Mud level gauge – advanced control and optimization of gravity settler operations
Our Mud Level Gauge takes frequent measurement of suspended solids throughout the depth of a tank e.g. thickeners, washers, settlers. This allows key aspects of a gravity settler to be controlled and optimized, including mud inventory levels and residence time, underflow density, flocculant usage and early detection of process upsets.
It is optimized for harsh environments, as it can provide accurate readings regardless of scale build-up or other fouling typical of these processes. It also has an automated washing mechanism and rich on-board diagnostics for minimal manual intervention and simple maintenance.
The Mud Level Gauge can also be used in other non-alumina settling tanks such as a tailings thickener, concentrate thickener or any counter current decanting circuit.
Clarity Meter – real time, high detail observations of process liquor clarity
In an industry first, our Clarity Meter provides reliable online measurement of fine suspended solids in process liquors in harsh operating environments. Through its frequent measurement of liquor clarity (1-5 minutes), the Clarity Meter identifies process upsets faster than alternative measurement methods, allows for advanced control and optimization of critical processes and enables consumable cost savings.
Its self-cleaning mechanism prevents scale build up or fouling that can accumulate within days or hours on a generic measurement instrument, preventing effective use. The overall instrument reliability is ensured by a patented design that prevents exposure of the valve control and secondary sensors to process liquor and corrosion resistant materials of construction. Along with on-board diagnostics and a clever integration of components, the maintenance workload is simple and minimal.
In our alumina refineries, we have seen significant value applying the Clarity Meter to mud thickener overflow, hydrate classifier overflow, filter feed and discharge and tray thickeners. It can also be applied in other operating environments where liquor clarity is important and where ordinary sensors suffer in harsh industrial settings.
Online Liquor Analyser (OLA) 2000 – frequent, automated measurement of major species concentrations in process liquor
Our OLA 2000 applies a patented method that measures the physical properties of Bayer process liquors (e.g. conductivity, density) that can be analyzed to determine the major chemical constituents of the liquor (alumina, total caustic, total alkalinity).
We have used the OLA in our operations for 20 years to control liquor concentration in locations including filtration feed and spent liquor digestion feed. Talk with us to learn how this can be applied outside of alumina refining.
Computational fluid dynamics – advanced modelling capability and expertise
We have used Computational Fluid Dynamics (CFD) modelling for the design and optimization of processing equipment within our global operations for nearly 30 years. Our deep understanding of the Bayer process and state-of-the-art computing hardware give us an edge in CFD modelling capabilities and capacity to provide insights for the alumina industry and analogous processes.
Our dedicated 224-core compute cluster and multiple software licenses exceeds the capacity of most external consulting firms and university engineering faculty facilities. This enables us to run simulations with fewer modelling simplifications and reduces the time to solution.
Our CFD modelling has enabled us to address and design for the following types of challenges:
- Erosion in slurry piping and fittings
- Flow distribution in piping headers
- Assessment of potential thermal damage
- Prediction of particle mixing and suspension rates
- Improving dust capture through improved gas distribution
Mercury – managing mercury emissions
We have developed measurement, control and storage methods and technology that have enabled us to reduce our mercury emissions by up to approximately 80 percent.
Our mercury offering consists of three components:
- Sampling and analysis of mercury levels in solid, liquid and gaseous streams across the refinery to develop a “mercury mass balance”
- Definition of proven and targeted solutions to reduce or control mercury emissions based on the plant’s mercury mass balance
- Advise on the best mercury collection, storage and disposal options to meet global EHS standards.
Mercury sampling is not straightforward, and we have developed adaptations to US Environmental Protection Agency methodologies to effectively measure mercury emission exits. The control strategies we have developed are more effective and lower cost than off-the-shelf mercury control solutions. This mercury control process has been successfully implemented at eight of our refineries globally.
BOD – biological oxalate destruction
We have developed a multi-award-winning biological process which destroys oxalate, which must be removed for effective alumina production. BOD is a more efficient and environmentally sustainable destruction method, with lower capital costs than alternatives such as residue storage or incineration.
The BOD process employs natural microorganisms to break down the oxalate and requires significantly less energy use and therefore produces lower greenhouse emissions.
Biological destruction is now the benchmark standard for oxalate disposal at our refineries. It has been implemented at four of our refineries with improvements to design and efficiency with each new facility.