e) and confining stress, the collapse potential (fragility) of silty sand increases with an increase in fines content (FC) due to a reduction in intergranular contact between the coarse grains. Beyond a certain threshold fines content (FCth), with further addition of fines, the interfine contact friction becomes significant. The fragility decreases and the soil becomes stronger. The value of FCth depends on e and the characteristics of fines and coarse grains. At FCFCth), fine grain friction plays a primary role and dispersed coarse grains provide a beneficial, secondary reinforcement effect. At the same ef, the collapse potential decreases with an increase in sand content. Beyond a certain limiting fines content, the soil behavior is controlled by ef only. An intergranular matrix diagram is presented that delineates zones of different behaviors of granular mixes as a guideline to determine the anticipated behavior of gap-graded granular mixes. New equivalent intergranular contact void ratios, (ec)eq and (ef)eq, are introduced to characterize the behavior of such soils, at FCFCth, respectively.     

石灰和废旧镁砂在非真空感应炉脱磷实验应用

利用石灰和废旧镁砂在非真空感应炉冶炼形成脱磷炉渣;通过两种方案试验的对比,加入少量的废旧镁砂既提高了脱磷率又减轻了冶炼负担还提高了炉龄。并对非真空感应炉的实际操作提供了一些基础数据。     

Modeling of Evaporation Reduction in Drip Irrigation System

Surface drip irrigation is an efficient system for delivering water to crops; however, conditions at the soil surface affect evaporation rate and efficiency. A method is proposed, sand tube irrigation (STI), to increase the efficiency of drip irrigation systems. This method is specific to permanent tree crops where soil is not tilled or turned. The STI method consists of removing a soil core beneath the emitter and filling the void with coarse sand. The SWMS??2D model, implemented in a 3D axisymmetric form, was used to simulate infiltration, water redistribution, evaporation from the soil surface, and rise of water inside the sand tube. Model simulations were compared with laboratory measurements determined from a weighing lysimeter. The simulated values of water height inside the sand tube and temporal position of the wetting front in both lateral and upward directions closely matched the experimental measurements. The advancement of the wetting front in the downward direction and evaporation estimates was predicted with less accuracy. Experiments showed that relative to surface drip irrigation, the STI method reduced evaporation by approximately 26% over a 4-day period.     

Visualization and Simulation of Asphalt Concrete with Randomly Generated Three-Dimensional Models

The objective of this study is to visualize and simulate microscale properties of asphalt concrete with three-dimensional discrete element models under mechanical loading. The microstructure of the asphalt concrete sample was composed of three ingredients: coarse aggregates, sand mastic (a combination of fines, fine aggregates, and asphalt binder), and air voids. Coarse aggregates were represented with the irregular polyhedron particles which were randomly created with an algorithm developed for this study. The gaps among the irregular particles were filled with air voids and discrete elements of sand mastic. The mechanical behaviors of the three ingredients were simulated with specific constitutive models at different contacts of discrete elements. Based on the geometric and mechanical models, visualization and simulation of asphalt mixtures were conducted in this study.