【作者】 卢世柱；

【导师】 钟善锦；

【作者基本信息】 广西大学 ， 城市生态学， 2011， 硕士

【摘要】 随着国家环境保护要求越来越严格,减排力度不断加大,对低浓度二氧化硫的治理要求更加紧迫,不符合国家环保政策的企业将很快被停产、淘汰。鉴于广西华锡集团股份有限公司来宾冶炼厂受减排目标的强制要求,本次研究依托来宾冶炼厂的清洁生产审核工作,结合广西环保厅科技标准处提出的“广西有色冶炼低浓度二氧化硫烟气治理现状调研与对策研究”课题和来宾市“十一五”非电力行业烟气二氧化硫治理重点项目,以来宾冶炼厂锡系统为主要研究对象,采取氧化锌法进行低浓度二氧化硫治理试验研究。广西有色冶炼低浓度二氧化硫烟气治理现状调研结果表明,全区锌锡冶炼企业排放的二氧化硫浓度普遍不高,平均仅为0.2%,不能直接用于制酸,目前主要采取间接制酸法和湿法烟气转化脱硫法进行治理。同时调研也发现这些企业存在以下问题：(1)冶炼工艺落后,低浓度二氧化硫治理范围不大；(2)制酸法治理效果好,但尾吸脱硫装置安装及运行不正常；(3)烟气脱硫法运行成本高,副产品难以综合利用；(4)企业环保管理不到位,清洁生产重视不足。与其它脱硫方法相比,氧化锌法具有吸收效率高、吸收剂来源充足、循环利用度高、节省投资和运行费用等明显优势,而广泛应用在铅锌冶炼企业的低浓度二氧化硫治理实践中。从前人的研究成果中,不难发现,影响气液接触状况的二氧化硫入口浓度、浆液固含量、液气比、空塔气速等参数以及浆液酸度是影响氧化锌脱硫效率的主要因素。因此,本次试验是通过改变烟气二氧化硫入口浓度、浆液pH值、浆液固含量、液气比、空塔气速等工艺条件,探索工艺条件改变对脱硫效率的影响,寻求合理可行的处理参数。试验以来宾冶炼厂锌系统产生的氧化锌烟尘作为吸收剂,采用氧化锌法处理锡系统产生的低浓度二氧化硫烟气,锡系统低浓度二氧化硫主要产生于粗炼车间的沸腾炉、反射炉、烟化炉。本次试验是工业性试验,即在2009年11月开始进行,历时半年时间完成单因素试验和综合试验。单因素试验结果表明：(1)二氧化硫入口浓度在小于13650mg/m3的范围内,脱硫效率随着浓度的增加而变大,当浓度达到13650mg/m3时,脱硫效率达到最大值,然后随着浓度的增加,脱硫效率反而下降。(2)在酸性条件下,脱硫效率随着浆液pH值的增加而增大,近似为线性关系,但增加到一定程度(pH=5)后,脱硫效率增大不是很明显。(3)浆液固含量在大于12%的范围内,脱硫效率是随着它的增加而相应提高。(4)脱硫效率随液气比增加而增大,但液气比达到4.5%之后,脱硫效率不再显著增大。(5)在空塔气速小于5.43m/s的范围内,脱硫效率随着气速增加而变小；在大于5.43m/s的范围内,脱硫效率与空塔气速呈正相关。综合试验结果表明,在二氧化硫入口浓度为13000mg/m3,氧化锌浆液pH=5左右,浆液固含量为14.3%,液气比为4%,空塔气速为4.8m/s工艺条件下,脱硫效果最佳,吸收效率高达95.1%。本次研究为锌锡冶炼企业低浓度二氧化硫治理工程设计、运营提供了科学依据,对类似企业完成持续减排目标具有重要意义。但由于受到研究时间、研究成本和企业条件的限制,本次研究还存在以下不足之处：试验不能对空塔气速-脱硫效率曲线做出明确的解释,需要进一步深入研究。更多还原

【Abstract】 With stricter policies on environmental protection and strengthening method dealing with water conservation and pollution control, low-SO2 disposal is becoming an urgent task around the country, and enterprises operating beyond the boundary of environmental protection policies are facing shutdown. By request of Laibin smelting plant of Guangxi Huaxi Group Corporation L.T.d, taking tin(Sn) system in Laibin smelting plant as research target, the author conducted an experimental research on low-SO2 disposal with zinc oxide(Sno) basing on the reviewing work of clean production and combining the research project of "Investigation and strategy research on the current disposal situation of low-SO2 gas of Guangxi non-ferrous smelting", proposed by Scientific Standard Office of Guangxi Environmental Protection Department and the "the Eleventh Five-year Plan"of "Key project of low-SO2 gas disposal in non-electric industry" by Laibin municipality.Result of current investigation on low-SO2 gas disposal in Guangxi non-ferrous smelting showed that the concentration ratio of SO2 discharged by zinc and Tin is generally low, only 0.2% on average. Therefore, it can not be used to make acid directly, and indirect acid making method and desulfurization approach by hydrome smelting gas conversion is widely adopted at present. Meanwhile, investigation and research conducted on these enterprises revealed a series of problems:(1) backward smelting technology, and narrow scope of low-SO2 disposal;(2) though acid making disposal approach achieved desirable result, mis- installation and malfunction exists in end gas absorption desulfurization devices; (3) the cost of gas desulfurization approach is very high, and its byproducts are difficult to be comprehensively utilized;(4) inadequate attention was attached to environmental protection management and clean production of the enterprise. Compare with other desulfurization approaches, zinc oxide approach boasts the following advantages:high absorbility, sufficient source of absorbent, high rate of recycling use, cost-saving and operating expenses- saving. All these advantages make it widely applied into the practice of disposing low-S02 in lead zinc smelting enterprises. Research findings of predecessors showed that the parameters of SO2 inlet which affects gas and liquid contacting condition, the solid content of slurry, liquid to gas ratio, superficial gas velocity, and the degree of acidity are the main elements which affect the ZnO desulfurization efficiency.Therefore, this experiment aims at exploring how technological conditions affect the desulfurization efficiency and seeking for reasonable and practical desulfurization disposal parameters by changing the concentration of inlet SO2, the PH value of slurry, solid content in slurry, liquid to gas ratio, surface gas velocity. Taking the zno dusts produced from Zn system of Laibin smelter as the absorbent, the experiment started from November 2009 and completed half year later by accomplishing mono factorial experiment and comprehensive experiment by using ZnO to dispose the low-SO2 gas produced by the Sn system. Low-SO2 in Zn system mainly came from the furnace in fluid bed, the reverberatory furnace and the fuming furnace in the crude smelting workshop.Result of monofactorial experiment showed:(1) when the concentration of inlet SO2 is smaller than 13650mg/m3, the desulfurization efficiency rose with the increasing of concentration of inlet SO2, when the concentration of inlet SO2 arrived at13650mg/m3,the desulfurization efficiency reached its maximum value, then the desulfurization efficiency began to decline with the continuing increasing of concentration of inlet SO2;(2)Under the acidic condition, the desulfurization efficiency increased with the increasing value of the concentration of inlet SO2, they approached the linear relation, however, when the desulfurization efficiency arrived at a certain level (PH=5), the increasing rate was not obvious any more; (3) when the slurry solid content rate was bigger than 12%, the desulfurization efficiency increased correspondingly with the increasing in slurry solid content rate; (4) the desulfurization efficiency increased with the increasing of liquid to gas ratio, but when the liquid to gas ratio arrived at 4.5%, there was no obvious increasing in desulfurization efficiency; (5) when surface gas velocity was smaller than 5.43m/s, the desulfurization efficiency declined with the increasing of the surface gas velocity, when surface gas velocity was bigger than 5.43m/s,they appeared to be direct ratio relationship.Comprehensive experiment result showed that desulfurization efficiency achieved the best result of up to 95.1% under the conditions of concentration of inlet SO2 arriving at 13000mg/m3,the PH value of Zno slurry of 5,the slurry solid content of 14.3%, liquid to gas ratio of 4%, and surface gas velocity of4.8m/s.These research findings provide scientific evidence for IOW-SO2 disposal engineering design and operation in znsn smelting enterprises and were of great significance for enterprises to achieve sustainable mitigation goal. Due to the limitation of time, research cost and the current conditions of the enterprises, weaknesses still exist:the experiment could not yield definite explanations for curvilinearity between surface gas velocity and the desulfurization efficiency, further study is needed in this aspect in the future.更多还原