Had a chance today to look through the proceedings of the upcoming conference Heap Leach Solutions 2014 scheduled in Lima, Peru for November 10 through the 13th, 2014.
The paper that caught my eye and caused me to stop and read it is titled Leach Pad Cost Benchmarking. The authors are Mark E. Smith and Denys Parra of Anddes Asociados SAC, Peru. Two famous folk in the field of heap leach pads. You will have to wait for the proceedings to be published to get a copy, but for now let me quote from the paper.
Here is the paper abstract:
The cost of construction of the leach pad is an important part of the total capital cost of any heap leach project, whether a green-field development or expansion of an existing operation. The authors present and discuss costs from 48 phases of work on 28 heap leach projects in 8 countries, including North and South America, Africa and Asia. Costs were compiled from feasibility studies, detailed designs, NI43-101 technical reports, and as-built analyses. In a few cases, when the detail was suitably advanced, costs from prefeasibility studies have also been used. All costs are presented in 2014 United States dollars (US$) using an escalation rate based on the 10-year average ENR Construction Cost Index.
This data and the accompanying analyses should provide assistance to engineers and owners in preparing project cost studies. It may be useful to reviewers, investors, regulators, and sureties in determining the reasonableness of third party cost estimates. It may also help in the future to determine trends in heap leach costs (for example, relative to general construction cost escalation). This paper will also discuss the purpose of and methodology used in performing a benchmark study, which may be of broader application.
Here is just one of the many tables of data in the paper:
Table 1: Leach pad costs by country (2014 dollars)
|Country||Number of projects||Earthworks costs, average US$/m2||Liner system costs, average US$/m2||Total leach pad costs, US$/m2|
There are six more tables of information about costs. All valuable information. Hence the authors conclude:
As a closing observation, many of the differences between the various costs are in the upper limit of the range data. While the lower bound varies in the narrow spread of only US$9.39/m2 (US$21.53 to US$30.92), the spread of upper bound costs is a robust US$61.22/m2 (US$34.46 to US$95.68). Thus, cost-related risk reduction efforts should concentrate on addressing the factors that may affect the higher range figures, principally high rainfall sites and the use of valley leach pad technology, including its implementation.
A tremendous paper this one. Get it when available–or maybe contact the authors through their companies and ask them for a copy. I am sure they will be proud to oblige.