EcoHoist announces that BHP’s Think and Act Differently group has commissioned an “impartial consultant” to perform a commercial analysis of the EcoHoist at a BHP Copper SA proxy mine.
The EcoHoist aims to improve on traditional vertical hoisting systems by substantially reducing the size of the required mine shafts through the use of a vertical bucket elevator that can operate inside two small diameter mine shafts. This reduction in mine shaft size leads to a reduction in capital cost and construction time compared with skip hoist systems, the company says.
The EcoHoist operates on electricity and provides the opportunity for mines using conventional diesel-powered load and haul fleets to simultaneously cut production costs and decarbonise, according to the company.
The study was based on a mine producing 10 Mt/y of ore from 1,000 m underground considering an expansion of production rate by 2 Mt/y, up to 12 Mt/y.
In the base case, this expansion required 10 additional diesel haul trucks and the construction of an additional access decline.
The EcoHoist case required the construction of two small diameter mine shafts and the installation of an EcoHoist continuous bucket elevator running on clean electricity.
The capital cost for the trucking base case included expenditure for 10 trucks at A$3 million ($1.94 million) each, and A$100 million for the decline for a total capex of A$130 million.
In the EcoHoist case the estimated capital cost for the full system was A$75 million including three trucks to transport ore to the loading station. The capital cost for the EcoHoist system was provided by EcoHoist.
Based on this, the EcoHoist scenario delivered the extra 2 Mt/y of ore to the surface for a saving in capital cost of A$55 million (42% cheaper).
Importantly, EcoHoist also almost halved operating costs. The base case haulage cost was A$13.3/t whereas the haulage cost in the EcoHoist scenario was A$6.8/t, including an additional underground loader and underground crusher.
The study found that the lower capital cost and lower operating cost of the EcoHoist resulted in a significantly higher nominal incremental net present value of A$131 million.
Separate to the significant economic benefits, EcoHoist offered substantial reductions in trucking CO2 emissions with the base case estimated (by EcoHoist) to produce 17,000 t/y of CO2, while the EcoHoist scenario only produced 2,000 t/y of CO2.
EcoHoist’s next step is to build a technology demonstrator to confirm its capability to support BHP and other mining companies achieve their goals of maximising production of key commodities like copper, while reducing greenhouse gas emissions and delivering attractive shareholder returns, it says.