Cradle Arc confirms applicability of DMS to its producing Mowana Copper Mine

Posted by Daniel Gleeson on 31st January 2018

Cradle Arc, the African focused base and precious metals exploration and production company, has received an independent test report from SGS South Africa detailing analysis sampling results and confirming the applicability of Dense Media Separation (DMS) for its flagship asset, Mowana copper mine in Botswana. Accordingly, it remains the Board’s intention to pursue a DMS installation in due course and further updates will be provided as necessary as the development plan for the upgrades to the Mowana processing plant progresses.

Overview

  • DMS identified as a low capex expansion option to potentially increase production at Mowana to approximately 22,000 t/y of copper in concentrate
  • DMS could increase throughput to approximately 2.6 Mt/y with reduced cash costs, leading to an increased NPV of up to $245 million (from the current base case NPV of $87 million)
  • Test work has demonstrated that DMS pre-concentration can be deployed at Mowana on all low oxide ores (those that contain less than 25% acid soluble copper)

The following key metrics were derived by the company from the independent test work:

  • A mass yield of 30-40%, and an expected copper recovery of in excess of 85% can be expected
  • Mill feed grades in excess of 2% can be expected, nearly double the current ROM
  • An optimal crushing top size of 10-12mm should be designed for with respect to the upgrade project
  • Good rejection of gangue minerals is achieved, including carbon and silicon (with more than 75% being rejected)
  • Based on the outcome of this test work, Cradle Arc intends to move forward with a development plan for the upgrades to the Mowana processing plant

Initial DMS preparatory work is to be completed within Q1 2018. Cradle Arc is also generating a new block model for the resource at Mowana, which will enable it to complete new mining schedules that incorporate the DMS study results as well as the additional knowledge gained from a re-logging exercise.

To complete the technical aspects of the DMS upgrade project, Wardell Armstrong International Ltd has been appointed to re-model the Mowana resource. Such modelling includes the re-logging of drill core and confirmatory assay on selected samples allowing a fuller interpretation of the data base. As a result of this re-modelling and the abovementioned SGS work, the company anticipates that it will then be able to update the Mowana Resource and Reserve statement.

Commenting today, Kevin van Wouw, CEO of Cradle Arc said: “Our expectation that DMS upgrades should be deployed at Mowana has been confirmed by SGS’s report. We are now focused on working closely with our selected contractors to finalise the budget and implement the strategy to upgrade the processing plant. We are confident that we can rapidly move the Mowana mine from operating at its current nameplate capacity capable of producing 12,000 t/y Cu, to operating at an improved capacity, that should enable copper production to increase to, potentially, more than 20,000 t/y Cu. This is expected to dramatically improve cash flows and the net present value. We currently anticipate that we will complete the initial phase of DMS preparatory work within Q1 2018 and further updates will be provided in due course.

“Concurrent with this work, we are generating a new block model for the resource at Mowana, which will allow us to complete new mining schedules incorporating these results as well as the additional knowledge gained from our re-logging exercise. We expect both of these work streams to be completed during this quarter, allowing the upgrade project to move forward expeditiously.”