Atmospheric oxidation of pyrite; maximizing the elemental sulphur yield

本研究方案是关于黄铁矿-难选矿石的常压前处理和金的回收。这个 从简单矿石中提金的典型方法是在稀氰化液中浸出矿石。浸出 难选金矿比简单金矿复杂得多。通常情况下，金矿矿石的耐火性是 由于硫化物的存在，如黄铁矿(FeS_2)。在难选矿石中，细小的金粒通常 金被包裹在硫化物基质中，不能被氰化物溶液接触，导致金的回收率很低。 处理难处理的金矿石需要一个额外的步骤，称为氧化 前处理，分解硫化物结构，释放包裹的金粒子。然而， 硫化物，如黄铁矿，非常稳定，它们的分解需要很强的氧化条件。烘焙 和加压氧化是两种经过商业验证的硫化物氧化技术。然而， 基于这些工艺建造一座新工厂的成本可能非常高。此外，如果原料矿石中含有 有害元素，如砷，那么焙烧过程可能会将这些释放到环境中。罚则 元素是剧毒的，释放到环境中的危险限制了焙烧过程 申请。 该方案将研究一种黄铁矿氧化的常压浸出方法。我们的目标是开发一种 具有高氧化动力学和高元素硫产率的工艺。这个过程的动力学应该是 高，以使过程的经济性是合理的。高的氧化动力学将通过以下方式获得 碳基催化剂在该工艺中的应用。元素硫的高产量也是重要的 实现，以消除过量硫酸的产生。氧化物质的金浸出将 通过巴里克黄金公司最近商业化的工艺在硫代硫酸盐溶液中进行。 6名总部人员(2名博士生和4名暑期学生)将参与该项目，并将获得广泛的知识 提取冶金学。HQP将接受培训，以满足加拿大采矿业的需求。

This research proposal is about atmospheric pre-treatment and gold recovery of pyrite-refractory ores. The typical method for gold extraction from simple ores is to leach the ore in a dilute cyanide solution. Leaching of the refractory gold ores is more complex than simple ores. Typically, the refractoriness of the gold ores is due to the presence of sulphides, such as pyrite (FeS2). In the refractory ores, fine gold particles are usually encapsulated in the sulphide matrix and are inaccessible to cyanide solution, resulting in poor gold recoveries. Treatment of the refractory gold ores requires one additional step in the process, known as oxidative pre-treatment, to decompose the sulphide structure and liberate the encapsulated gold particles. However, sulphides such as pyrite, are very stable and their decomposition requires strong oxidizing conditions. Roasting and pressure oxidation are two commercially-proven technologies for oxidation of sulphides. However, building a new plant based on these processes can be extremely costly. Additionally, if the feed ore contains penalty elements, such as arsenic, then the roasting process may release these into the environment. Penalty elements are highly toxic and the risk of their release into the environment limits the roasting process application. This proposal will investigate an atmospheric leaching method for pyrite oxidation. The goal is to develop a process with high oxidation kinetics and high elemental sulphur yield. The kinetics of the process should be high to make the economics of the processes justifiable. The high oxidation kinetics will be obtained by application of carbon based catalysts in the process. High yield of elemental sulphur is also important to achieve, in order to eliminate excess sulphuric acid generation. Gold leaching of the oxidized material would be performed in thiosulphate solution by the recently commercialized process by Barrick Gold Corp. Six HQPs (2 PhD and 4 summer students) will be engaged in this project, and will gain extensive knowledge of the extractive metallurgy. The HQPs will be trained to meet the needs of the Canadian mining industry.