基于控制周期计算的锌液净化除铜过程优化控制
Optimal control based on control period calculation for copper removal process of zinc solution purification

净化除铜过程是锌直接浸出冶炼工艺中硫酸锌溶液净化的第1个步骤, 其效果直接影响着后续工序的正常 进行以及最终锌产品的质量. 本文针对除铜过程中控制周期与锌粉添加量不确定性, 造成出口铜离子浓度波动大 及锌粉浪费等问题, 研究基于控制周期的除铜过程锌粉添加优化控制方法. 首先通过分析反应器中氧化还原电位 (oxidation-reduction-potential, ORP)与锌粉的时序变化关系计算除铜过程反应响应时间, 然后分析响应时间的统计 特性, 从而确定锌粉控制周期. 在确定控制周期的基础上, 采用基于控制周期的固定节点控制参数化方法, 从而将最 优控制求解问题转化为非线性规划问题. 最后, 采用状态转移算法对该非线性规划问题进行求解. 采集工业现场数 据进行实验证明了该优化控制方法的有效性, 为类似的净化过程的优化控制提供了新思路.
The copper removal process is the first step in zinc solution purification of direct leaching of zinc hydrometallurgy, and its result has a significant impact on the follow-up process and the quality of the final product. In the copper removal process, the undetermined control period and addition amount of zinc-powder always lead to the fluctuation of outlet copper concentration and the waste of zinc powder. In order to solve this problem, an optimal control strategy based on control period calculation for copper removal process is proposed. First, the sequential relationship between oxidationreduction- potential (ORP) and zinc powder is analyzed to calculate the response time of copper removal process, and then the control period is obtained by analyzing the statistical characteristic of response time. Next, the optimal control problem is transformed into a nonlinear mathematical programming problem by the fixed-node control parameterization method. Furthermore, the state transition algorithm is applied to solve the nonlinear mathematical programming problem. And the simulation results demonstrate the effectiveness of the proposed control strategy.