(中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 砷作為有色金屬礦物的共伴生元素，在有色金屬冶煉過(guò)程中以含砷“三廢”形式大量產(chǎn)出。由于砷具有強(qiáng)致癌性及毒性，導(dǎo)致砷的安全處置問(wèn)題嚴(yán)重困擾著有色金屬冶煉企業(yè)。本文通過(guò)闡述含砷廢水中砷的兩種穩(wěn)定化工藝的研究進(jìn)展，對(duì)比了現(xiàn)有穩(wěn)定化工藝的優(yōu)缺點(diǎn)，結(jié)合藥劑穩(wěn)定化和礦物穩(wěn)定化的優(yōu)點(diǎn)，借鑒砷元素在地球化學(xué)中的成礦規(guī)律，提出了硫化沉砷-水熱還原礦化穩(wěn)定砷的技術(shù)思路。首先采用硫化法脫除含砷廢水中的砷，砷的沉淀率高達(dá)99.65%，硫化沉淀物在TCLP毒性檢測(cè)中砷的濃度達(dá)到212.9 mg/L。然后采用As-S系一元水熱還原礦化法和As-Fe-S系二元水熱還原礦化方法穩(wěn)定砷，穩(wěn)定化產(chǎn)物分別為雌黃和雌黃-鐵硫系(黃鐵礦、硫化亞鐵)混合物，在TCLP毒性檢測(cè)中砷的浸出濃度分別為3.86 mg/L和2.65 mg/L。水熱還原礦化工藝實(shí)現(xiàn)了含砷廢水中砷的脫除及穩(wěn)定化的目的，為水溶液中砷的脫除和穩(wěn)定化提供了新的思路。
關(guān)鍵字: 砷；三硫化二砷；穩(wěn)定化；水熱；礦化
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:Arsenic is one of paragenetic and associated elements in non-ferrous minerals, which is enriched in “the three wastes” containing arsenic during the smelting of nonferrous metal processes. The safety disposal of wastewater containing arsenic has troubled nonferrous metals smelting enterprises due to the strong carcinogenicity and toxicity of arsenic. This paper firstly introduced the sources and harm of wastewater arsenic-containing. And then the stabilization technologies including chemical stabilization and mineral stabilization were reviewed. By comparing the advantages and disadvantages of stabilization technologies for treating wastewater containing arsenic, and referring to the mineralization rule of arsenic in geochemistry, a sulfidization-hydrothermal reduction mineralization process of arsenic was proposed. The results show that, firstly, 99.65% arsenic in wastewater containing arsenic was precipitated in the form of amorphous As2S3 by using Na2S. Then the leachate concentration of arsenic of amorphous As2S3 in TCLP test is 212.97 mg/L. Next, the hydrothermal reduction mineralization process in As-S unary system and hydrothermal reduction mineralization process in As-Fe-S binary system are adopted to transform amorphous As2S3 to orpiment and orpiment and iron-sulfur system (pyrite, ferrous sulfide) mixture separately. And the As leachate concentration of these corresponding hydrothermal slags in the TCLP test is reduced to 3.86 mg/L, 2.65 mg/L separately. A satisfied result of removal and stabilization of arsenic from wastewater are achieved by the novel processes, which provides a promising way to remove and stabilize arsenic from high arsenic containing wastewater.
Key words: arsenic; arsenic trisulfide; stabilization; hydrothermal; mineralization
