2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 1: D'Abreu Intl. Symp. / Iron and Steel Making
| Editors: | Kongoli F, Noldin JH, Takano C, Lins F, Gomez Marroquin MC, Contrucci M |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 320 pages |
| ISBN: | 978-1-987820-37-9 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
CD shopping page
A novel method of arsenic encapsulation from high-arsenic contaminated acid by the formation of scorodite
Xing Zhu1; ZHU Xing2;1FACULTY OF METALLURGICAL AND ENERGY ENGINEERING, KUNMING UNIVERSITY OF SCIENCE AND TECHNOLOGY STATE KEY LABORATORY OF COMPLEX NONFERROUS METAL RESOURCES CLEAN UTILIZATION, Kunming, China; 2FACULTY OF METALLURGICAL AND ENERGY ENGINEERING, KUNMING UNIVERSITY OF SCIENCE AND TECHNOLOGY STATE KEY LABORATORY OF COMPLEX NONFERROUS METAL RESOURCES CLEAN UTILIZATION, Kunming 650093, China;
Type of Paper: Regular
Id Paper: 286
Topic: 2
Abstract:
A high-arsenic contaminated acid derived from arsenical antimony fahlore(3Cu2S•As2S3) and enargite(Cu3AsS4) smelt process is one of the biggest hazardous wastes in nonferrous metallurgy (Cu, Ni, Pb, Zn, Sn, et al.) industry in China. Analysis of some enterprises discharge sewage acid arsenic content up to 5~10g/L in general, special circumstances as high as 20g/L, also high-arsenic contaminated acid had other harmful impurities. Limestone neutralization treatment for acid in an acidic nitrate medium pH(0~1)and elevated temperature(55~75¡æ)is described. Under the pH(0~1) arsenic still exists in the solution. Through the analysis XRD¡¢XRF of calcium sulfate, we found that the prepared samples have uniform crystallinity and fine crystalline, hadn¡¯t any other impurity. Then, the arsenic in the leaching solution can be further precipitated as a form of scorodite crystalline (FeAsO4•2H2O). In the precipitating arsenic reaction, in which ferrous ions were oxidized by air gas, the effects of acidity (pH), reaction temperature, air flow rate, the initial concentration of arsenic and the initial molar ratio of Fe(II) to As(V) on arsenic precipitation were investigated. The pH 1.0−5.0, Fe/As molar ratio of 1~1.5, the temperature of 50−90¡æ, and the air flow rate higher than 120L/h, under the test of precipitation, optimal parameter display more than 88% of arsenic could be precipitated as a form of scorodite crystalline.