Modern Mining May 2018

MINING News

WorleyParsons completes update of Wafi-Golpu study

large-scale open pit mining of the Wafi deposit rather than underground mining; however, this was dismissed for various reasons. Subsequent investigations were highly successful in more accurately delin- eating an orebody but further work was required to determine the economic viabil- ity of mining. A number of technical studies across various disciplines was completed post- 2012 which determined a viable business case for development of a large-scale deep-level block cave mine. The outcomes of the Pre-Feasibility Study initiated a Pre-Feasibility Optimi­ sation Study phase of work. This phase of work contemplated alternative options focused more towards a smaller, scalable, lower capital cost start-up mine. In November 2013, the Pre-Feasibility Optimisation Study was commissioned with the purpose of developing a single, preferred business case to a pre-feasibility study level of definition. WorleyParsons RSA were appointed by the WGJV as the Pre-Feasibility Optimisation Study con- sultants. Prior to commencing the study, WorleyParsons utilised the StepWise meth- odology to develop, assess and shortlist preferred options. Bailie says that by following the Step­ Wise process, theWGJV andWorleyParsons RSA were able to reframe a new business case for the Wafi-Golpu project by looking at a small-scale build-up and programme of ongoing work that led to the Feasibility Study, and later the Feasibility Study Update. Initially fourteen conceptual mining options were developed and assessed with the associated technical and business case, which was narrowed down to three preferred options to carry forward into the Pre-Feasibility Optimisation Study. WorleyParsons RSA completed the study in 2014 which recommended a staged development approach involving the mass mining method, block caving, commenc- ing with the development of a smaller lower cost start-up mine (Stage 1 project). The Stage 2 project focused on a life of mine plan as a follow-on from the Stage 1 project, with the objective of identifying and evaluating options to maximise and enhance the value of the Golpu orebody through optimising access and the exploi-

Processing plant of the greenfield Wafi-Golpu project.

Project delivery company WorleyParsons RSA has recently completed the Feasibility Study Update (FSU) for the Wafi-Golpu Joint Venture (WGJV ) in Papua New Guinea, giving the greenfield Wafi-Golpu project a revised execution plan going forward. Bryan Bailie, the Executive Project Director for WGJV, says, “The Feasibility Study Update developed by the WGJV, WorleyParsons RSA and other consultants sets out an improved business case for the Wafi-Golpu project, and the study confirms the preferred technical options to deliver the block cave mining project safely and with appropriate consideration given to environmental, social and cultural heritage stewardship.” The FSU report incorporates findings from earlier pre-feasibility and feasibil-

ity studies and draws on extensive data collection undertaken since 2016. It also forms an integral component of the revised Proposal for Development in support of the Special Mining Lease appli- cation which was submitted to the Mineral Resources Authority (MRA) by the Wafi- Golpu Joint Venture in August 2016. Wafi-Golpu is a joint venture copper- gold project that is owned 50/50 by Harmony Gold Mining Company South Africa and Newcrest Mining in Australia. It is located in the Morobe Province of Papua New Guinea, approximately 65 km south- west of the city of Lae. Various approaches to development (including infrastructure configurations) have been considered in the investigations for the development of the Wafi-Golpu deposits. Early investigations considered planned for resource delineation in 2018 to be included in the alluvial JORC resource update. This mining block is located close to the treatment plant. Lucapa says the frequent recovery of large and premium-value diamonds from new areas along the Cacuilo River val- ley continues to illustrate the uniqueness and potential of the Lulo diamond con- cession. Lulo has already recovered ten plus‑100‑carat diamonds to date, includ- ing Angola’s two biggest recorded white Type IIa gems weighing 404 carats and 227 carats. 

Large pink diamond recovered at Lulo in Angola Lucapa Diamond Company, listed on the ASX, and its partners, Endiama and Rosas & Petalas, have announced the recovery of a large gem-quality pink diamond from the Lulo diamond project in Angola.

The 46-carat pink is the largest gem- quality coloured diamond recovered to date from the Lulo mining operations, eclipsing the 43-carat yellow gem recov- ered in January 2018 and the 39-carat pink recovered in September 2016. Significantly, the 46-carat pink, along with other large Specials, was recovered from new Mining Block 4, which is an area

8  MODERN MINING  May 2018