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1

Selection of the best route for column configuration in an existing copper circuit

Can N. Metin, Altun Okan

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 2

552--564

EN

This study was aimed to utilize column flotation to obtain much cleaner concentrate in the Cu circuit. However, the numbers of equipment and the proper streams for column application should be the key for successful operation. Therefore, the effects of some operational parameters such as wash water rate, airflow rate and froth height were investigated on the streams of namely Cu first cleaner concentrate, Cu rougher concentrate and Cu third cleaner concentrate in terms of mineral recoveries and selectivity. Distribution of wash water rate to products was also determined by a tracer test method. Optimum operating conditions and accordingly performance of the column were determined by simulation studies. According to the results, the suitable streams for industrial scale flotation column are advised as the rougher concentrate and/or first cleaner concentrate. With series installation of columns, it is possible to obtain two different concentrates which include 22% Cu, 4% Zn and 17% Cu, 8% Zn without any decrease in overall recovery of plant.

2

Effect of pH and time on hydrodynamic properties of dodecylamine

Zhou X., Tan Y. H., Finch J. A.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 4

1237--1244

EN

Gas holdup and froth height in the presence of dodecylamine (DDA, pKa = 10.63) are reported at three pH values. The results revealed a strong time effect for DDA: stability was reached at pH 3; not at natural pH, for example, gas holdup declining to the water only value; and at pH 11, while stability was reached quickly gas holdup was now less than in water alone indicating coalescence. In the first two cases, the time effect is attributed to loss of amine from the system as molecular amine, observed at natural pH as precipitates on the column wall. An argument for precipitation at pH < pKa is presented. At pH 11, coalescence is attributed to the oily nature of the molecular amine present as colloidal aggregates. Noting a difference in literature steady state gas holdup data at natural pH, it is speculated that varying steady states can be reached that corresponds to different levels of amine loss.

3

Prediction of on-line froth depth measurement errors in industrial flotation columns: a promising tool for automatic control

Nakhaei F., Irannajad M.

Physicochemical Problems of Mineral Processing

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2013

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Vol. 49, iss. 2

757--768

EN

The pulp-froth interface position is important from a metallurgical point of view because it determines the relative importance of the cleaning and the collection zones. The pulp-froth interface position is measured based on variations of specific gravity, temperature or conductivity between the two zones to locate the pulp froth interface position. In this study, the pressure measurements are used to calculate the values of the froth layer height. These two meters are installed in the upper part of the column at 1.4 m and 2.4 m respectively, from the top of the column. Methods using pressure gauges are commonly used in industrial operations Even though their accuracy is limited (due to assumptions of uniformity of the pulp and froth density), and they always have some error. In the Sarcheshmeh copper industrial plant (Iran), a float was installed near the column with 2.5 m height that was calibrated to 5 cm intervals in order to determine the more exact forth height and compare it with the recorded froth height in control room. In this paper, an algorithm based on Kalman Filter is presented to predict on-line froth height errors using two pressure gauges. This research is based on the industrial real data collection for evaluating the performance of the presented algorithm. The quality of the obtained results was very satisfied. The RMS errors of prediction froth height errors was less than 0.025 m.