(1. 昆明理工大學(xué) 省部共建復(fù)雜有色金屬資源清潔利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，昆明 650093；
2. 昆明理工大學(xué) 冶金與能源工程學(xué)院，昆明 650093)
摘 要: 鋼渣是一種冶金工業(yè)固體廢棄物，具有強(qiáng)堿性并富含鐵氧化物，對(duì)酸性重金屬?gòu)U水處置有著巨大潛力，改性鋼渣有望進(jìn)一步提高除砷效率并應(yīng)用于污酸除砷。實(shí)驗(yàn)研究了酸、堿、鹽和熱改性對(duì)鋼渣理化性質(zhì)和除砷效率的影響，考察了強(qiáng)化氧化對(duì)改性鋼渣除砷性能的影響規(guī)律，分析了除砷后鋼渣浸出毒性特性。結(jié)果表明：與未改性鋼渣相比，改性鋼渣除砷性能有所提高，其中酸改性和鹽改性鋼渣的除砷性能顯著提高。針對(duì)含砷濃度為4200 mg/L的污酸，按照固液比0.04 kg/L加入酸改性鋼渣，在氧化劑作用下并在室溫振蕩反應(yīng)120 min，處置后污酸殘余砷濃度降至88.44 mg/L，砷去除效率達(dá)到97.89%，除砷后鋼渣浸出毒性低于危險(xiǎn)廢棄物鑒別標(biāo)準(zhǔn)《GB 5085.3— 2007》限值5 mg/L，屬于一般固體廢棄物，可安全堆存。研究表明：酸改性鋼渣能釋放大量Ca、Fe離子，通過(guò)共沉淀和吸附的作用可將砷去除。鋼渣預(yù)處理及除砷機(jī)制為鋼渣兩步法處置含砷污酸提供了一種思路。
關(guān)鍵字: 污酸；砷；改性鋼渣；共沉淀；吸附
（1. State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, China;
2. Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:Steel slag, a bulk solid waste in metallurgical industry, characterizes with high alkalinity and iron-laden composition. It shows the great potential for the heavy metal wastewater treatment, expecting to be used for the high-efficiency arsenic removal from waste acid after further modification. The effects of modifications including acid, alkali, salt, and thermal pretreatments on the physicochemical properties and arsenic removal efficiency were studied. The influence of oxidation on the arsenic removal performance of modified steel slag was investigated. The toxic characteristics of arsenic-laden steel slag obtained from arsenic removal were analyzed. The results show that the modified steel slag exhibits better arsenic removal performance compared to untreated one, of which the arsenic removal performances of acid and salt modified steel slag are significantly improved. For the waste acid with arsenic concentration of 4200 mg/L, the acid-modified steel slag is added to remove arsenic according to the solid-liquid ratio of 0.04 kg/L and the reaction is kept at room temperature for 120 min. After the reaction, the residual arsenic concentration in the waste acid decreases to 88.44 mg/L, following with an arsenic removal rate of 97.89%. In addition, the arsenic leaching concentration of arsenic-laden steel slag obtained from arsenic removal is lower than the limit value of the hazardous waste identification standard (GB 5085.3—2007) 5 mg/L, which belongs to general solid waste and can be safely stored. It is found that the acid-modified steel slag can release a large amount of Ca and Fe ions that enable to remove arsenic by coprecipitation and adsorption. The arsenic removal mechanism using modified steel slag provides a feasible solution for the arsenic-containing waste acid treatment using a stepwise process composed of pretreatment of steel slag and arsenic removal.
Key words: waste acid; arsenic; modified steel slag; coprecipitation; adsorption
