Halland Instruments AS

pH and sedimentation rate analyzers for the zinc industry.

For application examples (installations) in the stages of the zinc process, click on the navigation bar above.

Applications in other
industries:

The PH-1400 pH analyzer:

The “PH-1400”, the pH analyzer for pH control of the processes in the hydrometallurgical zinc industry.

The neutralization process and the jarosite process are impossible to control with accuracy with conventional pH analyzers.
In the hydrometallurgical zinc industry the temperatures are high, the solids content are high and the solutions are complex with high ionic strength. Accurate pH measurements are very important in the processing of zinc concentrate. Accurate pH measurements increases the production capacity, reduces the energy costs, increases the yield and reduces the overdosing of the additives.
The problem is that other pH measuring systems have low accuracy and short lifetime of the electrodes.
The main causes of the problems are poisoning of the reference electrode and build-up of a layer of coating from the neutralization or precipitation process on the pH electrode.
Our PH-1400 analyzer has high accuracy and the lifetime of the electrodes are very long, many months or even years. The reference electrode is never poisoned and the pH electrode surface is kept clean by an advanced cleaning system.
Other systems require frequent calibrations, however, this only disguise the problem, the problem of low accuracy persists. A short lifetime of the electrodes or combination electrode is a symptom of low average accuracy, making process optimization impossible. Systems with retractable electrodes have low accuracy, the lifetime of the electrodes are short, the lifetime of the mechanic system is short - reliability is a problem, and it is cumbersome to calibrate the measurements.

The following properties distinguish our analyzer from other known technology:
1. Most reliable, infrequent error with the analyzer or the electrodes, very low-maintenance.
2. High short-term and long-term accuracy.
3. Very long life of the electrodes, it is not possible to get high long-term accuracy without long electrode life.
4. Other systems require calibration daily or even several times daily to provide high accuracy. Our analyzer gives high accuracy even with weeks’ interval between calibrations.
5. It is fast and easy to calibrate the analyzer, there is no sample head which must be dismantled for calibration.
6. It is easy to install the analyzer and normally no encroachment in the process equipment is needed.

The ASRM-1300 automatic sedimentation rate measuring station:

Modes of operation:

• Normal: The instrument is running continuously.
• For batch processes: A Modbus start command or a 24 volt signal starts the analysers and the analyser runs continuously until a stop command or a 0 volt signal is received, then the current cycle is finished, and the analyser stops.
• Fixed intervals; the instrument executes one cycle for instance every 10 minutes.

“ASRM-1300”, the  automatic on-line sedimentation rate meter.
This analyzer is installed before the neutral thickeners, it is of great help for the running of this process stage, a must!
The ASRM-1300 measures the time required for the sample to become clear or translucent, down to a fixed (adjustable) distance beneath the surface.
Function:
The instrument sucks a sample from the process, to a measuring cell (cylinder), where the required time for settling is measured. The sample is then returned to the process. Then the instrument sucks up a dose of detergent, for instance an acid, from a container and sprays the detergent into the cylinder. The cylinder is then washed with water, and the cycle is repeated. The frequency of washing with detergent is programmable. The instrument gives you a unique possibility for process optimizing, because it measures the response to changes in settling properties so rapidly and automatically. A manual sample is not the same, it is not possible to replicate an automatic measurement because the manual measurement is depending of how accurate the operator is.
This is truly an early warning system for any oncoming process difficulties. The instrument is a complete-working unit for sampling, measuring and washing of the cell. It has 4-20 mA output and Modbus RTU computer interface.
The sample is usually taken from a tank, launder or pipe, before the thickener or filtration station, but after the addition of flocculant, if used.