Performance Characterization And Preparation Process Design Of Silicon-smelting Coal Reducing Agent

Carbonaceous reductant that industrial silicon used for smelting is mainly based on charcoal,coal and petroleum coke.When we use the materials,we mix them up.Practical experience has shown that when charcoal contains 60%?80%good technical and economic indicators will be shown.Abundant use of charcoal limits development of industry of industrial silicon production units also are in urgent need of using the new smelting silicon reductant to replace charcoal.In this paper,the writer uses experimental research,makes use of yunnan local bituminous coal,after deferrization and de-ashing,I get clean coal with low iron and ash;By bonding petroleum coke and anthracite to form a pattern,finally I get coal reductant of neat granularity silicon smelting.This paper provides measurement method for each performance index of coal reductant,and makes use the existing index of reducer as the reference to make comparasion and analysis,various factors that influence the index of coal reducer are analyzed.When adding ingredients,on the premise of guarantee the intensity,scale of coal ash and iron of reductant can be adjusted by batching.Controlling appropriate volatilization can obtain ideal resistivity and reactivity.Coal reductant has a higher reactivity than that of ordinary coke.Experiments on choosing coal adapt flotation and magnetic separation combined deferrization and de-ashing,the best experimental conditions can be obtained by orthogonal experiment of flotation and magnetic separation respectively.The best flotation experiment conditions:pulp density 75 g/L,collector dosage 750 g/t coal,Foaming agent 100 g/t coal,coal particle size-0.125 mm,aeration rate 0.30 m3/(m2·min).The best magnetic separation experiment conditions:Coal slurry flow 100 L/h,coal particle size-0.125 mm,magnetic intensity 1.3 T,pulse times 0 times/min.Under the optimum experiment condition,joint experiment of magnetic separation and flotation can be carried out.Joint experiment investigates influence of different sequence of the flotation and magnetic separation can be made about the result,thus according to the experimental results,the lab technician knows that after combined process of flotation before magnetic separation should be chosen.Bituminous coal N within which ash contains 9.17%and iron contains 0.30%after the above mentioned joint experiment,I get 52.71%clean coal,with ash reducing to 4.18%,iron reducing to 0.09%.Molding of coal reductant examines the cold forming and hot pressing molding.Cold pressing molding is abandoned due to being unable to meet the needs of heat intensity.By hot pressing molding experiment,when bituminous coal ratio is in a range of 40%?60%,it can achieve good compressive intensity.Under the same molding conditions,the highest intensity can be obtained when batching bituminous coal and anthracite is made 6:4,bituminous coal and petroleum coke is made 5:5.Coal reductant molding experiment concluded that the main technological conditions of the terminal heating temperature is 800 ?,holding time 1 h,the heating rate is 5 ?/min,bituminous coal ratio is 40%?60%,the particle size is-0.125 mm,under the experimental condition,longitudinal compressive strength of coal reducer are higher than that of the charcoal.According to the formed experiment condition,forming of coal reductant uses solid heat carrier and technology of hot briquetting process.Design coal preparation process and forming process are chosen respectively according to experimental results.Through economic accounting,making coal reductant preparation is of certain economic benefit and ecological benefit which is conducive to the popularization and application.