Carlos Salinas, Lars Martinson, Ray Martinson and Paulo Eriz from our Santiago office and Mike Cook from the Denver office have written papers that will be presented at the TAILINGS 2018 seminar to be held in Santiago from 11 – 13 July 2018.
Three papers will be presented:
Hydraulic Scale Modelling Tests for a Tailings Transfer Box
Lars Martinson, Carlos Salinas and Ray Martinson
Paterson & Cooke, Chile
Theoretical and numerical approach to solve complex hydraulic problems has always been a useful tool to understand and obtain data to be used in the design of hydraulic structures, nevertheless, the use of computational resources limits its practical application in some cases, mainly because the complexity of the phenomena. Classical hydraulic modelling has proven its simplicity to show results in a physical and practical manner by testing multiple options reducing resources and providing excellent correlation for full scale scenarios.
In the case of the hydraulic behaviour of tailings transfer boxes, which are present in almost every mining operation, it can be complex and even more when considering the presence of high solids content, high throughput and high rheology slurries. The level of the behaviour understanding of non-Newtonian fluids and the prediction of how a transfer box will respond under certain conditions (flow rate, rheology, geometry, level, velocity) is a real hydraulic challenge and the proper representation and modelling of the phenomena can lead to improve the functionality of these type of important facilities.
This paper presents a case study in which a hydraulic scale model was designed and tested to verify the effectiveness of different modifications in an existing tailings transfer box. The most interesting aspects, challenges and results are described.
Gravity Tailings Distribution System: Analysis and Novel Presentation of Hydraulic Performance
Paulo Eriz, Carlos Salinas and Ray Martinson
Paterson & Cooke, Chile
Gravity flow tailings pipeline transportation systems take advantage of the elevation difference along the pipeline route to transport the tailings without adding extra energy into it. In Chile, due to local geography, several copper mining plants have tailings transportation systems operating by gravity.
Also, these plants process a large amount of mineral (over 100 ktpd) which results in the tailings storage facilities (TSF) footprint also being very large (10 to 20 km2, or more). Usually a large TSF has several pipelines, each one with multiple discharge points for operation. The operation of the system depends on the filling plan, solids content, location of the TSF’s reclaim water pond, availability of the distribution system pipeline, etc.
P&C Chile successfully evaluated the hydraulic behavior of an existing large gravitational transport system in northern Chile. The objective was to evaluate the transport capacities of the system pipelines considering the multiple parameters described previously.
To develop the analysis, the following steps were considered: laboratory test work including tailings rheology characterization and particle size distribution, flow and pressure data collection, hydraulic model preparation and calibration for a number of scenarios. This analysis resulted in a large amount of output data, which was difficult to directly interpret and not practical for operational purposes.
This paper, based on the study described previously, presents the general methodology used for the hydraulic modelling of a gravitational tailings transport and distribution system, with emphasis on the graphic tool that P&C developed to give the Client the capacity to use this information on the daily basis operation.
Simple Steps for Improving Your Thickener
Mike Cook1 and Lars Martinson2
- Paterson & Cooke Field Services, Golden, Colorado, U.S.A.
- Paterson & Cooke Chile, Santiago, Chile.
Mineral processing operations are continuously under pressure to increase tonnages, improve efficiencies and reduce operating costs. There is also considerable pressure to reduce environmental impact by recovering and recycling higher volumes of water within the plant. Most of the focus and effort is therefore naturally placed on production and the recovery process, where thickeners and in particular the tailings stream, are generally neglected and considered secondary to the process. This is true, until of course they fail to perform or end up shutting down the entire operation.
Incremental increases in tonnages or changes in feed characteristics over time often go unnoticed. The impact is sometimes recognized in the primary equipment, but it is usually disguised within the walls of the thickener. The industry is faced with a common challenge of how to increase the throughput, yet still maintain or possibly even improve the thickener performance. Common thickening improvements are typically reducing or eliminating the froth from the surface, increasing the underflow density, improving the overflow clarity, reducing the flocculant consumption, or increasing the volume of recovered water. Simple and proven steps are available to achieve these improvements and the cost is surprisingly low, especially considering the short payback period or when comparing it with the cost of a new thickener.
This paper highlights the key components within a thickener that can be upgraded, and the latest technologies that provide the greatest impact on the performance or accommodate changes in thickener duty. Some examples and results of successful upgrades are provided along with a description of what to upgrade, how to upgrade, and what the key benefits of upgrading actually are.
Find out more about TAILINGS 2018