金属酸洗废液中和处置和综合利用研究
发布时间：2018-12-26 09:57
【摘要】：随着经济的发展,我国对钢铁的需求量日益增高,企业在生产过程中多采用硫酸酸洗工艺,因此每年产生的酸洗废液也逐年上升。目前我国大部分中、小型钢铁企业由于废酸处理成本较高,未经有效处理就将有害酸洗废液直接排放,不仅污染环境,还导致水资源的浪费。论文以西安某冷拔材厂的硫酸酸洗废液为研究对象,通过正交试验优化酸液中和工艺流程,并针对中和产品中硫酸钙含量较高的特点,对其直接应用于建筑材料及利用水热法制备硫酸钙晶须进行了可行性研究。在此基础上,取得了以下成果:通过酸洗废液的中和-沉降试验,确定最佳处理工艺条件为:工业生石灰用量为3.20g/L,搅拌速率为450r/min,中和时间为5min,非离子型聚丙烯酰胺用量为85ppm,沉降时间为8min,在此条件下中和料浆能快速实现固液分离,可得到pH值为6.90的澄清中和溶液。利用石灰中和-絮凝沉淀工艺对西安某冷拔材厂生产的酸洗废液进行了中和处置工程应用,处理效果较好,处理后的废水可作为厂区回水重复利用。中和渣制备硫酸钙晶须试验结果表明,以中和渣和工业生石膏为原料,采用水热法工艺,最佳工艺条件为:原料中石膏和中和渣的质量配比为19:1,料浆浓度为5%,料浆pH值为4,水热反应时间为30min,反应温度为140℃,搅拌速率为180r/min,可以制备出形态良好的半水硫酸钙晶须,实现了对固体废物-中和渣的高附加值利用。通过掺加适量中和渣对复合脱硫建筑石膏性能的影响试验,确定最佳煅烧制度为:煅烧温度180℃,煅烧时间45min,煅烧中和渣的掺量为8%,该条件下制得建筑石膏可达GB9776-2008 2.0级要求。通过控制煅烧时间、温度和中和渣的掺量,可利用中和渣制备建筑石膏粉。通过掺加适量中和渣制备石膏砌块试验研究,确定中和渣制备石膏砌块的最优条件为:原料的配合比为石膏:水泥:中和渣:矿渣=77:10:8:5,聚羧酸减水剂掺量为1.0%,柠檬酸缓凝剂掺量为0.08%,晶须掺量为3%,在此条件下制备石膏砌块的7d抗折强度和抗压强度分别为3.85MPa和13.91MPa,28d抗压强度高达31.51MPa。研究对钢厂酸洗废液的无害化处理和回收利用具有重要的实用价值。
[Abstract]:With the development of economy, the demand for iron and steel in our country is increasing day by day. The sulphuric acid pickling process is often used in the production process, so the acid pickling waste liquor produced every year is also increasing year by year. At present, because of the high cost of waste acid treatment in most of China's small iron and steel enterprises, harmful acid pickling waste liquid will be discharged directly without effective treatment, which not only pollutes the environment, but also leads to the waste of water resources. In this paper, the acid pickling waste liquor of a cold drawing mill in Xi'an is taken as the research object. The neutralization process of acid solution is optimized by orthogonal test, and the characteristics of high calcium sulfate content in neutralization products are pointed out. The feasibility of its direct application in building materials and the preparation of calcium sulfate whiskers by hydrothermal method was studied. On this basis, the following results have been achieved: through neutralization and sedimentation experiments of acid pickling waste liquor, the optimum treatment conditions are determined as follows: the dosage of industrial quicklime is 3.20g / L, the stirring rate is 450 r / min, and the neutralization time is 5 min. The amount of Nonionic polyacrylamide is 85 ppm and the settling time is 8 min. Under this condition, the solid liquid separation can be realized quickly by neutralizing slurry, and the clarification and neutralization solution with pH value of 6.90 can be obtained. The acid pickling waste liquor produced by a cold drawing mill in Xi'an was neutralized and disposed by lime neutralization-flocculation sedimentation process. The treatment effect was good and the treated wastewater could be reused as backwater in the plant area. The experimental results of preparing calcium sulfate whisker from neutralized slag and industrial gypsum show that the optimum technological conditions are as follows: the mass ratio of gypsum and neutralized slag is 19: 1, and the slurry concentration is 5. PH value of slurry is 4, hydrothermal reaction time is 30 min, reaction temperature is 140 鈩，
本文编号：2391929
[Abstract]:With the development of economy, the demand for iron and steel in our country is increasing day by day. The sulphuric acid pickling process is often used in the production process, so the acid pickling waste liquor produced every year is also increasing year by year. At present, because of the high cost of waste acid treatment in most of China's small iron and steel enterprises, harmful acid pickling waste liquid will be discharged directly without effective treatment, which not only pollutes the environment, but also leads to the waste of water resources. In this paper, the acid pickling waste liquor of a cold drawing mill in Xi'an is taken as the research object. The neutralization process of acid solution is optimized by orthogonal test, and the characteristics of high calcium sulfate content in neutralization products are pointed out. The feasibility of its direct application in building materials and the preparation of calcium sulfate whiskers by hydrothermal method was studied. On this basis, the following results have been achieved: through neutralization and sedimentation experiments of acid pickling waste liquor, the optimum treatment conditions are determined as follows: the dosage of industrial quicklime is 3.20g / L, the stirring rate is 450 r / min, and the neutralization time is 5 min. The amount of Nonionic polyacrylamide is 85 ppm and the settling time is 8 min. Under this condition, the solid liquid separation can be realized quickly by neutralizing slurry, and the clarification and neutralization solution with pH value of 6.90 can be obtained. The acid pickling waste liquor produced by a cold drawing mill in Xi'an was neutralized and disposed by lime neutralization-flocculation sedimentation process. The treatment effect was good and the treated wastewater could be reused as backwater in the plant area. The experimental results of preparing calcium sulfate whisker from neutralized slag and industrial gypsum show that the optimum technological conditions are as follows: the mass ratio of gypsum and neutralized slag is 19: 1, and the slurry concentration is 5. PH value of slurry is 4, hydrothermal reaction time is 30 min, reaction temperature is 140 鈩，
本文编号：2391929
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