TREATMENT OF WASTE PICKLING LIQUORS: PROCESS SYNTHESIS AND ECONOMIC ANALYSIS

An economic analysis was carried out for three different recycle/recovery options for waste pickling liquors from hydrochloric acid pickling baths in an existing small-mid scale plant presently neutralizing and discarding waste pickling liquors. The analysis was based on process synthesis and design, which were completed by using real plant data along with some experimental work. Three basic schemes were studied: the addition of metallic iron to convert unused hydrochloric acid to ferrous chloride recovery by evaporation and recycling of a large proportion of the unused acid, and removal of ferrous chloride by crystallization to enable the recycling of the unused acid. All three schemes were evaluated at the same concentration of ferrous chloride by-product, which can be directly sold or converted later to ferric chloride, which has a higher market value. Extrapolation of existing solubility data was verified experimentally, cost estimation was done for purchased equipment and utility requirement, and feasibility analyses of the process schemes were completed. Depending on the market demand for the by-product and the criteria chosen, metallic iron addition or evaporation found to be recommendable, while the relatively more expensive crystallization process was also found to bring improvement over the no-treatment alternative.     

KINETICS AND MECHANISM OF THE OXYPRECIPITATION OF WASTE HYDROCHLORIC PICKLING LIQUORS

The aim of the research project presented in this paper is to devise a process to treat waste liquors from the pickling of iron or steel with hydrochloric acid in rolling mills, recovering the high iron content in the form of oxides or oxyhydroxides which can later be used in other industrial processes. In addition to reducing water pollution, such a process attaches a new value to this ferrous waste.

Chlorinated liquors are oxyprecipitated, leading to the formation of different combinations of iron oxides and oxyhydroxides, with the total removal of Fe⁺² and the production of ammonium chloride solutions easily broken down into hydrochloric acid and ammonia. The precipitates have different industrial outlets, making the oxyprecipitation process an attractive solution for the treatment of waste pickling liquors.     

盐酸法钛白粉新工艺副产氯化亚铁制备四氧化三铁

探索了一种以盐酸法钛白粉新工艺副产氯化亚铁为原料制备四氧化三铁磁粉的放大试验工艺,把副产危废氯化亚铁制备成用途广泛的四氧化三铁磁粉,实现资源的综合利用。研究结果表明：选用氧化钙为沉淀剂与氯化亚铁反应得到氢氧化亚铁,在分散剂辅助作用下通入空气使氢氧化亚铁被氧化成三价氢氧化铁,控制氧化钙及分散剂加料时间间隔为1.5 h、氧化温度为80℃、氧化时间为8.5 h,将氢氧化铁与氢氧化亚铁以物质的量比为2∶1均匀混合,通过正压分离得到固体,控制分离前pH为6.5,最后通过烘干、研磨等后处理得到四氧化三铁磁粉。进行50 kg级别放大试验得到四氧化三铁产品,收率达到97%。该工艺将副产危废转化为有一定经济效益的产品,进一步完善了盐酸法钛白粉新工艺。     

钢材盐酸酸洗废液的回收与利用研究进展

介绍了钢材酸洗废液的主要来源,组成和危害,按钢材盐酸酸洗废液的回收方法的不同,简要介绍了目前钢材盐酸酸洗废液的回收和利用的研究进展。     

稀盐酸回收氯化氢工艺技术分析

介绍了从有机氯产品生产中副产的稀盐酸中回收氯化氢的工艺方法,并对主要的工艺参数、公用工程消耗和主要设备的选型进行了研究。     

钛白粉厂硫酸亚铁资源综合利用实验研究

钛白粉生产过程中硫酸亚铁是其主要的副产品,硫酸亚铁的产生量大,回收利用率低成了制约钛白粉生产的"瓶颈"。文章目的通过采用投加一定量的氯化钙然后调节pH来回收铁的方法对钛白粉生产过程中的副产品硫酸亚铁进行综合利用的实验分析。通过研究发现:氯化钙与硫酸亚铁反应过程中在一定的搅拌强度反应一段时间后,氯化钙的最佳投加量为Ca2+与SO42-的摩尔比1.3;氢氧化钙的最佳投加量OH-与Fe2+物质的量之比2.4,能够将硫酸亚铁中的铁全部转化成氢氧化铁,其中氯化钙溶液在整个系统中循环利用。     

SOME FACTORS INFLUENCING THE RATE OF PICKLING OF SHEET IRON1

Experiments with regard to various factors entering into pickling of sheet iron show that: (1) a freshly made sulphuric acid pickling bath pickles faster than a bath in which there is any concentration of ferrous sulphate and that (2) there is no evident advantage in adding a portion of old pickling solution to a new pickling solution “to get it to work right,” although prictical experience indicates otherwise; (3) increased ferrous chloride concentration in a muriatic acid pickling bath increases the rate of pickling; (4) ferric sulphate in a sulphuric acid bath will accelerate the rate of pickling, but will soon change to ferrous sulphate and then retard the rate; (5) decrease in acidity from usual strength decreases rate of pickling; (6) increase of temperature of bath accelerates rate of pickling; (7) iron annealed just previous to pickling loses 250–4000 more in pickling than unannealed iron; (8) use of monel metal basket accelerates the rate of pickling due to electrochemical reactions; and (9) use of muriatic acid or sodium chloride in mixtures with sulphuric acid retards the rate of pickling.     

盐酸酸洗废液蒸馏回收稀盐酸工艺参数研究

以稀盐酸回收浓度为指标,采用蒸馏法处理热浸镀锌企业盐酸酸洗废液,通过间歇蒸馏正交实验、简易精馏实验,对蒸馏压强、酸度、含铁量、蒸馏时间等参数进行系统研究,可为热浸镀锌钢企盐酸酸洗废液资源化工艺设计提供技术依据。     

粉煤灰酸法提取氧化铝蒸发母液回收氯化铝工艺研究

在粉煤灰盐酸法提取氧化铝蒸发结晶工序中,由于氯化铝溶液多次循环蒸发,引起蒸发母液中钙、镁、硅、磷等杂质离子的富集,当母液中杂质离子的浓度达到一定程度时需将部分氯化铝蒸发母液外排,这将会造成15%~20%原料铝的损失。利用氯化氢气体盐析结晶技术对蒸发母液进行处理,通过两级盐析结晶和浓盐酸洗涤,不仅实现了回收蒸发母液中氯化铝的目的,还提高了六水氯化铝晶体的纯度,使回收的氧化铝纯度达到99.38%,同时氧化铝中氧化钙、氧化镁、五氧化二磷的质量分数分别降低至2.680×10^-5、2.849×10^-4、2.051×10^-4。提出了蒸发母液回收氯化铝工艺路线,此流程可完全并入现有粉煤灰盐酸法提取氧化铝工艺的主流程。     

氯化锌-甲醇废液的综合利用研究

一种处理三氟氯乙烯工业副产物氯化锌－－甲醇废液的方法，废液中加入稀盐酸溶解后，先精馏分离出甲醇，然后用化学方法除去铁和重金属杂质，得到精制氯化锌溶液，将精制氯化锌溶液蒸发浓缩可得无水氯化锌，进一步将氯化锌溶液转化为氧化锌。     

盐酸法生产饲料级磷酸氢钙联产碳酸钙及氯化铵

传统盐酸法生产饲料级磷酸氢钙工艺存在许多弊端，介绍了盐酸法制备饲料级磷酸氢钙副产碳酸钙及氯化铵新工艺。该工艺所用生产装置既可大量消化副产盐酸，又可在生产饲料级磷酸氢钙的同时联产碳酸钙和氯化铵产品，消除了氯化钙废液外排。     

新疆地区PVC行业汞污染防治措施

分析了PVC生产中汞污染来源和产生途径,阐述了新疆PVC生产企业含汞废水治理现状并提出了含汞废水治理措施,介绍了盐酸脱析技术及蒸发结晶技术在含汞废水处理上的应用情况。     

盐酸浸出钛石膏实验研究

钛石膏是钛白粉生产过程中利用石灰中和钛白废酸而形成的一种工业固体废弃物。同时由于钛石膏含有多种有价金属元素,也是重要的二次资源,必须加以回收利用。利用盐酸浸出钛石膏,回收有价金属元素,实现钛石膏的综合利用。研究了盐酸浓度、浸出温度、浸出时间以及液固质量比等因素对浸出效果的影响。实验结果表明,在盐酸质量分数为15%、浸出时间为60 min、浸出温度为90 ℃、液固质量比为6∶1时,金属铁的浸出率>90%。该处理工艺流程简单,处理成本低,为钛石膏的利用提供一种新途径。     

盐酸酸解硫化钡黑灰制备硫化钠和氯化钡工艺的研究

介绍盐酸酸解硫化钡黑灰(重晶石和煤还原煅烧的产物)的工艺,利用氯碱厂的副产盐酸与硫化钡反应制得硫化钠,再用液碱吸收酸解时产生的硫化氢制得氯化钡,还可制得低铁硫化钠。     

碳酸锶渣中锶的盐酸-氯化铵浸取工艺研究

随着电子、有色金属、航空航天等行业的快速发展,锶及锶盐的市场需求越来越大。以碳还原法生产碳酸锶的含锶工业废渣为原料,以盐酸-氯化铵为浸取剂,探究了浸取时间、浸取温度、盐酸-氯化铵物质的量比对废渣中锶浸取率的影响。在单因素实验的基础上,采用3因素3水平的Box-BehnKen响应面分析法对锶浸取工艺做了优化,确定了浸取锶的最优工艺条件。结果表明：在盐酸与氯化铵物质的量比为4.32、浸取时间为104 min、浸取温度为33 ℃的最优工艺条件下,经过4次重复性实验,所得的锶浸取率平均值为95.15%,标准偏差为0.146 2,相对标准偏差为0.153 7%,与预测值相对误差仅为0.17%,所选因素对锶浸取率影响由大到小顺序：浸取时间、盐酸-氯化铵物质的量比、浸取温度,以期为锶渣中锶资源的回收利用提供参考。     

废铅蓄电池铅膏湿法回收制取氯化铅技术的研究

研究了一种由废铅蓄电池铅膏湿法制取氯化铅的工艺技术。采用HCl-NaCl混合溶液将铅膏中的铅浸出制备氯化铅，考查了冷析滤液的处理方法及循环使用效果。结果表明：采用该工艺技术，铅浸出率达99．3％以上，冷析滤液循环使用4次，铅回收率达到98．2％，制取的氯化铅产品纯度达到了试剂化学纯的要求。     

盐酸法钛白扮生产工艺

盐酸法钛白粉生产工艺主要包括酸解、还原、结晶、萃取、水解、煅烧、破碎及盐酸回收等。该生产工艺具有原料适应性强、能耗低、“三废”排放量少、盐酸可循环利用等优点。氯碱企业利用副产盐酸生产钛白粉,可产生较好的经济效益和社会效益,是值得氯碱企业开发的项目。     

太阳能级多晶硅切割废料的酸洗除杂研究

为获得一种制备高纯硅的高纯原料,在分析太阳能级多晶硅切割废料(CLW)物性的基础上,详细研究了CLW的酸浸除杂,超声酸浸除杂,考察了盐酸浓度、酸浸时间、酸浸温度、酸浸液固比和搅拌对除杂效果的影响,并分析了超声酸洗过程动力学,得到的最适宜工艺条件为:w(盐酸)为19％,反应时间3 h,水浴温度为60aC,浸出液固比4:1...     

自酸洗废液制磁性铁泥的氧化共沉淀工艺研究

采用氧化共沉淀方法处理总铁质量分数为3.0%~15.0%的酸洗废液,制备可用作炼铁原料的高含铁 磁性铁泥。以磁性铁泥中干基铁含量为评价指标,研究了中和温度、氧化稀释比、氧化温度、氧化pH、氧化铁比 ［n（铁3+）/n（铁2+）］、氧化气速、脱水合成pH、脱水合成稀释比、脱水合成温度等主要影响因素,得出最佳工艺条件。在中和温度为45 ℃、氧化稀释比为10.0、氧化温度为45 ℃、氧化pH为8.0、氧化铁比为1.7、氧化气速为1.2 L/min、脱水合成pH为8.0、脱水合成稀释比为10.0、脱水合成温度为107 ℃条件下,可制得铁质量分数为57.4%的磁性铁泥。该方法实用价值高,具有较好的经济和社会效益。     

THE THEORY OF PICKLING OF SHEET IRON AND STEEL FOR ENAMELING PURPOSES1

The fundamental principal of efficient pickling is that efficient pickling does not depend on the solution of a large amount of metal but on the solution of a very thin layer of metal directly beneath the scale, rapidly and with copious evolution of hydrogen. The activity of an acid solution depends on the amount of acid present, the fraction of the acid that is ionized, and on the speed with which the ions move. Since the electrical conductivity of an acid solution is a measure of both the hydrogen-ion concentration and the speed at which the ions move, the electrical conductivities of a series of acid solutions indicate the relative activities of the various solutions. The most effective concentrations of acid lie between 15 and 20%. Heating acid solutions reduces their viscosity and renders the particles more mobile, thus increasing the activity of the solutions. Sulphuric acid is cheaper in first coat than hydrochloric acid, but the latter acts more rapidly and the pickling is completed with less solution of iron. Additions of small amounts of common salt (sodium chloride) have a marked effect on increasing the rate of pickling of sulphuric acid baths. This is due to the formation of a corresponding amount of hydrochloric acid. The chief action of addition agents is to reduce the amount of acid vapor in the fumes from pickling vats and thus permit the use of highly efficient concentrations of acid (between 15 and 20%). Hydrogen absorbed by metals during pickling may be largely removed by immersing the metal in boiling hot water for a few minutes.