Pressure oxidative leaching is a well-established technology that is used for processing base metal sulphides (e.g. nickel, copper and zinc) and for oxidising gold refractory ores and concentrates (as a pre-treatment for cyanidation). The technology is robust and reaction rates are fast. ALS offers a full range of pressure oxidative leaching services covering basic scoping tests, typically conducted at the bench scale, through to continuous pressure oxidative leach piloting for definitive feasibility studies.
ALS has created and invested in a 'state of the art' Hydrometallurgical Centre of Excellence (HCE) and has a dedicated fully equipped pressure leaching facility. HPOx testing utilises the same range of bench scale batch autoclaves as HPAL testing. These include:2 x 1 Gal Ti2 and 1 x 5 Gal Ti2, plus a 1 Gal Hastelloy batch autoclave.
Also available for continuous HPOx testing, and pressure oxidative flowsheet development, is a five compartment 25L Ti 7 submarine autoclave rated to 290°C. This smaller autoclave is integrated into the main pilot plant skids in parallel with the larger 90L HPAL unit.
The depth and breadth of the suite of technical services available to our experienced staff means that testwork is carried out efficiently and informed decisions can be made in a timely manner. We have access to expertise and developments at the cutting edge of metallurgical technology
We understand that metallurgical testwork is not a one size fits all or a pick off a menu proposition, and so we are happy to help walk you through the process. Or you might know exactly what you want and just need some clarifications.
No problem. Please contact us for further details.
This depends on the % solids selected, typically each 1 Gal leach will require between 0.3 kg to 1.0 kg of sample (DWE) ore and the extent of the program depends on the level of study being considered. For scoping tests a matrix of approximately 3 to 9 leaches is typical.
DWE refers to dry weight equivalent (DWE) and is typically quoted as the required sample mass without any moisture takin into consideration.
All bench scale autoclaves have controlled heating mantles and internal cooling coils to maintain accurate leach temperatures.
ALS have calibrated mass flow controllers on the oxygen feed lines and also measure the vent gas analysis for oxygen utilisation calculations.
Yes, ALS can offer a suite of kinetic samples typically taken at 5, 15, 30, 60 and 90 min intervals, however the maximum number depends on pulp density and starting mass.
Yes, ALS can offer sulphur speciation tests which are useful to control the extent of sulphur oxidation and elemental sulphur generated.
Generally, no. Insurance and safety protocols typically prevent renting laboratory space and this is not part of ALS’s business model. Clients are able to visit and witness testwork but this is to observe only! Typically clients may attend on 24/7 piloting campaigns and interact with senior staff members for Technical interactions.
Yes, Vendors often attend during specific bench and pilot scale testwork periods to conduct offline tests for filtration, flocculation and thickening on fresh samples from the testwork programs. This is common during 24/7 piloting campaigns.
Yes, clients are always welcome to visit our facilities and observe samples or tests in progress. Inductions are required and other rules may apply to visitors.
Yes, if a testwork program is in progress, ALS will happily dispatch testwork products and feed samples to vendors, third party laboratories, and customers as required. Fees apply.
Yes, piloting testwork follows a successful bench testwork program where the proposed process flowsheet has been selected. Continuous testwork will prove the viability of the selected flowsheet and confirm recycle streams and overall circuit kinetics which is not possible from only batch or bench scale tests.
No, as it is not our core business and would put us in direct competition with many of our clients. We can, however, put you in contact with a range of reputable engineering providers and consultants.
Leach testwork rarely happens in isolation and typically many other processes are required pre and post leaching testwork, as follows: Sample Characterization, Mineralogy, rheology, solid liquid separation including flocculation and settling, impurity removal, Iron control chemistry, tailings management, materials of construction selection testwork (corrosion coupons) preliminary piloting and fully integrated piloting
Click on the above links or contact us for further information. We can integrate a full program for you if required.