CAJ | 학술논문

运用 XRD、ICP-AES、AFS、TG-DSC 与毒性浸出试验研究了铜火法冶炼中石灰-铁盐法处理酸性废水（污酸）过程中含重金属及砷的污泥（中和渣）形成机理和特性。结果表明：电石渣乳中主要成分Ca(OH)2与污酸中硫酸反应生成CaSO4·xH2O并成为污泥的主要成分；重金属离子主要通过水解反应被沉淀下来，而砷以砷酸盐及亚砷酸盐沉淀而去除，在pH=12.4时电石渣乳与污酸一次中和反应之后，主要有害元素从103～102 mg/L降低至1 mg/L左右，经过絮凝剂添加、浓缩固-液分离与多次空气氧化步骤后使得主要重金属含量达到10?2 mg/L数量级，实现净化后水质达到GB 4913-85污水排放标准；污泥随着温度的升高而逐渐失重，室温至160℃时污泥中自由水与CaSO4·xH2O结晶水依次脱除，温度至400℃左右污泥中砷氧化物升华，至600～800℃范围内少量碳酸钙发生分解，至1050℃以上CaSO4在开始分解为氧化钙并造成明显失重；毒性浸出实验中污泥浸出液中As与Se的浓度明显高于GB 5085.3-2007所允许范围，属于危险废弃物。
운용 XRD、ICP-AES、AFS、TG-DSC 여독성침출시험연구료동화법야련중석회-철염법처리산성폐수（오산）과정중함중금속급신적오니（중화사）형성궤리화특성。결과표명：전석사유중주요성분Ca(OH)2여오산중류산반응생성CaSO4·xH2O병성위오니적주요성분；중금속리자주요통과수해반응피침정하래，이신이신산염급아신산염침정이거제，재pH=12.4시전석사유여오산일차중화반응지후，주요유해원소종103～102 mg/L강저지1 mg/L좌우，경과서응제첨가、농축고-액분리여다차공기양화보취후사득주요중금속함량체도10?2 mg/L수량급，실현정화후수질체도GB 4913-85오수배방표준；오니수착온도적승고이축점실중，실온지160℃시오니중자유수여CaSO4·xH2O결정수의차탈제，온도지400℃좌우오니중신양화물승화，지600～800℃범위내소량탄산개발생분해，지1050℃이상CaSO4재개시분해위양화개병조성명현실중；독성침출실험중오니침출액중As여Se적농도명현고우GB 5085.3-2007소윤허범위，속우위험폐기물。
The formation mechanism and characteristics of sludge(neutralizing slag) containing heavy metals and arsenic from acidic wastewater(waste acid) in copper metallurgy plant were studied by using XRD,ICP-AES,AFS,TG-DSC and toxic leaching tests. The results showed that the main sludge component,CaSO4·xH2O,was formed in the neutralizing reaction between the main carbide slag emulsion component,Ca(OH)2,and waste acid. During the neutralizing reaction,heavy metals deposited in the process of hydrolyzation and arsenic was mainly removed by the formation of arsenate and arsenite. After the neutralizing reaction at pH of 12.4,the concentration of harmful elements decreased from 103-102 mg/L to around 1mg/L. The successive processes including addition of flocculation,solid-liquid separation via concentration and air oxidation further lowered the concentration of the harmful elements to around 10?2 mg/L,lower than national standard(GB 4913- 85). The weight loss of the sludge increased with the increasing of the reaction temperature. Free water and crystal water were sequentially removed in the range of room temperature to 160 ℃;arsenic oxides began to volatilize at the temperature around 400 ℃;when the temperature increased to the range of 600-800 ℃,a small amount of CaCO3 in the sludge decomposed to CaO;at the temperature above 1050 ℃,the main phase of CaSO4 began to decompose to CaO followed by an obvious weight loss. The contents of As and Se in the sludge leaching solution in the toxic leaching experiment were obviously higher than national standards(GB 5085.3-2007),indicating that this sludge was a hazardous waste.