Understanding the role of catalysts in the leaching of sulfide minerals

了解催化剂在硫化物矿物浸出中的作用

• 批准号: 155122-2011
• 负责人: Dixon, David
• 金额: $ 1.82万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569420
• 关键词: Understanding; role; catalysts; leaching; sulfide

Chalcopyrite is the world's most abundant copper mineral, accounting for roughly 70% of the world's total copper production. Most chalcopyrite concentrates are processed by smelting. However, smelters release sulfur dioxide gas (the leading cause of acid rain), cannot handle impurities such as arsenic (a common element in many copper orebodies), and are typically very remote from copper minesites (incurring high shipping charges and contributing to greenhouse gas emissions). Leaching presents a promising alternative to smelting. Leaching emits no gases, can handle arsenic in an environmentally sensitive manner, can be applied to low grade materials, and can be operated directly at minesites. However, chalcopyrite is among the most difficult of all sulfide minerals to leach, as it tends to form passive layers under typical oxidative leaching conditions. Many processes have been developed over the years to overcome this passivity, relying on a combination of ultrafine grinding, highly corrosive chemical additives (eg, chloride), and/or high temperatures and pressures to ensure rapid leaching. However, most have proven too costly or too complex for industrial implementation, and none have achieved broad commercial success. Recently, a fresh approach to leaching primary copper concentrates has been developed at UBC, based on the use of inexpensive catalysts such as pyrite and activated carbon to accelerate the rate of chalcopyrite leaching under atmospheric conditions in mildly corrosive sulfate solutions, without fine grinding or chemical additives. These catalysts have also proven effective for the treatment of enargite, a highly refractory copper-arsenic sulfide mineral of increasing economic importance which is unsuitable for smelting. Most recently, we have discovered that pretreating pyrite samples with miniscule quantities of dissolved silver prior to leaching dramatically enhances their effectiveness as catalysts. The objective of the proposed research is to develop an understanding of the mechanisms underlying the catalytic effects of pyrite and activated carbon on primary copper sulfides, and to employ this understanding in the development of industrially robust leaching processes.

黄铜矿是世界上储量最丰富的铜矿物，约占世界铜总产量的70%。大多数黄铜矿精矿是通过熔炼加工的。然而，冶炼厂会释放二氧化硫气体（酸雨的主要原因），无法处理砷（许多铜矿体中的常见元素）等杂质，并且通常距离铜矿区很远（产生高昂的运输费用并导致温室气体排放）排放）。 浸出是熔炼的一种有前途的替代方法。 浸出不排放任何气体，可以以对环境敏感的方式处理砷，可以应用于低品位材料，并且可以直接在矿场进行操作。然而，黄铜矿是所有硫化物矿物中最难浸出的矿物之一，因为它在典型的氧化浸出条件下往往会形成钝化层。 多年来，人们开发了许多工艺来克服这种被动性，依靠超细研磨、高腐蚀性化学添加剂（例如氯化物）和/或高温和高压的组合来确保快速浸出。 然而，事实证明，大多数技术对于工业实施而言成本过高或过于复杂，而且没有一个取得了广泛的商业成功。 最近，UBC 开发了一种浸出初级铜精矿的新方法，该方法基于使用廉价的催化剂（例如黄铁矿和活性炭）来加速在大气条件下在轻度腐蚀性硫酸盐溶液中浸出黄铜矿的速率，无需精细研磨或化学处理添加剂。这些催化剂也被证明可有效处理铜砷矿，这是一种高度难熔的铜砷硫化物矿物，其经济重要性日益增加，但不适合冶炼。最近，我们发现在浸出之前用微量溶解的银对黄铁矿样品进行预处理可显着提高其作为催化剂的有效性。 拟议研究的目的是了解黄铁矿和活性炭对初级硫化铜催化作用的机制，并将这种理解应用于工业稳健浸出工艺的开发。