| Tin mineral resources are a relatively scarce resource.With the exploitation of people,the quality of tin mineral resources has been declining and the composition has become increasingly complex;the demand for tin on the market is very large and the price has remained strong;the market has consumed a lot of tin.Tin waste:It is particularly important to smelt tin-containing wastes to make up for the huge demand for tin in the market.The purpose of this design study is to use the submerged gun fusion technology,which is similar to Ausmelt's technology,to innovate the technology based on future tin resources.The design study uses tin-containing waste as raw material,designing the top-blowing smelting process to be divided into oxygen-enriched smelting stage and weak-reduction stage,and the Factsage software for slag type in each stage.The designed top-blowing furnace has an inner diameter of 3.2 meters,a 500-mm magnesium-chromium refractory brick in the middle,and a 40-mm steel shell at the outermost.It is 15 meters high and has a 200 mm wide(vertical)water-cooled tank every 180 mm from the foundation.Production scale:15.00t/h(dry basis).The material balance of the top-blowing furnace smelting process was studied to obtain crude tin with a tin grade of 54.5%.The tin yield was 65.92%,which contained 27.4%lead.And13.38%of the thorium;smoke dust rate was 13.2%,quartz flux consumption 0.949t/h,slag type of fayalite-based slag in the silicic acid degree is roughly 1.17,slag tin 8.13%.A material balance study was performed on the weak reduction process of the top-blowing furnace to obtain crude tin with a tin grade of 44.77%.The tin yield was59.47%,which contained 17.91%lead and 17.34%niobium;no quartz flux was needed.The slag type is mainly fayalite,the silicic acid degree in the slag is approximately 1.22,and the tin content in the slag is 2.91%.The total yield of tin was 75.72%,and the total dust and dust rate was 16.5%.The thermochemical study of the smelting stage shows that the flue gas volume is25310.52Nm~3/h,the secondary combustion air is 4586.04Nm~3/h,the intake air is1284.3Nm~3/h,the total natural gas is 1959.45Nm~3/h,and the fuel gas is 778.95Nm~3/h.The natural gas 1180.5Nm~3/h.The thermochemical study of the weak reduction stage shows that the amount of flue gas is 26,298.54 Nm~3/h,then the secondary combustion wind is 4702.59Nm~3/h,the intake air is 1579.5Nm~3/h,the fuel natural gas is 949.8Nm~3/h,and the reduction coal is 2.876t/h.Although the smelting stage and the weak reduction stage are unknown,they have been analyzed by Factsage theory.At the time of smelting,the reasonable temperature has been increased by 50°C for 1200°C and 1250°C respectively,and the temperature can be adjusted according to the actual smelting conditions.At this temperature,the corresponding viscosity of the two stages is 0.272Pa·S,0.245Pa·S;the silicic acid degree is 1.17,1.22;the density of the slag is 3.65g/cm~3,3.608g/cm~3;the slag melting amount is due to the smelting stage data Too large and not corresponding to the specific amount of melting,but the calculated total melting temperature of 1229.37°C,the smelting phase temperature requirements are not particularly stringent so 1200°C meet the melting temperature.In the weak reduction stage,the corresponding melting temperature accounted for 94.79%.High-temperature flue gas output from the top-blowing furnace:top-blown smelting furnace-waste heat boiler-surface cooler-bag dust collector-fan-chimney.The slag,which is weakly reduced in the top-blowing furnace,is treated with a fuming furnace to give a slag. |
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