What Is a Concentration Meter?

Densitometer Concentration-The substance itself should be in solution in a solvent and soluble in the solvent. Under the premise that the measurement trend of the ultrasonic concentration meter is consistent with the actual concentration change trend of the ore processing plant, the measurement deviation meets 2.5%, and the practice has been successful. After long-term research and practice in the iron ore dressing plant, the ultrasonic concentration meter has truly served the field production, and the measurement accuracy meets the requirements of the production process, which has a good guiding significance for the metal mine dressing plant.

Aiming at the diversity of iron ore production processes,

1. Measure the properties of the medium

The properties of the measuring medium include the composition and proportion of the pulp, the size of the pulp, the instantaneous flow of the pulp, and the amount of bubbles in the pulp. The above factors play a guiding role in the technical indicators of the concentration meter.

2.Sensor selection

The selection of the sensor includes the measurement ability (measure the size of the ultrasonic frequency), the distance between the transmitter and receiver ends, and the wear resistance. The sensor selection must match the actual working conditions on site. The higher the degree of matching, the stronger the value of the measurement results.

3. Calibration and Calibration

Calibration and calibration include the validity of the calibration sample, the test accuracy of the calibration sample, the validity of the zero signal value of the ultrasonic concentration meter, and the correct selection of the measurement method. The calibration and calibration work has strong requirements on the technical staff's operating standards. The more rigorous the actual operation, the more impressive the results. ^[2]

The iron ore plant's main processing resources are magnetite, hematite (mirror) iron and limonite, followed by siderite, with trace pyrite, chalcopyrite, and cinnabar; gangue minerals are mainly quartz, magnesium iron Amphibole, actinite, talc, chlorite, and iron black hard chlorite, followed by carbonate minerals, including dolomite, calcite and so on.

When the sensor measurement interval is constant, the smaller the transmission frequency, the greater the measurement capability (the minimum frequency is 500 kHz); When the sensor measurement frequency is constant, the smaller the measurement interval, the greater the measurement capability (the minimum interval is 25 mm). The particle size and instantaneous flow of slurry flowing through the sensor directly affect the wear of the sensor.

Comprehensive analysis of the production process parameters and the measurement of the ultrasonic densitometer in practical production, the concentration measurement may be unstable or impossible to measure in the actual application of the ultrasonic densitometer, because the instrument measurement capability cannot meet the actual working conditions of this iron ore powder production line Claim.

In view of the above, the measurement frequency of the ultrasonic sensor was changed from the original 1 MHz to 500 kHz; the sensor transmission and reception pitch was changed from the original 100 to 293 mm to 25 to 80 mm; the material of the sensor probe was added with a wear-resistant coating on the stainless steel surface to Prevent it from wearing too fast ^[3]

There is a one-to-one correspondence between the ultrasonic density meter sensor and the converter. The corresponding parameters have been set in the converter circuit board in advance. Different sensors are not calibrated at the factory.

There is currently no verification procedure for ultrasonic densitometers in China. The calibration work is carried out by combining actual working conditions with the instrument's own calibration procedure. First, accurately measure the distance between the transmitter and receiver. The distance is millimeter level. During installation, a caliper and a measurement accuracy of 0 should be used. 001-class infrared rangefinder takes multiple measurements, takes the average value and sets the result in the converter; then calibrates the zero point signal value of the ultrasonic concentration meter. The factory calibration value of the concentration meter is performed in clean water and mud, which does not conform to iron. The environment of the water treatment plant and the slurry environment of the mineral processing plant needs to be recalibrated.

In order to make the curve as close to reality as possible, you need to take as many samples as possible, and the larger the difference in sample concentration, the better, such as the concentration value of the pulp is (0 ~ 5%), (20% ~ 25%), (40%) ~ 45%), (60% to 65%).

When production starts in the production pipeline, the water will ring, and the concentration of the pulp will gradually increase. After the production is normal, the concentration of the pulp will be stable. After research, samples were taken and tested under the circumstance that the water was circulated in the pipeline or the concentration of the pulp was low, and then the signal values were recorded; when the production was normal, the samples were tested and the current signal values were recorded.

Based on the two-point calibration, a three-point calibration is performed: the measurement value is the average value of the continuous sampling instrument measurement, the test value is the sample average value, and the deviation is the relative error between the test value and the test value. The accuracy of the artificial test value is generally 0.7%, and the measurement accuracy of the ultrasonic densitometer is 2.5%, which itself is related to the accuracy of the test value ^[2]

Under the premise that the measurement trend of the ultrasonic concentration meter is consistent with the actual concentration change trend of the ore processing plant, the measurement deviation meets 2.5%, and the practice has been successful. After long-term research and practice in the iron ore dressing plant, the ultrasonic concentration meter has truly served the field production, and the measurement accuracy meets the requirements of the production process, which has a good guiding significance for the metal mine dressing plant. Select the appropriate sensor frequency and spacing according to the on-site production process, factory zero calibration correction, three-point calibration equipment calibration, periodic calibration inspection and tracking comparison; through the research and practice of ultrasonic concentration meter in iron ore factory, further promote the ultrasonic The concentration meter is accurately measured and used stably in factories and mines ^[3] .