Introduction
1) The refinery deals with hematite hard rock, which contains iron minerals like pseudomorph hematite and semi-pseudomorph hematite. Gaugue minerals are mainly quartz,amphiboles, chlorite and etc. And their strip-shaped structure is quite obvious and disseminated particles are of very fine sizes. The fineness of the pseudomorph hematite and the quartz is generally 0.02-0.2mm. They should be grinded to 200 mesh with a percentage of 80%(g/t)first; add the 20% water solution to the ball mill at the second stage; then comes to the flotation process: PH value should be 8.5-9.5; the temperature of ore pulp should be 30-33℃; the collecting agent should be the mixture of oxidized paraffin soap 390g/t and tall oil 130g/t. And, gravity separation is mainly used for selecting hematite with weak magnetism.
2) Its two applications: first situation: when the mineral bed has high ore grade (about 50%), but the ore body is very thin or there are many interlayers; so during mining operation, stones may fall in, which causes ore loss; under this condition, the minerals only have to be crushed, then go to gravity separation to remove coarse tailings, which helps recover the high ore grade. Second situation: the materials are fine red iron ores or mixtures (red iron ores with weak magnetism and magnetite with strong magnetism); under this condition, the materials should be crushed and grinded to separate individual minerals, then go to gravity separation or the connected separation of magnetic separation and gravity separation, in order to get fine concentrates with high grade. This process is also called gravity separation for fine hematite ores.
Characteristics:
1) The most advanced solution to improve ore grade and recovery rate is by soaking, with a high grade of 63.9% and recovery rate of 65%-70%.
2) Selecting hematite in this way helps save electricity and equipment. This workflow is simple and efficient. Chemical reagent costs only 30 RMB (5 USD).Ferrous iron and ferric iron reduce to Fe3O4, which has strong magnetism and can be used in magnetic separation. The soaking time is 60 minutes. 
Henan Bailing Machinery Co., Ltd is specialized in manufacturing equipment for ore beneficiation. We are able to provide products for various ore beneficiation lines such as gold ore, copper ore, iron ore and manganese ore, etc. Our senior engineers are ready to offer the most suitable ore beneficiation solution for your production. Moreover, equipment installation and debugging, and training for technicians are provided free of charge. We are striving to satisfy your needs in every way. Please feel free to contact us if you are interested. Tel: 86-0371-67996061 
The above workflow is just for reference. The practical workflow should be designed according to the ore varieties and the chemical elements` contents relevant.