磁铁矿铁磁性能解析及应用

Analysis and exploitation ferromagnetic properties of magnetite

探讨磁铁矿物理化学特性,研究单线圈阻抗检测方法,用其实现铁矿选矿工艺过程中全铁品位指标的在线自动监测.采用X射线衍射分析方法和电感耦合等离子体质谱方法表征磁铁矿原矿及铁精粉矿样的物相组成及化学成分.利用振动样品磁强计测试矿样的磁化强度、矫顽力、比磁化系数等磁学性能指标,解析磁铁矿的强磁性能,应用其铁磁特性探讨交流激磁、矩型电感线圈、磁铁矿铁芯等条件下全铁品位指标的电磁感应测量方法及测试机理.设计信息采集装置、信号调理电路以及PIC单片机控制系统,给出温湿度测试方法及温度补偿方案.实验测试结果表明:应用磁铁矿铁磁特性进行全铁品位指标电磁效应在线监测具备可行性,铁精粉干粉实验测试误差低于±0.5%,测量标准差为0.19%.

The physical and chemical properties of magnetite were examined,which formed the basis for the development of an impedance detection method of single coil for online automatic monitoring for total iron（ TFe） grade of iron ore during mining process. By using X-ray diffraction analysis method and inductively coupled plasma mass spectrometry（ ICP- MS） method,phase composition and chemical composition of raw magnetite samples and fine iron powder samples were characterized. Furthermore,magnetic property indexes such as magnetization intensity,coercivity,and massic magnetic susceptibility,were detected by using vibrating sample magnetometer,and ferromagnetic properties of the magnetite were analyzed. According to the ferromagnetism,the principle behind the electromagnetic induction detection method for TFe grade under the condition of AC excitation and rectangle inductance coil with magnetite iron core was researched. Moreover,data acquisition devices were developed,signal processing circuits were designed, and PIC single-chip microcomputer control system was debugged. At the same time,temperature and moisture measuring methods were investigated,and temperature compensation scheme was given. The experiment results show that TFe grade test error is below ± 0. 5%,with a standard deviation of about 0. 19%,and it is feasible and practicable for the online monitoring of electromagnetic effect of TFe grade by using ferromagnetic properties of magnetite.