The Toowong Process for treatment of complex ores

摘要

Increasing contamination/impurity levels (including arsenic, antimony, mercury etc.) of concentrates is an issue of global commercial and health / environmental significance. With increasing environmental pressures at smelters, penalties for contaminants in concentrates continue to rise, accompanied by lower reject limits. There is a strong incentive for miners to investigate alternative means to remove contaminants in order to increase the value of complex ores and concentrates. This paper discusses the global problem of contamination in complex ores and concentrates, how the Toowong Process technology is a potential solution to this problem, and the opportunities this technology brings to the business of dealing with deleterious elements. In 2017 the global mine production of copper reached 20.0 Mtpa, and production is expected to increase to 25.9 Mtpa by 2020 based on continued demand growth (ICSG, 2017). The majority of this copper is produced via the concentrate-smelting-refining route, with almost 60% of global concentrates being shipped from remote mining operations to Asia for smelting and refining (ICSG, 2017). Arsenic is a common penalty element that is associated with copper concentrates, and based on a world concentrate output grading 0.2% Arsenic (Smale, 2017), over 68,000 tpa of arsenic is also shipped with these concentrates into heavily populated regions in China, Japan, India and Korea. The market for arsenic based products does not meet this supply, which has resulted in the stockpiling of arsenic bearing materials for several decades. Arsenic is a known human carcinogen, as little as 100 - 300 mg arsenic can be a lethal dose to humans (Ratnaike, 2003), and the practice of stockpiling imported arsenic cannot be accepted as a sustainable long-term solution.