Cobre del Mayo mine chooses Alia
January 2016
Flow Measurement & Control
By Peter Baker, Ivy Automation.
Copper use and extraction has been in existence since 6000 BC. However, as “pure” copper (80-100%) became scarcer as in-ground pure deposits were used up, smelting and leaching of copper ore became the methods of copper production. Due to the concentrations of copper in the mined ores and the pollution concerns surrounding smelting, copper heap leaching has evolved to the point where today, using the “Electrowinning” process, mined ore concentrations of 0,3 to 2,0% can be converted into pure copper directly. The heap leach process covers a very large expanse of land and the continuous production time is months and years.
In the heap leach mining procedure there is a maxim, “We don’t get it if we don’t wet it”, and this is exactly what the mine operation focuses on as detailed below.
The ore is carefully extracted, crushed and spread – to a depth of 10 metres – over an environmentally contained area of some 100 000 square metres. The crushed ore is then evenly irrigated with a sulphuric acid solution to dissolve the copper from the ore for eventual collection at cathodes located within the field. The distribution or percolation of the acid through the ore is done through 300 mm PVC feeder pipes that are laid the length of the field, with smaller distribution lines branching off of the main line. The distribution lines are laid parallel and equally spaced to ensure proper dissemination of the acid throughout the field. This is where measuring the acid’s flow rate becomes critical. Too high a flow and the acid will form a “tunnel” through the ore instead of distributing evenly and “wetting” all the ore. Too low a flow, and the process becomes excessively time consuming and uneconomical. Therefore, it is important to select a flow metering technology that can meet or exceed the metering requirement, and be economical.
Cobre del Mayo
In this operation, the flow measuring devices chosen were Alia battery operated electro-magnetic flowmeters (magmeters). A battery operated magmeter was selected because of its high accuracy, wide turn-down ratio, low maintenance life cycle, long field life and ease of installation (no external power supply line required).
The sensor housing and process connections are constructed of 316 stainless steel for corrosion resistance. The inside of the sensor is PTFE lined with Hastelloy ‘C’ measuring electrodes. Due to the fact that the actual pipe is non-conductive CPVC, and the sensor requires grounding contact with the process, the sensor included an integrally mounted earthing electrode to ensure faultless measurement continuity. (FYI – 90% of magmeter problems can usually be traced to grounding/earthing problems.)
The transmitter, similarly having no corrosive carbon steel components, is remotely mounted and battery powered. It can be configured for power saving by only transmitting the flow rate when it changes by a predetermined operational margin. The transmitter’s internal RS-485 output was then connected to a solar powered IEEE 802.11 local wireless network transmitter, which broadcasts the flow signal to a central control room where it is monitored.
In summary, the Cobre del Mayo mine is a successful operation producing 99,9% pure copper. It is expanding the measurement and control network throughout its operation, because as the instrumentation maxim goes: “One cannot effectively control or manage a process which is not accurately and reliably measured”.
For more information contact Martin McLeman, Blanes Pressure Solutions, +27 (0)11 422 1749, martin@pressuresolutions.co.za, www.pressuresolutions.co.za
Further reading:
Ultra-compact mass flow meters with advanced transmitters
Emerson Automation Solutions
Flow Measurement & Control
Emerson has introduced the Micro Motion G-Series line of Coriolis mass flow and density meters, the most compact dual-tube Coriolis mass flow meters on the market. They offer the same level of quality and reliability as standard designs, but in a much smaller and lighter form factor.
Read more...
Flow measurement transmitters with IO-link interface
Senseca
Flow Measurement & Control
Senseca has introduced the enhanced OMNIPLUS range of transmitters that feature an intelligent IO-Link interface.
Read more...
Optimisation of alkaline electrolysers
Samson Controls
Flow Measurement & Control
his application study relates to the use of a smart meter valve in alkaline electrolysers, and is based on proven experience with one of the biggest hydrogen electrolyser producers in the world. The project proves that the smart meter valve’s added functionality creates an ideal setup in alkaline electrolysers for reducing cost and improving functionality and system performance.
Read more...
Preventing spills and improving operational efficiency
Flow Measurement & Control
In an industry where every spill carries a hefty price tag, Point Energy Partners found that the manual and low-tech systems at their saltwater disposal sites were a significant problem.
Read more...
Accurate flowmeter for oil & gas
Endress+Hauser South Africa
Flow Measurement & Control
Promass Q, the high-tech Coriolis flowmeter from Endress+Hauser, is now also available for larger pipe sizes with maximum flow rates between 850 and 2400 tph.
Read more...
Optimising CIP processes with precision instrumentation
Endress+Hauser South Africa
Flow Measurement & Control
Many food and beverage manufacturers encounter challenges with CIP processes that take too long. Have you considered exploring potential solutions to address these issues?
Read more...
How predictive maintenance will help tackle water scarcity
ABB South Africa
Flow Measurement & Control
The water industry is facing increasing pressure to optimise treatment processes and address the impending global water crisis. ABB’s global product line manager, Krishna Prashanth suggests how the integration of smart instrumentation and predictive maintenance can ensure the highest quality treatment of water.
Read more...
Flowmeters with faster and more reliable data transmission
ABB South Africa
Flow Measurement & Control
ABB has launched the CoriolisMaster and ProcessMaster flowmeters, which can be powered over the same Ethernet cable used for data transmission, eliminating the need for separate cabling.
Read more...
Ice cold optimisation
Turck Banner Southern Africa
Flow Measurement & Control
A well-known industrial company in China specialises in the research, development and production of high-tech materials and special industrial furnaces for various fields and applications. To ensure the safe and efficient operation of the furnaces, the flow and temperature of the cooling water and the energy consumption must be constantly monitored and controlled. Turck’s FS+ flow sensors are ideal for this application as they can monitor the temperature of the cooling medium in addition to the flow.
Read more...
How wet steam undermines boiler efficiency
Endress+Hauser South Africa
Flow Measurement & Control
The Endress+Hauser team understands the daily challenges and demands placed upon energy and utility managers across the spectrum of steam generation, distribution and consumption activities. Its global team is committed to working with its partners to overcome these complexities and particularly those that challenge a safe, economic and sustainable source of steam energy production and delivery.
Read more...
printer friendly version