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.

Cooperative effect of sodium lauryl sulfate collector and sodium pyrophosphate depressant on the flotation separation of lead oxide minerals from hematite

As a cornerstone of the national economy,the iron and steel industry generates a significant amount of sintering dust containing both valuable lead resources and deleterious elements.Flotation is a promising technique for lead recovery from sintering dust,but efficient separation from Fe_(2)O_(3) is still challenging.This study investigated the cooperative effect of sodium lauryl sulfate(SLS,C_(12)H_(25)SO_(4)Na)and sodium pyrophosphate(SPP,Na_(4)P_(2)O_(7))on the selective flotation of lead oxide minerals(PbOHCl and PbSO_(4))from hematite(Fe_(2)O_(3)).Optimal flotation conditions were first identified,resulting in high recovery of lead oxide minerals while inhibiting Fe_(2)O_(3) flotation.Zeta potential measurements,Fourier transform infrared spectroscopy(FT-IR)analysis,adsorption capacity analysis,and X-ray photoelectron spectroscopy(XPS)studies offer insights into the adsorption behaviors of the reagents on mineral surfaces,revealing strong adsorption of SLS on PbOHCl and PbSO_(4) surfaces and remarkable adsorption of SPP on Fe_(2)O_(3).The proposed model of reagent adsorption on mineral surfaces illustrates the selective adsorption behavior,highlighting the pivotal role of reagent adsorption in the separation process.These findings contribute to the efficient and environmentally friendly utilization of iron ore sintering dust for lead recovery,paving the way for sustainable resource management in the iron and steel industry.

Separation of arsenic and antimony from dust with high content of arsenic by a selective sulfidation roasting process using sulfur

The separation of arsenic and antimony from dust with high content of arsenic was conducted via a selective sulfidation roasting process.The factors such as roasting temperature,roasting time,sulfur content and nitrogen flow rate were investigated using XRD,EPMA and SEM-EDS.In a certain range,the sulfur addition has an active effect on the arsenic volatilization because the solid solution phase（（Sb,As）2O3）in the dust can be destroyed after the Sb component in it being vulcanized to Sb2S3 and this generated As2O3 continues to volatile.In addition,an amorphization reaction between As2O（3 ）and Sb2O（3 ）is hindered through the sulfidation of Sb2O3,which is also beneficial to increasing arsenic volatilization rate.The results show that volatilization rates of arsenic and antimony reach 95.36%and only 9.07%,respectively,under the optimum condition of roasting temperature of 350℃,roasting time of 90 min,sulfur content of 22%and N2 flow rate of 70 m L/min.In addition,the antimony in the residues can be reclaimed through a reverberatory process.

Separation of arsenic from arsenic-antimony-bearing dust through selective oxidation-sulfidation roasting with CuS

The feasibility of a new method for separating arsenic from arsenic-antimony-bearing dusts using Cu S was put forward,in which Sb was transformed into Sb2O4 and Sb2S3 that stayed in the roasted calcine while As was volatilized in the form of As4O6.The factors such as roasting temperature and Cu S addition amount were studied using XRD,EPMA and SEM-EDS.Cu S has an active effect on the separation of arsenic due to the destruction of(Sb,As)2 O3 structures in the original dust and the simultaneous release of As in the form of As4O6.At a roasting temperature of 400°C and Cu S addition amount of 130%,the volatilization rates of arsenic and antimony reach 97.80 wt.%and 8.29 wt.%,respectively.Further,the high As volatile matter can be used to prepare ferric arsenate after it is oxidized,with this treatment rendering the vapor harmlessness.

A novel hydrothermal method for zinc extraction and separation from zinc ferrite and electric arc furnace dust

A novel hydrothermal process was developed to extract zinc from pure zinc ferrite（ZnFe2O4） nanopowder and zinc-containing electric arc furnace（EAF） dust using hexahydrated ferric chloride（FeCl3-6H2O） as a decomposing agent.The effects of solid FeCl3-6H2O to ZnFe2O4 ratio by mass（RF/Z）,hydrothermal reaction temperature,and time on zinc extraction were systematically investigated.In the results,when the hydrothermal reaction is conducted at 150℃ for 2 h with RF/Z of 15：20,the efficiency of zinc extraction from ZnFe2O4 reaches97.2%,and the concentration of ferric ions（Fe^3＋） in the leaching solution is nearly zero,indicating a high selectivity for zinc.In addition,the zinc extraction efficiency from the EAF dust reaches 94.5%in the case of the hydrothermal reaction performed at 200℃ for 10 h with the solid FeCl3-6H2O to EAF dust ratio by mass（RF/EAF dust） of 15：10.Zinc and iron separation is achieved by adjusting the pH value of the leaching solution according to the different precipitation pH values of metal hydroxides.

Study on the System for Separating Sulfurfrom Flue Gas and Dust

This paper describes the structure of the system for separating sulfur from flue gas and dust. In the paper, the velocities of turbulent flow and laminar flow inside the tower, the total of liquid membrance, and the additional flow of rotation fogged fluid are calculated, and the separation of rotation air-solid affected by tower is analyzed. The velocity distribution in quasi free vortex area is obtained from experiment. The minimum separated particle diameter is computed. The paper also studies the chemical reactions of flue gas containing sulfide with the dynamic fogged sulfur separating agent and discusses the main factors related to the effect of separating sulfur and dust. At last, the applications of separating sulfur in industrial stove and collecting dust in environmental engineering are introduced.

Research on Performance of U Separator in Sand and Dust Test System

Sand/dust test is one of the key projects to examine the environmental adaptability of ordnance equipment.In order to decrease the abrasion of test facility caused by the sand/dust particles,the particles contained in the airflowneed to be reclaimed effectively.Amathematical model of Useparator is established.The flowfield and the trajectories of particles inside the separator are obtained using a numerical simulation method,and the separation efficiency and pressure drop of separator with different rows of separate components are also obtained at various flowvelocities.The simulation results indicate that the efficiency of U inertia separator is affected by the flowvelocity evidently,and a reasonably designed separator can meet the requirement of the separation efficiency in particular situation.The results can be use as reference for the design and test of sand/dust separate systems.

含锌冶金尘泥还原焙烧-磁选分离试验

为实现钢铁企业含锌冶金尘泥低碳环保高效的资源化利用,对铁含量为30.38%、锌含量为4.79%的含锌冶金尘泥进行还原焙烧-磁选分离研究。结果表明,该含锌冶金尘泥直接磁选难以实现锌铁有效分离,在焙烧温度950℃、焙烧时间20 min、磁选强度100 mT等条件下,磁选精矿铁回收率为79.50%、铁含量为57.00%、锌含量为2.45%,磁选尾矿锌回收率为71.06%、锌含量为9.92%、铁含量为16.81%,锌铁分离效果较好。磁选产物中精矿主要以单质Fe为主,尾矿主要由SiO_(2)与ZnO等物相组成。

从铁矾渣侧吹熔炼—烟化法烟灰中回收锌镉及其净化除杂

研究了采用酸性浸出—硫化除杂法从铁矾渣侧吹熔炼—烟化法产出的烟灰中回收锌、镉,并选择性除去浸出液中的铜,产物用以制备镉掺杂硫化锌;在热力学分析基础上,探明了硫酸体系下锌浸出率影响因素及其浸出动力学;通过正交试验明确了各参数对硫化钠选择性除杂的影响。结果表明:烟灰中锌主要以氧化锌形式存在,其浸出过程符合混合控制,表观活化能为73.70 kJ/mol;在最佳条件下,锌浸出率达98.99%。以Na_(2)S用量为理论添加量的3.2倍,控制体系pH=2.0,铜去除率可达95.97%,同时有效保留锌、镉,实现了铜与锌、镉的选择性分离。

铁浴条件下电炉粉尘球团的熔融与分离行为

为了提高对含锌电弧炉粉尘(EAFD)的利用效率,实验研究EAFD球团在铁浴条件下的还原熔化行为。定义铁液滴球形度作为判断其凝聚的标准,然后探讨铁液滴直径和球形度之间随时间变化的关系。根据实验最终建立EAFD颗粒的熔化和分离行为。结果表明,在铁浴条件下,EAFD球团的Zn去除率在5.0 min时达到99%以上,但在15.0 min时金属渣分离还没有完成。由于成分的波动,在EAFD球团中形成几个区域的液态渣,然后液态渣不断增加,直到球团完全熔化。球形度>65%、直径>500μm的Fe液滴的数量随着时间的推移而减少,大直径的Fe液滴先完成分离。渣铁分离过程如下:在布朗运动下Fe液滴在渣中形成,之后Fe液滴直径在马兰戈尼效应下增加,Fe液滴在渣中下降速度符合斯托克斯定律。

环栅式动力除尘器分离性能的数值模拟与实验

【目的】为提高环栅式动力除尘器的分离性能,研究结构参数与工况参数对分离效率和压降的影响,确定最优结构参数和工况参数。【方法】采用数值模拟方法研究结构参数对环栅式动力除尘器分离性能的影响,优化除尘器的结构参数,然后依据优化的结构参数设计除尘器,并搭建分离性能测试实验平台,研究不同工况参数对除尘器的分离效率和压降的影响,确定除尘器的最佳工况参数。【结果】净气流以较高气速通过除尘器后部环缝,颗粒的逃逸发生在最后2级环缝处,最后1级环缝处最高气速为57.88 m/s,一般逃逸颗粒的粒径≤22μm。环栅式动力除尘器优化结构尺寸为:筒体直径为150 mm,环厚度为20 mm,环栅数量为20,前16个环间距为8 mm,后4个环间距为2 mm,环高为5 mm,环错位为1 mm。环栅式动力除尘器优化工况参数为:抽气流量分数为20%,气速为15 m/s。【结论】在最优结构参数和工况参数条件下,环栅式动力除尘器分离效率最高,模拟值更接近实验值。颗粒质量浓度的变化对分离效率影响不大,环栅式动力除尘器适用于分离不同质量浓度的粉尘颗粒。

微波焙烧对钢铁行业含锌冶金尘泥锌铁分离的影响

为推进钢铁行业含锌冶金尘泥的资源化利用,对铁含量为30.38%、锌含量为4.79%的含锌冶金尘泥进行微波还原焙烧-磁选分离试验研究。结果表明:含锌冶金尘泥未焙烧直接磁选以及常规马弗炉还原焙烧-磁选的方式均难以较好实现含锌冶金尘泥中锌铁的有效分离;在微波马弗炉700℃、15 min时,焙烧产物中主要存在的物相为单质Fe,焙烧产物在磁场强度为150 mT时,含锌冶金尘泥中锌铁能够达到较好的分离,所得磁选的精矿指标:锌含量为2.73%、铁含量为57.84%、铁回收率为88.67%,磁选的尾矿指标:铁含量为9.54%、锌含量为9.85%、锌回收率为61.72%。

含铟粉尘的处理工艺现状与展望

含铟粉尘是金属冶炼流程产生的固体废弃物之一,包含锌、钾、铝、铁、铟、铅、镉等金属,是回收稀有金属铟的重要原料。针对现阶段含铟粉尘回收铟过程中存在的分散损失严重、回收率低、处理难度大等问题,本文以含铟粉尘回收铟的全流程处理工艺为主线,对含铟粉尘处理过程中火法预处理、湿法浸出、富集分离等环节的常用技术和工艺进行对比分析,探究不同工艺的独特机理和处理流程,同时讨论不同工艺的特点和局限性,指出现阶段各工序工业生产中存在的问题;重点综述铟湿法浸出和富集分离提取两个环节的技术进展,并基于现阶段工业粉尘“无害化、减量化、资源化”的处理目标与发展趋势,提出未来含铟粉尘综合回收处理的新思路,为实现含铟粉尘中铟等高附加值元素回收利用提供参考。

基于CFD的可燃性粉尘管道非接触式除尘机理研究

为提高非接触式清扫管道机器人在可燃性粉尘管道中的清扫效果,采用流场颗粒力系、力矩平衡理论对干燥和潮湿环境下颗粒滚动和切向移动的分离条件和临界风速进行分析;利用CFD技术对有无管道机器人条件下的粉尘管道壁面风速的变化情况进行仿真分析;结合分离条件和风速仿真结果进行干燥和潮湿环境下壁面粉尘清扫效率的研究。研究结果表明:颗粒分离的临界风速与颗粒直径呈负相关,与液桥颗粒体积比呈正相关;管道机器人的除尘管道壁面风速可增至无管道机器人的2.69~27.84倍,管道机器人可有效提高0.5~4.0 mm直径颗粒的清扫效率。研究结果可为可燃性粉尘管道非接触式安全清扫研究提供理论支持。

基于新型分风控尘方法的综掘工作面控尘机制研究

为改善综掘工作面粉尘污染严重的问题,针对陕西榆林大柳塔煤矿综掘工作面,提出一种安装有分风器的新型分风控尘方法,利用Fluent对使用新型分风控尘方法的粉尘扩散规律进行模拟,分析压风口距工作面不同距离及不同压抽比对粉尘扩散规律变化的影响。结果表明:当压风口距工作面10~20 m时,粉尘积聚、沉降在工作面区域巷道底部,司机处粉尘浓度较低,控尘效果较好;固定压风口距工作面的距离为10 m,压抽比为1.0时,高浓度粉尘积聚在工作面区域,司机处粉尘浓度控制在50 mg/m^(3)以下,控尘效果较好;通过现场实测,粉尘浓度与模拟结果的误差小于15.2%。

锡冶炼烟尘中锡、锌、镉的分离回收工艺研究

研究了采用硫酸浸出—氧化水解脱砷—锌粉置换镉工艺分离回收锡冶炼烟尘中的锡、锌、镉,考察了各因素对分离回收效果的影响。结果表明:在初始硫酸浓度15%、液固体积质量比3∶1、浸出时间120min、浸出温度90℃条件下,Zn、Cd浸出率分别为93.25%、89.35%,Sn浸出率小于0.1%;浸出液在双氧水加入量为2%、控制终点pH为5时,除砷后夜中As质量浓度降至0.1mg/L;除砷后液在反应温度60℃、锌粉用量为理论量1.0倍、搅拌速度250r/min、反应时间30min条件下,可得到含镉95%以上的海绵镉。该工艺可实现锡冶炼烟尘中有价金属高效回收利用。

酒钢复配除尘灰直接还原-磁选试验研究

除尘灰的处理一直是冶金领域的难点问题。为实现除尘灰的资源化利用,减少除尘灰中有害元素对周边生态环境的影响,对酒钢6种除尘灰复配设计,验证火法工艺处理除尘灰的可行性及有害元素脱除效率,并根据直接还原实验结果确定合适的窑渣磁选实验配料。实验结果表明,按照质量百分比复配,高炉布袋灰∶炼钢二次除尘灰∶堆存高炉布袋灰∶混合除尘灰∶高炉重力除尘灰∶炼钢OG泥=28.50∶7.50∶15.50∶6.50∶28.50∶13.50,配碳量30%,焙烧温度1100℃,焙烧时间60 min,焙烧后烧损率为36.62%,锌、钾、钠的脱除率分别为67.86%、75.56%、72.41%,铁品位为30.77%,焙烧物料经过细磨磁选后,得到的铁精粉铁品位为80.84%,铁回收率高达81.44%。多种除尘灰复配后直接还原-磁选回收金属铁的试验及机理分析,有望为除尘灰的处理开拓新途径。

精轧机出口导卫装置上切水板行程提升改造

针对精轧机出口导卫装置上切水板上安装的烟尘抑制装置与上工作辊冷却集水管存在较大干涉问题,采取了改变烟尘抑制装置安装位置及供水管路走向的措施,实施后轧制稳定性得到了提升,实现了降低生产成本的目的。

火法处理钢铁粉尘中有价元素研究现状及展望

针对国内外钢铁冶金粉尘的化学组成和各有价元素的赋存状态,本文比较了国内外提取钢铁冶金粉尘有价元素的工艺现状,并基于热力学基本原理,着重分析了火法处理工艺的影响因素及存在的问题。在此基础上,围绕钢铁冶金粉尘协同资源化问题,提出高效利用粉尘自身所含碳素资源,采用火法富集—湿法分离提取—尾渣资源化工艺是我国冶金行业未来实现钢铁冶金粉尘全量资源化的一条有效途径。

矿用集气尘渣装置在瓦斯抽采钻孔施工中的研制与应用

目前煤矿治理煤层瓦斯的根本途径是通过钻孔进行瓦斯抽采。在钻孔施工过程中,由于现场条件有限和防尘、防喷、防超管理工作不到位,现场工作环境极差,极易发生瓦斯超限事故,严重时会有瓦斯喷出的危险。以施钻为切入点,分别从钻孔孔口密封、气尘渣收集及主动引流、被动缓冲等方面对钻孔施工全过程产生的气、尘、渣提出解决方案,研制了矿用集气尘渣装置,使钻孔施工期间产生的尘渣、瓦斯和喷孔引起的瓦斯超限得到了有效控制,改善了施工环境,确保了煤矿安全生产。