浙江省不锈钢酸洗行业环境污染控制及资源循环利用研究

发布时间：2018-01-14 19:38

本文关键词：浙江省不锈钢酸洗行业环境污染控制及资源循环利用研究　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文针对浙江省表面处理行业危险废物的来源、性质、管理和处置现状进行分析,对现有的管理措施和处置技术进行评价,提出相应的策略。不锈钢加工是表面处理行业重要的组成部分,浙江省是我国重要的不锈钢生产省份,酸洗废液是危险废物的主要来源。通过深入剖析不锈钢酸洗加工行业存在的环境污染问题,研究危险废物的来源、组成及处置措施,提出行业综合治理工艺方案和建议措施。采用两级吸收还原工艺可满足NOx达标排放,生产酸洗废水收集后采用“二级物化+一级氧化+砂滤”处理组合工艺对废水进行深度处理,然后回用至生产车间,实现水资源的循环利用,同时也满足一级排放要求。采用减压蒸馏发对废酸液进行酸再生回收,实现废酸液的循环再利用,减少后续中和药剂的消耗及危废的产生量。研发环保型酸洗抑雾剂解决酸雾、黄烟等环境问题,NOx和NO浓度瞬时浓度分别降低了 85%和84%,稳定浓度降至40mg/Nm3和18mg/Nm3,而车间浓度降至3mg/Nm3和1mg/Nm3,分别下降了 90%和94%;添加抑雾剂之后,酸洗液表面一直被致密的泡沫层所覆盖,除了减少酸雾的挥发之外,同时也可以减少热量的损失,良好的保温效果可以大大减少蒸汽量,提高酸洗速率。通过进一步开发基于双氧水的Fenton氧化绿色酸洗新工艺,彻底解决酸洗行业NOx超标,废水总氮难以达标、污泥量大等环境难题,通过回收废酸洗液中的金属制备硫酸亚铁副产品,同时实现废酸的循环利用,实现不锈钢行业的健康可持续发展。现场试验表明对常见几种不锈钢的酸洗时间为30～60min,酸洗之后钢材表面洁净且光亮,产品基本能满足相关质量要求,平均得率97.9%。结晶体主要成分为FeSO4·7H20,结晶率大约为61.2%,镍的含量为4.99%,若除去结晶水镍的含量将远远高于5%,达到废物出售回收的要求。此时酸液中的金属浓度为17%,硫酸浓度为28%,该酸液可以直接返回到酸洗槽,通过调节HF浓度后可以继续进行酸洗。
[Abstract]:In this paper, the source, nature, management and disposal status of hazardous waste in surface treatment industry in Zhejiang Province are analyzed, and the existing management measures and disposal technology are evaluated. Stainless steel processing is an important part of surface treatment industry and Zhejiang Province is an important province of stainless steel production in China. Acid pickling waste liquid is the main source of hazardous waste. Through in-depth analysis of environmental pollution problems in stainless steel pickling processing industry, the source, composition and disposal measures of hazardous waste are studied. The comprehensive treatment process scheme and suggestion measures are put forward. Adopting two-stage absorption reduction process can meet the discharge standard of NOx. After the pickling wastewater was collected, the wastewater was treated with the combined process of "secondary physicochemical primary oxidation sand filter", and then reused to the production workshop to realize the recycling of water resources. At the same time, it also meets the requirement of the first class discharge. The waste acid is recycled by vacuum distillation to realize the recycling of the waste acid. To reduce the consumption of subsequent neutralization chemicals and the production of hazardous waste. The instantaneous concentration of no _ x and no _ x decreased by 85% and 84% respectively to solve the environmental problems such as acid mist and yellow smoke. The steady concentration decreased to 40 mg / Nm3 and 18 mg / Nm3, while the workshop concentration decreased to 3 mg / Nm3 and 1 mg / Nm3, which decreased by 90% and 94, respectively. After adding the anti-fogging agent, the surface of the acid lotion has been covered by a dense foam layer. Besides reducing the volatilization of the acid mist, it can also reduce the loss of heat, and the good heat preservation effect can greatly reduce the amount of steam. Through the further development of Fenton oxidation green pickling process based on hydrogen peroxide, the environmental problems such as NOx exceeding the standard, the total nitrogen of wastewater is difficult to reach the standard, and the amount of sludge is large are solved thoroughly. Ferrous sulfate by-product was prepared by recovering metal from waste acid washing liquid, and recycling of waste acid was realized at the same time. The field test shows that the pickling time of several common stainless steels is 30 ~ 60 min, and the steel surface is clean and bright after pickling. The average yield of the product is 97.99.The main component of the crystal is FeSO4 路7H20, the crystallization rate is about 61.2, and the content of nickel is 4.99%. If the content of nickel crystal is much higher than that of 5%, it can reach the requirement of waste sale and recovery. At this time, the concentration of metal in the acid solution is 17, and the concentration of sulfuric acid is 28. The acid can be directly returned to the pickling tank. Acid pickling can be continued by adjusting HF concentration.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X757;TG174.4

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