Ore export ban readies lithium for boom

23 Dec, 2022 - 00:12 0 Views
Ore export ban readies lithium for boom lithium

eBusiness Weekly

The decision this week to ban export of lithium ores and inadequately processed lithium before the second formal mine enters production early next year should avoid a lot of problems, as well as increase the actual value of lithium exports.

The hard rock deposits in Zimbabwe, estimated to the largest in Africa, produce lithium in two major ores. The most common is petalite, the most common, and spodumene. Both are lithium aluminium silicate compounds, the petalite containing a little more silicate. Both occur as crystals embedded in the surrounding rock, and that is where one danger of artisanal mining occurs.

The ore formation makes it easy to identify, and so blocks of the basement rock could be cut out. In theory crystals can be cut out of the rock, although this would be a lot harder but some crystals can be large enough to see. While preventing artisanal miners from jumping claims, there is the extra danger of environmental damage that needs to be contained.

The massive expansion in lithium mining around the world has brought up those who warn about the dangers, with the extreme edge of those warning suggesting that it could derail the switchover to electric cars, although that might well be coming from those with connections to the oil industry.

But it is a fact that many lithium compounds are alkaline, that soluble compounds can be naturally derived from the ores, and that lithium contamination of soils and water bodies would be a nuisance or danger. Basically any sort of problem you can imagine with sodium salts, the alkaline metal below lithium on the periodic table, would apply to lithium salts, so environmental contamination is not needed.

A major mine can control this with well-established procedures, and the inspectors from the Ministry of Mines and Mining Development can check very easily indeed. The same controls, and the same inspection, are close to impossible if the artisanal miners made any inroads into this sort of mining.

So for both economic and environmental concerns the export ban on ores and low-level processed products makes a lot of sense.

There are several steps in the processing, depending on how you want to store, transport and trade lithium. While for most metals the pure metal, in bars, is the ultimate goal, this is not really the case for lithium. Pure lithium is a dangerous and very reactive metal, bursting spontaneously into flame if it gets wet, oxidising fast in air, and generally having to be watched closely.

Pure lithium in the few cases where it is used, needs to be stored and transported in a batch of light oil, in a vacuum, or in a totally dry container of inert gases. It is that much of a nuisance.

Most lithium is transported, traded and delivered to factory gates of battery makers and other users as lithium carbonate, the traditional for trade, or increasingly lithium hydroxide, which is already rising rapidly in desirability and likely to dominate the market if, as is now predicted, the makers of the latest battery technology prefer this form.

While lithium hydroxide is a stable salt, it is not something you want to stick your hands into a bucket full of it. It is very caustic, like its sodium relative caustic soda. But we have been moving caustic soda around, and even selling it on supermarket shelves, for a very long time along with the caustic warning labels.

Apparently the growing demand for lithium hydroxide benefits the producers of lithium from hard rock, since it is easier to convert the lithium aluminium silicate salts into the hydroxide salt than the lithium chloride coming from the other main source, the brine pools. These pools are mostly in South America, in the area where Argentina, Chile and Bolivia meet, with Bolivia holding easily the largest reserves.

Brine mining involves pumping up the brine and letter it evaporate, for over a year, to concentrate the combination of sodium and lithium salts, along with other impurities, and then separating them out.

The ore ban can be modified if the Mines Minister agrees that a miner has a good case, but then the export tax, these days 15 percent since it is set within the tax law concerning VAT, kicks in. This is to allow underprocessed exports, but also to give the miner an incentive to process.

The Government does not always require the pure product. Chrome, for example, can be exported as ferrochrome with a set minimum chrome percentage rather than as pure chrome, but the product at this stage is bars of metal and not lumps of rock or finings, what is banned for export.

The other measure that the Government takes when setting the minimum processing standards, or allowing a miner with product under that standard to export while paying tax, is that concessions tend to be temporary. Good reasons to escape a ban, or have a standard set low enough to allow tax free exports, can result in less-than-desired processing of exports.

But generally the Government when renewing these lower standards or export-ban deferments, likes to hear what progress has been made and to see what special conditions might still apply. And even when people meet the old standard, there is often good reason why the standard might need continuous upgrading over time, if someone wants to at least escape export tax.

We have not yet had published the degree of lithium processing required to meet the export standard, or avoid the tax if a temporary permit is issued, but indications in the literature are that hard rock lithium comes out of a mine containing up to 1,5 percent lithium. Initial mine level processing can bring that to a far healthier 6 percent.

Those who find those figures low need to remember that lithium at the atomic level is the third lightest atom after hydrogen and helium, with just three protons and four neutrons in 92,5 percent of atoms and six in the rest, so its atomic weight is just under 7 on average. That means that in the most commonly traded compound, lithium carbonate, lithium is a little over 10 percent, and in the growing more desirable lithium hydroxide it is a little under 30 percent.

So the initial processing to concentrate the lithium fraction four or five fold could, if necessary, be a good place to start, but again wanting to see the chemical processing plants kicking in as soon as possible.

Zimbabwe has been mining lithium for around a century in Bikita, and Bikita Minerals is going strong and an external investor, Sinomine, is pumping around US$200 million into expanding the mine and starting the processing. We now have the Arcadia Prospect Resources opening next year, and further work is in progress in other sites from Shamva down deep into Manicaland.

This rapid growth in exploiting a major resource, to meet the vest fast acceleration in demand since the invention of the practical lithium ion batteries, may well make lithium one of the top metals mined in Zimbabwe, so fixing early in this acceleration the need for maximum processing before export is important.

When we just exporting modest quantities of petalite from Bikita to glass makers and a few other modest users, we might not have had to worry. Now we are going to be a major global supplier of hard rock lithium we have had to adjust our outlook.

At some stage, we need to keep moving up the ladder. While a battery maker might use pure lithium carbonate or lithium hydroxide as feed stock, more complex salts involving cobalt, manganese and phosphorous as well go into batteries. As with platinum, where the miners are looking at sharing a refinery, we can encourage the lithium miners to share a chemical processing plant, if no single mine has a large enough output to feed a viable plant, and if the investment needs more than one company.

The final stage is a battery factory, producing at least the most common types in the battery range the global market requires. This is high technology, and by that stage we will need a respectable chemical industry to be providing the feedstocks besides the metals that such a factory requires.

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