Hydrological Evaluation of Gold Leach Pad Rinsing

Zhan, Guosheng; Haggarty, Steve; Ludwick, William

doi:10.1007/s10230-012-0193-5

Cited by 4 publications

(4 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…High gold prices can make re-washing with cyanide solution 'heaps' of extracted ore economically viable. (See Zhan, et al, 2012 for more details about the mineral extraction process at the Pierina site). 10.…”

Section: Discussionmentioning

confidence: 99%

Emotional subjectivities and the trajectory of a Peruvian mining conflict

Balderson

2022

Environment and Planning E: Nature and Space

View full text Add to dashboard Cite

The trajectory of socio-environmental conflicts remains difficult to predict. In the case study explored in this article, attention to the emergence of emotional subjectivities helps us better understand the timing of the conflict and the style of contestation at the site. The data are drawn from interviews and observations of the ‘dialogue table’ meetings that took place between representatives from the BarrickGold run Pierina mine in Ancash, a highland area in Peru, and the nearby village of Mataquita to try and resolve a conflict over access to water. The paper identifies three ways that the emotional climate at the site influenced the conflict trajectory. Firstly, it was heightened fear for future water availability and increased feelings of hope that the mining company could be held to account for the hydrosphere disruption that triggered the conflict. Secondly, the Mataquitans tried to elicit feelings of compassion in mining company representatives whilst the company acted to repress them, fearing that they could endanger profit-making at the site. Finally, the inconsistent behaviour of the mining company and their ad hoc Corporate Social Responsibility allocations produced a moral-emotional critique of mine behaviour and a climate of distrust within and between villages. The emotions produced by interactions between actors reduced the likelihood of a more coordinated response to the problems at the site, conveniently serving the agenda of the mine.

show abstract

Section: Discussionmentioning

confidence: 99%

Emotional subjectivities and the trajectory of a Peruvian mining conflict

Balderson

2022

Environment and Planning E: Nature and Space

View full text Add to dashboard Cite

show abstract

“…In fact, the most common definition of a pore volume used to describe the process of heap stabilisation by rinsing is the amount of water required to fill all the pore space within and between all of the particles in a heap minus the quantity of water that will remain in the heap due to matric suction after it is allowed to freely drain (field capacity). Recent work by Zhan et al (2012) indicates that less than 1.5 pore volumes would be required to reduce WAD cyanide concentrations below 0.2 mg/L, assuming reduction by dilution alone.…”

Section: Early Closure Regulationsmentioning

confidence: 99%

The evolution of cyanide heap leach closure methods

Parshley¹,

Willow²,

Bowell³

2012

Proceedings of the International Conference on Mine Closure

View full text Add to dashboard Cite

The last two decades have seen a significant evolution in the approaches used to close gold heap leach pad facilities in an environmentally responsible manner. With the promulgation of new cyanide regulations in the State of Nevada, USA in 1989, the mining industry was faced with the need to develop new methods to safely close cyanide heap leach pads in a manner that eliminated long-term risks associated with cyanide and other chemical constituents that could be discharged from the heap leach pads following closure. Initially, rinsing of the heaps was thought to be the only approach to reduce concentrations of cyanide, and this was reflected in the new regulations as a requirement to rinse heaps, unless other methods could be demonstrated to adequately stabilise the spent ore and solutions. However, the regulations were unclear as to when closure of the heap began and if circulation of process solutions, after cyanide addition ceased, constituted rinsing. Many closure plans developed during the early years immediately following promulgation of the new regulations assumed that rinsing would be done with fresh water in quantities of up to three times the total pore volume of the heap based solely on the results of a study published in 1996 (Cellan et al.). If implemented, this would result in the consumption of significant quantities of clean water in a region where water resources are limited, and the benefits of freshwater rinsing were not always apparent. Rinsing heaps during closure also generated large quantities of additional "process" solutions that required management through other methods, such as forced evaporation, or chemical or biological treatment. By the late 1990s, the mining industry had closed enough heap leach pads to allow review of ideas and to use this to make changes in the regulations and approaches employed by the industry. A better definition of when heap closure begins was needed. The currently accepted criterion for closure was after economic gold recovery ceases. Continued research on this led to the demonstration for closed heaps that additional rinsing after the residual gold recovery period is often not needed to reduce cyanide risks from the heap drainage because the more toxic forms of cyanide volatilise and other deleterious elements become mobile as solutions are recirculated through the heap (Bowell et al., 2009). To address the shortcomings of heap rinsing as the primary method of chemical stabilisation of spent ore, a number of approaches were tried, and many of the early approaches were abandoned in favour of more practical and economic methods which were equally effective. This paper documents the history of heap leach closure approaches since the late 1980s and discusses the evolution of understanding and consequently the methods proposed to stabilise spent heap ore during closure. Data from several closed heaps are presented as illustrations of the progression of approaches to heap rinsing. Current trends in the existing best practice and their probable impact on the focus...

show abstract

“…Indeed, modelling the complexity of flow through the ore matrix is not a simple task due to variability in macro-pores, channelling of solution and preferential flow effects [5]. These effects are generally ignored in models but in reality, they can give rise to solute transport problems and limit reaction kinetics [6][7][8] Techniques based on soil physics to represent the preferential flow, such as dual continuum, dual or random porosity (or permeability), may be included in models.…”

Section: Introductionmentioning

confidence: 99%

Heap Leaching: Modelling and Forecasting Using CFD Technology

McBride

Gebhardt²,

Croft

et al. 2018

Minerals

View full text Add to dashboard Cite

Heap leach operations typically employ some form of modelling and forecasting tools to predict cash flow margins and project viability. However, these vary from simple spreadsheets to phenomenological models, with more complex models not commonly employed as they require the greatest amount of time and effort. Yet, accurate production modelling and forecasting are essential for managing production and potentially critical for successful operation of a complex heap, time and effort spent in setting up modelling tools initially may increase profitability in the long term. A brief overview of various modelling approaches is presented, but this paper focuses on the capabilities of a computational fluid dynamics (CFD) model. Advances in computational capability allow for complex CFD models, coupled with leach kinetic models, to be applied to complex ore bodies. In this paper a comprehensive hydrodynamic CFD model is described and applied to chalcopyrite dissolution under heap operating conditions. The model is parameterized against experimental data and validated against a range of experimental leach tests under different thermal conditions. A three-dimensional 'virtual' heap, under fluctuating meteorological conditions, is simulated. Continuous and intermittent irrigation is investigated, showing copper recovery per unit volume of applied leach solution to be slightly increased for pulse irrigation.

show abstract

Hydrological Evaluation of Gold Leach Pad Rinsing

Cited by 4 publications

References 5 publications

Emotional subjectivities and the trajectory of a Peruvian mining conflict

Emotional subjectivities and the trajectory of a Peruvian mining conflict

The evolution of cyanide heap leach closure methods

Heap Leaching: Modelling and Forecasting Using CFD Technology

Contact Info

Product

Resources

About