Our Services

EGi offer an integrated service in ARD and mine waste geochemistry including mine site geochemical investigation for ARD, metals, salinity, cyanide and other elements, preparation of sampling and testing programs, laboratory testing, material geochemical classification, ARD risk assessment and modelling, mine plan evaluation, operational audits and reviews, closure planning, ARD control and management plans, field trials, operational monitoring, training, and preparation and presentation of expert reports.

Site Investigation
EGi work with project personnel to develop site investigation and mine waste sampling programs.

Sample selection and preparation are critical phases of the overall mine waste geochemical assessment requiring geology, mine planning and geochemical inputs.

 

  

Laboratory Testing
As part of the integrated ARD consulting service provided to our clients, EGi maintains an in-house laboratory facility for specialised acid-base, net acid generation (NAG), acid neutralising capacity (ANC), and kinetic leach tests.  EGi co-ordinates routine analytical test work with outside commercial laboratories and is experienced with geochemical sampling and analytical requirements.

The methods and procedures developed by EGi are widely used throughout the mining industry for prediction and monitoring of acid drainage and identification of potentially acid forming mine waste materials.

 


Material Classification
Materials are classified according to the acid forming potential, risk of metal leaching, salinity and sodicity hazards, and possible toxicity due to metals, cyanide and other chemicals. For classifying the acid forming potential, EGi utilise NAPP (ABA) and NAG test results as initial screening tools.  Using these two independent measures significantly reduces the risk of prediction errors and better defines the ARD characteristics of samples.


ARD Risk Evaluation and Modeling
EGi utilise a range of in-house and commercially available empirical, mechanistic and geochemical models to assist in predicting project specific short term and longer term geochemical trends.(eg ARD Evolution diagram shown opposite).

 


Control and Mitigation Planning
A primary aim of EGiís approach is to provide practical operational specifications for the identification and management of mine waste materials to minimise the risk of operational and long ARD problems. Typical strategies include segregation, isolation, compaction, blending, limestone treatment, alkali material covers and engineered covers. EGi are experienced in working with geotechnical and engineering personnel to assist with the design and implementation of engineered covers. If treatment is required in the short or long term, EGi provide estimates of the likely ARD and metal loads and trends to assist engineers in the design of ARD treatment plants.


Training
Training site personnel is also a key component of EGi’s services. Solutions to ARD and mine waste geochemistry issues are multi-disciplinary and EGi offer introductory and site specific ARD workshops to increase site awareness and knowledge on ARD issues and controls.

EGi encourage and strongly support establishment of site-based testing programs and have extensive experience in setting up site programs throughout the Asia Pacific region.


Field Trials
Field trials scale-up the pre-mining laboratory studies and can also provide valuable insight into the performance of control strategies. In EGiís experience, field trials have also identified unexpected and unique mechanisms for ARD control (such as pyrite armouring and passivation) and provide excellent data to better predict the site specific time evolution of ARD.


Performance Evaluation and Operation Audit
EGi have 20 years experience on more than 250 mining operations world wide.  We have long term involvement at a number of large operations and work closely with operators in developing and evaluating practical and feasible ARD mitigation strategies.  We have extensive experience in conducting audits and reviews of ARD and mine site geochemical issues and are experienced in the presentation of reviews and evidence for company boards, governments, stakeholders, investors and planning tribunals.


Closure Planning and Monitoring
EGi are experienced with closure planning for historical mines, integrating closure needs into operating mines and planning for closure as part of new mine developments.

Understanding the long term geochemistry of mine waste and process chemicals is a critical part of closure planning.  A key objective is to identify and implement strategies that work with the material geochemistry to progressively reduce any post-closure liability.