氧浸渣搭配处理锌浸出渣的冶炼方法

介绍了氧浸渣搭配处理锌浸出渣的冶炼方法,由于日益严格的环保要求,对湿法锌冶炼产出的锌浸出渣要求零堆存,目前传统的锌浸出渣火法处理方法存在能耗大,生产成本高,低浓度SO2烟气处理难度大的问题,而采用氧浸渣搭配处理锌浸出渣工艺,以硫代焦或煤,可大大降低能耗,减小生产成本,同时可以产出含硫烟气直接进二转二吸制酸。     

氧压浸出硫回收粗硫池设计计算

硫化锌精矿加压浸出全湿法炼锌工艺是硫化锌精矿不需焙烧脱硫直接浸出工艺。在浸出过程中,大部分硫转化为元素硫进入浸出渣中,浸出渣经处理分离出硫磺,避免了SO_2气体及尾气有可能泄漏对大气的污染。从加压浸出渣中回收元素硫是一个物理过程,其原理是利用元素硫在约120℃时熔化成液态的特点,达到与浸出渣中其它杂质分离。本文对硫回收工艺中粗硫池设计计算进行阐述。     

非氰提金技术研究进展

随着难处理金矿的占比不断增加以及人们对环保问题的日益重视,氰化法受到了技术和环保两方面的制约,非氰方法成为金、银提取的必然趋势。非氰方法包括湿法工艺和火法工艺两大类。系统介绍了湿法非氰方法中卤素法、硫脲法、硫代硫酸盐法、硫氰酸盐法和环保提金剂的原理及发展状况;火法非氰方法主要介绍了具代表性的高温氯化焙烧工艺和造锍捕金工艺,其适用对象分别为铁含量高的含金物料和含砷、硫、碳等难处理金精矿。通过综合分析得出贵金属提取的重要趋势是火法—湿法工艺结合,即先通过火法充分富集贵金属,再利用湿法工艺高效回收。     

影响硫代硫酸盐堆浸回收金溶液的化学性质因素

硫代硫酸盐是一种可采用的贵金属浸出剂。使用氰化物环保问题与难处理金矿石的金回收相关问题一直推动着硫代硫酸盐浸出技术的研究和发展。美国内华达州Newmont矿山已成功地开发出生物氧化与硫代硫酸盐联合堆浸工艺处理碳质高硫化物矿石，硫代硫酸盐直接堆浸工艺处理碳质低硫化物矿石。     

复杂矿石及精矿湿法冶金工艺的进展

由于矿山和冶金工业致力于开发用传统选矿及火法冶金工艺难以处理的矿石,因此,复杂矿石及精矿的湿法冶金处理工艺变得越来越重要。选矿常常面临无法或难以将有价矿物分选为可外销精矿的挑战。湿法冶金利用选择性浸出工艺,常常可以化学分选此类难选矿石。火法处理贱金属精矿投资大,且面临日益严格的环保限制。湿法冶金工艺对于相同的金属产率,通常投资更低,而且避免了与火法冶金相关的烟尘问题,副产品回收的可能性也随着采用湿法冶金处理工艺而提高。以复杂矿石及精矿处理新技术的研发案例作为实例,详细介绍了回收混合硫化矿精矿中铜、钴、铂、钯及金的PLATSOLTM工艺。     

制酸预处理系统在硫回收及净化杂质领域的应用

焦化厂的以氨为碱源焦炉煤气HPF或者PDS湿法脱硫过程中残留或者产生的悬浮硫、副盐、焦油尘及机械杂质等去除,是通过熔硫、离心机分离、脱硫外排及副盐提取等工艺过程进行部分去除维持在一定的范围之内,而且提取后的产物及副产物依然带来诸多有害物质,主流处理工艺流程是回送到原料煤中,到焦炉中进行循环处理,其后的含硫元素物质又会高温裂解回到焦炉煤气中,形成恶性的循环过程。文章根据现有焦化工艺技术发展,利用焦炉煤气脱硫废液及硫泡沫制硫酸预处理技术需要,从而完全替代传统的焦炉煤气湿法脱硫工艺过程中的提硫、提盐和外排脱硫废液等危害转移过程。从而为焦化环保领域开创了一新的思路。     

钙处理对20CrMo齿轮钢硫化物夹杂的影响

在热力学计算的基础上,分析了20CrMo含硫齿轮钢钙处理的工艺条件,并对某厂钙处理后的含硫齿轮钢轧材进行了取样研究。结果表明,RH破空后钙处理的钢水中,硫化物和钙铝酸盐能结合生成复合纺锤状和低熔点夹杂;同时,钙处理前钢中w(O)控制在10×10-6以下,可使加入的钙充分对Al2O3、硫化物进行变性,并有利于形成以MnS为核心的氧硫复合夹杂;而且钢水铝脱氧后调整钢中w(AlS)=0.015%～0.025%,并在温度较高时喂Si-Ca线,可减少凝固过程中硫的偏析。该厂通过钙处理工艺生产的含硫齿轮钢夹杂物形貌良好,各项性能均达到客户的要求。     

热回收型冷冻机在厂房净化空调系统中的应用

1热回收型冷冻机的构造特点 热回收型冷水机组是使用二个冷凝器,利用从压缩机排出的高温气态制冷剂必然去低温处的原理,提高标准冷凝器的水温,促使高温气态制冷剂流向热回收冷凝器,将热量散给热回收冷凝器的水流中。通过控制标准冷凝器的冷却水温度或冷却塔回水流量,可以调节热回收量的大小。离心式冷水机组热回收系统,不仅提供正常温度的冷冻水,还可以提供高温热水,用于空调水或风的预热、工业用水加热等,既环保,又节能,在对有温、湿度要求的净化空调系统中使用非常方便。     

含硫钢冶炼工艺的研究与应用

针对传统含硫钢冶炼工艺存在的问题,介绍含硫钢生产的难点。通过研究电炉出钢复合脱氧剂块加精炼促进剂合成渣洗技术、低硫容量炉渣的研究、硫合金化工艺的研究与开发、钙处理技术优化、开发VD炉梯形吹氩控制技术、软吹工艺控制等工艺技术优化,形成一套成熟的含硫钢冶炼控制新技术,提高钢水洁净度,获得钢水良好的可浇性。VD真空处理后硫损失控制不超过0.005%,实现含硫钢的批量稳定生产,产品质量稳定,满足高端客户的需求。     

HTRI在硫磺回收尾气焚烧炉热工计算中的应用

尾气焚烧炉是硫磺回收装置重要性仅次于酸性气燃烧炉的重要设备,由于H2S的毒性远比SO_2严重,大多数国家的法律规定,含硫尾气未经焚烧不允许排放,因而无论硫磺回收是否设有尾气处理系统,尾气排放前均应通过焚烧将尾气中的H_2S和其它硫化物全部氧化成SO_2后排放。尾气焚烧炉的热工计算大多在硫磺回收装置设计时由SULSIM软件进行计算,目前尚未见采用其它软件进行尾气焚烧炉热工计算的报道。通过HTRI进行尾气焚烧炉的燃烧计算和热平衡计算,计算得到的燃料气量、所需空气量、烟气量较好的符合尾气焚烧炉原设计数据为硫磺回收尾气焚烧炉设计提供了借鉴。     

自蓄热式烧嘴的试验研究

高温低氧燃烧(HTAC)技术是20世纪90年代在燃烧领域中得到广泛重视的一项新技术,该技术具有高效节能和低污染物排放的特性。实现该技术工业应用的两个基本手段是：回收高温烟气余热;创造燃烧区低氧浓度。介绍了自蓄热式烧嘴系统的设计与研制过程。并利用该装置系统地进行了实验室的试验研究,研究结果表明：该装置系统既能高效回收烟气余热,又能大幅度降低NOx的排放,而且其结构简单、实用,具有很好的工业应用前景。     

高温空气资源的开发与应用

高风温无焰燃烧具有高效节能,低ＮＯｘ污染,缩小装置尺寸等优点,高温空气气化能处理低热值燃料,并产生较高热值燃气。此新型燃烧和气化技术的关键是高温空气的生成。经济紧凑,可极限回收余热的蜂窝式陶瓷瓷热体的成功开发,大幅度地降低了高温空气的生产成本,促进了此新型燃烧和气化的发展。分析高温空气,高风温无焰燃烧,高温空气气化的原理和关键技术,为开发高温空气资源,推广新型燃烧和气化技术创造条件。     

回转窖尾气氧化锌脱硫技术及其应用

某冶炼厂采用回转窑回收锌氧压浸出液针铁矿除铁产出铁渣中的氧化锌,原来采用传统的钙法脱硫工艺处理回转窑烟气,存在脱硫效果差、排放尾气不达标、石膏渣难处置、开工率低等问题.经多方考证后,决定改用氧化锌脱硫工艺进行处理,脱硫剂采用自产氧化锌烟尘或焙砂,产出的二氧化硫返回制酸系统,酸解液返电锌系统,不产生二次固体废物.新系统投...     

气淬渣粒飞行动力学模拟试验研究

气淬粒化钢渣工艺是一种全新的干法处理钢渣工艺,此工艺既可以干法处理钢渣又可以对液态钢渣的显热进行高效回收.同时,通过对气淬粒化工艺过程进行有效控制可为钢渣制备高附加值产品奠定基础.采用不同孔型的拉瓦尔喷嘴喷吹不同粒径石英砂,冷态模拟液态钢渣气淬粒化过程中渣粒的飞行轨迹,通过正交实验方法研究不同条件下渣粒落地距离和落地宽...     

Biologically produced sulphide for purification of process streams,effluent treatment and recovery of metals in the metal and mining industry

One of the best available technologies for the removal of metals from water is in the form of metal sulphides. Metal removal by sulphide precipitation is a well-known process that is characterised by compact residues and very high removal efficiencies. Compared to neutralisation alone the sludge volume is 6 to 10 times lower and the toxic metals are removed to a 0.01–1 ppm level. Furthermore, selective metal precipitation is possible, allowing for separate recovery of valuable metals like copper, nickel, cobalt and zinc from nuisance metals like arsenic and antimony. However, the cost of reagent (NaHS or H₂S gas) and safety aspects are often prohibitive.This paper describes a novel biological process for safe and cost effective production of sulphide from elemental sulphur, waste sulphuric acid or sulphate present in effluents. With this technology, gaseous or dissolved H₂S is produced on-site and on-demand in an engineered, high rate bioreactor.Experience with industrial applications at metal processing plants will be presented. The technology can serve to selectively recover metals from e.g. bleed streams, leach liquor, effluent streams and acid mine drainage. Lower overall costs and increased safety (no transport or storage of sulphide, production on-demand and at ambient pressure) are the main advantages of this new process compared to its alternatives.     

Desulphurisation of high sulphur coal to improve industrial utilisation

Abstract

Coal from northeastern India is considered to be a very good quality coking coal owing to its low ash content (<8%). It has an excellent caking property, and after carbonisation it can provide a very good CSR (coke strength, after reaction with CO₂). On the other hand, its metallurgical application is not so encouraging as a result of its high sulphur content (3-7%). Normally the acceptable sulphur content in metallurgical coke is 0·7% maximum. About 90% of the sulphur is present in organic form, and the remaining 10% as pyrites and sulphates. Removal of sulphur from the organic types is somewhat complicated as it cannot be done by any physical process such as benificiation or flotation, whereas sulphur in pyrites and sulphates can be removed by physical means. With a view to lowering the sulphur content of the coal, desulphurisation studies were carried out at elevated temperatures ranging from 400 to 950°C under the flow of various reducing gases such as coke oven gas, water gas, steam and pure hydrogen. The retention time at each temperature of experimentation was usually varied at 15, 30 and 45 min. It was observed that the sulphur content in the coal was decreased in every experiment with the various reducing gases. The extent of sulphur removal in treatment of the coal with coke oven gas was up to 78·1%, that with steam 83·1% and that with water gas 85·7%. The minimum sulphur content found in desulphurised coal was 0·86%, which could not be used for metallurgical purposes unblended. In the case of experiments with steam, a severe loss of carbon (15-20%) was observed because of reaction with the steam, whereas no such losses were observed in experiments with the other two reducing gases. Hydrogen lowered the sulphur content at a faster rate in comparison with the other gases, but could not increase the degree of reduction. The present study may help to establish the technoeconomic feasibility of the processes; however, large scale experimental studies are required for confirmation. I&S/1721     

Thermodynamic and kinetic aspects of the desulphurisation reaction in secondary metallurgy

The desulphurisation of liquid steels with a refining ladle top slag is one of the most important processes of secondary metallurgy. But the process control is even now based on empirical rules. Deviations from the sulphur contents aimed at can often be observed in practice. An improvement of the process control supported by knowledge of the thermodynamics and kinetics of the desulphurisation reaction is of great importance, especially for the production of steels with very low sulphur contents. To investigate the removal of sulphur, operational trials were carried out in 185 t steel ladles. In the trials the stirring gas flow rate, the pressure on the bath surface and the steel composition were varied as process parameters. The obtained results show that ladle slags saturated with lime have a high sulphide capacity. The desulphurisation rate of steel melts increases if the specific stirring energy is enhanced by increasing the gas flow rate or reducing the pressure on the bath surface. In the case of production of Al/Si‐killed steel melts, a desulphurisation degree above 90 % can be obtained by a vacuum treatment within 10 minutes.     

高强焊瓶钢HP345的研制与生产

介绍了首钢迁钢公司通过应用微量钒钛复合微合金化和控轧控冷技术研制与生产高强度HP345焊接气瓶用热轧带钢的过程。分析了批量生产的高强焊瓶钢HP345的化学成分、冶金质量和力学性能。结果表明：对0.17%C-0.25%Si-1.40%Mn成分体系的低碳锰钢进行钒钛复合微合金化（wv≤0.025%、wTi≤0.025%）,可以开发生产出符合国家标准和用户需求的低屈强比高强HP345钢。轧制时可以采用较高的终轧温度和卷取温度。复合添加的微量V、Ti元素对HP345钢的显微组织影响很小,没有明显的细晶强化作用,但有足够数量的析出相颗粒,从而产生明显的沉淀强化作用。     

Dechlorination of ferric chloride with oxygen

Because of increasing ecological concern, the Bureau of Mines is investigating the use of chlorination technology in extractive metallurgy. A key problem is the fact that ferric chloride is commonly generated during processing of a wide variety of ores and minerals. This paper describes small laboratory-scale studies designed to effect dechlorination of ferric chloride by oxygen in a fluidized bed reactor to produce a viable, nonpolluting iron oxide product and chlorine gas, which could be recycled in a chlorination process. These studies demonstrated that close to 100 pct conversions of ferric chloride to ferric oxide and chlorine can be effected by reaction with oxygen at temperatures ranging from 500° to 650°C. The off-gas from the single-stage reactor contained up to 95 pct chlorine. The study also demonstrated that the presence of a small amount of NaCl in the reactor catalyzed the reaction between ferric chloride and oxygen and permitted high conversions at temperatures as low as 500°C.     

Sulphide Capacities of CaO‐SiO2‐Al2O3‐MgO Slags

In Japanese steelworks, hot metal is now being produced by a scrap melting process. With this process, removals of sulphur is very much handicapped because of very high sulphur levels (0.04‐ to 0.09‐ pct by weight) and relatively low tapping temperatures (1623 to 1723 K). In order to overcome such handicaps, the authors explored on the respective phase diagrams. These explorations revealed that {CaO‐SiO₂‐Al₂O₃‐MgO} slags with Al₂O₃ contents of 30‐ to 35‐pct by weight would be good candidates as reagents for sulphur removal from high sulphur hot metal at relatively low temperatures. For better understanding of the thermodynamic properties of the candidate slags, in this study, sulphide capacities were determined through gas/slag equilibrium technique. The experimental results suggest that there would be, at least, a “window” to remove sulphur from high sulphur hot metal as relatively low temperatures.