| In this pilot study,phosphoric ore pulp was taken as the desulfurization agent to remove low concentration of sulfuric acid tail gas On the basis of laboratory experiments combined with,various influence factors of the pilot on the removal efficiency were investigated.This pilot study aimed to provide relevant data support for the industrial application of this technology.The results of laboratory experiments showed that SO2 reached saturation in distilled water only for 35 min,while the removal efficiency of SO2 still maintain more than 97%for 15 h using phosphoric ore pulp;To limestone and phosphoric ore pulp of contrast test,within 20 h of reaction time,the desulfurization efficiency of phosphoric ore pulp has been maintained in more than 95%,and limestone in response to 20 h,desulfurization efficiency has dropped to below 80%.It indicated that phosphoric ore pulp had the good potential for industrial applications.Desulfurization pilot test was carried out in Yunnan Phosphoric Chemical Group(YPC),and the test investigated the impact of various factors including the oxygen content,pH,pulp temperature,gas temperature,ore particle size,gas velocity,and spray volume.The result showed that 1)7%of the oxygen content of the exhaust gas can maintain the oxidation process,oxygen concentration increases did not improved the efficiency;2)As the reaction proceeds,the pH of the system slow down,and when the pH is less than 3 the removal efficiency will soon be reduced from the ideal removal;3)The effect of phosphoric ore pulp temperature desulfurization process was higher than the influence of gas temperature,when the temperature of the slurry was less than 35?,the removal efficiency was kept at a good value,when the slurry temperature is above 45?,the removal efficiency would decreased rapidly;4)The pilot system can adapt to changes in the normal range of agent added in the process of pulp preparation;5)Comprehensive comparison of the effects of different size powder on desulfurization found to increase ore particle size is conducive to desulfurization,but also brought a corresponding increase in energy consumption that the YPC of 200 mesh pulp used for the desulfurization process is appropriate;6)For different ore source but rather the extent of phosphate for analysis and found that the catalytic oxidation of metal ions with high content of the slurry is beneficial to improving the desulfurization efficiency;7)The increase of gas flow rate found detrimental to the desulfurization process,also found that higher gas velocity on the demister defoaming effect is favorable,but the growth rate will slow down the effect of demister;8)Penetration test found phosphate rocks on SO2 absorption capacity of 3.8×10-2g(SO2)/g(ore powder);Pilot study also provides the recommended parameters for subsequent industrial design.This pilot study showed that phosphoric ore pulp desulfurization technology had a good application prospects.It do not need to purchase additional desulfurization raw material and the product can be applied to the internal production process directly after desulfurization,causing no secondary pollutions,allowed enterprises to rationally,cost-effective removal of sulfur dioxide,and the export sulfur dioxide concentration is lower than 50mg/m~3,better than the national standard requirements of the discharge of less than 400 mg/m~3 requirements. |
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