自然界堆存的不锈钢渣中,铬的存在状态复杂,且由于其中Cr3+向剧毒的Cr6+转化,故此类不锈钢渣存在严重的铬污染风险,其无害化处置必须引起足够重视。研究显示,不锈钢渣中的6价铬主要以CaCrO4形式存在,毒性较大;而通常认为,以3价或0价存在于铬尖晶石、金属态及氧化物中的铬污染风险小;不锈钢渣铬浸出量在酸性环境下略高于中性环境,而在碱性条件下,随pH值增大,铬浸出量大幅增加;通过现有几种含铬不锈钢渣无害化处置技术的优劣对比,认为若实现含铬不锈钢渣的彻底解毒,宜控制其中铬以稳定矿相存在。
In nature, the phase of Cr in stainless steel slag is complicated, and because of Cr3+ converts to highly toxic Cr6+, so the Cr pollution and harmless disposal of such stainless steel slag must be paid sufficient attention. The former results show that highly toxic Cr6+ presents in stainless slag as CaCrO4, ter-valent or zero-valent chromium in chrome-spinel, metallic state and oxides used to usually be considered low pollution risk. Leaching amount of Cr in acid environment is higher than in basic environment but not significant, and in basic condition, the leaching amount of Cr increases with the increase of pH value. Some harmless disposal technologies of chromium-containing stainless steel slag are contrasted. If complete detoxification of chromium-containing stainless steel slag achieved, the Cr in slag should be controlled to stabilize mineral phase.
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