Site operations and closure services from ECBH – helping you operate efficiently and economically, and meet regulatory requirements.
Mining Site Operations and Closure
ECBH understands you need a reliable, cost effective method to treat metal contaminated wastewaters and effluents to meet local regulatory requirements.
Our High Density Sludge (HDS) experts have designed, engineered and commissioned such plants since 1998 and have delivered many quality HDS solutions. Let’s work together to ensure your site uses responsible and sustainable water treatment solutions.
HDS technology is beneficial to operations that produce solutions high in sulfate ions as a result of pressure oxidation or bio-oxidation. Our HDS process effectively removes base metals as stable precipitates by forming calcium precipitates. Iron co-precipitates on the surfaces of recycled sludge particles.
In the HDS process, limestone/lime and recycled sludge are added to the lime-sludge mix tank at the beginning of the process. This becomes the main neutralization agent. This mixture is discharged to a rapid mix tank where it is mixed with incoming solutions, thereby achieving neutralization. This mixture is fed to the main lime reactor where a combination of aggressive aeration and high shear agitation ensures optimum process chemistry and clarifier performance. The discharge from the lime reactor is then treated with flocculent. The clarifier separates the treated effluent from the sludge and a portion is recycled back to the start of the process.
The HDS process is a proven, robust technology that uses standard equipment. It has many advantages over other lime precipitation systems for metal removal.
These include:
- A substantial reduction in sludge volume that results from an increase in sludge density. An increase from 2% to 30% solids reduces the volume of sludge by over 95%
- Lower sludge disposal costs
- Increased chemical and physical sludge stability. Within several days of deposition, the sludge drains so that it consists of more than 50% solids. These solids are stable enough to support the weight of people walking on the impoundment area
- Long-term effectiveness. Following 15 years of HDS use at one facility, there has been no contamination of the surrounding groundwater
- Production of a high quality effluent that can meet local regulatory constraints
- Easy automation
ECBH will make certain that all factors affecting your HDS project are considered, and will ensure that the design and construction of your project meets all regulatory and environmental guidelines. Our top priority is to help you affordably and effectively comply with environmental discharge limits. Partner with us and let our team of HDS experts help you manage your wastewater stream.
The first step in preventing or removing acid rock drainage problems is to identify the acid generating or neutralizing minerals that may cause or mitigate acid rock drainage (ARD).
ECBH’s High Definition Mineralogy team has the expertise to address these points and provide you with objective, robust data you need to proactively manage this important environmental issue.
ECBH experts use environmental mineralogy to characterize acid generating minerals or phases to:
- Determine the potential for future contamination
- Develop remediation plans including the treatment and processing of products and waste material
- Establish methods to control the redistribution of acid generating or acid neutralizing minerals in the environment
- Create monitoring systems to ensure ongoing compliance
The characterization of the acid-generation potential of ores is a vital component in the management of ARD and the prevention of long-term environmental liabilities. ECBH can perform a full mineralogical characterization of rocks, ore and tailings to determine their acid generating or acid neutralizing potential. From such characterizations, acid generating minerals (e.g. pyrite, marcasite, pyrrhotite) and acid neutralizing minerals (e.g. calcite, dolomite) are quantified.
The ratio of these acid generating or neutralizing minerals and their locked or liberation characteristics will determine if a sample will be a net acid generator, thus assisting with environmental planning, closure planning, and rehabilitation projects. This type of fundamental data can then be used to determine project costs.
We provide comprehensive laboratory analysis, including the modified Acid Base Accounting test (ABA), for the characterization of Acid Rock Drainage (ARD).
The modified ABA test helps determine the propensity of the tailings/waste rock to generate acidic conditions and provides input parameters for kinetic tests.
The ABA test provides quantification of the:
- Total sulfur, sulfide sulfur, and sulfate concentrations present
- Potential acid generation (AP) related to the oxidation of the sulfide sulfur concentration
- Neutralization potential (NP) of the sample
If necessary, a correction for siderite can be made to oxidize the ferrous iron prior to NP determination. Carbonate concentrations are analyzed and carbonate NP values can be determined. The balance between the AP and NP assists in defining the potential of the sample to generate acid drainage.
ECBH’s qualified staff operate in laboratories with state-of-the-art instrumentation, using industry best practices. We have the technical expertise to provide mitigating strategies and innovative, yet practical solutions to reduce the environmental impact of your operation.
ECBH laboratories are staffed by professionals with extensive experience in the minerals sector. We understand why you need to mitigate Acid Rock Drainage (ARD) and can provide you with extensive analytical testing options including the Static Net Acid Generation (NAG) Procedure.
Net acid generation (NAG) testing determines the balance between the acid producing and acid consuming components of tailings/waste rock samples. NAG results provide the acid rock drainage characteristics based on the complete oxidation of the sample’s sulfide content (as well as ferrous iron from siderite dissolution). Acid that is produced by oxidation is consumed by carbonates and/or other acid consuming components of the material. The pH of the solution is measured (NAG pH). The acid remaining after the reaction is titrated with standardized NaOH to determine the net acid generated.
Samples that have high sulfide contents may need more than a single aliquot of hydrogen peroxide to ensure complete oxidation of all the sulfides present. At the end of each stage, the sample is filtered to separate the solids from the NAG solution. The NAG solution is then assayed for pH and acidity, while the solids are recovered for repeat oxidation using another aliquot of hydrogen peroxide. The total NAG capacity of the sample is determined by summing the individual acid capacities from each stage.
ECBH provides you with the systematic characterization of the acid producing potential of your ores. Partner with us to get confidence in your ARD program and prevent long-term environmental liabilities.
Most mining legislation states that cyanide-rich plant tailings must be oxidized before being deposited into tailing ponds. An operational flowsheet using a proven treatment technology is required by most financial institutions prior to investment.
ECBH offers a number of cyanide destruction processes. The SO2 air process is relatively simple and invariably cost-effective. During the process, sulfite ions react with atmospheric oxygen and a copper catalyst as follows:
2CN- + Na2S2O5 + 2O2 + 2OH- --> 2CNO- + Na2SO4 + SO42- + H2O
The SO2 process offers a number of advantages over other cyanide destruction methods including:
- Low reagent cost
- Efficient oxidization of CN WAD (weak-acid dissociable cyanide)
- The possibility of using sulfite salts and zinc sulfate during the process
ECBH can review your flowsheet at both the batch and pilot scale and assess if the SO2 air process is appropriate for your project or mine. The batch test allows our metallurgists to carefully monitor the CNWAD concentrations and establish the target conditions (catalyst, oxygen, redox potential) for continuous pilot testing. Data from these is used to design a flowsheet and set parameters resulting in compliant cyanide concentrations in your tailings at the lowest possible cost. Our pilot testing will demonstrate this for all stakeholders.
ECBH has the robust technology and technical expertise to provide you with bankable and effective cyanide management at every stage of your gold recovery operation. Contact us early in the planning stages of your project to learn if the SO2 air process is the best solution for destroying the cyanide used in your operations.
Hydraulic conductivity is the rate at which water moves through soil or porous rock.
This information is crucial for a wide range of industries as it can have a major impact on the structure and stability of buildings, mines, bridges, landfill sites, tailings ponds or other infrastructure.
ECBH can provide independent, industry standard soil testing, including hydraulic conductivity. Results of our hydraulic conductivity tests help you to mitigate your risk by assessing conditions such as erosion or structural constraints that may affect your project. Depending on your project, we can also provide a fully integrated package of related tests including:
- Acid rock drainage testing
- Rheology testing
- Geochemical studies
- Groundwater and hydrogeological studies
- Environmental and social impact studies
ECBH teams of hydrogeologists are backed by a global network of laboratories with standard methods and consistently reliable quality. These professionals determine the hydraulic conductivity of your soil and consider both the density and the kinematic velocity of the water. Spearman’s rho cell coefficient can also be applied to evaluate the dependence between variables in the data. Our fully-equipped laboratories, precisely calibrated equipment and transparent, 3rd party approach ensures accurate, unbiased test results.
ECBH has earned a reputation for ethical testing practices, high-quality analysis procedures and strict conformance to industry standards. Trust the experts when you need to be sure of the hydraulic conductivity of the soil or rock at your site.
Pavement engineering services from ECBH – ensures the quality and extends the lifetime of your pavement systems through effective testing, design, construction and maintenance.
Whether you are designing, constructing or maintaining streets or highways, you need to ensure the quality and sustainability of your pavement systems. Our pavement engineering services offer you specialized testing, design, construction and pavement maintenance to ensure quality and extend the lifecycle of your systems.
WHY USE PAVEMENT ENGINEERING FROM ECBH?
Whether it is a new construction or pavement maintenance project, we can help you:
- Ensure the quality and sustainability of your pavement systems
- Avoid disastrous consequences from discontinuities, cracks or low skid resistance by implementing the correct design and materials
- Design and maintain flexible and rigid pavements – including streets and highways – through our advanced pavement engineering techniques
TRUSTED PAVEMENT ENGINEERING
We specialize in the evaluation, design, implementation and maintenance of pavement, asphalt and concrete surfaces. As a result we offer you unrivaled technical expertise, experience and a unique global network capable of serving you wherever your operations are based. Plus, our comprehensive technical accreditations and highly qualified experts ensure that your projects are carried out thoroughly and accurately.
Our pavement engineering services include:
- Concrete durability evaluation
- Concrete mix design
- Contract works
- Evaluation of in-situ and laboratory stabilized products
- Investigation of materials for road construction
- Pavement design of roads
- Pavement maintenance
- Pavement management system (PMS)
- Pull-off testing
- Relative humidity assessment of concrete floors
- Shotcrete round panel testing and technical support
- Slip/skid resistance assessment of pedestrian floors and traffic surfaces
- Testing of existing pavements
- Thermal resistance of sand for high KV cables
Contact us today to find out how our pavement engineering services can ensure the quality and extend the lifetime of your pavement systems.
Our automated laboratories offer complete static and kinetic ARD testing services, with highly trained professionals following fixed testing protocols to ensure reproducible results.
Humidity cell tests are designed to mimic weathering at the laboratory scale in a controlled fashion. The test determines the rate of acid generation, the variation over time in leachate water quality and thus allows you to develop mitigating strategies.
The standard humidity cell test is conducted at the bench scale. The sample is subjected to alternating cycles of dry and moist air to simulate precipitation cycles. The sample is soaked for a specific length of time with deionized water. The water percolates through the sample and is then collected. This leachate is analyzed for a number of parameters including pH, sulfate, acidity, alkalinity, conductivity and metals (including Ca and Mg). The test design can be customized to better account for sample matrix effects by increasing or reducing the particle grain size or altering the shape of the cell and changing the flow rate.
Larger scale cells can test several parameters. The response of coarser samples more typical of waste rock can be assessed. Various cover design options can be tested and the effectiveness of cover systems in reducing ARD can be assessed.
Other humidity cell design options that ECBH can support include the addition of bacteria, flooding of the sample, temperature cycling, variation of the humid-dry air cycle, and variable duration of the air/leach cycle. Depending on your circumstances, we can design a testing program to truly reflect your operational site.
Humidity cells test results are reviewed monthly to check progress and determine if extended leaching is required. Tests typically run from 16 to 24 weeks. Tests of longer duration are run to evaluate ARD control options. Such tests are designed to provide data for mitigation strategies, thus lessening the effects of ARD. ARD reactions are complex and ECBH has the technical expertise to help you with the interpretation of your results.
As the ARD generating and neutralizing minerals leach away, the mineralogy of the leach sample will change. ECBH’s high definition mineralogy services provide characterization and documentation of these changes throughout the duration of the test. The integration of our environmental mineralogy expertise gives you a more complete picture of the mineralogical causes of ARD potential and neutralization strategies.
Soil and groundwater pollution can become an environment and health problem that far exceeds the boundaries of your site. Avoid environmental disasters and the financial consequences with a pollution study from ECBH.
With our international experience in environmental management, we have the track record to deal with your ground contamination management.
We use state-of-the-art equipment to conduct manual or mechanical drilling and take soil and water samples for analysis. Our scientific professionals use our certified laboratories and on-site mobile installations to investigate a range of parameters to understand what pollution is present.
Our experienced team of geologists, hydrogeologists and agronomists use the latest safety equipment and top-of-the-range equipment to carry out technical investigations of groundwater and soil problems – from simple sampling to deep drilling and installation of wells and piezometers. Our range of techniques include:
- Installing piezometers to monitor groundwater contamination
- In-depth characterization study to determine the extent of pollutants
- Groundwater modeling to examine the dispersion of underground contaminants
- Sampling of surface waters to determine pollutant levels
- Analysis of weather data to anticipate fluctuating temperatures and potential rainfall that can contribute to the release of contaminants
- Air and odor measurements
- Membrane interface probe (MIP)
- Passive soil gas sampling modules (Sorbers)
- Frost
- Direct well
Through our pollution studies, we will provide you with the independent advice your company needs to meet all regulatory requirements. We work with you to develop a successful environmental management program and a cost-effective plan for site decontamination.
Our expertise in contaminated land studies includes the following fields:
- Historical study
- Orientation ‘first step’ study
- Characterization or delineation study
- Brownfield analysis
- Contaminant fate and transport study
- Excavated ground management
- Feasibility study
- Remediation study
With proven experience and an international network that guarantees you a quality service throughout the world, we will tackle your ground and groundwater contamination problem rapidly and efficiently. To protect your site and avoid costly retroactive clean-up activity, call our contaminated land experts today.
For safe and legal disposal of contaminated soil, contact ECBH for our expert excavated ground management services.
During engineering works, demolition or the construction of new buildings, the resulting excavated ground needs to be managed and disposed of. This can be complex, as often this ground is contaminated due to previous industrial use of the land.
Our excavated ground management team can offer you the expertise you need.
We provide technical and scientific assistance, taking soil samples on-site, based on the excavation depth and volume. Analysis in our certified laboratories provides us with the results needed to assess the site and recommend the best techniques to remove or assign a value to, or valorize the excavated ground. Valorization makes it possible to remove surplus ground at the lowest cost and with respect to relevant legislation.
We ensure that your site is meeting all necessary regulatory requirements for safe disposal of the excavated ground and provide administrative assistance with the required documentation.
Contact us today to find out more about implementing an excavated materials management plan to specifically suit your site needs.
A waste water treatment study from ECBH ensures that waste water is able to be safely disposed of or recycled for reuse in your operations.
To prevent environmental pollution, it is essential to properly treat waste water before it is discharged into the sea, rivers or streams. The purification of waste water can mean safe disposal in compliance with regulations. Also, suitably treated waste water can be recycled and reused for irrigation and other high-quality water purposes. To meet all necessary water regulations in either of these cases, you can rely on our waste water purification services.
We are your best choice for independent and reliable inspection, verification, testing and certification. Our extensive experience with worldwide water agencies will ensure the success of your waste water purification project.
Whether you have a new treatment plant or an existing installation, we can look at new treatment innovations and improvements that can make a difference, such as aeration systems and disinfection treatment. We can also extend and enhance your existing operations with minimum disruption to your current business.
If you are operating your own self-monitoring system, our environmental teams can quality control and validate your water monitoring and sampling devices. Our checks include:
- Reviewing the methods used for water sample collection
- The placement and operating conditions of your sampling and monitoring devices
- Sampling volumes
- Temperature levels
- Transport and storage conditions for water samples
- Annual check of all self-monitoring data transmitted during the year
We validate your compliance to technical requirements such as:
- Verification of systems checks
- Assessment of the quality of evaluation devices and sensors
- Organization of samples
- Measurement controls
- Cleanliness and level of silting
ECBH has developed new technology to assess the biological content of your waters by using the innovative technology of Adenosine Triphosphate (ATP)-metry. ATP-metry is a fast and cheap quantitative method that will help you efficiently audit your treatment process and identify the needed improvements. We are the only company able to provide this second-generation ATP-metry on a global level.
Our accredited, multidisciplinary team of experts will ensure your compliance with all relevant regulations. We also provide technical advice and information at all stages of your project to ensure success. Call our experienced environmental team for your waste water treatment study today.
The Toxicity Characteristic Leaching Procedure (TCLP) determines the mobility of inorganic contaminants present in a sample and whether the leachates generated would classify the material as "hazardous". The leachant is determined based on the acid neutralization capacity of the sample material. The selected leachant is added to the sample at a 20:1 liquid-to-solids ratio and the sample container is rotated end over end for 18 hours. The resultant slurry is then filtered through a 0.7 µm glass fiber filter and analyzed for total metals.
Partner with us to be confident that you completely understand the scope of your ARD situation.
