General Mining : 29 February 2016 - Mt Cattlin Processing Plant Update

1. million tonnes per annum (Mtpa) will be the first part of the circuit to be energised, rectifying a historical anomaly in the overall flow sheet, specifically, the non‐recovery of any lithium from the fine fraction; defined as

   
   

   The majority of this circuit is being fabricated off‐site and will be installed sequentially from March 2016 onwards. The new circuit will progressively recover spodumene concentrate (and tantalum as a by‐product) in the following steps:

   
   

   • Reflux classification will be used to remove mica;

   • A spiral and table circuit will recover the tantalum;

   • Flotation will produce a fine spodumene concentrate grading 5.2‐5.5% Li2O (the coarse stream will be in the vicinity of 5.5‐5.8% Li2O, producing a blended product of minimum 5.5% Li2O); and

   • A filter belt will be used to remove any excess moisture from the concentrate.

     
     

     The feed source for this fines circuit is ore currently located in the Tailings Storage Facility (TSF). As indicated above, the previous flow sheet recovered none of the lithium in the fine fraction and consequently there is ore grade material (already mined and crushed) available for extraction by General Mining at very low operating costs. This will be sufficient to commission and feed the operation until after the coarse circuit is brought online (see below for further details).

     
     

     In terms of timing, the reflux classifiers will be commissioned first with the rest of the fines circuit progressively activated as refurbishment work continues on the in situ coarse circuit.

     
     

     Crushing Circuit - upgrade options

     
     

     The crushing circuit at Mt Cattlin was built with a nameplate capacity of 1Mtpa, although General Mining has based its projections to date off a more conservative throughput estimate of 800ktpa during the recommencement phase (see ASX release 12/10/2015).

     
     

     General Mining has explored a number of ways to expand crushing capacity to match the throughput rates being built into the wet circuit, up to a potential target of 1.5Mtpa. Of the options explored, the future focus will include:

     
     

     • Dry crushing to 12mm instead of 6mm allowing potential to increase throughput; and

     • Expansion of crushing hours from the historic 12 hours per day (based on existing noise limits) to 16+ hours per day via a number of noise attenuation initiatives.

       
       

       General Refurbishment Works

       
       

       The existing processing facility and supporting infrastructure is also undergoing an extensive refurbishment and upgrade program which includes:

       
       

     • Additional reflux classifiers will substantially improve mica removal (from 15‐20% in the previous finished concentrate to below 5%);

     • New spirals and refurbished tables will comprise the tantalum recovery circuit; and

     • The coarse DMS spodumene circuit will be upgraded and re‐designed to produce a middlings stream back into the fines circuit, reducing spodumene loss to coarse tailings stockpiles and increasing the coarse spodumene concentrate grade.

       Other items such as belts, rollers, pumps and associated equipment are also being replaced or repaired as part of this maintenance program.

       
       

       Timeline

       GMM also confirms its previous advice issued to the market on 21 January 2016 regarding the commissioning timeline:

       
       

     • Fine circuit - by 31 March 2016

     • Coarse circuit (including Crusher) -June quarter 2016

     • Anticipated first shipment of concentrate -July 2016

General Mining Corporation Ltd. issued this content on 29 February 2016 and is solely responsible for the information contained herein. Distributed by Public, unedited and unaltered, on 29 February 2016 01:35:14 UTC

Original Document: http://www.generalmining.com/pdf/asx_releases/29_02_2016/GMM246 2016-02-29 Mt Cattlin.pdf