In recent years, China's economy has developed at a high speed, and the growth of the steel industry is also very rapid. The demand for ore by various steel companies is increasing. Domestic mine production has not met the demand for self-sufficiency, and it is necessary to introduce high-quality and high-priced iron ore resources from abroad. China has many types of iron deposits, and there are many types of ore. The content of harmful substances such as sulfur, phosphorus and silica is high, which accounts for a large proportion, and the distribution of useful substances is fine. This increases the difficulty of mining and selection, so it is inefficient. Product quality is also poor. In order to improve the supply of high-quality iron ore raw materials in China's steel industry, experts must use technology as a weapon to efficiently develop and utilize China's iron ore source.
Among the domestic iron concentrate production, magnetite concentrate accounts for about 3/4. In recent years, the magnetite ore dressing technology has greatly improved the production index. The steel industry has higher and higher requirements for raw materials. The application of magnetic separation equipment and the reverse flotation process are the main directions of “lifting iron and reducing silicon”. Selected mines are also a major part of iron ore beneficiation.
Magnetic separation equipment
Magnetic agglomeration reselector
An appropriate magnetic field intensity distribution is formed throughout the sorting zone of the device, a relatively uniform weak magnetic field, and a small magnetic field gradient. The separation of magnetic particles and gangue particles depends mainly on the magnitude of gravity and rising water flow.
Shougang Mining Company has developed a variable-diameter magnetic agglomeration re-selection machine and an electromagnetic gathering machine, which have been applied in Shougang Water Plant and Dashihe Iron Ore Concentrator.
The magnetic separation column is a weak magnetic agglomerate formed by the magnetic part of the fed material under the weak magnetic field moving downward under the combined action of magnetic force and gravity, and the gangue mixed therein moves upward under the action of the rising water flow. The magnetic agglomerates are subjected to multiple panning during the downward movement. The taste is gradually improved. The equipment has been applied in Bengang Nanfen Concentrator and Shantoushan Concentrator, and Jilin Banshigou Concentrator. Developed by Anshan University of Science and Technology.
The pulse vibrating magnetic field magnetic separation column developed by Northeastern University forms a vibrating magnetic field that continuously "moves" from top to bottom in the coil. The combination of a strong "vibration" magnetic field and a strong rising water flow can substantially eliminate magnetic inclusions and greatly increase the grade of iron concentrate. It has been applied to the selection of boron-containing iron ore in Dandong and the production of super iron concentrate in a factory in Chaoyang.
Low field strength self-weight jig
The mineral processing of Beijing University of Science and Technology is the research room after years of efforts to develop a low-field-strength self-weight jig, combining magnetoelectricity, jigging and heavy medium dressing. The 300mm small equipment developed has improved the iron concentrate grade of Shougang Waterworks Concentrator.
Low field strength pulsation
The low field strength pulsating magnetic separator is developed by Maanshan Mine Research Institute. It features: the magnetic system has a large number of large angles; the magnetic induction intensity is low and it is unevenly distributed from the sweeping area to the concentrate discharge area from high to low; There is a permanent magnet pulsation device, which can form a permanent magnetic pulsating magnetic field on the surface of the rotating cylinder to loose magnetic agglomeration and remove the mixed gangue. The Jiugang concentrator and the Angangshan Dagushan concentrator have each used it for successful industrial trials.
The BX multi-pole magnetic separator was developed by Baotou New Materials Application Design Institute and applied by the Gongchangling Concentrator.
Application of magnetite reverse flotation process
The upgrading of the magnetite concentrate with gangue is siliceous. De-flotation desiliconization is a good way. The Jianshan Concentrator, Maanshan Mine Research Institute, Gongchangling Concentrator and Lunan Mining Company Concentrator have all upgraded the magnetite, indicating that they have achieved good results.
Wuhan University of Technology has developed a new low-temperature cationic collector GE-601, which overcomes the shortcomings of foaming, foaming, foaming and difficult foaming.
Progress in hematite beneficiation technology
Hematite ore is an important iron ore resource in China. In recent years, the successful development and application of new processes, new equipment and new pharmaceuticals have made a major breakthrough in hematite beneficiation technology.
Slon vertical ring pulsation high gradient magnetic separator
The Luzhou Nonferrous Metallurgy Research Institute developed the Slon type pulsating high gradient magnetic separator. After more than 20 years of continuous improvement, it has good stability and good sorting properties, and is widely used in China's red ore dressing.
Angang Steel Station Concentrator, Qidashan Concentrator, Donganshan Sintering Plant, Panzhihua Iron Mine, Mi Mian Concentrator, Fujian Shanghang Lake Yangtie, Mine Kungang Dahongshan Concentrator, Mangyingou Iron Mine, Maanshan Gushan Iron Both the mine and Meishan iron ore have been operated with Slon models, which greatly improved the efficiency and quality.
Hematite reverse flotation process
Pre-hematite reverse flotation process: anion reverse flotation
The process was selected by Angang Steel Station Concentrator, Qidashan Concentrator and Donganshan Sintering Plant.
Development direction of iron ore beneficiation technology
1. Difficult to choose iron ore beneficiation technology
2. Pre-selection technology
The iron and steel industry plays an important role in the national exhibition economy. The efficient use of iron ore resources should be an arduous task for the ore dressing workers. Over the years, various domestic colleges and mining enterprises have done a lot of work in this respect: many achievements have been made in magnetite ore dressing technology and hematite beneficiation technology, and we need to strengthen complex and difficult iron in future life. The use of mineral resources to achieve an overall improvement in the use of iron ore resources.