功率控制在磨矿分级自动控制系统中的应用

Application of Power Control in Automatic Control System of Grinding and Classification

随着国民经济的发展,各行业对资源的需求越来越大。我国是资源大国,同时也是资源贫国,绝大多数资源品位低,不能直接开发利用,必须通过选矿富集才能进入后续作业,故“选矿”在我国国民生产过程中占有十分重要的地位。磨矿分级是选矿生产流程中的关键环节,也是能耗大户,其生产成本和效率影响到选矿企业的各项经济技术指标,如何提高磨矿分级效率、降低磨矿分级成本是众多生产企业研究的课题。选矿自动化是降低选矿生产成本、提高选矿经济效益的重要手段,在选矿生产过程中得到广泛运用,尤其是磨矿分级自动化控制在提高选厂生产效率、降低生产成本方面效果明显,得到选矿企业的广泛重视。常规磨矿分级自动控制技术重在根据矿石性质的变化,自动调节磨机给矿量和给水量,当矿石易磨时增大磨机给矿量和给水量,矿石难磨时减小磨机给矿量和给水量,以提高磨矿分级效率,但同时也导致入选矿浆流量的波动,影响后续选别作业,引起选别指标波动,尤其是浮选作业。因此,在常规磨矿分级控制技术基础上引入磨机功率(转速)控制技术,进一步提高了磨矿分级效率,稳定了磨机给矿量和给水量,也稳定了入选矿浆流量,为后续选别提供了稳定的作业环境,优化了选别指标。

With the development of national economy,the demand for resources in various industries is increasing.China is not only a large country of resources,but also a poor country of resources,the vast.majority of low-grade resources can not be directly developed and utilized,which must be enriched through mineral processing to enter the follow-up operations,so mineral processing occupies a very important position in the process of national production in China.Grinding and classification is the key link in the mineral processing production process and a large energy consumption,its production cost and efficiency affect the economic and technical indicators of mineral processing enterprises.How to improve the grinding and classification efficiency,reduce the cost of grinding and classification is the subject of many production enterprises.Beneficiation automation is an important means to reduce the cost of beneficiation production and improve the economic benefits of beneficiation,which is widely used in the beneficiation production process,especially the automatic control of grinding and classification has obvious effect on improving the production efficiency of concentrator and reducing the production cost,which has been widely valued by beneficiation enterprises.The automatic control technology of conventional grinding and classification focuses on automatically adjusting the ore feed and water feed of the mill according to the change of ore properties,increasing the ore feed and water feed of the mill when the ore is easy to be ground,and reducing the ore feeding and water feeding of the mill when the ore is difficult to be ground,so as to improve the grinding and classification efficiency,but at the same time,it also leads to the fluctuation of pulp flow,affects the follow-up separation operations,and causes the fluctuation of separation indexes,especially in flotation operations.Therefore,based on the conventional grinding and classification control technology,the introduction of mill power(speed)control technology further improves the grinding and classification efficiency,stabilizes the mill feed and water supply,also stabilizes the feed pulp flow,provides a stable working environment for the follow-up separation,and optimizes the separation index.