HEAP LEACHING AND SX
ALTA 2020
YEARS
Nickel-Cobalt-Copper
Uranium-REE
Gold-PM
In Situ Recovery
Lithium & Battery
Technology
Conference & Exhibition
23-30 May, Perth, Australia
100+ papers
30+ countries
Call for Papers
Forums and Panels
Hydromet Processing of Ni-
Co-Cu Sulphides
Application of Membranes
Cyanide Alleviation &
Alternative Lixiviants
Application of ISR to Copper
Trends in Battery Technology
of the BASF LixTRA reagent shows efficacy as a leaching aid. The results are
at least as good as the lab scale testing.”
He said there was a strong correlation between the increase in ore size
and the effectiveness of the reagent. “Since the leaching aid is producing a
physical effect and not acting as a lixiviant, it is necessary to keep the
concentration at a level where the physical behaviour of the system is
optimal,” Bender said.
While a minimal 25 ppm dosage appears to be required, higher dosages
might be necessary when ore particles are very small, he added.
AIM-listed Alexander Mining recently said it is looking to divest the
proprietary hydrometallurgical mineral processing technologies that come
under its wholly-owned MetaLeach subsidiary and, judging by recent
updates, it could soon find a buyer.
In this same feature last year, we reviewed the characteristics of
Alexander’s AmmLeach ® patented technology, which comes under the brief
of MetaLeach.
In an update earlier this year, the company said Accudo Metals, which
has a licence entitlement for up to five mining projects in Australia to use
the leaching technologies, was in discussions with several companies
looking to deploy the technology.
Meanwhile, the company said test work was currently underway using
Alexander’s HyperLeach™ process on a nickel concentrate from an existing
commercial operation. Alexander talked up the use of HyperLeach, which
operates under ambient temperature and pressure conditions, in this same
article last year, saying the process could be applied to low-grade copper,
nickel, cobalt and molybdenum ores and concentrate.
The aim of this specific trial is to leach around 50% of the contained
nickel and cobalt and produce a mixed sulphide precipitate which is free
from copper, arsenic and iron, Alexander said. “The sulphide will be
blended with the leach residue and sold for further processing as a low
arsenic material.”
The company said, if test work proved successful, further developmental
work would be proposed in partnership with the concentrate producer.
Another development worth keeping an eye on is FLSmidth’s Rapid
Oxidative Leaching (ROL) process, which the company says overcomes three
major copper industry challenges – declining ore grades, increasing levels
of arsenic and other impurities, and reduced production from existing
solvent extraction (SX) and electrowinning facilities due to falling recoveries
from heap leach operations when transitioning from oxide to sulphide ores.
Earlier this year, the company said it was testing concentrates from
several interested copper miners at its ROL pilot plant in Salt Lake City, US,
and at a third-party independent laboratory. “The purpose of these tests is
to establish data for the customers to determine if they would like to move
ahead with prefeasibility studies,” FLSmidth explained.
During 2017-2018, the concentrates from one customer were tested and
indicated a positive return on investment. “We have agreed with this
customer to supply equipment and operate a demonstration-scale ROL
process plant at their facility in South America,” FLSmidth said, adding, “this
is an important step in scaling up and commercialising the ROL process”.
In addition to copper, the company has tested ROL with refractory gold
and it has proven possible to apply the technology in the laboratory to
significantly improve gold recovery, it said.
“We are currently working with several gold producers in research and
development of this process, with the goal of potentially moving on to pilot
scale testing in 2019,” the company concluded earlier this year.
Going with the flow
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When moving further downstream, it is hard to look past Finland-based
Outotec and its array of metallurgical processing technologies from any
discussion on SX technologies.
IM spoke to Timo Nivala, Head of the Global Sales for the
Hydrometallurgy business line, recently to find out what mining customers