【摘要】：隨著經(jīng)濟(jì)的發(fā)展,我國(guó)對(duì)鋼鐵的需求量日益增高,企業(yè)在生產(chǎn)過(guò)程中多采用硫酸酸洗工藝,因此每年產(chǎn)生的酸洗廢液也逐年上升。目前我國(guó)大部分中、小型鋼鐵企業(yè)由于廢酸處理成本較高,未經(jīng)有效處理就將有害酸洗廢液直接排放,不僅污染環(huán)境,還導(dǎo)致水資源的浪費(fèi)。論文以西安某冷拔材廠的硫酸酸洗廢液為研究對(duì)象,通過(guò)正交試驗(yàn)優(yōu)化酸液中和工藝流程,并針對(duì)中和產(chǎn)品中硫酸鈣含量較高的特點(diǎn),對(duì)其直接應(yīng)用于建筑材料及利用水熱法制備硫酸鈣晶須進(jìn)行了可行性研究。在此基礎(chǔ)上,取得了以下成果:通過(guò)酸洗廢液的中和-沉降試驗(yàn),確定最佳處理工藝條件為:工業(yè)生石灰用量為3.20g/L,攪拌速率為450r/min,中和時(shí)間為5min,非離子型聚丙烯酰胺用量為85ppm,沉降時(shí)間為8min,在此條件下中和料漿能快速實(shí)現(xiàn)固液分離,可得到pH值為6.90的澄清中和溶液。利用石灰中和-絮凝沉淀工藝對(duì)西安某冷拔材廠生產(chǎn)的酸洗廢液進(jìn)行了中和處置工程應(yīng)用,處理效果較好,處理后的廢水可作為廠區(qū)回水重復(fù)利用。中和渣制備硫酸鈣晶須試驗(yàn)結(jié)果表明,以中和渣和工業(yè)生石膏為原料,采用水熱法工藝,最佳工藝條件為:原料中石膏和中和渣的質(zhì)量配比為19:1,料漿濃度為5%,料漿pH值為4,水熱反應(yīng)時(shí)間為30min,反應(yīng)溫度為140℃,攪拌速率為180r/min,可以制備出形態(tài)良好的半水硫酸鈣晶須,實(shí)現(xiàn)了對(duì)固體廢物-中和渣的高附加值利用。通過(guò)摻加適量中和渣對(duì)復(fù)合脫硫建筑石膏性能的影響試驗(yàn),確定最佳煅燒制度為:煅燒溫度180℃,煅燒時(shí)間45min,煅燒中和渣的摻量為8%,該條件下制得建筑石膏可達(dá)GB9776-2008 2.0級(jí)要求。通過(guò)控制煅燒時(shí)間、溫度和中和渣的摻量,可利用中和渣制備建筑石膏粉。通過(guò)摻加適量中和渣制備石膏砌塊試驗(yàn)研究,確定中和渣制備石膏砌塊的最優(yōu)條件為:原料的配合比為石膏:水泥:中和渣:礦渣=77:10:8:5,聚羧酸減水劑摻量為1.0%,檸檬酸緩凝劑摻量為0.08%,晶須摻量為3%,在此條件下制備石膏砌塊的7d抗折強(qiáng)度和抗壓強(qiáng)度分別為3.85MPa和13.91MPa,28d抗壓強(qiáng)度高達(dá)31.51MPa。研究對(duì)鋼廠酸洗廢液的無(wú)害化處理和回收利用具有重要的實(shí)用價(jià)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，

本文編號(hào)：2391929