In the processing of all kinds of non metal mineral processing, the equipment used is mostly metal material, so it is easy to mix the indefinite foreign iron in non metal semi-finished products, which is generally called mechanical iron. For non-metallic mines with relatively strict iron content, this part of mechanical iron is a harmful component and must be removed by suitable process.
There may be obvious differences in the properties of mechanical iron, which is mainly reflected in the grain size and magnetic strength of mechanical iron, which has a certain influence on the process and equipment selection of mechanical iron removal.
Mechanical iron is derived from mineral processing equipment and auxiliary equipment. In the mineral processing equipment, the mechanical iron is mainly from the crusher grinding equipment, especially the grinding equipment. The iron in these equipment is the main source of the normal wear in the mineral processing and the iron produced by the equipment itself, while the iron in the auxiliary equipment is mainly the equipment oxygen. The formation of corrosion.
For mechanical iron mixed with non-metallic minerals, it is easy to remove coarse-grained particles, and the oxidized fine iron oxide minerals are difficult to remove.The main processes for removing mechanical iron include magnetic separation, classification and acid treatment.
Magnetic separation is the main way to remove mechanical iron, because most non-metallic minerals need magnetic separation and iron removal in the production of fine-grained products, especially fine particles or powders. So most of the mechanical iron can be removed together with the iron mineral impurities in the original ore.
The magnetic properties of mechanical iron are distinctly different because of the different materials used in the mineral processing equipment. For example, the lining board and jaw plate of the jaw crusher are mostly high manganese steel, and the lining plate of the mill has been using ZGMn13. Now it is gradually replaced by the alloy lining plate, but the lining plate used in some non-metal grinding industry is still the ordinary steel material. Only from the material, only from the magnetic point of view, most of the mechanical iron magnetic strong, the use of weak magnetic separation to achieve a good removal of iron effect, but for weak magnetic mechanical iron, such as high manganese steel, magnetic weak, the need to use strong magnetic separation can be removed.
For the micro fine-grained iron oxide, when the finished product requires coarse grain, the non metal minerals after magnetic separation can be removed by classification. The equipment used can consider the cyclone, high frequency vibrating screen, hydraulic classifier and so on.
A very small amount of ion type iron can be produced from the external mechanical iron. This part of the iron is low in general content or can be removed at the same time when the product is dehydrated. When the product is very high in iron requirement, acid treatment can be considered, and the iron content can be reduced by pure water or deionized water.
For the high hard nonmetallic minerals, such as quartz with low iron content but high hardness, the iron content of the ore itself is low, and the mechanical iron mixed with the outside is the main source of iron in the finished product. By removing the mechanical iron, the high quality products with low iron content can be obtained.