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pH probe for Flotation Circuit (1 reply)

1 month ago
Obergruppenfuhrer 1 month ago

What do you recommend as a pH probe to measure pH in cyclone overflow tubs and in flotation cells. I have used Foxboro's but they drift within 2-3 days and once this drift occurs the measurement of high pH (>11) becomes problematic and have to be re-calibrated frequently. The pH probes are not always submerged in pulp (if the plant is down for a couple of hours) and I am not sure if this is contributing to the drift when the probe dries out. What is is good pH probe manufacturer that would not suffer from substantial drift? Any tips for avoiding pH probe drift?

Bill Rico
1 month ago
Bill Rico 1 month ago


We recalibrate our pH probes once a week but we have a cleaning routine that varies depending on probe location. Cleaning occurs because we have some deposition which affects readings. Some probes we clean once a week some we clean every 3 days. Our "normal pH" readings are on the 9 to 11 range depending on the flotation stage. Our probes are always submerged in slurry, unless plant is down which is not frequent.

I think that with all pH probes, no matter the brands (bench scale and in-stream), is that when a bulb dries out, it must be re-calibrated. After drying out they often have a shorter life span and more drift. Higher pH solutions and slurries often foul the bulb and require a rinse with mild acid solution before rinsing with water and re-calibrating.

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