ABSTRACT

With the rising focus on the development of complex refractory ores, one of the major environmental challenges has been in the treatment and processing of arsenic-bearing minerals. An increasingly common approach is to immobilize arsenic as stable ferric arsenate phases during pressure oxidation, utilizing an existing process in the treatment of refractory arsenic-bearing ores. This review examines the lifecycle of the arsenic species in the pressure oxidation stage, from the source of the arsenic-bearing minerals in the feed to the various reaction products following pressure oxidation. The reactions and conditions for the formation of the different products have been detailed, with the oxidation temperature, time, feed iron-to-arsenic ratios, and pH being the main determinants for the characteristics of the arsenic-bearing phases. With an emphasis on arsenic fixation, the factors that contribute toward the formation of stable solid phases such as basic ferric arsenate sulfate and scorodite have also been examined. Subsequently, existing thermodynamic and kinetic models for the behavior of arsenic in pressure oxidation will be discussed. Future opportunities in this area have also been highlighted, including the use of in-situ techniques to probe the system at pressure oxidation conditions, the simulation of arsenic-bearing species, and further investigations on how precipitation is affected by the curing process and the presence of other cations.

摘要

随着对复杂难熔矿石开发的日益关注，主要的环境挑战之一是含砷矿物的处理和加工。一种越来越普遍的方法是在压力氧化过程中将砷固定为稳定的砷酸铁相，利用现有工艺处理难处理的含砷矿石。本综述检查了压力氧化阶段砷物质的生命周期，从进料中含砷矿物的来源到压力氧化后的各种反应产物。已经详细介绍了不同产品形成的反应和条件，其中氧化温度、时间、进料铁砷比和 pH 值是决定含砷相特征的主要因素。以砷固定为重点，还研究了有助于形成稳定固相的因素，例如碱式砷酸硫酸铁和臭葱石。随后，将讨论砷在压力氧化中行为的现有热力学和动力学模型。还强调了这一领域的未来机会，包括使用原位技术在压力氧化条件下探测系统、模拟含砷物质，以及进一步研究沉淀如何受固化过程和存在的影响其他阳离子。将讨论砷在压力氧化中行为的现有热力学和动力学模型。还强调了这一领域的未来机会，包括使用原位技术在压力氧化条件下探测系统、模拟含砷物质，以及进一步研究沉淀如何受固化过程和存在的影响其他阳离子。将讨论砷在压力氧化中行为的现有热力学和动力学模型。还强调了这一领域的未来机会，包括使用原位技术在压力氧化条件下探测系统、模拟含砷物质，以及进一步研究沉淀如何受固化过程和存在的影响其他阳离子。