Did someone mention pure DMS?????, without flotation? Let alone flotation only
An interesting guy to follow on X. The poor bastards are going to be shitting bricks when AVZ is running up the hill (Kate Bush)
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If a spodumene lithium miner can produce an SC6 product using DMS (dense media separation) with high recoveries, its the next best thing to having a money printer.
So why does a company such as $PLS need to use a combination of both DMS + Flotation? You'll probably need to understand some basics about DMS first.
DMS is a very simple processing technique. It essentially separates minerals based on their density. Some typical densities for different minerals:
Quartz - 2.64 g/cm3
Feldspar - 2.58 g/cm3
Spodumene - 3.11 g/cm3
Iron Oxide - 5.24 g/cm3
The ore is first crushed to help liberate the spodumene from the other minerals. The ore is then placed into a DMS cyclone along with a HLS (heavy Liquid separation). The HLS generally has a density of 2.9g/cm3, slightly below the mineral you want to extract. The cyclone spins, the lighter minerals "float" through the HLS and the heavier minerals "sink" through it. Simple process! See below for a typical DMS.
That's why larger crystal sizes for spodumene are better, because they can be liberated (separated) from the waste materials with less crushing. Finer crystals are generally harder to separate from the junk material. They generally need to be crushed to powder in a ball mill and sent to flotation.
The main issue occurs when the spodumene can't be liberated from the junk (industry uses the term gangue) and if you imagine, if a sample is half spodumene and half feldspar, the new density will be (3.11+2.58)/2= 2.84g/cm3. So this will just float out with the junk and your recoveries will be bad!
4 products generally come out of a DMS.
1. A high grade spodumene concentrate
2. A low grade, waste product (lots of quartz and feldspar).
3. An intermediate product that contains composites of spodumene and waste.
4. Ore too small to be treated by DMS.
It is my understanding that $PLS introduced flotation to deal with points 3 and 4 above. Also, one of my previous posts I mentioned how $PLS purchased Altura Mining whose ore was quite coarse. They blend this ore with their own to improve the overall consistency of the feed grade.
$PLS are a well oiled machine with their processing. It will be interesting to see how companies such as $LTR go with pure flotation when they commission.
Ever wondered why some lithium hard rock companies are producing SC6 and others a product containing less lithium (SC5.5, etc.)? Here's why whilst I sip my morning coffee (the crema is amazing today). $PLS - SC5.5 $AKE - SC5.3 $MIN - SC6.0 First, understand that there are specifications set by converters that spodumene hard rock producers need to meet depending on how their product is graded. There are two main grades of spodumene concentrate: 1.) Chemical 2.) Technical A lot of people don't realise this but technical grade concentrate is more strict than chemical. Funnily enough, technical grade is used in glass and ceramics, and chemical is used for battery applications. I believe the current specifications (what is preferred by converters) for each grade are as follows: Chemical - (<0.8% Fe2O3, SC5.0-SC6.0) Technical - (0.15% to 0.5% Fe2O3, >SC6.5) Fe2O3 is iron oxide Li2O is lithium oxide It really is a balancing act between the recovery rates and meeting the above specifications. You could produce SC6 but if your waste content (iron, mica, etc.) is high, your recoveries are going to fall through the floor. Example: Say you've got a deposit that's li2O is 1.0%, 1.2% Fe2O3, a recovery rate of 75%. If you want to get SC6 and meet the specifications, you're going to need 8 tonnes of ore and you're going to have to deal with 9.6% Fe2O3!! An expensive process. Compare that with a company that has 1.5% li2O, 0.6% Fe2O3 and a recovery rate of 75%. They need 5.3 tonnes of ore to achieve SC6 and only have to deal with 3.2% Fe2O3... So companies will produce a product that gives them the most volume whilst still meeting the specifications. I should add that converters can still accept ore outside of these specs, but the high iron content will produce "clinkers" when they roast the spod at 1080degrees (a step in converting to hydroxide) which are difficult and costly to remove. Summary: Waste content (iron, mica, etc.) is extremely important for lithium miners! Make sure you study the met work before investing. No two deposits are equal.
Off to exchange library books at the old school house for a few hours - actually, for Friday night drinks with the locals. Don't taunt me with shit later tonight
Great post, very informative!