The Company completed Laboratory scale test work between 2011 and 2013 which included batch smelting test, slag testing, agglomeration behaviour of the ore, Liquidus measurement of FeNi slag under conditions corresponding to electric furnace smelting, performance of the nickel laterite in rotary kiln processing and evaluation of briquetting behavior. These laboratory tests carried out showed that the ore was suitable for processing using the RKEF process.
Pilot plant testing of the drying and agglomeration step and piloting of the full RKEF process flowsheet (excluding refining) to confirm final operating characteristics were recommended in the 2014 PFS report. This pilot testing was carried out in the first and second quarters of 2015.
A fully integrated pilot test of the RKEF process comprising ore preparation, drying and agglomeration, calcination and electric furnace smelting, including slag and metal granulation, was carried out in April/May 2015. The pilot test work facility at the Morro Azul plant in the State of Minas Gerais, Brazil was used for the test. A total of 160 wet tonnes of ore, representative of the planned operational feed, were processed. This ore was collected from selected sites within the Pequizeiro deposit in a bulk sampling exercise in early 2015 using wide diameter auger drilling.
Highlights from the pilot plant campaign include:
Horizonte is committed to best practice in sustainability and management of water and gas emissions is an important part of the process plant. All gases produced will be cleaned before discharge via a filter system. All water will be treated and recycled for re-use in the plant as this is a closed circuit plant, meaning that no water will exit the plant area into the environment.