Here is a full recap on the Advanced Material Project of Lynas and its attending management plan for the residues produced at LAMP . The proposed requirement of a PDF (Permanent Disposal Facility) and the recycling of LAMP's residues into industrial byproducts can be traced to events unfolding after the residents of Kuantan launched a big protest against the project. This rather long description will give you a holistic perspective on the controversy surrounding this rare earth project. It is written for the record and the benefit of all interested in the issue.
1. The Basis of Design for LAMP described in great details on the proposed Advanced Material Project of LAMP. The document concerned is marked as Document No. 4219298-000-GE-BD-001-0G.
2.'The project involves the development of a mine and concentrator plant in Western Australia and a processing plant in Malaysia which will produce high purity lanthanide compounds.'
3.'The Advanced Material Project will consist of two separating plants, each with a number of processing areas:
-Concentration plant , Mt Weld , Western Australia:
i) Crushing and grinding;
iii) Concentrate and handling;
iv) Water treatment and residue management; and
- Advance Materials Plant, Gebeng, Pahang, Malaysia:
b) Waste gas treatment;
c) leaching ( primary, secondary, tertiary);
d) Upstream extraction;
e) Downstream extraction;
f) Post treatment;
h) Water treatment and residue management; and
4. The design for the Advanced Materials Plant was first issued for client and internal review in March 2007. Originally the plant was to be sited in Telok Kalong Industrial park in Kemaman.
Before that Lynas actually planned to build the plant in Shandung Province , China. It was aborted because China imposed an export restriction on how the processed Rare Earth Oxides (REO) are to be marketed.
5. The design was formally approved by Lynas in March 2010. This timeline demonstrated a phenomena that the plant in Gebeng was constructed on an ongoing design and built platform. The construction started in 2007.
6. The Concentration plant at Mt Weld will produce intermediate Lanthanide Concentrate which will be the feedstock for the C&S ( Cracking and Separation) plant in Malaysia.
7.The C& S plant in Malaysia is known as Lynas Advanced Materials Plant or LAMP.
8. The LAMP is a chemical plant where the Lanthanide Concentrate will be treated in a chemical process that involves the use of very large quantities of acids and various other chemicals.
9.Briefly ,the Concentrate will be reacted with concentrated Sulphuric Acids in a rotary kiln followed by water leaching of the calcine and several subsequent stages of leaching, purification and solid liquid separation. Solvent extraction will be used to separate, purify and concentrate the lanthanide elements to produce a range of carbonate and oxide products.
10.Cracking of the lanthanide concentrate involves a process of treatment by concentrated sulphuric acid and thermal treatment just below its melting point. The process is known as 'Calcine or Calcination'. This process drives 99% of the Thorium content in the ore into the solid WLP residue.
11.33,000 tonnes of concentrate will be processed in each of the first two years of operation and subsequently 65,000 tonnes (dry mass). It is anticipated that in the each of the first two years of operation 11,000 tonnes of separated rare earth oxides will be produced and double that amount in subsequent years.
- Once the cracking is completed in the rotary kiln, the slurry of lanthanide-acid mixture goes through a 3 stage leaching process with clean water;
- After the primary leach the slurry will be filtered in 2 filter presses to enable solid-liquid separation;
- The primary filter cake is transferred to the second stage leaching and filtration. Filtrate from this stage will be recycled to the primary leach circuit and filter cake will be mixed with water for the third stage leaching.;
- The final solid residue from this leaching process is the Water Leached Purification (WLP) residues. They will be stored on site in the WLP storage cells (RSF).
Next comes the Extraction .....
- Extraction of various lanthanide compounds ( Rare Earth Elements) is accomplished with various solvents in 6 separate long solvent extraction (SX) circuits (trains) as shown below:
- SX1- SEG and HRE extraction;
- SX2- LCPN extraction;
-SX3- Iron removal
-SX5 -Didymium extraction
-SX6- Cerium extraction
- The water and extractants used each year will be as follows:
Water ;-1,605,625 tpa
(200,7 t/hr equivalent to 880 gallons per minute)
MgO :-11,605 tpa
P204:- 245 tpa;
N235 :- 8 tpa;
P507 : 83 tpa;
Kerosene :- 374 tpa
NaOH :- 32,585;
HCL : 65,747 tpa
Na2S :- 82 tpa;
Na2SO4 :- 47 tpa
BaCl2 301 tpa;
Oxalic Acid 4,400 tpa
Lime :- 1.190 tpa
- Most of these reagents (chemicals) are strangers to us but one thing is for sure they are used in such large quantities that all of the resultant byproducts will end up in our environment.
- With this 'heavy price' on our environmental , LAMP will produce the following REOs for sale in the international market : :
- SEG/HRE Carbonate 1,160 tpa
- LCPN Carbonate 5,400 tpa
- Lantunum Chloride, Carbonate, Oxide 2,800 tpa
- Lanthanum- Cerium Carbonate 8.200 tpa
- Cerium Chloride, Carbonate or Oxide 5,400 tpa
- Dydimium Oxide 5,600 tpa
- Neodymium Oxide 2,000 tpa
- Praseodymium Oxides 800 tpa
Total tpa REO 22,500
Post solvent extraction....
- The product solutions from the extraction plant will be channeled to a number of precipitation plants where the solutions will be neutalized, purified before precipitation as carbonate or for didymium an oxalate. The didymium will then be calcined at a temperature of 1000 degrees C to an oxalate.
- All post extraction processes include a hot water wash in its final stage. Thus the effluent discharged into our water pathway has a temperature higher than the ambient temperature!
- This concludes the processes that transformed Lathanide Concentrate into REO.
- Next we will take a look at the wastes produced and the proposed management by the party concerned.
Here are some of the definition of the abbreviations used in the last posting regarding the solvent extractions:
SX1 :-SEG and HRE extraction- Samarium, Europium, Gandolimium, Heavy Rare Earths ;
SX2- LCPN extraction - Lanthanum, Praseodymium, Cerium, Neodymium
All of the above are the various rare earths extracted in LAMP.