There are grain size requirements for carbon materials. The particle size is too fine, the flying loss and the loss caused by combustion in the furnace mouth are relatively large. The particle size is too coarse, the diffusion area in the furnace is not enough, and the distribution is not uniform, white aluminium oxide which is unfavorable for smelting. On the other hand, the carbon particle size should match the bauxite block size, otherwise segregation will occur. There is a corresponding relationship between the size of carbon particle and the capacity of electric furnace. If the capacity of electric furnace is large, the size of carbon material can be a little larger.
Suspended pneumatic conveying relies on the kinetic energy of high-speed airflow. The advantages of pneumatic conveying are: small body size, flexible pipeline laying; high conveying efficiency, low labor intensity, less dust flying; simple equipment, pink corundum easy to manufacture and install; simple operation, easy to realize control automation. Use other safety devices, such as over load slice into hydraulic loading basin, etc. this can improve work efficiency, and even ear discharge, less powder
Ore bodies are usually bedded, with stable thickness and composition along the strike. The thickness can reach 25m, and the extension can reach several kilometers. The mineral composition of bauxite is simple, which is composed of diaspore or diaspore and contains iron minerals, black corundum usually with oolitic structure and pisolitic structure. This type of deposit has a large scale, with reserves ranging from tens of millions to hundreds of millions of tons. Mediterranean countries and Germany, Yugoslavia, Hungary and other countries have such deposits.
When smelting in fixed furnace, operators should pay attention to carbon monoxide poisoning at any time. If they feel headache, dizziness, nausea and other mild symptoms, they should go to a place with fresh air and proper temperature for rest or seek medical treatment. In case of white aluminum oxide severe poisoning, emergency search shall be carried out: remove the patient from the poisoning site immediately; place the patient in a place with fresh air and convective ventilation; keep quiet and keep warm; for the patient whose breath has stopped but the heart is still beating, artificial respiration shall be carried out; inform the relevant personnel of emergency treatment.
Large crushing ratio and wide feeding range. A self grinder can complete the coarse, medium and fine crushing operations at the same time. The autogenous grinding machine does not use grinding medium, which can reduce the chance of corundum products mixed with ferroalloy. The shape of brown fused aluminum oxide abrasive particles is good, and the equiaxed shape is more than 90%. The equipment is highly automated, easy to manage and high in production efficiency. There is a certain degree of over comminution phenomenon, so the yield of grain size commonly used in the processing of finished products is slightly low.
The gas permeability method is based on such a principle to test the particle size. This method can only get an average particle size value, and can't measure the particle size distribution. This method is mainly used in the magnetic material industry. Scraper method: scrape the samples of brown aluminium oxide and white corundum onto the surface of a flat plate, observe the roughness, so as to evaluate whether the sample size is qualified. This method is used in coating industry. A qualitative granularity test method.
When the iron content is sufficient, the silicon content in FeSi does not exceed the saturation concentration, and the reaction can proceed smoothly. In fact, the reduction of white fused alumina depends on the carbon dissolved in iron. The solubility of carbon in ferrosilicon melt decreases with the increase of silicon content in ferrosilicon alloy. That is to say, silicon can expel carbon from ferrosilicon melt, and the reduction of silicon dioxide will be difficult if the concentration of carbon in the melt decreases.