Microstructures and properties of Al-45%Si alloy prepared by liquid-solid separation process and spray deposition

The microstructures and properties of A1-45%Si alloy prepared by liquid-solid separation （LSS） process and spray deposition （SD） were studied. The results show that the size, shape and distribution of the primary Si phase have different influence on the properties of alloys. Comparing with the Si particles with irregular shape, fine size and continuous distribution in SD alloy, the primary Si phase in LSS alloy is sphere-like, coarse and surrounded by the continuous AI matrix. The microstructure features of LSS alloy are beneficial to the higher thermal conductivity and lower thermal expansion coefficient at room temperature. The fine Si particle in SD alloy is advantageous to improving the mechanical properties. The increasing rates of thermal expansion coefficient with temperature are influenced by the distribution of the Si particles, where a lower rate is obtained in SD alloy with continuous Si particles. The agreement of thermal expansion coefficient with the model in LSS alloy differs from that in the SD alloy because of the different microstructure characteristics.

Microstructure and properties of SiC_p/Al electronic packaging shell produced by liquid-solid separation

The electronic packaging shell of high silicon carbide （54%SiC, volume fraction） aluminum-based composites was produced by liquid-solid separation technique. The characteristics of distribution and morphology of SiC as well as the shell’s fracture surface were examined by optical microscopy and scanning electron microscopy, and the thermo-physical and mechanical properties of the shell were also tested. The results show that Al matrix has a net-like structure while SiC is uniformly distributed in the Al matrix. The SiCp/Al composites have a low density of 2.93 g/cm^3, and its relative density is 98.7%. Thermal conductivity of the composites is 175 W/（·K）, coefficient of thermal expansion （CTE） is 10.3×10^-6 K-1 （25-400 ℃）, compressive strength is 496 MPa, bending strength is 404.5 MPa, and the main fracture mode is brittle fracture of SiC particles accompanied by ductile fracture of Al matrix.Its thermal conductivity is higher than that of Si/Al alloy, and its CTE matches with that of the chip material.

Removal of Silica and Alumina as Impurities from Low-Grade Iron Ore Using Wet High-Intensity Magnetic Separation and Reverse Flotation

This study investigates the removal of silica and alumina as impurities from hematite based low-grade iron ore containing 34.18 mass% iron, 31.10 mass% of silica and 7.65 mass% alumina. Wet high-intensity magnetic separation (WHIMS) and reverse flotation (RF) were investigated. In WHIMS process, 93.08% of iron was recovered with a grade of 53.22 mass% at an optimum magnetic density of 10,000 mT, and pulp density of 2% used the L-4 machine. In RF experiments, optimal results showed 95.95% of iron recovered with 51.64 mass% grade using 1 kg/t of 1% alkaline starch as iron depressant and 1:1 mixture ratio of 0.75 kg/t DAA and NaOL as silica and alumina collectors. The designed multi-stage process involving feeding the concentrate from WHIMS into RF process reduced silica to 2.02 mass%, alumina to 1.04 mass% whilst recovering 81.94% of the iron with 67.27 mass% grade. As a result of this research, a process to produce high quality iron concentrate from hematite based low-grade iron ore with high iron recovery rate was constructed.

Study on Separation of Pb and Zn from Mixed Rougher Concentrates

The compositions of Pb and Zn mixed rougher concentrates were studied. The process utilizes flotation and gravity flow sheet to separate Pb or Zn. Pb and Zn in the tailings were reclaimed by gravity more efficiently. This test used an ion-wave shaking table developed by Kunming University of Science and Technology. Based on the test results, the optimum test condition was chosen and testing of synthetic condition was performed. The results show that the process produces a final Zn concentrate with a 42.16% grade and 79.64% recovery and a final Pb concentrate with a 46.52% grade and 78.41% recovery.

Liquid-solid phase separation and recycling of permalloys in liquid Mg

Liquid-solid phase separation of permalloy in liquid Mg results in selectively dissolved Ni,which provides a unique opportunity for the design of immiscible heterogeneous composite materials and the comprehensive metal recycling of permalloy scraps.A guideline of the alloy design for the liquid-solid phase separation system was proposed.The effects of immersion temperature and time on the Ni extraction were studied by an experimental method.The diffusion behavior of Ni from the permalloy to liquid Mg and the microstructure evolution in the permalloy during the liquid-solid phase separation were discussed.The results show that the Ni in the permalloy was quickly extracted into the liquid Mg and formed an Mg-Ni alloy,while the other components such as Fe,Co,and Mn were held back in the phase-separated permalloy.The phase-separated permalloy with the solidified Mg exhibits a three-dimensional(3D)Fe/Mg bicontinuous composite structure.Furthermore,simple treatments were carried out for the reaction products such as the Fe/Mg bicontinuous composite and the Mg-Ni alloy,and the recycling strategies for functionalization of these treated reaction products were provided.A 3D porous Fe-based alloy with electromagnetic interference(EMI)shielding efficiency of 52 dB can be obtained if Mg is removed from the Fe/Mg bicontinuous composite.Instead of the complete separation of pure Ni from the recycled Mg-Ni alloy by vacuum distilling,the Mg-Ni alloy can be enriched into Mg2 Ni as an initial hydrogen storage material.

含磁黄铁矿型硫铁矿选矿技术研究

内蒙古某硫铁矿含硫23.66%、含铁32.26%,为了开发利用该矿产资源,对其进行原矿性质研究和选矿技术研究。原矿性质研究表明,该矿石主要金属矿物为黄铁矿,其次是磁黄铁矿和磁铁矿;脉石矿物主要为白云石和方解石。试验确定的原则工艺流程为“浮选-磁选”联合流程。当磨矿细度为65%-0.074 mm,硫酸铜用量为300 g/t,丁基黄药用量为230 g/t,2^(#)油用量为60 g/t时,原矿经过一次粗选、一次扫选和两次精选产出硫精矿,闭路试验获得硫精矿中硫品位为43.42%,硫回收率为85.46%;在粗选磁场强度为1300 Oe、精选磁场强度为800 Oe条件下,进行一次粗选一次精选,最终获得铁精矿中铁品位为53.76%,铁回收率为17.55%的选矿指标。

Novel uses of ensiled biomasses as feedstocks for green biorefineries

Perennial forage plants are efficient utilizers of solar radiation and nutrients so that there is a lot of scope to increase the production of green biomass in many areas.Currently,grasses are mainly used as feeds for ruminants and equines,but there could be higher added value use for several components of the green biomass.Interest in green biorefin-ing has risen recently motivated by the increased sustainability pressures and need to break the reliance on fossil fuels.Novel products derived from grass,such as paper and packaging,nanofibers,animal bedding,novel protein feeds,extracted proteins,biochemicals,nutraceuticals,bioactive compounds,biogas and biochar could create new sustainable business opportunities in rural areas.Most green biorefinery concepts focus on using fresh green biomass as the feedstock,but preservation of it by ensiling would provide several benefits such as all-year-around avail-ability of the feedstock and increased stability of the press juice and press cake.The major difference between fresh and ensiled grass is the conversion of water soluble carbohydrates into fermentation end products,mainly lactic and acetic acids,that lower the pH of the silage so that it becomes stable in anaerobic conditions.This has some important consequences on the processability and quality of products,which are partly positive and partly negative,e.g.,degradation of protein into peptides,amino acids and ammonia.These aspects are discussed in this review.

Utilization of Bubbles and Oil for Microplastic Capture from Water

The removal of microplastics(MPs)from water using oil has shown early promise;however,incorporation of this technique into a feasible in situ method has yet to be developed.Here,a simple yet effective method of MP capture from water using vegetable oil with bubbles is demonstrated to achieve high removal efficiencies of>98%.Comparisons are made with other methods of agitation,and higher removal efficiencies are observed when bubbles are used.Due to the low agitation provided by the bubbles,the oil layer remains unbroken,meaning that no oil is released into the bulk water phase.In this way,secondary contamination is avoided—unlike membrane filtration,another effective removal method,in which polymer-based membranes can break down due to chemical backwashing and ageing.It is demonstrated that variation in MP size within the micrometer range(50–170 lm)has minor impact on the removal efficiency;however,100%removal is achieved for larger,millimeter-sized MPs(500–5000 lm).Similarly,a high removal efficiency of greater than 99%is achieved in the capture of microfibers.Other factors such as oil volume and water salinity are also investigated and discussed.Based on these results,the proposed method can be introduced into multiple setting types as a passive and continuous method of MP capture.

Motion characteristics and density separation of fine coal in an inflatable-inclined liquid-solid fluidized bed

To improve the adaptability of fluidized beds for fine coal separation,a new type of liquid-solid fluidized bed was constructed,i.e.,the inflatable-inclined liquid-solid fluidized bed(IILSFB).A combination of simulation analysis and separation experiments was used to analyze the fluidization characteristics and separation performance of the IILSFB.The results showed that there was upflow and downflow in the fluidized bed.The upflow was mainly composed of water flow,followed by light and heavy particles;on the other hand,the downflow was caused by the backflow of heavy particles that settled at the inclined section.In addition,the light particles that settled at the inclined section could return to the rising water flow under the action of secondary airflow.As the water velocity,separation time,and secondary gas velocity increased,the comprehensive separation efficiency of fine coal in the fluidized bed improved,while the value decreased as the feed quantity increased.This also indicated the order of importance for these four factors,i.e.,water velocity,separation time,feed quantity,and secondary gas velocity,on fluidisation.Furthermore,the comprehensive separation efficiency of 0.1-1 mm fine coal varied significantly with various factors,while that of∼0.1 mm and 1-3 mm fine coal was always at a low value.In the latter case,the classification process of the size fraction was significantly better than the separation process in the fluidized bed.Under optimal working conditions,an IILSFB was used to separate the fine coal(0.1-1 mm).The yield of clean coal was 37.95% with an ash content of 12.11%,and the possible error was 0.085 g/cm^(3),indicating that the IILSFB had good separation performance for 0.1-1 mm fine coal.

旋流气浮一体化技术在低含油污水处理中的应用

紧凑型气浮装置将旋流分离技术与竖流式气浮分离技术有机结合,借助低强度旋流离心力场促进微细气泡与原水中待去除污染物颗粒的碰撞粘附,进而强化气浮分离过程,具有水力停留时间短、占地面积小、处理效率高和操作要求低等优点。对BIPTCFU-Ⅲ型旋流气浮一体化含油污水处理装置的结构方案、工作原理以及现场试验情况进行了介绍,并将其处理性能与CrudeSep旋流加气浮选器的处理性能进行对比。分析结果表明,当入口污水含油质量浓度在100mg/L以下时,即使不添加任何处理药剂,BIPTCFU-Ⅲ型样机连续运行可将出水口的含油质量浓度降低到20 mg/L以下,满足压力滤罐的进水水质要求。

4种漂浮法分离土壤中人蛔虫卵的效果比较

目的比较4种不同漂浮法从土壤中分离人蛔虫卵的效果,从而摸索出一种行之有效的、适用于现场的从土壤中分离人蛔虫卵的方法。方法在不含人蛔虫卵的土壤中按一定比例加入人蛔虫卵(包括受精蛔虫卵和未受精蛔虫卵),分别用4种漂浮法检查,比较检出效果。结果硫酸锌溶液漂浮法、饱和硝酸钠溶液漂浮法、饱和柠檬酸三钠溶液漂浮法及饱和盐水漂浮法的受精蛔虫卵检出率依次为6.89%、26.85%、8.46%和0.21%(F=221.45,P<0.01);总蛔虫卵检出率依次为6.29%、25.49%、7.77%和0.19%(F=223.41,P<0.01)。结论4种漂浮法均能分离出土壤中的人蛔虫卵,以饱和硝酸钠溶液漂浮法的效果最佳,且操作简便,适合大批量土壤样本的人蛔虫卵分离检查。

硫酸铵-碘化钾-乙基紫体系浮选分离Pb(Ⅱ)

研究了硫酸铵 碘化钾 乙基紫体系浮选Pb(Ⅱ )的性能及Pb(Ⅱ )与常见离子的分离。研究表明 ,在水溶液中 ,Pb(II)与I- 、乙基紫阳离子 (EV+ )生成三元离子缔合物沉淀 (PbI- 3)·(EV+ ) 2 和 (PbI2 - 4)·(EV+ ) 2 。在 0 1g/mL (NH4 ) 2 SO4 存在下 ,该沉淀能很好地浮于水相表面。在水相pH为 1 0～ 4 0时 ,通过浮选可使Pb(Ⅱ )与Zn(Ⅱ )、Mn(Ⅱ )、Fe(Ⅲ )、Co(Ⅱ )、Al(Ⅲ )、Ni(Ⅱ )

液-液萃取浮选法分离Ni(Ⅱ)、Co(Ⅱ)、Fe(Ⅲ)的研究

研究了在（ＮＨ４）２ＳＯ４存在下，乙醇与水分相的条件。试验表明，丁二酮肟与镍生成的螯合物沉淀可以被萃取浮选在乙醇与水两相之间，钴与丁二酮肟生成的螯合物被乙醇萃取，Ｆｅ（Ⅲ）留在水相中，实现了同一体系中三相分离Ｎｉ（Ⅱ）、Ｃｏ（Ⅱ）、Ｆｅ（Ⅲ），结果满意。

某高硫砷铁矿降砷工艺研究

采用先浮选后磁选方案,确定流程方案进行详细研究,研究结果表明,在充气氧化条件下实现硫砷分离,药方简单,获得较好的试验指标.

十六烷基三甲基溴化铵硫氰酸铵-氯化钠体系浮选分离钌(Ⅲ)

在水溶液中 ,Ru(Ⅲ )与硫氰酸铵、十六烷基三甲基溴化铵形成不溶于水的三元缔合物。在少量NaCl存在下 ,此三元缔合物沉淀浮于盐水相上层形成界面清晰的液 固两相 ,当溶液中硫氰酸铵、十六铵基三甲基溴化铵和氯化钠的浓度分别为 0 .2 0mol/L、1× 1 0 -3 mol/L、0 .1g/mL ,pH =5 .0时 ,Ru(Ⅲ )被定量浮选。Cr(Ⅲ )、Mn(Ⅱ )、Al(Ⅲ )、Ni(Ⅱ )、Co(Ⅱ )、Fe(Ⅱ )、Au(Ⅲ )离子在该体系中不被浮选 ,从而使Ru(Ⅲ )与这些离子定量分离 ,对合成水样进行的定量浮选分离测定 ,结果满意。

流动液体中夹杂物超声去除的影响因素

以高密度聚乙烯(HDPE)颗粒和水形成的悬浮液为研究体系,考察了有无超声波作用下．介质流量、夹杂物数量以及夹朵物的粒径对总去除率、上浮去除率、壁面粘附去除率的影响,实验结果表明．在短时间内(30 s)超声波对流动液体中的夹杂物具有明显的去除效果,总去除率达93%．夹杂物的总去除率随着超声波输入电功率的增大而提高:超声波对较多数量或较大粒径的夹杂物去除效果更显著,超声波作用下流动液体中的夹杂物比静止液体中的更容易去除,超声波对流动液体中夹杂物去除效果的去除机理主要是通过气泡捕获夹杂物、超声空化效应产生直接包裹夹杂物的气泡以及通过夹杂物碰撞凝聚使夹杂物容易上浮实现去除。

硝酸钠-碘化钾-罗丹明B体系浮选分离汞Ⅱ的研究

研究了硝酸钠 -碘化钾 -罗丹明B体系浮选分离汞 的行为和汞 与常见离子分离的条件。结果表明 ,控制溶液pH 5 0 ,当固体NaNO3用量为 1 0g ,0 1mol/L碘化钾和 0 0 0 1mol/L罗丹明B溶液的用量均为 0 5mL时 ,Hg2 + 可被定量浮选 ,而Cu2 + ,Zn2 + ,Mn2 + ,Co2 + ,Ni2 + ,Fe2 + ,Al3+ 等离子在此条件下不被浮选 ,实现了Hg2 + 与这些离子的定量分离。方法用于合成水样中微量汞 的定量浮选分离测定 。

山东某钾钠长石矿提纯工艺的试验研究

采用"磨矿—脱泥—磁选—浮选"的工艺流程,对山东某地长石矿进行精选,可以得到最终精矿中TFe2O3含量0.12%、CaO含量0.26%的技术指标,该精矿达到了我国长石产品在釉料、陶瓷白坯及平板玻璃等方面应用一级质量指标。

含油污水高效处理系统试验研究

介绍了油田含油污水处理现状、现有处理技术及其发展情况。描述了污水处理及采出液处理现场实验工艺流程及主要试验内容。试验发现 ,当入口含油浓度在 6 0 0mg/L左右时 ,旋流处理后可降到 6 0mg/L ,再经气浮处理可降到 2 0mg/L左右 ;当入口含油在 2 5 0 0mg/L左右时 ,旋流处理后可降到 6 0 0mg/L ;若经气浮处理可降到 2 5 0mg/L左右。实际应用中应根据客观条件合理选择分离设备及其配套设备 。

硝酸钠-硫氰酸铵-溴化十六烷基三甲基铵体系浮选分离铂

研究硝酸钠存在下,溴化十六烷基三甲基铵-硫氰酸铵体系浮选Pt(Ⅳ)的行为及与一些金属离子分离的条件.实验结果表明,当溶液中溴化十六烷基三甲基铵、硫氰酸铵、硝酸钠的浓度分别为4.0×10-3mol.L-1、3.0×10-2mol.L-1、0.05 g.mL-1,pH4.0时,Pt(Ⅳ)可与Co(II)、Mn(II)、Al(Ⅲ)、Ni(II)、Ga(Ⅲ)、Fe(II)离子定量分离,该方法用于Ni-Pt/Al2O3催化剂中铂的分离和测定,Pt的含量7次平均值为0.095 2%,RSD为2.2%.