Separation of halogens and recovery of heavy metals from secondary copper smelting dust

The separation of halogens and recovery of heavy metals from secondary copper smelting(SCS)dust using a sulfating roasting−water leaching process were investigated.The thermodynamic analysis results confirm the feasibility of the phase transformation to metal sulfates and to gaseous HF and HCl.Under the sulfating roasting conditions of the roasting temperature of 250℃ and the sulfuric acid excess coefficient of 1.8,over 74 wt.%of F and 98 wt.%of Cl were volatilized into flue gas.Approximately 98.6 wt.%of Zn and 96.5 wt.%of Cu in the roasting product were dissolved into the leaching solution after the water leaching process,while the leaching efficiencies of Pb and Sn were only 0.12%and 0.22%,respectively.The mechanism studies indicate the pivotal effect of roasting temperature on the sulphation reactions from various metal species to metal sulfates and the salting out reactions from various metal halides to gaseous hydrogen halides.

Monazite Recovery by Magnetic and Gravity Separation of Medium Grade Zircon Concentrate from Senegalese Heavy Mineral Sands Deposit

Gravity, magnetic and electrostatic separation methods allowed to obtain different titanium oxide concentrates (ilmenite, leucoxene, rutile) and different varieties of zircon concentrates (premium zircon, standard zircon, medium grade zircon standard) from Senegal’s heavy mineral sands. During mining separation, monazite, which is a paramagnetic mineral, was found in a non-negligible concentration of 0.57 wt% on average in the medium grade zircon standard which also contains 37.96 wt% zircon and 44.46 wt% titanium oxides. Magnetic and gravity separation tests were carried out on the Medium grade zircon standard (MGZS) to produce a monazite concentrate at Eramet Ideas laboratory. Magnetic separation at 1.5 teslas intensity resulted in the recovery of 94.8% of the monazite from the MGZS. Gravity separation also recovered 76.6% of the monazite from the MGZS. The combination of these two treatment methods can thus produce three concentrates from MGZS (a monazite concentrate, a zircon concentrate, and a titanium oxide concentrate).

Separation of Toluene Insoluble Matter from Syncrude Coker Heavy Gas Oil

Toluene insoluble matter (TIM) in coker heavy gas oil (CHGO) from oil sands bitumen is harmful to the downstream hydrotreating, and it may be difficult to be removed by conventional filtration. In order to determine its origin, the TIM must first be separated from CHGO for characterization. Two techniques are described to accomplish this goal. In the ultra-centrifugation approach used in this work, CHGO is blended with a miscible liquid and centrifuged under 366000 G (gravity) force. Through this procedure toluene and hexane diluents yielded TIM contents of 24μg·g-1 and 88μg·g-1 respectively. In an alternative simplified procedure, the initial ultra-centrifugation step is omitted. Several different solvents are evaluated for use as diluents but, in each case, toluene is still used in the subsequent washing steps. TIM contents determined by this method range from 23 to about 200μg·g-1. The amount of TIM separated by means of this method depends primarily on the initial diluent used. Other conditions, such as diluent-oil ratio, water-oil ratio, mixing time, temperature and water pH value, are also studied.

Performance of Inner-core Supersonic Gas Separation Device with Droplet Enlargement Method

To improve the separation performance of a supersonic gas separation device for the treatment of gas mixture with a single heavy component, a novel structure with shorter settlement distance was constructed and a method of droplet enlargement was applied. A series of experiments were carried out in the improved separation device under various conditions, using air-ethanol vapor as the medium and micro water droplets as nucleation cen- ters. The effects of the inlet pressure, temperature and relative humidity, the swirling intensity, and mass flow rate of water on the separation performance were investigated. The separation was improved by increasing the inlet pressure and relative humidity. With the decrease of swirling intensity and mass flow rate of water, the separation efficiency increased first and then decreased. The inlet temperature had a slight effect on the separation. The results showed that the separation performance was effectively improved using the proposed structure and method, and the best separation in this study was obtained with the ethanol removal rate about 55% and dew point depression 27 K. The addition of water had little pollution to the air-ethanol vapor system since the water carry-over rate was within the range of -2 %-0 in most cases.

Recovery and Upgrading of Phosphorus from Digested Sewage Sludge as MAP by Physical Separation Techniques

Physical separation apparatuses;a vibrating screen, a 4-inch hydrocyclone and a Multi-Gravity Separator (MGS) were used to recover phosphorus as MAP (magnesium ammonium phosphate, MgNH4PO4.6H2O) from anaerobic digested sludge of two sewage-treatment plants A and B. For plant A, the MAP grade increased from 0.08% to 88.9% with 90.4% recovery and for plant B, the grade increased from 0.11% to 73.8 with 93.2% recovery. The collected MAP products containing impurities such as organic materials and heavy metals were further upgraded through dry and wet magnetic separation tests at different magnetic flux densities. A dry magnetic separator was tested on both MAP products (MAP-A and MAP-B), while the wet magnetic separation process was exclusively experimented for the removal of impurities from MAP-B. Feed samples, as well as magnetic and nonmagnetic products were analyzed by absorption spectroscopy, XRD, ICP-AES, polarizing microscope observation, and SEM-EDX. The grade of MAP products could be improved by about 4% - 9% after magnetic separation (the most appropriate magnetic force being 15,000 Gauss). During both dry and wet magnetic separation processes, not only heavy metals have been removed, but also nonmagnetic constituents like Al, Ba, and Ca. This may be attributed to the attachment of fine magnetic particles on the nonmagnetic surfaces, rendering them magnetic properties.

Separation of protactinium in the reaction of 60MeV/nucleon ^(18)O ions with natural uranium

The activities of protactinium were produced by the multi-nucleontransfer reactions in bombardment of the natural uranium with 60 MeV/nucleon 1sOions. A simple, relatively fast radiochemical procedure was used for extraction sep-aration of protactinium from the uranium and a variety of reaction products using1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and tri-iso-octylamine as extractants. Theγ ray spectrum of the separated protactinium fractions showed that the protactiniumcould be separated from all of the main impurity elements. The decontaminationfactors of the uranium and the main reaction products produced in the reaction aregiven.

Distribution of calcium, nickel, iron, and manganese in super-heavy oil from Liaohe Oilfield, China

Liaohe super-heavy crude oil was separated into its components, namely saturates, aromatics, resins, and asphaltenes （SARA）, by the group separation method. Several solvents were used to extract different forms of metallic elements from crude oil. The metallic elements, such as calcium, nickel, iron and manganese, in crude oil, SARA and extract samples were analyzed by inductively coupled plasma atomic emission spectroscopy （ICP-AES）. The results demonstrate that the contents of calcium, nickel, iron, and manganese gradually increase in saturates, aromatics, resins, and asphaltenes, suggesting that the abundance of the four metallic elements in asphaltenes is much higher than that in the other groups. For example, the content of calcium in asphaltenes reaches a maximum of 7,920 pg/g. Among the SARA components of Liaohe super-heavy crude oil, resins account for more than 50 wt%, suggesting that the total amount of the four metallic elements are higher in the resin component than in other components. The four metallic elements mainly exist in the form of organic metallic compounds in crude oil. Further analysis shows that calcium and manganese elements exist mainly as metal salts of petroleum acids, and the majority of the iron and all the nickel exist mainly as metalloporphyrin and non-metalloporphyrin compounds.

四川某锂辉石废石重介分选

这是一篇矿物加工工程领域的文章。研究对象为四川某锂辉石废石,根据该锂辉石废石的矿物特性,对该锂辉石废石三种不同入料粒度(-15+0.5 mm、-10+0.5 mm、-5+0.5 mm)分别进行实验室重液分选实验,实验结果表明,该锂辉石废石采用重液分选效果较好,且以-10+0.5 mm作为后续重介实验的入料粒度范围,并选择2.70 g/cm^(3)作为分选密度时,重液分选指标相对较好,但根据实际生产重介分选实验结果,最终在入选粒度为-15+0.5 mm,介质密度为2.0 g/cm^(3)时,分选指标相对较好。

多离子印迹膜的制备及其吸附性能研究

以Zn^(2+)、Co^(2+)、Cr^(3+)和Pb^(2+)为混合模板,双硫腙为螯合剂,APTES为功能单体,TEOS为交联剂,PVDF为基膜,采用凝胶溶胶法成功合成了对模板离子有高吸附量和良好特异性识别能力的多离子印迹膜(MIIM)。采用SEM对材料的形貌进行了表征,并以多离子印迹聚合物(MIIP)为对比评价了MIIM的吸附性能。结果表明,MIIM对Zn^(2+)、Co^(2+)、Cr^(3+)和Pb^(2+)的吸附量分别是MIIP的1.71、1.43、1.60和9.03倍,最大吸附量分别为21.32、11.21、12.72和25.97 mg·g^(-1)。在竞争离子(Cu^(2+)、Ni^(2+)、Fe^(2+))存在的情况下具有良好的吸附选择性,MIIM的4种模板离子对Ni^(2+)和Fe^(2+)的特异性因子(SP)值在4.86~8.34之间,对Cu^(2+)的SP值在3.58~3.92之间。同时,MIIM可以多次再生,而不会明显降低吸附能力,在废水处理和样品前处理领域具有很好的应用前景。

稀缺主焦煤高效重介分选工艺在吕家坨矿选煤厂的应用

针对吕家坨矿选煤厂原生产工艺存在的问题,分析了入选原煤煤质特性,采用超宽粒级原煤三产品重介质旋流器选煤工艺、新型煤泥重介质旋流器选煤技术-反分流分选工艺、粗精煤泥两段弧形筛组合脱泥回收技术进行技术改造。改造后工艺系统指标检测结果表明,改造可提高综合精煤产率1.78%,增加税前利润10573.2万元。

城市垃圾焚烧飞灰中氯盐及重金属分离提取技术研究进展

城市垃圾焚烧飞灰具有高氯盐、重金属成分组成复杂等特性,将飞灰中高氯盐及重金属等高价值污染物分离提取并资源化利用不仅可以降低飞灰的危害性,还可以减少天然矿物的开采,具有显著的环境和经济效益.本文根据飞灰中氯盐及重金属分离提取的最新研究报道,结合国内外的工业化应用现状,对各类提取工艺存在的优缺点及发展方向进行综述及展望,以期彻底实现飞灰的无害化处置及资源化利用.当前飞灰中氯盐的分离提取技术已经成功得到应用,但综合处置成本仍明显高于螯合后填埋,有待进一步优化.相比之下,飞灰中重金属的分离提取技术尚处于起步阶段,主要限制因素为回收金属价值难以覆盖其提取成本,并且还面临重金属处理不彻底的问题,仍需继续开展相关技术攻关及政策引导.

湿法磁选对粉煤灰中铁和重金属元素的分布影响研究

对煤粉锅炉粉煤灰(FA1灰)和循环流化床锅炉粉煤灰(FA2灰)采用湿法磁选的工艺达到降低其重金属含量的目的。利用扫描电子显微镜、激光粒度仪和X射线衍射仪表征两种粉煤灰在不同磁感应强度和不同磁选溶液浓度条件下磁选前后高磁性和弱磁性部分的形貌、粒度分布和物相分析,同时测定其铁元素和5种重金属元素(Hg、Pb、As、Cr、Cd)的含量变化,发现磁选后两种粉煤灰铁回收率随着磁感应强度增强而逐渐增加,高磁性组中重金属元素含量与弱磁性组有明显差异。结果表明:在磁感应强度为8000 Gs和磁选溶液浓度为20%(质量分数)时,FA1的铁回收率为71.2%,FA2的铁回收率为47.0%。此时FA1磁选后Pb含量差值为0.2 mg/kg、Cr含量差值为9.2 mg/kg、As含量差值为1.1 mg/kg;FA2磁选后Pb含量差值为18.1 mg/kg、Cr含量差值为25.0 mg/kg、As含量差值为9.1 mg/kg。

高含量重密度组分煤重介质旋流器分选特性研究

为了提高重介质旋流器对高含量重密度组分难选原煤的分选效率,设计了新型重介质旋流器模型装置,建立了颗粒在离心旋转流场中沉降分离数学模型,采用试验与理论分析相结合的方法研究新型重介质旋流器的分选特性,揭示高含量重密度组分难选煤分选特性随工艺参数的变化规律,探索影响新型重介质旋流器流场工作悬浮液动态稳定性的因素及重产物排料输运机制。研究结果表明,新型重介质旋流器分选高含量重密度组分煤时,底流重产物排料能力强、处理量大;离心旋流场中的悬浮液密度梯度分布小、密度相对均匀,底流与溢流密度差值较低,流场中悬浮液稳定性更强;入料的压力与悬浮液动态稳定性、分选精度及重产物排料效率直接相关,随着入料的压力增大,底流、溢流口排出悬浮液密度差值增大,可能偏差E值降低,分选精度提高,重产物排出量升高;当入料的压力为25 kPa时,实际分选密度为1.666 g/cm^(3),可能偏差E值为0.09 g/cm^(3),重产物产率为75.23%。本研究为高含量重密度组分煤的分选提供了新的思路。

新型细粒级加重质矿物气固分选流态化密度分布研究

煤炭分选对提升煤炭品质具有重要作用,气固流化床选煤将流态化技术应用于选煤领域,有助于实现煤炭的干法提质。为解决传统Geldart B类加重质流态化分选密度波动大的难题,提出采用Geldart A类细粒级加重质用于流态化分选的思路。系统研究了新型细粒级加重质气固流态化分选床层密度分布特征,探究了床层密度的稳定性和细粒煤分选效果,分析了床层密度方差和分选效率的变化规律。结果表明,细粒级加重质中的床层密度分布更为均匀,轴向密度差异较低;结合床层膨胀行为研究,建立了细粒级加重质流化床床层密度预测模型,密度波动处于±0.1 g/cm 3时可以有效预测床层密度的分布,解决了分选过程中密度调控的难题。

荷正电膜的制备及研究进展

随着分离体系复杂程度的增加及对膜分离性能要求的提高,荷正电膜分离技术发挥着越来越重要的作用。介绍了荷正电膜的制备方法,综述了荷正电膜在纺织印染废水、镁/锂分离、去除重金属和生物医药等方面的应用进展,探讨了荷正电膜存在的主要问题,展望了未来荷正电膜分离技术的发展方向。随着研究的深入及市场需求的增加,荷正电膜将迎来更大的发展空间,在解决水资源短缺、水环境污染方面发挥更加重要的作用。

汪家寨煤矿选煤厂介耗系统工艺技术改造与应用

针对汪家寨煤矿选煤厂介耗较高的问题,从煤质、磁铁矿粉质量、循环水质量和设备等方面分析产生问题的原因,进而采取介质质量管理、循环水水质管理、技术改造和生产管理等措施,解决关键技术问题,并持续改进,不仅介耗明显降低、重介分选系统运行良好,而且取得了节约成本、提高经济效益的效果。

稠油旋流除砂影响因素

稠油携砂给地面生产设施及外输管道带来严重安全隐患,而稠油的高黏特性造成油砂分离困难。优化旋流器结构,探索旋流器高效除砂的进料条件范围对实现高黏稠油旋流除砂具有重要意义。为此,利用数值模拟方法,研究了不同稠油黏度、含水率和旋流器几何结构下的除砂率和压降。结果表明:油水混合液黏度对砂粒分离效率影响显著,远大于旋流器结构对除砂效果的影响;旋流器结构参数中的入口直径、溢流口直径、锥段长度对旋流场和除砂率影响最显著;控制分流比可减少油相从底流口流出,减少资源浪费,但在高黏低含水率条件下调控分流比才具有效果和意义。该研究结果可为稠油旋流除砂器结构优化和旋流除砂工艺设计提供借鉴。

车钩防脱台对重载机车车辆动力学性能影响分析

车钩设置防脱台是防止车钩垂向分离的有效措施,但防脱台对机车车辆动力学性能影响尚不明确。以国内典型的2万t重载组合列车从控机车和货车为研究对象,建立考虑车钩防脱台的从控机车-货车相互作用分析模型,分析防脱台的作用效果,研究连挂车钩初始高度差、机车电制动力和车间纵向拉钩力对防脱台受力及机车车辆动力学性能的影响,并给出防脱台垂向高度合理取值的建议。结果表明:防脱台能有效避免车钩垂向分离,连挂车钩与防脱台间相互作用对轮轨垂向力影响较小;钩舌连挂面润滑时,当连挂车钩初始高度差大于30 mm,防脱台开始起约束作用,其最大受力随初始高度差的增大略有增大;机车电制动力对防脱台最大受力影响较小,而防脱台最大受力随纵向拉钩力的增大近似线性增大;建议防脱台垂向高度取值范围为100~170 mm。

煤基费托合成含蜡滤渣中重质蜡的萃取分离研究

研究煤基费托合成装置中含蜡滤渣的综合利用,在资源利用、经济效益及环保等方面均具有重要意义。以国能宁煤费托加氢精制一线油为萃取剂,采用萃取-离心分离技术,进行了高效回收煤基费托合成含蜡滤渣中重质蜡的研究。通过控制单一变量法,系统考察了渣剂比、萃取温度、离心机转速、离心温度和离心时间对蜡回收率和油损耗率的影响。实验结果表明:在渣剂比1:5、萃取温度80℃、离心机转速3500 r/min、离心温度80℃、离心时间5 min的条件下,蜡回收率稳定在91%~94%之间,油损耗率稳定在15%~18%之间,具有良好的萃取分离效果和技术经济可行性。

Extraction and separation of Fe(Ⅲ) from heavy metal wastewater using P204 solvent impregnated resin

The extraction and separation of Fe（III） from heavy metal wastewater generated in zinc smelting process were studied using solvent impregnated resin containing CL- P2O4. The influence of pH and temperature on absorbing heavy metal cations by static adsorption was investigated. The batch tests on adsorption equilibrium, kinetics and elution efficiency were carried out to evaluate the performance of CL-P204. Column operations for extraction and separation of Fe（III） by CL-P2O4 were performed for further optimization of process parameters and feasibility evaluation. The reaction mechanism of Fe（III） and CL-P2O4 was analyzed through saturation capability, slope analysis and infrared spectroscopy （IR）. The results show that the separation of Fe（III） from heavy metal wastewater using CL- P2O4 can be achieved through process of adsorption and desorption at a flow rate of 1.53 ml·min^-1·cm^-2, pH 0.8 and temperature of 25℃. The experimental data of Fe（III） adsorption by CL-P2O4 have a satisfactory fit with Langmuir adsorption equation and Freundlich adsorption isotherms. The probable molecular formula of extracted complex is Fe[R2（R2H）], and the adsorption reaction equation is concluded as following： Fe3＋ ＋ 4RH 〈=〉Kex Fe[R2（R2H）] ＋ 3H＋ （Kex, extraction equilibrium constant）. This study will supply the fundamentals for treatment of heavy metal wastewater.