Research On Substitution Of Wood Reducing Agent In Industrial Silicon Productio

With the increasing demand of metallurgical silicon and chemistry silicon,the production of industrial silicon obtained more and more attention.In recent years,China’s industrial silicon production capacity of over 4 million tons,but charcoal was still the main reducing agent as the production of silicon.According to statistics,every 5 tons timbers would be used to product one ton industrial silicon in the production.As more and more austere environmental situation,the action which is deforestation will be restricted.Therefore,in the industrial silicon industry,an increasingly important issue is that charcoal to be replaced by a new study reductant.In this paper,a comprehensive the substitution status quo analysis of the domestic and foreign industrial silicon smelting reducing agent,it was the principles was proposed that is for low ash bituminous coal flotation deliming-add a small amount of powdered charcoal,petroleum coke and cold forming-smelting in the furnace based on the principle of industrial silicon smelting and flotation and pressure group.In the process route,first of all low ash bituminous coal was cleaned by the tests of flotation.The results show that the coal ash can be reduced to 3.11%and the productivity up to 42.16%when the particles of bituminous-0.075mm accounted for 80%of the grain,coal slurry concentration of 100g/L,diesel fuel and 2#oil of 300g/t and 100g/t,sodium silicate of 2000g/t,stirring speed of 1800r/min,inflatable volume of 0.25m3/h,and using the process of a coarse and two sperm sorting.It can meet the requirements of ash in the furnace smelting.In the experiments of mixed the coal and petroleum coke and charcoal for Agglomeration,it focused on the relationship between the molding process parameters such as pressure,moisture,amount and type of binder,particle size,drying methods,materials and the briquette quality.Firstly,the effect of molding pressure,the use level of moisture,the dosage of binder and the material granularity on the performance of clumps was investigated by orthogonal,and then the parameters also were optimized by single-factor test.The results show that when coal:Petroleum coke:charcoal was 7:3:1,the forming pressure of 20MPa,the use level of moisture of 10%,the dosage of composite binder X of 5%,among petroleum coke and charcoal a particle size of 180～250μm,250～380μm,830～1000μm,1000～4750μm,etc.accounted for12.5%,and the section of 380～830μm accounted for 50%,silica fume of 6%the briquette cold strength was 6700N/a,thermal strength was 1213N/a,the porosity was 20%,the electrical resistivity was 928μΩm and the chemical activity could be closed to 53%under 1100℃.It researched the performances of several adhesives such as sodium silicate,modified sodium silicate,sodium humate,corn starch,wheat starch,potato flour,alkalization corn flour,oxide corn flour,corn stalks,wheat straw,rice straw and modified rice straw,etc.in the experiments of agglomerates.The results showed that the effect was poor for a single organic or inorganic binder to product the agglomeration,and it achieved a favourable indicator when some composite binders was elected for instance the sodium silicate-humic acid,sodium sodium silicateSodium Humate-alkalized corn flour,sodium silicate-sodium humate-modification of straw and so on.The binder which included sodium silicate,sodium humate and alkalized corn flour could get the best effect among the three binders in the experiment of agglomerates production and when the composite binder of 6%,the radio of three binders of 3:7:2,it achieved the satisfactory experiment index as follow:the dry-bulb strength of agglomerates of 4434N/a,the wet bulb strength of 1135N/a,the hot strength of 904N/a,the falling strength of 86.7%,the thermal stability of 95.1%,the porosity of 25.8%,the electrical resistivity of 937.8μΩm,the chemical reactivity of 58.1%under 1100℃.The results of dried test of briquettes showed that to make the briquettes dried sufficiently,it need 3 hours under 180℃,and it need 2 hours under 200℃.then it need nearly 10 days at room temperature.Finally,it did the experiment which thrown the new block reductant into the furnace and smelted utilizing the mixture of sodium silicate-sodium humatealkalized corn flour as composite binder to product briquette.The results showed that the effect was positive when use of the new composite adhesives to product briquettes for the reductant of industrial silicon production.The charcoal could be replaced 50%in the industrial silicon production,and the product could not only meet production requirements quality,but also reduce the power consumption.All in all,This process can effectively both reduce the content of harmful impurities Fe,Al,Ca that was took from the raw material in the furnace and improve furnace conditions and reduce production costs.