River iron ore on the West Anhui Anhui, Tongling - natural area of high-quality iron ore as raw materials to produce Fanchang high purity iron concentrate can be summarized as the following three processes:
1) Magnetic-floating joint process. That is, the ore → grinding → cyclone classification → overflow weak magnetic separation → magnetic fine cation reverse flotation. This process is suitable for the selection of river iron sand. (2) Single magnetic separation process. That is, the ore → grinding → cyclone classification → overflow weak magnetic separation. This process is suitable for the selection of natural high quality magnet ore. (3) Stage grinding and magnetic weight combined process. That is, feeding, grinding, grading, grading, overflow, weak magnetic separation, weak magnetic tail magnetic separation, strong magnetic coarse grinding, grading, and gradual overflow shaker re-election. This process is suitable for the selection of natural high quality mirror iron ore.
2 Effective ways of product development and utilization
Preparation of permanent ferrites At present, the main raw materials for producing permanent ferrites in China are iron scales and iron oxide red. The iron scale is mainly derived from various oxides formed by oxidation during the process of heating and rolling steel. Since the material of the rolled steel material changes frequently according to market requirements, the composition of the scale is fluctuated greatly, which brings great production to the ferrite. Difficulties, it is necessary to adjust the process parameters frequently, it is difficult to ensure the stability of product performance, under the current production conditions, it is difficult to produce high-performance products [3]. Although iron oxide red (Fe2O3) has high purity, it can produce high-performance ferrite. However, due to the high price of raw materials and limited market supply, it is difficult to reduce the cost of the product and ensure the normal production. In order to improve the performance of magnetic materials and reduce costs, it is necessary to select high-quality and low-cost raw materials. In the 1980s, Songling Mining Machinery Co., Ltd. began to study the use of ultra-pure iron concentrate produced by river iron sand to produce permanent ferrite. In the 1990s, it began to study the use of natural iron ore to produce ultra-pure iron concentrate to produce permanent ferrite. And succeeded.
The main process flow of using ultra-pure iron concentrate to prepare permanent ferrite is: feeding→recipe→primary ball milling→pre-burning→secondary ball milling→forming→sintering→product performance test
Studies have shown that compared with iron scales, the use of ultra-pure iron concentrate produced from river iron sand or high-quality natural iron ore as raw material to obtain permanent magnet materials has the following advantages:
(1) The composition of ultra-pure iron concentrate is stable, and its process conditions and product quality are relatively stable. The composition of the scale varies with the rolling steel, which affects the stability of the process and performance. (2) Ultra-pure iron concentrate has fine particle size and good activity, relatively in comparison
At low temperatures, it can be oxidized to Fe2O3 to produce excellent permanent magnets, which can reduce energy consumption compared to iron scales. (3) The particle size is fine, the wearability is good, and the ball milling time can be shortened. (4) The utilization rate is 10% to 20% higher than that of the iron scale, and the yield of the product is large.
Preparation of Powder Metallurgy with reduced iron powder
Powder metallurgy has the processing characteristics of less and no cutting, and is an effective means for manufacturing special materials and special products. The development of powder metallurgy technology is of special significance for material saving, energy saving and cost reduction [4].
At present, the raw materials for the production of reduced iron powder for powder metallurgy in China are basically steel oxide scales (ie iron scales). Similar to the above-mentioned pre-existing: ultra-pure iron concentrate ore dressing process and its effective way of development and utilization, the steel oxide scale is limited by the material of the steel, and its chemical composition is not ideal and fluctuates greatly. Therefore, in recent years, high-quality iron concentrate powder with high iron content has been used as raw material in China to test and produce such reduced iron powder.
The process of preparing reduced iron powder from ultra-pure iron concentrate is as follows: after the ultra-pure iron concentrate is filled, the tunnel kiln is initially
After reduction, the sponge iron ingot is obtained, and after the steps of cleaning, crushing, sieving, magnetic separation, annealing and fine reduction, the reduced iron powder for powder metallurgy is obtained. The obtained refined iron powder is prepared, mixed, shaped and sintered to prepare various iron-based powder metallurgy parts.
The beneficiation process for preparing ultra-pure iron concentrates from river iron sand and natural high-quality magnetite has been applied in industry. The beneficiation process of ultra-pure iron concentrate from natural high-quality specular iron ore is affected by unfavorable factors such as large fluctuations in raw material composition, low concentrate yield and long process flow. It is not very mature, and research should be further strengthened to resolve the contradiction between the supply of high-grade iron and red raw materials.
AOM (Acousto-optic Modulator)
It belongs to the high-speed acousto-optic Pulse Modulator which realizes the intensity modulation over the Laser according to the inputted pulse signal and gets corresponding digitally coded optical signal by inputting the digital signal of different codes and frequencies (TTL/ Analog) into the driving power supply of modulator. It is mainly used in such fields as laser text-image processing and laser digital communication.
This product has such characteristics as quick modulation rate, small volume, high efficiency, high extinction ratio, easy coding and convenient use.
Shutter
Cost-effective mechanical shutter, with repetition rate maximum 10 Hz. The valid output power is up to 3W available. The rise and fall time can be lower to 0.7 ms. Delay time is minimum 5 ms.
Pulse Modulator,Pulse Width Modulation,Pulse Frequency Modulation
Changchun New Industries Optoelectronics Technology Co., Ltd. , https://www.lasersciences.com