Wang Xingrun, Zhang Fengsong, Nong Zexi
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China ; School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China.
ScientificWorldJournal. 2014 Mar 2;2014:260504. doi: 10.1155/2014/260504. eCollection 2014.
To investigate the effect of sintering temperature and sintering time on arsenic volatility and arsenic leaching in the sinter, we carried out experimental works and studied the structural changes of mineral phases and microstructure observation of the sinter at different sintering temperatures. Raw materials were shaped under the pressure of 10 MPa and sintered at 1000~1350°C for 45 min with air flow rate of 2000 mL/min. The results showed that different sintering temperatures and different sintering times had little impact on the volatilization of arsenic, and the arsenic fixed rate remained above 90%; however, both factors greatly influenced the leaching concentration of arsenic. Considering the product's environmental safety, the best sintering temperature was 1200°C and the best sintering time was 45 min. When sintering temperature was lower than 1000°C, FeAsS was oxidized into calcium, aluminum, and iron arsenide, mainly Ca3(AsO4)2 and AlAsO4, and the arsenic leaching was high. When it increased to 1200°C, arsenic was surrounded by a glass matrix and became chemically bonded inside the matrix, which lead to significantly lower arsenic leaching.
为研究烧结温度和烧结时间对烧结矿中砷挥发及砷浸出的影响，我们开展了实验工作，并研究了不同烧结温度下烧结矿的矿物相结构变化和微观结构观察。原料在10 MPa压力下成型，于1000~1350°C烧结45分钟，空气流速为2000 mL/min。结果表明，不同的烧结温度和不同的烧结时间对砷的挥发影响较小，砷固定率保持在90%以上；然而，这两个因素对砷的浸出浓度影响很大。考虑到产品的环境安全性，最佳烧结温度为1200°C，最佳烧结时间为45分钟。当烧结温度低于1000°C时，FeAsS被氧化为钙、铝和铁的砷化物，主要是Ca3(AsO4)2和AlAsO4，砷浸出率较高。当温度升至1200°C时，砷被玻璃基体包围并在基体内发生化学键合，这导致砷浸出率显著降低。
