JOHANNESBURG (miningweekly.com) – The new cost-slashing, time-saving, capital-unlocking, mine-broadening and cobalt-saving platinum technology, driven by diversified mining company Pallinghurst and South Africa’s State-owned Industrial Development Corporation (IDC), is gaining impressive international momentum as an initiative that is transformational for an entire industry.
Not only will construction of a new Kell concentrate-to-refined metals plant begin in South Africa this year at Pallinghurst’s Sedibelo platinum mine in North West province, but a far-reaching agreement was struck this week for up to five Kell plants to be built in neighbouring Zimbabwe, where it has been agreed that over time all the platinum concentrate produced in Zimbabwe will be Kell processed.
As the plants will be 51% Zimbabwe-owned, Zimbabwean indigenisation requirements will be fulfilled for the platinum mines passing concentrate through the Kell plants in Zimbabwe and no longer sending concentrate out of the country.
The lack of power capacity in Zimbabwe and high cost of establishing smelters and refineries is taken care of by Kell, which uses less than a fifth of the power required for smelting and refines the platinum group metals (PGMs) as part of the process.
It will also mean that South Africa-linked platinum-mining companies operating in Zimbabwe will no longer be faced with the upcoming 15% duty on all concentrate leaving the country.
When Pallinghurst’s Sedibelo company was launched in 2012, Mining Weekly Online witnessed Pallinghurst chairperson Brian Gilbertson, Pallinghurst CEO Arne Frandsen, Kell developer Keith Liddell, IDC CEO Geoffrey Qhena and IDC mining executive Abel Malinga commit to the development of Kell, to ensure the local beneficiation of South Africa’s PGMs could be done in South Africa competitively.
Now, five years later, Kell is making it possible for local beneficiation to take place super competitively, not only in South Africa, but also in neighbouring Zimbabwe, the world’s second major platinum destination.
Kell also opens the way for lowest-cost local manufacture of PGM-using autocatalytic converters and platinum-using fuel cells, if not in South Africa then in Zimbabwe.
Kell reduces mining-to-refining time to a week instead of a month plus, uses less than a fifth of the electricity needed for smelting, replaces a smelting plant that costs $1-billion with a modular hydrometallurgical plant that costs $100-million, widens mining scope by throwing chrome-ore content caution to the wind, adds tens of millions of dollars to the revenue stream by recovering the cobalt metal that smelting obliterates and eliminates all pungent and toxic sulphur dioxide (SO2) emissions that smelting causes.
“It’s green, it’s right and it’s here in South Africa,” Frandsen enthused to Creamer Media’s Mining Weekly Online in an interview.
By removing the chrome constraint, mining can be optimised, particular in the case of upper group two (UG2) reef concentrators, which is worth between 5% and 10% additional recovery.
Recovery of currently burnt cobalt would add $50-million to $60-million to the revenue stream of South African platinum mining companies and $15-million to $20-million in Zimbabwe.
Zimbabwe’s Cabinet approved the proposal to establish a Kell technology PGM refinery in Zimbabwe in March and a memorandum of agreement was signed this week between the Pallinghurst- and IDC-owned Kelltech and the Zimbabwe Mining Development Corporation (ZMDC).
The obligations of the Ministry, under Mines and Mining Development Minister Walter Chidhakwa, is to provide adequate concentrate feedstock to ensure full capacity utilisation of the Kell technology PGMs refinery.
The government of Zimbabwe has thus guaranteed that Kelltech will receive all the concentrate it needs as feedstock to meet the capacity of up to five Kell plants.
Zimbabwe is mimicking South Africa’s legislation, which lays down that the concentrates have to be processed in South Africa and, more specifically, if a Kell plant is designed with a capacity of, say, 200 000 t a year a year, that volume of concentrate must be passed through that plant.
The memorandum of understanding lays down that Kelltech will beneficiate all of the PGMs produced in Zimbabwe within five years.
Pallinghurst has promised that it will break ground this year in Zimbabwe and also at Sedibelo in South Africa and construction will be taking place north and south of the Limpopo, slightly staggered so that crew can move from the one site to the other.
Being modular, additional plant capacity can be phased in, allowing capital to be spent over an extended period of time instead of all at once.
The elements used by the Kell plants are available off-the-shelf, with the intellectual property residing in their configuration.
A Kell plant can be put together in a year and be commissioned in 18 months.
“It’s quicker, requires much less capital, is far cheaper to operate and doesn’t pollute. It has all the great attributes, but whenever you come with something new, everyone looks for the flaws and we can say, comfortably, that after all the runs we’ve done and the bankable feasibility study we have completed, that this works,” Frandsen told Mining Weekly Online hours after the Zimbabwe agreement was concluded.
In partnering with the IDC, Pallinghurst has strong local support for Kell, and this support has now extended across the border into Zimbabwe’s Great Dyke, which has some of the world’s best platinum.
But Zimbabwe’s regulated indigenisation and beneficiation has up to now not been implementable owing to the country’s lack of electricity capacity for conventional smelting and refining and the high cost of building smelters and refineries in relation to the potential throughput.
It was against that background that Pallinghurst two years ago initiated talks in Zimbabwe that ran parallel to its construction plans in South Africa.
“The one doesn’t exclude the other. We saw quite quickly that if we can implement a solution for Zimbabwe that can really make a big difference for the country. Not only can we beneficiate locally but we have the means to do it super competitively,” said Frandsen
The company met with the Minister of Mines, who quickly became a big supporter of Kell because it answered the queries of those who cited the high cost of smelting and refining as the reason why full beneficiation from concentrate to refined platinum, palladium, copper, nickel and cobalt metals was prohibitive and who also queried where they would source electricity in power-short Zimbabwe.
WASTING VALUABLE ELECTRICITY ON WASTE
Of every 100 g of concentrate produced conventionally, 95% is worthless waste, known as gangue, and only 5% contains the valuable metals.
To get the 5%, the 95% is also heated to the very high temperatures of 1 300 °C and 1 400 °C to melt them.
By processing 95% of valueless minerals, not only is electricity squandered, but large quantities of slag are produced, which contains cadmium, selenium and some arsenic.
The matte produced has to be put into a converter through which oxygen is blown and this results in the emission of SO2, which leads to acid rain.
The matte is then ground and re-leached to remove the base metals and the residue from that procedure goes into the PGM refineries.
In the nineties, when Liddell was looking for alternatives to smelting in case Kroondal platinum mine, in the North West, was unable to ship concentrate out of the country, he began studying ways of leaching the 5% of sulphides that contain the PGMs and the base metals and isolating the 95% of gangue minerals.
He applied the leaching method used on matte to the concentrate itself and stumbled on the way PGMs could be liberated, as now happens with Kell.
Backed by Pallinghurst, the IDC and other shareholders, Liddell has since built two pilot plants, one at Sedibelo and the other in Perth, which has processed concentrates from a number of different producers, extending from Southern Africa’s PGM producers to North America’s miners of polymetallic ores.
The company has spent years testing, re-testing and super-testing Kell, particularly at Kelltech’s sizeable plant in Perth, which is described as being of mini-commercial scale.
All the years of diligent research and development have now paid off.
Sedibelo in the North West province dispatched 165 000 oz of four element PGMs in the 12 months to December 31, and is willing to make the Kell plant available to others.
The plant at Sedibelo, which will have a capacity to process 300 000 oz of PGMs a year, is budgeted to come in at less than $100-million.
Kell processes UG2 reef, Merensky reef, platreef, Great Dyke reef, North America’s polymetallic ore and even refractory gold.
The spinoffs on the gold side are that cyanide is not required in the processing and the output is 99.99% refined gold, with the potential to unlock major synergies in locations that host both PGMs and refractory gold.
A slightly modified Kell is also successful for reprocessing recycled platinum.
Cobalt, now in a strong potential earnings position because of its growing use in electric vehicles, is recovered.
Because the presence of chromite is no issue at all, UG2 concentrators can be optimised for greater PGM recovery than when being forced to meet the chrome constraints in the concentrate.