Limonite Processing Plant - Iron Ore Processing

The treatment of limonite generally involves crushing and screening, ore washing, gravity separation or magnetic separation, and the grade of iron concentrate obtained is not high, and some even cannot obtain high-grade iron concentrate at all without beneficiation. The iron pit ore belongs to the refractory limonite type. Pit limonite is a deposit formed by the superposition of skarn iron sulfide and silicified limestone iron sulfide after later oxidation and other factors. The geological average grade (TFe) is 38.7%. In addition to limonite, there are also a small amount of hematite and magnetite in metal minerals. Non-metallic minerals are mainly quartz, followed by clay minerals such as kaolin and sericite.

The biggest feature of the ore is that it contains mud, contains high crystal water, is finely embedded, and is easy to muddy, and the grade of the fine-grained grade is higher than that of the coarse-grained grade.

1. Strong magnetic-positive flotation process

The grade of the coarse-grained grade in the tailings of strong magnetic separation is low, and the tailings can be discarded in advance to improve the grade and reduce the selection amount of the next operation. For this reason, a strong magnetic-positive flotation process is carried out. The raw ore classification magnetic-flotation process, magnetic Experimental research on 3 kinds of processes including tail classification-positive floatation process. The test results prove that the test indexes of the three processes are close, because the classification equipment used is difficult to solve the particle size classification problem of -0.074~+0.050mm, and the existing technology still has great difficulties in the recovery of fine particle iron minerals. However, it is reasonable to consider the strong magnetic-positive levitation (or high gradient magnetic separation) process from the aspects of technology and management.

2. Strong magnetic-positive floating-strong magnetic separation process

The flotation concentrate grade of the strong magnetic-positive flotation process contains TFe < 48%. In order to improve the grade of the flotation concentrate, the re-election process of the positive flotation concentrate is a positive flotation-high magnetic separation process.

Using positive flotation-magnetic separation in magnetic tail can obtain higher quality iron ore concentrate than single positive flotation process. The characteristics of this process: first use full flotation to ensure the recovery rate, and then use magnetic separation to improve the grade of iron concentrate.

3. Strong magnetic-reverse flotation process

The limonite concentrate grade is required to contain TFe>54% and SiO2<8%. The characteristics of this process: use the strong magnetic separation method to discard the tail and remove the mud to improve the recovery rate, and use the amine reverse flotation to improve the grade of the quartz. Test grinding classification - 0.074mm accounted for 70%, magnetic regrind classification - 0.05mm accounted for 85%.

4. Roasting-magnetic separation process

In the test, the roasting temperature is 650-700°C, the roasting time is 90 minutes, and the grinding fineness -0.074mm accounts for 70%-75%. Test results: When the raw ore contains 33.45% TFe, the obtained iron concentrate contains 58.48% TFe, the tailings contains 17.18% TFe, and the recovery rate is 68.87%, which is a good indicator.

Tiekeng limonite ore has complex properties, high mud content and high crystal water content. It is a red ore that is difficult to process. It is necessary to study and use efficient mineral processing equipment, efficient mineral processing agents and new mineral processing processes.