Dec '11/Jan '12

Standards

Best practice guidelines for mineral processing now available

By D. Fragomeni, L. Urbanoski, T. Lipiec and C. Fleming

National Instrument 43-101 Standards of Disclosure for Mineral Projects (NI 43-101) is a set of rules and guidelines for reporting and displaying technical information related to mineral projects owned or explored by mining companies that report these results to the Canadian public. This includes foreign mining companies that trade on Canadian stock exchanges and private mining companies that make technical information available to the public. On June 30, 2011, NI 43-101 was updated by the Canadian Securities Administrators (CSA), and this past August, CIM Council approved the final version of the highly anticipated Best Practice Guidelines for Mineral Processing (BPGMP).

NI 43-101 has specific rules regarding technical information that requires the consideration of metallurgy and mineral processing. A mineral resource estimator requires input regarding metallurgy for the appropriate assumptions used in determining a mineral resource, and metallurgists or process engineers should always be involved in the technical considerations applied to mineral reserves. In addition, several items in a technical report require particular information and discussion related to metallurgy and mineral processing, including Item 13 (Mineral Processing and Metallurgical Testing) and Item 17 (Recovery Methods).

In 2010, during the 42nd Annual National Meeting of the Canadian Mineral Processors Society of CIM (CMP), a motion from the floor was passed requesting that CMP perform a review of the mineral processing components of NI 43-101 and produce recommendations or best practice guidelines. A subcommittee representing the main interest groups – operations, engineering and testing laboratories – was formed, which included: Larry Urbanoski, independent consulting metallurgical engineer, LSU Consulting; Tony Lipiec, principal process engineer, AMEC; and Chris Fleming, senior metallurgical consultant, SGS Lakefield Research.

The goal of the revision was to produce workable, practical and non-prescriptive best practice guidelines (BPG) by compiling industry best practices. At the same time, it needed to maintain the flexibility for the Qualified Person (QP) to determine what best fits the company and project risk profile while maintaining overall accountability.

The subcommittee worked diligently to produce a draft by the fall of 2010. Then-CIM president Michael Allan and CIM president-elect Chuck Edwards were instrumental in soliciting CIM resources currently engaged in the overall review of NI 43-101, including Robert Holland and Neil Gow, to provide support for the process.

In addition to the Best Practice Guidelines, an appendix was produced that describes support for the guidelines in tabular form. A summary table indicates the level of support work for the technical report expected from the studies, with specific reference to the project stages: scoping, prefeasibility and feasibility. In addition, a much-needed glossary of terms was included to define certain mineral processing jargon. The BPGMP boundary limits are defined from mill feed to concentrate or bullion and tailings. Guidelines on the assessment of smelting or hydrometallurgical processes are not considered.

Through a consultative process, the CMP subcommittee met its objectives of a workable, practical and non-prescriptive set of best practice guidelines for the testing and evaluation of mineral resources related to the ore beneficiation process. Guidelines on sample selection, grindability testing, recovery processes and even reference to assessment of environmental consideration from ore to concentrate or bullion have been included.

The BPGMP is a reference for process engineers acting as QPs involved in producing NI 43-101 technical reports. It provides an indication of the work required in the design of beneficiation processes at various project stages, in order to support the declaration of resources and reserves. The guidelines also allow for the assessment of risk by the QP and selection of sampling, testing and design requirements based on company and deposit risk profile.

The BPGMP, appendix and glossary of terms can be found at www.cim.org/standards.


Dominic Fragomeni is a director of Xstrata Process Support. He is frequently involved in mineral processing flowsheet development in base metals and gold, and has a background in plant operations management and metallurgical support.

Larry Urbanoski is an independent consulting metallurgical engineer with a background in mineral processing related to concentrator operations, mineral project evaluation and development programs.

Tony Lipiec is a principal process engineer at AMEC with a background in base and precious metals processing. He is frequently involved in the preparation of NI 43-101 technical reports.

Chris Fleming is a retired SGS Lakefield Research executive and is now a senior metallurgical consultant with SGS. He is a specialist in hydrometallurgy and gold processing technologies.

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