Hysteretic pH value control device and control method

Abstract

The invention discloses a hysteretic pH value control device and a control method. The control device comprises a reaction kettle, a liquidometer is arranged in the reaction kettle, a reaction liquid input pipeline and an acid liquor adding pipeline are arranged at the top of the reaction kettle, the acid liquor adding pipeline is connected with an acid liquor header tank, a solution output pipeline is arranged at the bottom of the reaction kettle, an acid liquor flow regulating valve is arranged on the acid liquor adding pipeline, a pH value meter is arranged at the tail end of the solution output pipeline, and the pH value meter, the acid liquor flow regulating valve and the liquidometer are connected with a PLC. The problem that in the production process of a copper removal agent, due to fluctuation of the pipeline flow, insufficient partial solution mixing in the reaction kettle and a dynamic system, pH value control is hysteretic is solved, the flow of added acid liquor can be accurately controlled according to liquid level changes in the reaction kettle, and the purpose of accurately controlling the pH value of the reaction solution is achieved.

Description

technical field [0001] The invention belongs to the technical field of nickel electrolysis production, and in particular relates to a hysteresis pH control device and a control method. Background technique [0002] In the production process of nickel electrolysis, the nickel electrolyte needs copper removal treatment, and in the process of copper removal reaction, because the pH of the system plays a decisive role in the effect of the reaction, the pH value of the system is required to be maintained at a constant level. Therefore, it is necessary to accurately control the pH of the nickel electrolyte before the copper removal reaction. The pH value of the nickel electrolyte is relatively high before entering the copper removal reaction process, and sulfuric acid is generally used to adjust the pH. In the actual production process, on the one hand, affected by the previous filtration process, the nickel electrolyte flow rate of the pH adjustment reactor before entering the c...

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Problems solved by technology

In the actual production process, on the one hand, affected by the previous filtration process, the nickel electrolyte flow rate of the pH adjustment reactor before entering the copper removal reaction process is not a stable value, and the liquid output is a constant value. The change of the system flow rate makes the adjustment of pH There is hysteresis, which increases the difficulty of pH control; on the other hand, the production of the pH adjustment reactor is a continuous process, except that the pH adjustment reactor has liquid outlet while entering the liquid, and the volume of the pH adjustment reactor is relatively large. The hysteresis of the reaction system is relatively large, which further increases the difficulty of pH control

Based on the above reasons, it is difficult to control the pH of the copper removal reaction solution at the required constant value

Since the flow rate of the nickel electrolyte entering the pH adjustment reactor is gradually decreasing, the pipe used to transport the nickel electrolyte is not full of pipes, and the flowmeter has a large measurement error when the pipe is not full, which makes it difficult to pass the calculation. How to determine the amount of sulfuric acid added by the flow rate of nickel electrolyte

The current operation method directly connects the pH meter with the sulfuric acid adjustment control valve, adjusts the opening of the sulfuric acid addition valve through the pH setting value, and then controls the amount of sulfuric acid addition, but this method is difficult to solve the problem of pH adjustment control hysteresis, except The pH value of the copper reaction solution still cannot be accurately controlled

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