PROJECTS

Jiangsu Lithium Carbonate Plant (Zhangjiagang, China)

Background

Galaxy is developing a wholly owned battery grade lithium carbonate plant in China to maintain complete control over the production and quality of the Company’s products and to secure lower production costs. The main attributes of the location in China are a tighter supply chain and proximity to cement plants (residue disposal) and detergent plants for sales of sodium sulphate by-product. The plant will be operated by a wholly owned subsidiary of GXY that is a wholly foreign-owned enterprise in China. Production will use a well-proven production process that is enhanced through process automation and careful selection of high grade reagents. The plant will have capacity to produce 17,000tpa of lithium carbonate that is suitable for use in manufacturing battery cathode materials.

Plant Location

The Company’s lithium carbonate plant will be located in the Yangtze River International Chemical Industrial Park of the Zhangjiagang Free Trade Zone in the Jiangsu Province of China less than 1 hour northwest of Shanghai. The Company’s spodumene feed will be shipped from Esperance and unloaded at the Zhangjiagang port at a wharf that is less than 500m from the Lithium Carbonate Plant. The chemical park has in excess of 3,379 enterprises including 40 international companies such as Dow Chemical, Dow Corning, Chevron Philips, Dupont, Unocal, Wacker, Ineos, Asahi Kasei, Sumitomo, Mitsui Chemical and Vopak.

All the necessary infrastructure is available in the Yangtze River International Chemical Industrial Park.
Key utilities including water supply, sewage treatment, power supply, steam, telecommunications, industrial gas and fire-fighting facilities are available at the Company’s site. The location of the site that has been selected for the plant also provides access to supply of sulphuric acid, soda ash and caustic soda from neighbouring producers.

Lithium Carbonate Production

The following key process steps are involved in the conversion of spodumene to lithium carbonate:
• Decrepitation
• Sulphating roast and leaching
• Precipitation
• Lithium carbonate crystallisation
• Sodium Sulphate crystallisation

Feed Preparation

Decrepitation is essential for the hydrometallurgical processing of spodumene ore. Decrepitation in a rotary calcining kiln changes the crystal phase from the alpha to the beta form. This enables the lithium in the ore to be amenable to displacement by sodium. Moist spodumene concentrate averaging 6% Li₂O and 5% moisture is reclaimed from an open stockpile area and is fed to a rotary kiln. Decrepitation takes place at 1,070 °C – 1,090°C. The kiln product consists of a granular mix of beta-spodumene and unreacted gangue minerals, which upon leaving the kiln is cooled to about 100°C in a fluid bed cooler. The cooled kiln product is then milled in a dry grinding mill to reduce the material to below 200μm in preparation for the subsequent process step and pneumatically conveyed to a storage silo.

Flow Diagram – Jiangsu Lithium Carbonate Plant

Sulphating Roast

Dry, milled beta spodumene is thoroughly mixed with concentrated sulphuric acid in a pug mixer. The mixed material from the pug mixer is fed directly into the sulphating kiln and dry material exiting the sulphating kiln is gravity fed directly into the leach tank.

Leaching and Residue Removal

The solids from the sulphating kiln are leached in spent liquor and make up water. An optimal pulp density is maintained to maximise the lithium concentration at crystallisation as well as to ensure that the solubility limit of lithium sulphate during leaching is not exceeded. The lithium sulphate / residue slurry exiting the leach tank is pumped to a thickener and filter system to separate the gangue solids from the process liquor.

Precipitation

The precipitation circuit is designed to remove magnesium and calcium impurities from the lithium sulphate solution and present a clear filtrate to the lithium carbonate crystallisation stage. The process liquor is then passed through a media filter to polish the liquor stream.

Li₂CO₃ Crystallisation

Lithium carbonate is crystallised with the addition of soda ash and the increase in temperature of the system. The lithium carbonate slurry from the second crystalliser reports to the lithium thickener where the lithium carbonate crystals are allowed to settle to allow separation from the spent liquor.

Product Recovery and Packaging

The slurry containing the lithium carbonate crystals is filtered and the filter cake is dried in a rotary drum drier. The dried product is then conveyed to a storage silo in the bagging facility.

Sodium Sulphate (Na₂SO₄) Crystallisation

Sodium sulphate from the process solution is crystallised in an evaporative crystalliser system. The sodium sulphate slurry formed in the sulphate crystallisation stage reports to the sodium sulphate thickener where the solids are allowed to settle and then underflow to a vacuum belt filter. The sodium sulphate is sold as a by-product to the detergent industry.

Product Quality

Indicative Analysis

Chemical Content
Lithium	Li₂CO₃	>99.5%	Calcium	Ca	0.005%
Sodium	Na	0.025%	Potassium	K	0.001%
Iron	Fe	0.001%	Manganese	Mn	0.001%
Copper	Cu	0.001%	Silica	Si	0.005%
Magnesium	Mg	0.01%	Chloride	Cl	0.003%
Aluminium	Al	0.005%	Sulphate	SO₄	0.08%
Lead	Pb	0.001%	Moisture	H₂O	0.40%

Reagent Supply is Secured Locally

The key reagents for the sulphate process for lithium carbonate production are soda ash and sulphuric acid.
The Company signed a Letter of Intent (LOI) with its future neighbour, Two Lions (Zhangjiagang) Fine Chemicals Co., Ltd. to supply 38,000 tonnes of sulphuric acid per annum for 15 years. The supply arrangement also includes supply of sodium hydroxide and steam and access to modern automated bulk mineral unloading facilities.

Galaxy has also secured a supply of soda ash with the Jiangsu Huachang Chemical Co. Limited (Huachang). Huachang will supply 40,000 tonnes of soda ash (Na₂CO₃) per annum for 15 years.