湿法炼锌E.Z.针铁矿法除铁工艺研究北大核心

论述了E.Z.针铁矿除铁的方法,对锌焙烧矿中性浸出-热酸浸出-预中和-E.Z.针铁矿除铁工艺进行研究。试验表明,E.Z.针铁矿除铁工艺较传统两段浸出工艺具有明显的技术优势。     

湿法炼锌E.Z.针铁矿法除铁工艺研究

论述了E.Z.针铁矿除铁的方法,对锌焙烧矿中性浸出-热酸浸出-预中和-E.Z.针铁矿除铁工艺进行研究。试验表明,E.Z.针铁矿除铁工艺较传统两段浸出工艺具有明显的技术优势。     

锌焙砂热酸浸出液还原-中和沉铟的工艺试验研究

针对高铁高铟锌焙砂的热酸浸出液,进行了还原-中和沉铟工艺条件试验研究,确定了最佳工艺条件,其中还原过程:硫化锌精矿过量系数1.3,酸度60 g/L,反应温度90℃,反应时间4 h,还原后液Fe3+浓度小于1.0 g/L;中和沉铟过程:反应pH4.0,反应温度60℃,反应时间30 min,采用该条件,在浸出液中铟含量0.15 mg/L情况下,铁还原率93.81%,中和沉铟率99.80%,渣含铟0.36%。采用还原-中和沉铟工艺,既可有效回收铟,又利于下一步针铁矿沉铁。     

含锌溶液中阴离子对除铁过程影响的热力学规律

本文通过对主体阴离子分别为OH~-、SO_4~-和Cl~-的含锌溶液针铁矿除铁过程的热力学进行计算和分析,详细探讨了不同阴离子对针铁矿沉淀规律的影响。所得结果指出,溶液中引入离子SO_4~(2-)和Cl~-均能增大针铁矿的溶解度;而在相同条件下相同铁含量的锌硫酸盐或锌氯化物溶液中,要获得相同的除铁效果,氯化物体系针铁矿除铁过程更易实现。     

含钒浸出液除铁工艺的探究

对某地石煤物料直接酸浸液中除铁的工艺进行探究,通过选用"中和-还原-溶剂萃取"试验方案,并且通过试验,最终确定了最优的工艺指标参数,使除铁率达到了99%以上,钒回收率达到80以上,有效的解决了浸出液除铁和提高钒收率的目的。     

硫化锌精矿氧压浸出过程中的沉铁机理

硫化锌精矿中的铁在氧压浸出过程浸出进入溶液后,在后续除铁的同时要向溶液中鼓压缩空气,利用其中的氧气将溶液中的亚铁离子氧化成三价铁离子进行针铁矿除铁,而针铁矿除铁系统庞大,生产成本高,尤其高海拔地区空气含氧量低,除铁效果也会大打折扣,从而影响后续工序的正常生产以及锌锭产品的品质。因此,找到硫化锌精矿氧压浸出过程中的沉铁机理,通过控制浸出工艺参数,尽量将铁在浸出过程中沉入渣中,对简化氧压浸出工艺流程具有重大意义。本文通过对硫化锌精矿氧压浸出锌冶炼过程中沉铁机理进行分析,为硫化锌精矿氧压浸出生产操作参数的确定提供参考。     

湿法冶金(包括Zn、Mn、Cu、Ni、Co等)除铁的几种主要方法

论述了湿法冶金除铁的几种主要方法,包括中和水解法、黄钾铁矶法与针铁矿法除铁的化学反应、热力学分析及技术条件等.     

锌冶炼过程中浸渣加压还原酸浸除铁工艺优化

铁是金属锌产品中主要的杂质元素之一,如何去除是目前锌冶炼生产过程亟须解决的技术难题,湿法锌冶炼中如何除铁已开展了很多研究。介绍了工业上常用的几种湿法锌冶炼工艺流程以及常用的除铁方法,分析了黄钾铁矾法、针铁矿法、赤铁矿法和氧压浸出法等除铁方法的工艺特点以及相应的产品指标,并开展了锌中浸渣加压还原酸浸除铁工艺研究。结果表明：在高温高压条件下,可以同时进行浸锌沉铁,使铁以赤铁矿渣的形式沉淀,达到了浸锌除铁的目的,不需单独设计除铁工序,酸浸液中铁可低于4 g/L,酸度40~50 g/L H2SO4,利用沸腾焙烧炉产出的SO2烟气作为还原剂通入高压釜前段将溶液中Fe3+还原为Fe2+, Fe3+还原率高达94%,将O2通入高压釜中段,对锌中浸渣进行加压酸浸,锌还原浸出率可高达90%。该工艺可以有效解决除铁工艺工序长、设备多、投资大、操作复杂等问题,实现了缩短流程、简化设备、方便操作以及高效安全的生产目的。     

针铁矿除铁法在锌氧压浸出工艺生产的应用研究

当今锌氧压浸出工艺已成为锌冶炼的主要趋势,该工艺绿色环保,锌精矿中的硫元素以单质硫的形式回,从根本上解决了火法炼锌产出的二氧化硫等气体对环境的污染,针铁矿除铁工艺是整个锌氧压浸出工艺中关键核心技术之一,针铁矿工艺除铁渣产出量少、有价金属夹带少、过滤效果好等优势,在生成针铁矿同时,能够吸附系统溶液中的Ga、Ge、F、TOC等杂质,达到共脱除的效果。本课题对连续大规模针铁矿除铁法在锌氧压浸出湿法炼锌工艺的应用研究,分析了该工艺的控制要点,探索锌湿法冶炼除铁的发展和方向。     

低浓度钴溶液除铁、钙、镁和P204深度除杂工艺研究

研究了从低浓度钴溶液中除去铁、钙、镁的pH条件和P204萃取除杂工艺.除铁初步试验表明:黄钠铁矾法除铁时,将pH值控制在3.0～4.0之间,除铁效果很好,达到99％以上.在黄钠铁矾-针铁矿联合法的除铁操作条件下,除铁效果也达到了95.65％,且钴损率从21.3％降到了4.74％;低浓度钴溶液最佳除钙镁pH值为3.5～4.0;正交试验得到P204萃取除杂最佳工艺参数:有机相组成ψP204/ψ汽油为25％/75％,O/A相比1∶2,皂化率为75％.     

Behaviour and characterization of hematite process for iron removal in hydrometallurgical production

The separation of zinc and iron is essential in hydrometallurgical processes, especially for treating high-iron sphalerite. The hematite precipitation process for removing iron is an effective way to achieve the high-efficiency separation of zinc and iron. The authors studied the effect of temperature and time on the precipitation behaviour and characterised the precipitation products through X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and chemical analysis. The hematite precipitate contained more than 50% iron, less than 0.5% zinc, 0.1% arsenic and 5% sulfur; more than 95% K, 50% Na and 50%–60% F were co-precipitated, and less than 1% Zn, Mg, Mn and Cl remained in the residue. Because of the uncontrolled supersaturation conditions, jarosite and goethite were generated. Extension of the reaction time and increasing the reaction temperature enabled conversion of most of the goethite and sodium jarosite to hematite during the hematite precipitation process.     

Commercial Applications of the Sherritt Zinc Pressure Leach Process and Iron Disposal

The Sherritt Zinc Pressure Leach Process has been successfully commercialized, in integration with existing roast-leach electrowin plants or replacing all the roasters and establishing direct leach-electrowin process for zinc production from the treatment of a wide variety of zinc bearing feed materials. Currently at four plants, approximately a total of 220 000 tons per year of zinc is being produced through pressure leaching and achieving elimination of about 260 000 tons per year of sulphur dioxide emission to the atmosphere.

The disposal of iron bearing residues has been an integral part of zinc production since the treatment of zinc sulphide concentrates through roast-leach electrowin route started about one hundred years ago. Four iron precipitation processes have been commercialized: the jarosite process; the goethite process; the paragoethite process; and the hematite process. The paper describes the commercial applications of the Sherritt Zinc Pressure Leach Process and its integration with the commercially applied iron precipitation processes.     

EFFECT OF CERTAIN SURFACTANTS ON THE LEACHING AND PRECIPITATION PROCESSES IN ZINC FERRITE RESIDUE TREATMENT

The effect of a surfactant mixture of nonylphenolpolyethylene glycol (D1), dinaphthylmethane-4,4′-disulphonic acid (D2), and polyethylene glycol with molecular weight 400 (D3) on the dissolution of zinc and metal impurities present in zinc ferrite residue in dilute sulfuric acid (160 g L^?1 H₂SO₄) as well as on both jarosite and goethite precipitation was studied at 90°C. The following influences of the surfactant mixture (D1 + D2 + D3), determined by comparing the results obtained in the presence and absence of surfactants, were found. Adsorption of surfactants on zinc ferrite residue surface decreases the dissolution of zinc and metal impurities (Fe, Cu, Cd, As, Sb, and Co). Their extraction efficiencies at the end of the super hot leaching process carried out with surfactants are 4.85–6.29% lower than without them. The formation of a sulfur “sponge” layer on the surface of liquor during the dissolution of ZnS present in zinc ferrite residue is hindered by the surfactants due to their effect as wetting agents and sulfur dispersants. The presence of surfactants reduces the amount of zinc and metal impurities (Fe, Cu, Cd, and As) remaining in the solution after jarosite or goethite precipitation by 5.33–5.86% or 8.03–9.93%, respectively. The volume of jarosite and goethite precipitates increases in the presence of surfactants due to their effect as wetting and flocculation agents. On the other hand, D1 and D3 act as complexing agents. The abovementioned effects of surfactants improve the sorption capacity of both jarosite and goethite, thus ensuring better purification of zinc sulphate solutions, but hindering zinc leaching.     

用针铁矿法从锌焙烧烟尘的热酸浸出液中除铁

研究了从锌焙烧烟尘常压热酸浸出液中沉淀针铁矿的过程。试验结果表明,反应时间和空气流量对除铁率的影响不显著,而反应温度和溶液终点pH是除铁过程的主要影响因素。在终点pH3.0、反应温度333 K、反应时间2 h、空气流量0.2 m3/min的条件下,除铁率超过99.5%,溶液中铁浓度可由40g/L降至0.1 g/L以下。     

Defining the Paragoethite process for iron removal in zinc hydrometallurgy

The previously ambiguous Paragoethite process and residue are defined, and the importance of a fundamental understanding of iron-phase precipitation in hydrometallurgical processing is demonstrated. A review of iron removal in zinc hydrometallurgy and in the Paragoethite process extends previous Paragoethite process studies and provides a brief overview of the iron-phase ferrihydrite, including recent experimental evidence. It is demonstrated that commonly referred to ‘amorphous iron phases’ are likely to be the nanoscale minerals ferrihydrite and/or schwertmannite. In the case of the Paragoethite process, 6-line ferrihydrite constitutes around 40–50% of the residue. Through further characterization and continuous crystallization studies the remaining precipitated components of Paragoethite process residues were found to be solid-solution jarosite phases (containing Pb), silica (containing iron), and at lower pH, poorly crystalline goethite. By using continuous crystallization, the effect of pH on phase formation and on the properties of the residue is documented; emphasizing filterability constraints and the role and reaction of residual calcine. Such studies have permitted a more fundamental understanding of the simultaneous precipitation of ferrihydrite, goethite, and jarosite from acidic hydrometallurgical liquors, including the interplay in this kinetically controlled system, where ferrihydrite is favoured. Reasons for poor filterability are suggested, indicating that the rate of crystallization, and hence, supersaturation, governs phase formation and residue properties. The aggregation-dominated and kinetically favoured nanoscale ferrihydrite particles dictate the physical properties of the residue.     

湿法炼锌除铁工艺研究

介绍了常规法、热酸浸出、氧压浸出、针铁矿和赤铁矿等几种湿法炼锌除铁工艺,重点对SO2还原浸出、热酸还原浸出、氧压还原浸出的赤铁矿除铁工艺的各项指标进行了比较。含铁低的原料,适宜采用常规工艺和针铁矿工艺;含铁高的原料适宜采用黄钾铁矾法和赤铁矿法;而氧压浸出工艺两种原料都能适应。     

Water balance and magnesium control in electrolytic zinc plants using the E.Z. selective zinc precipitation process

There is an increasing tendency for modern electrolytic zinc plants to experience water balance and magnesium control problems because of the simultaneous need to maximize zinc recovery and produce environmentally acceptable leach residues and precipitates. The Selective Zinc Precipitation process developed by the Electrolytic Zinc Company of Australasia involves the precipitation of basic zinc sulfate using limestone. Water balance and magnesium control may be achieved by either discarding the process filtrate, or by using it to wash precipitates in a closed circuit operation. The process filter cake is used as a neutralizing agent in the zinc plant. The process can be operated over a wide range of temperatures and calcined zinc concentrate may be preferred to limestone as a zinc precipitant to minimize the discard of sulfate. This paper is particularly concerned with a quantitative assessment of various modes of integrating the process into modern electrolytic zinc plants.     

针铁矿法从铜钴矿生物浸出液中除铁的研究

采用针铁矿法除去萃铜后的铜钴矿细菌浸出液中的铁,并对除铁时的pH、氧化剂浓度、氧化时间、保温时间等因素进行优化。结果表明,控制氧化过程中pH为4.0、氧化温度70℃、保温时间1h、氧化剂浓度8%,除铁率和钴回收率分别为99.9%和99.5%。针铁矿法除铁可在常压和较低温度(70℃)下进行,而且不需外加其他金属阳离子就能获得过滤性能良好且可作为含铁富矿使用的沉淀渣。     

从高炉瓦斯泥中湿法回收锌的新工艺(Ⅰ):废酸浸出及中和除铁

针对攀钢高炉瓦斯泥含锌高、不能直接返回烧结配料的问题,提出了以该厂自有的钛白废酸作浸出剂,采用低酸浸出—中和除铁—萃取—电积工艺从瓦斯泥中回收金属锌。研究了锌的浸出及浸出液除铁过程。结果表明:在废酸用量855L/t瓦斯泥、常温、液固体积质量比4︰1、反应时间2h条件下,锌平均浸出率为97.94%,铁平均浸出率在6.52%以下。对此浸出液进行中和氧化沉铁,在双氧水用量为理论用量的1.3倍、反应温度为50℃条件下,铁、砷、锑共沉淀而被除去,锌损失率在2.90%左右。     

碳化沉淀法从中和渣浸出除杂液中分离回收锌和镁

基于碳酸锌和碳酸镁溶度积的差异,本文开展了碳化沉淀法分离回收锌、镁的研究,在理论计算的基础上,借助电感耦合等离子体发射光谱仪（ICP-OES）、X射线衍射仪（XRD）等表征手段,考察了碳酸盐种类及用量、温度等因素对锌、镁分离效果的影响规律,查明了中和渣浸出除杂液中锌、镁分离的调控方法。理论计算表明,以碳酸盐作为沉淀剂时,锌优先沉淀,且在镁离子沉淀之前,锌已沉淀完全。实验结果表明,相对Na₂CO₃、NaHCO₃、NH₄HCO₃等碳酸盐,以MgCO₃为沉淀剂进行镁、锌分离的效果更佳。实验所得的较优工艺条件为反应温度90 ℃,碳酸镁过量系数1.20,反应时间90 min,加料速度2.10 g/min。在该条件下,锌沉淀率达99.99%以上,镁沉淀率低于0.10%,实现了镁、锌的有效分离。所得沉锌渣为碱式碳酸锌,纯度较高,可达到工业碱式碳酸锌合格品（HG/T 2523—93）的技术指标。该方法简单易行,锌、镁分离效果好,且锌、镁均可资源化利用。